ABSA Comments Regarding National Committee of Clinical Laboratory Standard, NM29-3A, Protection of Laboratory Workers from Occupationally-Acquired Infections

a letter written by Stefan Wagener, Ph.D., RBP, CBSP
President, ABSA
5 April 2004

Patrice Polgar, M.T. (ASCP), M.S.H.A
National Committee of Clinical Laboratory Standards
940 West Valley Road, Ste. 1400
Wayne, PA 19087-1898


April 5, 2004

Dear Ms. Polgar,

The American Biological Safety Association (ABSA) is an organization of biological safety practitioners who work in a variety of academic, governmental, healthcare and private work environments. ABSA has many members in the United States, Canada, and in other countries. We are recognized as a leading authority in the field of biological safety. We appreciate the opportunity to participate as an advisor in the review and update of your most recent draft revision of guideline M29-3A, Protection of Laboratory Workers from Occupationally-Acquired Infections.

After reviewing the document, we suggest including a short statement regarding the Centers for Disease Control and Prevention (CDC) Select Agent program (42 CFR 73), along with a listing of the regulated organisms and toxins. The revised select agent possession requirements have eliminated many of the exemptions from this regulation that clinical laboratories were eligible to claim in the past. Clinical laboratories comprise the largest group of new registrants in the CDC Select Agent program, according to materials presented by the CDC at the January 2004 CDC/ABSA Biosecurity Symposium. A clinical laboratory that does not need to possess select agents would still need to prepare and forward a CD-1318 Form in the event that they confirmed that they had isolated such an agent from a clinical specimen. For these reasons, it would be prudent to make such a reference in your guide so that the list can be consulted by the readers and applicability of the CDC Select Agent program determined.

Few clinical laboratories should be maintaining any wild poliovirus at this time. However, should they retain specimens that contain this pathogen, they should be aware that the biosafety level 2 (BSL-2) work practices and containment typically utilized in a clinical laboratory would not be appropriate in the future as the World Health Organization's (WHO) global polio eradication effort progresses. Currently BSL-2-Polio is in effect and differs from the regular BSL-2 of clinical laboratory use. A stage will be reached as part of that effort where the recognized standard of care for the handling of such materials will be BSL-3 work practices and containment. Clinical laboratories that may have wild poliovirus on hand should be aware of this future consideration. It is suggested that a reference be made to the World Health Organization (WHO) Global Action Plan for Laboratory Containment of Wild Poliovirus", 2nd edition, Draft, July 25, 2002.

We commend your elimination of many of the entries of agent summaries that had been Appendix A of your document. Adding the reference to the current edition of "Biosafety in Microbiological and Biomedical Laboratories" (BMBL) will help a reader access the most current guidance for a specific agent. As mentioned previously, most clinical laboratories do their work with BSL-2 work practices and containment, and you are providing that criteria in the text of your document where it can be readily accessed. Please note with regard to the BMBL, this publication is being revised and the next edition is scheduled to be released shortly after your document is scheduled to be released. You may want to consider delaying the revision of your document until after the next edition of the BMBL is released. This would allow for references in your document to an updated edition of the BMBL.

Our specific comments follow the sections of your guideline, and they are as follows:

3 Definitions

Please consider the following italicized edits regarding definitions:

Aerosol - Microbial aerosols are suspensions of particles in air consisting partially or wholly of microorganisms. They may remain suspended in air for long periods of time, some retaining and others losing infectivity or virulence. Particles in the 1 to 5 um range are easily drawn into the alveoli of the lungs and may be retained there. (Note that this definition is consistent with the definition provided by the American Public Health Association (APHA) in their "Manual for Communicable Diseases of Man".)

Blood-borne pathogens - Pathogenic microorganisms that are present in human blood, blood products or other potentially infectious materials and can cause disease in humans.

Droplet Nuclei - Usually the small residues that result from evaporation of fluid from droplets emitted by an infectious host, or created by an atomizing device or accidentally in microbiology laboratories, autopsy rooms, etc. They usually remain suspended in air for prolonged periods of time. (Note that this definition is consistent with the definition provided by the American Public Health Association (APHA) in their "Manual for Communicable Diseases of Man".)

Engineering controls - Controls (e.g., Biological Safety Cabinets, centrifuge safety cups, sharps disposal containers, self-sheathing needles, safer medical devices such as sharps with engineered sharps injury protections and needleless systems) that isolate or remove the hazard from exposure in the workplace. (Note that the reference to bloodborne pathogens has been removed, as engineering controls are not exclusive to bloodborne pathogen hazards.)

Medical Waste - Regulated materials generated as a result of diagnosis and treatment of patients. (Note that the definition of medical waste will vary by state and may include additional wastes such as those from the treatment of animals.)

Microbicide - A substance that kills all living microorganisms including spores, both pathogenic and nonpathogenic.

4 Acronyms/Abbreviations

Given the emergence of sudden acute respiratory syndrome (SARS) since 2003, we suggest including the term, "SARS" in this section.

Please consider the following italicized edit regarding the acronym HEPA:

HEPA Filtration - high-efficiency particulate air filtration.

5.1 Epidemiology

The reference to the CDC website in Table 2 should be corrected to read "gov" instead of "goc". Percutaneous

The fourth sentence is confusing and requires clarification. It reads "Twenty-six five of them have...".

5.3.1 Airborne Transmission

There is a statement in the paragraph under Bacillus anthracis indicating, " Any work with B. anthracis requires special security considerations due to its potential use for purposes of biological terrorism." We would suggest that you include a statement, "See 42 CFR 73 for full details regarding the Select Agent and Toxin programs requirements." Similar consideration should be made to include such a statement under the agent statements for Brucella (the specific species regulated under the Select Agent program are Brucella abortus, Brucella melitensis and Brucella suis), Francisella tularensis, Burkholderia pseudomallei, and Yersinia pestis.

In the "Editor's Note" section under Bacillus anthracis, the sentence beginning "These materials...." should be edited to read, "These materials should be transported...".

In the Mycobacterium tuberculosis section, one statement should be edited to note that, "Procedures are conducted using annually certified Class II biological safety cabinets and in accordance with the latest recommendations on working safely...." In the following paragraph where criteria for respirators are given, one of the statements should be modified to indicate, " the ability to fit the different facial sizes and characteristics of healthcare workers that can usually be met by making respirators available in at least three sizes from two different respirator manufacturers". Differences in facial types may not always be able to be addressed by differences in sizes of respirators available from the same manufacturer. Having multiple sizes available from two different manufacturers better enables such accommodations to be made.

In the "NOTE" following "Viral Agents of Bioterrorism", there are two references to "biological safety cabinet". To be consistent with the previous reference of "BSC" in an earlier section of the publication, these should be changed to "BSC". Also in this section, there is a reference to the American Society for Microbiology (ASM) "Sentinel Laboratory Guidelines for Suspected Agents of Bioterrorism, 2003". This section should be expanded to include additional information on the role of the sentinel laboratories.

5.3.3 Transmission by Contact

After the words, "vancomycin intermediate Staphylococcus aureus" you should include, "VISA" and after the words, "vancomycin resistant Staphylococcus aureus" include the words, "VRSA". Also, the genus and species should be italicized as Staphylococcus aureus. The sentence that begins, "With the latest laboratory testing..." is not a complete sentence. Also, the sentence that begins "...in a Class II (or highter) biological safety cabinet with disposal surgical/examination of gloves," should be changed to "...in a Class II (or higher) biological safety cabinet with disposable surgical/examination gloves." Latex Hypersensitivity

The American Society of Testing and Materials (ASTM) in ASTM D 3578-00a recommends that latex gloves should contain no more than 200 micrograms/decimeter squared of water extractable protein in order to be considered low protein. This limit or ASTM standard should be noted in the recommendation for the selection of low protein gloves.

6.3 Biological Safety Cabinet

Please refer to our comment that follows regarding Appendix B regarding terminology used to describe types of biological safety cabinets. Those comments will affect the references made to Class IIA and Class IIB biological safety cabinets being made in this section. Disinfectants and Sterilants

It is suggested that the paragraph "The government agencies..." be rewritten for better clarity as follows. "The FDA and EPA share responsibility for the regulation of disinfectants and sterilants. The FDA regulates chemical germicides formulated as antiseptics, preservatives, drugs that are used on or in the human body, and sterilants and high-level disinfectants for processing reusable medical and dental devices. The EPA regulates the other disinfectants used for laboratory disinfection and housekeeping purposes. A complete discussion of this topic and a list of helpful websites are found in Appendix C."

The Internet link to http://ace.orst.edu/info/nain/list/htm is no longer active. A message at that link indicates the Oregon State Program that had been supported by Environmental Protection Agency (EPA) funding was not renewed by the EPA and the program had closed on March 31, 2002. There is a link that transfers you to http://www.epa.gov/oppad001/ the antimicrobials division of the EPA.

The Internet link to http://www.fda.gov/cdrh/index/html produces a message on the Food and Drug Administration (FDA) web site indicating, "Page Not Found".

These web sites are also subsequently referenced in Appendix C, "Regulation of Antimicrobial Chemicals". Sodium Hypochlorite

The "NOTE" in this section states that dilutions should be made weekly with tap water to prevent the loss of germicidal action during storage. It is recommended that the frequency be changed from "weekly" to "daily". This is suggested as variations in tap water may result in a significant reduction in available chlorine. Lack of available chlorine will decrease the efficacy of the solution.

In the paragraph located under Table 6, there is a reference to scraping off dried blood. Given the need to use a potentially sharp object to perform the scraping, a better approach would be to utilize the following procedure and reword the paragraph to state, "If a surface or medical device is contaminated with dried blood or body fluid, remove all visible traces of it before decontamination. The dried blood should be wetted and softened with diluted bleach or detergent disinfectant. If the material cannot be removed by wiping, repeat the application and allow to stand for a longer period of time until the material can be wiped off. After removal of the dried blood, decontaminate or sterilize the surface depending on the intended use of the device."

6.4.2 Procedures and Products

It is suggested that this section be rewritten for improved clarity. The following wording is suggested. "Sterilization and disinfection procedures generally used in healthcare facilities are able to sterilize or disinfect medical devices, and decontaminate and sanitize surfaces. Germicidal activity of disinfectants is classified as high-level, intermediate-level, or low-level. Critical medical devices that penetrate tissues, thereby making contact with normally sterile areas of the body, or through which blood flows should be sterilized before use (e.g., bone-marrow needles). Semi-critical medical devices that come into contact with mucous membranes should be sterilized or receive high-level disinfection before use. Bloodborne pathogens such as HBV, HCV, and HIV, are usually inactivated by all levels of disinfectants. However, OSHA requires the use of EPA registered disinfectants that are tuberculocidal or effective against HIV-1 and HBV. Several commercial, quaternary ammonium-based housekeeping products have recently been approved by EPA to make claims of activity against HIV and HBV. However, if you are processing samples other than blood or serum, it is recommended to use a tuberculocidal disinfectant to handle other types of organisms, such as enteroviruses. Refer to the manufacturer's instructions for appropriate usage instructions."

7.5 Transport

Regulated Medical waste is a hazardous material regulated by the U.S Department of Transportation (USDOT). Containers used to ship medical waste to off-site treatment facilities need to meet the (USDOT) requirements, but they may also need to address some specific state regulations. State environmental management agencies should be able to provide appropriate guidance.

9.7 Shipping Specimens

Please review and consider the following highlighted edits to portions of your guidance on the shipment of specimens:

The fifth paragraph that begins with "Within the international..." could be rewritten for clarity as "Hazardous materials are divided into nine classes. Infectious materials and diagnostic specimens are placed in Class 6, Division 6.2. Dry ice is placed in Class 9 and liquid nitrogen in Class and Division 2.2."

Compliance with transport regulations for infectious agents requires ensuring that specimens and samples are classified and packaged correctly. Requirements for packaging are generally based on a three-container system, with the primary and secondary packages required to be watertight. Absorbent is required between the primary and secondary packages in case of accidental breakage and spill. If transporting liquids by air transport, either the primary or the secondary container must be capable of withstanding a pressure differential. Once the package "combination" is determined, this package system must meet the UN performance tests detailed by each regulatory authority mentioned above. For diagnostic samples, the packaging requirements are similar, but the performance test requirements are less stringent.

In essence, any package offered for transport must be capable of meeting all conditions normal to transport, including pressure, vibration, shock, etc.

Packages require other specific external markings to designate the contents and the inherent risk. This includes the designation of a UN number (UN 2814 "infectious substance affecting humans," UN 2900 "infectious substance affecting animals, UN3373 "diagnostic specimen with no known serious human or animal disease), and in some instances appropriate safety labels that include the international symbol for infectious substances (see figure). Packages may also require the creation of a waybill for tracking purposes.

It is mandatory that all laboratory personnel who ship infectious substances be certified as knowledgeable about packaging requirements, and that the certification is based upon a training program (see 49 CFR, 172.700). It is the responsibility of the employer, and not the trainer, to certify that the person is knowledgeable. Under IATA regulations, recertification is required every second year. In the United States, the Department of Transport only requires recertification every 3 years. If "diagnostic specimens" are the only material transported, lesser training requirements are specified (49 CFR 173.199).

The shipment of specimens can be a complex task. The intent of these edits is to identify some of the fundamental considerations for this activity.

10 Mycobacterium tuberculosis in the Healthcare setting

The tasks that need to be performed at Biosafety Level Three (BSL-3) should be identified. The tasks that are to be performed at BSL-2 need to be identified as well. If these tasks are not detailed here, then readers should be referred to the most current version of "Biosafety in Microbiological and Biomedical Laboratories" (BMBL) or the CDC "Guidelines for working with TB in Laboratories" for guidance.

10.4 Respiratory Protection

The scope of the document includes workers who procure specimens and wear respirators as required for the collection of specimens from TB patients in respiratory isolation. Respirators are also needed for TB spill responders, and laboratory workers in TB labs at the BSL-3 level. Also note that a Respiratory Protection Program is required per the OSHA Respiratory Protection Standard, and workers must be medically cleared and fit-tested to wear the N95 respirators.

12.3.1 Centrifugation

It is suggested that this section be rewritten for improved clarity. The following wording is suggested. "All centrifuges should have lockable lids that should be secured while the rotor is moving. Tubes should be properly capped and sealed before insertion into the centrifuge. Care must be taken when opening the tubes. To reduce the risks associated with aerosols, all centrifuges should be equipped with sealed rotors or safety cups. Sealed rotors or safety cups, should be used for processing highly concentrated or large volumes of infectious agents and specimens that may contain agents that are spread by airborne transmission, e.g., M. tuberculosis. Sealed rotors or safety cups should be opened inside a biosafety cabinet after centrifugation is complete. Where safety cups and/or sealed rotors cannot be used, the centrifuge should be placed in a containment device or biological safety cabinet designed for this purpose, since the motor may produce strong air currents and turbulence that may disrupt the laminar airflow. (See Appendix B for exceptions.)."

12.3.2 Sedimentation and Filtration Equipment

It is suggested that the first sentence be rewritten to say, "Sedimentation and filtration equipment should be set up so that it is stable and not prone to tip over."

12.3.3 Vacuum Pumps

It is suggested that the sentence be rewritten to say "If a mechanical vacuum apparatus is used, it should be connected to a liquid disinfectant trap with a hydrophobic filter to collect any contaminated aerosols."

Appendix B: Biological Safety Cabinets (BSC's)

National Sanitation Standard (NSF) Number 49, "Class II (laminar flow) Biosafety Cabinetry" was revised in 2002. The current version of this document is now NSF/ANSI -2002e. This revised standard changes definitions and terminology used to describe biological safety cabinets. Class II, Type A cabinets are now defined in that standard to be "Class II Type A1 cabinets". Class II, Type B3 cabinets are now defined in that standard to be "Class II Type A2 cabinets".

Your references to Class II, Type A, and Class II, Type B3, should be edited as indicated above. Additionally, it is indicated that Type B3 cabinets (now Class II, Type A2 cabinets) are to be hard ducted to the building exhaust system and have negative pressure plena. It should be indicated that exhaust canopy connection should be used to direct exhaust from the cabinet in accordance with guidance contained in the revised NSF standard.

Appendix E: Occupational Safety and Health Administration (OSHA) Instruction

The fax number in your document for the OSHA Region 6 office is (214) 767-4137. The fax number posted on the OSHA web site for the OSHA Region 6 office is (214) 767-4693.

Thank you for providing ABSA with the opportunity to participate as an advisor. If additional time is allocated by NCCLS for the review and update of this document, ABSA members are prepared to be of further assistance in developing a more useful and current document. We look forward to future opportunities.


Stefan Wagener, Ph.D., RBP, CBSP (ABSA)
American Biological Safety Association (ABSA)

Stefan Wagener, PhD, RBP, CBSP, President, ABSA - Comments Regarding National Committee of Clinical Laboratory Standard, NM29-3A, Protection of Laboratory Workers from Occupationally-Acquired Infections, American Biological Safety Association (5 April, 2004),


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