Standard Interpretations - Table of Contents
• Standard Number: 1926.302(b)(4); 1926.405(a)(2); 1926.405(a)(2)(ii)(B)

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

October 4, 2000

Joy C. DesRosier, ASP COHN-SM
Senior Safety Consultant
Argonaut Insurance Company
Financial Plaza, Suite 850
6900 College Boulevard
Overland Park, Kansas 66211

Re: Interpretations of 29 CFR 1926.302(b)(4) and 1926.405(a)(2)

Dear Ms. DesRosier:

Thank you for your letter of October 12, 1999, in which you requested clarification of OSHA standards that regulate use of compressed air for cleaning and electrical installations and equipment. We apologize for the delay in providing this response.

Using compressed air to clean concrete form and mill scale

Questions: Section 1926.302(b)(4) provides that "compressed air shall not be used for cleaning purposes except where reduced to less than 30 p.s.i. and then only with effect