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Subchapter 7. General Industry Safety Orders
Group 20. Flammable Liquids, Gases and Vapors
Article 137. Spray Coating Operations

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§5446. Spray Booths.

(a) Spray booths and connected ductwork shall be substantially constructed of steel, securely and rigidly supported, or of concrete or masonry, except that aluminum or other substantial noncombustible material may be used for intermittent or low volume spraying. Spray booths shall be designed to sweep or guide air currents toward the exhaust outlet.

(b) The interior surfaces of spray booths shall be smooth and continuous without edges and otherwise designed to prevent pocketing of residues and facilitate cleaning and washing without injury.

(c) The floor surface of a spray booth and operator's working area, if combustible, shall be covered with noncombustible material of such character as to facilitate the safe cleaning and removal of residues.

(d) Distribution or baffle plates, if installed to promote an even flow of air through booth or cause the deposit of overspray before it enters exhaust duct, shall be of noncombustible material and readily removable or accessible on both sides for cleaning. Such plates shall not be located in exhaust ducts.

(e) Every spray booth having an open front elevation larger in area than 9 square feet and which is not equipped with doors, shall have a fire curtain or metal deflector not less than 2 1/2 inches deep installed at the upper outer edge of the booth opening.

(f) Where conveyors are arranged to carry work into or out of spray booths, the openings therefor shall be as small as practical.

(g) Each spray booth shall be separated from other dissimilar operations by not less than three feet, or by a greater distance, or by such partition or wall as to reduce the danger from adjacent hazardous operations.

(h) Spray booths shall be so installed that all portions are readily accessible for cleaning. A clear space of not less than three feet on all sides shall be kept free from storage or combustible construction.

NOTE: This does not preclude the installation of a spray booth against a partition or wall having a one hour fire resistance rating providing the booth can be maintained and cleaned.

NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.


1. Amendment filed 7-16-76; effective thirtieth day thereafter (Register 76, No. 29).

2. Amendment of subsection (h) filed 12-5-86; effective thirtieth day thereafter (Register 86, No. 51).

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