Imperial County Air Pollution Control District Rule 101

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RULE 101 DEFINITIONS

(Adopted 7/28/81; Revised 9/14/99; 1/16/2001; 12/11/2001; 08/13/02; 

01/11/2005; 10/10/2006; 02/23/2010; 10/22/2013; 2/9/2016)

Except where the context otherwise indicates, the following definitions shall govern the 

implementation of these Rules and Regulations. Also, pursuant to Rule 115, definitions 

contained in applicable sections of the California Health and Safety Code and Title 17 of 

the California Code of Regulations, as well as the Federal Clean Air Act and 

implementing regulations, may be used even when not set forth herein.

ACCELERATED VEHICLE RETIREMENT PROGRAM: a program creating Actual 

Emission Reductions by the accelerated retirement of on-road motor vehicles for 

purposes of establishing Mobile Source Emission Reduction Credits (MSERC) pursuant 

to Rule 214.1. 

ACTUAL EMISSIONS: measured or calculated emissions which most accurately 

represent the emissions from an Emissions Unit. Determination of Actual Emissions 

must be based on average actual production rates, fuel consumption and/or throughput 

rates from the last consecutive 24 months. Emission factors shall be established by

Source testing or obtained from AP-42 or other approved sources.

ACTUAL EMISSIONS REDUCTIONS (AER): reductions of Actual Emissions from an 

Emissions Unit, calculated pursuant to Section E.2 of Rule 207, which are Real, 

Quantifiable, Surplus, Permanent and Enforceable.

ACTUAL INTERRUPTIONS OF POWER: the interruption of electrical service by an 

unforeseeable event.

ADDITIVE: any substance added in small quantities to another substance or mixture in 

order to increase volume and/or change the physical properties of the mixture.

ADHESION PROMOTER: a Coating, which is labeled and formulated to be applied to 

uncoated plastic surfaces to facilitate bonding of subsequent Coatings, and on which, a 

subsequent Coating is applied.

ADHESIVE: any chemical substance that is applied for the purpose of bonding two 

surfaces together other than by mechanical means.

ADHESIVE BONDING PRIMER: a Coating applied in a very thin film to aerospace 

adhesive bond detail components for corrosion inhibition and adhesion of the 

subsequently applied adhesive.

ADHESIVE BONDING PRIMER, STRUCTURAL: an adhesive bonding primer used in 

conjunction with structural adhesives to form load carrying aircraft components.
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ADHESIVE BONDING PRIMER FOR ELASTOMERS AND ELASTOMERIC 

ADHERENTS: an adhesive bonding primer applied to elastomers or nonmetallic 

substrates for adhesion of the subsequently applied adhesive.

ADMINISTRATOR: the Administrator of the United States Environmental Protection 

Agency (US EPA).

AEROSPACE COMPONENT: any fabricated part, assembly of parts or completed unit 

of any aircraft, helicopter, missile or space vehicle.

AEROSOL COATING PRODUCT: a pressurized Coating product containing pigments 

or resins that dispenses product ingredients by means of a propellant, and is packaged 

in a disposable can for hand held application, or for use in specialized Equipment for 

ground traffic/marking applications.

AFFECTED POLLUTANTS: pollutants for which an Ambient Air Quality Standard 

(AAQS) have been established by the United States Environmental Protection Agency

(US EPA) or the California Air Resources Board (CARB) and the Precursors to such 

pollutants, and those pollutants regulated by the US EPA under the Clean Air Act (CAA)

or by the CARB under the Health and Safety Code (H&SC), except for greenhouse 

gases and hazardous air pollutants, including but not limited to Volatile Organic 

Compounds (VOC), nitrogen oxides (NOx), sulfur oxides (SOx), Particulate Matter with 

an aerodynamic diameter equal to or less than 10 micrometers (PM10), Particulate 

Matter with an aerodynamic diameter equal to or less than 2.5 micrometers (PM2.5), 

carbon monoxide (CO), lead, fluorides, sulfuric acid mist, hydrogen sulfide, and total 

reduced sulfur compounds. The term Affected Pollutant shall not include any or all 

hazardous air pollutants either listed in Section 112 of the CAA or added to the list 

pursuant to Section 112(b)(2) of the CAA, and which have not been delisted pursuant to 

Section 112(b)(3) of the CAA, unless the listed hazardous air pollutant is also regulated 

as a constituent or Precursor of a general pollutant listed under Section 108 of the CAA.

AGRICULTURAL BURNING: open outdoor fires used in agricultural operations in the 

growing of crops or raising of fowls or animals, or open outdoor fires used in forest 

management, range improvement, or the improvement of land for wildlife and game 

habitat, or disease or pest prevention.

AGRICULTURAL BURNING: also means open outdoor fires used in the operation or 

maintenance of a system for the delivery of water for the purposes specified above.

AGRICULTURAL BURNING: also means open outdoor fires used in wild land

vegetation management burning. Wild land vegetation management burning is the use 

of prescribed burning conducted by a public agency, or through a cooperative 

agreement or contract involving a public agency, to burn land predominantly covered 

with chaparral, trees, grass, or standing brush. Prescribed burning is the planned 

application of fire to vegetation to achieve any specific objective on lands selected in 

advance of that application. The planned application of fire may also include natural or 
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accidental ignition.

AGRICULTURAL SOURCE: means a Source of air pollution or a group of Sources used 

in the production of crops, or the raising of fowl or animals located on Contiguous 

Property under common ownership or control that meets any of the following criteria;

1. is a Confined Animal Facility, including, but not limited to, any structure, building, 

installation, barn, corral, coop, feed storage area, milking parlor, or system for the 

collection, storage, treatment, and distribution of liquid and solid manure, if 

domesticated animals, including, but not limited to, cattle, calves, horses, sheep, 

goats, swine, rabbits, chickens, turkeys, or ducks are corralled, penned, or 

otherwise caused to remain in restricted areas for commercial agricultural 

purposes and feeding is by means other than grazing.

2. is an Internal Combustion Engine used in the production of crops or the raising of 

fowl or animals, including, but not limited to, an engine subject to Article 1.5 

(commencing with Section 41750) of Chapter 3 of Part 4 of Division 26 of the 

Health & Safety Code except an engine that is used to propel implements of 

husbandry.

3. is a Title V Source, or is a Source that is otherwise subject to regulation by the 

District or the Clean Air Act.

AIR CONTAMINANT: any discharge, release, or other propagation into the Atmosphere 

and includes, but is not limited to, smoke, charred paper, Dust, soot, grime, carbon, 

fumes, gases, odors, Particulate Matter, acids, or any other combination thereof. For the 

purposes of Rule 403, the definition applies only to materials which are solid or liquid at 

Standard Conditions (60 degrees Fahrenheit, 760 mm Hg).

AIR POLLUTION CONTROL OFFICER (APCO): the person appointed by the Air 

Pollution Control Board and assigned to manage and direct the business and operations 

of the District, or their designee.

ALTERNATIVE FUEL: any fuel used for certifying a low emission vehicle, other than 

gasoline or diesel fuel.

ALUMINUM ROOF COATING: a Coating labeled and formulated exclusively for 

application to roofs and containing at least 84 grams of elemental aluminum pigment 

per liter of Coating (at least 0.7 pounds per gallon). Pigment content shall be 

determined in accordance with South Coast Air Quality Management District 

(SCAQMD) Method 318-95, incorporated by reference in Rule 424, subsection G.5.d.

AMBIENT AIR QUALITY STANDARDS: for the purposes of these regulations an

Ambient Air Quality Standard (AAQS) shall be interpreted to include State and National 

AAQS. For the purposes of submittal of this Rule to the US EPA for inclusion in the 

California State Implementation Plan (SIP) all references in this Rule to AAQS shall be 
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interpreted as National AAQS.

ANNUAL CAPACITY FACTOR (ACF): means the ratio of the amount of fuel burned by 

a unit in a calendar year to the amount of fuel it could have burned if it had operated at 

the heat input rating for 8,760 hours during the calendar year.

ANTENNA COATING: a Coating labeled and formulated exclusively for application to 

equipment and associated structural appurtenances that are used to receive or transmit 

electromagnetic signals. Effective January 1, 2011, a Coating meeting this definition 

will be subject to the applicable category in Table 424-2, except as provided in 

subsection D.2, Most Restrictive VOC Limits found in Rule 424.

ANTIFOULING COATING: a Coating labeled and formulated for application to 

submerged stationary structures and their appurtenances to prevent or reduce the 

attachment of marine or freshwater biological organisms. To qualify as an antifouling 

Coating, the Coating must be registered with both the US EPA under the Federal 

Insecticide, Fungicide, and Rodenticide Act (7 United States Code. Subsection 135, et 

seq.) and with the California Department of Pesticide Regulation. Effective January 1, 

2011, a Coating meeting this definition will be subject to the applicable category in 

Table 424-2, except as provided in subsection D.2, Most Restrictive VOC Limits found 

in Rule 424.

ANTI-GLARE/SAFETY COATING: a Coating which does not reflect light.

APPLICATION EQUIPMENT: for the purposes of Rule 425, means Equipment used for 

applying Coating to a substrate. Application Equipment includes Coating distribution 

lines, Coating hoses, equipment used in hand application methods, and equipment 

used in mechanically operated application methods, including but not limited to spray 

guns, spinning disks, and pressure pots.

APPROVED IGNITION DEVICES: includes those instruments or materials that will 

ignite agricultural waste without the production of black smoke by the ignition device. 

This would include such items as liquid petroleum gas, butane, propane, and flares, but 

does not include the use of tires, tar paper, oil, and other similar materials.

APPURTENANCES: any accessory to a stationary structure coated at the site of 

installation, whether installed or detached, including but not limited to: bathroom and 

kitchen fixtures; cabinets; concrete forms; doors; elevators; fences; hand railings; 

heating equipment, air conditioning equipment, and other fixed mechanical equipment 

or stationary tools; lampposts; partitions; pipes and piping systems; rain gutters and 

downspouts; stairways, fixed ladders, catwalks, and fire escapes; and window screens.

ARCHITECTURAL COATINGS: a Coating to be applied to stationary structures or their 

appurtenances at the site of installation, to portable buildings at the site of installation, to 

pavements, or to curbs. Coatings applied in shop applications or to non-stationary 

structures such as airplanes, ships, boats, railcars, and automobiles, and adhesives are 
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not considered Architectural Coatings for the purposes of this Rule.

ASPHALT: the dark-brown to black cementitious material (solid, semi-solid, or liquid in 

consistency) of which the main constituents are b Bitumens which occur naturally or as 

a residue of petroleum refining.

ASSEMBLY LINE: an arrangement of industrial Equipment and workers in which the 

product passes from one specialized operation to another until complete, by either 

automatic or manual means.

ASSOCIATED PARTS AND COMPONENTS: structures, devices, pieces, modules, 

sections, assemblies, subassemblies, or elements of motor vehicles or mobile 

equipment that are designed to be a part of motor vehicles or mobile Equipment but 

which are not attached to motor vehicles or mobile Equipment at the time of Coating the 

structure, device, piece, module, section, assembly, subassembly, or element. 

“Associated Parts and Components” does not include circuit boards.

ATMOSPHERE: the air that envelopes or surrounds the earth. When air pollutants are 

emitted into or within a building, such emission into or within the building shall be 

considered an emission into the Atmosphere unless the building is designed specifically 

as a piece of air pollution control equipment.

AUTHORITY TO CONSTRUCT: a written permit issued by the District for the 

Construction, installation, assembly, Modification, or replacement of any facility, article, 

machine, Equipment, or other contrivance.

AUTOMOTIVE COATING: any Coating or Coating component used or recommended 

for use in Motor Vehicle or Mobile Equipment Refinishing, service, maintenance, repair, 

restoration, or Modification, except metal plating activities. Any reference to automotive 

Refinishing or Automotive Coating made by a Person on the container or in product 

literature constitutes a recommendation for use in Motor Vehicle or Mobile Equipment

Refinishing.

AUTOMOTIVE COATING COMPONENT: any portion of a Coating, including, but not 

limited to, a Reducer or thinner, toner, hardener, and Additive, which is recommended 

by any Person to distributors or end-users for use in an Automotive Coating, or which is 

supplied for or used in an Automotive Coating. The raw materials used to produce the 

components are not considered Automotive Coating Components.

AUTOMOTIVE REFINISHING FACILITY: any shop, business, location, or parcel of land 

where Motor Vehicles or Mobile Equipment or their associated parts and components 

are coated including auto body collision repair shops. “Automotive Refinishing Facility” 

does not include the original Equipment manufacturing plant where the Motor Vehicle or 

Mobile Equipment is completely assembled.
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BANKING: the District's system of quantifying, certifying, recording, and storing 

Emission Reduction Credits for future use or Transfer. This system shall be called 

Emission Reduction Credit Banking or Mobile Source Emission Reduction Credit.

BANKING REGISTER: the document that records all Emission Reduction Credits 

deposits, withdrawals, Transfers, and transactions.

BASEMENT SPECIALTY COATING: a clear or opaque Coating that is labeled and 

formulated for application to concrete and masonry surfaces to provide a hydrostatic 

seal for basements and other below-grade surfaces. Basement Specialty Coatings 

must meet the following criteria:

1. Coating must be capable of withstanding at least 10 psi of hydrostatic pressure, 

as determined in accordance with ASTM D7088-04, which is incorporated by 

reference in Rule 424, subsection G.5.n.

2. Coating must be resistant to mold and mildew growth and must achieve a 

microbial growth rating of 8 or more, as determined in accordance with ASTM 

D3273-00 and ASTM D3274-95, incorporated by reference in Rule 424, 

subsection G.5.t.

BEEF FEEDLOT: a lot, fenced area, or facility used for the feeding or holding of more 

than ten (10) cattle, except for Grazing Land as defined herein.

BEST AVAILABLE CONTROL TECHNOLOGY (BACT): for any Emissions Unit the 

more stringent of:

1. the most effective emission Control Device, emission limit, or technique which has 

been achieved in practice for such class or category of Source.

2. any other alternative emission Control Device, emission control technique, basic 

Equipment, fuel, or process determined to be technologically feasible and 

cost-effective by the APCO. Cost-effectiveness analyses shall be performed in 

accordance with methodology and criteria specified in the Best Available Control 

Technology Guideline for the South Coast Air Quality Management District, or an 

alternative methodology and criteria acceptable to the APCO.

3. under no circumstances shall BACT be determined to be less stringent than the 

emission control required by any applicable provision of law or regulation of the 

District, State and federal government, or the most stringent emissions limitation 

which is contained in the implementation plan of any State, unless the applicant 

demonstrates to the satisfaction of the APCO that such limitations are not 

technologically achievable. In no event shall the application of BACT result in the 

emissions of any pollutant which exceeds the emissions allowed by any applicable 

New Source Performance Standard (40 CFR, part 60) or National Emission 

Standard for Hazardous Air Pollutants (40 CFR, part 61 or part 63).
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BEST AVAILABLE RETROFIT CONTROL TECHNOLOGY (BARCT): the most stringent 

and cost effective of the following control options:

1. the most effective elements of the related suggested control measure.

2. the most effective limits in effect in any regulation in California, in the United 

States, or in any other country for that Source category with such limits resulting 

from the application of retrofit control technologies judged by the APCO to be 

demonstrated and reliable.

3. the most effective limit for Source category determined to a reasonable degree of 

certainty, to be achievable in the near future.

4. any combination of control technologies that will achieve emission reductions 

equivalent to that resulting from the most stringent option listed above.

BIOMASS: material derived from the harvesting of crops or removal of vegetation, 

including timber, except for material from processed dimensional timber.

BITUMENS: black or brown materials including, but not limited to, asphalt, tar, pitch, 

and asphaltite that are soluble in carbon disulfide, consist mainly of hydrocarbons, and 

are obtained from natural deposits or as residues from the distillation of crude petroleum 

or coal.

BITUMINOUS ROOF COATING: a Coating which incorporates Bitumens that is labeled 

and formulated exclusively for roofing.

BITUMINOUS ROOF PRIMER: a Primer which incorporates Bitumens that is labeled 

and formulated exclusively for roofing and intended for the purpose of preparing a 

weathered or aged surface or improving the adhesion of subsequent surfacing 

components.

BOARD: the Air Pollution Control Board of the Imperial County Air Pollution Control 

District.

BOILER OR STEAM GENERATOR: means any combustion Equipment fired with 

gaseous and/or liquid fuel and used to produce steam or to heat water. “Boiler” or 

“Steam Generator” shall not include waste heat recovery Boilers that are used to 

recover heat from the exhaust of Stationary Gas Turbines or Internal Combustion 

Engines, or any unfired waste heat recovery Boiler that is used to recover sensible heat 

from the exhaust of any combustion Equipment.

BOND BREAKER: a Coating labeled and formulated for application between layers of 

concrete to prevent a freshly poured top layer of concrete from bonding to the layer over 

which it is poured.
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BOTTOM LOADED: a Gasoline Delivery Vessel shall be considered to be Bottom 

Loaded when the fuel transfer and vapor return lines have separate, independent, and 

dedicated attachments on the delivery vessel, when the inlet is flush with the bottom of 

the storage device, and when the delivery vessel hatches remain closed during fuel 

transfer.

BREAKDOWN: an unforeseeable failure or malfunction of 1) any air pollution control 

Equipment, or related operating Equipment, which causes a violation of any emission 

limitation or restriction prescribed by these rules and regulations, or by State law, or 2) 

any monitoring Equipment, where such failure or malfunction is not the result of neglect 

or disregard of any air pollution control law or rules or regulations, is not intentional or 

the result of negligence, is not the result of improper maintenance, does not constitute a 

nuisance, and is not a recurrent breakdown of the same Equipment.

BRITISH THERMAL UNIT (Btu): means the amount of heat required to raise the 

temperature of one pound of water from 59F to 60F at one Atmosphere.

BURN DAY: any day on which Agricultural Burning is not prohibited by the Air 

Resources Board and/or the Imperial County Air Pollution Control District.

CALIFORNIA AIR RESOURCES BOARD (CARB): the California Air Resources Board 

or any Person authorized to act on its behalf.

CAMOUFLAGE COATING: a Coating applied on Motor Vehicles, or Mobile Equipment 

to conceal such vehicles or Equipment from detection and/or to provide resistance to 

chemical agents.

CARB CERTIFIED VAPOR RECOVERY SYSTEM: is any Phase I or Phase II Vapor 

Recovery System which has been certified by the California Air Resources Board 

pursuant to Section 41954 of the California Health and Safety Code.

CARGO CARRIERS: Cargo Carriers are trains dedicated to a specific Stationary 

Source. For purposes of this Rule, the term "trains dedicated to a specific Stationary 

Source" shall not include any train for which the prime mover is owned and operated by 

a common carrier, and by which cargo is delivered to or from the Stationary Source 

under a contract of common carriage. The emissions from all trains dedicated to a 

specific Stationary s Source, while operating in the District, including directly emitted 

and Fugitive Emissions, shall be considered as emissions from the Stationary Source.

CATALYST: a substance whose presence initiates/enhances the reaction between 

chemical compounds.

CERTIFICATE: a District issued document specifying information regarding an 

ERC/MSERC/ABERC including but not limited to the legal owner(s), certificate 

identification number, date of issuance, pollutant(s) reduced, type of pollutant, quantity 
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of Actual Emission Reduction, time period for which the ERC/MSERC/ABERC is Valid 

and any other records as may be required as a condition of ERC/MSERC/ABERC

issuance.

CLASS I AREA: any area listed as Class I in 40 CFR Part 81 Subpart D, including 

Section 81.405, or an area otherwise specified as Class I inn the legislation that creates 

a national monument, a national primitive area, a national preserve, a national 

recreational area, a national wild and scenic river, a national wildlife refuge, a national 

lakeshore or seashore.

CLEAN AIR ACT (CAA): the Federal Clean Air Act (42 United States Code section 7401 

et seq.) and implementing regulations. (see also Federal Clean Air Act)

CLEANING OPERATIONS: the removal of loosely held uncured Adhesives, inks, 

Coatings, or contaminants, including, but not limited to, dirt, soil, or grease, from m

Motor Vehicles, Mobile Equipment, associated parts and components, substrates, parts, 

products, tools, machinery, Equipment, or general work areas.

CLEAR BRUSHING LACQUERS: clear wood finishes, excluding clear lacquer sanding 

sealers, formulated with nitrocellulose or synthetic resins to dry by solvent evaporation 

without chemical reaction and to provide a solid, protective film, which are intended 

exclusively for application by brush, and which are labeled as specified in Rule 424, 

subsection E.6. Effective January 1, 2011, a Coating meeting this definition will be 

subject to the applicable category in Table 424-2, except as provided in subsection D.2, 

Most Restrictive VOC Limits found in Rule 424.

CLEAR COATING: any Coating that contains no pigments and is labeled and 

formulated for application over a color Coating or clear Coating.

CLEAR WOOD COATINGS: clear and semi-transparent Coatings, including Lacquers 

and Varnishes, applied to Wood Substrates, to provide a transparent or translucent 

solid film. Effective January 1, 2011, a Coating meeting this definition will be subject to 

the applicable category in Table 424-2, except as provided in subsection D.2, Most 

Restrictive VOC Limits found in Rule 424.

COATING: a material applied onto or impregnated into a substrate for protective, 

decorative, or functional purposes. Such materials include, but are not limited to paints, 

Varnishes, sealers, and Stains. For purposes of Rule 427, Coating shall mean a 

material which is applied to a surface and forms a film in order to beautify, preserve, 

repair, or protect such a surface.

CODE OF FEDERAL REGULATIONS (CFR): the United States document codifying 

federal regulations.

COLD CLEANER: any batch loaded, non-boiling Organic Solvent Degreaser.
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COLORANT: a concentrated pigment dispersion in water, Solvent, and/or binder that is 

added to an Architectural Coating after packaging in sale units to produce the desired 

color.

COLOR COATING: any pigmented Coating, excluding Adhesion Promoters, primers, 

and Multi-Color Coatings, that requires a subsequent Clear Coating and which is 

applied over a Primer, Adhesion Promoter, or Color Coating. Color Coatings include 

metallic/iridescent Color Coatings.

COLOR MATCH: the ability of a repair Coating to blend into an existing Coating so that 

color difference is not visibly detectable.

COMBUSTIBLE REFUSE: any solid or liquid combustible waste material containing 

carbon in a free or combined state. 

COMBUSTION CONTAMINANT: solid or liquid particles discharged into the

Atmosphere from the burning of any kind of material containing carbon in a free or 

combined state.

COMPLETE APPLICATION: completeness of an application for an Authority to 

Construct a new or modified Emissions Unit shall be evaluated on the basis of a list of 

required information which has been adopted by the District.

CONCRETE CURING COMPOUND: a Coating labeled and formulated for application to 

freshly poured concrete to perform one or more of the following functions:

1. retard the evaporation of water; or

2. harden or dustproof the surface of freshly poured concrete.

CONCRETE/MASONRY SEALER: a clear or opaque Coating that is labeled and 

formulated primarily for application to concrete and masonry surfaces to perform one or 

more of the following functions:

1. prevent penetration of water; or

2. provide resistance against abrasion, alkalis, acids, mildew, staining, or ultraviolet 

light; or

3. harden or dustproof the surface of aged or cured concrete

CONDENSER EQUIPMENT: any Equipment, such as refrigerated or non-refrigerated 

freeboard chillers, condenser coils, or water jackets, used to condense Organic Solvent 

vapor in a vapor Degreaser.

CONDENSER FLOW SWITCH: safety switch which shuts off pump heat if condenser 
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water fails to circulate or if condenser water temperature rises above designated 

operating temperature.

CONFINED ANIMAL FACILITY (CAF): a Source or group of Sources of air pollution at 

an Agricultural Source for the raising of fowl or animals, including but not limited to, any 

structure, building, installation, farm, corral, coop, feed storage area, milking parlor, or 

system for the collection, storage, or distribution of solid and liquid manure; if 

domesticated animals, including but not limited to, cattle, calves, horses, sheep, goats, 

swine, rabbits, chickens, turkeys, or ducks corralled, penned, or otherwise caused to 

remain in restricted areas for commercial agricultural purposes and feeding is by means 

other than grazing.

CONSTRUCTION: any physical change or change in the method of operation (including 

fabrication, erection, installation, demolition, or Modification of an Emissions Unit) which 

would result in a change in emissions.

CONTAMINATED SOIL: for purposes of Rule 412, soil which indicates 50ppm by 

volume, or greater of ROC (measured as hexane) at a distance of three inches above 

the surface with a ROC analyzer.

CONTIGUOUS PROPERTY: two or more Parcels of land with a common boundary or 

separated solely by a public or private roadway or other public right-of-way.

CONTROL DEVICE: any device for reducing emissions into the Atmosphere.

CONTROL EFFICIENCY: the percentage of emissions removed by an existing emission

Control Device or estimated to be removed by a proposed emission Control Device. The 

estimated control efficiency of the proposed air pollution control technology which will be 

incorporated, by means of Enforceable permit condition(s), in the Authority to Construct 

and Permit to Operate. Emission reductions attributed to lowering throughput rates or 

operating reductions attributed to lowering throughput rates or operating hours shall not 

be considered in determining Control Efficiency.

CONTROL EQUIPMENT: air pollution Control Equipment that eliminates, reduces or 

controls the issuance of air emissions.

CONVEYORIZED DEGREASER: any continuously loaded, conveyorized Organic 

Solvent Degreaser, either boiling or non-boiling.

COOLING TOWERS: open water re-circulating devices that use fans or natural draft to 

draw or force air through the device to cool water by evaporation and direct contact. 

This includes, but is not limited to, evaporative condensers, quench or cooling towers 

used for heating ventilation air conditioning (HVAC) and/or industrial cooling processes. 

CREMATORIES AND PATHOLOGICAL INCINERATORS: for the purposes of Rule 

302, Schedule 10, Crematories and Pathological Incinerators are any Furnace or similar 
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enclosed fire chamber burning human or animal tissue or cremating human or animal 

remains.

CUTBACK ASPHALT: paving grade Asphalts liquefied with petroleum distillate and as 

further defined by American Society for Testing and Materials (ASTM) specifications as 

follows:

Rapid Cure Type: ASTM D2028-76

Medium Cure Type: ASTM D2027-76

DAILY EMISSIONS LIMIT: one or a combination of permit conditions, specific to an 

Emissions Unit, which restricts its maximum daily emissions, in pounds per day, at or 

below the emissions associated with the maximum design capacity. A daily emissions 

limitation must be:

1. contained in and Enforceable by the latest Authority to Construct or the latest 

Permit to Operate for the Emissions Unit, and

2. Enforceable on a daily basis, and

3. established pursuant to a permitting action occurring after September 7, 1993.

DAIRY: a Confined Animal Facility (CAF) with operations centered around the 

production of milk, butter, or cheese for commercial purposes.

DECONTAMINATION: for purposes of Rule 412, removal of ROC from contaminated 

soil by aeration, or District approved treatment process.

DEGREASER: tank, tray, drum, or other container in which objects to be cleaned are 

exposed to a liquid or vapor degreasing Organic Solvent

DISTRICT: the Imperial County Air Pollution Control District (ICAPCD).

DRIVEWAY SEALER: a Coating labeled and formulated for application to worn Asphalt 

driveway surfaces to perform one or more of the following functions:

1. fill cracks; or

2. seal the surface to provide protection; or

3. restore or preserve the appearance.

DRY FOG COATING: a Coating labeled and formulated only for spray application such 

that overspray droplets dry before subsequent contact with incidental surfaces in the 

vicinity of the surface Coating activity.
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DUST: minute solid particles released into the air by natural forces or by mechanical 

processes such as crushing, grinding, milling, drilling, and demolishing.

ELECTROSTATIC APPLICATION: a sufficient charging of atomized paint droplets to 

cause deposition, principally by electrostatic attraction.

ELECTROSTATIC DISCHARGE COATING: electrically conductive Coating which 

prevents the build-up of static charge on the surface of an Aerospace Component. 

Applications include, but are not limited to, composites, space vehicles, missiles, and 

helicopter blades.

ELECTROSTATIC SPRAY APPLICATION: any method of spray application of Coatings 

where an electrostatic attraction is created between the part to be coated and the paint 

particles.

EMERGENCY STANDBY TANK: a standby tank used in an emergency to store organic 

liquids during the draining of the primary tank or for use when the operator is granted 

breakdown relief.

EMISSION CONTROL SYSTEM: for the purpose of Rule 427, means any combination 

of capture systems and Control Devices used to reduce VOC emissions from an

Automotive Refinishing Operation.

EMISSION REDUCTION CREDITS (ERCs): reductions of Actual Emissions from an 

Emissions Unit that are registered with the District in accordance with the requirements 

of Rule 214.

EMISSIONS INCREASE: for the purpose of Rule 207, means any increase in a

Stationary Source or an Emissions Unit’s Potential to Emit, calculated pursuant to Rule 

207 Section E.3.

EMISSIONS UNIT: an identifiable operation or piece of process Equipment, such as an 

article, machine, or other contrivance, which emits, has the Potential to Emit, or results 

in the emissions of any air pollutant directly or as Fugitive Emissions.

EMULSIFIED ASPHALT: any Asphalt liquefied with water containing an emulsifier, 

either anionic or cationic.

ENCLOSED GUN CLEANER: a device that is used for the cleaning of spray guns that 

is not open to the ambient air when in use and has a mechanism to force the cleanup 

material through the gun while the cleaner is in operation.

ENFORCEABLE: means certain actions which are assured by verifiable and legally 

binding conditions in an Authority to Construct and/or Permit to Operate.

EQUIPMENT: includes any article, machine, or contrivance that emits, has the Potential 
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to Emit, or reduces emissions of any air pollutant emitted directly or as Fugitive 

Emissions.

ERC: see Emission Reduction Credits

ERC CERTIFICATE: a document identifying the quantity and type of ERCs issued by 

the District to the individual(s) or Source(s) identified on the certificate.

ESSENTIAL PUBLIC SERVICES: the following Sources shall be considered Essential 

Public Services:

1. sewage treatment operations which are publicly owned and operated consistent 

with the approved General Plan; or

2. prison, jail, correctional facility; or

3. police or fire fighting facility; or

4. school or hospital; or

5. landfill gas control or processing system which is publicly owned and operated; or

6. water delivery operations which are publicly owned and operated consistent with 

the approved General Plan; or

7. cleanup operations to remove contaminants from soil or water, mandated by the

Regional Water Quality Control Board, California Department of Health Services, 

Environmental Protection Agency or any other State or Federal law. 

EXCAVATION: for purposes of Rule 412, removal of contaminated soil for the purpose 

of decontamination. Excavated soil may have become contaminated by leaking 

underground or above ground tank, loading rack, spillage, pipeline leak, accidental spill, 

or any other Source.

EXEMPT COMPOUND: a compound identified as exempt under the definition of 

Volatile Organic Compound (VOC). Exempt compound content of a Coating shall be 

determined by US EPA Method 24 or South Coast Air Quality Management District 

(SCAQMD) Method 303-91 (Revised 1993), incorporated by reference in Rule 424,

subsection G.5.j .

EXTREME PERFORMANCE COATING: Coating that encounters acute or chronic 

exposure to salt water, corrosives, caustics, acids, oxidizing agents, wind- or oceandriven debris, or electromagnetic pulses.

FAUX FINISHING COATING: a Coating labeled and formulated to meet one or more of 

the following criteria:
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1. a glaze or textured Coating used to create artistic effects, including, but not 

limited to: dirt, suede, old age, smoke damage, and simulated marble and wood 

grain; or

2. a decorative Coating used to create a metallic, iridescent, or pearlescent 

appearance that contains at least 48 grams of pearlescent mica pigment or other 

iridescent pigment per liter of Coating as applied (at least 0.4 pounds per gallon); 

or

3. a decorative Coating used to create a metallic appearance that contains less 

than 48 grams of elemental metallic pigment per liter of Coating as applied (less 

than 0.4 pounds per gallon), when tested in accordance with South Coast Air 

Quality Management District (SCAQMD) method 318-95, incorporated by 

reference in Rule 424, subsection G.5.d; or

4. a decorative Coating used to create a metallic appearance that contains greater 

than 48 grams of elemental metallic pigment per liter of Coating as applied 

(greater than 0.4 pounds per gallon) and which requires a clear topcoat to 

prevent the degradation of the finish under normal use conditions. The metallic 

pigment content shall be determined in accordance with SCAQMD method 318-

95, incorporated by reference in Rule 424, subsection G.5.d; or

5. a clear topcoat to seal and protect a Faux Finishing Coating that meets the 

requirements of subsections 1 thru 4 of this definition. These clear topcoats must 

be sold and used solely as part of a Faux Finishing Coating system, and must be 

labeled in accordance with Rule 424, subsection E.4.

FEDERAL CLEAN AIR ACT: the Federal Clean Air Act (CAA) as amended in 1990 (42 

United States Code. section 7401 et seq.) and its implementing regulations.

FEDERAL LAN MANAGER: the Secretary of the Department with authority over the 

specified federal lands.

FINISH: the Coating of incomplete vehicles, their parts and components, or Mobile 

Equipment for which the original Coating was not applied from an original Equipment 

manufacturer (OEM) plant Coating assembly line.

FIRE RESISTIVE COATING: a Coating labeled and formulated to protect structural 

integrity by increasing the fire endurance of interior or exterior steel and other structural 

materials. The fire resistive category includes sprayed fire resistive materials and 

intumescent Fire Resistive Coatings that are used to bring structural materials into 

compliance with federal, state, and local building code requirements. Fire Resistive 

Coatings shall be tested in accordance with ASTM E119-07, incorporated by reference 

in Rule 424, subsection G.5.b. Fire Resistive Coatings and testing agencies must be 

approved by building code officials.
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FIRE RETARDANT COATING: a Coating labeled and formulated to retard ignition and 

flame spread, that has been fire tested and rated by a testing agency approved by 

building code officials for use in bringing building and construction materials into 

compliance with federal, state and local building code requirements. The Fire Retardant 

Coating and the testing agency must be approved by building code officials. The Fire 

Retardant Coating shall be tested in accordance with ASTM E84-07, incorporated by 

reference in Rule 424, subsection G.5.a.

Effective January 1, 2011, the Fire Retardant Coating category is eliminated and 

Coatings with fire retardant properties will be subject to the VOC limit of their primary 

category (e.g., Flat, Nonflat, etc.).

FIXED COVER: any cover made out of metal(s), polymer(s) or other material, and 

installed in a permanent position over the liquid.

FLAT COATING: a Coating that is not defined under any other definition in this rule and 

that registers gloss less than 15 on an 85-degree meter or less than 5 on a 60-degree 

meter according to ASTM D 523-89 (1999), incorporated by reference in Rule 424, 

subsection G.5.c .

FLEET VEHICLE: one of a group of ten (10) or more Motor Vehicles under common 

ownership or control and dispatched from a location within Imperial County.

FLIGHT TEST COATINGS: a temporary Coating applied to test aircraft to protect from 

corrosion and to provide required markings during flight test evaluation.

FLOATING COVER: any cover made out of metal(s), polymer(s) or other material, 

which is in contact with a liquid surface at all times.

FLOOR COATING: an opaque Coating that is labeled and formulated for application to 

flooring, including, but not limited to, decks, porches steps, garage floors, and other 

horizontal surfaces which may be subject to foot traffic.

FLOW COATING: a Coating labeled and formulated exclusively for use by electric 

power companies or their subcontractors to maintain the protective Coating systems 

present on utility transformer units. Effective January 1, 2011, a Coating meeting this 

definition will be subject to the applicable category in Table 424-2, except as provided in 

subsection D.2, Most Restrictive VOC Limits found in Rule 424.

FLUORIDES: elemental fluorine and all fluoride compounds.

FORM RELEASE COMPOUND: a Coating labeled and formulated for application to a 

concrete form to prevent the freshly poured concrete from bonding to the form. The 

form may consist of wood, metal, or some material other than concrete.
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FREEBOARD HEIGHT:

1. for a Cold Cleaning Degreaser, distance from the top of the Organic Solvent, or the

Organic Solvent drain to the top of the Degreaser, based on the inside tank 

dimensions.

2. for a Remote Reservoir Degreaser, the distance from the Organic Solvent drain to 

the top of the Degreaser, based on the inside dimensions.

3. for a vapor Degreaser, the distance from the Organic Solvent air-vapor interface to

the top of the basic Degreaser tank, based on the inside tank dimensions.

FREEBOARD RATIO: freeboard height divided by the smaller of the length or width of

the Degreaser.

FROST PROTECTION: the protection of agricultural crops against damage from frost or 

cold weather.

FUEL BURNING EQUIPMENT: the minimum number of boilers, furnaces, jet engines or 

other Fuel Burning Equipment, the simultaneous operations of which are required for 

the production of useful heat or power. Equipment which burns fuel and serves 

primarily as air pollution control Equipment by using a combustion process to destroy air 

contaminants shall not be considered "Fuel Burning Equipment."

FUEL CHANGE: means the transitory operating period when a switch occurs between 

liquid or gaseous fuels, or any combination thereof.

FUEL TANK COATING: a Coating applied to the interior of a fuel tank of an aircraft or 

space vehicle to protect it from corrosion.

FUGITIVE EMISSIONS: those emissions which cannot reasonably pass through a 

stack, chimney, vent, or other functionally equivalent opening.

FUMES: small particles resulting from chemical reaction or from the condensation of 

vapors produced in combustion, distillation or sublimation, or other above ambient 

temperature process.

FURNACE: means any enclosed structure in which heat is produced by the combustion 

of any fuel. 

GASEOUS FUEL: means natural gas, digester gas, landfill gas, methane, ethane, 

propane, butane, or any gas stored as a liquid at high pressure such as liquefied 

petroleum gas.

GASOLINE: any petroleum distillate having a Reid Vapor pressure of 4.0 pounds or 

greater.
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GASOLINE BULK PLANT: an intermediate gasoline loading facility where delivery to 

the facility's storage containers and delivery from the facility is by truck.

GASOLINE DELIVERY VESSEL: a truck, trailer, or railroad car with a storage device 

containing Gasoline, or Gasoline Vapors, used to transport fuel or other petroleum 

products.

GASOLINE TERMINAL: a gasoline loading facility where delivery to the facility's storage 

containers is by means other than truck.

GASOLINE THROUGHPUT: for the purposes of Rule 415, means the volume of 

gasoline dispensed at a gasoline dispensing facility.

GASOLINE VAPORS: the Reactive Organic Compounds in the displaced vapors, 

including any entrained liquid gasoline.

GRAPHIC ARTS COATING OR SIGN PAINT: a Coating labeled and formulated for 

hand-application by artists using brush, airbrush, or roller techniques to indoor and 

outdoor signs (excluding structural components) and murals including lettering enamels, 

poster colors, copy blockers, and bulletin enamels.

GRAPHIC ARTS OPERATION: the application of logos, letters, numbers, or graphic to 

a painted surface by brush, roller, or airbrush.

GRAPHIC DESIGN APPLICATION: the application of logos, letters, numbers, and 

graphics to a painted surface, with or without the use of a template.

GRAZING LAND: open range or fenced fields where animals feed on crops or grasses 

which grow naturally or are planted.

GROUP I VEHICLES: public transit buses and mobile Equipment.

GROUP II VEHICLES: passenger cars, large/heavy duty truck cabs and chassis, light 

and medium duty trucks and vans, and motorcycles.

HALOGENATED HYDROCARBONS: all Halogenated Hydrocarbons listed as exempt 

under the definition of Volatile Organic Compounds.

HAND APPLICATION METHODS: the application of Coatings by nonmechanical handheld Equipment including but not limited to paint brushes, hand rollers, caulking guns, 

trowels, spatulas, syringe daubers, rags, and sponges.

HEALTH AND SAFETY CODE (H&SC): "Health and Safety Code" refers to the 

California Health and Safety Code.
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HEARING BOARD: the Hearing Board of the Air Pollution Control District of Imperial 

County.

HEAT INPUT: means the heat derived from the combustion of a fuel in a unit, calculated 

using the higher heating value, excluding the heat input from preheated combustion air, 

re-circulated flue gases, or exhaust gases from other Sources, including but not limited 

to, Stationary Gas Turbines, Internal Combustion Engines and Kilns.

HEAT INPUT RATING: means the maximum steady state heat input capacity of a unit, 

in BTU per hour, as specified by the manufacturer, or as limited by an Authority to 

Construct or a Permit to Operate.

HEAVY DUTY ENGINE: an engine which is used to propel a Heavy Duty Vehicle.

HEAVY DUTY VEHICLE: any Motor Vehicle having a manufacturer's gross vehicle 

weight rating greater than 6,000 pounds, except passenger cars (Title 13, California 

Code of Regulations, Section 1900 [13 CCR. 1900].)

HEXAVALENT CHROMIUM-CONTAINING WATER TREATMENT CHEMICALS: water 

treatment Additives which contain Hexavalent Chromium (Chrome VI), alone or in 

combination with other water treatment chemicals.

HIGH TEMPERATURE COATING: a high performance Coating labeled and formulated 

for application to substrates exposed continuously or intermittently to temperatures 

above 240°C (400° F).

HIGH TEMPERATURE RESISTANT, THERMAL FLASH RESISTANT, RAIN EROSION 

RESISTANT COATING: for the purposes of Rule 425, means a fluoroelastomeric 

Coating that is designed specifically to protect aerospace vehicles from thermonuclear 

flash, erosion from airborne particles such as rain, ice, sand, etc., and temperatures 

above 450 degrees Fahrenheit resulting from aerodynamic heating.

HIGH VOLATILITY SOLVENT: any Organic Solvent that is not a low volatility Solvent.

HIGH-VOLUME, LOW-PRESSURE (HVLP): spray Equipment permanently labeled as 

such and which is designed and operated between 0.1 and 10 pounds per square inch, 

gauge, (psig) air atomizing pressure measured dynamically at the center of the air cap 

and at the air horns. 

HIGHER HEATING VALUE: means the total heat liberated, including the heat of 

condensation of water, per mass of fuel burned (BTU per pound) when fuel and dry air 

at standard conditions undergo complete combustion and all resultant products are 

brought to standard conditions.

HISTORIC ACTUAL EMISSIONS: Actual Emissions from an existing Emissions Unit 

averaged over a 24 month period immediately preceding the date of application. The
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APCO may approve another 24 month period within the last 60 months, if the APCO 

determines that the other period is more representative of normal operations. Where an 

Emissions Unit has been in operation for less than 24 months a shorter averaging 

period of at least 12 months may be used providing it represents the full operational 

history of the Emission Unit. The Historic Actual Emissions from Emission Units which 

have been in operation for less than 12 months shall be equal to zero. Historic Actual 

Emissions are to be calculated in pounds per quarter for each calendar quarter. Historic 

Actual Emissions in quarters 2 or 3 may be lowered by transferring these emissions to 

quarters 1 or 4, provided that the resulting emissions in quarters 1 or 4 are no higher 

than the higher of quarters 2 or 3.

HISTORIC EMISSIONS: the Potential to Emit of an existing Emissions Unit prior to 

Modification. For a new Emissions Unit Historic Emissions are equal to zero.

HYDROCARBON VAPORS: the Reactive Organic Compounds in the vapors, including 

any entrained organic liquid.

IDENTICAL REPLACEMENT UNIT: a replacement Emissions Unit which is the same as 

the original unit in all respects except for the serial number.

IMPERVIOUS BARRIER: for purposes of Rule 412, physical covering for contaminated 

soil which controls ROC emissions to the extent a ROC analyzer detects less than 

50ppm by volume ROC (measured as hexane) at a distance of three inches above the 

surface.

IMPLEMENTS OF HUSBANDRY: is a vehicle which is used exclusively in the conduct 

of agricultural operations. An Implement of Husbandry does not include a vehicle if its 

existing design is primarily for the transportation of persons or property in a highway.

INCINERATOR: any Furnace or similar enclosed fire chamber, with or without a draft 

control, used for burning refuse or other waste material and where the products of 

combustion are channeled through a flue.

INDUSTRIAL MAINTENANCE COATING: a high performance Architectural Coating, 

including Primers, Sealers, Undercoaters, intermediate coats, and topcoats formulated 

for application to substrates, including floors, exposed to one or more of the following 

extreme environmental conditions listed below and labeled as specified in Rule 424, 

subsection E.5 .

1. immersion in water, wastewater or chemical solutions (aqueous and non-aqueous 

solutions), or chronic exposure of interior surfaces to moisture condensation; or

2. acute or chronic exposure to corrosive, caustic or acidic agents, or to chemicals, 

chemical fumes, chemical mixtures or solutions; or

3. frequent exposure to temperatures in excess of 250°F (121°C); or
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4. frequent heavy abrasion, including mechanical wear and frequent scrubbing with 

industrial Solvents, cleansers or scouring agents; or

5. exterior exposure of metal structures and structural components.

INTERNAL COMBUSTION ENGINE: any spark or compression ignited reciprocating 

Internal Combustion Engine that is attached to a foundation at a location, or is portable 

and operated at a location for more than 90 days in any consecutive twelve month 

period, excluding engines used for self propulsion of a vehicle.

KILN: means an oven, Furnace, or heated enclosure used for processing a substance 

by burning, firing, or drying.

LACQUER: a clear or opaque wood Coating, including clear lacquer Sanding Sealers, 

formulated with cellulosic or synthetic resins to dry by evaporation without chemical 

reaction and to provide a solid, protective film. Effective January 1, 2011, a Coating

meeting this definition will be subject to the applicable category in Table 424-2, except 

as provided in subsection D.2, Most Restrictive VOC Limits found in Rule 424.

LARGE CONFINED ANIMAL FACILITY (LCAF): any Confined Animal Facility that 

maintains on any one day: 500 or more milk-producing dairy cows; or 3,500 or more 

beef cattle, calves, heifers, or other cattle; or 100,000 or more turkeys; or 400,000 or 

more chickens other than laying hens; or 400,000 or more laying hens; or 3,000 or more 

swine; or 15,000 or more sheep, lambs, or goats; or 2,500 or more horses; or 400,000 

or more ducks; or 30,000 or more rabbits or other animals.

LARGE/HEAVY DUTY TRUCKS: any truck having a manufacturer's gross vehicle 

weight rating of over 10,000 pounds.

LEAK OF REACTIVE ORGANIC COMPOUNDS: an emission of a liquid containing 

Reactive Organic Compounds at a rate of more than 3 drops per minute, as a 

continuous stream, or as a visible mist; or an emission of a gas containing Reactive 

Organic Compounds which causes an appropriate analyzer sampling 1 centimeter from 

a Source to register at least 10,000ppm as methane as determined by US EPA 

Reference Method 21.

LEAK-FREE: for the purposes of Rule 415, means a liquid leak of no more than three 

drops per minute excluding losses which occur upon disconnecting transfer fittings. 

Provided such disconnect losses do not exceed 10 milliliters (0.34 fluid ounces) per 

disconnect, averaged over three disconnects.

LEAN-BURN ENGINE: any spark or compression ignited Internal Combustion Engine 

that is operated with an exhaust gas stream oxygen concentration of four percent (4%) 

by volume, or greater. The exhaust gas oxygen content shall be determined from the 

uncontrolled exhaust gas stream.
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LIGHT DUTY TRUCK: any Motor Vehicle, rated at 6,000 pounds gross vehicle weight or 

less, which is designed primarily for purposes of transportation of property or is a 

derivative of such a vehicle, or is available with special features enabling off-street or 

off-highway operation and use (13 CCR 1900.)

LIQUID FUEL: means any fuel which is a liquid at standard conditions including but not 

limited to distillate oils, kerosene and jet fuel. Liquefied gaseous fuels are not liquid 

fuels.

LOADING FACILITY: any aggregation or combination of gasoline loading Equipment 

which is both (1) possessed by one person, and (2) located so that all the gasoline 

loading outlets for such aggregation or combination of loading Equipment can be 

encompassed within any circle of 300 feet in diameter.

LOW EMISSION VEHICLE: any vehicle certified by the California Air Resources Board 

(CARB) to the transitional, low, ultra low, or zero emission vehicle standards established 

in 13 CCR 1960.1

LOW SOLIDS COATING: a Coating containing 0.12 kilogram or less of solids per liter (1 

pound or less of solids per gallon) of Coating material as recommended for application 

by the manufacturer. The VOC content for Low Solids Coatings shall be calculated in 

accordance with the definition of VOC Actual.

LOW VOLATILITY SOLVENT: any Organic Solvent, including emulsions containing no 

more than 2% Reactive Organic Compounds (ROC) by weight as determined by US 

EPA test method 24.

LOWEST ACHIEVABLE EMISSION RATE (LAER): for any Stationary Source or 

Modification the more stringent of:

1. the most stringent emissions limitation which is contained in the implementation 

plan of any state for such class or category of Stationary Source, unless the Owner 

or Operator of the proposed Stationary Source demonstrates that such limitations 

are not achievable; or

2. the most effective emissions control technique which has been achieved in 

practice, for such class or category of Source as determined by the APCO; or

3. the emission limitation specified for such class or category of Source under 

applicable federal New Source Performance Standards pursuant to Section 111 of 

the Clean Air Act; or

4. any other emissions control technique found after public hearing, by the APCO or 

the California Air Resources Board to be technologically feasible and cost effective 

for such class or category of Sources or for a specific Source.
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MAGNESITE CEMENT COATING: a Coating labeled and formulated for application to 

Magnesite Cement decking to protect the Magnesite Cement substrate from erosion by 

water.

MAJOR MODIFICATION: a Modification to a Major Stationary Source which results in a 

Significant Emissions Increase and a Significant Net Emissions Increase of the pollutant 

for which the Stationary Source is classified as a Major Stationary Source.

MAJOR PROJECT: for the purpose of Rule 206 and 301 means a Project which will 

emit pollutants under any of the following conditions: 250 or more lbs/day controlled for 

any single pollutant; 100 or more tons/yr uncontrolled for any single pollutant; 250 or 

more tons/yr uncontrolled for all emissions combined.

MAJOR STATIONARY SOURCE: means a Stationary Source which emits, or has the 

Potential to Emit 100 tons per year (tpy) or more of Volatile Organic Compounds or 

Oxides of Nitrogen, or 70 tpy or more of PM10, or a PM10 Precursor or 100 tpy or more 

of PM2.5 or a PM2.5 Precursor. In addition, any physical change occurring at a 

Stationary Source which is not already a Major Stationary Source, and which 

Modification would constitute a Major Stationary Source by itself, makes the Source a 

Major Stationary Source.

MAKE-UP SOLVENT: Organic Solvent added to a Degreaser to replace Organic 

Solvent lost through evaporation, carry-out, splashing, leakage, or disposal.

MANUFACTURER’S MAXIMUM THINNING RECOMMENDATION: the maximum 

recommendation for thinning that is indicated on the label or lid of the Coating container.

MANURE: the accumulated animal excrement in or around a livestock feed yard that 

does not undergo decomposition as would occur on open grazing land or natural 

habitat. This definition includes feces or urine which may be mixed with bedding 

materials, with spilled feed or with soil. 

MASKANT: a Coating applied directly to a metal part or other surface to protect surface 

areas during chemical milling, anodizing, aging, bonding, plating, etching, or other 

chemical surface operations.

MASTIC TEXTURE COATING: a Coating labeled and formulated to cover holes and 

minor cracks and to conceal surface irregularities, and is applied in a single coat of at 

least 10 mils (0.010 inch) dry film thickness.

MEDIUM DENSITY FIBERBOARD (MDF): a composite wood product, panel, molding, 

or other building material composed of cellulosic fibers (usually wood) made by dry 

forming and pressing of a resinated fiber mat.

MEDIUM DUTY VEHICLE: any pre-1995 model year Heavy-Duty Vehicle having a 
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manufacturer's gross vehicle weight rating of 8,500 pounds or less; any 1992 through 

2006 model-year heavy-duty low-emission, ultra-low-emission, super-ultra-low-emission 

or zero-emission vehicle certified to the standards in section 1960.1(h)(2) of the 

California Code of Regulations (CCR) having a manufacturer's gross vehicle weight 

rating of 14,000 pounds or less; any 1995 through 2003 model-year heavy-duty vehicle

certified to the standards in section 1960.1(h)(1) of the CCR having a manufacturer'=s 

gross vehicle weight rating of 14,000 pounds or less; and any 2000 and subsequent 

model heavy-duty low-emission, ultra-low-emission, super-ultra-low-emission or zeroemission vehicle certified to the standards in Section 1961(a)(1), 1962, or 1962.1 having 

a manufacturer’s gross vehicle weight rating between 8,501 and 14,000 pounds.

(California Code of Regulations Title 13, Division 3, Chapter 1, Article 1, §1900) 

METALLIC/IRIDESCENT COLOR COATING: any Coating that contains more than 

0.042 pounds per gallon (5 grams per liter) of metal or iridescent particles as applied, 

where such particles are visible in the dried film.

METALLIC PIGMENTED COATING: a Coating that is labeled and formulated to provide 

a metallic appearance. Metallic Pigmented Coatings must contain at least 48 grams of 

elemental metallic pigment (excluding zinc) per liter of Coating as applied (at least 0.4 

pounds per gallon), when tested in accordance with SCAQMD Method 318-95, 

incorporated by reference in Rule 424, subsection G.5.d. The Metallic Pigmented 

Coating category does not include Coatings applied to roofs or Zinc-Rich Primers.

MILITARY BASE: means a Military Base that is designated for closure or downward 

realignment pursuant to the Defense Base Closure and Realignment Act of 1988 (P.L. 

100-526) or the Defense Base Closure and Realignment Act of 1990 (10 United States 

Code Sec. 2687 et seq.).

MINOR PROJECT: for the purpose of Rules 206 and 301, a Project for which 

uncontrolled emissions will not exceed 35 lbs/day of any pollutant, and for which there 

will be no emission of pollutants which are toxic Air Contaminants or for which the 

District has been designated nonattainment.

MOBILE EQUIPMENT: for the purposes of Rule 427 is any device that may be drawn 

and/or driven on rails or a roadway including, but not limited to, trains, railcars, truck 

trailers, mobile cranes, bulldozers, street cleaners, and Implements of Husbandry for 

agriculture.

MOBILE SOURCE EMISSION REDUCTION CREDIT (MSERC): Actual Emission 

Reductions which have been recognized by the District as being banked and registered 

with a MSERC certificate issued in accordance with the requirements of Rule 214.1.

MOBILE TRANSPORT TANK: any tank truck or trailer, railroad tank car, or tanker used 

to transport reactive organic liquids.

MODELING: use of an air quality simulation model, based on specified assumptions 
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and data, which has been approved in writing by the executive officer of the California 

Air Resources Board.

MODIFICATION: any physical change, change in method of operation of, or addition to, 

an existing Emissions Unit, or any change in hours of operation or production rate which 

would necessitate a change in permit conditions. 

Unless previously limited by a permit condition, the following shall not be considered a 

Modification:

1. change in ownership of an existing Stationary Source with valid Permit(s) to 

Operate.

2. routine maintenance or repair.

3. an Identical Replacement Unit, if the Modification does not result in a Major 

Modification.

A Modification of an Emissions Unit also occurs when there is an increase in emissions 

from such a unit caused by a Modification of the Stationary Source and the Emissions 

Unit is not subject to a Daily Emissions Limit. 

A Modification to a Stationary Source shall include any Modification of its permitted 

Emissions Unit(s) or the addition of any new Emissions Unit(s).

A Reconstructed Stationary Source shall be treated as a new Stationary Source and not 

as a Modification.

MOTOR VEHICLE: any self-propelled vehicle, but not limited to, cars, trucks, buses, 

golf carts, vans, motorcycles, tanks, and armored personnel carriers.

MOBILE SOURCE EMISSION REDUCTION CREDIT (MSERC) PROGRAM: as 

recognized by the California Air Resources Board, any activity undertaken by a Person 

which produces actual Mobile Source Emission Reductions within Imperial County for 

purposes of establishing ERC’s pursuant to Rules 214 and 214.1. A program can be a 

onetime action, a series of one time actions or a continuous set of actions.

MOBILE SOURCE EMISSION REDUCTION CREDIT (MSERC) REGISTRY: a tracking 

maintained by the District which records all MSERC deposits, withdrawals, transfers 

and transactions as required by Rule 214.1.

MULTI-COLOR COATING: a Coating that is packaged in a single container and that is 

labeled and formulated to exhibit more than one color when applied in a single coat. For 

purposes of Rule 427, means any Coating that exhibits more than one color in the dried 

film after a single application, is packaged in a single container, and hides surface 

defects on areas of heavy use, and which is applied over a Primer or Adhesion 
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Promoter.

MULTIPLE-CHAMBER INCINERATOR: any article, machine, Equipment, contrivance, 

structure or any part of a structure used to dispose of combustible refuse by burning, 

consisting of three or more refractory walls, interconnected by gas passage ports or 

ducts, and employing adequate design parameters necessary for maximum combustion 

of the material to be burned.

NO-BURN DAY: any day on which Agricultural Burning is prohibited by the California Air 

Resources Board or by the District.

NO-BURN LIST: a list of fields for which ERC's have been applied and on which burning 

will not be allowed.

NONATTAINMENT AREA: an area designated by a state or federal agency as 

exceeding a state or National Ambient Air Quality Standard.

NONATTAINMENT POLLUTANT: any pollutant or Precursor which has been 

designated "nonattainment" by the US EPA as codified in 40 CFR Section 81.305, or 

that has been designated "nonattainment" by the CARB pursuant to H&SC Section 

39607.

NONFLAT COATING: a Coating that is not defined under any other definition in this 

Rule and that registers a gloss of 15 or greater on an 85-degree meter and 5 or greater 

on a 60-degree meter according to ASTM D523-89 (1999), incorporated by reference in 

Rule 424, subsection G.5.c .

NONFLAT-HIGH GLOSS COATING: a Nonflat Coating that registers a gloss of 70 or 

greater on a 60-degree meter according to ASTM D523-89 (1999), incorporated by 

reference in Rule 424, subsection G.5.c. Nonflat–High Gloss Coatings must be labeled 

in accordance with Rule 424, subsection E.12.

NON-PERMITTED EMISSIONS: for the purpose of Rule 214, Non-Permitted Emissions 

are emissions which are not governed under a District permit.

OFFSET: the use of an emission decrease to compensate for an Emission Increase 

from a new or modified Stationary Source subject to the requirements of Rule 207.

OFFSET FILL LINE: any liquid fill line which contains one or more pipe bends, and the 

horizontal distance between the truck delivery connection and the storage container fill 

opening is 6.1 meters (20 feet) or greater.

OIL-EFFLUENT WATER SEPARATOR: any device or piece of Equipment used to 

remove petroleum compounds or associated chemicals from effluent water

OPACITY: the degree to which emissions reduce the transmission of light and obscure 
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the view of the background.

OPAQUE STAINS: all Stains that are not classified as Semi-Transparent Stains.

OPAQUE WOOD PRESERVATIVES: all Wood Preservatives not classified as clear or 

Semi-Transparent Wood Preservatives or as below ground Wood Preservatives.

OPEN BURNING IN AGRICULTURAL OPERATIONS IN THE GROWING OF CROPS 

OR RAISING OF FOWLS OR ANIMALS:

1. the burning in the open of materials produced wholly from operations in the 

growing and harvesting of crops or raising of fowls or animals for the primary 

purpose of making a profit, providing a livelihood, or of conducting agricultural 

research or instruction by an educational institution; and

2. the burning of grass and weeds in or adjacent to fields in cultivation or being 

prepared for cultivation in connection with operations qualifying under 1 above; and

3. the burning of materials not produced wholly from such operations, but which are 

intimately related to the growing or harvesting of crops and which are used in the 

fields, except as prohibited by District regulations. Examples are trays for drying 

raisins, date palm protection paper, and fertilizer and pesticide sacks or 

combustible containers, where the sacks or combustible containers are emptied in 

the field, or other reasonable nearby location under the direct control of the farm 

operator. This does not include products made from rubber. 

OPEN OUTDOOR FIRE: the complete or partial burning or smoldering of any 

combustible refuse or other material of any type, directly exposed to the Atmosphere, 

whether or not enclosed in a fireproof container, where the products of combustion are 

not channeled through a flue.

OPEN-TOP VAPOR DEGREASER: any batch loaded, boiling Organic Solvent 

Degreaser.

ORCHARD OR CITRUS GROVE HEATER: any article, machine, Equipment, or other 

contrivance, burning any type of fuel, capable of emitting Air Contaminants, used or 

capable of being used for the purpose of giving protection from frost damage. 

Contrivances commonly known as wind machines are not included.

ORGANIC CONTENT: for purposes of Rule 412, degree of contamination used to limit 

daily rate contaminated soil may be added to an active soil aeration pile.

ORGANIC MATERIALS: chemical compounds of carbon excluding carbon monoxide, 

carbon dioxide, carbonic acid, metallic carbonates and ammonium carbonate. 

ORGANIC SOLVENTS: includes diluents and thinners and are defined as organic 
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materials which are liquids at standard conditions and which are used as dissolvers, 

viscosity reducers, or cleaning agents.

OTHER CATTLE FACILITY: a Confined Animal Facility (CAF) housing cattle which 

does not meet the definition of a Beef Feedlot or Dairy.

OWNER OR OPERATOR: includes, but is not limited to, any Person who owns, leases, 

supervises or operates Equipment.

PARCEL: a legally subdivided piece of land or combined lands under common 

ownership.

PARTICLEBOARD: a composite wood product panel, molding, or other building 

material composed of cellulosic material (usually wood) in the form of discrete particles, 

as distinguished from fibers, flakes, or strands, which are pressed together with resin.

PARTICULATE MATTER: any material, except uncombined water, which exists in a 

finely divided form as a liquid or solid at standard conditions. Dust shall also be 

considered as Particulate Matter.

PARTICULATE MATTER (PM10): Particulate Matter with an aerodynamic diameter 

equal to or less than 10 micrometers. Gaseous emissions which condense to form 

Particulate Matter at ambient temperatures shall be included.

PARTICULATE MATTER (PM2.5): Particulate Matter with an aerodynamic diameter 

equal to or less than 2.5 micrometers. Gaseous emissions which condense to form 

Particulate Matter at ambient temperatures shall be included.

PASSENGER CAR: “any motor vehicle designed primarily for transportation of persons 

and having a design capacity of twelve persons or less” (California Code of Regulations 

Title 13, Division 3, Chapter 1, Article 1, §1900)

PEARLESCENT: exhibiting various colors depending on the angles of illumination and 

viewing, as observed in mother-of-pearl.

PERMANENT: the actual emission reductions that continue or endure for the duration of 

any Project utilizing the resulting ERC’s as Offsets.

PERMISSIVE-BURN DAY: any day on which Agricultural Burning is not prohibited by 

the California Air Resources Board or the District.

PERMIT TO OPERATE: the written permit issued by the District for the operation of any 

facility, article, machine, Equipment, Emission Unit or other contrivance.

PERSON: any person, firm, association, organization, partnership, business trust, 

corporation, company, limited liability company, contractor, supplier, installer, user or 
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owner, or any federal, state or local government agency, public district, or any officer or 

employee thereof.

PHASE I VAPOR RECOVERY SYSTEM: a system which recovers the hydrocarbon 

vapors resulting from the transfer of r Reactive o Organic c Compounds into a 

Stationary Tank or Mobile Transport Tank.

PHASE II VAPOR RECOVERY SYSTEM: a gasoline vapor recovery system that 

recovers vapors during the fueling of Motor Vehicles from stationary storage tanks.

PHOTOCHEMICALLY REACTIVE SOLVENT: any Solvent with an aggregate of more 

than 20 percent of its total volume composed of the chemical compounds classified 

below or which exceeds any of the following individual percentage composition 

limitations, referred to the total volume of Solvent:

1. a combination of hydrocarbons, alcohols, aldehydes, esters, ethers, or ketones 

having an olefinic or cyclo-olefinic type of unsaturation: 5 percent;

2. a combination of aromatic compounds with eight or more carbon atoms to the 

molecule except ethylbenzene: 8 percent;

3. a combination of ethylbenzene, ketones having branched hydrocarbon structures, 

or toluene: 20 percent.

PLYWOOD: a panel product consisting of layers of wood veneers or composite core 

pressed together with resin. Plywood includes panel products made by either hot or 

cold pressing (with resin) veneers to a platform.

PM2.5 NONATTAINMENT AREA: that portion of Imperial County which lies within the 

line described as follows: (San Bernardino Base and Meridian) Beginning at the 

intersection of the United States-Mexico Border and the southeast corner of T17S 

R11E, then north along the range line of the eastern edge of range R11E, then east 

along the township line of the southern edge of T12S to the northeast corner of T13S 

R15E, then south along the range line common to R15E and R16E, to the United 

States-Mexico border.

POST-CONSUMER COATING: finished Coatings generated by a business or consumer 

that have served their intended end uses, and are recovered from or otherwise diverted 

from the waste stream for the purpose of recycling.

POTENTIAL EMISSIONS: the sum of the maximum emissions from all Emissions Units 

at a Stationary Source, based on the maximum design capacity, unless otherwise 

limited by practically and legally Enforceable conditions contained in the Authority to 

Construct and/or Permit to Operate, expressed in terms of pounds per quarter. (Pounds 

per quarter for PM10, PM2.5 and sulfur oxides shall be determined by multiplying the 

Daily Emission Limit, in pounds per day, by the permitted operating days per quarter.)
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POTENTIAL TO EMIT: the maximum capacity of an Emissions Unit to emit an Affected 

Pollutant based on its physical and operational design. Any physical or operational 

limitation on the capacity of the Emission Unit to emit a pollutant, including air pollution 

Control Equipment and restrictions on hours of operation or on the type or amount of 

material combusted, stored, or processed, shall be treated as part of its design only if 

the limitation or the effect it would have on emissions is incorporated into the applicable 

permit as a practically and legally Enforceable permit condition.

POWER RATING: means the maximum, continuous power output of a Stationary Gas 

Turbine(s), in megawatts (MW) or equivalent, as certified by the manufacturer unless 

limited by a condition in a District Authority to Construct or a Permit to Operate. Power 

augmentation shall not be included in Power Rating.

PRECURSOR: a directly emitted Affected Pollutant that, when released into the 

Atmosphere, forms or causes to be formed or contributes to the formation of a 

secondary pollutant for which a state or National AAQS has been adopted, or whose 

presence in the Atmosphere will contribute to the violation of one or more state or 

National AAQS. The following Precursor secondary pollutant relationships shall be 

used for the purposes of these regulations:

PRECURSORS SECONDARY POLLUTANTS

Hydrocarbons and substituted a) Photochemical Oxidant (Ozone)

hydrocarbons (Volatile b) The organic fraction of PM10.

Organic Compounds.) c) Organic fraction of PM2.5, if Volatile Organic 

Compounds are determined to be a 

necessary part of the PM2.5 control strategy 

in the attainment demonstration approved by 

the US EPA in the SIP.

Nitrogen Oxides (NOx) a) Nitrogen Dioxide (NO2)

b) The nitrate fraction of PM10

c) Photochemical Oxidant (Ozone)

d) The nitrate fraction of PM2.5

Sulfur Oxides (SOx) a) Sulfur Dioxide (SO2)

b) Sulfates (SO4)

c) The sulfate fraction of PM10

d) The sulfate fraction of PM2.5

Ammonia a) Organic fraction of Nitrate, if ammonia is 

determined to be a necessary part of the 

PM2.5 control strategy in the attainment 

demonstration approved by the US EPA in 

the SIP. 
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PREPREG COMPOSITE MATERIAL: for the purposes of Rule 425, means, a 

reinforcing material impregnated with partially polymerized organic resins and ready for 

application.

PRESSURE TANK: a tank which maintains working pressure sufficient at all times to 

prevent hydrocarbon vapor or gas loss into the Atmosphere.

PRE-TREATMENT WASH PRIMER: a Primer that contains a minimum of 0.5 percent 

acid, by weight, when tested in accordance with ASTM D1613-06, incorporated by 

reference in Rule 424, subsection G.5.e that is labeled and formulated for application 

directly to bare metal surfaces to provide corrosion resistance and to promote adhesion 

of subsequent topcoats.

PRETREATMENT COATING: for the purposes of Rule 427, any Coating that contains a 

minimum of one-half (0.5) percent acid by weight and not more than 16 percent solids 

by weight necessary to provide surface etching and is labeled and formulated for 

application directly to bare metal surfaces to provide corrosion resistance and adhesion.

PRIMER, SEALER, AND UNDERCOATER: for purposes of Rule 424, a Primer, Sealer, 

and Undercoater is a Coating labeled and formulated for one or more of the following 

purposes;

1. to provide a firm bond between the substrate and the subsequent Coatings; or

2. to prevent subsequent Coatings from being absorbed by the substrate; or

3. to prevent harm to subsequent Coatings by materials in the substrate; or

4. to provide a smooth surface for the subsequent application of Coatings; or

5. to provide a clear finish coat to seal the substrate; or

6. to block materials from penetrating into or leaching out of a substrate.

PRIMER: for purposes of Rule 427, Primer is any Coating which is labeled and 

formulated for application to a substrate to provide:

1. a bond between the substrate and subsequent coats

2. corrosion resistance

3. a smooth substrate surface, or

4. resistance to penetration of subsequent coats, and on which a subsequent Coating

is applied.
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Primers may be pigmented.

PRIMER SEALER: for purposes of Rule 427, a Primer Sealer is any Coating which is 

labeled and formulated for application prior to the application of a color Coating for the 

purpose of color uniformity, or to promote the ability of the underlying Coating to resist 

penetration by the color Coating.

PRIMER SURFACER: any Coating applied prior to the application of a Topcoat for the 

purpose of corrosion resistance, adhesion of the Topcoat, and which promotes a 

uniform surface by filling in surface imperfections.

PRIORITY RESERVE: a depository of emission reductions for loan to applicable priority 

sources for use as Offsets.

PROCESS HEATER: means any combustion Equipment fired with liquid and/or 

gaseous fuel and which transfers heat from the combustion gases to water or processes 

stream. Heaters used for swimming pools, spas and/or therapy pools shall be 

considered Process Heaters. “Process Heater” shall not include any combustion 

Equipment where the material being heated is in direct contact with the products of 

combustion, such as Furnaces or Kilns, or any unfired waste heat recovery heater that 

is used to recover sensible heat from the exhaust of any combustion Equipment.

PROCESS WEIGHT PER HOUR: the total weight of all materials introduced into any 

specific process which process may cause any discharge into the Atmosphere. Solid 

fuels charged will be considered as part of the process weight, but liquid and gaseous 

fuels and combustion air will not. "The Process Weight Per Hour" will be derived by 

dividing the total process weight by the number of hours in one complete operation from 

the beginning of any given process to the completion thereof, excluding any time during 

which the Equipment is idle. Cooling air and cooling water will not be considered as 

part of the process weight.

PROJECT: activity, for which a permit is required, or that has the Potential to Emit Air 

Contaminants. A project includes all of the Emission Units associated with the scope of 

the preconstruction application for a new or modified Stationary Source and any 

Emissions Unit(s) indirectly affected.

PROPOSED EMISSIONS: the Potential to Emit for a new or post Modification 

Emissions Unit.

QUANTIFIABLE: means a reliable, replicable and accurate basis for calculating the 

amount, rate, nature and characteristic of an emission reduction by adhering to a 

quantification protocol that can be established, considering US EPA, CARB and District 

policies and procedures.

QUARTERLY: the calendar quarter beginning in January 1, April 1, July 1, and October 
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1.

QUICK-DRY ENAMEL: a Nonflat Coating that is labeled as specified in Rule 424, 

subsection E.9 and that is formulated to have the following characteristics:

1. is capable of being applied directly from the container under normal conditions with 

ambient temperatures between 60oF and 80oF (16oC and 27oC).

2. when tested in accordance with ASTM D1640-95, incorporated by reference in 

Rule 424, section G.5.f, sets to touch in 2 hours or less, is tack free in 4 hours or 

less, and dries hard in 8 hours or less by the mechanical test method; and

3. has a dried film gloss of 70 or above on a 60 degree meter.

Effective January 1, 2011, a Coating meeting this definition will be subject to the 

applicable category in Table 424-2, except as provided in subsection D.2, Most 

Restrictive VOC Limits found in Rule 424.

QUICK-DRY PRIMER, SEALER AND UNDERCOAT: a Primer, Sealer or Undercoat 

that is dry to the touch in 30 minutes and can be recoated in 2 hours when tested in 

accordance with ASTM D1640-95, incorporated by reference in Rule 424, section G.5.f. 

Effective January 1, 2011, a Coating meeting this definition will be subject to the 

applicable category in Table 424-2, except as provided in subsection D.2, Most 

Restrictive VOC Limits found in Rule 424.

RAINY PERIOD: for the purpose of Rule 420, when the twenty-four (24) hour measured 

rainfall amount ending at 4 a.m. is between 0.20 inches and 0.75 inches.

RANGE IMPROVEMENT BURNING: the use of open outdoor fires to remove 

vegetation for a wildlife, game or livestock habitat or for the initial establishment of an 

agricultural practice on previously uncultivated land.

RATED BRAKE HORSEPOWER: the maximum Rated Brake Horsepower specified for 

the engine by the manufacturer and listed on the nameplate for the unit, regardless of 

any derating, unless limited by the engine's Permit to Operate (PTO).

REACTIVE ORGANIC COMPOUND (ROC): see Volatile Organic Compound (VOC) 

definition.

REACTIVE PENETRATING SEALER: a clear or pigmented Coating that is labeled and 

formulated for application to above-grade concrete and masonry substrates to provide 

protection from water and waterborne contaminants, including, but not limited to, alkalis, 

acids, and salts. Reactive Penetrating Sealers must penetrate into concrete and 

masonry substrates and chemically react to form covalent bonds with naturally 

occurring minerals in the substrate. Reactive Penetrating Sealers line the pores of 

concrete and masonry substrates with a hydrophobic Coating, but do not form a surface 
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film. Reactive Penetrating Sealers must meet all of the following criteria:

1. the Reactive Penetrating Sealer must improve water repellency at least 80 

percent after application on a concrete or masonry substrate. This performance 

must be verified on standardized test specimens, in accordance with one or more 

of the following standards, incorporated by reference in Rule 424, subsection 

G.5.u, ASTM C67-07, or ASTM C97-02, or ASTM C140-06; and

2. the Reactive Penetrating Sealer must not reduce the water vapor transmission 

rate by more than 2 percent after application on a concrete or masonry substrate. 

This performance must be verified on standardized test specimens in accordance 

with ASTM E96/E96M-05, incorporated by reference in Rule 424, subsection 

G.5.v; and

3. products labeled and formulated for vehicular traffic surface chloride screening 

applications must meet the performance criteria listed in the National 

Cooperative Highway Research Report 244 (1981), incorporated by reference in 

Rule 424, subsection G.5.w.

Reactive Penetrating Sealers must be labeled in accordance with Rule 424, subsection 

E.10.

REAL: a "real" emission reduction means that actual air emissions are reduced and that 

they are actually occurring and not artificially devised.

REASONABLE FURTHER PROGRESS: annual incremental reductions in emissions 

required for the purpose of ensuring attainment of state or federal Ambient Air Quality 

Standards by the applicable date.

REASONABLY AVAILABLE CONTROL TECHNOLOGY (RACT): is the most stringent 

of the following control options:

1. the most effective emission limits in existing regulations that are currently in effect 

in any District whose nonattainment status is designated as moderate, with such 

limits resulting from the application of retrofit technologies judged by the APCO to 

be demonstrated and reliable.

2. emission limits identified in existing Suggested Control Measures (SCM's), model 

rules, the US EPA’s Control Techniques Guidelines (CTG's) or other such 

documents.

3. emission limits in new (post 1988) SCM's and the technical review group of the 

California Air Pollution Control Officers Association approved Reasonably 

Availability Control Technology/Best Available Retrofit Control Technology 

(RACT/BARCT) determinations, which are not identified as BACT and are less 

stringent than BACT.
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4. the lowest emission limit that can be achieved by the specific Source by the 

application of control technology taking into account environmental impacts, 

technological feasibility, cost-effectiveness, and the specific design features or 

extent of necessary Modifications to the Source. Emission limits for existing 

specific Sources may be found in the field studies and evaluations of District 

regulations conducted by the US EPA and the CARB.

5. the lowest emission limit achieved for the Source category that is technically 

feasible, economically reasonable and achieved in practice anywhere (including 

outside the United States), with such limits resulting from the application of retrofit 

control technologies judged by the APCO to be demonstrated and reliable.

6. any combination of control technologies that will achieve emission reductions 

equivalent to that resulting from the most stringent option listed above.

REBUILT EQUIPMENT: for the purposes of Rule 415, means any component of a 

Vapor Recovery System that has undergone repair or replacement of any or all of its 

internal parts. 

RECONSTRUCTED STATIONARY SOURCE: any Stationary Source undergoing 

physical Modification where the fixed capital cost of the new components exceeds 50 

percent of the fixed capital cost of a comparable entirely new Stationary Source. Fixed 

capital cost means that capital needed to provide all the depreciable components.

RECYCLED COATING: an Architectural Coating formulated such that it contains a 

minimum of 50% by volume post-consumer Coating, with a maximum of 50% by volume 

secondary industrial materials or virgin materials.

REDUCER: the Solvent used to thin enamel.

REDUCTION OF ANIMAL MATTER: processing animal matter by any process, 

including rendering, cooking, drying, dehydration, digestion, and evaporation, but not 

including any processing of food for human consumption.

REFINISHING: any Coating of vehicles, their parts and components, or Mobile 

Equipment, including partial body collision repairs, for the purpose of protection or 

beautification and which is subsequent to the original Coating applied at an original 

Equipment manufacturing (OEM) plant Coating assembly line.

REMOTE RESERVOIR: liquid Organic Solvent tank which is completely enclosed 

except for a Solvent return opening no larger than 100 cm2 (15 in2) which allows used 

Organic Solvent to drain into it from a separate Organic Solvent sink or work area and 

which is not accessible for soaking parts.

RESIDENTIAL: areas where people reside or lodge, including, but not limited to, single 
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and multiple family dwellings, condominiums, mobile homes, apartment complexes, 

motels, and hotels.

RESIDENTIAL RUBBISH: refuse originating from Residential uses and includes wood, 

paper, cloth, cardboard, tree trimmings, leaves, lawn clippings, and dry plants, but not 

household garbage.

RETAIL FACILITY OR RETAIL SERVICE STATION: is any Motor Vehicle refueling 

facility subject to payment of California sales tax on gasoline sales.

RICH BURN ENGINE: any spark or compression ignited Internal Combustion Engine 

that is operated with an exhaust gas stream oxygen concentration of less than four 

percent (4%) by volume. The exhaust gas oxygen content shall be determined from the 

uncontrolled exhaust gas stream.

ROAD OILS: slow cure asphalts.

ROC ANALYZER: hydrocarbon analyzer satisfying United States Environmental 

Protection Agency Method 21, 40 CFR Part 60.

ROOF COATING: a non-bituminous Coating labeled and formulated for application to 

roofs for the primary purpose of preventing water penetration, reflecting ultraviolet light, 

or reflecting solar radiation.

RULE: a Rule of the Air Pollution Control District of Imperial County.

RUST PREVENTATIVE COATING: a Coating formulated to prevent the corrosion of 

metal surfaces for one or more of the following applications:

1. direct-to-metal Coating; or

2. Coating intended for application over rusty, previously coated surfaces.

The Rust Preventative category does not include the following:

3. Coatings that are required to be applied as a topcoat over a p Primer; or

4. Coatings that are intended for use on wood or any other non-metallic surface.

Rust Preventative Coatings are for metal substrates only and must be labeled as such, 

in accordance with the labeling requirements in Rule 424, subsection E.7.

SANDING SEALER: a clear or semi-transparent Wood Coating labeled and formulated 

for application to bare wood to seal the wood and to provide a coat that can be abraded 

to create a smooth surface for subsequent applications of Coatings. A Sanding Sealer 

that also meets the definition of a Lacquer is not included in this category, but is 
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included in the Lacquer category. Effective January 1, 2011, a Coating meeting this 

definition will be subject to the applicable category in Table 424-2, except as provided in 

subsection D.2, Most Restrictive VOC Limits found in Rule 424.

SEASONAL SOURCE: any Stationary Source with more than 75 percent of its annual 

operating hours within a consecutive 120 day period.

SECONDARY EMISSIONS: means emissions which would occur as a result of the 

Construction or operation of a Stationary Source or Modification, but do not come from 

the Stationary Source or Modification itself. Secondary emissions must be specific, well 

defined, Quantifiable, and impact the same general area as the Stationary Source or 

Modification which causes the Secondary Emissions. Secondary Emissions include 

emissions from any offsite support facility which would not be constructed or increase its 

emissions except as a result of the Construction or operation of the Stationary Source. 

Secondary Emissions do not include any emissions which come directly from a mobile 

source such as emissions from the tailpipe of a Motor Vehicle, from a train, or from a 

vessel.

SECONDARY INDUSTRIAL MATERIALS: products or by-products of the paint 

manufacturing process that are of known composition and have economic value but can 

no longer be used for their intended purpose.

SEMITRANSPARENT COATING: a Coating that contains binders and colored pigments 

and is formulated to change the color of the surface, but not conceal the grain pattern or 

texture.

SEMI-TRANSPARENT STAINS: Coatings which are formulated to change the color of a 

surface but not conceal the surface.

SEMI-TRANSPARENT WOOD PRESERVATIVES: Wood Preservative Stains 

formulated and used to protect exposed wood from decay or insect attack by the 

addition of a Wood Preservative chemical registered by the California Department of 

Food and Agriculture, which change the color of a surface but do not conceal the 

surface, including clear Wood Preservatives.

SHELLAC: a clear or opaque Coating formulated solely with the resinous secretions of 

the lac beetle (Laciffer lacca), and formulated to dry by evaporation without a chemical 

reaction.

SHOP APPLICATION: application of a Coating to a product or a component of a 

product in or on the premises of a factory or a shop as part of a manufacturing, 

production, or repairing process (e.g., original Equipment manufacturing Coatings).

SHUTDOWN: means an action necessary to cease operation of an Emissions Unit and 

includes the amount of time needed to safely do so. For the purposes of calculating 

ERC's, means the Permanent cessation of emissions from an emitting unit and the 
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surrender of the operating permit.

SIGNIFICANT: in reference to an Emissions Increase or the potential of a Source to 

emit any of the following pollutants, a rate of emissions that would equal or exceed any 

of the following rates:

1. PM2.5: 10 tpy of direct PM2.5 or 40 tpy of sulfur dioxide emissions or 40 tpy of 

nitrogen oxide emissions.

2. Nitrogen oxides: 40 tpy

3. Sulfur dioxide: 40 tpy

4. VOC's: 40 tpy; and

5. PM10: 15 tpy

SIGNIFICANT EMISSIONS INCREASE: an increase in emissions that is Significant for 

that pollutant.

SIGNIFICANT NET EMISSIONS INCREASE: an increase in net emissions that is 

Significant for that pollutant. The “net emissions increase” shall be determined as 

defined in 40 CFR 51.165.

SINGLE-STAGE COATING: any pigmented Coating, excluding Primers and Multi-Color 

Coatings, labeled and formulated for application without a subsequent clear coat. 

Single-stage Coatings include single-stage metallic/iridescent Coatings.

SOAP BUBBLE SCORE: the magnitude of a leak as indicated by the size of bubble 

formation resulting from spraying the suspected area with a standard solution. Soap 

scores are assigned following six seconds of observation as follows:

Soap Score Estimate Bubble Volume (cc/6 Sec.)

0 No detectable bubbling

1 0 to 1 cc per 6 sec.

2 1 to 10 cc per 6 sec.

3 10 to 100 cc per 6 sec.

4 Greater than 100 cc per 6 sec.

SOLICIT: to require for use or to specify, by written or oral contract.

SOLVENT: for purposes of Rule 427, a VOC-containing fluid used to perform cleaning 

operations.

SOURCE: a specific device, article, or piece of Equipment from which Air Contaminants 
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are emitted, or the distinct place (such as with fires or other chemical activity) from 

which Air Contaminants are emitted. A Project or facility may have more than one 

Source and the term may be used to describe a group of "Sources."

SPACE VEHICLE: a vehicle designed for use beyond the earth's Atmosphere.

SPECIALTY COATING: a Coating used for limited, specialty applications, such as 

Camouflage Coatings or extreme performance Coatings. Such Coatings frequently 

have no complying counterpart, and often must be used to fulfill specific performance 

requirements of the particular Coating application.

SPECIALTY PRIMER, SEALER, AND UNDERCOATER: a Coating that is formulated 

for application to a substrate to block water-soluble Stains resulting from: fire damage; 

smoke damage; or water damage. Specialty Primers, Sealers, and Undercoaters must 

be labeled in accordance with Rule 424, subsection E.8. Until January 1, 2012, the 

Specialty Primer, Sealer, and Undercoater includes Coatings formulated to seal 

excessively chalky surfaces. An excessively chalky surface is one that is defined as 

having a chalk rating of four or less as determined by ASTM D4214-98, incorporated by 

reference in Rule 424, subsection G.5.g.

SPOT REPAIR: repair of an area on a Motor Vehicle, piece of Mobile Equipment, or 

associated parts or components of less than 1 square foot (929 square centimeters). 

SPRAY SAFETY SWITCH: safety switch which cuts off the spray applicator pump if 

vapor levels drop below a specific level.

STACK-GAS OXYGEN SYSTEM: means a system of monitors that is used to maintain 

excess air at the desired level. A typical system consists of a flue gas oxygen and/or 

carbon monoxide monitor that automatically provides a feedback signal to the 

combustion air controller.

STAIN: a semi-transparent, or opaque Coating labeled and formulated to change the 

color of a surface but not conceal the grain pattern or texture.

STANDARD CONDITIONS: a gas temperature of 60 degrees Fahrenheit and a gas 

pressure of 14.7 pounds per square inch absolute. Results of all analyses and tests 

shall be calculated or reported at this gas temperature and pressure.

STARTUP: means an action necessary to begin operation of a unit and includes the 

amount of time needed for a unit and ancillary Equipment to achieve stable operations.

STATE BOARD: the California Air Resources Board, or any Person authorized to act on 

its behalf.

STATIONARY GAS TURBINE(S): means any gas turbine system, with or without power 

augmentation, which is permanently attached to a foundation, or is not a portable gas 
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turbine. Two or more gas turbines powering a common shaft shall be treated as one 

gas turbine. 

STATIONARY SOURCE: any building, structure, facility, Equipment, or Emissions Unit 

which emits or may emit any Affected Pollutant directly or as a Fugitive Emission. 

Building, structure, or facility includes all pollutant emitting activities, including Emission 

Units, which:

1. are located on one or more contiguous or adjacent properties, and

2. are under the same or common ownership or operation, or which are owned or 

operated by entities which are under common control, and

3. belong to the same industrial grouping either by virtue of falling within the same 

two-digit standard industrial classification code or by virtue of being part of a 

common production process, industrial process, manufacturing process, or 

connected process involving a common raw material.

STATIONARY TANK: any tank, reservoir or other container used to store, but not 

transport, Reactive Organic Compounds.

STENCIL COATING: for the purposes of Rule 425, means an ink or Coating which is 

rolled, sprayed with an airbrush or a touch-up gun with a capacity of 8 ounces (236.4 

ml) or less, or brushed using a template to add identifying letters and/or numbers to 

Aerospace Component.

STONE CONSOLIDANT: a Coating that is labeled and formulated for application to 

stone substrates to repair historical structures that have been damaged by weathering 

or other decay mechanisms. Stone Consolidants must penetrate into stone substrates 

to create bonds between particles and consolidate deteriorated material. Stone 

Consolidants must be specified and used in accordance with ASTM E2167-01, 

incorporated by reference in Rule 424, subsection G.5.x. Stone Consolidants are for 

professional use only and must be labeled as such, in accordance with the labeling 

requirements in Rule 424, subsection E.11.

STRIPPER: a Reactive Organic Compound liquid applied to remove a Maskant, paint, 

paint residue or temporary protective Coating.

SUBMERGED FILL PIPE: any permanent fill pipe which has its discharge opening 

entirely submerged when the liquid level is six inches above the bottom of the tank. 

“Submerged Fill Pipe” when applied to a tank which is loaded from the side means any 

fill pipe which has its discharge opening entirely submerged when the liquid level is 18 

inches above the bottom of the tank. 

SURFACE PREPARATION SOLVENT: any Solvent used primarily for the conditioning 

of a surface to receive a Coating.
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SURPLUS: the amount of emission reductions that are, at the time of generation of an 

ERC, not otherwise required by federal, State, or local law, not required by any legal 

settlement or consent decree, and not relied upon to meet any requirement related to 

the California SIP. For the purpose of Rule 207, sections C.2.c and C.2.d, “Surplus” 

means the amount of emission reductions that are, at the time of use of an ERC, not 

otherwise required by federal, State, or local law, not required by any legal settlement or 

consent decree, and not relied upon to meet any requirement related to the California 

SIP. However, emission reductions required by a state statute that provides that the 

subject emission reductions shall be considered Surplus may be considered Surplus for 

purposes of Rule 207 if those reductions meet all other requirements of Rule 207. 

Examples of federal, State, and local laws and of SIP-related requirements include, but 

are not limited to, the following:

1. the federally-approved California SIP;

2. other adopted State air quality laws, and regulations not in the SIP, including but 

not limited to, any requirement, regulation, or measure that : (1) the District or the 

State has included on a legally-required and publicly-available list of measures 

that are scheduled for adoption by the District or the State in the future; or (2) is 

the subject of a public notice distributed by the District or the State regarding an 

intent to adopt such revision;

3. any other Source or Source-category specific regulatory or permitting 

requirement, including, but not limited to, RACT, New Source Performance 

Standards (NSPS), National Emission Standards for Hazardous Air Pollutants

(NESHAP), Best Available Control Measures (BACM), BACT, and the Lowest 

Achievable Emission Rates (LAER); and

4. any regulation or supporting documentation that is required by the CAA but is not 

contained or referenced in 40 CFR Part 52, including but not limited to: 

assumptions used in attainment and maintenance demonstrations (including 

Reasonable Further Progress demonstrations and milestone demonstrations), 

including any proposed control measure identified as potentially contributing to 

an Enforceable near-term emissions reduction commitment; assumptions used in 

conformity demonstrations, and assumptions used in emissions inventories.

5. emission reductions produced by monies from any public air quality related 

funding program including but not limited to the Carl Moyer Memorial Air Quality 

Standards Attainment Program and the vehicle registration surcharge fee.

SWIMMING POOL COATING: a Coating labeled and formulated to coat the interior of 

swimming pools and to resist swimming pool chemicals. Swimming Pool Coatings 

included Coatings used for swimming pool repair and maintenance.

SWIMMING POOL REPAIR AND MAINTENANCE COATING: a rubber based Coating
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labeled and formulated to be used over existing rubber based Coatings for the repair 

and maintenance of swimming pools. Effective January 1, 2011, a Coating meeting this 

definition will be subject to the applicable category in Table 424-2, except as provided in 

subsection D.2, Most Restrictive VOC Limits found in Rule 424.

SWITCH LOADING: the loading of organic liquids with a Reid vapor pressure of less 

than 4.0 pounds into a delivery vessel where the previous load was gasoline.

TACK COAT: any application of Asphalt applied to an existing surface to provide a bond 

between new surfacing and an existing surface and to eliminate slippage planes where 

the new and existing surfaces meet.

TANK REPLACEMENT: the replacement of one or more stationary Gasoline storage 

tanks at an existing Gasoline dispensing facility, or, the excavation of 50 percent or 

more of an existing Gasoline dispensing facility's total underground liquid Gasoline

piping from the stationary storage tanks to the Gasoline dispensers.

TEMPERATURE-INDICATOR SAFETY COATING: a Coating labeled and formulated 

as a color-changing indicator Coating for the purpose of monitoring the temperature and 

safety of the substrate, underlying piping, or underlying Equipment, and for application 

to substrates exposed continuously or intermittently to temperatures above 400°F 

(204°C). Effective January 1, 2011, a Coating meeting this definition will be subject to 

the applicable category in Table 424-2, except as provided in subsection D.2, Most 

Restrictive VOC Limits found in Rule 424.

TEMPORARY PROTECTIVE COATING: for the purposes of Rule 427, any Coating

which is labeled and formulated for the purpose of temporarily protecting areas from 

overspray or mechanical damage. 

THERMAL OXIDIZER: means combustion Equipment fired with Gaseous Fuel and used 

to control emissions of Air Contaminants from industrial or commercial processes.

THERMO CONTROL COATING: a Coating applied to Space Vehicle components to 

reflect heat and formulated to give specific heat reflectance, absorption and emissivity 

properties, or a Coating required for aerospace engine components to delay component 

failure due to fire.

TINT BASE: an Architectural Coating to which colorant is added after packaging in sale 

units to produce a desired color.

TOPCOAT: a Coating applied over a Primer as the final coat for purposes such as 

appearance, identification, or protection.

TOTAL REDUCED SULFUR COMPOUNDS: the sulfur compounds methyl mercaptan, 

dimethyl sulfide, dimethyl disulfide, carbon disulfide, and carbonyl sulfide.
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TOUCH-UP COATING: for the purposes of Rule 425, means a Coating that is used for 

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. A touch-up 

Coating may include small amounts of Solvent, applied by hand, used to attach Coating

patches exhibiting inadequate adhesion.

TOXIC AIR CONTAMINANT: an air pollutant which may cause or contribute to an 

increase in mortality or an increase in serious illness or which may pose a present or 

potential hazard to human health. This includes, but is not limited to, hazardous air 

pollutants listed in Section 112(b) of the Clean Air Act, which is incorporated by 

reference.

TRAFFIC MARKING COATING: a Coating labeled and formulated for marking and 

striping streets, highways, or other traffic surfaces including, but not limited to, curbs, 

berms, driveways, parking lots, sidewalks, and airport runways.

TRANSFER: in reference to ERC's, means the conveyance of an ERC from one entity 

to another

TRANSFER EFFICIENCY: is the amount of Coating solids adhering to the object being 

coated divided by the total amount of Coating solids sprayed, expressed as a 

percentage.

TREATED BRUSH: material to be burned that has been felled, crushed or uprooted 

with mechanical Equipment, or desiccated with herbicides.

TRUCK BED LINER COATING: any Coating, excluding clear, color, multi-color, and 

single stage Coatings, labeled and formulated for application to a truck bed to protect it 

from surface abrasion.

TUB AND TILE REFINISH COATING: a clear or opaque Coating that is labeled and 

formulated exclusively for refinishing the surface of a bathtub, shower, sink, or 

countertop. Tub and Tile Refinish Coatings must meet all of the following criteria:

1. the Coating must have a scratch hardness of 3H or harder and a gouge hardness 

of 4H or harder. This must be determined on bonderite 1000, in accordance with 

ASTM D3363-05, incorporated by reference in Rule 424, subsection G.5.p and

2. the Coating must have a weight loss of 20 milligrams or less after 1000 cycles. 

This must be determined with CS-17 wheels on bonderite 1000, in accordance 

with ASTM D4060-07 incorporated by reference in Rule 424, subsection G.5.q

and

3. the Coating must withstand 1000 hours or more of exposure with few or no #8 

blisters. This must be determined on unscribed bonderite, in accordance with 

ASTM D4585-99 and ASTM D714-02e1, incorporated by reference in Rule 424, 
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subsection G.5.r and

4. the Coating must have an adhesion rating of 4B or better after 24 hours of 

recovery. This must be determined on unscribed bonderite, in accordance with 

ASTM D4585-99 and ASTM D3359-02, incorporated by reference in Rule 424, 

subsection G.5.o. 

ULTRASONIC: enhancement of cleaning process by vibrating Organic Solvent with high 

frequency sound waves, causing implosion of microscopic vapor cavities within liquid 

Organic Solvent.

UNDERBODY COATING: for purposes of Rule 427, any Coating labeled and 

formulated for application to wheel wells, the inside of door panels or fenders, the 

underside of a trunk or hood, or the underside of the Motor Vehicle.

UNIFORM FINISH COATING: for purposes of Rule 427, any Coating labeled and 

formulated for application to the area around a Spot Repair for the purpose of blending 

a repaired area’s color or clear coat to match the appearance of an adjacent area’s 

existing Coating.

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY (US EPA): the 

Administrator or appropriate delegate of the "United States Environmental Protection 

Agency."

UNRESERVED FUND BALANCE: the excess of the assets of a governmental fund or 

trust fund over its liabilities and fund balance reserved accounts.

UPWIND: the area bounded by a line drawn perpendicular to the predominant wind flow 

line passing through or nearest to the site of the new source or Modification and 

extending to the boundaries of the same or adjoining counties within the same air basin 

except where the APCO determines that for reasons of topography or meteorology such 

a definition is inappropriate.

VAPOR LEVEL CONTROL THERMOSTAT: safety switch which turns off sump heater if 

temperature rises above design operating level at center of air-vapor interface.

VAPOR RECOVERY SYSTEM: a vapor-gathering system capable of collecting organic 

vapors and gases emitted during the operation of Equipment.

VAPOR TIGHT: for the purposes of Rule 415, means a leak of less than 100 percent of 

the lower explosive limit on a combustible gas detector measured at a distance of 2.5 

cm (1 in) from the Source or no visible evidence of air entrainment in the sight glasses 

of liquid delivery hoses.

VARIANCE: an authorization by the Hearing Board to permit, for a specified limited 

period of time, some act contrary to the requirements specified by the District Rules and 
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regulations.

VARNISH: a clear or semi-transparent Wood Coating, excluding Lacquers and 

Shellacs, formulated to dry by chemical reaction on exposure to air. Varnishes may 

contain small amounts of pigment to color a surface, or to control the final sheen or 

gloss of the Finish. Effective January 1, 2011, a Coating meeting this definition will be 

subject to the applicable category in Table 424-2, except as provided in subsection D.2, 

Most Restrictive VOC Limits found in Rule 424. 

VEHICLE CLASS: either a Passenger Car, Light Duty Truck, Medium Duty Vehicle or 

Heavy Duty Vehicle as defined in Title 13 California Code of Regulation section 1900.

VENEER: thin sheets of wood peeled or sliced from logs for use in the manufacture of 

wood products such as plywood, laminated Veneer lumber, or other products.

VIRGIN MATERIALS: materials that contain no post-consumer Coatings or secondary 

industrial materials.

VOLATILE FUEL: any fuel having a Reid vapor pressure of greater than 3.0 pounds per 

square inch when tested pursuant to the American Society of Testing and Materials 

(ASTM) Reid Vapor Pressure test method, or having a true vapor pressure of greater 

than 3.0 pounds per square inch absolute at 100°F if the ASTM Reid Vapor Pressure 

test is not applicable.

VOLATILE ORGANIC COMPOUND (VOC): any volatile compound containing at least 

one atom of carbon, excluding carbon monoxide, carbon dioxide, carbonic acid, metallic 

carbides or carbonates, and ammonium carbonate, and excluding the following:

1. methane;

methylene chloride (dichloromethane);

1,1,1-trichloroethane (methyl chloroform);

trichlorofluoromethane (CFC-11);

dichlorodifluoromethane (CFC-12);

1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113);

1,2-dichloro-1,1,2,2-tetrafluoroethane (CFC-114);

chloropentafluoroethane (CFC-115);

chlorodifluoromethane (HCFC-22);

2,2-dichloro-1,1,1-trifluoroethane (HCFC-123);

2-chloro-1,1,1,2-tetrafluoroethane (HCFC-124);

1,1-dichloro-1-fluoroethane (HCFC-141b);

1-chloro-1,1-difluoroethane (HCFC-142b);

trifluoromethane (HFC-23);

pentafluoroethane (HFC-125);

1,1,2,2-tetrafluoroethane (HFC-134);

1,1,1,2-tetrafluoroethane (HFC-134a);

1,1,1-trifluoroethane (HFC-143a);
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1,1-difluoroethane (HFC-152a);

cyclic, branched, or linear completely methylated siloxanes;

the following classes of perfluorocarbons:

(A) cyclic, branched, or linear, completely fluorinated alkanes;

(B) cyclic, branched, or linear, completely fluorinated ethers with no 

unsaturations;

(C) cyclic, branched, or linear, completely fluorinated tertiary amines with no 

unsaturations; and

(D) sulfur-containing perfluorocarbons with no unsaturations and with the 

sulfur bonds only to carbon and fluorine; and

2. the following low Reactive Organic Compounds which have been exempted by 

the US EPA:

acetone;

ethane;

parachlorobenzotrifluoride (1-chloro-4-trifluoromethyl benzene);

perchloroethylene;

methyl acetate; 

propylene carbonate and 

dimethyl carbonate

3. Perfluorocarbon and Methylated Siloxane compounds shall be assumed to be 

absent from any product or process unless the manufacturer or operator 

indicates which specific, individual compounds from these broad classes are 

present, indicated the amount(s) present, and demonstrates the availability of a 

test method approved by the US EPA, the CARB, and the District for verifying 

the amount(s) present quantitatively.

4. Tertiary-Butyl Acetate (also known as t-butyl acetate, TBAC or TBAc) shall be 

considered exempt as a VOC only for purposes of VOC emissions limitations or 

VOC content requirements, but will continue to be a VOC for purposes of all 

recordkeeping, emissions reporting, photochemical dispersion modeling, and 

inventory requirements with apply to VOC's. 

VOC ACTUAL: VOC Actual is the weight of VOC per volume of Coating and it is 

calculated with the following equation:

VOC Actual = (Ws-Ww-Wec)

(Vm)

Where:

VOC Actual = the grams of VOC per liter of Coating (also known as “Material 

VOC”)

Ws = weight of volatiles, in grams

Ww = weight of water, in grams
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Wec = weight of exempt compounds, in grams

Vm = volume of Coating, in liters

VOC CONTENT: the weight of VOC per volume of Coating. VOC Content is VOC 

Regulatory, as defined within this rule under VOC Regulatory, for all Coatings except 

those in the Low Solids category. For Coatings in the Low Solids category, the VOC 

Content is VOC Actual, as defined within this rule under VOC Actual. If the Coating is a 

multi-component product, the VOC content is VOC Regulatory as mixed or catalyzed. If 

the Coating contains silanes, siloxanes, or other ingredients that generate ethanol or 

other VOCs during the curing process, the VOC content must include the VOCs emitted 

during curing.

VOC REGULATORY: VOC Regulatory is the weight of VOC per volume of Coating, less 

the volume of water and exempt compounds. It is calculated with the following 

equation:

VOC Regulatory = (Ws-Ww-Wec)

(Vm-Vw-Vec)

Where:

VOC Regulatory = grams of VOC per liter of Coating, less water and exempt 

compounds (also known as “Coating VOC”)

Ws = weight of volatiles, in grams

Ww = weight of water, in grams

Wec = weight of exempt compounds, in grams

Vm = volume of Coating, in liters

Vw = volume of water, in liters

Vec = volume of exempt compounds, in liters

WASTE HEAT RECOVERY BOILER: means Waste Heat Recovery Boilers used to 

recover sensible heat from unfired Waste Heat Recovery Boilers and from the exhaust 

of any combustion Equipment. 

WATER TREATMENT ADDITIVES: any combination of chemicals used to treat cooling 

tower water. They include, but are not limited to, corrosion inhibitors antiscalants, 

dispersants and biocides.

WATERPROOFING CONCRETE/MASONRY SEALER: a clear or pigmented filmforming Coating that is labeled and formulated for sealing concrete and masonry to 

provide resistance against water, alkalis, acids, ultraviolet light, and staining. Effective 

January 1, 2011, a Coating meeting this definition will be subject to the applicable 

category in Table 424-2, except as provided in subsection D.2, Most Restrictive VOC 

Limits found in Rule 424. 

WATERPROOFING MEMBRANE: a clear or opaque Coating that is labeled and 

formulated for application to concrete and masonry surfaces to provide a seamless 
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waterproofing membrane that prevents any penetration of liquid water into the 

substrate. Waterproofing Membranes are intended for the following waterproofing 

applications: below-grade surfaces, between concrete slabs, inside tunnels, inside 

concrete planters, and under flooring materials. Waterproofing Membranes must meet 

the following criteria:

1. Coating must be applied in a single coat of at least 25 mils (at least 0.025 inch) 

dry film thickness; and

2. Coatings must meet or exceed the requirements contained in ASTM C836-06, 

incorporated by reference in Rule 424, subsection G.5.s.

The Waterproofing Membrane category does not include Topcoats that are included in 

the Concrete/Masonry Sealer category (e.g., parking deck Topcoats, pedestrian deck 

Topcoats, etc.).

WATERPROOFING SEALER: a Coating labeled and formulated for application to a 

porous substrate for the primary purpose of preventing the penetration of water. 

Effective January 1, 2011, a Coating meeting this definition will be subject to the 

applicable category in Table 424-2, except as provided in subsection D.2, Most 

Restrictive VOC Limits found in Rule 424. 

WIPE CLEANING: method of cleaning which utilizes a cloth, cotton swab or other 

material, wetted with an Organic Solvent, which is physically rubbed on surface to be 

degreased.

WOOD COATINGS: Coatings labeled and formulated for application to Wood 

Substrates only. The Wood Coatings category includes the following clear and 

semitransparent Coatings: Lacquers; Varnishes; Sanding Sealers; penetrating oils; 

clear Stains; wood conditioners used as undercoats; and wood sealers used as 

Topcoats. The Wood Coatings category also includes the following opaque wood 

Coatings: opaque Lacquers; opaque Sanding Sealers; and opaque Lacquer

undercoaters. The Wood Coatings category does not include the following: clear 

sealers that are labeled and formulated for use on concrete/masonry surfaces; or 

Coatings intended for substrates other than wood.

Wood Coatings must be labeled “For Wood Substrates Only”, in accordance with Rule 

424, subsection E.13.

WOOD PRESERVATIVE: a Coating labeled and formulated to protect exposed wood 

from decay or insect attack, that is registered with both the US EPA under the Federal 

Insecticide, Fungicide, and Rodenticide Act (7 United States Code (U.S.C.) Section 136, 

et seq.) and with the California Department of Pesticide Regulation.

WOOD SUBSTRATE: a substrate made of wood, particleboard, plywood, medium 

density fiberboard, rattan, wicker, bamboo, or composite products with exposed wood 
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grain. Wood Products do not include items comprised of simulated wood.

ZINC-RICH PRIMER: a Coating that meets all of the following specifications:

1. Coating contains at least 65 percent metallic zinc powder or zinc dust by weight 

of total solids; and

2. Coating is formulated for application to metal substrates to provide a firm bond 

between the substrate and subsequent applications of Coatings; and

3. Coating is intended for professional use only and is labeled as such, in 

accordance with the labeling requirements in Rule 424, subsection E.14.