Friday 7 March 2014

Biohazard Control

Working in biological containment facilities or with infectious agents is serious business. The research performed usually entails indigenous or exotic agents with the potential for severe or lethal disease. Two examples of infectious pathogens that have received a lot of attention recently are yellow fever and West Nile virus. Obviously, if released they have the potential to cause extensive harm or damage to people, the environment, and the community. Needless to say, we do not want these agents to get out into the community nor do we want our employees who are working with these agents to be in harm’s way. The foundation for safe operation of any biological containment facility is an effective exposure control plan. This article discusses the basic elements of a comprehensive exposure control plan, what each element should contain, and tips on successful implementation.

The exposure control plan is basically a biosafety manual written 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 andBiomedical Laboratories, which contains comprehensive information on biological risk assessment and summary statements for many common infectious agents.

An effective exposure control plan is comprehensive, clearly written in concise terms, well organized, distributed to all people who must enter or work in the containment lab, and, most important, read and understood by all. A good comprehensive exposure control plan will contain at least seven main sections. These are general laboratory function, specific facility design and operational procedures, special laboratory safety equipment and personal protective equipment (PPE), laboratory research practices and procedures, health and medical monitoring requirements, emergency procedures, and employee training. Let’s take a look at each of these chapters to see what they should include.

General laboratory function

The opening section will provide a clear organization of personnel and assign responsibilities for all who work in and support the containment laboratory. How access is controlled is of primary importance. The laboratory director has ultimate responsibility. Access should be restricted to only certified people who are absolutely necessary. Certified means they understand the potential biohazard, have demonstrated proficiency in the laboratory’s procedures, and have complied 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 as well. Finally, procedures for identifying, reporting, and correcting problems or violations of protocol are detailed.

Specific facility design and operational procedures

Specific laboratory layout and operations are described in this section. Included are security access mechanisms; self-closing, lockable doors; and other security measures. Proper signage indicating agents present, contact information for the principal investigator and other responsible people, and any special requirements are posted at all access points. The design of directional airflow from clean areas toward contaminated areas is described, and procedures for checking proper operation by laboratory staff are outlined. Measures are included for checking and ensuring that the surfaces of all walls, floors, and ceilings are smooth, impermeable, and easily cleaned and that all penetrations are sealed. Pest management is addressed here as well, with an appropriate insect and rodent control program.

Special laboratory safety equipment and PPE

This is arguably one of the most important parts of the exposure control plan. It should explain the PPE that must be worn. Describe where PPE is stored as well as when and where it is used and how it is removed and discarded. It 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 also be included.

Laboratory research practices and procedures

The heart of the exposure control plan is contained in this section. It addresses safe handling and storing of viable material, including biological safety cabinet use, handling frozen samples, and use of secondary containers. Procedures for using and disposing of sharps, found in most containment laboratories, are paramount. Addressed in this section are waste handling and disposal, decontamination, and housekeeping (e.g., cleaning up at the end of the day or after finishing a research protocol).

Health and medical monitoring requirements

The purpose of this section is to provide another level of protection against laboratory-acquired illness by documenting 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 exposure control plan should clearly define with a welldocumented rationale what is required and who is covered.

Emergency procedures

This segment describes procedures for an accident, spill, release, or exposure that contaminates or injures laboratory staff or the environment. A good reference for putting this section together would be the OSHA bloodborne pathogen standard, 29CFR1910.1030.2 Everyone working in the facility should be thoroughly versed in the emergency procedures. Spill kits should be maintained 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.

Employee training

We wrap up our exposure control plan with the chapter covering employee training. The first step is to make sure everyone who will be working in the containment facility has read and understands this exposure control plan. They should be informed about each infectious agent present, the risks associated with these, and the signs and symptoms of infection or disease. This training, along with bloodborne pathogen training, should be renewed annually and written documentation kept on record.

There you have our quick outline for putting together an effective exposure control plan. We have just touched on each topic briefly in this article. Future articles will probe deeper into select sections, providing additional details as well as tips for success and traps to avoid. Watch this column for more helpful information. As always, the Safety Guys welcome your comments and questions, so we hope to hear from you. Until then, stay safe.

Source: Laboratory Manager

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