Infection control
by Brenda E. Barry, Ph.D
Biosafety guidelines protect laboratory workers
Exposures to infectious biological agents are serious potential health hazards during many routine cell and tissue culture techniques used in biotechnology and pharmaceutical laboratories.
Development of new products from cells and tissues for therapeutic use, isolation and identification of genes and introduction of genes into microorganisms, plants, animals and human cells are all current and expanding biotechnologies. However, these procedures can present health risks for infections in laboratory workers during the handling of viruses, viral vectors, recombinant DNA (rDNA), biological organisms containing rDNA, bacteria and fungi.
 A biological safety cabinet minimizes worker exposure to aerosols or splashes of infectious biological agents. |
To address these health concerns, the Centers for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH) have developed biosafety guidelines that are summarized in their publication, Biosafety in Microbiological and Biomedical Laboratories (BMBL). In addition, the Occupational Safety and Health Administration (OSHA) Bloodborne Pathogens Standard (Title 29 Code of Federal Regulations Part 1910.1030) applies to laboratory workers who come in contact with the human blood, bodily fluids and tissues frequently used in research laboratories.
Biotechnology firms understand the importance of complying with the BMBL biosafety guidelines and the blood-borne pathogens standard. Yet, remaining in compliance can be demanding as research and development efforts continue to expand into new areas.
As a proactive approach, biotechnology companies are recognizing the value of investing in a laboratory review to ensure compliance with the existing guidelines and standards.
One method to assist in compliance with BMBL guidelines is to conduct a laboratory review. This can be done either with the help of a consultant or by devising a compliance checklist that is customized to a lab.
A fundamental element of the laboratory review process is recognition that working safely in laboratories requires integration between use of safe practices by laboratory workers and the design and operation of laboratory buildings.
This combination of approaches, termed “containment” in the BMBL, includes primary containment provided by the use of good microbiological techniques and safety equipment as well as secondary containment provided by the design and operational procedures used by the laboratory facility. The BMBL highlights importance of containment by noting that in the last 30 years there have been 24 documented cases of workers who developed infections from work with primary cell cultures, particularly rhesus monkey kidney cells.
The biosafety guidelines summarized in the BMBL can be simply defined as a group of practices and procedures designed to provide safe environments for individuals who work in laboratories with potentially hazardous biological agents.
Work with biological agents is classified into four distinct biosafety levels, BSL-1 to BSL-4, based on the potential health risks for both individuals who work in laboratory environments and for members of the surrounding community. Each of these biosafety levels is matched with increasingly restrictive practices and facilities that are designed to reduce risks for exposures to potentially hazardous biological agents.
Biosafety level 1 (BSL-1) and biosafety level 2 (BSL-2) practices and containment are applicable for the majority of work conducted in today's biotechnology and pharmaceutical laboratories. BSL-1 is suitable for work with well-characterized biological agents that are not known to consistently cause disease in healthy adult humans; they pose minimal potential health hazards for laboratory personnel and the environment.
BSL-2 is applicable for work with biological agents that present moderate potential health hazards to laboratory personnel and the environment. Level BSL-2 indicates that individuals working directly with the biological materials are at moderate risk for infection through skin and eye exposure, skin puncture and ingestion. To minimize potential exposures to aerosols or splashes of infectious biological agents, designated procedures are conducted in biological safety cabinets (BSCs) or other physical containment equipment.
Filtration mechanisms are an essential laboratory design feature for reducing levels of infectious agents in the air entering a laboratory and for removal of these agents from air exiting the laboratory. For example, such filtration is critical for biotechnology and pharmaceutical companies to ensure product sterility.
High efficiency particulate air (HEPA) filters are also integral components for optimal operation of BSCs. These units provide the primary means of containment for working safely with potentially hazardous biological materials and, when combined with good microbiological practices, can protect both laboratory personnel and the environment. BSCs are designated as Class I, II or III based on specific airflow patterns within the BSC and on the locations of the HEPA filters within the unit. To ensure optimal operation, it is very important that BSCs are tested and certified annually, preferably by someone accredited by the National Sanitary Foundation (NSF). BSCs should always be certified when they are first installed and whenever they are moved, even to a nearby laboratory.
Although no specific federal regulations apply to the majority of cell and tissue culture activities in laboratories, the Blood-borne Pathogens Standard does apply to laboratory workers who come in contact with human blood, bodily fluids or tissues. This standard was issued in 1991 based on health concerns related to increased risks for exposures to certain blood-borne pathogens (BBP), such as human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV) and other infectious agents that may be present in human materials. In addition to HIV and the hepatitis viruses, the standard covers a wide variety of blood-borne diseases.
Sources of potential exposures to BBP include a variety of potentially infectious materials (PIMs), including all human blood, blood products, certain body fluids, any body fluids in which visible blood is present, and any unfixed tissue or organ from a human (living or dead). BSL-2 is the level applicable for activities involving BBP.
The Blood-borne Pathogens Standard requires that an Exposure Control Plan be written and implemented. The Exposure Control Plan includes several required elements and policies and procedures to eliminate or minimize BBP exposures. These elements include identifying all individuals in a laboratory group who may be at risk for BBP exposures, annual training and providing appropriate personal protective equipment. Unlike the biosafety guidelines, the OSHA BBP standard has the force of law, and non-compliance can result in serious financial penalties.
In summary, compliance with the biosafety guidelines recommended by the CDC and NIH and with the BBP standard requirements mandated by OSHA provides clear advantages for biotechnology and pharmaceutical companies. The laboratory review process can insure compliance and address a company's ethical responsibilities to its employees as well as reducing potential liability concerns related to exposures to infectious agents. This approach can support companies in meeting the CDC-NIH goal of providing safe environments for both laboratory personnel and the surrounding community.
Brenda E. Barry received her Ph.D. in pathology from Duke University. She is a Senior Associate and toxicologist at Environmental Health & Engineering, Inc. in Newton, Massachusetts. Phone 617-964-8550, email [email protected].
How to maximize a lab review
Biotechnology and pharmaceutical companies often want to know how they can maximize the benefits provided by a laboratory review. Answering a series of questions prior to the review can be very helpful for understanding the focus of the review, the elements that will be addressed, and improving the value the of the review process for the company.
- Do you have a biosafety manual and when was it last updated?
- How do you manage and maintain training records for your employees?
- Who conducts the training for new and current employees?
- Who oversees proper use of personal protective equipment?
- Do you have biosafety cabinets and who oversees annual testing of these units?
- Who oversees signage and labeling issues?
- How are biohazardous waste and sharps disposal managed?
- If any employees handle bloodborne pathogens, who oversees compliance with the OSHA Bloodborne Pathogens Standard requirements?
- Are there special use areas or restricted use areas in your facility?