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Chemical Hygiene Guide

I. Introduction

Temple University is committed to providing a safe and healthy work environment for its faculty, staff, students and visitors. The number of chemicals used at Temple is large and the procedures are numerous and requirements are too complex to design a set of rules that will cover and mitigate all potential hazards. However, there are certain general principles of safety that apply to all operations.

The information contained in this document and in the Environmental Health and Radiation Safety (EHRS) Handbook is designed to protect you, your students and others from potential health hazards associated with the use, handling, storage and disposal of hazardous chemicals in work areas. In addition, this information will assist you in complying with federal, state and local regulations and Temple University policies. This document is to be used in conjunction with your site specific chemical hygiene worksheet and the EHRS Handbook.

The EHRS handbook describes the roles and responsibilities of the Environmental Health and Safety Safety Committee (EHSSC) (EHRS Handbook 1.6) , Principal Investigators and Supervisors (EHRS Handbook 1.4), and the Chemical Hygiene Officer (EHRS Handbook 5.4). The Medical assessment and treatment policy is described in the EHRS handbook (EHRS Handbook 1.8). EHRS conducts periodic inspections (EHRS Handbook 5.5) to ensure compliance. Please visit the EHRS webpage for additional information.

II. The Chemical Hygiene Plan (CHP)

The Occupational Safety and Health Administration (OSHA) is the primary Federal regulatory agency that oversees compliance in laboratories. In January 1990, OSHA issued its final rule on compliance in laboratories. The requirements are identified in 29 CFR 1910.1450-Occupational Exposure to Hazardous Chemicals in Laboratories. Most labs at Temple are covered under this Lab Standard. According to the regulation, a Chemical Hygiene Plan must be developed and applied to all employers engaged in the laboratory use of hazardous chemicals. A “laboratory” is defined as a facility where the laboratory use of hazardous chemicals occurs.

The intent of the Chemical Hygiene Plan is to ensure that employees have working knowledge about the hazardous chemicals they use. Temple’s CHP consist of two main parts

  • The Chemical Hygiene Guide
  • The Chemical Hygiene Guide (CHG) Site Specific Worksheet

Each Supervisor, Principal Investigator (PI) , Department Head or Manager is responsible to review the following chemical hygiene guide and to use it in the development of a complete plan specific to their own laboratories. Each Supervisor, PI, Department Head or Manager is responsible for the implementation and documentation of his or her own Site Specific Chemical Hygiene Guide and for providing safety information and training to their employees. The Site Specific Chemical Hygiene Guide must be reviewed on an annual basis. The CHG worksheet template has been developed to assist you in meeting the requirements of your site specific chemical hygiene guide.

The CHG worksheet is intended to facilitate and assist you in the development and maintenance of laboratory specific documents and records. The CHG worksheet must be reviewed and updated on an annual basis. The CHG worksheet cover page must be completed and attached to the front of the worksheet on an annual basis.

Contact Environmental Health and Radiation Safety (EHRS) at 215-707-2520 or 2-2520 for a copy or visit OSHA’s web page.

It is important for you to be familiar with this document, the EHRS Handbook, your site-specific guide ( or worksheet) and to review both with your laboratory workers, and to follow all safety instructions. The EHRS contains additional information such as General Standard Operating Procedures (SOP) policies. The EHRS handbook can be accessed here.

The Temple University Chemical Hygiene Guide (CHG) is adopted from several sources. Much of the text is taken from publications from the National Research Council such as “Prudent Practices in the Laboratory-Handling and Disposal of Chemicals”. Other sources of information include various regulations of the Occupational Safety and Health Administration (OSHA), those of the U.S. Environmental Protection Agency (EPA), and publications of the International Agency for Research of Cancer (IARC) and others located in the EHRS conference room. All Federal regulations are listed in the Code of Federal Regulations (CFR) (such as OSHA, EPA, etc.) and can be found here.

III. Responsibilities of the Supervisor, Principal Investigator, Department Head or Manager

The Supervisor, (PI) , Department Head or Manager is responsible for the safe use of chemicals and for complying with applicable regulations and University policies and procedures. This responsibility may not be shifted to inexperienced or untrained personnel. You must ensure that:

  • An Hazardous Operation Surveillance Form has been submitted to EHRS.
  • if needed, an Assurance of Hazardous Procedures form(EHRS Handbook 1.3) is submitted prior to conducting an experiment;
  • if needed, license has been granted for select agents;
  • complete the CHG worksheet or develop and implement a site-specific chemical hygiene guide;
  • review and revise the CHG worksheet or Site specific CHG on an annual basis
  • Site Specific Standard Operating Procedures are developed and implemented for operations/experiments involving hazardous materials;
  • all laboratory workers do not exceed OSHA’s (29 CFR 1910.1000-Subparts Z-Toxic and Hazardous Substances) Permissible Exposure Limits (PEL) and the American Conference of Governmental Industrial Hygienist Threshold Limit Values (TLV);
  • all requirements in this Chemical Hygiene Guide (CHG) are followed;
  • laboratory workers and others entering the laboratory know and follow chemical safety rules;
  • ensures that adequate safety and emergency equipment is available and in proper working order;
  • information on special or unusual hazards in non-routine work has been distributed to the laboratory workers;
  • laboratory workers are trained in the use of all safety and emergency equipment;
  • proper lab attire is worn and a laundry service is provided for lab coats;
  • appropriate personal protective equipment is provided, is in working order and is used properly;
  • when respiratory protection is to be used, all personnel are trained on the use and limitations of the respirator, have a medical evaluation and have been fit tested on the respirator they are to wear. Contact EHRS to arrange for these services;
  • appropriate training is provided to all occupants of the laboratory when they are first assigned to a laboratory;
  • ensures that all hazardous chemicals are secure; and
  • unsafe acts, conditions, or inadequate facilities are reported to the Department Chair, Program Director and/or EHRS.

Furthermore, you are responsible for implementing and enforcing safe work rules in your laboratory(s). It is your responsibility to assure that the manufacturer’s safety data sheets (SDS) related to hazardous chemicals used in your laboratory(s) are readily available in the laboratory. You must adhere to all the safety instructions listed in the SDS related to work areas and to personal protective equipment that must be worn while working with specific hazardous chemicals. You must conduct periodic general safety and housekeeping inspections. The EHRS can assist you in setting up the proper safety procedures in your laboratory.

Each laboratory must display a room sign(s) that provides safety information to visitors and non-research support personnel. EHRS can supply the room sign(s) to you. You are responsible for providing accurate information to EHRS personnel so that they may display the correct information. You must inform EHRS when there is a change in the inventory or type of hazardous chemicals used in your area. You must submit a chemical inventory to EHRS on at least an annual basis.

In addition, you must assure that all laboratory workers have appropriate information and training related to your operation and presence of hazards associated chemicals. The Occupational Safety and Health Administration (OSHA) mandates this training in addition to the EHRS required training. You must assure that all new laboratory workers attend the EHRS Chemical Hygiene training (EHRS Handbook 3.3.). The refresher training must be provided if there is a change in type of hazards (with new processes or new chemicals) prior to work under the new conditions. The EHRS maintains a comprehensive library on reference materials and related information in the EHRS conference room. The EHRS conference room is located in room B-40 in the Pharmacy Allied Health building located on the Health Sciences Center campus. Please contact the EHRS at 2-2520 for additional information on training or reference material.

IV. Definition of Hazardous Chemicals and Hazardous Waste

Hazardous Chemicals

A hazardous chemical is a chemical for which there is statistically significant evidence (based on at least one study conducted according to established scientific principles) that acute or chronic health effects may occur in exposed employees, or if it meets one or more of the following:

  • any chemical which is a physical hazard or a health hazard (OSHA 29 CFR 1910.1200(c)) or 29 CFR 1910.1450(b));
  • any chemical for which there is scientifically valid evidence that it is a combustible liquid, a compressed gas, explosive, flammable, organic peroxide, pyrophoric, unstable (reactive), or reacts violently with water;
  • any chemical, for which there is statistically evidence based on at least one study conducted in accordance with established scientific principles that acute or chronic health effects may occur in exposed employees, is classified as a health hazard. Health hazards include chemicals that are carcinogens, toxin or highly toxic agents, reproductive toxins, irritants, corrosives, sensitizers, hepatotoxins, nephrotoxins, neurotoxins, agents which act on the hematopietic systems; and agents that damage the lungs, skin, eye or mucous membranes as defined in 29 CFR 1910.1200, Appendix A;
  • any chemical, for which the evaluation performed by the chemical manufacturer/importer, as listed on the Safety Data Sheet (SDS), indicates it is hazardous;
  • Any chemical listed in OSHA, 29 CFR 1910 Subpart Z, "Toxic and Hazardous Substances" or Environmental Protection Agency (EPA), 40 CFR Part 261 "Identification and Listing of Hazardous Waste.";
  • any chemical listed in the "Threshold Limit Values for Chemical Substances and Physical Agents in the Work Environment", American Conference of Governmental Industrial Hygienist (ACGIH) (latest edition) or "The Registry of Toxic Effects of Chemical Substances", NIOSH (latest edition);
  • any chemical regulated by the U.S. Department of Transportation, 49 CFR, Subchapter C, Parts 171-172;
  • any chemical that is capable of causing environmental or health damage if disposed of improperly as specified in the U.S. Environmental Protection Agency, Title 40 Code of Federal Regulations (Resource Conservation and Recovery Act); and
  • any mixture untested as a whole to determine whether it is a physical or health hazard is assumed to present the same physical or health hazard as the individual components that compromise one percent or greater ( by weight or volume) of the mixture. An exception is the mixture shall be assumed to present a carcinogenic hazard if it contains a component which is considered to be a carcinogen in concentration of 0.1 percent or greater.

In most cases, the labels indicate the type of hazards if the chemical is hazardous. Look for key words like “caution”, “hazardous”, “toxic”, “dangerous”, “corrosive”, “irritant”, or “carcinogen”. A label is any written, printed, or graphic material displayed on, or affixed to, containers of chemicals. Labels or other forms of hazard warnings, such as tags or placards, provide immediate warning of potential danger.

Hazardous Waste

Hazardous waste is any material that is unwanted and cannot be reused or is a spent chemical that must be disposed. Material that is still "good" or "reusable" is not hazardous waste. The Environmental Protection Agency (EPA) and the Pennsylvania Department of Environmental Protection (PADEP) are the primary agencies that regulate hazardous waste. Hazardous waste is material that meets one or more of the following definitions or is otherwise dangerous to human health and/or the environment:

  • Ignitability- Flash point < 60 °C (140 °F), spontaneously combustible, or oxidizer-40 CFR 261.21
  • Toxicity- 40 CFR 261.24
  • Reactivity- Unstable, water reactive, or explosive- 40 CFR 261.23
  • Corrosivity- pH £ 2 or ³ 12.5 -40 CFR 261.22
  • Specifically listed (F, K, P, or U lists) 40 CFR 261.31, 32 and 33 ;( Acutely hazardous wastes are designated by an H listed hazard code & all P listed waste.)

V. Laboratory Rooms

All Chemical Hygiene Plans should contain a current listing of all the Departments Key safety personnel. In addition, the Plan must contain a current listing off all labs, lab personnel, their lab room numbers and related phone numbers, These rooms include labs and other types of rooms such as temperature controlled rooms, storage rooms, storage closets (containing hazardous chemicals) and animal facilities that are subject to the lab standard. For “common” rooms which are shared by different groups, each group shall list all the rooms that they use and indicate a plan of primary responsibility for safety and compliance in the “common” rooms.

It is Temple University’s policy that a formal decommissioning be conducted prior to the renovation or transfer of ownership of lab space. Please see the Vacating Laboratory Space policy for addition information.

This information is to be updated yearly and kept on record with the CHG worksheet.

VI. Training

Everyone who works with or is exposed to potentially hazardous chemicals in a laboratory will receive training on the Occupational Exposure to Hazardous Chemicals in Laboratories Standard. The intent of training is to assure that all individuals are informed about hazards and protection when working in the lab.


Initial training is required upon assignment to the lab and includes basic orientation for lab chemical safety plus laboratory-unique information and training. Any individual who works with hazardous materials is also required to attend Hazardous Waste Training (Initial and an annual refresher). Basic lab chemical safety orientation training in classroom or online formats is available through EHRS. Training schedules and online training courses are found at on the EHRS Training web page. For more information contact EHRS at 215-707-2520. The Supervisor, PI, Department Head or Manager is responsible for ensuring that all employees attend the mandatory training prior to working with hazardous material. In addition, site specific training must be conducted by the Supervisor, PI, Department Head or Manager prior to working with hazardous material. A Site specific training template has been developed to assist you.

Additional training is also required when a new hazard is introduced or when there is a need. Supervisor, PI, Department Head or Manager will provide or arrange for the additional training. Examples of a new hazard may be physical or health hazards associated with chemicals, or operations for which prior training was not received. Examples of a need for additional training may be to improve work practices, address measures to prevent a spill or accident from occurring, or to provide training for work with highly hazardous substances. Labs are encouraged to routinely include chemical health and safety topics in lab meetings or other communications with employees.

Content of Required Training

    • Provisions of the Laboratory Standard.
    • The location and availability of the Generic Chemical Hygiene Guide and the Site Specific Chemical Hygiene Plan.
    • Review of all generals SOP’s and Lab Specific SOP’s
    • Hazardous chemicals in the work area.
    • Physical and health hazards of the hazardous chemicals in the work area.
    • Protective measures for handling hazardous chemicals used in the work area.
    • Proper chemical handling procedures for all classes of materials used.
    • Labels and hazard warnings.
    • How to locate, interpret and use Safety Data Sheets.
    • How to detect the presence or release of hazardous chemicals in the work area.
    • Legal and recommended exposure limits.
    • Correct use of engineering controls, personal protective equipment, and any other methods used to reduce or eliminate exposure.
    • Signs and symptoms of overexposure.
    • Medical services available.
    • A procedure for emergencies, spills and first aid.

A record of this training must be kept on file and available for review upon request. EHRS has developed a Site Specific training sheet to be sued to ensure your compliance with training. This information is to be updated yearly and kept on record win the CHG worksheet.

VII. Hazard Communication

Hazard Communication Standard

The purpose of this standard is to transmit the information concerning the hazard of the chemical sin the labs to the employees working with these chemicals. The standard can be found at 29 CFR 1910.1200, Please see the Temple University Hazard Communication program for additional information.

Hazard Identification

A hazardous chemical is a chemical that is capable of causing immediate or long term health effects to any potentially exposed employee. Refer to section IV for a complete definition of a hazardous chemical. The following sources of information are critical in identifying these chemicals.

  • Labels
    • Hazardous Chemicals- All chemical containers will have a primary pr secondary label identifying the contents and hazards. Many chemical containers are also labeled with either a National Fire Protection Association (NFPA) or a Hazardous Materials Information System (HMIS) diamond shaped label.
    • Hazardous Waste- All hazardous chemical waste containers must be labeled with a hazardous waste label which can be obtained through EHRS (215-707-2520). The label must eb affixed to the container and completed before you utilize the container.
  • Safety Data Sheets (SDS)
    • SDS are available through EHRS either via the EHRS SDS webpage or by contacting EHRS at 215-707-2520. Hard copies of SDS are located in the EHRS conference room at 3307 N. Broad Street, Room B-49, Phila, PA 19140. SDS can also be obtained through the chemical manufacturer.
    • SDS for specific area must be made readily available to all employees. Electronic copies are acceptable as long as employees have access whenever they are working in the area.
  • EHRS Library
    • The EHRS library has information and videos/DVD’s that are available for use. Please visit the EHRS training webpage for a listing of videso/DVD’s available for loan. Example of items that can be used include the following:
      • 29 Code of Federal Regulations (CFR) 1910.1000 Subpart Z
      • Threshold Limit Values (TLV’s) for Chemical Substances-distributed by the American Conference of Governmental Industrial Hygienists
      • Pocket Guide to Hazardous Chemicals-distributed by the National Institute of Occupational Health and Safety

Copies (unless stored electronically) of your SDS along with additional information on your labeling systems must be kept on file and available for review upon request. EHRS has developed a Site Specific training sheet to be used to ensure your compliance with training. This information is to be updated yearly and kept on record win the CHG worksheet

Chemical Inventory

Each Supervisor, PI, Department Head or Manager is required to maintain a current inventory of all potentially hazardous chemicals stored, used, or produced within each lab that is under his or her responsibility. An approved electronic copy of this inventory list must be submitted to EHRS on annual basis. Firefighting or other emergency personnel may not enter a laboratory without knowledge of the risks. Please see the Chemical Inventory policy for additional information.

A copy of the up to date inventory must be kept with the CHG worksheet and available for review upon request. EHRS has developed a Site Specific worksheet to be used to ensure your compliance with the inventory requirement.

Exposure Assessments and Medical Services

Many hazardous chemicals have defined exposure limits called Permissible Exposure Limits or PELs. These exposure limits can be based on an 8-hour Time Weighted Average (TWA) exposure, a 15-minute Short Term Exposure Limit (STEL), or an upper limit exposure (Ceiling). Where specific limits are given, the lab standard requires that employee exposures not exceed these limits. If an overexposure is suspected, an exposure assessment is necessary. If the assessment indicates that an employee could reasonably have been exposed to a hazardous chemical in a manner that might have caused harm, the person is entitled to medical services. Services include a medical consultation and, if determined to be needed, a medical examination.

  • Exposure Assessments
    The purpose of an assessment is to determine if there was an exposure that might have caused harm to lab employees and to identify the chemical(s) involved. Exposure assessments may include interviews with the affected employee(s) and laboratory staff, air monitoring, evaluation of laboratory controls and protective equipment, and medical consultation and examination. It is the responsibility of the Supervisor, PI, Department Head or Manager to ensure that an exposure assessment is conducted.

When to suspect overexposure If an employee manifests symptoms such as headache, rash, nausea, coughing, tearing, irritation or redness of the eyes, irritation of the nose or throat, dizziness, loss of motor dexterity or judgment, etc., and:

  • Some or all of the symptoms disappear when the employee is removed from the exposure area.
  • The symptoms reappear soon after the employee returns to work with the same hazardous chemicals.
  • Two or more persons in the same laboratory work area have similar complaints.
  • A hazardous chemical leaked, spilled or was otherwise rapidly released in an uncontrolled manner.
  • A laboratory employee had direct skin or eye contact with a hazardous chemical.

Note: Odor is not a means of determining exposure levels. If there is reason to suspect that a chemical exposure limit has been exceeded, notify the lab supervisor whether or not a suspicious odor is involved.

  • Monitoring for Hazardous Chemicals

Contact the Environmental Health & Radiation Safety (EHRS) to request air monitoring to evaluate chemical exposures. Upon completion of monitoring, employees must be notified of results in writing, either individually or by posting, within 15 days of the receipt of results. Records of monitoring results and employee notification must be kept, transferred, and made available in accordance with 29 CFR 1910.1020. If exposures are found to be over legal limits, further action will be required. Please see the Monitoring of Hazardous Chemicals policy for additional information.

  • Medical Services
    Medical services may consist of a medical consultation, examination, or emergency services. Pre-exposure (baseline) assessment is available upon departmental request at the Occupational Health. There is no cost to the employee for these services and employees may be medically monitored on an annual basis. Please visit Medical Monitoring policy for additional information.

When assessment results indicate that an employee may have been exposed to a hazardous chemical, the employee should obtain a medical consultation from the Occupational Health. Consultations and examinations must be under the direct supervision of a licensed physician. The employing lab or department must inform the physician of the identity of the chemical, the conditions of the exposure, and the employee's symptoms. A written opinion must be obtained from the physician. It must be maintained as a part of the employee's record and made readily available to the employee and upon request to his/her designated representative. The written opinion must not reveal findings unrelated to occupational exposure.

The written opinion must include:

  • Follow-up recommendations.
  • Exam and test results.
  • Any medical condition found as a result of the exam that may place the employee at an increased risk as a result of hazardous chemical exposure.
  • A statement that the employee has been informed by the physician of the results of the consultation.

Exposure and Medical Records
Records of monitoring measurements or any medical baseline, consultation or examination, including tests or written opinions, must be maintained for each employee for a period of thirty years after retirement or resignation. Such records must be kept, transferred, and made available in accordance with 29 CFR 1910.1020.

EHRS Safety Inspections and Lab Self-Evaluation

EHRS conducts periodic inspections to maintain compliance with the requirements of this standard. Please visit the Chemcial Safety Audit Program for additional information.

In addition, each lab/department is required to complete a self evaluation on an annual basis. The self evaluation forms must be completed by the Supervisor, PI, Department Head or Manager and be readily available for review upon request.

The records of any exposure assessment, monitoring, safety inspection, corrective actions, self evaluation any other related records must be recorded in the CHP worksheet and must be kept with the CHG worksheet and available for review upon request. This information is to be updated yearly and kept on record win the CHG worksheet

VIII. General Prinicples

It is extremely important that everyone involved in day to day laboratory operations, from the highest administrative level to the individual worker to be safety conscious. Public concern for safety in the work place and protection of the environment through pollution prevention has resulted in a voluminous array of regulations designed to control every stage of the transportation of chemicals to and from laboratories, their handling within the laboratory workplace, and their final disposal. Safe practice by laboratory workers requires attention and continuing education.

Over familiarity with a particular laboratory operation may result in overlooking or underrating its hazards. This attitude can lead to a false sense of security, which frequently results in carelessness. Every laboratory worker has a basic responsibility to himself or herself and colleagues to plan and execute laboratory operations in a safe manner.

Every laboratory worker (student or employee) must observe the following rules:

  • Know the safety rules and procedures that apply to the work that is being performed. Determine the potential hazards (e.g., physical, chemical, and biological) and appropriate safety precautions before beginning any new operation.
  • Obtain and review all the Safety Data Sheets (SDS) and Standard Operating Procedures (SOP) for each chemical prior to using.
  • Modify work procedures so that laboratory hazards are eliminated or minimized.
  • Food or beverages must not be consumed or stored in areas where hazardous materials are present.
  • Do not manipulate contact lenses or apply cosmetics in areas where hazardous chemicals are used or stored.
  • Know the location of and how to use the emergency equipment in your area, as well as how to obtain additional help in an emergency, and be familiar with emergency procedures.
  • Know the types of protective equipment available and use the proper type for each job.
  • Be alert to unsafe conditions and actions and call attention to them so that corrections can be made as soon as possible. Someone else's accident can be as dangerous to you as any you might have.
  • Know and follow proper waste disposal procedures. Chemical reactions may require traps or scrubbing devices to prevent the escape of toxic substances.
  • Laboratory doors must remain closed when experiments involving hazardous chemicals are being conducted.
  • Ensure that all chemicals are correctly and clearly labeled with chemical content and appropriate hazard warnings. Abbreviations and chemical formulae are unacceptable
  • Post warning signs when unusual hazards such as, laser operations, flammable materials, biological hazards, or other unique problems exist.
  • Remain out of the area of a fire or personal injury unless it is your (General Recommenda­tions for Safe Practices in Laboratories) responsibility to help meet the emergency. Curious bystanders interfere with rescue and emergency personnel and endanger themselves.
  • Avoid distracting or startling any other worker. Practical jokes or horseplay cannot be tolerated at any time.
  • Use equipment only for its designed purpose.
  • Inspect equipment or apparatus for damage prior to use
  • Never use damaged equipment
  • Electrical extension cords are not used as a permanent source of electric
  • Never leave experiment running unattended if there is any potential hazard associated with it (ex. Flood, fire, etc.)
  • Electrically ground and bond containers using approved methods before transferring or dispensing a flammable liquid from a large container
  • position and clamp reaction apparatus thoughtfully in order to permit manipulation without the need to move the apparatus until the entire reaction is completed. Combine reagents in appropriate order, and avoid adding solids to hot liquids and
  • think, act, and encourage safety until it becomes a habit.

Health and Hygiene

Laboratory workers must observe the following health practices:

  • Wear appropriate eye protection at all times.
  • Always wear a clean lab coats in any area where hazardous materials are used or stored.
  • Use required personal protective equipment, including face shields, gloves, and other special clothing or footwear as needed.
  • Confine long hair and loose clothing; do not wear opened toed shoes or shorts when working in the laboratory.
  • Do not use mouth suction to pipette chemicals or to start a siphon; a pipet bulb or an aspirator must be used to provide vacuum.
  • Never smell, inhale or taste a hazardous chemical
  • Avoid direct contact with any hazardous chemical
  • Avoid exposure to gases, vapors, and aerosols. Use appropriate safety equipment whenever such exposure is likely.
  • Always use chemicals with adequate ventilation or in an approved chemical fume hood. Refer to SDS for proper procedures
  • Wash well before leaving the laboratory area. Wash thoroughly with soap and water after handling any chemical. However, avoid the use of solvents for washing the skin. They remove the natural protective oils from the skin and can cause irritation and inflammation. In some cases, washing with a solvent might facilitate absorption of a toxic chemical.

Equipment Maintenance

Good equipment maintenance is important for safe, efficient operations. Equipment must be inspected and maintained regularly. Servicing schedules will depend on both the possibilities and the consequences of failure. Maintenance plans must include a procedure to ensure that a device that is out of service cannot be restarted.

A record of all equipment inspections and maintenance must be kept on file and available for review upon request. EHRS has developed a Site Specific training sheet to be sued to ensure your compliance with training. This information is to be updated yearly and kept on record win the CHG worksheet

Food Handling

Contamination of food, drink, and smoking is a potential route for exposure to toxic substances. Food must be stored, handled, and consumed in an area free of hazardous substances.

  • Well-defined areas must be established for storage and consumption of food and beverages. No food is to be stored or consumed outside of this area.
  • Areas where food is permitted must be prominently marked and a warning sign (e.g., EATING AREA‑‑NO CHEMICALS) posted. No chemicals or chemical equip­ment is allowed in such areas.
  • Consumption of food or beverages and smoking must not be permitted in areas where laboratory operations are being carried out.
  • Glassware or utensils that have been used for laboratory operations is never to be used to prepare or consume food or beverages. Laboratory refrigerators, ice chests, and cold rooms are never to be used for food storage; separate equipment must be dedicated to that use and promi­nently labeled.


There is a definite relationship between safety performance and orderliness in the laboratory. When housekeeping standards fall, safety performance inevitably deteriorates. The work area must be kept clean, and chemicals and equipment must be properly labeled and stored.

  • Work areas must be kept clean and free from obstructions. Cleanup must follow the comple­tion of any operation or at the end of each day.
  • Wastes must be deposited in appropriate receptacles.
  • Spilled chemicals must be cleaned up immediately and disposed of properly. Temple University has established disposal procedures for the disposal of chemical waste and prompt laboratory accidents clean up.
  • Unlabeled containers and chemical wastes must be disposed of promptly, by using appropriate procedures. Such materials, as well as chemicals that are no longer needed, must not accumulate in the laboratory.
  • Floors must be cleaned regularly; accumulated dust, chromatogra­phy adsorbents, and other assorted chemicals pose respiratory hazards.
  • Walkways and doors must be unobstructed
  • Area must be free from tripping hazards
  • Equipment and chemicals must be stored properly; clutter must be minimized.

Guarding for Safety

All mechanical equipment must be adequately furnished with guards that prevent access to electrical connections or moving parts (such as the belts and pulleys of a vacuum pump). Each laboratory worker must inspect equipment before using it to ensure that the guards are in place and functioning.

Careful design of guards is vital. An ineffective guard can be worse than none at all, because it can give a false sense of security. Emergency shutoff devices may be needed, in addition to electrical and mechanical guarding.

Shielding for Safety

Safety shielding must be used for any operation having the potential for explosion such as

  • whenever a reaction is attempted for the first time (small quantities of reactants must be used to minimize hazards),
  • whenever a familiar reaction is carried out on a larger than usual scale (e.g., 5-10 times more material), and
  • whenever operations are carried out under non-ambient conditions. Shields must be placed so that all personnel in the area are protected from hazard.


Accidents involving glassware are a leading cause of laboratory injuries.

  • Careful handling and storage procedures must be used to avoid damaging glassware. Damaged items must be discarded or repaired.
  • Adequate hand protection must be used when inserting glass tubing into rubber stoppers or corks or when placing rubber tubing on glass hose connections. Tubing must be fire polished or rounded and lubricated, and hands must be held close together to limit movement of glass must fracture occur. The use of plastic or metal connectors must be consid­ered.
  • Glass-blowing operations must not be attempted unless proper annealing facilities are available.
  • Vacuum jacketed glass apparatus must be handled with extreme care to prevent implosions. Equipment such as Dewar flasks must be taped or shielded. Only glassware designed for vacuum work must be used for that purpose.
  • Hand protection must be used when picking up broken glass. (Small pieces must be swept up with a brush into a dustpan.)
  • Proper instruction must be provided in the use of glass equipment designed for specialized tasks, which can represent unusual risks for the first-time user. (For example, separator funnels containing volatile solvents can develop considerable pressure during use.
  • All damaged or broken glass must be disposed of in an approved broken glass container.


Individuals and/or departments purchasing refrigerators for laboratory use are expected to follow university procedures that are in accordance with the latest requirements of NFPA 45 (National Fire Protection Association), “Standard on Fire Protection for Laboratories Using Chemicals and the latest requirements of the Philadelphia Fire Code.

Any quantity of flammable material must be stored in an approved explosion-safe refrigerator. All domestic refrigerators located in a lab or area where hazardous materials are stored must be labeled with a sign stating “Do Not Store Flammables in This Refrigerator.”

Flammability Hazards

Because flammable materials are widely used in laboratory operations, the following rules must be observed:

  • Do not use an open flame to heat a flammable liquid or to carry out a distillation under reduced pressure.
  • Use an open flame only when necessary and extinguish it when it is no longer needed.
  • Before lighting a flame, remove all flammable substances from the immediate area. Check all containers of flammable materials in the area to ensure that they are tightly closed.
  • Notify other occupants of the laboratory in advance of lighting a flame.
  • Store flammable materials properly.
  • When volatile flammable materials are present, use only non-sparking electrical equipment.

Cold Traps and Cryogenic Hazards

The primary hazard of cryogenic materials is their extreme coldness. Cryogenic materials and surfaces as they cool can cause severe burns if allowed to contact the skin. Gloves and a face shield must be worn when preparing or using cold baths. Neither liquid nitrogen nor liquid air is to be used to cool a flammable mixture in the presence of air because oxygen can condense from the air, which leads to an explosion hazard. Appropriate dry gloves must be used when handling dry ice, which must be added slowly to the liquid portion of the cooling bath to avoid foaming over. Workers must avoid lowering their head into a dry ice chest: carbon dioxide is heavier than air, and suffocation can result.

Systems Under Pressure

Reactions must never be carried out in, nor heat applied to, an apparatus that is a closed system unless it is designed and tested to withstand pressure. Pressurized apparatus must have an appropriate relief device. If the reaction cannot be opened directly to the air, an inert gas purge and bubbler system must be used to avoid pressure buildup.

Warning Signs and Labels

All areas must be appropriately labeled with warning signs. Laboratory areas that have special or unusual hazards must be posted with warning signs. Standard signs and symbols have been established for a number of special situations, such as radioactivity hazards, biological hazards, fire hazards, corrosive hazards, toxic hazards and laser operations. Other signs must be posted to show the locations of safety showers, eyewash stations, exits, and fire extinguishers. Extinguishers must be labeled to show the type of fire for which they are intended. All waste containers must be labeled as “Hazardous Waste”

The safety- and hazard-sign systems in the laboratory must enable a person unfamiliar with the usual routine of the laboratory to escape in an emergency (or help combat it, if appropriate).

Emergency telephone Contact numbers (blue sheet) to be called in the event of fire, accident, or hazardous spill are posted prominently in each laboratory by EHRS. The PI full name and 24 hour 7 day week phone number must be posted at the top of the sheet. Campus phone number is unacceptable. In addition, the numbers of the laboratory workers and their supervi­sors must be available.

All containers of chemicals must be properly labeled with chemical contents and contain information on the hazards associated with use of the chemical (refer to SDS sheet when necessary). Abbreviations and chemical formulae are unacceptable. The label should indicate if the chemical is hazardous. Words or ANSI recognized symbols such “caution”, “hazardous”, “toxic”, “dangerous”, “corrosive”, “irritant”, or “carcinogen” are key component in providing hazard information. A label is any written, printed, or graphic material displayed on, or affixed to, containers of chemicals. Labels or other forms of hazard warnings, such as tags or placards, provide immediate warning of potential danger. Unlabeled bottles of chemicals must not be opened; such materials must be disposed of promptly and will require special handling procedures.

Old containers of hazardous chemicals (pre-1985) may not contain hazard warnings. If you are not sure whether a chemical you are using is hazardous, review the SDS or contact your supervisor, instructor or EHRS at 2-2520.

OSHA’s Hazard Communication Standard establishes minimum labeling requirements for most hazardous chemical containers in the workplace. All hazardous chemical containers at the University must be labeled according to these OSHA requirements. Specifically, the container must be labeled with:

  • the contents of the container (i.e., common name of the chemical). Chemical formulas and structural formulas are not acceptable labeling except for small quantities of compounds synthesized in the laboratory;
  • name and address of the manufacturer;
  • physical and health hazards; and
  • recommended protective equipment.

Existing labels on new containers of chemicals or containers in storage shall not be removed or defaced.

Laboratory workers should not work with any chemical from an unlabeled container. Unlabeled bottles of chemicals must not be opened; such materials must be disposed of promptly and will require special handling procedures. However, portable containers intended for immediate use by the employee or student performing the transfer do not need to be labeled. This labeling requirement also does not apply to students assigned unknown chemicals for analysis. In any event, however, hazard information should be provided with all unlabeled chemicals in student laboratories.

Carefully read all information on the label. If you do not understand something, contact EHRS at 2-2520 for an explanation, to request the SDS or assistant.

All containers that hold carcinogens, reproductive hazards or acutely toxic reagents must be properly labeled concerning the health hazard posed by the chemical. Most new reagent containers will have the chemicals hazard clearly displayed on the label. However older reagents and containers of solutions that are mixed in the lab must be properly labeled by the laboratory worker. The laboratory worker may write the hazard class (e.g., carcinogen, etc.) on the container or contact the EHRS at 2-2520 for guidance.

Unattended Operations

Some operations may need to be carried out continuously or over­night. It is essential to plan for interruptions in utility services such as electricity, water, and inert gas. Operations must be designed to be safe, and plans must be made to avoid hazards in case of failure. Wherever possible, arrangements for routine inspection of the operation must be made and, in all cases, the laboratory lights must be left on and an appropriate sign must be placed on the door.

One particular hazard frequently encountered is failure of cooling water supplies. A variety of commercial or homemade devices can be used that (a) automatically regulate water pressure to avoid surges that might rupture the water lines or (b) monitor the water flow so that its failure will automatically turn off electrical connections and water supply valves.

All unattended operations must eb approved by the Superviosor, PI, Department Head or Manager prior to initiation. These unattended operations must be specified in an SOP.

A copy of all unattended SOP’s must be kept on file and available for review upon request. EHRS has developed a Site Specific training sheet to be sued to ensure your compliance with training. This information is to be updated yearly and kept on record win the CHG worksheet

Working Alone

Generally, it is prudent to avoid working in a laboratory or building alone. Under normal working conditions, arrangements must be made between individuals working in separate laboratories outside of working hours to crosscheck periodically. Alternatively, security guards may be asked to check on the laboratory worker. A worker who is alone in a laboratory must not undertake experiments known to be hazardous.

Under unusual conditions, special rules may be necessary. The Supervisor, PI, Department Head or Manager of the laboratory has the responsibility for determining whether the work requires special safety precautions, such as having two persons in the same room during a particular operation.

All operations involving working alone must approved by the Superviosor, PI, Department Head or Manager prior to initiation. These unattended operations must be specified in an SOP

A copy of all working alone SOP’s must be kept on file and available for review upon request. EHRS has developed a Site Specific training sheet to be sued to ensure your compliance with training. This information is to be updated yearly and kept on record win the CHG worksheet

Gas Hose Connectors

As per the National Fuel Gas Code, NFPA, Section 5.5.2, gas hose connectors (ie hoses connecting a gas source to an appliance or equipment such as a Bunsen Burner, provided that all of the following condtions are met:

  • A sut off valve must be installed where the conector is attached.
  • The connector shall not exceed 6 feet
  • The connector shall not be concealed nor shall it pass from room to room or through walls, ceilings or floors,
  • Only listed gas hoses connectors can be used.

Note: This code specifically disallows use of latex tubing as a connector between a gas source and a Bunsen burner.

IX. Emergency Planning

Emergency Planning, Spill Response and Reporting

Any unexpected event or accident situation that occurs during the transport, storage or use of hazardous materials constitutes a potential emergency. The EHRS must be notified immediately when such an event results in contamination of work areas or personnel, or if significant quantities of hazardous materials are released into the environment. Specific emergency procedures must be followed in such circumstances. It may also be required to notify the Temple University Police Department and the University Fire Marshal’s Office depending upon the nature of emergency. Please visit the Emergency Action Plan that is administered by the University Fire Marshall Office.

Each lab or area where hazardous materials are located is required to develop emergency procedures specific to their lab or area. The following items must be completed:

  • Design an emergency egress map
  • Make a list of emergency contact names and post by the phone. The EHRS posts an emergency contact sheet that is required to be posted at each phone. The PI or designee must post their emergency phone number on the sheet.
  • Ensure that an up to date chemical inventory is readily available and has been submitted to EHRS on an annual bases. Inventory needs to be made available to First Responders.
  • Ensure that all lab doors are properly posted.
  • Develop and document lab-specific emergency procedures.

You should anticipate small spills by having the appropriate safety equipment and spill response kit on hand. Each lab or area must have an emergency and spill plan which addresses their specific need. Departments,/Centers/Labs should include items to address individual that may have special needs.

If there is a spill immediately alert personnel in the area. Do what is necessary to protect life. Confine the spill if possible. Call for assistance if the spill is large, a threat to personnel, students or the public, or if it involves radioactive materials, corrosives, highly toxic, or reactive chemicals.

The Supervisor, PI, Department Head or Manager must ensure that all lab personnel are aware of the location and hours of the nearest hospital, Occupational Heath and or Student Health. The name , location and hours of operation must be included in the CHG worksheet.

Do no attempt to personally clean a major spill or a spill of an unknown or extremely hazardous substance. Examples of extremely hazardous substances include bromine, hydrazine, cyanides, Class 1A flammable solvents, alkali metals, and white phosphorus.

Emergency assistance is available 24 hours a day, seven days a week. You may call the EHRS if you need assistance and information regarding management and/or use of hazardous materials. For concerns about security, injuries, fire safety or any other emergency, you should call extension 1-1234 and state the nature of your concern and the specific assistance you seek.

The EHRS is ready to provide emergency assistance any time of the day and any day of the week.

  • Follow the following guidelines to obtain emergency help:
  • During business hours (8:00am to 5:00pm on weekdays), contact EHRS at (215) 707-2520, or call the page operator at (215) 707-4545 and ask the operator to page a representative of EHRS.
  • During other hours and on weekends and holidays, call the page operator at (215) 707 4545 and ask the operator to page a representative of EHRS and if needed, the Fire Marshal’s Office.
  • University Security may also be contacted at 1-1234.


The following procedure should be followed in case of fire:

  • Sound the building fire alarm.
  • Call extension 1-1234 and state the nature of the problem and location
  • If possible, and trained to do so, attempt to put out the fire by approved methods (e.g., fire extinguisher) and only if other fire hazards or radiation hazards are not present
  • Notify all persons present to vacate the area and immediately call the EHRS
  • Once the fire is out, isolate the area to prevent the spread of possible contamination
  • Survey all persons involved in combating the fire for possible contamination
  • Decontaminate personnel by removing contaminated clothing and flushing contaminated skin with lukewarm water, then washing with a mild soap
  • In consultation with the EHRS, determine a plan of decontamination and the types of protective devices and survey equipment that will be necessary to decontaminate the area
  • Allow no one to return to work in the area unless approved by the EHRS
  • Cooperate with the CHO, Fire Marshal’s Office, and/or the EHRS’s staff in the investigation of the root and causes.
  • Follow the instructions of the CHO and/or the EHRS’s staff in the decontamination techniques, surveys and documentation
  • Explosions/Fires, or Major Emergencies
  • Take the following steps in case of fire, explosion or any other such incident in the work area:
  • Sound the building fire alarm.
  • Notify all persons in the area to leave immediately
  • Call extension 1-1234 and state the nature of the problem and location
  • Notify the EHRS
  • Upon arrival of firefighters, inform them where hazardous materials(including radioactive materials) are stored or where radioisotopes were being used; inform them of the present location of the hazardous materials and the best possible entrance route to the hazardous area, as well as any precautions to avoid exposure or risk of creating contamination by use of high pressure water, etc.
  • Cooperate with the EHRS, Fire Marshal’s Office, and campus security in investigating the root cause. Provide bioassay samples if requested; and
  • Allow no one to return to work in the area unless approved by the EHRS
  • Follow the instructions of the EHRS’s staff in the decontamination techniques, surveys and documentation
  • Chemical Spills

Please refer to the Chemical Spill Managment Policy for instructions on how to respond to minor and major chemical spills. Each lab must develop and implement a spill plan

  • Contamination Only

Skin contamination is always a possibility when working with hazardous materials and can result in significant health hazards if not removed.

  • Injury with Personnel Contamination

In the event of a serious injury (heavy bleeding, heart attack, etc.) seek medical assistance immediately. Notify your supervisor and the EHRS.

For a minor injury (e.g., puncture wound, suspected inhalation or ingestion of hazardous material, skin contamination, etc.):

  • Assist person with use of body shower and/or eyewash equipment.
  • Flush body and/or eyes with water for at least 15 minutes
  • Remove contaminated clothing while under body shower.
  • Wash skin with mild soap and water-do not use neutralizing agents, creams, lotions or salve
  • See medical attention.
  • Environmental Release and Oil Spill Notification

Immediately notify EHRS for suspected or known releases to the environment (air, water, land ,drains). EHRS can be contacted during normal business hours at 215-707-2520 or after hours via the Page Operator at 215-707-4545. Campus Police must also be notified at 215-204-1234(1-1234)). Notifications must be made to regulatory agencies immediately after a known, confirmed or suspected release.

  • Preparing Spill Plans
    • Review your chemical inventory to identify hazards of chemicals used and stored in your area.
    • Purchase or assemble a spill kit appropriate for your chemicals. Consider special needs for air and water reactives, poisons, and hydrofluoric acid.
    • Post Emergency Contact Information or call lists at the entrance to the area.
    • Train lab occupants on area spill procedures.
  • Spill Kit Supplies

Supplies are available from lab and safety catalogs.

    • Basic Kit Supplies:
      • Chemical Resistant Container for Kit
      • Universal Absorbents
      • Goggles, Gloves
      • Disposable Coverall or Apron
      • Shoe Covers
      • Dust Pan and Whisk Broom for Solids
      • Hazardous Waste Labels
    • Add as needed in your area:
      • Personal Protective Equipment such as face shields, aprons, boots.
      • General neutralizing agents such as sodium bicarbonate for acids, and citric acid or sodium bisulfate for bases.
      • Agent specific neutralizers available for acids, bases, formaldehyde and solvents.
        Mercury collection sponges.
      • Specialized supplies for air or water reactive chemicals and Hydrofluoric Acid.
      • Only add respirators if additional training and program requirements have been met.
  • Spill Training
  • Spill Training for your area should include:
    • Recognition (sight, smell, alarms, etc.)
    • First aid for chemical injuries that may occur in your area
    • Handling emergencies (notification, action)
    • Prevention/Containment (secondary containment, spill limitation)
    • Clean-up (personal protection, use of equipment, preventing damage, etc.)
    • Packaging and handling of residue
  • How to Minimize Spills
    • Store hazardous liquid containers in a pan or tray big enough to hold the contents if the container breaks or leaks.
    • Buy liquids in plastic coated bottles.
    • Use bottle carriers for protection and containment.
    • Put pans under experiments.
    • Use traps on vacuum lines.
    • Use carts designed to prevent materials from sliding off the cart.
    • Have sink stoppers and drain covers handy to prevent material from entering drains.

Accident Reporting

All accidents or incidents must be reported and properly documented:

The main requirements are:

  • All injuiries must be reported by the injured employee to his/her supevisor
  • The supervisor must complete an incident report. See Department or Area for specific details of what forms need to be compeleted. Please refer to Temple University Human Resources for additional information.

Supervisors and/or departments should investigate the cause or causes of incidents to prevent reoccurrence. Contact EHRS for assistance if needed. Follow-up should be done by the department to ensure that corrective action has been taken.

All incident reports with listed corrective actions must be kept on file with the CHG worksheet and be readily available fore review upon request.

Everyday Hazards

Finally, laboratory workers must remember that injuries can and do occur outside the laboratory or other work area. It is important that safety be practiced in offices, stairways, corridors, and other places. Here, safety is largely a matter of common sense, but a constant safety awareness of everyday hazards is vital.

X. Personal Protective Equipment (PPE) & Safety Equipment

A variety of specialized clothing and equipment is commercially available for use in the laboratory. The proper use of these items will minimize or eliminate exposure to the hazards asso­ciated with many laboratory operations. The primary goal of laboratory safety procedures is the prevention of accidents and emergencies. However, accidents and emergencies may nonetheless occur and, at such times, proper safety equipment and correct emergency procedures can help minimize injuries or damage. Please visit the policy on Personal Protective Equipment

Every laboratory worker must be familiar with the location and proper use of the available personal protective equipment (PPE) and safety equipment and with emergency procedures. Instruction on the proper use of such equipment, emergency procedures, and first aid is available at Temple University to everyone who might need it. All PPE must be clean and in an accessible location. All PPE must be provided at no cost to the employee.

Approved personal protective devices are to be used only when engineering and administrative controls cannot be used or made adequate or while such controls are being instituted. Engineering and administrative controls to reduce or eliminate exposures to hazardous chemicals include:

  • Substitution of a less hazardous substance;
  • Substitution of a less hazardous equipment or process (e.g., safety cans for glass bottles);
  • Isolation of the operator or the process;
  • Local and general ventilation (use of fume hoods);
  • Hazard education; and
  • Job rotation.

SDS lists the personal protective equipment recommended for use with hazardous chemicals. Personal Protective Equipment (such as lab coats, gloves, etc.) must not be worn outside of the laboratory. If you have any questions regarding the selection of appropriate personal protective equipment, call EHRS at 2-2520.

Eye Protection

Eye protection is required for all personnel and any visitors present in locations where chemicals are stored or handled. No one must enter any laboratory without appropriate eye protection. Eye protection used in the laboratory must comply with the Standard for Occupational and Educational Eye and Face Protection established by the American National Standards Institute (ANSI Z87.1a-1991).

Supervisors, PI, Department Heads and Manager must make appropriate eye protection devices available to visitors or others who only occasionally enter eye protection areas. Ordinary prescription glasses do not provide adequate protection from injury to the eyes. Side shields that attach to regular safety spectacles offer some protection from objects that approach from the side but do not provide adequate protection from splashes

Conference rooms, libraries, offices, microscope rooms in which chemicals are not in use, and similar rooms are not normally eye protection areas. However, at any time when chemicals are used in such rooms, even temporarily, signs must be posted and all persons in the vicinity warned that eye protection is temporarily required. For laboratory operations that do not involve the use of chemicals and, if chemicals are not used in the immediate vicinity, it may be permissible by arrangement with the PI, to remove the eye protection.

Additional protection may be required when carrying out more hazardous operations.

Other Eye Protection

It is important that each operation be analyzed to ensure that adequate eye protection is used. When operations that involve potential hazard to the eyes are performed (such as handling unusua­lly corrosive chemicals), more complete eye protection than spectacles must be worn. It is the responsibility of the laboratory custodian to determine the level of eye protection required and to enforce eye protection rules.

Other forms of eye protection that may be required for a particular operation include the following:

  • Goggles: Goggles are not intended for general use. They are intended for wear when there is danger of splashing chemicals or flying particles. For example, goggles must be worn when working with glassware under reduced or elevated pressure and when glass apparatus is used in combustion or other high temperature operations. Impact protection goggles have screened areas on the sides to provide ventilation and reduce fogging of the lens and do not offer full protection against chemi­cal splashes. Goggles that have splash proof sides or face shields must be used if there is the potential for a splash hazard.
  • Face Shields: Goggles offer little protection to the face and neck. Full face shields that protect the face and throat must always be worn when maximum protection from flying particles and harmful liquids is needed; for full protection, safety glasses must be worn with face shields. A face shield or mask may be needed when a vacuum system (which may implode) is used or when a reaction that has a potential for mild explosions is conducted.
  • Specialized Eye Protection: There are specific goggles and masks for protection against laser hazards ultraviolet or other intense light sources, as well as glassblowing goggles and welding masks and goggles. The Principal Investigator must determine whether the task being performed requires specialized eye protection and insist on the use of such equipment if it is necessary.


Skin contact is a potential source of exposure to toxic materials; it is important that the proper steps be taken to prevent such contact.

  • Proper protective gloves (and other protective clothing, when necessary) must be worn whenever the potential for contact with corrosive or toxic materials and materials of unknown toxicity exists.
  • Gloves must be selected on the basis of the material being handled, the particular hazard involv­ed, and their suitability for the operation being conducted.
  • Before each use, gloves must be inspected for discolor­ation, punctures, and tears.
  • Before removal, gloves must be washed appropriately. (NOTE: Some gloves, e.g., leather and polyvinyl alcohol, are water perme­able.)
  • Chemicals eventually permeate glove materials. However, they can be used safely for limited time periods if specific use and glove characteristics (i.e., thickness and permeation rate and time) are known. Some of this information can be obtained from glove manufacturers, or the gloves used can be tested for breakthrough rates and times. Contact EHRS at 2-2520 for addition information.
  • Gloves must be replaced periodically, depending on frequency of use and permeability to the substance(s) handled. Gloves overtly contaminated (if impermeable to water) must be rinsed and then carefully removed.
  • Gloves must be worn whenever it is necessary to handle corrosive materials, rough or sharp-edged objects, very hot or very cold materials, or whenever protection is needed against accidental exposure to chemicals.
  • Gloves must not be worn around moving machinery. Many different types of gloves are commercially available.
  • Leather gloves may be used for handling broken glassware, for inserting glass tubes into rubber stoppers, and for similar operations where protection from chemicals is not needed.
  • Specialized gloves are manufactured for electrical linesmen, welders, and others. It is the responsibility of the laboratory custodian to determine whether specialized hand protection is needed for any operation and to ensure that needed protection is available.
  • Insulated gloves must be used when working at temperature extremes. Various synthetic materials such as Nomex and Kevlar can be used briefly up to lOOO°F. Gloves made with these materials or in combination with other materials such as leather are available.
  • There are various compositions and thickness of latex gloves. Common glove materials include neoprene, polyvinyl chloride, nitrile, and butyl and natural latex. These materials differ in their resistance to various substances. Specific information on this topic is often available from glove manufacturers' catalogs, although such data is usually only qualitative. Examples of resistance to chemicals for gloves is listed below

Resistance to Chemicals of Common Glove Materials

(E = Excellent, G = Good, F = Fair, P = Poor)


Chemical Rubber Neoprene Nitrile Vinyl

Acetaldehyde G G E G

Acetic acid E E E E

Acetone G G G F

Acrylonitrile P G -- F

Ammonium hydroxide (sat) G E E E

Aniline F G E G

Benzaldehyde F F E G

Benzenea P F G F

Benzyl chloridea F P G P

Bromine G G -- G

Butane P E -- P

Butyraldehyde P G -- G

Calcium hypochlorite P G G G

Carbon disulfide P P G F

Carbon tetrachloridea P F G F

Chlorine G G -- G

Chloroacetone F E -- P

Chloroforma P F G P

Chromic acid P F F E

Cyclohexane F E -- P

Dibenzyl ether F G -- P

Dibutyl phthalate F G -- P

Diethanolamine F E -- E

Diethyl ether F G E P

Resistance to Chemicals of Common Glove Materials

(E = Excellent, G = Good, F = Fair, P = Poor)


Chemical Rubber Neoprene Nitrile Vinyl

Dimethyl sulfoxideb

Ethyl acetate F G G F

Ethylene dichloridea P F G P

Ethylene glycol G G E E

Ethylene trichloridea P P -- P

Fluorine G G -- G

Formaldehyde G E E E

Formic acid G E E E

Glycerol G G E E

Hexane P E -- P

Hydrobromic acid (40%) G E -- E

Hydrochloric acid (conc) G G G E

Hydrofluoric acid (30%) G G G E

Hydrogen peroxide G G G E

Iodine G G -- G

Methylamine G G E E

Methyl cellosolve F E -- P

Methyl chloridea P E -- P

Methyl ethyl ketone F G G P

Methylene chloridea F F G F

Monoethanolamine F E -- E

Morpholine F E -- E

Naphthalenea G G E G

Nitric acid (conc) P P P G

Perchloric acid F G F E

Phenol G E -- E

Phosphoric acid G E -- E

Potassium hydroxide (sat) G G G E

Propylene dichloridea P F -- P

Sodium hydroxide G G G E

Sodium hypochlorite G P F G

Sulfuric acid (conc) G G F G

Toluenea P F G F

Trichloroethylenea P F G F

Tricresyl phosphate P F -- F

Triethanolamine F E E E

Trinitrotoluene P E -- P

a) Aromatic and halogenated hydrocarbons will attack all types of natural and synthetic glove materials. If swelling is to occur, the user must change to fresh gloves and allow the swollen gloves to dry and return too normal.

b) No data on the resistance to dimethyl sulfoxide of natural rubber, neoprene, nitrile, or vinyl materials are available; the manufacturer of the substance recommends the use of butyl rubber gloves.

Other Clothing and Footwear

The clothing worn by laboratory workers can be important to their safety. Such personnel must not wear loose (e.g., saris, dangling neckties, and overlarge or ragged laboratory coats), skimpy (e.g., shorts and/or halter tops), or torn clothing and unrestrained long hair. Loose or torn clothing and unrestrained long hair can easily catch fire, dip into chemicals, or become entangled in an apparatus or moving machinery. Skimpy clothing offers little protection to the skin in the event of a chemical splash. High heeled or open toed shoes, sandals, or shoes made of woven material must not be worn in the laboratory. Shorts, cutoffs, and miniskirts are also inappropriate. Long hair and loose clothing should be contained. Jewelry such as rings, bracelets, and watches should not be worn.

Shoes must be worn at all times in buildings where chemicals are stored or used. Perforated shoes, sandals, open-toes shoes or cloth sneakers must not be worn in laboratories or areas where mechanical work is being done.

Protective Apparel

Appropriate protective apparel is advisable for most laboratory work and may be required for some. Such apparel can include laboratory coats and aprons, jump suits, special types of boots, shoe covers, and gauntlets. It must be either washable or disposable in nature. Garments are commercially available that can help protect the laboratory worker against chemical splashes or spills, heat, cold, moisture, and radiation. If the possibility of chemical contamination ex­ists, personal clothing that will be worn home must be covered by protective appar­el.

Protective apparel must resist physical hazards and permit easy execution of manual tasks while being worn. It must also satisfy other strength performance requiremen­ts, chemical and thermal resistance, flexibility, and ease of cleaning. The required degree of performance can be determined on the basis of the substances being handled. The choice of labo­ratory coat versus rubber/plastic apron versus disposable jump suits depends on the degree of protection required and is the responsibility of the Supervisor PI, Department Head or Manager. Lab workers must wear lab coats while in a lab where hazardous chemicals are being handled. Lab coats should not be worn outside of the lab. The Supervisor, PI, Department Head or Manager must provide lab coats and lab coat laundering services at no cost to all employees who work in the lab.

Laboratory coats are intended to prevent contact with dirt and the minor chemical splashes or spills encountered in laboratory‑scale work. The cloth laboratory coat is, however, primarily a protection for clothing and may itself present a hazard (e.g., combustibility) to the wearer; cotton and synthetic materials such as NomexR or TyvekR are satisfactory; rayon and polyesters are not. Laboratory coats do not significantly resist penetration by organic liquids and, if significantly contaminated by them, they must be removed immediately.

Plastic or rubber aprons provide better protection from corrosive or irritating liquids but can complicate injuries in the event of fire. Furthermore, a plastic apron can accumulate a considerable charge of static electricity and must be avoided in areas where flammable solvents or other materials could be ignited by a static discharge. Disposable outer garments (e.g., Tyvek) may, in some cases, be preferable to reusable ones. One such case is that of handling appreciable quantities of known carcinogenic materials, for which long sleeves and the use of gloves are also recommended.

Laboratory workers must know the appropriate techniques for removing protective apparel, especially any that has become contaminated. Chemical spills on leather clothing or accessories (watchbands, shoes, belts, and such) can be especially hazardous because many chemicals can be absorbed in the leather and then held close to the skin for long periods. Such items must be removed promptly and decontaminated or discarded to prevent the possibility of a chemical burn. Specialized or disposable clothing for use with particular classes of hazardous chemicals must be treated in a similar way. Safety showers must be readily accessible for use when a chemical spill contaminates large sections of clothing or skin.

Foot Protection

More extensive foot protection than ordinary shoes may be required in some cases. Rubber boots or plastic shoe covers may be used to avoid possible exposure of the feet to corrosive chemicals or large quantities of solvents and water that might penetrate normal foot gear (e.g., during cleanup operations). Because these types of boots and covers may increase the risk of static spark, their use in normal laboratory operations is not advisable.

Other specialized tasks may require footwear that has, for example, conductive soles, insulated soles, or steel-toed boots. The Supervisor, PI, Department Head and Manager must recommend the use of such protection whenever appropriate.

Respiratory Protection

Departments or laboratories that issue, recommend or provide respirators for employee protection are required to implement a respiratory protection program in accordance with TU Respiratory Protection Program. EHRS must be contacted for assistance in determining the need for implementation of a respirator program. Respirator program components include hazard evaluations, annual medical evaluations, fit-tests and training for individuals using respirators, and written programs, including record keeping and annual reviews.

Safety Equipment

Safety and emergency equipment must be available in all laboratories. The protection afforded by this equipment depends on its proper and consistent use. Laboratory workers must realize that safety devices are intended to help protect them from injury and must not avoid using such devices when they are needed.

All laboratories in which chemicals are used or stored must have available proper PPE, fire extinguishers, spill control kits, as well as laboratory hoods and laboratory sinks (which can be considered part of the safety equipment of the laboratory). It is the responsibility of the Supervisor, PI, Department Head or Manager to ensure that all safety equipment is available and properly maintained.

In addition to these standard items, there may also be a need for other protection. It is the responsibility of the Supervisor, PI, Department Head or Manager to recommend and provide supplementary safety equipment as needed. Please consult the EHRS handbook or contact EHRS at 2-2502 for additional information.

Signage must also be placed within a lab indicating where safety equipment is located.

Emergency Showers and Eyewash Stations

All labs are required to have safety showers and emeregcny eyewashes. It is the responsibility of the Supervisor, PI, Department Head or Manager to ensure that the Emergency eyewashes and showers are operationally tested on a weekly basis and tested annually by Facilities Management. Please visit the Emergency Equipment policy for information on emergency eyewashes and showers.

Flammable Liquid Storage Cabinets

It is recommended that Flammable liquid storage cabinets are to be used at all times. Flammable liquid storage cabinets must meet the following specifications.

  • Cabinets must comply with NFPA and OSHA standards
  • Cabinets must have self-closing door(s) , with red lettering stating “Flammable-Keep Fire Away”.
  • Two doors are required on all cabinets except 10 and 20 gallon sizes where one door is required. Where two doors are required, they may be ither bifolding or hinged on one side.
  • Cabinets must be made of approved metal construction and meet minimum construction requirements.

Fume Hoods and Ventilation

Local exhaust ventilation is one of the best engineering methods available to reduce the health hazard risk associated with the use of hazardous chemicals in the laboratory. Adequate ventilation is defined as ventilation that is sufficient to keep the concentration of a chemical below the PEL or TLV.

Laboratory fume hoods are the most common local exhaust ventilation devices found in the laboratory. Fume hoods are used to prevent hazardous, offensive or flammable gases and vapors from mixing with the general room air. A hood, especially with the sash down, acts as a physical barrier between the laboratory workers and chemical reactions. The hood can also contain accidental spills of hazardous chemicals . Please visit the policy on Laboratory Ventilation Managment Program must be consulted to ensure that you are following all the necessary requirements as they pertain to your lab or area.

To be effective, laboratory fume hoods must be installed, maintained and used correctly. The National Research Council in its publication “Prudent Practices for Handling Hazardous Chemicals in Laboratories” (1981) recommends that the following factors be remembered in the daily use of hoods:

  • Hoods should be considered as backup safety devices that can contain and exhaust toxic, offensive, or flammable materials, when the design of an experiment fails;
  • Hoods should not be used as a means of disposing hazardous chemicals;
  • Hoods should be evaluated before use to ensure adequate face velocities (typically 80-120 LFPM) and the absence of excessive turbulence. Further some continuous monitoring deice for adequate hood performance must be present and must be checked before the hood is used (i.e., swinging vane velometer).
  • Except when adjustments of apparatus within the hood are being made, the hood should be kept closed: vertical sashes down and horizontal sashes closed. Sliding sashes should not be removed from horizontal sliding-sash hoods. The face opening of the hood should be kept small to improve the overall performance of the hood;
  • The airflow pattern, and thus the performance of a hood, depends on such factors as placement of equipment in the hood and room drafts from open doors. For example, the placement of equipment in the hood can have a dramatic effect on its performance.
  • Moving an apparatus 5-10 cm back from the front edge into the hood can reduce the vapor concentration at the user's face by 90%; and

Hoods are not intended primarily for storage of chemicals. Materials stored in them should be kept to a minimum. Whenever practical, hazardous chemicals should be moved from hoods into cabinets for storage. EHRS conducts periodic evaluation of all laboratory fumehoods.

Special Purpose Fume Hoods

Other local ventilation devices such as glove boxes and canopy hoods must be used when needed. Contact EHRS for additional instructions and information.

  • Perchloric Acid Fume Hood

Due to the potential explosion hazard of perchloric acid when combined with organic materials, this hood type must be used for perchloric acid digestion. It must be constructed of relatively inert materials such as type 316 stainless steel, ceramic-coated material, or PVC. Hoods used for these applications must have integral bottoms, covered interiors, and a drain. Wash down features is required since the hood and duct system must be thoroughly rinsed after each use to prevent the accumulation of reactive residue.

The Supervisor, PI, Department Head or Manager must ensure that all fume hoods (new, existing or relocated) have been inspected according to the specified requirements as outlined in the Laboratory Ventilation Management Program.

In addition, a fume hood survey form must be submitted to EHRS on an annual basis whenever a hood is relocated or a new hood is introduced into the lab.

In the event of a ventilation failure or recurring low flow alarm on the monitor, occupants should contact the Facilities Managment. Occupants should place lids on open containers, lower the fume hood sash, and shut down equipment and secure reactions that may be generating hazardous emissions.

XI. Standard Operating Procedures (SOP)

General procedures or SOP’s must be followed for handling all chemicals in addition to specific procedures for chemical hazard groups (toxins, flammables, etc.). Safe work practices are essential to laboratory safety. They must be known, understood and followed by all persons working with potentially hazardous chemicals and equipment. To be most effective, they must be developed and documented as “Standard Operating Procedures” (SOP’s). SOP’s are an integration of the technical requirements to complete laboratory procedures and actions necessary to assure safety.

SOP’s may be described in four categories:

  • Basic Safety Rules
  • General SOP
  • Lab Specific SOP
  • Special Hazard SOP

Basic Safety Rules

Some actions may be described as basic or fundamental to safety in any laboratory or other situation where potential hazards exist (e.g. wearing appropriate eye protection, closing hood sashes when leaving a hood, not smoking or eating in the vicinity of hazardous chemicals, etc.). These simple, somewhat “common sense” rules are important. If basic rules are followed, it is more likely that other, more complex and perhaps less intuitive, safety procedures will also be followed.

Laboratory groups should consider developing their own “Basic Safety Rules” and posting them in the laboratory. Examples of basic safety rules may be found in various sources.

  • Obtain and review Safety Data Sheets (SDS) before ordering and using chemicals. Ensure that the material can be safely procured, stored, used, and disposed of.
  • Know the hazards associated with materials you are using.
  • Be prepared for emergencies and know what action to take. Assure that necessary supplies and equipment are available for handling small spills.
  • Know the location of safety equipment such as emergency shower, eyewash, fire extinguisher, fire alarm, and emergency telephone numbers.
  • Do not work alone in the laboratory if you are working with chemicals.
  • Purchase minimum amounts of hazardous materials necessary to accomplish work and dispense only amounts necessary for immediate use.
  • Use hazardous materials only as directed and for their intended purpose.
  • Never smell or taste a hazardous chemical.
  • Avoid direct contact with any chemical, use protective equipment to avoid exposure, and review SDS for specific recommendations for each chemical used.
  • Smoking, drinking, eating, and the application of cosmetics are forbidden in areas where hazardous materials are in use.
  • Ensure emergency contact information is posted at the lab entrance.
  • Ensure all containers are labeled.
  • Label all secondary containers with chemical name and hazard information.
  • Assure ventilation is adequate for the materials you are using. Where possible, handle all materials in a chemical fume hood.
  • Electrically ground and bond conductive containers using approved methods before transferring or dispensing a flammable liquid from a large container.
  • Store chemicals in compatible categories.
  • Only permit reactions to run unattended when the reaction is well understood, provisions are in place to contain toxic substances in the event of a utility failure, and emergency contact information is posted on the door.
  • Dispose of waste properly according to the Hazardous Waste Guide
  • When transporting chemicals outside the lab, use precautions to avoid dropping or spilling chemicals. Use bottle carriers for glass containers and use carts with edges to prevent containers from falling off the cart and breaking.

General Standard Operating Procedures (SOP)

General SOP’s are those that apply for more than one laboratory or laboratory group. They may include procedures recommended or required on a university-wide basis. They may also include “generic” procedures for using some types of chemicals or laboratory equipment. Sources of information on general SOP’s include reference books, chemical suppliers, equipment manufacturers, training materials (e.g., video tapes available from EHRS).

EHRS recommends the following General SOP’s which apply for the storage, use and disposal of chemicals which may present a physical or health hazards. General SOP's for some categories of chemicals are available for your use.

Anyone working in a laboratory is required to abide by the following general standard operating procedures:

  • Chemical Labels

Carefully read the labels of all hazardous chemicals before they are used. Any in-house dilution made from stock chemical bottles is required to be labeled with the chemical identity, concentration, and primary hazard.

  • Safety Data Sheets

Anyone using chemicals should be aware of the hazardous properties associated with the use of those chemicals. This can be accomplished by reviewing the SDSs. The SDSs for hazardous chemicals should be located internally for the lab in a designated area. SDS may also be obtained from the EHRS library(PAH-Room B-49) or the Temple CEMS SDS Webpage. The location of the SDS should also be included in the site specific CHP SDS location posters should be posted on departmental bulletin boards and in each laboratory in compliance with the Federal Hazard Communication Standard.

  • Personal Protective Equipment (PPE)

Personal protective equipment (PPE) recommended on a chemical's hazard warning label or SDS (e.g., neoprene gloves, vinyl splash aprons, chemical splash goggles, etc.) may be required to be used during handling of the chemicals. Lab requirements for PPE must be specified by the Supervisor, PI, Department Head or Manager, based on evaluation of potential hazards. This section should list the types of PPE available, what it’s used for and where it is stored. Proper cleaning, care and repair instructions should also be included. PPE includes eye, hand , foot and hand protection. If adequate information cannot be obtained from the SDS or other sources, contact EHRS (2-2520) for technical assistance. (See the policy on Personal Protective Equipment for further information.)

  • Containment Devices

Any containment devices recommended on the chemical container labels or SDSs (e.g., chemical fume hood, glove box, explosion proof refrigerator) will be required for the storage and active handling of the chemicals.

  • Chemical Waste

Chemical waste is required to be disposed of in compliance with Federal, State and Local environmental regulations. Chemicals should be in a labeled waste container specific for the class of chemicals. Evaporation in a chemical fume hood is not an option. Waste chemicals, no matter how seemingly innocuous, may not be poured down the drain to the sanitary sewer .

Lab-Specific SOP's

Every laboratory and laboratory group will have some chemicals and/or procedures and equipment which can potentially present specific hazards not addressable by general or "generic SOP's". Supervisors, PI, Department Heads or Managers must determine these situations and develop lab-specific SOP's accordingly. Copies of these SOP’s should be kept with the Site Chemical Hygiene Guide Worksheet.

The following discussion may be helpful in the development of Laboratory-Specific SOP's for handling hazardous chemicals.

  • Consider the chemical process
  • List all possible reactions, including side reactions, before beginning.
  • Think through all reactants, intermediates, and products in terms of flammability, toxicity, and reactivity hazards. Consider the following:
  • Does it decompose, and if so, how rapidly and to what products?
  • What is its stability on exposure to heat, light, water, metals, etc.?
  • Is it impact sensitive?
  • With what substances is this material incompatible? Are any incompatible materials in the vicinity of the reaction?
  • Is it toxic? If so, what type of hazard (inhalation, ingestion, skin contact)? What protective measures are required?
  • What is the recommended first aid treatment in case of an accidental exposure?
  • Follow recognized, safe practices concerning protective equipment, housekeeping, handling hazardous chemicals, and proper use of lab equipment.
  • Determine the quantity and the rate of the evolution of heat and gases that may be released during the reaction. Use the thermodynamic and kinetic data from the reaction chemistry.
  • Question the process dynamics
  • How violent will it be?
  • What is the effect of catalysts or inhibitors?
  • How will air affect the reaction?
  • How are the waste products to be handled and disposed of properly?
  • Develop contingency plans
  • Electric power failure
  • Cooling system failure
  • Exhaust system failure
  • Over pressurization
  • Water leaks into system
  • Air leaks into system
  • A fire occurs due to the reaction (Is the appropriate extinguishing agent nearby?)
  • Reaction container breaks or contents spill
  • During the process
  • Provide adequate cooling, ventilation, pressure relief, and gas purging
  • Isolate the reaction vessel, if possible, and make frequent inspections of equipment during reaction.
  • Post appropriate warning signs near any dangerous equipment
  • Inform others working in the area of the chemicals being used and the possible hazards involved
  • Always stay in the area and monitor systems that may present unusual hazards.
  • Report all accidents and unusual occurrences at once.
  • Some laboratory equipment present special hazards, which will require SOP’s to assure safety. Follow a similar, thorough approach for developing equipment SOP’s.

Particularly Hazardous Substances SOP's

Each Supervisor, PI, Department Head or Manager must identify and prepare a list of those materials and procedures in their lab for which special provisions will be applied. The OSHA Laboratory Standard suggests that these include reproductive toxins, highly (acutely) toxic materials, and "Select Carcinogens".

A list of these lab-specific substances and situations should be placed with the CHG worksheet. Any substance or situation which falls into this category requires the immediate notification to EHRS. In addition, prior approval from the Supervisor, PI, Department Head or Manager is required before any lab personnel can work on any Particularly Hazardous Substances SOP. The OSHA Laboratory Standard indicates that specific consideration should be given to:

  • Establishment of a designated storage and work/use areas
  • Containment devices such as fume hoods or glove boxes
  • Procedures for safe removal of contaminated waste
  • Decontamination procedures

Consideration should be given to the conditions of handling, skin exposure potential, inhalation hazard, use of personal protective equipment, continuous air monitors, alarms, the need for contamination control devices such as glove boxes, decontamination procedure, and the handling of waste materials. All special provisions should be reviewed and discussed by several individuals prior to implementation.

The OSHA Laboratory Standard has mandated that a special review be conducted in any laboratory in which a "particularly hazardous substance" is being used in order to determine if the hazard potential warrants implementation of special controls or procedures to control employee exposure. There is some flexibility in determining whether a particular chemical falls into the category of a Particularly Hazardous Substance chemical. The following types of chemicals should be considered for special controls or procedures:

  • Any chemical designated as highly toxic by oral, dermal or inhalation routes of exposure as defined in the OSHA Hazard Communication Standard.
  • Any chemical designated as one of the following:
    • OSHA regulated carcinogen
    • Listed by National Toxicology Program (NTP) as "Known To Be Carcinogenic"
    • Listed by NTP "Reasonably Anticipated To Be Carcinogenic"
    • Listed as Group 1 carcinogen by International Agency for Research on Cancer (IARC)
    • Listed as 2A or 2B carcinogen by IARC
    • Any chemical designated as "Known To Cause Reproductive Toxicity" according to the Safe Drinking Water and Toxic Enforcement Act of 1986.
    • Other chemicals which have been shown through laboratory experience to present significant or special hazards during laboratory processing activities.
  • For mixtures, the special evaluation requirement may be waived in those instances where the mixture contains less than 1 percent by weight of highly toxic chemicals and less than 0.1 percent by weight of suspect Carcinogens and Reproductive hazards, where there is no information indicating that the mixture would pose the risk of the individual substance.

The Supervisor, PI, Department Head or Manager is responsible for identifying chemicals which meet the criteria of a special hazard material. When special hazard chemicals have been identified, the Supervisor, PI, Department Head or Manager is responsible for developing and implementing laboratory procedures, practices and equipment which are known to be effective or can be shown to be effective to eliminate the special hazard. These procedures and practices could include, but are not limited to, the following: designated areas, containment devices such as fume hoods and glove boxes, procedures for safe removal of materials, decontamination procedures, or pre-approval required specialized operating procedures.

XII. Procedures for Ordering, Procurement, and Receiving of Chemicals

The achievement of safe handling, use, and disposal of hazardous substances begins with the Supervisor, Principal Investigators, Department Heads ,Managers or individuals that requisite such substances for purchase. These individuals must be aware of the potential hazards of the substances being ordered, know whether or not adequate facilities and trained personnel are available to handle such substances, and must ensure that a safe disposal route exists.

Before a new substance that is known or suspected to be hazardous is received, information concerning its proper handling methods, including proper disposal procedures, must be given to those who will be involved with it. It is the responsibility of the Supervisor, Principal Investigators, Department heads or Managers to ensure that the facilities are adequate and that those who will handle any material have received proper training and education to do so safely.

Safety Data Sheets (SDS) provide physical property data and toxicological information. This information can be obtained from the EHRS department. The U.S. Department of Transportation (DOT) requires that shippers furnish and attach department‑­prescribed labels on all shipments of hazardous substances. Anyone who ships or receives hazardous materials must have appropriate training. Contact EHRS for details. These labels indicate the nature of the hazard of the substance shipped and thus provide some indication to the recipient of the type of hazard received, but must not be relied on after the container has been opened.

It is imperative that the Supervisor, Principal Investigators, Department heads ,Managers order small quantities of solvents and chemicals. It is understood that obtaining materials from suppliers in large quantities provides a substantial discount in cost. However, it is more expensive to dispose of chemicals than to buy them. Chemicals purchased must be used within one month of arrival.

The Shipping and receiving of hazardous materials is heavily regulated. Please visit the Shipping of Dangerous Goods/Hazardous Materials for additional information. Comprehensive training requirements apply to all who ship or receive a hazardous materials.

Some high hazard or regulated materials may require notification prior to purchasing. Regulated materials consist of explosives, controlled substances (drugs), toxics, radioisotopes, etiologic agents, select agents and carcinogens. Prior approval and specific instruction are required when working with regulated materials. Contact EHRS at 215-707-2520 for additional information.

XIII. Procedures for Storing Chemicals in Storage Areas

There is a range of possibilities for storing chemical substances. The arrangements made will depend on the size of the organization, the quantities handled, and the nature of the problems. Often, the provision of adequate storage space is given little consideration in the design of laboratory buildings. Lack of sufficient storage space can create hazards due to overcrowding, storage of incompatible chemicals together, and poor housekeeping. Adequate, properly designed and ventilated storage facilities must be provided to ensure personnel safety and property protection.

In many instances, chemicals are delivered directly to the individual who initiated the order. If the facilities of the laboratory are appropriate for the kinds and quantities of materials used, this system may be satisfactory. However, experience has shown that it is sometimes necessary to maintain a reserve of supplies in excess of the amounts that can be kept safely in the laboratory. If the quantities are large or the volumes of the individual containers are such that repackaging is necessary, then a safe place is needed to store these containers and to perform these functions. Depending on needs, this could be a stock room for the laboratory. Stored chemicals must be examined at periodic intervals (at least quarterly). At this time, those that have been kept beyond their appropriate shelf life or have deteriorated, have questionable labels, are leaking, have corroded caps, or have developed any other problem must be disposed of in a safe manner. A first‑in, first‑out system of stock keeping must be used. Shelved chemicals can walk, creep, and even tip over. Such chemicals can be prevented from falling off by placing retaining shock cords or similar restraining devices across the open face of the shelf or by raising the forward face of the shelf about one‑quarter inch.

Stockroom Design

Stockrooms must be usually within or close to the areas served. Stockrooms must not be used as preparation areas because of the possibility that an accident will occur and thereby unnecessarily contaminate a large quantity of materials. Preparation and repackaging must be performed in a separate area.

Stockrooms must be conveniently located and open during normal working hours so that laboratory workers need not store excessive quantities of chemicals in their laboratories. However, this does not imply that all laboratory workers must have unlimited access to the chemicals in the stockroom. Procedures must be established for the operation of any stockroom that place responsibility for its safety and inventory control in the hands of one person. At Temple University, this individual is the Supervisor, Principal Investigators, Department heads or Managers of the stockroom, who must be readily available.

Stockrooms must be well ventilated. If storage of opened containers is permitted, extra local exhaust ventilation and the use of outside storage containers or spill trays are necessary.

Flammable Liquids

At Temple University, the storage of bulk quantities of flammable materials is discouraged. However, if needed, centralized storage of bulk quantities of flammable liquids provides the best method of controlling the associated fire hazard.

Because the most effective way to minimize the impact of a hazard is to isolate it, storage and dispensing room for flammable liquids is best located in a special building separated from the main building. If this is not reasonable, and the room must be located in a main building, the preferred location is a cutoff area on the at‑grade level and having at least one exterior wall. Cutoff is a fire‑protection term defined as "separated from other areas by fire‑rated construction." In any case, storage rooms for flammable liquids must not be placed on the roof, located on a below‑grade level, an upper floor, or in the center of the building. All of these locations are undesirable because they are less accessible for fire fighting and potentially dangerous to the safety of the personnel in the building.

The walls, ceilings, and floors of an inside storage room for flammable liquids must be constructed of materials having at least a 2‑hour fire resistance, and there must be self‑closing Class B fire doors. All storage rooms must have adequate mechanical ventilation controlled by a switch outside the door and explosion‑proof lighting and switches. Other potential sources of ignition, such as burning tobacco and lighted matches, must be forbidden.

Drum Storage

Occasionally, 55 gallon drums are used to ship flammable liquids but are not intended as long‑time inside storage containers. It is not safe to dispense from sealed drums exactly as they are received. The bung must be removed and replaced by an approved pressure and vacuum relief vent to protect against internal pressure buildup in the event of fire or if the drum might be exposed to direct sunlight.

If possible, drums must be stored on metal racks placed such that the end bung openings are toward an aisle and the side bung openings are on top. The drums, as well as the racks, must be grounded with a minimum length of American wire gage 10 wire. Because effective grounding requires metal‑to‑metal contact, all dirt, paint, and corrosion must be removed from the contact areas. Spring‑type battery clamps and a minimally sized conductor (e.g., American wire gage 8 or 10) are satisfactory. It is also necessary to provide bonding to metal receiving containers to prevent accumulation of static electricity (which will discharge to the ground, creating a spark that could ignite the flammable vapors). Drip pans that have flame arresters must be installed or placed under faucets.

Dispensing from drums is usually done by one of two methods. The first is gravity based through drum faucets that are self‑closing and require constant hand pressure for operation. Faucets of plastic construc­tion are not generally acceptable due to chemical action on the plastic materials. The second, and safer, method is to use an approved hand‑operated rotary transfer pump. Such pumps have metering options and permit immediate cutoff control to prevent overflow and spillage, can be reversed to siphon off excess liquid in case of overfilling, and can be equipped with drip returns so that any excess liquid can be returned to the drum.

Regulated Materials

Regulated materials consist of explosives, controlled substances (drugs), toxics, radioisotopes, etiologic agents, select agents and carcinogens. All regulated materials must be segregated from other substances and stored in a well‑defined or identified area that is cool, well ventilated, and away from light, heat, acids, oxidizing agents, moisture, and such. All regulated materials must be stored in a secure location.

The storage of unopened containers of regulated materials normally presents no unusual requirements. However, because containers occasionally develop leaks or are broken, storage rooms must be equipped with exhaust hoods or equivalent local ventilation devices in which containers of toxic substances can be handled.

Opened containers of regulated materials must not be returned to the storeroom.

Prior approval and specific instruction are required when working with regulated materials. Contact EHRS at 215-707-2520 for additional information.

Water-Sensitive Chemcials

Some chemicals react with water to evolve heat and flammable or explosive gases. For example, potassium and sodium metals and many metal hydrides react on contact with water to produce hydrogen, and these reactions evolve sufficient heat to ignite the hydrogen with explosive violence. Certain polymerization catalysts, such as aluminum alkyls, react and burn violently on contact with water.

Storage facilities for water‑sensitive chemicals must be constructed to prevent their accidental contact with water. This is best accomplished by eliminating all sources of water in the storage area; for example, areas where large quantities of water‑sensitive chemicals are stored must not have automatic sprinkler systems. Storage facilities for such chemicals must be of fire‑resista­nt construction, and other combustible materials must not be stored in the same area.

Compressed Gases

Cylinders of compressed gases must be stored in well‑ventilated, dry areas. Where practicable, storage rooms must be of fire‑resistant construction and above ground. Cylinders may be stored out of doors, but some protection must be provided to prevent corrosion of the cylinder bottom and air circulation must not be restricted.

Compressed gas cylinders must not be stored near sources of ignition nor where they might be exposed to corrosive chemicals or vapors. They must not be stored where heavy objects might strike or fall on them, such as near elevators, service corridors, and unprotected platform edges. The cylinder storage area must be posted with the names of the gases stored. Where gases of different types are stored at the same location, the cylinders must be grouped by type of gas (e.g., flammable, toxic, or corrosive). If possible, howev­er, flammable gases must be stored separately from other gases and provision must be made to protect them from fire. Full and empty cylinders must be stored in separate portions of the storage area, and the layout must be arranged so that older stock can be used first with minimum handling of other cylinders.

Cylinders and valves are usually equipped with various safety devices, including a fusible metal plug that melts at 70‑95ºC. Although most cylinders are designed for safe use up to a temperature of 50ºC, they must not be placed where they can become overheated (e.g., near radiators, steam pipes, or boilers). Cylinder caps to protect the container withdrawal valve must be in place at all times during storage and movement to and from storage. Cylinders must be stored in an upright position where they are unlikely to be knocked over, or they must be secured in an upright or horizontal position. Acetylene cylinders must always be stored valve end up to minimize the possibility of discharge. Oxygen must be stored in an area that is at least 20 ft away from any flammable or combustible materi­als (especially oil and grease) or separated from them by a noncombustible barrier at least 5 ft high and having a fire resistance rating of at least 1/2 hour.

Cylinders are sometimes painted by the vendor to aid in the recognition of their contents and make separation of them during handling easier. However, this color coding is not a reliable method for identification of their contents; the stenciled or printed name on the cylinder is the only accepted method. The cylinders that contain compressed gases are primarily shipping containers and must not be subjected to rough handling or abuse. Such misuse can seriously weaken the cylinder and render it unfit for further use or transform it into a rocket having sufficient thrust to drive it through masonry walls. To protect the valve during transportation, the cover cap must be left screwed on hand tight until the cylinder is in place and ready for actual use. Cylinders must never be rolled or dragged. The preferred transport, even for short distances, is by suitable hand truck with the cylinder strapped in place. Only one cylinder must be handled at a time.

A method for detecting the unintentional release of a gas from a compressed gas cylinder may need to be implemented. This may apply in an area where highly hazardous chemicals are stored in where there is the potential for a cylinder to deplete the oxygen content in an area. Please contact EHRS for additional information.

XIV. Transportation of Chemicals

The transportation of hazardous chemicals in laboratory buildings provides the greatest potential for chemical exposure to the building occupants. Spills occurring outside storerooms and laboratories may lead to hazardous concentrations of vapors and gases being distributed throughout the building.

In order to protect against the hazards associated with transportation, all chemicals must be properly packaged in an approved container prior to transporting them. All hazardous chemicals must have secondary containment and be transported using an approved cart or bucket (ex. acid bucket). Carts used for hazardous chemical transport must have sides, on each shelf, that are high enough to retain the containers. Cart wheels must be large enough to prevent the carts from being caught in floor cracks and door and elevator thresholds.

Freight elevators shall be used where available to transport hazardous materials. Hazardous chemicals, substances and research materials must be clearly labeled with the correct chemical name when transported. Hand-written labels areacceptable so long as they are plainly legible. Chemical formulas and structural formulas are not acceptable (except for small quantities of compounds synthesized in the laboratory). Personnel transporting hazardous chemicals must have with them the appropriate gloves and safety glasses or goggles. In addition, they must carry with them appropriate chemical spill control materials during transportation. Questions concerning the transportation of hazardous chemicals should be addressed to the EHRS at 2-2520.

The transportation of chemicals between buildings, campuses or on public streets requires prior approval from EHRS. Contact EHRS at 2-2520 for additional information.

XV. Procedures for Storing Chemcials in Laboratories

General Considerations

Every chemical in the laboratory must have a definite storage place and must be returned to that location after each use. Please review SDS or SOP’s or consult with EHRS at 2-2520 for instructions on the use handling and storage of specific chemicals.

The quantities and volume of material stored in a lab must be kept to a minimum. Numerous regulatory agencies are responsible for regulating the exact volume and quantities of material allowed in one are. The Fire Marshal must be consulted in regards to limitations required for chemical storage.

The storage of chemicals on bench tops is undesirable; in such locations, they are unprotected from potential exposure to fire and are also more readily knocked over. Storage in hoods is also inadvisable because this practice interferes with the air flow in the hood, clutters up the working space, and increases the amount of materials that could become involved in a hood fire. All chemicals must not be stored on the floor.

Prior approval and specific instruction are required when working with regulated materials. Contact EHRS at 215-707-2520 for additional information. Regulated materials consist of explosives, controlled substances (drugs), toxics, radioisotopes, etiologic agents, select agents and carcinogens.

Storage trays or secondary containers should be used to minimize the distribution of material should a container break or leak. Chemicals must be stored in approved storage cabinets (ex. Corrosives cabinets). All incompatible chemicals must be physically separated.

Care must be taken to avoid exposure of chemicals to heat or direct sunlight and to observe precautions regarding the proximity of incompatible substances. Approved laboratory refrigerators are to be used for the storage of chemicals only; food must not be placed in them. All containers placed in the refrigerator must be properly labeled (identification of contents and owner, date of acquisition or preparation, and nature of any potential hazard) and, if necessary, must be sealed to prevent escape of any corrosive vapors. Household grade refrigerators in labs should be labeled: "No food or flammable liquid storage". Flammable liquids must not be stored in laboratory refrigerators unless the unit is an approved, explosion‑proof, fire proof or laboratory‑safe type (NFPA Standards 45 and 56D).

The chemicals stored in the laboratory must be inventoried at least annually, and unneeded items must be given to EHRS for recycling or disposal. All chemical containers (including beakers and flasks) must be labeled with contents and hazard information. Abbreviations and chemicals formula are unacceptable. All chemical containers that have legible labels and chemicals that appear to have deteriorated must be disposed of through EHRS. Funnels must not be left in containers. All water reactive chemicals must be stored away from water and water vapor.

The Principal Investigator (PI) or chemical owner is required to ensure that all their chemicals in their labs are examined annually for replacement, deterioration, expiration, container integrity and overall condition of the chemical. This annual evaluation must be documented. The best method of documentation is utilizing the evaluation function in CEMS. Other acceptable documentation methods include writing the evaluation date on the chemical bottle itself or creating a log book or spreadsheet that list the every chemical present and the respective evaluation date.

On termination, transfer, graduation, or such of any laboratory, the PI must submit Certificate of Vacancy (EHRS Handbook 1.5) to EHRS.

Use common sense in planning chemical storage areas. Carefully read the label before storing a hazardous chemical. The SDS will also provide any special storage information and incompatibilities. Do not store unsegregated chemicals in alphabetical order or incompatible chemicals in close proximity to each other. The amount of space that can be placed between different chemical classes depends on the amount of storage area available in the laboratories. Do not segregate chemical classes into separate rooms unless they will only be used in that room. Segregation that disrupts normal workflow or requires more frequent transport of hazardous chemicals between labs will increase the probability of a chemical spill.

Store dry reagents, liquid reagents and solutions and compressed gases in separate areas. Within each of these chemical forms, segregate the chemicals into hazard classes. Segregate dry reagents as follows:

  • Oxidizing solids;
  • Flammable solids;
  • Water reactive solids; and
  • All others solids.

Segregate liquid reagents and solutions as follows:

  • Acid liquids;
  • Caustic liquids;
  • Oxidizing liquids;
  • Perchloric acid solutions;
  • Flammable or combustible liquids; and
  • All other liquids.

Segregate compressed gases as follows:

  • Toxic gases;
  • Flammable gases; and
  • Oxidizing and inert gases.

Incompatibilities amongst the above mentioned hazards class can exist. Consult SDS for exceptions to the above mention hazard classes. Please review the table below for additional guidelines on chemical compatibility


Chemical Group

Do Not Store With Group #’s


Inorganic acids

2-8, 10,11,13,14,16-19, 21-23


Organic acids

1,3,4,7,14, 16-19,22



1,2,5,7,8,13-18, 20,22,23


Amines and alkanolamines

1,2,5,7,8, 13-18,23


Halogenated compounds



Alcohols, glycols, glycol ethers









Saturated Hydrocarbons



Aromatic hydrocarbons






Petroleum Oils






Monomers, polmerizable esters






Alkylene oxides

1-4, 16,23






3, 6-15,19,21,22



1-2,7,8,13-17, 20,23



3, 6-15,19,21,22





Elemental Phosphours



Acid anhydrides

1,3,4,6,7,14, 16-19

Once separated into hazard classes, the compatible chemicals may be stored alphabetically. Incompatibilities amongst segregated chemical can exist. For example, Nitric acid must be stored separately away from all acids. Use approved storage containers and safety cans for flammable liquids. Use spill trays under containers of strong corrosive reagents. Do not store liquids above eye level. Dispose of old chemicals promptly. Ensure that all containers are properly labeled. All hazardous chemicals received must be labeled with the date received, the date of initial opening and, when available, expiration date. For more information on hazardous chemical storage, contact EHRS at 2-2520.

Flammable and Combustible Liquids

The storage of flammable and combustible liquids in a laboratory must be kept to the minimum amount needed for research and operations. Flammable-liquids storage cabinets are not intended for the storage of highly toxic materials, acids, bases, compressed gases or pyrolytic chemicals. All chemical storage cabinets must be compatible with the chemical stored within it. Storage of flammable liquids outside of a storage cabinet should be avoided when possible. Flammable liquids that are not in use should be stored in an appropriate cabinet. Flammable liquids should not be stored in a refrigerator unless the refrigerator is UL approved for flammable liquid storage. Storage of flammable liquids in household grade refrigerators is a fire hazard.

OSHA regulations for the laboratory storage of flammable and combustible liquids are not based on fire prevention and protection principles but rather address the types and sizes of containers allowable.

Whenever feasible, quantities of flammable liquids greater than 1 liter must be stored in metal containers. Portable approved safety cans are one of the safest methods of storing flammable liquids. These cans are available in a variety of sizes and materials. They have spring‑loaded spout covers that can open to relieve internal pressure when subjected to a fire and will prevent leakage if tipped over. Some are equipped with a flame arrester in the spout that will prevent flame propagation into the can. If possible, flammable liquids received in large containers must be repackaged into safety cans for distribution to laborato­ries. Such cans must be properly labeled to identify their contents.

The storage of flammable materials in wooden cabinets in existing laboratories is prohibited. Other considerations in the storage of flammable liquids in the laboratory include ensuring that aisles and exits are not blocked in the event of fire; that accidental contact with strong oxidizing agents such as chromic acid, permanganates, chlorates, perchlorates, and peroxides is not possible; and that sources of ignition are excluded.

Regulated Materials

Regulated materials consist of explosives, controlled substances (drugs), toxics, radioisotopes, etiologic agents, select agents and carcinogens. Regulated materials must be stored in ventilated storage areas in unbreakable chemically resistant secondary containers. Access to regulated materials must be secured and controlled. Select chemical agents require additional security measures.

Storage areas for regulated materials must exhibit a sign warning of the hazard, have limited access, and are adequately ventilated. Adequate ventilation is of particular concern for hazardous materials that have a high vapor pressure (such as bromine, mercury, etc.). Prior approval and specific instruction are required when working with regulated materials. Contact EHRS at 215-707-2520 for additional information.

Compressed Gases

Carefully read the label before using or storing compressed gas. The SDS will provide any special hazard information. Always use the minimum size cylinder required to perform the work. Cylinders of compressed gases must be handled as high-energy sources. When storing or moving a cylinder, have the cap securely in place to protect the stem. Use suitable racks, straps, chains or stands to support cylinders. Care must be taken to keep them away from sources of heat or ignition. Compressed gas cylinders pose a crush hazard to hands and feet. Do not expose cylinders to temperature extremes. Do not store cylinders or lecture bottles with the regulator in place. If the regulator fails, the entire contents of the gas cylinder may be discharged. Always use the correct regulator. Do not use a regulator adapter. Oil or grease on the high-pressure side of an oxygen cylinder can cause an explosion. Do not lubricate an oxygen regulator. Empty cylinder must be labeled as such.

Cylinders of toxic, flammable or reactive gases should be stored and used in a fume hood or with local ventilation. Never bleed a cylinder completely empty. Cylinder must be stored according to their proper hazard class. Always leave slight pressure to keep contaminants out. Always wear safety glasses when handling compressed gases.

A method for detecting an unintentional release of a gas from a compressed gas cylinder may need be implemented. This may apply in an area where highly hazardous chemicals are present or in an area where there is the potential (large volume of cylinders, gas generators, etc..) for a cylinder to deplete the oxygen content in an area. Please contact EHRS for additional information.

XVI. Potentially Explosive Chemicals and Reagent Combinations

Shock chemicals become increasingly shock sensitive with age. The term “shock sensitive” refers to the susceptibility of the chemical to rapidly decompose or explode when struck, vibrated or otherwise agitated. Consequently, you should write the dates received and date opened on all containers of shock sensitive chemicals. Unless the manufacturer added an inhibitor, closed containers of shock sensitive materials should be discarded after 1 year. Open containers of shock sensitive materials should be discarded within 6 months of opening. The label and the SDS will indicate if a chemical is shock sensitive. Wear appropriate personal protective equipment when handling shock sensitive chemicals. The chemicals listed below are some common classes of laboratory chemicals that have potential for producing a violent explosion when subjected to shock or friction. These chemicals must never be disposed of as such but must be handled by appropriate procedures.

Shock Sensitive Compounds

Acetylenic compounds, especially polyacetylenes, haloacetylenes, and heavy metal salts of acetylenes (copper, silver, and mercury salts are particularly sensitive)

Acyl nitrates

Alkyl nitrates, particularly polyol nitrates such as nitrocellulose and nitroglycerin

Alkyl and acyl nitrites

Alkyl perchlorates

Amminemetal oxosalts: metal compounds with coordinated ammonia, hydrazine, or similar nitrogenous donors and ionic perchlorate, nitrate, permanganate, or other oxidizing group

Azides, including metal, nonmetal, and organic azides

Chlorite salts of metals, such as AgClO2 and Hg(ClO2)2

Diazo compounds such as CH2N2

Diazonium salts, when dry

Fulimanates (silver fulminate, AgCNO, can form in the reaction mixture from the Tollens test for aldehydes if it is allowed to stand for some time; this can be prevented by adding dilute nitric acid to the test mixture as soon as the test has been completed.

Hydrogen peroxide becomes increasingly treacherous as the concentration rises above 30%, forming explosive mixtures with organic materials and decomposing violently in the presence of transition metals.

N-Halogen compounds such as difluoroamino compounds and halogen azides

N-Nitro compounds such as N-nitromethylamine, nitrourea, nitroguanidine, and nitric amide

Oxo salts of nitrogenous bases: perchlorates, dichromates, nitrates, iodates, chlorites, chlorates, and permanganates of ammonia, amines, hydroxylamne, guanidine, etc.

Perchlorate salts. Most metal, nonmetal, and amine perchlorates can be detonated and may undergo violent reaction in contact with combustible materials

Peroxides and hydroperoxides, organic

Peroxides (solid) that crystallize from or are left from evaporation of peroxidizable solvents

Peroxides, transition-metal salts

Picrates, especially salts of transition and heavy metals, such as Ni, Pb, Hg, Cu, and Zn; picric

acid is explosive but is less sensitive to shock or friction than its metal salts and is relatively as a

water-wet paste

Polynitroalkyl compounds such as tetranitromethane and dinitroacetonitrile

Polynitroaromatic compounds, especially polynitro hydrocarbons, phenols, and amines

The chemicals listed below are a few illustrative combinations of common laboratory reagents that can produce explosions when they are brought together or that give reaction products that can explode without any apparent external initiating action. This list is by no means exhaustive; additional information of potentially explosive reagent combinations can be found in publications of the National Fire Protection Association.

Potentially Explosive Combinations of Some Common Reagents

Acetone + chloroform in the presence of base

Acetylene + copper, silver, mercury, or their salts

Ammonia (including aqueous solutions) Cl2, Br2, or I2

Carbon disulfine + sodium azide

Chlorine + an alcohol

Chloroform or carbon tetrachloride + powdered Al or Mg

Decolorizing carbon + an oxidizing agent

Diethyl ether + chlorine (including a chlorine atmosphere)

Dimethyl sulfoxide + an acyl halide, SOCl2, or POCl3

Dimethyl sulfoxide + CrO3

Ethanol + calcium hypochlorite

Ethanol + silver nitrate

Nitric acid + acetic anhydride or acetic acid

Picric acid + a heavy-metal, such as a Pb, Hg, or Ag

Silver oxide + ammonia + ethanol

Sodium + a chlorinated hydrocarbon

Sodium hypochlorite + an amine

Sodium Azide

Sodium azide, a bactericide widely used in medical research, represents a risk due to the possible formation of explosive azides with copper, lead and other heavy metals. Several explosions have been documented where sodium azide solutions had been used in laboratory equipment or discarded in waste water piping systems. These explosions usually occurred when service personnel applied heat or friction to azide contaminated; metallic surfaces.

Heavy metal azides are highly explosive and are formed whenever sodium azide is allowed to react with metals such as lead or copper. The formation of metallic azides in sewer systems is thought to result when water combines with azide leading to the formation of hydrazoic acid (HN3). Hydrazoic acid, itself an explosive, is then able to react with lead or copper to form highly explosive metallic azides.

To prevent azide formation, the following actions must be considered:

  • Substitution - Several commercial antibacterial products are available which do not use sodium azide (Clear-Bath, Roccal, etc.).
  • Flushing of Drains - Always flush drains or metallic equipment thoroughly after discarding sodium azide solutions. This may not eliminate the formation of azide compounds, but will reduce their amount.
  • Storage - Sodium azide solutions must not be stored in cabinets or refrigerators with exposed copper or lead parts.
  • Decontamination - Decontamination must be performed prior to repair or discard of all sodium azide contaminated metallic components or equipment. The decontamination process is as follows:
  • Make a dilute (2-10%) solution of NaOH
  • Pour the NaOH solution into the drain or equipment so as to flush all contaminated surfaces.
  • Treated materials must remain undisturbed for at least 16 hours.
  • Repeat two more times at intervals of one week.
  • Labeling - All drain lines or metallic equipment that are regularly exposed to sodium azide solutions must be labeled indicating the existence of potential explosion hazard. Labels are available from EHRS.

XVII. Water-Reactive and Pyrophoric Chemicals

The following list contains some common laboratory chemicals that react violently with water and that must always be stored and handled so that they do not come into contact with liquid water or water vapor.

Alkali metals

Alkali metal hydrides

Alkali metal amides

Metal alkyls, such as lithium alkyls and aluminum alkyls

Grignard reagents

Halides of nonmetals, such as BCl3, BF3, PCl3, PCl5, SiCl4, S2Cl2

Inorganic acid halides, such as POCl3, SOCl2, SO2Cl2

Anhydrous metal halides, such as AlCl3, TiCl4, ZrCl4, SnCl4

Phosphorus pentoxide

Calcium carbide

Organic acid halides and anhydrides of low molecular weight

Pyrophoric Chemicals

Many members of the following readily oxidized classes of common laboratory chemicals ignite spontaneously in air. Pyrophoric chemicals must be stored in tightly closed containers under an inert atmosphere (or, for some, an inert liquid), and all transfers and manipulations of them must be carried out under an inert atmosphere or liquid.

Grignard reagents, RMgX

Metal alkyls and aryls, such as RLi, RNa, R3Al, R2Zn

Metal carbonyls, such as Ni(CO)4, Fe(CO)5, Co2(CO)8

Alkali metals such as Na, K

Metal powders, such as Al, Co, Fe, Mg, Mn, Pd, Pt, Ti, Sn, Zn, Zr

Metal hydrides, such as NaH, LiAlH4

Nonmetal hydrides, such as B2H6 and other boranes, PH3, AsH3

Nonmetal alkyls, such as R3B, R3P, R3As

Phosphorus (white)

XVIII. Peroxide-Forming Chemicals

Peroxides are a class of chemical compounds with unusual stability problems and are one of the most hazardous classes of chemicals routinely handled in the laboratory.

Peroxides can be inadvertently formed during storage or can be intentional formed during chemical reactions. Some compounds form explosive compounds and others are polymerizable unsaturated compounds that can initiate a runaway, explosive polymerization reaction. The risk increases if the peroxide becomes concentrated by evaporation or distillation.

Peroxide formation is accelerated by exposure to air, light, heat, moisture and contamination from metals.  Peroxides can form in containers that have not been opened.  Peroxide forming-chemicals can be divided into four hazard groups based on the method of reaction.  Refer to the Common Peroxide Forming Chemicals list for common peroxide forming chemicals.

NOTE: Peroxide crystals may form on the container plug or threads of the lid and detonate when the lid is twisted. Do not open a liquid organic peroxide or peroxide-forming chemical if crystals or a precipitate are present

Due to the unstable nature of organic peroxides, it is necessary to contact the Environmental Health & Radiation Safety (EHRS) at 215-707-2520 prior to discarding these chemicals.


A list of common Peroxide Forming Chemicals can be found here.

Purchasing Considerations

  • Eliminate or substitute non-peroxide forming chemicals whenever possible.
  • Purchase minimum quantities of peroxide-forming chemicals. Only purchase the amount that you would expect to use within maximum storage periods as defined in Table 1- Maximum Storage periods for Peroxide Formers (see section on Storage).
  • If possible, purchase peroxide forming chemicals that have a peroxide inhibitor ( ex. Butylated hydroxytoluene (BHT))  added by the manufacturer

Inventory of Peroxide Formers

  • All peroxide formers must be immediately inventoried and entered into the Chemical Environmental Management System (CEMS).
    • All peroxide formers must be documented in CEMS on the date received ( Date Acquired field).
    • All peroxide formers must be evaluated in the time frames specified according to their group and/or SDS. This evaluation date must be documented in CEMS in the Last Evaluation Date field.
    • The container type and open field must be completed in CEMS for all peroxide formers.

Warning Label

A warning label should be affixed to all containers of peroxidizable compounds, as illustrated below, to indicate the date of receipt and the date the container was first opened.


Date Received __________

Date Opened ___________

Discard or test within 1 / 3 / 6 / 12 / 18 months after opening

(circle one)

Storage Procedures

  • Store peroxide formers in a tightly closed (air-tight), amber, properly labeled container away from flames, light, heat, sources of ignition, oxidizers and oxidizing acids. Airtight amber glass containers are recommended.
  • Protect all peroxide formers from physical damage and ignition sources.
  • Do not store in ground glass stopper bottles.
  • If applicable, store peroxides forming chemicals under nitrogen or other inert gas or in an inert atmosphere chamber.  Consult SDS for guidance on storage requirements of individual chemicals.
  • Store in an approved flammable storage cabinet.    
  • Refrigerators used for storage must be explosion-proof or refrigerator approved for the storage of flammable materials.
  • Rotate all stock to prevent aging. Use a first in-first out method.
  • All peroxide formers in storage (opened or unopened) must be at least visually inspected for peroxide formation on at least a monthly basis.
  • Properly dispose of chemicals prior to their maximum safe storage periods.
  • For examples of chemicals listed by group, please click here.

Table 1-Maximum Safe Storage periods for Peroxide Formers

Group A

Group B

Group C

Group D


(see note 1)

12 months

12 months

12 months

18 months

(see note 4)


3 months

3 months

6 months

(see note 2)

24 hours

(see note 3)

3 months

6 months

(see note 2)

12 months

(see note 2)

Note 1: Time from date received or manufacturer stamped expiration date, whichever comes first.

Note 2: Must be tested for peroxide formation on at least a monthly basis and be free of peroxides

Note 3: Uninhibited

Note 4: Recommended maximum storage time. Consult SDS for storage time limits


Use & Handling Procedures

  • Test for the presence of peroxide formers before each use. Do not distill, evaporate or concentrate a peroxide-forming chemical until you have first tested it for the presence of peroxides.  
  • Evaporation or distillation of peroxide forming chemicals will result in concentration of peroxides. It is recommended that distillation cease when about 15-20% of solvent remains in the flask.
  • All lab work involving peroxide-forming chemicals must be done in a properly certified chemicals fume hood or other appropriate exhaust ventilation system.
  • Proper lab attire and personal protective equipment (PPE) must be worn when handling peroxide forming chemicals.
  • Utilize shields, barriers and additional PPE (such as face shields and heavy gloves) where there is a possibility of explosion or vigorous chemical reaction.
  • Do not open a container of a peroxide forming chemical that has obvious crystal formation.  Immediately contact your supervisor.
    • Container has whitish crystals around the cap and/or a viscous liquid or precipitate
    • Solid chemicals show discoloration and/or formation of a surface crust
  • Do not use metal spatulas or magnetic stirring bars with peroxide-forming chemicals. Ceramic, Teflon or wooden equipment is proffered.
  • Purified solvents should be used promptly and not stored for later use.
  • Carefully wipe the container neck, cap and threads with a cloth after each use before resealing.

Evaluation Procedures

All peroxide formers must be evaluated to check for the presence of peroxides. The evaluation should be conducted prior to each use and as needed as defined above in the storage section. 

  • General
    • All evaluations must be documented in CEMS.
    • Proper PPE must be worn when conducting an evaluation.
    • Only those individual who are properly trained by their supervisor or Principal Investigator may conduct an evaluation.
  • Visual Inspection
    • Verify the identity of the chemical and find its appropriate group on the common peroxide forming chemicals list.  Refer to SDS for additional safety information if the chemical is not on the list.
    • Determine the date opened or date received if unopened and compare to Table 1-Maximum safe storage period for Peroxide Former. Continue to Disposal section if chemical is past its maximum safe storage period.
    • Determine if the evaporation of the chemical is known or estimated to be less than 10%. Continue to Disposal section if chemical has evaporated to less than 10% of its original volume. .
    • Inspect the container for visible discoloration, viscous liquids, crystallization (around the cap or in solution), precipitate and or the formation of surface crusts. These are visual signs of peroxide formation. Continue to Disposal section if visual signs of peroxide formation are present.

It is recommended that you do not test for peroxides if the contents of the container have evaporated to less than 10% of its original volume, is past its maximum safe storage, has visual signs of peroxide formation or chemicals origin, age  and/or history is unknown.  The chemical should be considered to be unsafe and should not be disturbed.  

  • Peroxide Testing

NOTE: Do not attempt to force open a rusted or stuck cap on a container of a peroxide forming chemical.

NOTE: The testing of chemicals for peroxide formation must be performed by qualified individuals.

    • Chemicals passing the visual inspection as stated above may be tested for peroxide content.
    • Commercial Test Strips:
      • Peroxide test strips detect inorganic and organic compounds that contain a peroxide or hyper peroxide group.
        • Purchase from: Baxter Scientific Products, 1-800-642-3220, Matheson Scientific, 1-800-328-4523, Spectrum Chemical, 1-800-772-8786, Thomas Scientific, 1-800-345-2100, and VWR Scientific, 1-800-932-5000.
        • Product name: EM Quant Ion Specific Test Strips, Peroxide Test: 0.5-50 mg/L Catalog number and price: EM-10011-1, Pk.100/$30.00.
        • Product name: Baker Test strips, Peroxide (H2O2): 3-100 mg/L. Catalog number and price: JT4416-1, Pk.100/$30.00. (Prices subject to change. Equivalent test strips from other vendors are also acceptable.)
    • Alternate commercial test strips and wet chemical detection methods are also available. Consult your supervisor for appropriate peroxide detection methods.
    • Evaluate levels of peroxide

Peroxide Levels


<25 ppm

Considered safe for general use

25-100 ppm

Not recommended for distilling or otherwise concentrating

100-400 ppm

Avoid handling and submit for proper disposal

>400 ppm

High Risk-Immediately contact EHRS-Do Not Disturb

    • If you suspect unsafe levels of peroxide or a chemical that requires immediate attention.
      • If the container was picked up gently put it down in a safe place.
      • Do not shake the container or place it near sources of heat or ignition.
      •  Tape-off the area containing the potentially shock sensitive compound and warn laboratory personnel of its presence.
      • Immediately contact EHRS at 215-707-2520.

Peroxide Inhibitor

If any peroxides are detected, a "dash" of butylated hydroxy toluene (BHT) should be added to the container to inhibit further peroxidation. Chemicals containing less than 80 ppm peroxides should have the BHT added, unless it is determined that the inhibitor will adversely affect experimental work or cause an unsafe condition.


Chemicals that have been recently tested and contain <25 ppm peroxide levels can typically be disposed of through EHRS.

A “Request to Dispose of Potentially Explosive Chemicals (PEC)” form is required to be completed and submitted to EHRS if any one of the following conditions is met:

  • The container has exceeded its maximum safe storage period as defined in Table 1 in the storage section.
  • The container has failed a visual inspection.
  • Evaporation is known or estimated to have reduced the volume of the chemical to less than 10% of its original volume.
  • Visual signs of peroxide formation in and outside  the container
  • The name, history, or age of the chemical is unknown.
  • The chemical has recently been tested and contains ≥ 25 ppm peroxides
  • As required by EHRS.

Emergency Disposal

The EHRS will have a University approved vendor or the Philadelphia Bomb Squad to remove any containers of peroxide forming chemicals if:

  • the chemical has a peroxide concentration at unsafe levels,
  • the container has crystals in or on it
  • the container is metal with a metal cap,
  • the chemical is suspected to be shock-sensitive due to its age or
  • the chemical is determined or suspected by EHRS to be unstable or otherwise unsafe.

Common Peroxide Formers

A list of common Peroxide Forming Chemicals can be found here.


XIX. Hazardous Waste Procedures

The EHRS Handbook (Section 2) and Hazardous Waste Guide describes the requirements for managing waste. Specific polices on waste such as gas cylinder( EHRS 2.7), Hazardous Lamps (EHRS Handbook 2.12). etc.. The Supervisor, PI, Department Head or Manager is responsible for making the determination that it is a waste. All hazardous chemicals must be disposed through the EHRS. The definition for hazardous chemicals is located in Section II on page 4. Please contact the EHRS at 215-707-2520 or 2-2520 if you have any questions.


All hazardous waste containers must have a label that states "HAZARDOUS WASTE," and the chemical name(s) . This labeling MUST BE DONE PRIOR to placing any waste in the container. When naming the wastes, be specific, e.g., Xylene, Mineral Spirits, etc., instead of a more general term like Non-Halogenated Solvents, for example. Do not use abbreviations or chemical formulas. Hazardous waste labels are available from EHRS (2-2520), or you can use laboratory tape, etc., as long as the label clearly indicates that the content of the container and identifies the specific names of the waste materials.

Generally the best containers for hazardous waste are the ones that the materials originally came in. Other containers, such as 5-gallon jugs, are acceptable as long as the containers and any residue left inside are compatible with the waste material. All containers must have tight-fitting lids or ground glass stoppers and no corks. Parafilm or corks is not a substitute for a tight fitting lid. The EHRS staff will not pick up containers that do not have tight-fitting lids. The EHRS has some waste container that can be provided to you.

When not actually pouring waste into or out of the container, the top must be securely fastened. You cannot leave a funnel sitting in the container. The only exception to this is for processes such as HPLC that runs and adds waste to the container continuously. When the HPLC process is not running, the lid must be on.

Empty chemical containers need to be rinsed 3 times with clean water. Acutely hazardous (40 CFR 261.33(e)) chemical containers must also be rinsed 3 times. However, the rinsed water must be collected and treated as hazardous waste. The labels must be defaced or removed before empty containers can be placed into the municipal waste stream.

At no time may more than 55 gallons of hazardous waste or 1 quart of acutely hazardous waste (40 CFR 261.33(e)) be allowed to accumulate in any area prior to waste pickup by EHRS. Waste must be stored in a secure place where it is always under the control of lab personnel. Waste stored outside the lab must be stored in the immediate vicinity of the laboratory or work area. In addition, waste must be kept behind lock and key, inspected and kept in a clean location. Waste must be stored in secondary containers.

Waste containers can not be stored over drains or in sinks. Waste must not be stored on the floor. Waste should not be stored with "good" chemicals. You can only store compatible wastes in the same containers. Halogenated (chlorinated) and mercuric waste are incompatible and chemicals should be kept separate from non-halogenated wastes because they are incompatible. The examples below are incompatible wastes:

  • Elemental metals/hydrides and acids/alcohols;
  • Cyanides and acids;
  • Sulfides and acids;
  • Oxidizers and flammable;
  • Acids and bases;
  • Acids and flammable;
  • Acids and chlorine compounds;
  • Amines and chlorine compounds;
  • Water or air reactives and anything; and
  • Phenol and formaldehyde.

This list is not all-inclusive: if in doubt do not mix! You should always consult the SDS, contact EHRS at 2-2520 or contact other chemical information sources for compatibility information.

Disposal of Hazardous Waste

To dispose of any hazardous waste, you must completely fill out the EHRS Hazardous/Chemical Waste Removal Request Form and fax the completed form to EHRS at 2-1600 or submit electronically at Untrained employees who lack knowledge of the chemicals should not complete the Hazardous/Chemical Waste Removal Form. The form must be filled out as completely as possible and all information must be printed legibly or typed. Waste will not be picked up without a completed Hazardous/Chemical Waste Removal form. Materials that are no longer needed should be given to EHRS for recycling or disposal. Containers with illegible labels and chemicals that appear to have deteriorated should be given to EHRS for disposal. Upon the termination, transfer, etc., of a given PI, arrangements must be made to transfer all hazardous materials to the EHRS.

Hazardous Waste Minimization

Applicable law requires that all generators who create hazardous waste adopt a plan to reduce both the volume and toxicity of hazardous wastes. EHRS will assist you in adopting a proper plan to minimize waste that you generate.

Each lab or area must develop and implement a hazardous waste minimization program. Details of the program must be recorded in the CHG worksheet and be made available for review upon request.

Examples of waste minimization are:

  • Substitution - replacing toxic or other hazardous materials used in processes with less or non-hazardous substances. This is the best way to minimize your hazardous waste. Example: using Alconox instead of sulfuric/chromic acid glass cleaners;
  • Microchemistry - using minute quantities and small-scale chemistry instead of large amounts of chemicals in laboratory experiments;
  • Redistilling - reclaiming solvents for reuse by a distilling process in the laboratory. This also is a great way to cut costs as you cut the cost of replacement solvents drastically;
  • Recycling/Redistribution – redistributing chemicals that are unused or unopened to other labs or work areas for reuse, saving both disposal costs and new product costs for another researcher; and
  • Laboratory Destruction – neutralizing chemicals or exempting them from hazardous waste regulations by treatment or alteration in the laboratory. An example of lab destruction is neutralizing strong acids or alkalines with a buffering solution as part of an experiment that required or created such materials. Lab destruction must be done as part of the experiment and must be done according to published, recognized methods. Contact EHRS at 2-2520 for safety and approved method of destruction prior to attempting laboratory destruction.

XX. Record Keeping Requirements

The CHG worksheet, plans, documents and all other associated records must be readily available for review upon request. It is the responsibility of the Supervisor, PI, Department head or Manger to ensure that they are completed and in an easily auditable format.

Appendix A-Glossary

ACGIH - The American Conference of Governmental Industrial Hygienists is a voluntary membership organization of professional industrial hygiene personnel in governmental or educational institutions. The ACGIH develops and publishes recommended occupational exposure limits each year called Threshold Limit Values (TLV's) for hundreds of chemicals, physical agents, and biological exposure indices.

ACUTE - Short duration, rapidly changing conditions.

ACUTE EXPOSURE - An intense exposure over a relatively short period of time.

ANSI - The American National Standards Institute is a voluntary membership organization (run with private funding) that develops consensus standards nationally for a wide variety of devices and procedures.

ASPHYXIANT - A chemical (gas or vapor) that can cause death or unconsciousness by suffocation. Simple asphyxiants, such as nitrogen, either remove or displace oxygen in the air. They become especially dangerous in confined or enclosed spaces. Chemical asphyxiants, such as carbon monoxide and hydrogen sulfide, interfere with the body's ability to absorb or transport oxygen to the tissues.

BOILING POINT - The temperature at which the vapor pressure of a liquid equals atmospheric pressure or at which the liquid changes to a vapor. The boiling point is usually expressed in degrees Fahrenheit. If a flammable material has a low boiling point, it indicates a special fire hazard.

"C" OR CEILING - A description usually seen in connection with ACGIH exposure limits. It refers to the concentration that should not be exceeded, even for an instant. It may be written as TLV-C or Threshold Limit Value-Ceiling. (See also THRESHOLD LIMIT VALUE).

CARCINOGEN - A substance or physical agent that may cause cancer in animals or humans.

C.A.S. NUMBER - Identifies a particular chemical by the Chemical Abstracts Service, a service of the American Chemical Society that indexes and compiles abstracts of worldwide chemical literature called Chemical Abstracts.

cc - Cubic centimeter, a volumetric measurement which is also equal to one milliliter (ml).

CHEMICAL - As broadly applied to the chemical industry, an element or a compound produced by chemical reactions on a large scale for either direct industrial and consumer use or for reaction with other chemicals.

CHEMICAL REACTION - A change in the arrangement of atoms or molecules to yield substances of different composition and properties. (see REACTIVITY)

CHRONIC - Persistent, prolonged or repeated conditions.

CHRONIC EXPOSURE - A prolonged exposure occurring over a period of days, weeks, or years.

COMBUSTIBLE - According to the DOT and NFPA, combustible liquids are those having a flash point at or above 100oF (37.8oC), or liquids that will burn. They do not ignite as easily as flammable liquids. However, combustible liquids can be ignited under certain circumstances, and must be handled with caution. Substances such as wood, paper, etc., are termed "Ordinary Combustibles".

CONCENTRATION - The relative amount of a material in combination with another material. For example, 5 parts of (acetone) per million (parts of air).

CORROSIVE - A substance that, according to the DOT, causes visible destruction or permanent changes in human skin tissue at the site of contact or is highly corrosive to steel.

CUBIC METER (m3) - A measure of volume in the metric system.

CUTANEOUS - Pertaining to or affecting the skin.

DECOMPOSITION - The breakdown of a chemical or substance into different parts or simpler compounds. Decomposition can occur due to heat, chemical reaction, decay, etc.

DERMAL - Pertaining to or affecting the skin.

DERMATITIS - An inflammation of the skin.


DOT - The United States Department of Transportation is the federal agency that regulates the labeling and transportation of hazardous materials.

DYSPNEA -Shortness of breath; difficult or labored breathing.

EHRS-Environmental Health and Radiation Safety

EPA - The Environmental Protection Agency is the governmental agency responsible for administration of laws to control and/or reduce pollution of air, water, and land systems.

EPA NUMBER - The number assigned to chemicals regulated by the Environmental Protection Agency (EPA).

EPIDEMIOLOGY - The study of disease in human populations.

ERYTHEMA - A reddening of the skin.

EVAPORATION RATE - The rate at which a material is converted to vapor (evaporates) at a given temperature and pressure when compared to the evaporation rate of a given substance. Health and fire hazard evaluations of materials involve consideration of evaporation rates as one aspect of the evaluation.

oF - Degrees, Fahrenheit; a temperature scale.

FLAMMABLE LIQUID - According to the DOT and NFPA a flammable liquid is one that has a flash point below 100oF. (See FLASH POINT)

Classes Of Flammable Liquids

Flammable Solvent Class

Boiling Point

Flash Point

Class 1A

< 100oF

< 73oF

Class 1B

>= 100oF

< 73oF

Class 1C

>= 100oF

Between 73 and 100oF

FLASH POINT - The lowest temperature at which a liquid gives off enough vapor to form an ignitable mixture with air and burn when a source of ignition (sparks, open flames, cigarettes, etc.) is present. Two tests are used to determine the flash point: open cup and closed cup. The test method is indicated on the SDS after the flash point.

g - See GRAM.

GENERAL VENTILATION - Also known as general exhaust ventilation, this is a system of ventilation consisting of either natural or mechanically induced fresh air movements to mix with and dilute contaminants in the workroom air. This is not the recommended type of ventilation to control contaminants that are highly toxic, when there may be corrosion problems from the contaminant, when the worker is close to where the contaminant is being generated, and where fire or explosion hazards are generated close to sources of ignition (See LOCAL EXHAUST VENTILATION).


GRAM (g) - A metric unit of weight. One ounce equals 28.4 grams.

GRAMS PER KILOGRAM (g/Kg) - This indicates the dose of a substance given to test animals in toxicity studies. For example, a dose may be 2 grams (of substance) per kilogram of body weight (of the experimental animal).

HAZARDOUS MATERIAL - Any substance or compound that has the capability of producing adverse effects on the health and safety of humans.

IGNITABLE - A solid, liquid or compressed gas that has a flash point of less than 140oF. Ignitable material may be regulated by the EPA as a hazardous waste, as well.

INCOMPATIBLE - The term applied to two substances to indicate that one material cannot be mixed with the other without the possibility of a dangerous reaction.

INGESTION - Taking a substance into the body through the mouth, such as food, drink, medicine, or unknowingly as in contaminated hands or cigarettes, etc.

INHALATION - Breathing in of an airborne substance that may be in the form of gases, fumes, mists, vapors, dusts, or aerosols.

INHIBITOR - A substance that is added to another to prevent or slow down an unwanted reaction or change.

IRRITANT - A substance that produces an irritating effect when it contacts skin, eyes, nose, or respiratory system.


KILOGRAM (Kg) - A unit of weight in the metric system equal to 2.2 pounds.

L - See LITER.




LETHAL CONCENTRATION50 - The concentration of an air contaminant (LC50) that will kill 50 percent of the test animals in a group during a single exposure.

LETHAL DOSE50 - The dose of a substance or chemical that will (LD50) kill 50 percent of the test animals in a group within the first 30 days following exposure.


LITER (L) - A measure of capacity. One quart equals .9 liters.

LOCAL EXHAUST VENTILATION - (Also known as exhaust ventilation.) A ventilation system that captures and removes the contaminants at the point where they are being produced before they escape into the workroom air. The system consists of hoods, ducts, a fan and possibly an air cleaning device. Advantages of local exhaust ventilation over general ventilation include: it removes the contaminant rather than dilutes it; it requires less air flow and thus is more economical over the long term; and the system can be used to conserve or reclaim valuable materials. However, the system must be properly designed with the correctly shaped and placed hoods, and correctly sized fans and duct work.

LOWER EXPLOSIVE LIMIT (LEL) - (Also known as Lower Flammable Limit). The lowest concentration of a substance that will produce a fire or flash when an ignition source (flame, spark, etc.) is present. It is expressed in percent of vapor or gas in the air by volume. Below the LEL or LFL, the air/contaminant mixture is theoretically too "lean" to burn. (See also UEL).


MELTING POINT - The temperature at which a solid changes to a liquid. A melting range may be given for mixtures.




MILLIGRAM (mg) - A unit of weight in the metric system. One thousand milligrams equal one gram.

MILLIGRAMS PER CUBIC METER - Units used to measure air (mg/m3) concentrations of dusts, gases, mists, and fumes.

MILLIGRAMS PER KILOGRAM - This indicates the dose of a substance (mg/kg) given to test animals in toxicity studies. For example, a dose may be 2 milligrams (of substance) per kilogram of body weight (of the experimental animal).

MILLILITER (ml) - A metric unit used to measure capacity. One milliliter equals one cubic centimeter. One thousand milliliters equal one liter.


MSHA - The Mine Safety and Health Administration; a federal agency that regulates the mining industry in the safety and health area.

MUTAGEN - Anything that can cause a change (or mutation) in the genetic material of a living cell.

NARCOSIS - Stupor or unconsciousness caused by exposure to a chemical.

NFPA - The National Fire Protection Association is a voluntary membership organization whose aims are to promote and improve fire protection and prevention. NFPA has published 16 volumes of codes known as the National Fire Codes. Within these codes is Standard No. 704, Identification of the Fire Hazards of Materials. This is a system that rates the hazard of a material during a fire. These hazards are divided into health, flammability, and reactivity hazards and appear in a well-known diamond system using from zero through four to indicate severity of the hazard. Zero indicates no special hazard and four indicates severe hazard.

NIOSH - The National Institute of Occupational Safety and Health is a federal agency that among its various responsibilities trains occupational health and safety professionals, conducts research on health and safety concerns, and tests and certifies respirators for workplace use.

ODOR THRESHOLD - The minimum concentration of a substance at which a majority of test subjects can detect and identify the substance's characteristic odor.

ORAL - Having to do with the mouth.

OSHA - The Occupational Safety and Health Administration - a federal agency under the Department of Labor that publishes and enforces safety and health regulations for most businesses and industries in the United States.

OXIDATION - The process of combining oxygen with some other substance to a chemical change in which an atom loses electrons.

OXIDIZER - Is a substance that gives up oxygen easily to stimulate combustion of organic material.

OXYGEN DEFICIENCY - An atmosphere having less than the normal percentage of oxygen found in normal air. Normal air contains 21% oxygen at sea level.

PADEP- Pennsylvania Department of Environmental Protection


PERMISSIBLE EXPOSURE LIMIT (PEL) - An exposure limit that is published and enforced by OSHA as a legal standard. PEL may be either a time-weighted-average (TWA) exposure limit (8 hour), a 15-minute short term exposure limit (STEL), or a ceiling (C). The PEL's are found in Tables Z-1, Z-2, or Z-3 of OSHA regulations 1910.1000. (See also TLV).

PERSONAL PROTECTIVE EQUIPMENT - Any devices or clothing worn by the worker to protect against hazards in the environment. Examples are respirators, gloves, and chemical splash goggles.

POLYMERIZATION- A chemical reaction in which two or more small molecules combine to form larger molecules that contain repeating structural units of the original molecules. A hazardous polymerization is the above reaction with an uncontrolled release of energy.

ppm - Parts (of vapor or gas) per million (parts of air) by volume.

REACTIVITY - A substance's susceptibility to undergoing a chemical reaction or change that may result in dangerous side effects, such as explosions, burning, and corrosive or toxic emissions. The conditions that cause the reaction, such as heat, other chemicals, and dropping, will usually be specified as "Conditions to Avoid" when a chemical's reactivity is discussed on a SDS.

RESPIRATOR - A device which is designed to protect the wearer from inhaling harmful contaminants.

RESPIRATORY HAZARD - A particular concentration of an airborne contaminant that, when it enters the body by way of the respiratory system or by being breathed into the lungs, results in some bodily function impairment.

SENSITIZER - A substance that may cause no reaction in a person during initial exposures, but afterwards, further exposures will cause an allergic response to the substance.

SHORT TERM EXPOSURE LIMIT - Represented as STEL or TLV-STEL, this is the maximum concentration to which workers can be exposed for a short period of time (15 minutes) for only four times throughout the day with at least one hour between exposures. Also the daily TLV-TWA must not be exceeded.

"SKIN" - This designation sometimes appears alongside a TLV or PEL. It refers to the possibility of absorption of the particular chemical through the skin and eyes. Thus, protection of large surface areas of skin should be considered to prevent skin absorption so that the TLV is not invalidated.

STEL - Short Term Exposure Limit.

SUBSTANCE - Any chemical entity.

SYNONYM - Another name by which the same chemical may be known.

SYSTEMIC - Spread throughout the body; affecting many or all body systems or organs; not localized in one spot or area.

TERATOGEN - An agent or substance that may cause physical defects in the developing embryo or fetus when a pregnant female is exposed to that substance.

THRESHOLD LIMIT VALUE - Airborne concentrations of substances devised by the ACGIH that represent conditions under which it is believed that nearly all workers may be exposed day after day with no adverse effect. TLV's are advisory exposure guidelines, not legal standards, that are based on evidence from industrial experience, animal studies, or human studies when they exist. There are three different types of TLV's: Time Weighted Average (TLV-TWA), Short Term Exposure Limit (TLV-STEL) and Ceiling (TLV-C). (See also PEL.)

TIME WEIGHTED AVERAGE - The average time, over a given work period (e.g. 8-hour work day), of a person's exposure to a chemical or an agent. The average is determined by sampling for the contaminant throughout the time period. Represented as TLV-TWA.


TOXICITY - The potential for a substance to exert a harmful effect on humans or animals and a description of the effect and the conditions or concentrations under which the effect takes place.

TRADE NAME - The commercial name or trademark by which a chemical is known. One chemical may have a variety of trade names depending on the manufacturers or distributors involved.




UNSTABLE LIQUID - A liquid that, in its pure state or as commercially produced, will react vigorously in some hazardous way under shock conditions (i.e., dropping), certain temperatures, or pressures.

UPPER EXPLOSIVE LIMIT - Also known as Upper Flammable Limit. Is the highest concentration (expressed in percent of vapor or gas in the air by volume) of a substance that will burn or explode when an ignition source is present. Theoretically above this limit the mixture is said to be too "rich" to support combustion. The difference between the LEL and the UEL constitutes the flammable range or explosive range of a substance. That is, if the LEL is 1ppm and the UEL is 5ppm, then the explosive range of the chemical is 1ppm to 5ppm. (see also LEL).

VAPOR - The gaseous form of substances which are normally in the liquid or solid state (at normal room temperature and pressure). Vapors evaporate into the air from liquids such as solvents. Solvents with low boiling points will evaporate.

Appendix B-Toxicology Overview

Chemical Toxicity

Toxicology is the study of the nature and action of chemical substances on living systems. Toxicity is the ability of a chemical molecule or compound to produce injury once it reaches a susceptible site in or on the body. Hazard is the probability or likelihood that injury will occur considering the manner in which the substance is used.

Dose-Response Relationships

The potential toxicity (harmful action) inherent in a substance is manifest only when that substance comes in contact with a susceptible living biological system. A chemical normally thought of as "harmless" will evoke a toxic response if added to a biological system in sufficient amount. The toxic potency of a chemical is defined by the relationship between the dose (the amount) of the chemical and the response that is produced in a biological system.

Routes of Entry into the Body

There are three main routes by which hazardous chemicals enter the body:

  • absorption through the respiratory tract through inhalation.
  • absorption or injection through the skin or eyes.
  • absorption through the digestive tract. This can occur through eating or smoking with contaminated hands or in contaminated work areas.

Most exposure standards, Threshold Limit Values (TLVs) and Permissible Exposure Limits (PELs), are based on the inhalation route of exposure. They are normally expressed in terms of either parts per million (ppm) or milligrams per cubic meter (mg/m3) concentration in air.

If a significant route of exposure for a substance is through skin contact, the SDS will have a "skin" notation associated with the listed exposure limit. Examples include: some pesticides, carbon disulfide, phenol, carbon tetrachloride, dioxane, mercury, thallium compounds, ethylene, hydrogen cyanide.

Health Effects

Acute poisoning is characterized by rapid absorption of the substance and the exposure is sudden and severe. Normally, a single large exposure is involved. Examples: carbon monoxide or cyanide poisoning.

Chronic poisoning is characterized by prolonged or repeated exposures of a duration measured in days, months or years. Symptoms may not be immediately apparent. Examples: lead or mercury poisoning or pesticide exposure.

“Local” refers to the site of action of an agent and means the action takes place at the point or area of contact. The site may be skin, mucous membranes, the respiratory tract, gastrointestinal system, eyes, etc. Absorption does not necessarily occur. Examples: some strong acids or alkalis.

“Systemic” refers to a site of action other than the point of contact and presupposes absorption has taken place. For example, an inhaled material may act on the liver. Example: arsenic affects the blood, nervous system, liver, kidneys and skin.

Cumulative poisons are characterized by materials that tend to build up in the body as a result of chronic exposure. The effects are not seen until a critical body burden is reached.

Example: heavy metals (such as Lead).

Synergistic responses: When two or more hazardous material exposures occur, the resulting effect can be greater than the effect of the individual exposures. Example: exposure to both asbestos and tobacco smoke, producing lung cancer or mesothelioma.

Other Factors Affecting Toxicity

Rate of entry and route of exposure (how fast the toxic dose is delivered and by what means) are important factors. A person’s age can affect the capacity to repair tissue damage. Previous exposures can lead to tolerance or increased sensitivity.

General state of health, physical condition, and life style, can affect the toxic response. Preexisting disease can result in increased sensitivity.