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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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§5456. Drying, Curing or Fusion Apparatus.

(a) Drying, curing or fusion apparatus in connection with spray application of flammable and combustible coatings shall conform to the Standard for Ovens and Furnaces, NFPA No. 86A1977, where applicable and shall also conform to the following subsections.

(b) Spray booths, rooms or other enclosures used for spraying operations shall not alternately be used for the purpose of drying by any arrangement which will cause a substantial increase in the surface temperature of the spray booth, room or enclosure.

(c) Except as specifically provided in (d), drying, curing or fusion units utilizing a heating system having open flames or which may produce sparks shall not be installed in a spraying area, but may be installed adjacent thereto when equipped with an interlocked ventilating system arranged to:

(1) Thoroughly ventilate the drying space before heating system can be started;

(2) Maintain a safe atmosphere at any source of ignition;

(3) Automatically shut down heating system in the event of failure of the ventilating system.

(d) When automobile refinishing spray booths or enclosures are used for drying using portable electrical infrared drying apparatus, the following shall apply:

(1) Interior (especially floors) of spray enclosures shall be kept free of overspray deposits.

(2) During spray operations, the drying apparatus and electrical connections and wiring thereto shall not be located within spray enclosure nor in any other location where spray residue may be deposited thereon.

(3) Spraying apparatus, drying apparatus, and ventilating system of spray enclosure shall be equipped with suitable interlocks so arranged that:

(A) Spraying apparatus cannot be operated while drying apparatus is inside spray enclosure.

(B) Spray enclosure will be purged of spray vapors for a period of not less than three minutes before drying apparatus can be energized.

(C) Ventilating system will maintain a safe atmosphere within the enclosure during the drying process and drying apparatus will automatically shut off in the event of failure of the ventilating system.

(4) All electrical wiring and equipment of drying apparatus shall conform to the applicable sections of the Electrical Safety Orders. Only equipment approved for Class I, Division 2 locations shall be located within 18 inches of floor level. All metallic parts of drying apparatus shall be electrically bonded and grounded.

(5) Drying apparatus shall contain a prominently located permanently attached warning sign indicating that ventilation shall be maintained during the drying period and spraying shall not be so conducted in the vicinity that spray will deposit on apparatus.

(e) Fusion facilities shall be ventilated.

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


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

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