(1) Electrical and other sources of ignition. Electrical equipment and other sources of ignition must conform to the requirements of WAC 296-24-37005 and chapter 296-24 WAC Part L.

(2) Ventilation.

(a) In addition to the provisions of WAC 296-24-37007, where applicable, exhaust ventilation must be sufficient to maintain the atmosphere below the lowest explosive limits for the materials being applied. You must safely remove all nondeposited air-suspended powders via exhaust ducts to the powder recovery cyclone or receptacle. You must design and operate each installation to meet the foregoing performance specification.

(b) You must not release powders to the outside atmosphere.

(3) Drying, curing, or fusion equipment. The provisions of the Standard for Ovens and Furnaces, NFPA No. 86A-1969 must apply where applicable.

(4) Operation and maintenance.

(a) You must keep all areas free of the accumulation of powder coating dusts, particularly such horizontal surfaces as ledges, beams, pipes, hoods, booths, and floors.

(b) You must clean surfaces in such manner as to avoid scattering dust to other places or creating dust clouds.

(c) You must conspicuously post "No smoking" signs in large letters on contrasting color background at all powder coating areas and powder storage rooms.

(5) Fixed electrostatic spraying equipment. The provisions of WAC 296-24-37015 and other subsections of this section must apply to fixed electrostatic equipment, except that electrical equipment not covered therein must conform to (1) of this section.

(6) Electrostatic hand spraying equipment. The provisions of WAC 296-24-37017 and other subsections of this section, must apply to electrostatic handguns when used in powder coating, except that electrical equipment not covered therein must conform to (1) of this section.

(7) Electrostatic fluidized beds.

(a) Electrostatic fluidized beds and associated equipment must be of approved types. The maximum surface temperature of this equipment in the coating area must not exceed 150°F. You must design the high voltage circuits so as to not produce a spark of sufficient intensity to ignite any powder-air mixtures nor result in appreciable shock hazard upon coming in contact with a grounded object under normal operating conditions.

(b) You must locate transformers, powerpacks, control apparatus, and all other electrical portions of the equipment, with the exception of the charging electrodes and their connections to the power supply outside of the powder coating area or they must otherwise conform to the requirements of (1) of this section.

(c) You must adequately ground all electrically conductive objects within the charging influence of the electrodes. The powder coating equipment must carry a prominent, permanently installed warning regarding the necessity for grounding these objects.

(d) You must maintain objects being coated in contact with the conveyor or other support in order to insure proper grounding. You must regularly clean hangers to ensure effective contact and areas of contact must be sharp points or knife edges where possible.

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

PDFWAC 296-24-37023

Powder coating.