OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

June 28, 1996

Mr. Daniel L. Prince
Microgen, Inc.
Post Office Box 1281
West Caldwell, New Jersey 07006

Dear Mr. Prince:

Thank you for your letter of February 5, concerning Microgen Inc. disinfectant products "D-125" and "Public Places." Please excuse our delay in responding, however, we wanted to give you a comprehensive response.

The Occupational Safety and Health Administration (OSHA) has reviewed the information provided by the Environmental Protection Agency (EPA) concerning Microgen's products, "D-125" and "Public Places." We concur with the EPA that use of the products designated above is appropriate as a disinfectant for HBV and HIV provided two conditions are satisfied. First, HBV and HIV are the only bloodborne pathogens of concern (for example, as in a research setting), and second, the products are used in the concentrations approved by EPA. When both conditions are met, we agree that Microgen's disinfectants "D-125" and "Public Places" are appropriate for use on solid, nonporous, precleaned enviromental surfaces, and the precleaning of such surfaces.

However, please note that when other bloodborne pathogens are of concern neither product is approved as a disinfectant for solid, nonporous, precleaned environmental surfaces nor for precleaning such surfaces. To date, the EPA has not approved any Microgen product to be efficacious for bloodborne pathogens other than HBV or HIV. Therefore, when bloodborne pathogens other that HBV or HIV are of concern OSHA continues to require the use of EPA-registered tuberculocidal disinfectants.

We appreciate Microgen's support of safety and health in the workplace. If you have further questions pertaining to this matter, please contact this office for further information (202) 219-8036.


Ruth McCully, Director
Office of Health Compliance Assistance

February 5, 1996

Mr. John B. Miles
Director of Compliance Programs
Occupational Safety and
Health Administration
US Department of Labor
200 Constitution Avenue, NW
Washington, DC 20212
Phone: (202)219-9308
Fax: (202)219-9787

Re: Discussion of EPA approved disinfectants to inactivate HBV and HIV in blood

Dear Mr. Miles:

As a follow-up to our earlier memorandum of 2-1-96, enclosed you will find additional information regarding the issue of decontamination of HBV and HIV. Microgen, Inc. has recently received approval from the United States Environmental Protection Agency (EPA) to market two disinfectant products (D-125 and Public Places) which inactivate Hepatitis B Virus (HBV) on hard environmental surfaces, including hard surfaces associated with blood collection. Furthermore, MICROGEN has received written clarification from the Centers for Disease Control (CDC) that hospital level disinfectants, such as our quaternary ammonium disinfectants D-125 and Public Places, can be used as part of various decontamination programs established for worker safety. D-125 and Public Places are the first and only products which conform with the requirements of the EPA,(1) CDC(2) and Occupational Safety and Health Administration (OSHA).(3) The OSHA Final Rule entitled "Occupational Exposure to Bloodborne Pathogens" (29 CFR Part 1910.1030) requires that the use of products registered with the EPA to control HBV and HIV.

FOOTNOTE(1)  Microgen EPA Approved labels (enclosed herein) contain
instructions for disinfection of HBV and HIV in blood collection centers.

FOOTNOTE(2)  See enclosed letter from Dr. Martin J. Favero of the CDC.  Dr.
Favero can be contacted for conformation at:  404-639-6401.

FOOTNOTE(3)  The Bloodborne pathogen rule concerns itself with worker
safety.  It specifically and repeatedly stipulates that HBV and HIV must be
decontaminated.  Note:  Control of Tuberculosis does not appear anywhere in
the rule.  The rule was first published in the Federal Register on Friday,
December 6, 1991 (Volume 36, Number 235)

It is our understanding that primary intent of the rule is to provide workers with direct protection against bloodborne pathogens such as HBV and HIV. When the rule was put into effect there were no EPA approved disinfectants against both HBV and HIV. Little was known about the susceptibility of HBV and HIV to liquid chemical germicides. Now, however, a great deal has been learned.(4) Namely, quaternary ammonium disinfectants quickly inactivate HBV and HIV even in the presence of five (5%) percent blood serum and in hard water. We no longer need to exclusively depend upon agents comprised of phenol, alcohol, glutaraldehyde, or peracetic acid simply because they inactivate a surrogate organism such as TB. It is a matter of record that disinfectants formulated with these active ingredients (phenolics, etc.) suffer from many disadvantages such as human toxicity, flammability, corrosivity, staining, odor and are very expensive. Given that these agents (phenolics, etc) are not registered with the EPA to inactivate HBV and have multiple disadvantages, and given that quaternary ammonium products are registered with EPA to inactivate HBV and HIV, are less expensive, more compatible with materials and safer to end-users than the aforementioned chemical agents (phenols, etc.) and because TB is not a clinically relevant organism,(5) it seems appropriate for OSHA to immediately update its policies such that the use of disinfectants registered with EPA to inactivate HBV and HIV be required.

FOOTNOTE(4)  Enclosed find the publication "Methodological Approaches to
Disinfection of Human Hepatitis B Virus", Journal of Clinical Microbiology,
December 1993.

FOOTNOTE(5)  Tuberculosis is not spread through blood; it is spread through

A summation of the fundamental reasons why the OSHA should change its recommendations so that the use of quaternary ammonium compounds with anti-HBV activity becomes the new standard in infection control are presented below:

1. It fulfills the requirement and intent of the rule promulgated by the Occupational Safety and Health Administration as published in the Federal Register (29 CFR Part 1910.1030, December 6, 1991, pages 64175 to 64182).

2. HBV and HIV are clinically relevant organisms in the practice of blood banking, TB is not.

We respectfully ask that the OSHA revise its policy such that the inactivation of HBV and HIV by EPA-registered quaternary ammonium disinfectants will now be emphasized. This will help assure that the OSHA stays in conformance with the Federal law as well as remaining consistent with current scientific, regulatory and epidemiological facts.

We would be pleased to answer any questions you may have in this regard. I will call you to discuss this letter on 2/9/96.


Daniel L. Prince, Ph.D