Representative methylene chloride exposure sampling across sites

October 13, 1998
Mr. Frank A. White
Vice President
Organization Resources Counselors, Inc.
[Recipient address omitted]
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 [the Office of Health Enforcement at (202) 693-2190].
Sincerely,
Richard E. Fairfax
Acting Director
Directorate of Compliance Programs

[Corrected 12/6/2024]