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NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.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

May 30, 1975

Mr. Len Bower
Loss Control Consultant
Johnson and Higgins of Arizona
Suite 1104 3003 N Central Avenue
Phoenix, Arizona 85012

Dear Mr. Bower:

This is in reply to our telephone conversation of May 22, 1975 requesting an additional interpretation of spray finishing operations as it relates to fire protection systems.

Section 1910.107(b)(5)(iv) requires that the space on the downstream and upstream sides of the filters within spray booths shall be protected with approved automatic sprinklers. Our interpretation of this standard is as follows:

1. Field Information Memorandum (FIM) #75-26 states that a dry chemical extinguishing system installed so as to conform to 1910.160 or a carbon dioxide system installed so as to conform to 1910.161 (see the enclosed copy) may be used in place of an automatic sprinkler system.

2. The purpose of this standard is to provide an automatic extinguishing system for the filter media. The upstream and downstream protection is meant to cover both sides of the filter media and not the entire booth or duckwork. However, 1910.107(f)(1) says that in sprinklered buildings, the entire spray booth has to be sprinklered and in unsprinklered buildings where there is at least one sprinkler head in a booth, the "sprinkler heads shall be located to effect water distribution throughout the entire booth." If a dry chemical or a carbon dioxide system is installed, it would also have to distribute its extinguishing material throughout the entire booth.

3. If the filter media is removed and baffle plates installed, an automatic extinguishing system is not required by this particular standard. The Environment Protection Agency (EPA) regulations should be checked into however, since OSHA only has jurisdiction over employee protection.

4. The National Fire Protection Association (NFPA) 33-1973 requires all spraying areas to be protected with an approved automatic fire extinguishing system. We are proposing in our latest draft of 1910.107 to require an automatic extinguishing system in all spray booths where employees are required to be inside of during spraying operations. This would exclude bench type booths and most of the automatic type booths.

In conclusion, if the building is sprinklered, or dry filters or filter rolls are used, or there is at least one fixed automatic extinguishing system head or nozzle in the booth, or fixed electrostatic apparatus is being used, or organic peroxides or other dual components coatings being used, the entire spray booth must be protected by a fixed extinguishing system, and the revision of 1910.107 may require automatic extinguishing systems in almost all spray booths.

If you have any further questions, please do not hesitate to contact me.


Terence P. Smith
Safety Specialist