Working with Biohazards
Fundamentals of a comprehensive exposure control plan
Working with human pathogens or biohazards poses serious risks, not only for employees, but for the public and communities as well. Infectious agents such as microorganisms, viruses, recombinant or synthetic nucleic acid molecules, and biological toxins present a potential for severe or lethal disease, adverse health effects, or contamination. Any unplanned exposure or release has the potential to cause extensive harm or damage to people, the environment, and society.
The foundation for safe handling and research with infectious/biohazardous agents is an effective exposure control plan (ECP). This article discusses the basic elements of a comprehensive exposure control plan, what each element should address, and advice for successful implementation.
The ECP is essentially a biohazard safety manual developed to address the unique conditions of the current research, facility design, and personnel operations necessary to carry out the laboratory’s mission. One excellent free reference is the CDC’s Biosafety in Microbiological and Biomedical Laboratories1 (BMBL), which contains comprehensive information on biological risk assessment and summary statements on many common infectious agents.
An excellent ECP is comprehensive, clearly written, and well organized. A good companion to the BMBL is OSHA’s model ECP contained in Appendix D of 29CFR1910.1030.2 However, effectiveness is ensured only when all persons who must enter or work in the containment areas are trained on and understand the key elements.
ECP critical elements
Your exposure control plan should contain main sections that address ECP administration, employee exposure determination, implementation and control methods, and health and medical monitoring requirements, including appropriate pre-exposure prophylaxis, emergency procedures, and postexposure evaluation, employee training, and record keeping. Below we describe what each of these sections should address.
ECP administration
The opening section should provide a clear organization of personnel and assign responsibilities for implementation and support for the facility. The responsibilities of positions and/or departments are outlined for maintaining, reviewing, and updating the ECP. In addition, responsibilities for maintaining and providing necessary personal protective equipment (PPE), engineering controls, and other infrastructure and equipment are contained here. Finally, responsibilities for medical actions, employee training, incident follow-up, and record keeping should also be listed.
Employee exposure determination
All employees who are determined to have potential occupational exposure, and thus need to comply with the ECP, are defined in this section. Provide a list of all job classifications at the facility that have potential for exposures. Conduct job hazard analyses and exposure assessments where needed and as necessary.
Implementation and control methods
This section contains all the specific procedures for working safely. Everything from universal precautions to engineering controls to PPE is detailed and described. Specific laboratory layout and operations are also explained in this section. Controlling access is extremely important, and access should be restricted to only certified persons who are absolutely necessary. Certified means they understand the potential biohazard, have demonstrated proficiency in the laboratory’s procedures, and comply with the health and medical entry requirements.
Proper entry and exiting procedures for staff, visitors, and maintenance/custodial workers are clearly established in this section. Included are security access mechanisms, such as self-closing, lockable doors, and other security measures.
Proper signage indicating agents present, contact information for the principal investigator and other responsible persons, and any special requirements are posted at all access points.
Engineering controls, such as interlocks and positive pressure airflow, and the means for checking they are properly functioning are spelled out in detail. The handling and disposal of sharps and other biohazardous waste are addressed. Ensure proper labeling is clearly described, including use of warning labels and red bags.
PPE is one of the most important parts of the exposure control plan and discussed thoroughly in this section. The personal protective equipment that must be worn is listed for each position. Describe where PPE is stored as well as when and where it is used and how it is removed and discarded. This section should cover the proper types of gloves, eyewear, and gowns or lab coats to be used.
This section also addresses proper use and maintenance of the lab’s safety equipment, such as autoclaves, biosafety cabinets, eyewash stations, safety showers, ventilation alarms, and other specially designed containment equipment. Procedures for decontaminating equipment prior to maintenance work should be included.
The implementation and control section should address safe handling and storing of viable material, including biological safety cabinet use, handling frozen samples, and use of secondary containers. Procedures for housekeeping (e.g., cleaning up at the end of the day or after finishing a research protocol) are discussed, along with special instructions for laundry.
Health and medical monitoring
The purpose of this section is to provide another level of protection against laboratory-acquired illness, and it documents necessary immunizations. Immune-suppressed individuals or persons at increased risk should be strongly discouraged from entering the facility. Depending on the agents present, vaccinations (hepatitis B), antibody testing (TB skin test), or serum storage may be required. The ECP should clearly define what is required and who is covered, with well-documented rationale.
Emergency procedures
This section describes procedures for an accident, exposure incident, or spill or release that injures laboratory staff or contaminates the environment. A good reference for putting this section together is OSHA’s bloodborne pathogens standard, 29CFR1910.1030.3 Follow initial first aid procedures and document the routes of exposure and how it occurred. Ensure spill kits are available and biohazard spills decontaminated and cleaned up as soon as possible by properly trained and equipped staff. Any incident should be completely documented with a written report, and a postexposure evaluation and follow-up should be performed.
Employee training and incident reporting
The final section of a comprehensive exposure control plan covers employee training and record keeping. First, ensure everyone who will be working in the containment facility has been trained on and understands the ECP. Inform employees about each infectious agent present, the risks associated with these agents, and the signs and symptoms of infection or disease. Make sure procedures for identifying, reporting, and correcting exposures, incidents, near misses, or violations of protocol are covered in detail. Finally, the training should be renewed annually, and written documentation should be kept on file.
References:
1) Biosafety in Microbiological and Biomedical Laboratories 5th Edition, Centers for Disease Control and Prevention and National Institutes of Health, December 2009. https://www.cdc.gov/biosafety/publications/bmbl5/
2) Model Exposure Control Plan, OSHA bloodborne pathogens standard, 29CFR1910.1030, Appendix D. Occupational Safety and Health Administration. Washington, D.C., April 2012.
3) https://www.osha.gov/OshDoc/Directive_pdf/CPL_2-2_69_APPD.pdf
4) Bloodborne Pathogens, 29CFR1910.1030, Appendix D. Occupational Safety and Health Administration. Washington, D.C., April 2012.
5) http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10051