General Laboratory Safety


The laboratories of the college of Saint Benedict and Saint John's University require hazard containment of biological, chemical and physical hazards. This document addresses policies and procedures relevant to most of our laboratory situations. Policies and procedures relevant to a specific situation or program (e.g. chemical hygiene plan, blood-borne pathogens exposure control plan) are addressed in separate documents.

The success of a laboratory safety program depends on every employee's participation and cooperation. Nonconformity with safety precautions not only endangers the individual, but often compromises the health and safety of fellow workers, students and the surrounding community, and may result in loss of experimental integrity and property damage.


Dean of colleges, CSB/SJU
Is responsible for enforcing and regulating the laboratory safety program.

Environmental Health and Safety
The Environmental Health and Safety/Safety office for academic programs provides staff support for the Dean in all matters relating to safety in the academic programs.

Department Chair
Is responsible for ensuring that all laboratory activities under her or his control are conducted in a manner that presents the least possible hazard to employees, students and the surrounding community. The Chair must ensure that all safety policies and regulations are enforced and that necessary safety equipment is available in the laboratory.

Laboratory Supervisor or Project Director
Has the primary responsibility for the health and safety of all program personnel under her/his jurisdiction including CSB/SJU employees, students and visitors. The responsibilities include:

  • Identification of hazards and assessment of the risks associated with operations;
  • Ensuring that program personnel are aware of hazards and of the precautions they should take in carrying out their assigned tasks;
  • Selection of proper laboratory safety practices and engineering controls necessary to minimize personal injury or property damage;
  • Providing instruction and training programs for personnel in the practices and techniques required for their assigned tasks and laboratory operations;
  • Maintaining a laboratory procedure notebook;
  • Ensuring that necessary safety equipment is available in the laboratory, used when required, and adequately maintained;
  • In conjunction with department safety committee or academic safety officer, establish and periodically review emergency procedures for accidental spills and any overt exposure to hazardous substances;
  • for immediate medical attention for injured personnel and reporting of incidents as required;
  • with all policies and procedures as outlined in this manual.

Individual Employees
Each employee's responsibilities include:

  • Complying with all CSB/SJU safety policies and procedures;
  • Maintaining awareness of the risks associated with assigned duties;
  • Taking all necessary and appropriate safety precautions relevant to performance of duties;
  • Becoming familiar with emergency procedures prior to accidental spills, overt personal exposures, fire, etc.;
  • unsafe conditions or practices to the project director, department safety committee or academic safety officer;
  • all incidents resulting in injury or exposure to hazardous agents (physical, chemical or biological) to the project director or supervisor. First Injury report form must be completed.

Projects Review/Approval Mechanisms

All proposed projects and activities that have the potential for health hazards at CSB/SJU laboratory should be submitted to department safety and health committee or safety officer for review and must be approved by the department chair. The purposes of such a review are:

  • To identify hazards and assess the risks associated with the project or activity;
  • evaluate the adequacy of safety procedures, the facilities, and the equipment; and
  • need for preventive medical measures.

When Review is Required
Before beginning of any proposed project or new procedure involving the use of hazardous substances or physically harmful agents, the review process will be necessary when:

  • An existing technique, material/chemical or equipment is to be modified and the project director believes that the modification may increase risk to laboratory personnel;
  • An infectious agent (known or potential) is to be used or the risk of chemical or physical hazards are high such that vaccination or specialized personnel equipment or training prior to onset of work is necessary, or
  • A new technique, material, equipment and/or procedure is introduced, that may increase the risk to laboratory personnel.

Review Procedure 

  • The project director should submit one copy of the proposed project to the department safety committee or in the absence of safety committee, to the academic safety officer.
  • The department safety committee or the academic safety officer will evaluate the project protocol, facility design equipment, workspace, and other pertinent information for safety and submit a recommendation to the chair.
  • The project director will be advised by the department chair concerning the acceptability of the protocol and any modifications, additions, etc. required.
  • The department chair will issue the project director a clearance to begin work when all work hazards are satisfactorily identified and controlled.


  • Projects that involve the use of radioisotopes regulated by the NRC are currently not permitted at the CSB/SJU.

Identification and Control of Hazardous Areas

A. Controlled Access

Certain areas within CSB/SJU laboratory facilities have been designated restricted and access is controlled. To prevent unauthorized personnel from entering restricted areas, a key, issued to each person officially needing access to a controlled area, permits entry. Other employees requesting keys to access a restricted area should sought recommendation from department safety committee and obtain approval from the department chair.

B. Hazard Warning Signs and Labels (ANSI Z535)

Hazard Categories
Hazard identification signage has four distinct categories:

NOTICE – Written on a blue background, states a policy related to safety of personnel or protection or property but is not for use with a hazard a hazardous situation.

CAUTION – Written on a yellow background, indicates a potentially hazardous situation that, if not avoided, may result in minor or moderate injury.

WARNING – written on orange background, indicates a potentially hazardous situation that, if not avoided, could result in death or serious injury.

DANGER – written on red background, indicates an imminently hazardous situation that, if not avoided, will result in death or serious injury. Limited to the most extreme situations.

A Description on Green Background indicates general instructions related to safe work practices, reminders of proper safety procedures, or the location of safety equipment.

General Information

Prominent signs and labels of the following types are generally posted in and adjacent to laboratories: a) emergency phone numbers of emergency personnel/ facilities, b) identity labels, showing contents of containers and associated hazards; c) location signs for safety showers, eyewash stations, other safety and first aid equipment, and exits; and d) warnings at areas or equipment where special or unusual hazards exist. Some of the more common hazards found in laboratories that are required to be or should be identified are biohazards, radiation hazards, laser light, chemical hazards, explosive or flammable liquids, cryogenic hazards, compressed gas storage, noise hazards, and UV light.

Posting of Hazard Signs and Labels

The laboratory supervisor, laboratory manager or department safety committee may post hazard warning signs as necessary and in compliance with the requirements for each type of hazard encountered. Environmental Health and Safety Office can assist with information on proper types of signs and specific requirements for signage.

Procedures for posting

  1. Signs must be posted only while a hazard exists and must be removed as  soon as the source of danger is removed.
  2. Hazard warning signs should show the name(s) of the hazard(s) and the project director, her/his alternate, with their home telephone numbers.
  3. The project director named on the hazard sign will determine when visitors can be allowed in the laboratory.
  4. Signs that are to be used permanently must be posted in permanent frames. Contact the Environmental Health and Safety Office or the Physical Plant for assistance in installation.
  5. Signs that are to be posted on a temporary bases (less than one month) may be installed in permanent frames or posted with tape on appropriate surfaces.
  6. Hazard warning signs can be requested from the Environmental Health and Safety Office.

Hazard Containment

A. General

Facility design, safety equipment, and practices for containing laboratory hazards vary according to the nature of the agent/substance, the volume and concentration handled, and the manipulation procedures used.

Hazard containment requirements must be considered case by case and are determined by the needs of the project director based on experience gained from work conditions, and on appropriate guidelines established for the department.

B. Types of Hazards

  • Biological Hazards (Reference Institutional Bloodborne Pathogen Program)
  • Chemical Hazards (Reference Department Chemical Hygiene Plan)

C. Ventilation Controls

Fume hoods, Biological Safety Cabinets (BSCs) and ventilated cabinets are primary containment devices designed to protect workers from exposure to hazards. They provide physical barriers and directional airflow that prevents or minimizes worker contact with hazards.

1. Biological Safety Cabinet - Description

Biological safety cabinets are ventilated boxes which give the workers a degree of protection against hazardous aerosols generated within. The following terms are used to describe the cabinet features:

  • "Total containment or barrier" means the cabinet was designed to permit no hazardous particles to reach the laboratory environment.
  • "Partial containment or barrier" means the cabinet was designed to prevent almost all infectious particles from reaching the laboratory environment.
  • "Personal protection" means the laboratory worker is protected to some degree from exposure to hazardous aerosols generated within the cabinet.
  • "Product protection" applies to reduction of the risk of contamination of the specimen or culture handled in the cabinet. (Biological safety cabinets supplying HEPA-filtered air to the work area provide product protection; vertical laminar flow supply air reduces the likelihood of cross-contamination.)
  • Air intake" refers to the opening where air enters the cabinet.
  • "High efficiency particulate air (HEPA)" filters remove particles at least 0.3 microns in size from an air stream at an efficiency of 99.97 or greater.

Cabinet classes

    a. Class I cabinets provide partial personnel protection and no product protection and are suitable for handling low-to-moderate risk bio-hazardous aerosols when product protection is not essential. Small amounts of toxic or flammable chemicals may be used as air is not re-circulated. Cabinets are connected to the building exhaust system and depend on its operation to exhaust air. Air velocity at the front opening is approximately 75 linear feet per minute.

    b. Class II cabinets provide both product and partial personnel protection and are designed for the handling of low and moderate-risk biohazards. Type B-2 cabinets do not re-circulate any air within the cabinet and are more suitable for handling carcinogens and other hazardous chemicals than either Type A or Type B-1 cabinets. Class II, Type B-1 cabinets may occasionally be used to handle small quantities of toxic and volatile chemicals.

    c. Class III Cabinets Class III biological safety cabinets, or glove boxes, are closed-front, gas-tight boxes. Employees work using impermeable gloves attached to cabinet-front openings or operating ports. One or two HEPA filters move contaminated air into an exhaust system. The cabinet is maintained under negative pressure compared to the laboratory, and air will tend to enter the cabinet should a leak occur. Class III cabinets provide the highest degree of personnel protection and a clean work environment, and are suitable for use with highly biohazardous agents.

2. Laminar Flow Hoods

Laminar flow hoods are designed to provide a flow of HEPA-filtered air from the cabinet interior over the work surface, directly towards the operator. Toxic chemicals, allergens, infectious agents, and other potential airborne hazards must not be handled in laminar flow hoods because the hood does not protect the operator. Use these cabinets only for procedures such as sterile filter assembly and other jobs requiring product protection. Using clean air stations for tissue culture preparation is not recommended because cell cultures may contain infectious agents and allergens.

3. Fume Hoods and Chemical Glove Boxes

Fume hoods or chemical glove boxes should be used when handling chemical hazards. Fume hoods are usually connected to the building laboratory exhaust system and may not operate outside normal working hours. (Refer to CHP for detailed information)

4. Other Local Exhaust Ventilation Systems

Specialized ventilation systems, such as small, HEPA-filtered enclosures, elephant trunks, and canopy hoods, may be required in certain instances to control fine powders or processes which release heat or vapors which cannot be placed within a conventional chemical fume hood or biological safety cabinet. At CSB/SJU these are mostly found in Art and Theater studios.

Control of Air Flow in Laboratory Areas

A. Single-pass ventilation is supplied to all laboratory areas, unless otherwise noted.

Doors to laboratories must be kept closed, as containment of hazardous materials is partially dependent on proper balance of airflow. Disruption of the positive pressure in the corridor by a laboratory door opened for an extended period of time may result in transmission of airborne materials from the laboratory to the corridor.

B. Hours of Operation of Air-Handling System

The ventilation systems, including fume hoods and biological safety cabinet exhausts, routinely operate during normal working hours, Monday through Friday. Time of operations may vary by facility. Verify hours of operation with the Physical Plant at each facility or contact the academic safety officer.

Laboratory employees must not continue to work after regular operating hours of air-handling systems unless prior arrangements have been made with the Physical Plant to maintain ventilation in the area.

C. Ventilation Failure

In the event of failure of the laboratory ventilation system:

  • Immediately stop working with hazardous substance.
  • Contain the hazards.
  • Leave the laboratory.
  • Notify the HVAC manager, CSB (363- 5101 or 5291) and SJU (363-3306 or 3303).

Safe Work Practices

A. Policy

The following procedures are standard and to all CSB/SJU laboratories. Additional information on chemical and biological methods, procedures, and hazards are found in Department specific CHP or Institutional BBP-ECP.

B. Hygiene

  1. Mouth pipetting is prohibited.
  2. Eating, drinking, chewing gum, smoking, application of makeup or storage of food is prohibited in laboratories.
  3. The use of Universal Precautions are required for handling of all human blood and body fluids specimens for hematologic, microbiologic, chemical and serologic testing.

C. Sharps

  1. Recapping of needles is prohibited.
  2. Disposal of syringes and needles into waste cans, plastic bags, trash baskets or other containers other than as described below is prohibited.
  3. Used syringes and needles are to be deposited, without recapping, directly into puncture resistant containers.
  4. Sharp objects such as syringe needles, glass pasteur pipettes, etc. should only be used when there is no alternative available.

D. Miscellaneous

  1. Suction flasks must be properly shielded and trapped.
  2. All technical procedures must be performed in ways that minimize the creation of aerosols.
  3. Water baths and suction flasks must contain disinfectant if they are used to handle infectious agents.
  4. Desk work using writing materials, reference books, and journals must be avoided in laboratory areas where these materials could become contaminated with hazardous agents.

Personal Protective Equipment

A. Laboratory Clothing

  1. Employees must wear protective clothing appropriate for agents/substances handled in the laboratory.
  2. Impermeable aprons must be used over regular laboratory clothing when handling hot liquids, very cold substances such as liquid nitrogen, or hazardous chemicals such as corrosives.
  3. Keep laboratory coats in the laboratory areas.
  4. Lab coats must be laundered or disposed of in an appropriate manner. Home laundering of laboratory coats and other protective clothing is not permitted.
  5. Front opening laboratory coats must be worn closed when performing laboratory procedures.

B. Gloves

  1. Gloves providing protection against specific chemical agents, extreme temperatures, and barriers to skin, are available.
  2. Proper selection of gloves is important. The Environmental Health and Safety can provide information on types of gloves that are best suited for specific purposes.
  3. Disposable gloves must be discarded after handling chemical and biological hazards.
  4. Disposable gloves used to handle biohazards must be discarded into a biohazardous waste receptacle and decontaminated before disposal.
  5. Hand washing is required after removal of gloves.
  6. Reusable gloves must be cleaned or decontaminated and stored in a clean area.
  7. Gloves used to handle chemical and biological hazards are potentially contaminated and must be removed before the worker opens refrigerators, incubators, room doors, or answers the telephone.

C. Eye and Face Protection

Eye protection and/or face protection must be worn in areas posted as "Eye Hazard Areas".
These areas include where:

  • Corrosive or caustic materials are handled.
  • Explosive materials are handled.
  • Hollow glassware is under vacuum or pressure.
  • Cryogenic materials are handled.
  • Processes can produce aerosols of infectious agents.
  • Flying particles may be generated (grinders, mills, power saws, drill presses, lathes, etc.).
  • Gas or electrical welding is done.
  • Molten metal is used or metal is melted (soldering, leading joints, etc.).  

OSHA requirements (29 CFR 1910.133)

OSHA regulations require each affected employee to use appropriate eye or face protection when exposed to eye or face hazards from flying particles, molten metal, liquid chemicals, acids or caustic liquids, chemical gases or vapors, or potentially injurious light radiation.

Also, OSHA requires that each affected employee who wears prescription lenses while engaged in operations that involve eye hazards shall wear eye protection that incorporates the prescription in its design, or shall wear eye protection that can be worn over the prescription lenses (goggles, faceshield) without disturbing the proper position of the prescription lenses or the protective lenses.

  1. Eye and Face Protective Equipment
    Various types of safety face and eye shields, safety glasses, and goggles are used to protect workers from flying fragments, dusts, liquid splashes, aerosols, vapors and gases. They may be used alone or in conjunction with other protective devices such as respirators. Eye protection should conform to American National Standards Institute, Z87.1-1994. 
  2. Contact Lenses
    Contact lenses do not provide eye protection and may increase risk if exposed to a hazardous agent. The capillary space between the contact lenses and the cornea may trap material present on the surface of the eye. Hazardous agents trapped in this space cannot be washed off the surface of the cornea. If the material in the eye is painful or the contact lens is displaced, muscle spasms will make it very painful to remove the lens. Contact lenses must not be worn by persons exposed to hazardous chemicals unless goggles and/or face shields are also worn to provide full protection.
  3. Prescription Safety Glasses
    Workers who wear prescription eyeglasses for general working conditions should consider obtaining prescription safety glasses
  4. Eyewash stations
    There should be at least one eyewash facility per laboratory. They may be located at sinks or at any other readily accessible area. Laboratories using strong acids or bases should have an eyewash within 20 feet of the hazard area. An eyewash station should provide a soft stream or spray of aerated water for an extended period of at least 15 minutes.

D. Respiratory Protection

  1. General Information
    The current policy and procedure at the CSB/SJU do not support the use of respirators. Where necessary, the Environmental Health and Safety office will provide respiratory protection for situations where engineering and administrative controls cannot feasibly contain a respiratory hazard. This will include hazard evaluation, respirator selection, fitting and training, maintenance, medical surveillance, and program evaluation.
  2. Procedures
    • Environmental H ealth and Safety Office should be contacted, if respirators and their use is a job requirement.  
    • The Occupational Health Clinic for each campus must certify wearers to be physically capable of wearing specified respirator. 
    • properly trained and fitted for each specific respirator. EH&S can arrange for the training and fit-testing services.

Compressed Gases

A. General Information

  1. Compressed gases in cylinders are hazardous because of the potential energy of compression and because gas may be toxic, flammable, and/or act as an asphyxiant if released in a confined space.
  2. Compressed gas cylinders must be used and stored whenever possible in accordance with distributor/ manufacture instruction or  as directed by the National Fire Protection Association, and in accordance with the Compressed Gas Association, Inc., "Handbook for Handling Compressed Gases,".

B. Toxic Gases

Below is a list of some restricted toxic gases. Written permission is required for the purchase of these highly toxic gases. Personnel must notify the department chair and Environmental Health and Safety office, of intent to work with highly toxic gases prior to the proposed purchase to allow time for necessary safety preparations including arrangements for proper disposal. Small, instead of large, cylinders of toxic gases should be purchased when possible.

Restricted Toxic Gases
Purchase and use of the following are restricted:

  • Boron trifluoride Chlorine
  • Chlorine trifluoride Dimethylamine
  • Ethylene oxide (other than 12/88 sterilizing mixtures) 
  • Fluorine
  • Hydrogen bromide (hydrobromic acid)
  • Hydrogen chloride (hydrochloric acid)
  • Hydrogen fluoride (hydrofluoric acid)
  • Hydrogen sulfide
  • Iodine pentafluoride (liquid shipped in gas-type cylinders) 
  • Methyl bromide (bromomethane)
  • Methyl chloride
  • Nitric oxide
  • Nitrogen dioxide (nitrogen tetroxide)
  • Nitrogen trioxide
  • Nitrogen chloride (nitrogen oxychloride)
  • Phosgene
  • Silicon tetrafluoride (tetrafluorosilane)
  • Sulfur dioxide

C. Flammable gases

Fire and explosive hazards can result when flammable gases such as hydrogen, acetylene, and others are used in confined spaces.

  1. If more than one cylinder of highly flammable gas is to be placed in a room, the fire department and the Environmental Health and Safety office must be notified.
  2. When cylinders of flammable gases are kept inside the building, two or more cylinders cannot be manifold together.
  3. Several instruments may be operated from one cylinder.
  4. Full reserve cylinders or empty cylinders must not be stored in the laboratory. Empty cylinders will be removed from the laboratory when the full cylinders are delivered.
  5. Adapters may be used only upon written permission of authorized and knowledgeable person.
  6. Piping must be compatible with the gas, e.g. no copper for acetylene, no plastic tubing in any high pressure portion of a system, etc.
  7. When practical, valves on flammable gas cylinders should be closed before the laboratory is vacated at the end of the work-shift or workday.
  8. If a cylinder of toxic or flammable gas is leaking, contact the security (CSB 5000) or life safety (SJU-911) or local fire department immediately. Confine, alert others and evacuate the area. Turn off any open flames if the gas is flammable.
  9. Display appropriate hazard warning signs when using flammable or toxic gases.

D. Acceptance of cylinders from vendors

  1. The contents of cylinders must be identified with decals, stencils, glued or wired-on tags, or other markings on the cylinders. Color codes alone or tags hung around the necks of the cylinders are not very reliable.
  2. The valve safety covers are in place and properly tightened
  3. Employees or vendors moving cylinders in CSB/SJU buildings must use hand trucks, carts, or dollies. Cylinders must not be dragged or rolled for distances greater than 3 feet.
  4. Compressed Gas Association standard valve assemblages must be used.

E. Storage of cylinders in holding (shipping and receiving) areas.

  1. If possible, cylinders should be stored in a separate room designed to meet NFPA standards for storage of compressed gases.
  2. Cylinders stored out of doors must be protected from the weather and tampering, by a covered and enclosed area providing safe access and adequate security.
  3. Full and empty cylinders must be clearly marked and stored separately if possible.
  4. Cylinders containing flammable gases should not be stored adjacent to oxidizers.

F. Handling and storage of compressed gas cylinders

  1. Laboratory personnel must review with the laboratory supervisor, storage, handling and hazard precautions of compressed gas cylinders prior to using compressed gases.
  2. Compressed gas cylinders must not be moved unless the protective valve cover is securely in place. The valve safety covers must be left on the cylinders until they are secured to walls, benches or stable pieces of equipment, or until non-tip bases are attached.
  3. Compressed gas cylinders must be moved on cylinder carts, hand trucks, or dollies specifically designed for this purpose. The valve safety covers must be in place and the cylinders secured to the carts during transport.
  4. Compressed gas cylinders must never be rolled a distance of greater than 3 feet. Compressed gas cylinders must never be dragged.
  5. Cylinders of compressed gas must be secured at all times so they cannot fall. They can be secured with chain or canvas straps.
  6. The main valve cylinder should be opened only as far as necessary to produce the required gas flow and closed when the gas is not required.
  7. Cylinders must be checked for leaks when received in the laboratory.
  8. Reserve cylinders must not be stored in the laboratory.
  9. Never attempt to refill empty cylinders.

G. Empty Cylinders

  1. Empty cylinders must be labeled as such and promptly removed. Generally, this marking (EMPTY or MT) should be on a large piece of adhesive or masking tape stuck on the cylinder. If the cylinder has a tag wired to the valve that identifies the contents, the bottom half of the tag may be removed to indicate an empty cylinder.
  2. A small amount of gas must be left in the cylinder and the cylinder valves must be closed to prevent contamination of the inside of the cylinder.
  3. Valve covers and the labels indicating cylinder contents must be in place, prior to removal.
  4. Cylinders without proper tags or labels must not be used. Label cylinder "contents unknown" and place in the empty stock for return to supplier.
  5. If present, empty cylinders of toxic gases must be disposed of in accordance with the hazardous waste disposal procedure.

H. Pressure regulators and needle valves

  1. Selection of regulators and needle valves
    a. The valve fittings of cylinders used to store different families of gases are specific and will only allow regulators or needle valves to be attached that are safe for use with those gases. Only pressure regulators and needle valves approved for a specific gas may be used.
    b. Cylinders must not be purchased or accepted whose fittings do not conform to standards of the National Compressed Gas Association.
  2. Use of regulators and needle valves.
    a. Threads, points, and unions must be clean; these surfaces must be inspected before connections are made. Personnel must not attempt to lubricate threads or fittings.
    b. When attaching regulators or needle valves, connections must be firmly tightened. Nonadjustable wrenches of the proper size should be used. Pliers or adjustable wrenches, which may damage the brass nuts, should not be used. Leaks at the unions between the regulators and the cylinder valves are usually due to damage to the faces of the connections.
    c. Return cylinders with damaged cylinder valve faces to the vendor.
  3. After the pressure regulator is attached to the cylinder, turn out the delivery pressure adjusting screws of the regulators until they turn freely.
  4. Slowly open the cylinder valves. Avoid standing directly in front of the regulators at this time as the pressure of the cylinders may blow the glass from the front of a faulty gauge.
  5. Cylinder valve handles should be left attached to the valves while the cylinders are in use. Cylinder valves that "stick" and do not open when the usual amount of force is applied may be damaged. Return to vendor stating on the cylinders that the valves are stuck.
  6. Pressure in full cylinders should be as indicated on the cylinders or labels. Lack of full pressure many indicate leaks at the connections between the cylinders and valve regulators, damaged regulators, or incompletely filled cylinders.
  7. Delivery lines should be connected to the low pressure outlet of the regulator valves or to the needle valves. Where low pressure lined are used, their valves should be closed and line pressure adjusted by turning the regulator delivery pressure adjusting screws until the desired pressures are shown on the delivery pressure gauges.
  8. If the gases are not to be used within a 24 hour time period, close the cylinder valves, bleed the lines, and turn back the pressure adjusting screws until they turn freely Damage to the gauges may result if pressure is left on the gauges during extended periods of non-use.

I. Leak testing

Leak testing is the use of a solution, such as a soap solution, to observe a leak under pressure by the formation of bubbles as gas escapes from the leak. Compressed gas cylinders are tested for leaks when they are filled; however, leaks have been detected after cylinders have been received.

  1. Leak testing method
    1. Cylinders should be leak tested both before and after attachment of the regulator.
    2. To test for leaks, prepare and use a soap solution of a few drops of liquid soap in a small squeeze bottle of water.
  2. Return of leaking cylinders
    1. Leaking cylinders of nontoxic, nonflammable gas may be taken to a loading dock or other place having suitable air flow.  Leaking cylinders will be returned to the vendor.
    2. Leaks from cylinders of toxic or flammable gases require immediate attention.  The area in which a leaking cylinder may require evacuation of persons in the area.
    3. Gas masks and appropriate protective clothing shall be worn when attempting to move leaking cylinders of toxic gas. 

Safe Use of Laboratory Equipment and Facilities

General Information, Rules, and Procedures

A. Laboratory Apparatus

Laboratory apparatus must be used only for its designed purpose unless appropriate safety modifications are made. Operating manuals must be consulted for detailed operating instructions for individual pieces of equipment.

B. Electrical

  1. All electrical equipment used in the laboratory must be grounded. Ground fault circuit interrupters must be used whenever equipment is in a wet environment such as a cold room.
  2. Electrical apparatus must be plugged into sockets which can be reached safely, without exposure to hazards.
  3. Electrical apparatus used in a fume hood must be plugged in outside the hood.
  4. Electrical cords must be as short as practical and must be placed in such a way that the risk of tripping or spills is minimized.
  5. Extension cords must be avoided. If unavoidable, ascertain that the extension cord is appropriate.
  6. Equipment, including electrical plugs and cords, must be kept in good repair. Electrical equipment must be unplugged before routine parts replacement or before making internal adjustments.
  7. A qualified electrician must make electrical repairs.
  8. Non-sparking electrical switches and motors are desirable in laboratory equipment to prevent combustion of flammable vapors.

C. Heating Devices

  1. Uncontrolled heat sources such as Bunsen burners and heat guns must not be used near flammable substances and must not be left unattended in the laboratory.
  2. Heating devices (i.e. steam baths) which have an inherent cutoff point are safer than those which do not.
  3. Hot plates, heating mantles, and other heaters must have enclosed elements and controls with a thermal shut-off safety device.

D. Cryogenic Liquids

Cryogenic liquids are gases that have been transformed into extremely cold refrigerated liquids which are stored at temperatures below -130oF (-90oC). They are normally stored at low pressures in specially constructed, multi-walled, vacuum-insulated containers.

  1. Hazards
    The potential hazards that accompany cryogenic liquids may result from:
    1. Extreme cold which can freeze human tissue on contact, and which can also cause other materials like carbon steel, plastics, and rubber to become brittle.
    2. Extreme pressure which can result from rapid vaporization of the refrigerated liquid due to rising temperature from leakage of heat into the cryogenic container or systems.
    3. Asphyxiation due to displacement of air by escaping liquid and the resultant rapidly expanding gas (in the case of inert gasses)
  2. Personnel Safety
    Because of the potential hazards resulting from the extremely low temperatures of cryogenic liquids, all personnel handling them must be properly informed of the use of specialized equipment designed for the storage, transfer, and handling of these products.
    Heavy leather protective gloves, aprons, and eye protection must be worn to prevent possible contact with the extremely cold surfaces of uninsulated transfer connections, valves, and other equipment, or from the cold liquid or boil-off vapors which may result from spilled or splashed liquid.
    Any transfer operations involving open containers such as dewars must be conducted slowly to minimize boiling and splashing of the cryogenic liquid, and such operations must be conducted only in well-ventilated areas to prevent the possible accumulation of inert gas which can replace the oxygen in the atmosphere and cause asphyxiation.

E. Centrifuges

  1. Each centrifuge operator must be familiar with the proper operating procedures of the centrifuge including balancing loads, selection of proper rotor, head, cups, and tubes, and use of accessory equipment. Consult the centrifuge operating manual, and/or supervisor for information and/or assistance.
  2. Centrifugation presents a physical hazard in the event of mechanical disruption. Aerosols and droplets may also be generated.
  3. The centrifuge operator is responsible for the condition of the machine at the end of each procedure.
  4. Operating procedures for each centrifuge must be established by the supervisor in accordance with the procedures outlines in the operating manual, guidelines for centrifugation of infectious agents, chemical hazards and the location of centrifuge.
  5. Rooms where live etiologic agents are centrifuged should be identified with an appropriate hazard warning sign.

Centrifuge tubes

  1. Plastic centrifuge tubes should be used whenever possible to minimize breakage.
  2. All centrifuge tubes should be inspected prior to use. Broken, cracked, or damaged tubes should be discarded.
  3. Refer to operating manual for selection of appropriate tubes, carrier cups, and rotors.
  4. Capped centrifuged should be used whenever possible.

Carrier cups and rotors

  1. Consult operating manual for proper selection and use of carrier cups and rotors. Do not exceed recommended speeds.
  2. Keep centrifuge cups and rotors clean to prevent corrosion. Consult operating manual for instructions.

F. Lasers

Laser-containing equipment has the potential for causing eye and skin damage. Other hazards associated with this type of equipment include exposures to cryogenic coolants and accidental electrocutions.


Lasers are classified according to the American National Standards Institute's (ANSI) "Safe Use of Lasers" laser classification scheme (ANSI Z136.1-1992). The classification scheme is used to describe the potential hazard of a laser or laser system based upon its optical emission intensity. The higher the classification number, the greater the potential hazard.

  1. Class I 
    denotes exempt lasers or laser systems that cannot, under normal operating conditions, produce a hazard.
  2. Class II 
    denotes low power visible lasers or laser systems which, because of the normal human aversion responses, do not normally present a hazard, but may present potential for hazard if viewed directly for an extended period of time.
  3. Class IIa 
    denotes low power visible lasers or laser systems that are not intended for prolonged viewing, and under normal operating conditions will not produce a hazard if viewed directly for period not exceeding 1,000 seconds.
  4. Class IIIa 
    denotes lasers or laser systems that normally would not produce a hazard if viewed for only momentary periods with the naked eye. They may present a hazard if viewed using collecting optics.
  5. Class IIIb 
    denotes lasers or laser systems that can produce a hazard if viewed directly. This includes intrabeam viewing of specular reflections.
    Except for the higher power Class IIIb lasers, Class III laser will not produce a hazardous diffuse reflection, that is one where the reflected radiant energy follows Lambert's Law where, in essence, the radiation is reflected over a wide angular range.
  6. Class IV  
    denotes lasers or laser systems that can produce a hazard not only from direct or specular reflections, but also from a diffuse reflection. These lasers may also produce fire and skin hazards.

Laser classes must be provided by manufacturer for lasers sold after August 1976.

Safety Procedures:

  1. Safety procedures for each laser application will be determined primarily by the purchasing department.
  2. In order to determine the appropriate laser safety information, procedures, and approval for use, the following information is necessary:
    • the laser classification,
    • the environment in which the laser is to be used, and
    • the personnel operating, and those in the vicinity of, the laser equipment.

G. Ultraviolet (UV) lights

  1. General Information

    Ultraviolet radiation includes that portions of the radiant energy spectrum between visible light and X-rays (approximately 3900 to 136 angstrom units). Under certain conditions, including radiation intensity and exposure time, UV radiations may kill certain types of microorganisms, its greatest effectiveness being against vegetative forms. UV light is not a sterilizing agent except in certain exceptional circumstances. It is used only to reduce the number of microorganisms on surfaces and in the air. Factors such as lamp age and just accumulation will contribute to decreased efficiency.
  2. Radiation Exposure
    a. The eyes and skin should not be exposed to direct or strongly reflected UV radiation. The effect of radiation overexposure is determined by such factors as dosage, wave length, portion of the body exposed, and the sensitivity of the individual.
    b. Overexposure of the eyes will result in a painful inflammation of the conjunctiva, cornea, and iris. Symptoms will develop 3-9 hours following exposure. There is an unpleasant foreign body sensation accompanied by lacrimation. The symptoms usually disappear in a day or two.
  3. Procedures
    1. A hazard warning sign must be affixed on the doors of the laboratories, animal rooms, etc., which have ultraviolet light installations.
    2. Adequate eye and skin protection must be worn when working in an irradiated area.  Safety glasses with side shields or goggles with solid side pieces mus be worn.  Skin protection is afforded by face shields, caps, gloves, gowns, etc.
    3. UV lamp surfaces shold be cleaned as often as necessary to maximize output.
    4. UV lamps used as space and surface sanitizers should be checked regularly and replaced according to the manufacturer's recommendations.
    5. Use manufacturers information concerning UV lamp use, cleaning, testing or installation.

H. Microwave ovens

Food for human consumption may not be heated in microwave ovens unless the oven is used solely for that purpose.

  1. When melting agar the following precautions must be taken:
    1. Explosions may occur when melting agar using a microwave oven.
    2. Caps on screw-cap bottles must be completely loosened before the bottles are heating in the microwave oven.
    3. A long-sleeve laboratory coat must be worn when heating agar in a microwave oven.
    4. Heat-resistant gloves must be worn to prevent burns and protect the hands in case of an explosion.
    5. Face-shields must be used when handling microwave-heated materials.

I. Autoclaves

  1. Autoclaves must be operated in accordance with the manufacturer's and laboratory safety manual's instructions.
  2. Operating instructions and emergency shutdown procedures must be posted on or immediately adjacent to the autoclave.
  3. Responsibility for operation and routine care must be assigned to trained personnel.
  4. Eye protection, heat-resistant gloves, and aprons must be worn when loading and unloading a hot autoclave. Opening doors too soon after a run is finished may blow hot fluids and noxious vapors on the operator.
  5. Need something about correct loading procedures.
  6. Records of each run must be kept.
  7. Autoclaves must be checked regularly to assure decontamination effectiveness.
  8. Potentially contaminated autoclave condensate must be treated before discarding. Filters should be installed when needed.

Removal or Servicing of Laboratory Safety Equipment

A. Removal of Laboratory Equipment

  • Laboratory equipment should be labeled to be free from dangerous chemicals or infectious organisms prior to removal from a laboratory.
  • Consult with the laboratory supervisor, or written standard operating procedures for decontamination procedures.
  • Service personnel must also be informed of the biosafety level of the laboratory and any necessary precautions to be taken while working in the laboratory.


Although laboratory equipment and materials should not be stored in corridors, the acute space shortage in some laboratories has necessitated the limited use of laboratory corridors to store some non-hazardous items. Storage of furniture, equipment, or materials is not permitted in office corridors.

A. Policy

Corridors must provide a clear evacuation route in case of emergencies and permit responding emergency personnel unhampered access to all areas.

B. Rules

  1. Permission to permanently place any item in a laboratory corridor must be obtained from the Physical Plant and Environmental Health and Safety.
  2. Permission will not be granted unless the need is justified. Lack of space due to poor planning, storage of unused equipment, or inappropriate use of laboratory space does not constitute a justification.

C. Criteria for placement of items in corridors

  1. A minimum clear corridor width of 44 inches must be maintained at all times.
  2. All items must be placed on one side only and, where feasible, the side utilized is the same throughout. Corridors which have alcoves may have equipment on both sides, provided the 44-inch clearance is maintained and the equipment in the alcoves does not extend beyond the boundary of the alcove.
  3. A minimum of 18 inches will be maintained between equipment and the latch side of doors along the corridor, and a minimum of 12 inches will be maintained on the hinge side.
  4. Equipment must not extend beyond the wall at a corner.
  5. Electrically operated equipment must be connected to permanently mounted electrical receptacles. No extension cord may be used.
  6. Equipment must not obstruct exit signs, safety equipment such as fire hydrants, hoses, or extinguisher, alarm panel boxes, bulletin boards containing emergency exit route information, electrical panel boxes, etc.

Decontamination and Disposal of Laboratory Wastes

A. Policy

Infectious and/or toxic materials must be disposed of in a manner that prevents environmental contamination and protect laboratory personnel, maintenance, service, and housekeeping staff from exposure to infectious or toxic materials in the course of their work.

B. Rules

  1. All biohazardous materials must be secured in an appropriately marked container (refrigerator, freezer, incubator, etc.) or decontaminated at the end of each workday.
  2. All hazardous chemical wastes must be disposed of in accordance with established CSB/SJU procedures. The department safety committee chair, laboratory coordinator/stock manager or Environmental Health and Safety must be contacted for disposal of these wastes.
  3. No laboratory glassware, plastics, etc. may be discarded in a trash receptacle serviced by custodial personnel.

C. Decontamination of Reusable Items

  1. Reusable laboratory wares contaminated with biological or chemical agents must be decontaminated or neutralized prior to reprocessing and recycling.
  2. Reusable items must be separated from non-reusable disposable items and sharps.
  3. All reusable laboratory wares must be discarded in appropriately identified containers or sinks. The containers destined for autoclave disinfection must have lids securely fastened with autoclave tape or other department established coding procedure.
  4. When a container is ready for disposal/decontamination, secure lid and place a room or any required identification sticker on the container. Identify contents as "Reusable" or "Disposal".
  5. Follow department procedures or schedules for the disposal/ decontamination station.

D. Decontamination of Disposable Laboratory Waste

  1. All disposable laboratory ware must be autoclaved prior to disposal, except for items contaminated with hazardous chemicals. These items require special treatment; consult laboratory coordinator/manager or EH&S if you have questions.
  2. Soft, dry items such as disposable gowns, gloves, masks, paper, plastic etc (NO HARD PLASTIC, NO PLASTIC LABWARE, NO GLASS) may be placed in autoclave bags and autoclaved without the use of puncture resistant containers. ANYTHING THAT COULD PUNCTURE A BAG MUST BE PLACED IN A PUNCTURE RESISTANT CONTAINER.
  3. All other disposable labware, including cultures, media, microtitration trays, pipettes etc. must be placed in puncture resistant autoclave containers.
  4. Before autoclaving, carefully add approximately 250-500 ml of water (or dilute germicidal solution. Some germicides may produce fumes or objectionable odors. Do not use Bleach!). AVOID SPLASHING.
  5. Fold ends of bag, but do not tie. This will allow steam penetration.
  6. Replace container lid. Place proper labels and autoclave tape on the container.
  7. Autoclave bags should not be used for reusable items such as glassware, or glass syringes. Place these items directly in a puncture resistant autoclave container covered with a lid.
  8. Supply of autoclave bags will be kept in each autoclave room or with other laboratory safety supplies.

E. Disposal of Needles and Sharps

Needles, scalpel blades and other sharps that can easily puncture the skin should be handled with extreme caution.

  1. Used, disposable needles and other sharps must be placed in a rigid puncture-resistant disposable container with a lid.
  2. Disposable syringes with attached needles must be disposed of as one unit without separation of the needle from the syringe.
  3. Needles must not be resheathed, bent, broken, or cut.
  4. Adapters used with evacuated tubes must not be reused. Discard needles and adapter as a unit; do not remove needle from adapter.
  5. Discard containers for sharps must be clearly labeled as such. Container must also be identified with users room number. Unidentified containers may not be processed.

F. Disposal of paper wastes from potentially infectious laboratory procedures 

Many laboratory items are disposable and may be wrapped with plastic or paper, i.e. pipettes, gloves, etc. To avoid disposal of potentially contaminated paper products in the waste receptacles serviced by janitorial personnel, the following procedure is recommended.

  1. Place a biohazard discard bag on a stand next to the workstation
  2. Discard all paper wrappings into this bag unless the paper is obviously contaminated. Contaminated paper products should be discarded in the discard container placed in a Biological Safety Cabinet.
  3. When the bag is full, securely close the bag opening with a "tie".
  4. Place a room or any identification sticker on the bag.
  5. Dispose of the bag as described in laboratory standard operating procedures or bloodborne exposure control plan.
  6. Do not place other laboratory items in the bag.

G. Disposal of Hazardous Chemical Wastes

Go to the Chemical Hygiene Plan for further information or contact EH&S/academic safety officer.

H. Disposal of Potentially Infectious Biological Waste Materials

Go to the Blood-borne Pathogen Exposure Plan for further information.