Compressed air pressure for cleaning

Dec. 6, 1985
Dr. George J. Reilly
Coordinator and Head, Scientific Research
Winterthur Museum & Gardens
[Recipient address omitted]
Dear Dr. Reilly:
Acting Assistant Secretary Patrick R. Tyson has asked me to respond to your letter dated November 25, requesting a permanent variance from Section 1910.242(b), Compressed air used for cleaning, of the Occupational Safety and Standards.

The enclosed copy of the OSHA Instruction STD 1-13.1 describes the intent and application of this standard. In short, the use of compressed air for cleaning purposes at pressures at or greater than 30 psi is permissible if the outlet or source is fitted with a relief device that drops the pressure to less than 30 psi if the flow is dead-ended. Appropriate personal protective equipment shall be worn as called for in the standard.
You will have to evaluate your procedures in terms of this directive. If I can be of any further assistance, please contact me at (202) 523-7193.
A variance from Section 1910.242(b) is unnecessary, therefore, no further action will be taken on your application.
Sincerely,
James J. Concannon
Director
Office of Variance Determination
Enclosure

[Requester letter and exhibit reproduced on OSHA page; omitted here.]