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 http://www.osha.gov.



October 13, 1998

Mr. Jonathan M. Crotty
Parker, Poe, Adams & Bernstein L.L.P.
2500 Charlotte Plaza
Charlotte, NC 28244

Dear Mr. Crotty:

This is in response to your April 3, letter requesting clarification on the Occupational Safety and Health Administration's (OSHA's) 13 Carcinogens Standard (29 CFR 1910.1003). Please accept our apology for the delay in responding.

Specifically, you inquired as to what type of respiratory protection is needed during routine or controlled maintenance, repair or construction work on (i) equipment used to process dichlorobenzidine (DCB) or (ii) equipment in a regulated area that is not used to process DCB, but that may have been exposed to DCB from processes in the area. For the latter, you gave the example of a water pipe that could have DCB residue on the outside of the pipe. For maintenance or repair operations on equipment contaminated with DCB, air supplied respirators are required. Air supplied respirators are needed because it is expected that the employee will come into contact with the carcinogen while conducting maintenance and repairs on equipment used to process DCB or equipment contaminated with DCB.

Your letter suggested that employees could wear filter-type air purifying respirators if the equipment was emptied, isolated, and flushed. Unless this equipment is effectively decontaminated, the standard allows for no reduction in respiratory protection. Once the material has been decontaminated, respiratory protection is not required. The standard was written to obtain the lowest exposure feasible to DCB.

The State of North Carolina operates its own occupational safety and health program under a plan approved and closely monitored by federal OSHA. The program is operated by the North Carolina Department of Labor, which is primarily responsible for enforcement of OSHA standards in North Carolina. North Carolina must adopt standards at least as protective as federal OSHA's. If you wish to pursue this matter further with the State of North Carolina, you may contact:



Harry Payne, Commissioner
North Carolina Department of Labor
319 Chapanoke Road
Raleigh, NC 27603
(919) 662-4575

If you feel that the circumstances at your client's particular worksite would not permit the use of supplied air respirators and that your client can provide equivalent protection for affected employees, an application for a permanent variance may be appropriate. Information on variance procedures can be obtained from the North Carolina Department of Labor. If your client has establishments in more than one state, your client may want to seek information on variances from the Office of Variance Determination in the Directorate of Technical Support at (202) 219-7193.

Should you require any additional information on this matter, please, feel free to contact our Office of Health Compliance Assistance at (202) 219-8036. Thank you for your patience and your interest in safety and health issues.


Richard E. Fairfax
Acting Director
Directorate of Compliance Programs