OhASIS HOME | Biosafety Information | Safety Manuals

---

General Laboratory Health and Safety

---

09–00–	10 Introduction 20 Responsibilities 30 Project Review/Approval Mechanism 40 Identification and Control of Hazardous Areas 50 Hazard Containment 60 Control of Air Flow in Laboratory Areas 70 Safe Work Practices 80 Safe Use of Laboratory Equipment and Facilities 90 Decontamination and Disposal of Laboratory Wastes

09-00-10 INTRODUCTION

The laboratories of CDC require hazard containment of biological, radiological, chemical and physical hazards. Policies and procedures relevant to most laboratory situations will be defined in this chapter. Policies and procedures relevant to a specific situation or program(e.g. radiation, chemical hygiene blood-borne pathogens) will be defined in separate chapters.

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

09-00-20 RESPONSIBILITIES

1. Director, CDC
   The Director, CDC is responsible for enforcing and regulating the laboratory safety program.
2. Office of Health and Safety
   The Office of Health and Safety provides staff support for the Center Director in all matters relating to safety.
3. C/I/O Director
   The Director of each C/I/O is responsible for ensuring that all laboratory activities under his or her control are conducted in a manner that presents the least possible hazard to employees and the surrounding community. The Director must ensure that all safety policies and regulations are enforced and that necessary safety equipment is available in the laboratory.
4. Line Supervisors
   The first-line supervisor has the primary responsibility for the health and safety of all program personnel under his/her jurisdiction including CDC employees, guest scientists, students and visitors. The supervisor's 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;
   • In conjunction with EHSC, selection of appropriate preventive medical practices, serologic monitoring, and immunization protocols, and inform program personnel of the rationale for their selection;
   • 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 OHS, establishing and periodically reviewing emergency procedures for accidental spills and any overt exposure to hazardous substances;
   • Arranging for immediate medical attention for injured personnel and reporting of incidents as required;
   • Complying with all policies and procedures as outlined in this manual.
5. Individual Employees
   Each employee's responsibilities include:
   • Complying with all CDC/ATSDR 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.;
   • Reporting unsafe conditions or practices to the line supervisor or OHS;
   • Reporting all incidents resulting in injury or exposure to hazardous agents to the line supervisor or OHS.

09-00-30 PROJECTS REVIEW/APPROVAL MECHANISMS

1. Scope
   All projects and activities involving biological or radiological hazards at CDC are subject to review and approval by OHS and/or relevant safety and health committees. The purposes of such a review are:
   • To identify hazards and assess the risks associated with the project or activity;
   • To evaluate the adequacy of safety procedures, the facilities, and the equipment; and
   • To determine the need for and course of immunization or other preventive medical measures.
2. Biological Hazards/Toxic Materials
   Before beginning any project involving the use of hazardous biological or toxic agents, the Form CDC 0.838, "Notice of Intent to Work With a Hazardous Biological Agent or Toxic Material" must be completed and forwarded to OHS through the respective C/I/O. Form CDC 0.838 must be completed when:
   • An existing technique is to be modified and the investigator believes that the modification may increase risk to laboratory personnel or animal caretakers;
   • An antigen, whose risks are well understood, is to be highly concentrated with possible increased risks.
   • An infectious agent is to be used which required immunization of personnel prior to onset of work, or
   • A new technique, agent and/or procedure.

   
   

   1. Procedure
   2. The investigator should contact the Office of Health and Safety to determine whether Form CDC 0.838 will be necessary for the proposed work.
   3. The investigator should submit one copy of the completed form through administrative channels to the Office of Health and Safety.
   4. The Office of Health and Safety will contact supervisors of all personnel who will be at risk if immunizations are required. The investigator should allow 4 weeks for immunizations to be accomplished.
   5. Upon receipt of Form CDC 0.838, the Office of Health and Safety will evaluate the project protocol, equipment, work space, and other pertinent information for safety. The investigator will be advised concerning the acceptability of the protocol and any modifications, additions, etc. required.
   6. The Office of Health and Safety will issue the investigator a clearance to begin work when all work hazards are satisfactorily controlled.
   7. The Office of Health and Safety will notify other individuals as appropriate of the proposed project.
3. Radioisotopes

   Projects that involve radioisotopes must be reviewed and approved by the Radiation Safety Committee (See Chapter 12 of this manual).

09-00-40 IDENTIFICATION AND CONTROL OF HAZARDOUS AREAS

A. Controlled Access

Certain areas within CDC facilities have been designated restricted and access is controlled by card-key access. To prevent unauthorized personnel from entering restricted areas, a card key, issued to each person officially needing access to a controlled area, permits entry.

Employees should make card requisition to the Office of Program Support (OPS), Physical Security Activity, using Form CDC 0.834, "Cardkey Request." Employees requesting access into laboratory areas must verify they have a baseline serum specimen stored in the Serum Bank.

Supervisors must approve all requests. Cards are issued by OPS and are accountable items which must be returned to CDC on reassignment or termination.

B. Visitors in Laboratory Areas

1. Policy

   a.

   Children under 12 years of age are not permitted into any laboratory or animal holding area at any time.

   b.

   Each laboratory supervisor is responsible for the safety of adult visitors to his or her laboratory, including ensuring that immunization, training, issuance of personal protective equipment, paper work completion, and other requirements have been met.

2. Rules and Procedures

   a.

   Maintenance personnel must not be left unattended without the prior approval of the laboratory supervisor.

   b.

   Doors to restricted areas must not be propped open to allow visitor access.

   c.

   Visitors to the Clifton Road or Chamblee facilities, must obtain an identification badge from the security guard.

1. C. Hazard Warning Signs and Labels
2. Hazard Categories
   
   Hazard identification signage has four distinct categories:

   NOTICE –

   states a policy related to safety of personnel or protection or property but is not for use with a physical hazard.

   CAUTION –

   indicates a potentially hazardous situation that, if not avoided, may result in minor or moderate injury.

   WARNING –

   indicates a potentially hazardous situation that, if not avoided, will result in death or serious injury.

   DANGER –

   indicates an imminently hazardous situation that, if not avoided, will result in death or serious injury.

3. 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, supervisors, and lab workers; 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 ares 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.
4. Posting of Hazard Signs and Labels

   The laboratory supervisor is responsible for posting hazard warning signs as necessary and in compliance with the requirements for each type of hazard encountered. Information on proper types of signs and specific requirements for signage should be directed to the Office of Health and Safety.

5. Rules and Procedures

   a.

   Signs must be posted only while a hazard exists and must be removed as soon as the source of danger is removed.

   b.

   Hazard warning signs must show the name(s) of the hazard(s) and the investigator, his/her alternate, with their home telephone numbers.

   c.

   The investigator named on the hazard sign will determine when visitors can be allowed in the laboratory.

   d.

   Signs that are to be used permanently must be posted in permanent frames. Contact the Office of Health and Safety or the Office of Engineering Services for assistance in installation.

   e.

   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.

   f.

   Hazard warning signs are supplied by the Office of Health and Safety.

09-00-50 HAZARD CONTAINMENT

A. General

Facility design, safety equipment, and practices for containing laboratory hazards vary according to the nature to 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 investigator and organization based on experience gained from work conditions, and on relevant guidelines and regulations established by safety experts, committees within and outside of CDC, and regulatory and granting agencies.

B. Types of Hazards

• Biological Hazards (Reference Chapter 10)
• Chemical Hazards (Reference Chapter 11)
• Radioactive Hazards (Reference Chapter 12)

C. Ventilation controls

Biological Safety Cabinets (BSCs) and fume hoods are primary containment devices designed to protect workers from exposure to hazards by physical barriers and by directional airflow carrying hazards away from the workers.

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 airstream at an efficiency of 99.97 or greater.
2. Cabinet classes

   a.

   Class I cabinets provide partial personnel protection and no product protection and are suitable for handling low-to-moderate risk biohazardous aerosols when product protection is not essential. Small amounts of toxic or flammable chemicals may be used as air is not recirculated. 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 recirculate 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.

3. Clean Air Cabinets
   
   Clean air cabinets, also called clean benches, sterility hoods, laminar flow hoods or clean air stations, 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 clean air stations because these cabinets do 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.
4. 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 do not operate outside normal working hours.
5. 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.

09-00-60 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 air flow. 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. Doors to autoclave rooms must also be kept closed in order to control odors as well as maintain air balance in the laboratory corridors.

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 Engineering Services Office at each facility.

Laboratorians must not continue to work after regular operating hours of air-handling systems unless prior arrangements have been made with the Engineering Services Office to maintain ventilation in the area. Form CDC 0.932, "Requesting the use of heating, ventilation, and air conditioning systems after office hours-Clifton Road and Chamblee Facilities" or appropriate facility form must be completed.

C. Ventilation Failure

In the event of failure of the laboratory ventilation system:

• Immediately stop working with hazardous agents.
• Contain the hazards.
• Leave the laboratory.
• Notify the Office of Health and Safety (639-3235) and the Engineering Services Office (639-3216).

09-00-70 SAFE WORK PRACTICES

A. Policy

The following rules and procedures apply to all CDC laboratories. Additional information on chemical, radiological and biological methods, procedures, and hazards are found in Chapters 10, 11, and 12 of this manual.

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 pans distributed by the Laboratory Services Section, Scientific Resources Program, NCID; disposable and nondisposable items are to be placed in separate containers. This includes vacutainer holders (complete with attached needle) which are considered a disposable item.
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 not be done in laboratory areas where these materials could become contaminated with hazardous agents.

09-00-71 Personal Protective Equipment

A. Laboratory Clothing

1. Employees must wear protective clothing appropriate for agents handled in the laboratory. (Reference Chapter 10, 11, and 12; CDC/NIH publication "Biosafety in Microbiological and Biomedical Laboratories"; and "Prudent Practices for Handling Chemicals in Laboratories", 1981)
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. Laboratory coats are not permitted outside of 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, traumatic injury, and barriers to skin, are available.
2. Proper selection of gloves is important. The Office of Health and Safety compiles information on types of gloves and can provide advice on those best suited for specific purposes.
3. Gloves must 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

1. 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.).
2. 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.
3. 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. The Office of Health and Safety will assist in the choice of suitable protective equipment and will provide protective eye and face equipment.
4. 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.
5. Prescription Safety Glasses
   
   Workers who wear prescription eyeglasses for general working conditions should obtain prescription safety glasses. Supervisors must contact OHS to obtain the appropriate forms for requesting prescription safety glasses.
6. 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 time (15 minutes).

D. Respiratory Protection

1. General Information
   
   The Office of Health and Safety provides respiratory protection for situations where engineering and administrative controls cannot feasibly contain a respiratory hazard. This program includes hazard evaluation, respirator selection, fitting and training, maintenance, medical surveillance, and program evaluation.
2. Procedures

   a.

   Respirators and their use must be approved by the Office of Health and Safety.

   b.

   The Occupational Health Clinic, or equivalent, must certify wearers to be physically capable of wearing specified respirator.

   c.

   Respirator wearers must be properly trained and fitted for each specific respirator. OHS provides training and fit-testing services.

   d.

   Respiratory protection in the form of air-supplied suits is required for biohazard control in Biosafety Level 4 laboratories for work not contained in cabinet-like glove boxes, for some work with chemical hazards, and during hazard clean up where appropriate.

09-00-72 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. The Office of Health and Safety has information available on most of the gases likely to be used in CDC laboratories.
3. Compressed gas cylinders must be used and stored whenever possible as directed by the National Fire Protection Association, and in accordance with the Compressed Gas Association, Inc., "Handbook for Handling Compressed Gases," 1990.

B. Toxic Gases

Highly toxic gases may be purchased and used only upon written permission of the Office Health and Safety. Personnel must notify the Office of Health and Safety, through the laboratory supervisor, 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.

1. 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
2. Toxic gases - Purchasing requirements

   a.

   Personnel planning to purchase toxic gas(es) must notify the Office of Health and Safety, through the laboratory supervisor, of intent to work with highly toxic gas(es) prior to the proposed purchase to allow time for necessary safety preparations including arrangements for proper disposal and instructions concerning the availability and use of respirators.

   b.

   The Office of Health and Safety will authorize the purchase of the gas(es). Notice will be sent to the investigator through the supervisor in charge of the laboratory after determining that the gas can be used safely.

   c.

   Clearance to use toxic gas(es) should be requested well in advance of the proposed use as some of these gases are extremely toxic and may require isolated laboratory space and equipment not immediately available.

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, written permission must be obtained from the Office of Health and Safety.
2. When cylinders of flammable gases are kept inside the building, two or more cylinders cannot be manifolded 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. Cylinder size will be limited to 200 cubic feet.
6. Adapters may be used only upon written permission of the Office of Health and Safety.
7. 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.
8. When practical, valves on flammable gas cylinders should be closed before the laboratory is vacated at the end of the workday.
9. If a cylinder of toxic or flammable gas is leaking, contact the Office of Health and Safety, or local fire department immediately. Evacuate the area. Turn off any open flames if the gas is flammable.
10. 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 acceptable.
2. Cylinders must not be accepted from the vendor unless the valve safety covers are in place and properly tightened
3. Vendors moving cylinders in CDC 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. Cylinders should be stored outside or 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 receive training from the laboratory supervisor of Office of Health and Safety on storage, handling and hazard precautions 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. Laboratories in which toxic gases are used must be equipped with proper gas masks and respirators. Contact the Office of Health and Safety to determine the need for protective devices.
10. 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. Check with respective C/I/O or OHS for cylinder removal procedure.
5. Return empty cylinders promptly. Demurrage charges continue until cylinders are returned to the supplier.
6. Cylinders without proper tags or labels must not be used. Label cylinder "contents unknown" and place in the empty stock for return to supplier.
7. Empty cylinders of toxic gases must be disposed of with the assistance of the Office of Health and Safety.

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. The Office of Health and Safety can provide information on appropriate wrenches.

   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 nonuse.

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

   a.

   Cylinders should be leak tested both before and after attachment of the regulator.

   b.

   To test for leaks, prepare a soap solution of a few drops of liquid soap in a small squeeze bottle of water.

2. Return of leaking cylinders

   a.

   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.

   b.

   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. Contact the Office of Health and Safety to obtain assistance.

   c.

   Gas masks and appropriate protective clothing must be worn when attempting to move leaking cylinders of toxic gas.

09-00-80 SAFE USE OF LABORATORY EQUIPMENT AND FACILITIES

09-90-81 General information, Rules, and Procedures

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

B. Electrical

1. All electrical equipment used in the laboratory must be grounded. Ground fault circuitt 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. Consult the Engineering Services Office or the Office of Office of Health and Safety for information.
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:

   a.

   Extreme cold which can freeze human tissue on contact, and which can also cause embrittle-ment of carbon steel, plastics, and rubber.

   b.

   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.

   c.

   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 trained in the suse of specialized equipment designed for the storage, transfer, and handling of these products.
   
   Heavy leather protective gloves, safety shoes, aprons, and eye protection must be worn to prevent possible contact with the extremely cold surfaces of uninsulated piping, 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 instructed on 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, supervisor, and/or OHS 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. 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/or radioactive materials, and the location of centrifuge.
5. Rooms where live etiologic agents are centrifuged should be identified with an appropriate hazard warning sign (reference 09-00-40-C).
6. Centrifuge tubes

   a.

   Plastic centrifuge tubes should be used whenever possible to minimize breakage.

   b.

   Tubes to be used in angle-head centrifuges must never be filled to the point that liquid is in contact with the lip of the tube when it is placed in the rotor, even though the meniscus will be vertical during rotation. When the tube lip is wetted, high G forces drive the liquid past the cap seal and over the outside of the tube.

   c.

   Nitrocellulose tubes should only be used when clear, without discoloration, and flexible. It is advisable to purchase small lots several times a year rather than one large lot. Storage at 4oC extends shelf life. Nitrocellulose tubes must not be used in angle-head centrifuges. Refer to Chapter 10 of this manual for disposal instructions.

   d.

   All centrifuge tubes should be inspected prior to use. Broken, cracked, or damaged tubes should be discarded.

   e.

   Refer to operating manual for selection of appropriate tubes, carrier cups, and rotors.

   f.

   Capped centrifuged should be used whenever possible.

7. Carrier cups and rotors

   a.

   Consult operating manual for proper selection and use of carrier cups and rotors. Do not exceed recommended speeds.

   b.

   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.

1. Classification
   
   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.

   a.

   Class I denotes exempt lasers or laser systems that cannot, under normal operating conditions, produce a hazard.

   b.

   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.

   c.

   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.

   d.

   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.

   e.

   Class IIIb denotes lasers or laser systems that can produce a hazard if viewed directly. This includes intrabeam viewing of specular reflections.

   f.

   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.

   g.

   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.

   h.

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

2. Safety Procedures

   a.

   Safety procedures for each laser application will be determined by the OHS.

   b.

   To apply and obtain appropriate laser safety information, procedures, and approval for use submit a memo to OHS, Chemical and Physical Hazards Branch (F-05) listing the following information:

   • 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.

   c.

   Exposure to the skill will produce erythema (reddening) 1-8 hours following exposure.

3. Rules and Procedures

   a.

   A hazard warning sign must be affixed on the doors of laboratories, animal rooms, etc. which have ultraviolet light installations.

   b.

   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 must be worn. Skin protection is afforded by face shields, caps, gloves, gowns, etc.

   c.

   UV lamp surfaces should be cleaned as often as necessary to maximize output.

   d.

   UV lamps used as space and surface sanitizers should be checked regularly and replaced according to the manufacturer's recommendations.

   e.

   Consult with the OHS for 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:

   a.

   Explosions may occur when melting agar using a microwave oven.

   b.

   Caps on screw-cap bottles must be completely loosened before the bottles are heating in the microwave oven.

   c.

   A long-sleeve laboratory coat must be worn when heating agar in a microwave oven.

   d.

   Heat-resistant gloves must be worn to prevent burns and protect the hands in case of an explosion.

   e.

   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 monthly to assure decontamination effectiveness. Contact the Office of Health and Safety for assistance.
8. Potentially contaminated autoclave condensate must be treated before discarding. Filters should be installed when needed.

09-00-92 Removal or Servicing of Laboratory Equipment

A. Removal of Laboratory Equipment

• Laboratory equipment must be certified to be free from dangerous chemicals or infectious organisms prior to removal from a laboratory.
• Form CDC 0.593 must be completed and affixed to any equipment that is to be removed from the laboratory for maintenance, repair, transfer, surplus, or other purpose.
• Consult with the laboratory supervisor, standard operating procedures, or the Office Health and Safety for decontamination procedures.

B. On-Site Servicing of Laboratory Equipment

• Laboratory equipment must be certified to be free from dangerous chemical or infectious organisms prior to on site servicing.
• Form CDC 0.593 must be completed and affixed to any equipment prior to servicing. The form must be removed when the equipment is returned to use. Copies of the form are available:
  • At each of the maintenance and repair shops,
  • By telephone request to Engineering Services Office (Atlanta locations),
  • From the Office of Health and Safety,
  • From the collateral duty safety inspector for facilities other than at the Clifton Road facility.
• Consult with the laboratory supervisor, standard operating procedures, or the Office of health and Safety 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.
• Biosafety Level 3 organisms should not be handled when service personnel are in the laboratory to minimize potential exposure to service personnel.
• Service personnel must not be left alone in a laboratory without approval from the laboratory supervisor.
• Service personnel may also ask laboratory personnel to sign a waiver stating that the piece of equipment has been appropriately decontaminated.

09-00-93 Corridors

The CDC Corridor Policy is currently being revised. The information presented below reflects the old policy. The new Corridor Policy will be included in this section when it is adopted. 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 Office of Health and Safety. This does not include empty laboratory carts or racks for laboratory coats.
2. Permission may be granted to place the following items in the corridor:
   • Freezers and refrigerators, provided they do not contain Biosafety Level 3 or 4 infectious agents, hazardous chemicals, or radioactive materials.
   • Storage cabinets or racks for laboratory and/or office supplies.
   • Table for break areas.
3. 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.
4. The following is prohibited:
   • Storage of hazardous chemicals (flammable, explosive, toxic, corrosive, radioactive, etc.).
   • Storage of Biological Safety Level 3 and/or 4 infections agents.
   • Equipment which presents physical or electrical hazards.
   • Incubators used to process infectious agents.
   • Cylinders of hazardous compressed gas.
   • Laboratory cart(s) containing infectious wastes or discard pans.
   • Animals or animal carcasses.

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.

09-00-90 DECONTAMINATION AND DISPOSAL OF LABORATORY WASTES

A. Policy

Infectious and/or toxic materials must be disposed of in a manner that prevents environmental contamination in communities where CDC facilities are located and protects laboratorians and 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 radioactive and hazardous chemical wastes must be disposed of in accordance with established CDC procedures. The Office of 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 janitorial 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. This may be done on site in the laboratory or at a central location. Consult the laboratory supervisor, Office of Health and Safety, or Scientific Resources Program (SRP), National Center for Infectious Diseases (NCID) for assistance.
2. Reusable items must be separated from nonreusable disposable items and sharps.
3. Unless otherwise specified, all reusable laboratory wares must be discarded in the pans provided by SRP, NCID. The pans must have lids securely fastened with autoclave tape.
4. All pans collected by SRP, NCID will be autoclaved.
5. Add one inch of water to pan. Place reusable items in pan. Items must fit within the pan so that a lid may be securely attached with tape. If items are too large for pan, contact OSS for assistance.
6. When pan is ready for disposal/decontamination, secure lid and place a room identification sticker on pan. Unidentified pans will not be processed. Identify contents as "Reusable".
7. Transport pans, using a cart, to disposal/ decontamination station. Follow posted procedures; procedures may differ by location.

D. Decontamination of Disposable Laboratory Waste

1. All disposable laboratory ware must be autoclaved prior to disposal, except for items contaminated with hazardous chemicals or radioactive substances. These items require special treatment; consult OHS if you have questions.
2. Soft, dry items such as disposable gowns, gloves, masks, paper, plastic backed "diapers", etc (NO HARD PLASTIC, NO PLASTIC LABWARE, NO GLASS) may be placed in clear autoclave bags and autoclaved without pans. Prior to closing the bag, add water (about 500 ml), tie the bag loosely with autoclave tape and label with Building and Room number. ANYTHING THAT COULD PUNCTURE A BAG MUST BE PLACED IN A PAN.
3. All other disposable labware, including cultures, media, microtitration trays, pipettes etc. must be placed in pans lined with clear autoclave bags. Several sizes of bags are available*, however some bags do not fit readily and must be trimmed or folded outside the pan.
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 pan lid. Place proper labels and autoclave tape on end of pan.
7. Autoclave bags should not be used for reusable items such as glassware, or glass syringes. Place these items directly in a pan and cover with a pan lid. Bags sometimes melt, ruining reusable glassware.
8. Laboratory Services Section will keep a supply of autoclave bags in each autoclave room at the Clifton Rd., Lawrenceville and Chamblee Facilities. Additional bags can be obtained from Laboratory Services Section Stockroom (639-3202).

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 will not be processed.

F. Disposal of paper wastes from BSL 2 and 3 laboratories

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 BSC.
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 the BSC.
3. When the bag is full, securely close the bag opening with a "tie".
4. Place a room identification sticker on the bag.
5. Dispose of the bag as described in laboratory standard operating procedures.
6. Do not place other laboratory items in the bag.

G. Disposal of Hazardous Chemical Wastes

Go to the Chemical Safety Manual for further information.

H. Disposal of Radioactive Waste Materials

Go to the Radiation Safety Manual for further information.

Health and Safety Manual Contents

---

Office of Health and Safety, Centers for Disease Control and Prevention, 1600 Clifton Road N.E., Mail Stop F05 Atlanta, Georgia 30333, USA Last Modified: 1/2/97
Send us your Comments.