San Luis Obispo County Air Pollution Control District


(Adopted 6/8/81; Revised 1/10/89)

A. This Rule is applicable to any person who applies or specifies the use of surface coatings to metal parts and products.

  1. A person shall not use, apply, or specify any coating for use on any metal part or product subject to the provisions of this Regulation which contains volatile organic compounds in excess of the following limits, as applied:

VOC Limitation

Grams Of VOC Per Liter Of Coating

Applied, Excluding Water And Exempt Compounds*


Air Dried


g/l (lb/gal) g/l (lb/gal)
a) General 340 (2.8) 275 (2.3)
b) Military Specification 340 (2.8) 275 (2.3)
c) Metallic 420 (3.5) 360 (3.0)
d) Zinc Filled Primers 420 (3.5) 420 (3.5)
e) Etching filler 720 (6.0) 720 (6.0)
f) Solar-Absorbent 420 (3.5) 366 (3.0)
g) Heat-Resistant 420 (3.5) 360 (3.0)
h) Extreme-High Gloss 420 (3.5) 360 (3.0)
i) Extreme-Performance 420 (3.5) 360 (3.0)
j) Prefabricated Architectural Component 420 (3.5) 275 2.3
k) Touch-up 420 (3.5) 360 (3.0)
l) Repair 420 (3.5) 360 (3.0)
m) Silicone Release 420 (3.5) 420 (3.5)
n) High-performance Architectural 750 (6.3) 720 (6.0)
o) Camouflage 420 (3.5) 360 (3.0)
p) Vacuum-metalizing 800 (6.7) 800 (6.7)
q) Mold Seal 750 (6.3) 720 (6.3)
r) High-temperature 720 (6.0) 720 (6.0)
s) Electric Insulating Varnish 620 (5.2) 620 (5.2)

* Grams of VOC Per Liter of Coating, Excluding Water and Exempt Compounds =

  1. Except as otherwise provided in Section B, a person shall not use or operate any coating application equipment subject to the provisions of this Regulation unless the coating is applied by use of one of the following (properly operating) methods:

  2. a) electrostatic application, or

    b) flow coat, or

    c) dip coat, or

    d) high-volume low-pressure, or

    e) such other coating application methods as are demonstrated to be capable of achieving at least 65 percent transfer efficiency and for which written approval of the APCO has been obtained.

  3. Solvent Disposal and Clean-up Requirements

  4. a) Surface Preparation, Clean-up Or Coating/Ink Paint Removal: A person shall not use other than closed containers for the storage or disposal of cloth or paper impregnated with organic compounds.

    b) Closed containers: A person shall not store spent or fresh organic compounds in other than closed containers.

    c) Spray Equipment Clean-up Limitation: A person shall not use organic compounds for the clean-up of spray equipment, unless equipment for collecting the cleaning compounds and minimizing the evaporation of those compounds to the atmosphere is used.


  1. The provisions of this Rule shall not apply to:

  2. a) Any coating used in volumes of less than 20 gallons in any calendar year, provided that the source demonstrates that no complying coatings are available. Written approval must be obtained from the District.

    b) Aircraft or Aerospace vehicle coating operations.

    c) Marine Vessel Exteriors (below water-line).

    d) Automobile refinishing.

    e) Pretreatment wash primer.

    f) Stationary sources using not more than four (4) gallons of paint, varnish, lacquer, thinner, and other solvent containing materials in any one day and not more than one (1) gallon per hour, provided the recordkeeping requirements at Section C.1 and Section C.2 of this Rule are satisfied.

    g) Stationary sources electing to utilize control equipment demonstrated to the satisfaction of the APCO to effect the same or greater emission reduction as would compliance with this rule. Emissions, for the purpose of this exemption, shall be calculated on an hourly basis.

  3. The provisions of Subsection A.2 shall not apply to:

  4. a) Any coating operation where it can be demonstrated to the satisfaction of the APCO that a transfer efficiency of 65% cannot be achieved. In such case, the most efficient transfer method shall be used.

    b) Metallic coatings which contain more than 30 grams of metal particles per liter of coating as applied.

  5. Any coating subject to the requirements of this Rule shall be exempt from the requirements of Rule 407 except for Sections A.1.g, recordkeeping requirements for solvents, and A.4, Disposal and Evaporation of Solvents.


    Any person subject to the requirements of this Rule and subject to District permits shall have coating manufacturer specification sheets available for review and shall maintain records which show, on a daily basis, the following for each coating:

    a) The amount and type of coating used by each piece of application equipment.

    b) The amount of VOC in each coating and the volume of each coating at the time of application.

    c) The amount of solvent and exempt compound used.

    d) The VOC content of each solvent.

    e) The method of application.

  1. Such records shall be maintained for a minimum of 2 years and be available for inspection by the APCD.


  1. "Air Dried Coating": Means a coating that is cured at a temperature below 194 degrees F (90 degrees C).

  2. "Baked Coating": Means a coating that is cured at a temperature at or above 194 degrees F (90 degrees C).

  3. "Camouflage Coating": Means a coating used, principally by the military, to conceal equipment from detection.

  4. "Electric-Insulating Varnish": Means any coating applied to electric motors, components of electric motors, or to electrical transmission wire.

  5. "Etching Filler": Means a coating that contains less than 23 percent solids by weight and at least 1/2 percent acid by weight, and is used instead of applying a pretreatment coating followed by a primer.

  6. "Exempt Compounds": Means any of the following compounds: methane, 1,1,1-trichloroethane, carbonic acid, metallic carbides or carbonates, and ammonium carbonate as determined by an ARB-approved reference test method.

  7. "Extreme High Gloss Coating": Means a coating which, when tested by the ASTM test method D-523 adopted in 1980, shows a reflectance of 75 or more on a 60 degree meter.

  8. "Extreme-Performance Coating": Means a coating used on a metal surface where the coating is, in its intended use, exposed to any of the following:

  9. a) Industrial-grade detergents, cleaners, abrasive scouring agents, solvents, strong chemical agents, or petrochemical materials; or

    b) Unprotected shipboard conditions; or

    c) Water, waste water, or sewage; or

    d) Other similar environmental conditions as determined by the APCO.

  10. "Heat-Resistant Coating": Means a coating that must withstand a temperature of at least 400 degrees F (204 degrees C) during normal use.

  11. "High-Performance Architectural Coating": Means a coating used to protect architectural subsections and which meets the requirements of the Architectural Aluminum Manufacturers Association's publication number AAMA 605.2-1980.

  12. "High Temperature Coating": Means a coating that is certified to withstand a temperature of 1000 degrees F (538 degrees C) for 24 hours.

  13. "High-Volume Low-Pressure": Means a turbine spray application system which operates at a gun pressure of 0.1 to 10 PSIG.

  14. "Metal Parts and Products": Include any metal parts or products except for those specified in Section B.

  15. "Metallic Coating": Means any coating except zinc filled primer which contains 5 grams or more of metal particles per liter of coating as applied.

  16. "Mold-Seal Coating": Means the initial coating applied to a new mold or a repaired mold to provide a smooth surface which, when coated with a mold release coating, prevents products from sticking to the mold.

  17. "Prefabricated Architectural Component Coatings": Means coatings applied to metal parts and products which are to be used as an architectural structure.

  18. "Pretreatment Wash Primer": Means any coating which contains a minimum of 1/2 % acid by weight applied directly to bare metal surfaces and which is necessary to provide surface etching.

  19. "Repair": Means recoating portions of previously coated product due to mechanical damage to the coating following normal painting operations.

  20. "Silicone-Release Coating": Means any coating which contains silicone resin and is intended to prevent food from sticking to surfaces such as baking pans.

  21. "Solar-Absorbent Coating": Means a coating which has as its prime purpose the absorption of solar radiation.

  22. "Touch Up": Means that portion of the coating operation which is incidental to the main coating process, but necessary to cover minor imperfections or to achieve coverage as required.

  23. "Transfer Efficiency": Means the ratio of the amount by volume of coating which is deposited on the object to be coated to the amount by volume of coating sprayed expressed as a percentage.

  24. "Vacuum-Metalizing Coating": Means the undercoat applied to the substrate on which the metal is deposited or the overcoat applied directly to the metal film.

  25. "Volatile Organic Compound (VOC)": Means any organic compound containing at least one atom of carbon, excluding exempt compounds.

  26. "Zinc Filled Primer": Means any coating which has an elemental zinc content of not less than 240 grams/liter (2.0 pounds/gallon) of coating as applied.


  1. Coating solvent content shall be determined using EPA reference method 24 or its equivalent.