Archive Notice - OSHA Archive

NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.

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

August 25, 1994

Mr. Ross Saxon,
Executive Director Association of Diving Contractors, Inc.
2611 FM 1960 West, Suite F-204
Houston, Texas 77068

Dear Mr. Saxon:

This is in response to the Association of Diving Contractors, Inc. (ADC), request for clarification of the requirements of 29 CFR 1910.430(b). Both the ADC Technical Committee and the ADC Safety, Medical and Education Committee requested a compliance determination regarding whether detector tube test kits can be used to satisfy the requirements of 29 CFR 1910.430(b)(3) and (4), which require that the diving compressor output air be tested every six months for carbon monoxide, carbon dioxide and oil mist contaminants.

The use of detector tubes to perform the required sampling, 29 CFR 1910.430(b)(3) and (4), is acceptable provided that the manufacturer's instructions and limitations are followed, and employers comply with the recordkeeping requirements of 1910.440(b)(2) and (b)(3)(vi). Enclosed is a copy of Appendix 1-A "Detector Tubes/Pumps" of the OSHA Technical Manual, OSHA Instruction CPL 2-2.20B CH-1, which provides additional guidance concerning the acceptable use and known limitations of detector tubes. Where such limitations exist, detector tubes may not be used, and alternative acceptable methods shall be employed.

Employers are encouraged to periodically send compressor air samples to laboratories for analysis in order to validate the results of detector tube testing, and to conduct diver's air sampling on a more frequent basis than semi-annually.


Roy F. Gurnham, P.E.,
J.D. Director Office of Construction and Maritime Compliance Assistance