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.

September 17, 1993




SUBJECT:            Acceptability of Microwave Systems to Convert Regulated
                   Waste to Regular Waste

In a recent telephone conversation with a member of your staff, and in subsequent correspondence, you asked us to determine the acceptability of microwave systems to convert regulated waste into waste free of biohazardous material. While researching this matter, we contacted the Environmental Protection Agency (EPA) to determine its jurisdiction on this matter.

EPA has been studying the use of microwave systems to disinfect regulated waste since 1991. This study was finished only recently and is now under review. The results from this study, upon which EPA will base any determination, will be available in early 1994.

In the interim, EPA has indicated that if a microwave system is currently acceptable to the state and local authorities to convert regulated waste to regular waste, then EPA will defer to that jurisdiction. Therefore, OSHA will also leave the decision as to whether regulated waste treated by a microwave system can be disposed of as regular waste to state and local authorities.

If use of such a system is in accordance with applicable state or local laws, then no apparent violation of 29 CFR 1910.1030(d)(4)(iii) exists. This issue will be revisited in the future when EPA's results are published.

June 15, 1993

                   Director Directorate of Compliance Programs

ATTENTION:          RUTH MC CULLY Director
                   Office of Health Compliance Assistance

THROUGH:            LEO CAREY Director Office of Field Programs

SUBJECT:            Use of Microwave System to Convert Regulated
                   Waste to Regular Trash Free of Biohazardous 

A microwave system is being used by Parkland Hospital, Dallas, Texas, to decontaminate regulated waste. Other hospitals have inquired if this system is acceptable by OSHA for converting regulated waste to regular trash (free of biohazardous materials). Parkland is a county hospital and not under OSHA's jurisdiction; however, they have voluntarily adopted a policy of making every effort to be in compliance with all of OSHA's regulations, including the Bloodborne Pathogens Standard.

Dr. Del Krehbiel, Region VI Bloodborne Pathogens Coordinator, has discussed this system with Laura Lewis who, in turn, discussed it with other members of your staff. Ms. Lewis indicated you would like to review such information before making any comments on its acceptability. Therefore, a copy of the information is attached.

Dr. Krehbiel plans to visit Parkland to observe the operation of this system in the near future and discuss the results experienced with this unit.

If you have any questions about this matter, please contact Jerry Bailey, Assistant Regional Administrator for Technical Support, at 214/767-4734.


Regional Administrator



April 26, 1993

U.S. Department of Labor - OSHA
525 Griffin St.,
Room 602 Dallas, Texas 75202

Attention:   Dr. Del Krehbiel Bloodborne Pathogens Coordinator

Subject:     Regulatory Approval and Efficacy Testing of the ABB Sanitec(TM)
            Disinfection System

Dear Dr. Krehbiel:

I appreciate the opportunity we had to talk on April 26th regarding the ABB Sanitec(TM) System installed at Parkland Memorial Hospital. Parkland is currently processing more than 5,000 pounds per day of their regulated medical waste in this System. This is allowing Parkland to maintain absolute control over the treatment and disposal of the majority of their waste in the healthcare setting without allowing it to be transported off-site for hundreds of miles to be incinerated. In addition, the System performs this treatment without regulated air or liquid emissions, a significant environmental improvement over other technologies.

Per your request, enclosed are regulations or letters from responsible regulatory agencies in the States of Texas, Louisiana, Arkansas, and Oklahoma providing approval of the System for the treatment of regulated medical waste. The System is not currently approved or in use in New Mexico. Also enclosed is a list of the other states in which the system is approved/accepted for use.

Regarding efficacy testing, the System has undergone a number of independent tests in the U.S. and Europe using various test pathogens. Per our discussion, enclosed is a copy of the efficacy test results performed for the State of New York. The standard specified for routine performance testing of the System efficacy, using Bacillus subtilis (niger) spore, is included for your information. B. subtilis is required by the State of Texas, and has been widely approved in other jurisdictions, as the proper test organism for this System (see enclosed letter from Dr. William Rutala and the letter from the State of Connecticut).

If you have any other questions after you review the information, please call me at (817) 370-2426. As we discussed, I am also available to meet with you and visit the installation at Parkland, with their approval.



Robert A. Bollinger President