RULE 4605 AEROSPACE ASSEMBLY AND COMPONENT COATING OPERATIONS 

(Adopted December 19, 1991; Amended May 21, 1992; Amended December 17, 

1992; Amended March 31, 1993; Amended February 17, 1994; Amended 

December 19, 1996; Amended December 20, 2001; Amended September 20, 

2007; Amended June 16, 2011) 

1.0 Purpose 

The purpose of this rule is to limit the emissions of volatile organic compounds (VOCs) 

from aerospace coatings and adhesives, from the organic solvent cleaning, and the 

storage and disposal of solvents and waste solvent materials associated with the use of 

aerospace coatings and adhesives and to provide the administrative requirements for 

recording and measuring the emissions. 

2.0 Applicability 

This rule shall apply to the manufacturing, assembling, coating, masking, bonding, paint 

stripping, surface cleaning, service, and maintenance of aerospace components, the 

cleanup of equipment, and the storage and disposal of solvents and waste solvent 

materials associated with these operations. 

3.0 Definitions 

3.1 Ablative Coating: a coating that chars when exposed to open flame or extreme 

temperatures, as would occur during the failure of an engine casing or during 

aerodynamic heating. The ablative char surface serves as an insulative barrier, 

protecting adjacent components from the heat or open flame. 

3.2 Adhesion Promoter: a coating applied to a substrate in a monomolecular thickness 

to promote wetting and form a chemical bond with the subsequently applied 

material. 

3.3 Adhesive: a substance that is used to bond one surface to another. 

3.4 Adhesive Bonding Primer: a coating applied in a very thin film to aerospace 

adhesive bond detail components for corrosion inhibition and adhesion. 

3.5 Aerosol Coating: a mixture of pigments, resins, and liquid and gaseous solvents 

and propellants packaged in a disposable container for hand-held application. 

3.6 Aerospace Component: any raw material, partial or completed fabricated part, 

assembly of parts, or completed unit of any aircraft, helicopter, missile, or space 

vehicle, including mockups and prototypes. 
 

   

3.7 Aerospace Material: any coating, primer, adhesive, sealant, maskant, lubricant, 

stripper or hand-wipe cleaning or clean-up solvent used during the 

manufacturing, assembly, refinishing, maintenance or service of an aerospace 

component. 

3.8 Antichafe Coating: a coating applied to areas of moving aerospace components 

which may rub during normal operation. 

3.9 Anti-wicking Wire Coating: the outer coating of a wire which prevents fluid 

wicking into the insulation of the wire. 

3.10 APCO: as defined in Rule 1020 (Definitions). 

3.11 ARB: California Air Resources Board. 

3.12 ASTM: American Society for Testing and Materials. 

3.13 Barrier Coating: a coating applied in a thin film to fasteners to inhibit dissimilar 

metal corrosion and to prevent galling. 

3.14 Bearing Coating: a coating applied to an antifriction bearing, a bearing housing, or 

the area adjacent to such a bearing in order to facilitate bearing function or to 

protect the base material from excessive wear. A material shall not be classified as 

a bearing coating if it can also be classified as a dry lubricative material or a solid 

film lubricant. 

3.15 Brush Coating: manual application of coatings using brushes and rollers. 

3.16 Caulking and Smoothing Compounds: a semi-solid materials which are applied by 

hand application methods and are used to aerodynamically smooth exterior vehicle 

surfaces or fill cavities such as bolt hole accesses. A material shall not be 

classified as a caulking and smoothing compound if it can also be classified as a 

sealant. 

3.17 Chemical Agent-resistant Coating (CARC): an exterior topcoat designed to 

withstand exposure to chemical warfare agents or the decontaminants used on these 

agents. 

3.18 Chemical Milling: the removal of metal by chemical action of acids or alkalis. 

3.19 Clear Topcoat: a clear or semi-transparent coating applied over a primer for 

purposes such as appearance, identification, or protection. 
 

   

3.20 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. 

3.21 Commercial Exterior Aerodynamic Structure Primer: a primer utilized for the 

purpose of extended corrosion protection, which is only used on the exterior of 

passenger and cargo doors, supporting door structures, aerodynamic components, 

and structures of commercial aircraft which protrude from the fuselage, such as 

wings and attached components, control surfaces, horizontal stabilizer, vertical 

fins, wing-to-body fairings, antennae, landing gear and landing gear doors. 

3.22 Conformal Coating: a coating applied to electrical conductors and circuit boards 

to protect them against electrical discharge damage and/or corrosion. 

3.23 Composite Partial Pressure: the sum of the partial pressures of the VOC 

compounds in a solvent. The VOC composite partial pressure is calculated as 

follows: 

∑ ∑

∑

= =

=

+ +

=

k

1

n

i 1

i

i

e

e

w

w

n

i 1

i

i i

c

MW

W

MW

W

MW

W

MW

(W )(VP )

PP

e

Where: 

Wi = Weight of the “i”th VOC compound, in grams 

Ww = Weight of water, in grams 

We = Weight of exempt compound, in grams 

MWi = Molecular weight of the “i”th VOC compound, 

 in grams per gram-mole 

MWw = Molecular weight of water, in grams per gram-mole 

MWe = Molecular weight of the “e”th exempt compound, 

 in grams per gram-mole 

PPc = VOC composite partial pressure at 20oC (68oF), in mm Hg 

VPi = Vapor pressure of the “i”th VOC compound at 20oC (68oF), 

 in mm Hg 

3.24 Decorative Laminate Primer: an adhesive bonding primer which is applied to a 

substrate to enhance adhesion between the decorative laminate and the 

subsequently applied substrate, and is cured at a maximum temperature of 250°F. 

3.25 Dip Coating: the process in which a substrate is immersed in a solution (or 

dispersion) containing the coating and then withdrawn. 
 

  
 

3.26 Dry Lubricative Coating: a coating consisting of lauric acid, cetyl alcohol, waxes, 

or other non-cross linked or resin-bound materials which act as a dry lubricant or 

protective coat. 

3.27 Electric-effect Coating: an electrically-conductive coating. 

3.28 Electrodeposition: a dip coating application method where the paint solids are 

given an electrical charge which is then attracted to a substrate. 

3.29 Electromagnetic Interference (EMI) Coating: a coating applied to space vehicles, 

missiles, aircraft radomes, and helicopter blades to disperse static energy or reduce 

electromagnetic interference. 

3.30 Electronic Wire Coating: the outer electrical insulation coating applied to tape 

insulation of a wire specifically formulated to smooth and fill edges. 

3.31 Electrostatic Application: a sufficient charging or atomized paint droplets to cause 

deposition principally by electrostatic attraction. This application shall be operated 

at a minimum 60 KV power. 

3.32 EPA: United States Environmental Protection Agency. 

3.33 Epoxy Based Fuel Tank Coating: a coating which contains epoxy resin that is 

applied to integral fuel tank components of aircraft to protect the fuel tank from 

corrosion and the by-products of bacterial growth. 

3.34 Fastener Sealant: a sealant applied to a device used to join two or more parts 

together. 

3.35 Fire Resistant Coating - Civilian (interior): a cabin interior coating that passes 

Federal Aviation Administration standards using the Ohio State University Heat 

Release, Fire and Burn Tests. 

3.36 Flight Test Coating: a coating applied to an aircraft prior to flight testing to 

protect the aircraft from corrosion and to provide required marking during flight 

test evaluation. 

3.37 Flow Coating: a coating application system with no air supplied to the nozzle and 

where paint flows over the part and the excess coating drains back into a collection 

system. 

3.38 Fuel Tank Adhesive: an adhesive used to bond components continuously exposed 

to fuel and which must be compatible with and used with fuel tank coatings. 
 

  
 

3.39 Fuel Tank Coating: a coating applied to the interior of a fuel tank or areas of an 

aircraft that are continuously wetted by fuel to protect it from corrosion and/or 

bacterial growth. 

3.40 Grams of VOC per Liter of Coating, Less Water and Exempt Compounds: the 

weight of VOC content per combined volume of VOC and coating solids and can 

be calculated by the following equation: 

Grams of VOC per liter of 

coating, less water and = Ws - Ww - Wec 

exempt compounds Vm - Vw - Vec 

Where, 

Ws = weight of volatile compounds (grams) 

Ww = weight of water (grams) 

Wec = weight of exempt compounds (grams) 

Vm = volume of material (liters) 

Vw = volume of water (liters) 

Vec = volume of exempt compounds (liters) 

3.41 Grams of VOC per Liter of Material: the weight of VOC per volume of material 

and can be calculated by the following equation: 

Grams of VOC per liter of material = Ws - Ww - Wec

Vm 

Where, 

Ws = weight of volatile compounds (grams) 

Ww = weight of water (grams) 

Wec = weight of exempt compounds (grams) 

Vm = volume of material (liters) 

3.42 Hand Application Methods: the application of coatings, sealants, or adhesives, by 

non-mechanical hand-held equipment including but not limited to paint brushes, 

hand rollers, caulking guns, trowels, spatulas, syringe daubers, rags and sponges. 

3.43 High Temperature Coating: a coating that is certified to withstand temperatures of 

more than 350°F. 

3.44 High-Volume, Low-Pressure (HVLP) Spray Equipment: equipment used to apply 

materials by means of a spray gun which is designed and intended to be operated, 

and which is operated, between 0.1 and 10.0 psig of air atomizing pressure 

measured dynamically at the center of the air cap and at the air horns, measured 

dynamically at the center of the air cap and the air horns. 
 

   

3.45 Impact Resistant Coating: a flexible coating that protects aerospace components, 

such as aircraft landing gear, and landing gear compartments, and other surfaces 

subject to abrasive impacts from runway debris. 

3.46 Intermediate Release Coating: a thin coating applied beneath topcoats to assist in 

removing the topcoat in depainting operations and generally to allow the use of less 

hazardous depainting methods. 

3.47 Lacquer: a clear or pigmented coating formulated with a nitrocellulose or synthetic 

resin to dry by evaporation without a chemical reaction. Lacquers are resoluble in 

their original solvent. 

3.48 Liquid Leak: a visible solvent leak from a container at a rate of more than three 

drops per minute, or a visible liquid mist. 

3.49 Long Term Adhesive Bonding Primer (Metal to Structural Core Bonding): an 

adhesive bonding primer that has met the aircraft manufacturers’ required 

performance characteristics following 6000 hours testing, used for metal to 

structural core bonding, and with an adhesive that is specified to be cured at 

350oF ± 10°F. 

3.50 Maskant for Chemical Milling: a coating applied directly to an aerospace 

component to protect surface areas when chemical milling such component. 

3.51 Metalizing Epoxy Coating: a coating that contains relatively large quantities of 

metallic pigmentation for appearance and/or added protection. 

3.52 Mold Release: a coating applied to a mold surface to prevent the molded piece 

from sticking to the mold as it is removed. 

3.53 Non-Absorbent Container: a container made of non-porous material that does 

not allow the migration of solvents through it. 

3.54 Non-Leaking Container: a container without liquid leak. 

3.55 Non-Structural Adhesive: an adhesive that bonds non-load carrying aircraft 

component in non-critical applications. 

3.56 Normal Business Hours: Monday through Friday, 8:00 am to 5:00 pm. 

3.57 Optical Anti-Reflective Coating: a coating with a low reflectance in the infrared 

and visible wavelength range and is used for anti-reflection on or near optical and 

laser hardware. 
 

   

3.58 Organic Solvent: the same as “Solvent.” 

3.59 Organic Solvent Cleaning: as defined in Rule 4663 (Organic Solvent Cleaning, 

Storage, and Disposal). 

3.60 Part Marking Coating: coatings or inks used to make identifying markings on 

materials, components, and/or assemblies. These markings may be either 

permanent or temporary. 

3.61 Phosphate Ester Resistant Wire Ink Coating: a coating that is used for surface 

identification or mark on aerospace wire or cable and which inhibits the corrosion 

caused by contact with phosphate ester type hydraulic fluids. 

3.62 Pretreatment Coating: a coating which contains no more than 12 percent solids by 

weight, and at least one-half (0.5) percent acid, by weight, to provide surface 

etching, and is applied directly to metal surfaces to provide corrosion resistance, 

adhesion and ease of stripping. 

3.63 Primer: a coating applied directly to an aerospace component for purposes of 

corrosion prevention, protection from the environment, functional fluid resistance 

and adhesion of subsequent coatings, adhesives, or sealants. 

3.64 Radiation-Effect Coating: a coating which helps in the prevention of radar 

detection. 

3.65 Rain Erosion Resistant Coating: a coating that protects leading edges, flaps, 

stabilizers, and engine inlet lips against erosion caused by rain during flight. 

3.66 Remanufactured Aircraft Part: an aerospace component that is built as a spare 

part or replacement part subject to an existing commercial aircraft specification. 

3.67 Rocket Motor Nozzle Coating: a catalyzed epoxy coating system used in 

elevated temperature applications on rocket motor nozzles. 

3.68 Roll Coating: application of coatings from a paint trough to a flat surface by 

mechanical series of rollers. 

3.69 Scale Inhibitor: a coating that is applied to the surface of a part prior to thermal 

processing to inhibit the formation of tenacious scale. 

3.70 SCAQMD: South Coast Air Quality Management District. 

3.71 Screen Print Ink: an ink used in screen printing processes during fabrication of 

decorative laminates and decals. 
 

   

3.72 Sealant: a viscous semisolid material that fills voids in order to seal out water, 

fuel, and other liquids and solids, and in some cases air movement, and is applied 

with a syringe, caulking gun, or spatula. 

3.73 Silicone Insulation Material: an insulating material applied to exterior metal 

surfaces for protection from high temperatures caused by atmospheric friction or 

engine exhaust. These materials differ from ablative coatings in that they are 

not “sacrificial”. 

3.74 Short Term Adhesive Bonding Primer: an adhesive bonding primer that has met 

the manufacturers’ required performance characteristics following 1000 hours 

testing, used for metal to metal and metal to structural core bonding, and with 

an adhesive which is specified to be cured at a temperature of 350oF ± 10°F. 

3.75 Solid Film Lubricant: a very thin coating consisting of a binder system containing 

as its chief pigment material one (1) or more of the following: molybdenum 

disulfide, graphite, polytetrafluoroethylene (PTFE) or other solids that act as a dry 

lubricant between closely-fitting surfaces. 

3.76 Solvent: as defined in Rule 4663 (Organic Solvent Cleaning, Storage, and 

Disposal). 

3.77 Sonic and Acoustic Applications: the use of aerospace materials on aerospace 

components that are subject to mechanical vibration and/or sound wave 

cavitation. 

3.78 Space Vehicle Coating: a coating applied to vehicles designed to travel and 

operate beyond earth's atmosphere. 

3.79 Specialized Function Coating: a coating that fulfills specific engineering 

requirements that are limited in application and are characterized by low volume 

usage. This category excludes coatings covered in other Specialty Coating 

categories. 

3.80 Stripper: a volatile liquid applied to remove a maskant for chemical processing, 

cured or dried paint, cured or dried paint residue or temporary protective coating. 

3.81 Structural Adhesive - Autoclavable: an adhesive used to bond load-carrying 

aircraft components and is cured by heat and pressure in an autoclave. 

3.82 Structural Adhesive - Nonautoclavable: an adhesive cured under ambient 

conditions and is used to bond load-carrying aircraft components or other critical 

functions, such as nonstructural bonding near engines. 
 

   

3.83 Surface Cleaning: any method of cleaning outside of a degreaser, including, but 

not limited to, wipe cleaning and equipment flushing. 

3.84 Temporary Protective Coating: a coating applied to an aerospace component to 

protect it from mechanical and environmental damage during manufacturing or 

shipping. 

3.85 Thermal Control Coating: a coating formulated with specific thermal conductive 

or radiative properties to permit temperature control of the substrate. 

3.86 Topcoat: a coating applied over a primer for purposes such as appearance, 

identification, or protection. 

3.87 Transfer Efficiency: the ratio of the weight or volume of coating solids adhering 

to the part being coated to the weight or volume of coating solids used in the 

application process, expressed as a percentage. 

3.88 Unicoat: a coating that is applied directly to an aerospace component for purposes 

of corrosion protection, environmental protection and functional fluid resistance 

that is not subsequently topcoated. A unicoat is used in lieu of the application of a 

primer and a topcoat. 

3.89 Volatile Organic Compounds (VOCs): as defined in Rule 1020 (Definitions). 

3.90 Waste Solvent Material: any solvent which may contain dirt, oil, metal 

particles, sludge, and/or waste products, or wiping material containing VOCs 

including, but not limited to, paper, cloth, sponge, rag, or cotton swab used in 

organic solvent cleaning. 

3.91 Wet Fastener Installation Coating: a primer or sealant applied by dipping, 

brushing, or daubing to fasteners that are installed before the coating is cured. 

3.92 Wing Coating: a coating that is corrosion resistant and is resilient enough to 

withstand the flexing of wings. 

3.93 Wire Prebonding Etchant: a non-additive surface treatment process to provide 

bondability of aerospace wire coatings to the underlying insulation layer. 

4.0 Exemptions 

4.1 Jet engine or rocket engine flushing operations using any solvent other than 

trichloroethylene are exempt from this rule. 
 

   

4.2 Except for the recordkeeping provisions of Sections 6.1.1 and 6.1.4, the 

requirements of Section 5.0 shall not apply to aerospace assembly and 

component coating operations using not more than four (4) gallons of products 

containing VOCs per day. Solvent-containing materials used in operations 

subject to Rule 4662 (Organic Solvent Degreasing Operations), shall not be 

included in this determination. 

4.3 Except for the provisions of Section 6.0, Section 5.0 shall not apply to laboratories 

which apply coatings, solvents, and adhesives to test specimens for purpose of 

research, development, quality control, and testing for production-related 

operations. Any person claiming this exemption shall provide operational records, 

data and calculations, as determined by the APCO to be necessary, to substantiate 

this claim. 

4.4 The provisions of Section 5.1 of this rule shall not apply to: 

4.4.1 Coatings or aerosols with separate formulations that are used in volumes of 

less than one (1) gallon on any day or 20 gallons in any calendar year at an 

aerospace assembly and component coating stationary source, or 

4.4.2 Adhesives with separate formulations that are used in volumes of less than 

one half (0.5) gallon on any day or ten (10) gallons in any calendar year at 

an aerospace assembly and component coating stationary source. 

Any operator seeking to claim the exemption in Section 4.4 shall notify the APCO 

in writing that substitute compliant coatings are not available. 

4.5 The provisions of Section 5.5 shall not apply to the application of coatings that: 

4.5.1 Contain less than 20 grams of VOC per liter of coating less water and 

exempt compounds, or 

4.5.2 Are dispensed from hand-held aerosol cans. 

5.0 Requirements 

5.1 Aerospace Coatings and Adhesives: After the applicable effective date indicated in 

Table 1, an operator shall not apply to any aerospace component any coating, 

aerosol or adhesive with a VOC content, less water and exempt compounds, as 

applied, in excess of the limits in Table 1. 
 

   

Table 1 – VOC Content Limits (Grams of VOC Per Liter of Coating [g/l], Less Water 

and Exempt Compounds) 

Product (VOC Containing Material) Before January 1, 

2013 

On and After 

January 1, 2013 

1. Ablative n/a 6001

2. Adhesion Promoter 850 850 

3. Adhesives 

a. Non-Structural 250 250 

b. Structural 

i. Autoclavable 50 50 

ii. Nonautoclavable 850 850 

4. Adhesive Bonding Primers 

a. New Commercial Aircraft 250 250 

b. All Military Aircraft 805 805 

c. Remanufactured Commercial Aircraft 

Parts 

805 805 

d. Sonic and Acoustic Applications 805 805 

e. Long Term 250 250 

f. Short Term 250 250 

5. Antichafe Coatings 600 600 

6. Barrier Topcoat 420 420 

7. Bearing Coating n/a 6201

8. Caulking and Smoothing Compounds n/a 8501

9. Chemical Agent Resistant Coating n/a 5501

10. Clear Topcoat 520 520 

11. Conformal Coating 750 750 

12. Dry Lubricative Materials 

a. Fastener Manufacturing 120 120 

b. Nonfastener Manufacturing 675 675 

13. Electric/Radiation Effect Coatings 800 800 

14. Electromagnetic Interference Coating n/a 8001

15. Fastener Sealants 675 6002

16. Fire Resistant Coatings 

a. Civilian (Interior) 650 650 
 

   

Table 1 – VOC Content Limits (Grams of VOC Per Liter of Coating [g/l], Less Water 

and Exempt Compounds) continued 

Product (VOC Containing Material) Before January 1, 

2013 

On and After 

January 1, 2013 

17. Flight Test Coatings Used on 

a. Missiles or Single-Use Target Craft 420 420 

b. All others 600 600 

18. Fuel Tank Coatings 

a. General 420 420 

b. Epoxy 420 420 

19. Fuel Tank Adhesives 620 620 

20. High Temperature Coating 850 850 

21. Impact Resistant Coating 420 420 

22. Intermediate Release Coating n/a 7501

23. Lacquer n/a 8301

24. Maskants - Chemical Milling 250 250 

25. Metalized Epoxy Coating n/a 7401

26. Mold Release n/a 7801

27. Optical Anti-Reflective Coating 700 700 

28. Part Marking Coating n/a 8501

29. Pretreatment Coatings 780 780 

30. Primers 

a. General 350 350 

b. Commercial Exterior Aerodynamic 

Structure 

350 350 

31. Rain Erosion Resistant Coating 800 800 

32. Rocket Motor Nozzle Coating n/a 6601

33. Scale Inhibitor 880 880 

34. Screen Prink Ink 840 840 

35. Sealant (Extrudable/Rollable/Brushable) 600 280

3

36. Silicone Insulation Material n/a 8501

37. Solid Film Lubricants 

a. Fastener Manufacturing 250 250 

b. Fastener Installation 880 880 

c. Nonfastener Manufacturing 880 880 

38. Space Vehicle Coatings 

a. Electrostatic Discharge Protection 800 800 
 

   

Table 1 – VOC Content Limits (Grams of VOC Per Liter of Coating [g/l], Less Water 

and Exempt Compounds) continued 

Product (VOC Containing Material) Before January 1, 

2013 

On and After 

January 1, 2013 

b. Other Space Vehicle Coatings 1000 1000 

c. Adhesives 800 800 

39. Specialized Function Coating n/a 8901

40. Temporary Protective Coatings 250 250 

41. Thermal Control Coating n/a 8001

42. Topcoats 420 420 

43. Epoxy Polyamide n/a 6601

44. Unicoats (Self Priming Topcoats) 420 420 

45. Wet Fastener Installation Coating n/a 6751

46. Wing Coating 750 750 

47. Wire Coatings 

a. Electronic 420 420 

b. Anti-Wicking 420 420 

c. Pre-Bonding Etching 420 420 

d. Phosphate Ester Resistant Ink 925 925 

1 Coatings that have been designated as “classified” by the Department of Defense or coatings that are 

used on space vehicles are exempt from these coating limits. 

2 Coatings that have been designated as “classified” by the Department of Defense or coatings that are 

used on space vehicles are exempt from the 600 g/l limit, but must comply with a 675 g/l limit. 

3

 Coatings that have been designated as “classified” by the Department of Defense or coatings that are 

used on space vehicles are exempt from the 280 g/l limit, but must comply with a 600 g/l limit.

5.2 Evaporative Loss Minimization 

5.2.1 Surface Cleaning: No operator shall use a solvent for surface cleaning, 

clean-up, or jet engine or rocket engine gas path cleaning or flushing, not 

exempt under Section 4.0 of this rule, excluding stripping coatings or 

cleaning coating application equipment, unless: 

5.2.1.1 the solvent contains less than 200 grams of VOC per liter (1.67 

lb/gal) of material, as applied; or 

5.2.1.2 the VOC composite vapor pressure of the solvent is less than or 

equal to 45 mm Hg (0.87 psia) at a temperature of 68°F. 

5.2.2 Coating Application Equipment Cleaning 
 

  
 

An operator shall not use VOC-containing materials to clean spray 

equipment used for the application of coatings, adhesives, or ink, unless 

an enclosed system or equipment that is proven to be equally effective at 

controlling emissions is used for cleaning. If an enclosed system is used, 

it must totally enclose spray guns, cups, nozzles, bowls, and other parts 

during washing, rinsing and draining procedures, and it must be used 

according to the manufacturer’s recommendations and must be closed 

when not in use. 

5.2.3 In lieu of compliance with Sections 5.2.1 or 5.2.2, an operator may 

control VOC emissions from surface cleaning operations or from 

cleaning coating application equipment with a VOC emission control 

system that meets the requirements of Section 5.6. 

5.3 Coating Strippers 

5.3.1 No operator shall use or specify for use within the District a coating 

stripper unless it contains less than 300 grams of VOC per liter (2.5 

lb/gal), as applied, or unless it has a VOC composite vapor pressure of 9.5 

mm Hg (0.18 psia) or less at 68°F. 

5.3.2 In lieu of compliance with Section 5.3.1, an operator may control 

emissions from coating stripper operations with a VOC emission control 

system that meets the requirements of Section 5.6. 

5.4 Storage and Disposal of VOC Containing Materials: An operator shall store or 

dispose of fresh or spent solvents, waste solvent cleaning materials such as 

cloth, paper, etc., coatings, adhesives, catalysts, and thinners in closed, nonabsorbent and non-leaking containers. The containers shall remain closed at all 

times except when depositing or removing the contents of the containers or 

when the container is empty. 

5.5 Application Equipment Requirements: No operator shall apply coatings subject to 

the provisions of this rule unless one (1) of the following methods is used: 

5.5.1 Electrostatic application; 

5.5.2 Electrodeposition; 

5.5.3 High-Volume, Low- Pressure (HVLP) spray, 

5.5.3.1 High-Volume, Low-Pressure (HVLP) spray equipment shall be 

operated in accordance with the manufacturer's 

recommendations. 
 

  
 

5.5.3.2 For HVLP spray guns manufactured prior to January 1, 1996, 

the end user shall demonstrate that the gun meets HVLP spray 

equipment standards. Satisfactory proof will be either in the 

form of manufacturer's published technical material or by a 

demonstration using a certified air pressure tip gauge, 

measuring the air atomizing pressure dynamically at the center 

of the air cap and at the air horns. 

5.5.3.3 A person shall not sell or offer for sale for use within the 

District any HVLP spray gun without a permanent marking 

denoting the maximum inlet air pressure in psig at which the 

gun will operate within the parameters specified in Section 3.0. 

5.5.4 Flow coating; 

5.5.5 Roll coating; 

5.5.6 Dip coating; 

5.5.7 Brush coating. 

5.5.8 In lieu of compliance with Sections 5.5.1 through 5.5.7, an operator may 

control VOC emissions from application equipment with a VOC 

emission control system that meets the requirements of Section 5.6. 

5.6 VOC Emission Control System 

As an alternative to meeting the requirements of Sections 5.1, 5.2, 5.3, or 5.5, an 

operator may install a VOC emission control system provided that the VOC 

emission control system meets all of the following requirements: 

5.6.1 The VOC emission control system shall be approved by the APCO. 

5.6.2 The VOC emission control system shall comply with the requirements of 

Sections 5.6.3 through 5.6.5 during periods of emission-producing 

activities. 

5.6.3 The VOC control system’s VOC control device shall have a control 

efficiency of at least 95 percent, by weight. 

5.6.4 The VOC emission control system’s VOC collection device(s) shall have a 

capture efficiency of at least 90 percent by weight. 
 

   

5.6.5 In no case shall compliance through the use of a VOC emission control 

system result in VOC emissions in excess of the VOC emissions which 

would result from compliance with applicable provisions of Sections 5.1, 

5.2, 5.3, or 5.5. 

5.6.6 The minimum required overall capture and control efficiency of an 

emission control system at which an equivalent or greater level of VOC 

reduction will be achieved shall be calculated by using the following 

equation: 

Where: 

CE = Minimum Required Overall Capture and Control 

Efficiency, percent 

VOCLWc = VOC Limit, less water and exempt compounds 

VOCLWn,Max = Maximum VOC content of noncompliant coating used in 

conjunction with a control device, less water and exempt 

compounds 

Dn,Max = Density of solvent, reducer, or thinner contained in the 

noncompliant coating, containing the maximum VOC 

content of the multi-component coating 

Dc = Density of corresponding solvent, reducer, or thinner 

used in the compliant coating system. 

5.7 Prohibition of Solicitation: No person shall solicit, specify, or require an operator 

to use any coating, solvent, spray equipment, or VOC emission control system that 

does not meet the limits or requirements of this rule. 

6.0 Administrative Requirements 

6.1 Recordkeeping 

6.1.1 An operator subject to the requirements of this rule shall have coating 

manufacturer's specifications, either listed on the coating container, 

product data sheet, or on Material Safety Data Sheets (MSDS), available 

for review and shall maintain daily records which show the following 

information as applicable: 

6.1.1.1 manufacturer name and type for each coating, solvent, thinner, 

reducer or stripper used, 

( )

( ) x 100

-1 VOC / D

-1 VOC / D

 x 

VOC

VOC CE = -1

LWc c

LWn, n,

LWn,

LWc 

























 Max Max

Max
 

   

6.1.1.2 mix ratio, by volume, of components added to the original 

material prior to application, 

6.1.1.3 grams of VOC per liter of each coating, solvent, thinner, reducer 

or stripper, less water and exempt compounds, as applied, 

6.1.1.4 grams of VOC per liter of each solvent, thinner, reducer, or 

stripper, 

6.1.1.5 volume and method of application of each coating, solvent, 

thinner, reducer or stripper applied, and 

6.1.1.6 vapor pressure of solvents used. 

6.1.2 An operator shall maintain records to support that the following coatings 

have been specified for their intended application.

6.1.2.1 adhesion promoter. 

6.1.2.2 antichafe coating. 

6.1.2.3 electric/radiation effect. 

6.1.2.4 fuel tank adhesive. 

6.1.2.5 high temperature coating. 

6.1.2.6 impact resistant coating. 

6.1.2.7 optical anti-reflective coating. 

6.1.2.8 rain erosion resistant wing coating. 

6.1.3 An operator using a VOC emission control system pursuant to Section 5.6 

as a means of complying with this rule shall maintain daily records of key 

system operating parameters and maintenance procedures which will 

demonstrate continuous operation and compliance of the VOC emission 

control system during periods of emission-producing activities. Key 

system operating parameters are those necessary to ensure compliance with 

VOC limits. The parameters may include, but are not limited to, 

temperatures, pressures, and flow rates. 

6.1.4 An operator shall retain records for a minimum of five (5) years, make 

the records available on site during normal business hours to the APCO, 

ARB, or EPA, and submit the records to the APCO, ARB, or EPA upon 

request. 

6.2 Test Methods 

6.2.1 Coating VOC content and solvent VOC content shall be determined using 

EPA Method 24 or its constituent methods. The VOC content of coatings 
 

   

containing exempt halogenated VOCs shall be determined by using the 

ARB Method 432 or SCAQMD Method 303 (Determination of Exempt 

Compounds). 

6.2.2 The solid content of pretreatment coatings shall be determined using EPA 

Method 24. The acid content of pretreatment coatings shall be determined 

using ASTM Method D1613 06 (Standard Test for Acidity of Volatile 

Solvents and Chemical Intermediates used in Paint, Varnish, Lacquer and 

Related Products). 

6.2.3 The test method for determining the fire resistance of an interior coating 

shall be Federal Aviation Administration-required Ohio State University 

Heat Release, Fire and Burn Tests. 

6.2.4 The VOC composite vapor pressure of a blended solvent shall be 

determined by quantifying the amount of each organic compound in the 

blend using gas chromatographic analysis SCAQMD Test Method 308 

(Quantitation of Compounds by Gas Chromatography) and by calculating 

the VOC composite vapor pressure of the solvent by summing the product 

of the vapor pressure of each pure component and its molar fraction. For 

the purpose of this calculation, the blend shall be assumed to be an ideal 

solution where Raoult's Law applies. The vapor pressure of each pure 

component shall be obtained from published reference manuals or 

handbooks. 

6.2.5 The VOC emissions from enclosed systems used to clean coating 

application equipment shall be determined by the manufacturer using the 

SCAQMD General Test Method for Determining Solvent Losses from 

Spray Gun Cleaning Systems. 

6.2.6 The control efficiency of a VOC emission control system’s control 

device(s) shall be determined using EPA Methods 2, 2A, 2C, or 2D for 

measuring flow rates and EPA Methods 25, 25A, or 25B for measuring the 

total gaseous organic concentrations at the inlet and outlet of the control 

device. EPA Method 18 or ARB Method 422 shall be used to determine 

the emissions of exempt compounds. 

6.2.7 The capture efficiency of a VOC emission control system’s collection 

device(s) shall be determined according to EPA’s “Guidelines for 

Determining Capture Efficiency,” January 9, 1995 and 40 CFR 51, 

Appendix M, Methods 204-204F, as applicable, or any other method 

approved by EPA, ARB, and the APCO. 
 

   

6.2.8 When more than one test method or set of test methods are specified for 

any emissions testing, a violation of any test established in Section 6.2 

shall constitute a violation of the rule. 
 

   

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