A comprehensive general laboratory safety program encompasses all aspects of daily laboratory operations, including engineering controls, personal protective equipment, work practice controls, transport and shipping of specimens, and waste disposal.
Throughout this article, the phrase “the laboratory needs to” explains an action directly related to fulfilling requirements of international, national, and accreditation organizations. The phrase “the laboratory should” describes a recommendation provided in laboratory literature, a statement of good laboratory practice, or a suggestion for how to meet a requirement.
Engineering controls
The biological safety cabinet (BSC) is the principal safety device used to minimize exposure to infectious aerosols generated in the clinical laboratory. Procedures with a potential for generating infectious aerosols should be conducted within a BSC. These may include centrifuging, pipetting, grinding, mixing, shaking, and opening containers. BSCs should also be used when working with high concentrations or large volumes of infectious agents; when the natural route of transmission of the agent is via inhalation (e.g., filamentous fungi, Mycobacterium tuberculosis); or when a highly virulent organism is suspected.1
There are three classes (I, II, and III) of BSCs, and Class II is further divided into four types: A1, A2, B1, and B2. In the clinical laboratory, the most commonly used BSCs are Class II, Type A1, and Type A2. When used properly, these BSCs provide protection for personnel, the environment, and the product by directional airflow and high efficiency particulate air (HEPA) filtration of exhaust air.
There are several other laboratory engineering controls. The use of centrifuge safety equipment protects against the release of aerosols. Centrifuge safety cups, rotors with covers, removable centrifuge rotors and O-rings are also effective controls for reducing aerosols. Pipetting aids such as bulbs or autopipettes, or pipettes with cotton plugs or filters, are recommended for the safe use of pipettes. Additionally, splatter guards or shields can protect one from exposure when opening specimen containers or transferring specimens to additional containers. Enclosed electrical incinerators reduce splatters when decontaminating bacteriological loops. Hand hygiene sinks that operate hands-free and centrifuge tubes with caps also help prevent the spread of infectious material.2
Personal protective equipment
Personal protective equipment (PPE) is equipment worn to minimize exposure to hazards that cause serious workplace injuries and illnesses. These injuries and illnesses may result from contact with chemical, radiological, physical, electrical, mechanical, or other workplace hazards.3
Some elements of PPE include:
- Protective clothing
- Face and body protection
- Gloves
- Footwear
- Respiratory protection
Detailed information on PPE can be found in M29—Protection of Laboratory Workers From Occupationally Acquired Infections.4
Work practice controls
Work areas should be free from clutter and distractions. The laboratory technical areas should be clearly designated as “clean” or “contaminated.” All equipment and devices coming in direct contact with any of these materials should be considered contaminated. The designation of the technical area as either “clean” or “contaminated” determines work and housekeeping practices. If technical areas are considered “clean” areas, work practices entail efforts to prevent contamination of telephones, video display terminal keyboards, doorknobs, and other items commonly touched by ungloved hands. To protect against gross contamination, preventive practices can include plastic coverings for computer keyboards and telephones.1
Gloves should be removed before handling telephones, uncontaminated laboratory equipment, doorknobs, etc. Alternatively, specific devices, such as computer keyboards and telephones, may be specially labeled as biohazards and used only with gloved hands. Care must be taken not to use these marked devices with ungloved hands. Gloves and all other PPE should be removed before leaving the laboratory. Gloves should be disposed of properly according to institutional and governmental rules. Hands should be washed after removing gloves before leaving the laboratory.1
Personnel responsibility
Food, drink, and substances that provide potential hand-to-mouth contact are prohibited in technical work areas. Specimens containing a variety of pathogens handled daily in the technical work area and stored in laboratory refrigerators provide a potential source of contamination of food and drink. Refrigerators reserved exclusively for food storage may be located in areas in which eating and drinking are permitted. A policy should be established to ensure that food and specimens are not stored in the same refrigerator.
Application of cosmetics in the technical work area is prohibited. Hair should be secured back and off the shoulders to prevent contact with contaminated materials or work surfaces and to prevent shedding organisms into the work area. It is also important to keep hair out of moving equipment, such as centrifuges or microtomes. Men with beards should observe the same precautions provided for hair.
Personal belongings (e.g., purses, coats, prepackaged foods, medications) should not be stored in the technical work area. For security and infection prevention and control purposes, these items should be kept in staff lockers.
Personal electronics should not be used in the technical work area in the following circumstances:5
- When working with hazardous materials of any category (chemical or biological)
- When wearing gloves or other PPE, with the exception of a laboratory coat
- While performing work on laboratory specimens, data, or any process that may affect testing outcomes
- When in an area in which they might distract or interrupt others
- When in an area in which accidental release of protected health information could occur
- If they cannot be worn without hanging wires or other dangling accessories that may pose a safety hazard
- If they interfere with an employee’s ability to detect potential hazards, such as hearing an alarm or an approaching obstacle
All personal electronic devices should be protected from laboratory hazards and possible contamination.6
Transport and shipment of specimens
Any time specimens are transported, an increased risk exists for the possibility of breakage occurring and the subsequent release of hazardous materials into the environment. The use of engineering controls such as carts, leak-proof carrying containers, and absorbent materials needs to be implemented.7 Personnel transporting the specimens should use the appropriate PPE for the materials they are handling.
The transport of hazardous materials outside the facility is governed by various government and regulatory agencies’ regulations. The United Nations has developed standards for the shipment of dangerous goods.8 The International Air Transport Association (IATA) provides a manual in consultation with the International Civil Aviation Organization for the transport of dangerous goods by commercial carriers.9 The US Postal Service and the US Department of Transportation (USDOT) have synchronized their requirements with IATA in an effort to standardize the shipment of hazardous materials. Additionally, if materials are being shipped internationally, countries may have additional regulations that need to be followed.
Whether couriers are employees of the laboratory, employees of a contractor, or independent contractors, they have the potential of being exposed to highly infectious pathogens. On the job, safety is very important not only for the courier’s personal safety, but for the safe handling of the specimens and safety of the general public. The organization needs to develop a system and a plan for storing specimens safely and securely during transport. The courier organization needs to have a plan in place, the necessary equipment, and appropriate PPE in case of a spill or release into the environment.
The laboratory is responsible to the community to ensure that appropriate hazardous waste handling policies are developed and rigorously followed. The disposal of chemical, radiological, and infectious wastes and effluents is strictly regulated by federal, regional, and local authorities. Details concerning the disposal of each type of waste are covered in individual sections of GP17— Clinical Laboratory Safety.1 Users should refer to CLSI’s M29 for additional information on infectious waste disposal.4
Conclusion
A comprehensive general safety program encompasses all aspects of daily laboratory operations, including engineering controls, personal protective equipment, work practice controls, transport and shipping of specimens, and waste disposal.
Detailed information on the implementation of a safety program, including roles and responsibilities of laboratory employees, specialized safety programs, fire prevention, and emergency management can be found in CLSI’s GP17—Clinical Laboratory Safety.1
References
1. CLSI. Clinical Laboratory Safety; Approved Guideline—Third Edition. CLSI document GP17-A3. Wayne, PA: Clinical and Laboratory Standards Institute; 2012.
2. US Department of Labor, Occupational Safety and Health Administration. Engineering Controls. http://www.osha.gov/SLTC/etools/hospital/lab/lab.html#EngineeringControls. Accessed February 10, 2023.
3. US Department of Labor, Occupational Safety and Health Administration. Safety and health topics: Personal protective equipment (PPE). http://www.osha.gov/SLTC/personalprotectiveequipment/. Accessed February 10, 2023.
4. CLSI. Protection of Laboratory Workers From Occupationally Acquired Infections; Approved Guideline—Fourth Edition. CLSI document M29-A4. Wayne, PA: Clinical and Laboratory Standards Institute; 2014.
5. US Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health. Guidance on emergency responder personal protective equipment (PPE) for response to CBRN terrorism incidents. http://www.cdc.gov/niosh/docs/2008-132/. Accessed February 10, 2023.
6. OSPHL. Use of Personal Electronic Devices at the Oregon State Public Health Laboratory. ADM 136. Portland, Oregon: Oregon State Public Health Laboratory; 2009.
7. US Department of Labor, Occupational Safety and Health Administration. Bloodborne Pathogens. http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10051. Accessed February 10, 2023.
8. UN. Recommendations on the Transport of Dangerous Goods: Manual of Tests and Criteria. Amendment 1 of the 5th Revised Edition. Geneva, Switzerland: United Nations, Economic Commission for Europe; 2012.
9. IATA. Dangerous Goods Regulations. Montreal, Quebec: International Air Transport Association; 2010.
