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. Frank A. White
Vice President
Organization Resources Counselors, Inc.
1910 Sunderland Place, N.W.
Washington, D.C. 20036-1608

Dear Mr. White:

This is in response to your letter of July 8, 1997, addressed to former Acting Assistant Secretary Gregory Watchman, concerning the "representative sampling" provisions of the Methylene Chloride Standard, 29 CFR 1910.1052. Our response is delayed because we misplaced your letter. Please accept our apology.

You inquired as to whether it is permissible for an employer with similar manufacturing work sites to perform representative employee exposure sampling for a job classification at one site and apply the results to the exposures of employees with the same job classifications performing the same duties at the other sites.

Such application of employee exposure results does not conform with 29 CFR 1910.1052(d)(1)(ii)(A) or (B) because it entails using the exposure results for an employee in one work area to represent the exposures of employees in other work areas. Title 29 CFR 1910.1052(d)(1)(ii)(A) and (B) both indicate that one of the conditions in order for an air sample to be representative of an employee's exposure is that the sample must be taken in the area where the employee works.

We appreciate the opportunity to clarify this matter for you. If you have further questions you may contact our Office of Health Compliance Assistance at (202) 219-8036.


Richard E. Fairfax
Acting Director
Directorate of Compliance Programs