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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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§5460. Powder Coating.

(a) This section shall apply to processes in which combustible dry powders are applied such as:

(1) Fluidized bed.

(2) Electrostatic fluidized bed.

(3) Powder spray guns.

(4) Electrostatic powder spray guns.

(b) Powder coating operations shall be confined to properly designed enclosures protected with automatic fire extinguishing systems.

(c) Powder shall be effectively confined by conducting coating operations within:

(1) Completely enclosed, adequately ventilated rooms of noncombustible construction with smooth surfaces designed to prevent accumulation of powder and to facilitate cleaning, or

(2) Adequately ventilated spray booths and by using effectively enclosed, adequately ventilated containers (tanks, bins, etc.) of noncombustible material.

(d) Electrical equipment shall conform to the requirements of the Electrical Safety Orders.

(e) Powder transport, application and recovery equipment shall be grounded.

(f) Ventilation requirements shall conform to the provisions of Section 5153 and 5143.

(g) All areas including horizontal surfaces such as ledges, beams, pipes, hoods and booth floors shall be periodically cleaned to prevent the accumulation of powder.

(h) Surfaces shall be cleaned in such manner as to avoid scattering powder or creating powder clouds. Vacuum sweeping equipment where used, shall be of a type approved for use in hazardous locations.

(i) Care shall be exercised to prevent tramp iron or spark producing material from being introduced into the powders being applied. Magnetic and filter type separators are recommended.

(j) Smoking shall be prohibited except in designated localities. "NO SMOKING" signs shall be conspicuously posted where hazard from flammable vapors or combustible powders are normally present.

(k) The provisions of Section 5454 and this section shall apply to fixed electrostatic equipment, except that electrical equipment not covered therein shall conform to (d) and (e) of this Section.

(l) The provisions of Section 5455 and this Section shall apply to electrostatic hand guns when used in powder coating.The high voltage circuits shall be designed so as not to produce a spark of sufficient intensity to ignite any powder-air mixtures likely to be encountered. The electrical equipment not covered by Section 5455 shall comply with (d) and (e) of this Section.

(m) Electrostatic fluidized beds and associated equipment shall be of approved types. The high voltage circuits shall be so designed that any discharge produced when the charging electrodes of the bed are approached, or contacted by a grounded object shall not be of sufficient intensity to ignite any powder-air mixture likely to be encountered, nor result in an appreciable shock hazard.

(n) Transformers, high voltage supply, control apparatus and all other electrical portions of the equipment, with the exception of the charging electrodes and their connections to the power supply shall be located outside of the powder coating area or shall otherwise conform to the requirements (d) and (e) of this Section.

(o) All electrically conductive objects within the powder coating area shall be grounded. The powder coating equipment shall carry a prominent, permanently installed warning regarding the necessity for grounding these objects.

(p) Objects being coated shall be maintained in electrical contact with the conveyor or other support in order to insure proper grounding. Hangers shall be regularly cleaned to insure effective contact and areas of contact shall be sharp points or knife edges where possible.

(q) The electrical equipment shall be so interlocked with the ventilation system that the equipment cannot be operated unless the ventilation fans are in operation.

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 filed 12-5-86; effective thirtieth day thereafter (Register 86, No. 51).

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