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.

May 17, 1976

Mr. A. L. Wilson
Caterpillar Tractor Company
Peoria, Illinois 61629

Subject: Electrostatic Paint Spraying - 1910.94 & 1910.107

Dear Mr. Wilson:

The minimum maintained velocity required for hand held electrostatic paint spray guns is 60 LFM or more depending on the volume of the finishing material and its flammability and explosion characteristics. This is stated in 1910.107(b)(5)(i). This agrees with range of 50-75 LFM required in Table G-10, 1910.94(c)(6)(i).

1910.107(b)(5)(i) applies to dry systems since the factor of resistance to air flow is much greater through a filter which plugs easily in contrast to a water curtain.

Standard 1910.107 takes precedence over 1910.94. Standard 1910.94 refers to 1910.107 for design and construction of spray booths.

Standard 1910.107 is currently being rewritten to be more comprehensive and the portion in 1910.94 pertaining to spray finishing may be deleted.

Please feel free to contact this office should you have additional questions pertinent to this matter.

Very truly yours,

Assistant Regional Administrator
for Technical Support