September 1, 1998 - OSHA Post-hearing Comments

The American Society for Microbiology (ASM) would like to thank you for the opportunity to present oral testimony before the Administrative Law Judge and officials from the Occupational Health and Safety Administration (OSHA) on the proposed standard on Occupational Exposure to Tuberculosis published in the Federal Register on October 17, 1997. The ASM would like to submit the following post-hearing comments for the record.

ASM has offered and will continue to offer audio-conferences, workshops and scientific sessions and roundtables on mycobacterium tuberculosis, including coverage of appropriate laboratory safety procedures necessary when working with this infectious microorganism. The ASM also offers and encourages certification in Microbiology by the National Registry of Microbiologists (NRM). NRM certification minimizes risk to the public by identifying qualified microbiologists and encourages mastery of microbiological knowledge and skills. A major component of the certification process includes testing the knowledge of the use of appropriate safety equipment, devices, procedures and work practices to reduce the risk of acquiring laboratory infections, including tuberculosis.

The draft document contains some language of concern to the ASM because as currently written, it may be misleading to laboratorians and thus create greater hazards than currently exist. Language borrowed from other documents, when applied in this context, may contribute to the confusion. The language about disposable items not being a hazard is an example. This language may have been borrowed from a document that implied that one could safely discard disposable items such as soiled tissues in the patient care setting. That assertion is true because the coughed respiratory fluids stick to the tissue and are not efficiently re-released as aerosols. However, when applied to the laboratory setting, there are many "disposable" items that would contain aerosols at extremely high levels and represent considerable danger. Many of these disposable items would appear to be empty. For example, a plastic tube or pipette in which fluids had been agitated would still contain aerosols from the fluid even though the fluid was no longer present. A thin bored device such as a pipette or a partially closed lid on a test tube would not efficiently release that aerosol during a short interval in a biosafety cabinet. During a longer interval in a plastic bag waiting to be autoclaved or transported to a device for incineration, these aerosols would diffuse out of their temporary containers and create hazards. Thus, we drafted the response provided in the following paragraph in our comments to OSHA previously. If we can provide further clarification please let us know.

The specifications for waste disposal from the laboratory setting are inadequate and could represent a hazard to the laboratorian or to subsequent health care or contract workers who manage the waste. The wording "durable leak proof container, closed to prevent leakage, for transport from the laboratory" suggests that fluid material is the greatest hazard when in fact it is the "empty" test tubes, pipettes, etc, that contain aerosols that will diffuse out of a container that is not sealed that are most hazardous. Simple closure is insufficient to contain the truly hazardous "leakage" where aerosols are concerned. The emphasis on color coding is also hazardous because it implies that a color coded plastic bag might be used but in fact would readily release aerosols if the bag were compressed even though it might be "closed."

ASM believes that the best assurance of worker safety includes training people to understand the distinction between various types of potential hazards and the types of precautions to take based on the hazard. Contact with fluids (blood borne pathogens), contact with droplets, limited to exposures within a few feet of an ill person, and the hazards of aerosols, limited to a few microorganisms that can survive the conversion from a droplet to a droplet nucleus are all potential hazards for laboratory personnel and must be handled accordingly.

Appropriate training programs need to be conducted for laboratory personnel that include visual aids to clearly distinguish among hazards due to contact, droplet or aerosol. These could be provided by the Centers for Disease Control and Prevention through the National Laboratory Training Network (NLTN). If available, these training programs (including video programs which can be viewed without incurring travel costs) should be mandatory for directors and supervisors of laboratories who perform tuberculosis testing. Other laboratory workers should also be trained and that some effort to document that training should be required. The doctoral level clinical microbiologist who directs a mycobacteriolgy laboratory is ultimately responsible for the safety of the workers, including that of him/herself. Many of these individuals have reported to the ASM that they have safely operated a tuberculosis laboratory for years. In the aggregate, these individuals have reported hundreds of thousands of samples processed without a skin test conversion.

However, the ASM is concerned that changes in health care hiring practices over the last few years have led to a tendency to hire less trained individuals to direct and work in clinical laboratories and that this may create problems of worker safety in the future. In addition, because of health system change many clinical laboratories have begun "cross-training" their employees to do tests not previously performed. Thus, the ASM recommends that safety training in tuberculosis testing should be applied to all laboratorians working in a highly complex laboratory as defined by the Clinical Laboratory Improvement Amendments (CLIA) regulations and not just those currently in the TB laboratory. The ASM would be happy to assist OSHA in defining the specific requirements for safety training, based on the successes of many of our members who have experienced safe working environments.