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.



August 28, 1991

K.C. Potter
Paducah Gaseous Diffusion Plant
P.O. Box 1410
Paducah, KY 42001

Dear Mr. Potter,

This letter is in response to your letter of July 15, 1991. You have asked what limit to report for asbestos analysis, the quantitation limit or the detection limit.

The analytical laboratory should report what it sees within the constraints of the method used. Concentrations below the detection limit are none detected. Other values above that are reported as analyzed. There is no special requirement for results between the detection limit and any quantitation limit. The OSHA Salt Lake Technical Center reports "0.0" for results below the detection limit and the actual result for values greater than the detection limit with no comment otherwise.

For your information, a copy of the OSHA method ID 160 has been included. Should you have further question, do not hesitate to call.


Daniel T. Crane
Supervisory Physical Scientist
[(801) 233-4900]



July 15, 1991

Mr. Daniel Crane, Supervisory Physical Scientist
OSHA Salt Lake Technical Center
[8660 South Sandy Parkway
Sandy, UT 84070-6424]

Dear Mr. Crane:

Reporting Limits for Asbestos Air Concentrations

Per our recent telephone conversation, I am writing to request written guidance from the Occupational Safety and Health Administration regarding reporting limits for asbestos air concentrations. There seems to be some discrepancy about which reporting limit should be used: (1) limit of detection, or (2) limit of quantitation. Guidance from your agency on this issue would be greatly appreciated.

Please forward your response to K. C. Potter, Paducah Gaseous Diffusion Plant, Post Office Box 1410, Paducah, Kentucky 42001. Thank you in advance for your assistance.


K. C. Potter, Industrial Hygienist
Paducah Gaseous Diffusion Plant

[Correction 2/13/04]