SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT 

 

Final Staff Report for 

 

PROPOSED AMENDED RULE 1162 - POLYESTER RESIN OPERATIONS 

July 8, 2005 

Deputy Executive Officer 

Planning, Rule Development & Area Sources 

Elaine Chang, DrPH 

Assistant Deputy Executive Officer 

Planning, Rule Development & Area Sources

Laki Tisopulos, Ph.D., P.E. 

Planning and Rules Manager 

VOC Rule Development 

Larry Bowen, P.E. 

AUTHOR: Helmy Sultan, Ph.D. - Air Quality Specialist 

REVIEWED BY: Edward M. Muehlbacher, P.E. - Program Supervisor 

 Frances Keeler, Senior Deputy District Counsel 
SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT 

GOVERNING BOARD 

Chair: WILLIAM A. BURKE, Ed.D. 

 Speaker of the Assembly Appointee 

Vice Chair: S. ROY WILSON, Ed.D. 

 Supervisor, Fourth District 

 Riverside County Representative 

MEMBERS:

MICHAEL D. ANTONOVICH 

Supervisor, Fifth District 

Los Angeles County Representative 

JANE W. CARNEY 

Senate Rules Committee Appointee 

BEATRICE J. S. LAPISTO-KIRTLEY 

Mayor, City of Bradbury 

Cities Representative, Los Angeles County/Eastern Region 

RONALD O. LOVERIDGE 

Mayor, City of Riverside 

Cities Representative, Riverside County 

GARY OVITT 

Supervisor, Fourth District 

San Bernardino County Representative 

JAN PERRY 

Councilmember, 9th District 

Cities Representative, Los Angeles County, Western Region 

MIGUEL PULIDO 

Mayor, City of Santa Ana 

Cities Representative, Orange County 

JAMES SILVA 

Supervisor, Second District

Orange County Representative 

CYNTHIA VERDUGO –PERALTA 

Governor’s Appointee 

DENNIS YATES 

Mayor, City of Chino 

Cities Representative, San Bernardino County 

 EXECUTIVE OFFICER

BARRY R. WALLERSTEIN, D.Env. 
Proposed Amended Rule 1162 i July 2005

 

 

TABLE OF CONTENTS 

Page

EXECUTIVE SUMMARY .................................................................................................1 

BACKGROUND .................................................................................................................2 

AFFECTED SOURCES ......................................................................................................3 

PROPOSED AMENDMENTS............................................................................................3 

CONTROL TECHNOLOGY ..............................................................................................4 

EMISSIONS INVENTORY AND EMISSIONS FOREGONE..........................................9 

COST IMPACTS...............................................................................................................14 

ENVIRONMENTAL ASSESSMENT ..............................................................................14 

SOCIOECONOMIC ANALYSIS .....................................................................................15 

COMPARATIVE ANALYSIS..........................................................................................15 

CONCLUSIONS AND RECOMMENDATIONS ............................................................15 

DRAFT FINDINGS...........................................................................................................18 

COMMENTS AND RESPONSES....................................................................................18 

REFERENCES ..................................................................................................................21 

ATTACHMENT A: FINAL REPORT FOR AQMD GEL COAT TESTING PROGRAM

ATTACHMENT B: UNIFIED EMISSION FACTORS TABLE, July 23, 2001 
Final Staff Report 

Proposed Amended Rule 1162 1 July 2005 

EXECUTIVE SUMMARY 

The proposed amendments for South Coast Air Quality Management District (AQMD) Rule 

1162 - Polyester Resin Operation will delete the requirement to apply gel coats solely with 

nonatomizing spray application for gel coats and improve rule language clarity. 

On July 1, 2003, Rule 1162 required composite fabricators to operate their nonatomizing spray 

application equipment at conditions that result in volatile organic compound (VOC) emissions at 

or below the values stated in the Unified Emission Factors (UEF) table attached to the rule. The 

industry had documented to the AQMD that they were experiencing difficulty in implementing 

the requirement to apply gel coat with nonatomizing spray application equipment. Rule 1162 

was last amended by the AQMD Governing Board on July 9, 2004, to extend the effective date 

of the requirement for gel coat nonatomizing spray application from July 1, 2004, to July 1, 

2005. The extension also allowed implementation of the March 2004, AQMD Governing Board 

directive to staff to conduct testing of equipment used in the nonatomizing spray application of 

gel coats (Rule 1132 Amendment Resolutions 2004) for the purpose of verifying the 

effectiveness of the nonatomizing application technique and selecting a more appropriate 

definition for it. 

In an effort to implement the Governing Board’s direction for testing, staff, in cooperation with 

American Composite Manufacturers Association (ACMA), spray equipment manufacturers, gel 

coat manufacturers, and major composite fabricators developed the AQMD Gel Coat Testing 

Program Protocol. The objective of the testing program was to develop a more appropriate and 

enforceable definition for the nonatomizing spray application technique of gel coats. Testing 

included VOC emission and surface quality measurements (porosity, gloss, orange peel and 

water resistance tests) of gel coat sprayed materials. The four (4) major spray equipment 

manufacturers participated in the testing program, which was conducted from August through 

October 2004. Volatile Organic Compound (VOC) emissions were measured by AQMD staff. 

Surface quality analyses were conducted by staff of California Polytechnic State University, San 

Luis Obispo. 

The Gel Coat Testing Program verified that the pressure at the tip of the spray gun is a critical 

parameter affecting emission rates and quality of the gel coat finish. Testing demonstrated that 

emission reductions from the use of nonatomizing spray equipment at levels suggested by UEF 

were not technically feasible. When operated at pressures necessary to obtain UEF in the rule, 

the product was inferior. When operated at pressures under which the product specifications 

could be met, the emission reductions obtained were not statistically significant. Based on the 

testing results, staff is proposing to delete the requirement of application gel coats solely with 

nonatomizing spray application techniques. 

The AQMD had previously estimated that the use of the nonatomizing application equipment 

would reduce VOC emissions from gel coats sprayed by Rule 1162 operations by approximately 

0.43 ton per day. Additionally, a small use exemption of one gallon per day per facility has been 

added for an application that has been demonstrated to require the use of air spray equipment. 

Therefore, this amendment will result in foregone VOC emissions reductions of 0.45 tons per 

day. 
Final Staff Report 

Proposed Amended Rule 1162 2 July 2005 

BACKGROUND 

Rule 1162 requires open molding composite fabricators in the AQMD to use nonatomizing spray 

application techniques in applying resins and gel coats by July 1, 2002 and July 1, 2005, 

respectively. Gel coat is a surface coating, formulated from quick-setting polyester resin, that 

provides a cosmetic enhancement and protection to the composite product. The emissions 

reduction of the nonatomizing spray application technique was documented in several studies, in 

particular, the Composite Manufacturers Association (CFA) and Clean Manufacturing 

Technology and Safe Materials Institute (CMTI) testing program. The CFA/CMTI studies 

included resins and gel coats in atomizing and nonatomizing applications. The CFA emission 

rates were measured as pounds of VOC per ton of sprayed gel coats or resins. The results were 

published in the UEF table (2001). UEF rates estimate the VOC emission reduction of the 

nonatomizing spray application technique of gel coats to be approximately 40% by weight as 

compared to the atomized applications. 

Rule 1162 (b) (19) defines the nonatomizing spray application technique as “any application 

technique in which resin or gel coat flows from the applicator, in a steady and observable 

coherent flow, without droplets, for a minimum distance of three (3) inches from the applicator 

orifices”. 

During the implementation of Rule 1162, gel coat nonatomizing spray applications encountered 

difficulties in achieving the required three (3) inches coherent flow, as specified in the definition.

Staff also confirmed the same difficulties during Rule 1162 Technical Assessment study 

(January 2003) that addressed the feasibility of gel coat nonatomizing application. 

On July 11, 2003, the AQMD Governing Board amended the effective date for nonatomizing 

spray application for gel coats in Rule 1162 from July 1, 2003, to July 1, 2004, to allow for more 

testing of the gel coat nonatomizing spray application technique. The Gel Coat Testing Program 

was scheduled to be completed in March 2004. However, on February 12, 2004, the spray 

equipment manufacturers unexpectedly withdrew from the program and the testing was 

suspended. 

On July 9, 2004, the AQMD Governing Board amended the effective date for the gel coat 

nonatomizing spray application requirement in Rule 1162 from July 1, 2004, to July 1, 2005, to 

allow for additional time to implement the Gel Coat Testing Program and develop an appropriate 

definition of the nonatomizing spray application technique of gel coat. At that time, an 

additional requirement was added that the nonatomizing spray application equipment be operated 

under conditions that ensure American Composite Manufacturers Association (ACMA) 

recommended UEF be obtained. 

Throughout 2004, staff in cooperation with the ACMA, spray equipment manufacturers, gel coat 

manufacturers and major composite fabricators developed and conducted the Gel Coat Testing 

Program from August through October 2004. These tests conclude that it is infeasible to meet 

the rule requirements with the technology specified. Staff does not have any indication that 

technology is being developed that will enable emission reductions anticipated for the rule to be 

obtained. The test report is included as Attachment A in this Staff Report. 
Final Staff Report 

Proposed Amended Rule 1162 3 July 2005 

AFFECTED SOURCES

Proposed Amended Rule 1162 applies to all composite operations in the AQMD, which include 

but are not limited to, the manufacturers of the following: 

• Bathtub, shower and vanity installations; 

• Hulls for recreational and commercial watercraft; 

• Bodies for recreational vehicles; 

• Building panels and appliances; 

• Sporting equipment and power tools; 

• Automotive, aerospace and aircraft components; and 

• Structural components for chemical process equipment and storage tanks. 

Based on the1998-99 AQMD Emissions Inventory, staff has identified 81 composite facilities in 

the AQMD subject to Rule 1162. The annual emissions inventory of these facilities, based on the 

UEF (1999), is estimated to be 7.98 tons per day of VOC. Additionally, the 1998-99 Emissions 

Inventory indicates that 24 of the composite facilities in the AQMD emit greater than 20 tons of 

VOC per year and utilize spray booth(s) in their operations. These 24 facilities represent 

approximately 78% of the total VOC emissions from composite operations in the AQMD. 

PROPOSED AMENDMENTS 

PAR 1162 includes the following amendments: 

 Add paragraphs (b)(1), (b)(4) and (b)(15), the definition of the air-assisted airless 

spray, electrostatic application and high-volume, low-pressure spray, respectively. 

These techniques and other similar application techniques that result in equivalent 

emission reductions are required to apply gel coat to an open mold surface. 

 Delete paragraph (b)(20), the definition of nonatomizing spray application technique 

of gel coat. This technique is allowed but no longer required to apply gel coat 

materials to an open mold surface, 

 Modify subparagraph (c)(1)(B) to delete the requirement of gel coat nonatomizing 

spray application technique, and the modified version of the U.S. EPA definition for 

nonatomizing application technique for gel coats as found in the National Emission 

Standard for Hazardous Air Pollutants (NESHAP) for Reinforced Plastic Composites 

Production (40CFR63 Subpart WWWW) and add the requirement to apply gel coats 

using any applicable nonatomizing applications techniques listed in subparagraph 

(c)(1)(A), air-assisted airless spray, electrostatic application or high-volume, low 

pressure spray application techniques. 

 Modify paragraph (c)(4) to read “...hand-held spray gun which has a container for 

resin or gel coat ...” The amendment clarifies that a hand-held spray gun can also be 

used for gel coat touch-up and repair since such processes can not be performed using 

a paint brush application. 
Final Staff Report 

Proposed Amended Rule 1162 4 July 2005 

 Add subdivision (h), a small usage exemption for the application of pin striping gel 

coat. This exemption will allow the use of air spray equipment in an application where 

lower emitting application techniques have not been successfully demonstrated to date. 

CONTROL TECHNOLOGY 

Generally for coatings, nonatomizing spray application techniques reduce VOC emissions by 

applying the sprayed materials at significantly lower spray gun operation pressures with 

relatively larger droplets, minimizing significantly the droplet numbers and their surface area, as 

compared to the atomized application. The nonatomizing application technologies include, 

nonatomizing spray application technologies, flow coaters, pressure-fed rollers, resin 

impregnators and hand lay-up. 

CFA/CMTI Studies 

Several recent studies were conducted to evaluate the control efficiency of the nonatomizing 

application technologies. CFA/CMTI studies represent the most comprehensive evaluation of 

the emission rates of gel coats and resins applications. These studied were conducted at the 

Clean Manufacturing Technology and Safe Materials Institute (CMTI), Purdue University. 

These studies indicated that the use of the nonatomizing spray application technique to apply gel 

coats at certain operating pressures achieves an average VOC emissions reduction of about 40 

percent, by weight. The emission rates of different applications of resins and gel coats were 

published in the UEF tables (1999 & 2001). The CFA/CMTI tests were conducted in a 

temperature controlled environment where the gel coat application temperature ranged from 69 

to 80oF. Also, the spray application performance or the surface quality of the composite products 

was not included in the DFA/CMTI tests. 

 

AQMD Gel Coat Testing Program

In 2004, the AQMD conducted the Gel Coat Testing Program. The objective of the testing 

program was to determine the minimum range of pressure values at the tip of the nonatomizing 

spray gun that produces gel coat sprayed products with a satisfactory surface quality. The 

surface quality of the applied gel coat was also to be no less than the surface quality achieved 

when using an atomizing spray gun in accordance with the composite industry standards and 

achieves the emissions rates stated in the UEF table (2001) for composite manufacturers 

operating in the AQMD. 

The program measured VOC emission rates, pressure at the tip of the spray gun and surface 

quality using air-assisted airless and nonatomizing spray application equipment. The gel coats 

sprayed included clear, san bright white, midnight blue and sandable gray gel coats. The AQMD 

tests utilized conditions as close to what are used in Southern California facilities as possible. 
Final Staff Report 

Proposed Amended Rule 1162 5 July 2005 

AQMD Gel Coat Testing Program Protocol - Comparison to CFA Protocol 

The AQMD determined that in order to meet the objective of the Gel Coat Testing Program, it 

was critical to develop a testing protocol that would yield results and subsequent conclusions that 

are representative of gel coat spray applications at composite manufacturing operations in the 

AQMD. Unlike many other regions of the United Sates where composite manufacturing 

operations are conducted in temperature controlled environments to address wider variations in 

ambient temperature and humidity, operations in the AQMD do not air condition the 

manufacturing work areas. To address the seasonal temperature variations in southern 

California, it is becoming common practice for composite manufacturers to heat their gel coat 

prior to application. The heating of the gel coat lowers the viscosity, which according to the 

manufacturers, improves the consistency of the flow characteristics of the gel coat application. 

With the testing program objective in mind, the AQMD worked with the Rule 1162 Testing 

Subgroup from July 2002 through June 2004 to develop the AQMD Test Protocol for 

Nonatomizing Spray Application Techniques for Gel Coats to be used for the Gel Coat Testing 

Program (Attachment A). The AQMD protocol incorporated key elements of the CFA Styrene 

Emissions Test Protocol & Facility Certification Procedures Revision 2.2 (March 1999), except 

for the following modifications: 

Test Facility - Temperature of the Working Area 

The CFA protocol states that the test chamber must be located in a temperature controlled 

environment. Previous CFA tests applied gel coat materials in a temperature controlled 

laboratory where the temperature ranged from 69 to 80 oF. The AQMD test applied gel coat in 

ambient temperatures, which ranged from 74 to 85 oF because that temperature range is 

representative of the conditions in the work areas for composite fabricators operating in the 

AQMD. 

Test Enclosure 

The cross sectional area of the spray booth doorway was reduced using 12 mil thick clear plastic 

in order to meet U.S. EPA Test Method 204 requirements for a temporary permanent enclosure. 

The CFA test protocol specified the use of a second blower to maintain laminar air flow at the 

surface of the test mold, with the air velocity ranging from 50 to 100 feet per minute. Instead of 

using a second blower, the AQMD Gel Coat Testing Program used a baffle which was placed in 

front of the mold, as an alternative procedure to divert the air flow to maintain the specified 

range of air velocity at the surface of the test mold. (for a detailed description regarding the test 

spray booth dimensions and modifications, and laminar flow air measurements, please see 

Attachment A). 

Test Mold Configuration and Size 

The testing mold was similar in dimensions and configuration to the CFA test mold (for more 

detailed information concerning the test mold and the air flow over its surface, please see 

Attachment A). 
Final Staff Report 

Proposed Amended Rule 1162 6 July 2005 

Gel Coat (Liquid) Tip Pressure Measurement 

The CFA test protocol does not specify the measurement of application pressure (pump or gun 

tip). The CFA test report contains pump pressure measurements (exit pump pressure equals 

pump gauge pressure multiplied by pressure ratio). The composite industry expressed concern 

regarding the use of pump pressure in developing a definition for the nonatomizing spray 

application technique for gel coats. Their concern included length of the hose and pump ratios 

and how they can differ between composite manufacturing facilities. Staff believed that the 

pressure at the tip of the gun, as applied, would be a valid method to define nonatomizing spray 

application technique for gel coats. Staff conducted field studies to compare the exit pump and 

tip pressure measurements. These studies indicated that while changes in the spray hose length 

and diameter changed the exit pump pressure, they showed no impact on the tip pressure of the 

gel coat spraying application equipment. The spray gun tip pressure represents a more accurate 

measurement of the pressure at which the gel coat material is applied and that same pressure can 

be compared to a regulatory standard for compliance determination. Accordingly, staff chose to 

implement the tip pressure measurement in the AQMD Gel Coat Testing Program. 

To implement the tip pressure measurements as required under the Gel Coat Testing Program, all 

spray guns tested were modified to include an adaptor installed before the tip of the gun to attach 

a liquid pressure gauge. The adaptor and the gauge were used only during the tip pressure 

measurements immediately prior to spraying/testing. The pressure gauges were precision, 

compact liquid pressure measurement units, and were calibrated according to the National 

Institute of Standard and Testing (NIST) standards.

Gel Coat Application Temperature 

The composite industry in the AQMD typically operates at ambient outdoor temperatures; most 

facilities are not well insulated and are not air conditioned. To address the diurnal temperature 

changes throughout the year, most operators are heating their gel coat materials to maintain more 

consistent spray applications. Field surveys conducted by the AQMD during August and 

September 2002 determined that applying heat to gel coat materials reduces viscosity, minimize 

porosity, enhance materials coverage/wetting and improve adhesion to the substrate. The Gel 

Coat Testing Program protocol requires that the application temperature of the gel coat material 

be maintained between 80 and 90oF, which were higher than the CFA/CMTI gel coat application 

temperature range of 69 to 80oF. 

VOC Emissions Measurement Equipment - Test Methods 

In addition to the U.S. EPA Test Method 25A, the AQMD Gel Coat Testing Program included 

additional, simultaneous VOC emissions sampling, as per SCAQMD Test Method 25.1. The 

AQMD protocol requires VOC emissions testing in triplicate. The average of the two test 

methods results are represented in this report. 

Some gel coat materials contained both styrene and methyl methacrylate. During the 

spraying/testing of these gel coats, additional gas samples were collected into evacuated canisters 

and were analyzed for both styrene and methyl methacrylate using U.S. EPA Test Method 18. 
Final Staff Report 

Proposed Amended Rule 1162 7 July 2005 

Gel Coat Film Samples and Analyses 

The CFA protocol did not include a requirement for qualitative or quantitative analyses for 

surface quality. The AQMD protocol required duplicate samples to be collected simultaneously 

with the VOC emissions testing. A discussion of the sampling procedure, sample recovery and 

surface quality analyses can be found under the Surface Quality Testing Methods section of the 

AQMD Gel Coat Testing Program. (Attachment A) 

Pre-Test Spray Pressure Adjustments and Setting 

Spray equipment manufacturers were directed to operate their equipment and apply gel coats at 

the lowest operating pressure settings, they believed was necessary to achieve an acceptable 

surface quality required by the composite industry. Prior to each nonatomizing gel coat spray 

test, AQMD staff observed the pre-test spray pressure adjustments conducted by each spray gun 

manufacturer to determine the minimum gel coat spray pressure to achieve the surface quality 

required by the composite industry. Each spray equipment operator commenced spraying gel 

coat at low pressure which produced a narrow spray pattern and surface with often accompanied 

gel coat sagging or streaming down the test surface. A sag or running is an indication that the 

application pressure is too low and that too much gel coat is applied at one point on the surface, 

resulting in an uneven surface that would not be acceptable to an end-user. The gel coated 

surface is the surface of the finished product that is seen, such as the top coat on a painted 

automobile. Paint running down the side of the car would be unacceptable. The operator would 

then gradually increase the spray pressure to the minimum pressure setting that would achieve a 

spray surface that had a uniform coverage of gel coat at the thickness that would be acceptable to 

the end user. In summary, the pre-test spray pressure adjustment determined the minimum 

nonatomizing spray pressure below which the gel coat surface quality will be unacceptable to the 

end-user. 

The average nonatomizing spray pressures used in the AQMD Gel Coat Testing Program was 

higher when compared to the nonatomizing spray gel coat pressures used in the CFA/CMTI tests 

to develop the Unified Emission Factor for gel coats (UEF 2001). This was unexpected since the 

gun manufacturers have stated that they have made improvements to their nonatomizing spray 

equipment since 2001. The CFA/CMTI and the AQMD tests measured the nonatomizing gel 

coat spray pressure at the exit of the pump and the tip of the spray gun, respectively. Based on 

AQMD field observations, the exit pump spray pressures of the CFA/CMTI tests were converted 

to spray tip pressures using the following equation: Estimated Spray Tip Pressure = Exit Pump 

Pressure x 0.65. The average measured pressure at the tip of the spray gun was 440 pounds per 

square inch where the calculated tip pressure for the CFA tests was 417 pounds per square inch. 

AQMD Gel Coat Testing Program Results

As previously stated, the AQMD collected VOC emissions and gel coat film samples from 

August through October 2004 (Attachment A). Table 1 is a comparison of the VOC data 

collected, stated as an emission rate, and the emission rate that the UEF (2001) table would 

predict for the same gel coats that were tested by the AQMD. The AQMD emission rates listed 

summarize the emissions data for the four spray equipment manufacturers that sprayed four 

different gel coats using air-assisted airless and nonatomized spray equipment. The average 

measured pressure at the tip of the spray gun during the AQMD tests was 440 pounds per square 
Final Staff Report 

Proposed Amended Rule 1162 8 July 2005 

inch whereas the calculated tip pressure for UEF data was 417 pounds per square inch. Surface 

quality testing, as part of the testing program, demonstrated that there was no measurable 

difference when using air-assisted airless and nonatomized spray equipment. 

Table 1 shows that there were no discernable differences between the VOC emission rates of the 

air-assisted airless and nonatomizing applications when the nonatomizing is used at an 

application pressure high enough to achieve an acceptable surface quality. 

The AQMD Gel Coat Testing Program also included the collection and analysis of cured spray 

gel coat film samples. The samples were sent to California Polytechnic State University, San 

Luis Obispo for analysis. Surface quality analysis included porosity and water resistance tests 

(using ANSI Z124), orange peel test (using Distinctness of Image (DOI) orange peel panels), and 

Gloss (using ASTM D523). Surface quality analysis showed no significant differences between 

the air-assisted airless and nonatomizing applications (for more detailed information, please see 

Attachment A). 

The data collected through the Gel Coat Testing Program demonstrates that it was 

technologically infeasible to apply gel coat materials with nonatomizing spray application 

equipment at pressures needed to achieve the UEF emission factors at the industry surface 

quality requirements. 

Table 1 

VOC Emission Rates Comparing Unified Emission Factors (UEF) and AQMD Testing 

Program for Gel Coat Air-Assisted Airless and Nonatomized Applications 

VOC Emissions lb/Ton 

(Pounds of VOC per Ton of Sprayed Gel Coat) 

Gel Coat Atomized Application Nonatomized Application

Monomer 

Content 

% 

UEF AQMD UEF AQMD 

Clear 40.9 460 438 268 457 

San Bright White 30.8 274 373 177 306 

Midnight Blue 32.9 293 233 196 209 

Sandable Gray 27.3 243 223 145 207 
Final Staff Report 

Proposed Amended Rule 1162 9 July 2005 

Granite-Filled Clear Gel Coat Spray 

During the development of PAR 1162, composite facilities which spray granite-filled clear gel 

coat to create granite-like surface expressed concerns about the feasibility to comply with the 

nonatomizing spray application technique requirements of Rule 1162. The larger diameter of the 

granite material in the clear coat could not pass through the smaller diameter of the nonatomizing 

spray gun nozzles. Staff observed field tests where granite-filled clear gel coat was sprayed by a 

local spray equipment manufacturer using high-volume, low-pressure (HVLP) spray equipment 

at an air pressure less than 10 psi. HVLP is a compliant application technique listed in PAR 

1162. 

EMISSONS INVENTORY AND EMISSIONS FOREGONE 

Prior to November 17, 2001 Rule 1162 amendment, composite fabricators applied gel coats 

using atomized spray applications such as air-assisted airless and high-volume, low pressure 

spray application equipment. The Rule 1162 amendment in 2001 required fabricators to use the 

nonatomizing spray application technique for gel coats and resins. The VOC emissions 

reduction associated with the nonatomizing spray application technique of gel coats was 

calculated based on the difference between the emission rates for the atomized and nonatomized 

spray application equipment listed in the UEF table (2001). 

Current PAR 1162 deletes the requirement of nonatomizing application of gel coats. Therefore, 

the VOC emissions reduction associated with the nonatomizing spray application of gel coats (as 

part of November 17, 2001 Rule 1162 amendment) are now VOC emissions foregone. 

Emissions Inventory of the Nonatomizing Spray Application of Gel Coats 

The emissions inventory/foregone associated with the nonatomizing spray application of gel 

coats are calculated based on the following: 

• The emissions inventory of gel coats is based on the 1998-99 emissions inventory 

of composite operations in the AQMD. That inventory reflects a usage of 2,206.1 

tons per year of gel coats. 

• The emissions inventory of gel coats includes clear and pigmented gel coats. Clear 

gel coats include marble clear gel coats and other clear gel coats. Pigmented gel 

coats include white and off-white gel coats and non- white gel coats. 

• The emissions inventory of gel coats is based on compliance with the July 1, 2003, 

monomer content requirements for gel coats as follows: marble clear gel coats 

(40%), other clear gel coats (44%), white and off-white gel coats (30%), and 

nonwhite gel coats (37%). It also based on the atomized application of gel coats. 

• Clear and pigmented gel coats represent 15% and 85%, respectively, of the total gel 

coats usage in composite operations in the AQMD during 1998-99. 

• White/off-white, and non-white represent 85% and 15%, respectively, of the total 

pigmented gel coats usage in composite operations in the AQMD during 1998-99. 

• Marble clear gel coats and other clear gel coats represent 35%, and 65%, 

respectively, of the total clear gel coats usage in the AQMD during 1998-99. 
Final Staff Report 

Proposed Amended Rule 1162 10 July 2005 

• The emissions reduction of the nonatomizing application for marble clear gel coats, 

other clear gel coats, white and off-white pigmented gel coats, and non-white 

pigmented gel coats are calculated using the 2001 UEF (see Attachment B). 

• The nonatomizing emissions reduction of gel coats is calculated using the gel coat 

emissions inventory and the emissions reduction efficiency for the nonatomizing 

application of gel coats. 

(1) Emissions Inventory From Gel Coats

Table 2 lists the VOC emissions from gel coats based on the current Rule 1162 monomer 

content, and subcategories of gel coat materials after July 1, 2003, without the use of 

nonatomizing application technologies. 

Table 2 

VOC Emissions Inventory of Gel Coats Based on July 1, 2003 

 Monomer Content and without Nonatomizing Applications

Specific 

Type of Gel 

Coat, & SubCategory 

Allowed 

Monomer 

Percentage in 

Current Rule 

after 

July 1, 2003

(%)

Unified Emission 

Factor a

(in pounds of styrene 

per tons of gel coat)

Units 

Adjustment 

Factor 

(1 ton = 2000 

pounds)

Estimated 

Annual Total 

Gel Coat 

Usage

(in tons per year)

Percentage of 

Estimated Annual 

Total Gel Coat 

Usage per Type & 

Sub-Category 

Projected VOC 

Emissions From

Gel Coats 

(in tons per year)

Clear, for 

marble 

resins 

40 (439 ÷ 2000) x 2206.10 x 0.15 x 0.35 = 25.42 

Clear, for 

other resins 44 (522 ÷ 2000) x 2206.10 x 0.15 x 0.65 = 56.14 

Pigmented, 

White and 

Off White 

30 (267 ÷ 2000) x 2206.10 x 0.85 x 0.85 = 212.79 

Pigmented, 

Non-White 37 (377 ÷ 2000) x 2206.10 x 0.85 x 0.15 = 53.02 

 a) UEFs for Open Molding of Composites, July 23, 2001 (see Attachment B) TOTAL 347.37 

(2) Efficiency of Nonatomizing Application of Gel Coats

The efficiency of gel coats nonatomizing applications are calculated using the (E atm) the 

emissions of atomizing application and the (E non.), emissions of nonatomizing 

application, for each gel coat as follows: 

Efficiency of Nonatomizing Application = (E atm. – E non. /E atm.) x 100 

(A) Clear Gel Coats: 

 (I) Marble Resins (40% monomer content) 

 (439-259/439) x 100 = 41% 
Final Staff Report 

Proposed Amended Rule 1162 11 July 2005 

 (II) Other Resins (44% monomer content) 

 (522-296/522) x 100 = 43.30% 

(B) Pigmented Gel Coats: 

 (I) White and Off-white (30% monomer content)

 (267-169.36/267) x 100 = 36.57% 

 (II) Non-white (37 % monomer content)

 (377-232/377) x 100 = 38.46% 

The emissions reductions of the nonatomizing application of gel coats are calculated using the 

emissions inventory and nonatomizing application efficiency of each gel coat. Table 3 illustrates 

the emissions inventory and reduction of gel coats.

Table 3 

VOC Emissions Inventory and Emission Reductions from Gel Coats 

Gel Coat /Monomer Content 

Atomizing 

Emissions 

Inventory 

(tpy) 

% of Nonatomizing 

application 

Efficiency 

Nonatomizing 

Emission 

Reductions 

(tpy) 

Marble Gel Coats/40% 25.42 41.00 10.42 

Other Gel Coats/44% 56.14 43.30 24.31 

White and Off-White Gel Coats/30% 212.79 36.57 77.82 

Non-White Gel Coats/37% 53.02 38.46 20.39 

Total 347.37 132.94 

The VOC emissions inventory associated with the nonatomizing spray application technique of 

gel coat is 132.94 tpy or 0.43 tpd. Therefore, the emissions reductions foregone due to the 

deletion of the requirement of the nonatomizing spray application technique of gel coat is 0.43 

tpd. 

Emissions Foregone Resulting from Proposed Exemption 

Calculation of the Emission Rate of the Air Spray Application 

The UEF (2001) table does not specifically list gel coat emission rates for air spray equipment. 

Additionally, staff has not identified any other source of published emission rates for gel coat 

using air spray equipment. However, the emission rate for the air spray application can be 

calculated using the emission rates of the air-assisted airless spray, referred to “gel coat 

application” in the UEF (2001) table, the transfer efficiency of both the air spray and air-assisted 

airless spray applications and the following assumptions and analysis: 

• Each composite part requires one gallon of gel coat. 
Final Staff Report 

Proposed Amended Rule 1162 12 July 2005 

• 100 gallons of gel coat sprayed using air air-assisted airless application (40% 

transfer efficiency) to produce 40 composite parts.

• 100 gallons of the same gel coat sprayed using an air spray gun (24% transfer 

efficiency) on the same composite parts will produce 24 parts. 

• To complete the spraying of the other 16 parts (40 -24) using an air spray gun, the 

operator needs to increase his usage of gel coat materials. 

• The amount of gel coat materials required to spray the 40 parts using air spray is 

calculated to be 166.7 gallons (100 gallons x 40/ 24). 

• The amount of gel coat materials required to produce 40 composite parts using air 

spray and air-assisted airless spray applications are 166.7 and 100 gallons, 

respectively. 

• The VOC emission of both air spray and air-assisted airless spray applications is 

proportional to the gel coat materials usage 

Therefore the relationship between the emission rate of the air-assisted airless spray (E1) and 

the emission rate of the air spray application (E 2) can be illustrated as follows: 

E2 = E1 x 1.67 

where: 

 E1 = The air-assisted airless emission rate of the UEF table(2001), in 

 pounds of VOC per pound of gel coat sprayed using the gel 

 application 

 E2 = The spray emission rate, in pounds of VOC per pound of gel coat 

 sprayed 

The emission rates using air-assisted airless spray (E1) and air spray (E2) application equipment 

for pin striping/multi color gel coat (37% monomer content) are 0.1885 and 0.3148 pounds of 

VOC per pound of sprayed gel coat materials. 

Emissions Foregone Due to Pin Striping Exemption 

Pin striping is a spray application technique used to apply one or more narrow bands, marks or 

streaks of gel coats onto the surface of boats, amusement park structures and other composite 

products for decorative or identification purposes. The gel coat used for pin striping may be 

different in color or texture than the surrounding areas of the composite product. 

 

In the pin stripe spray application procedure, the operator will mask off a specific area to define 

the bands, marks or streaks dimensions on the spray mold of the composite product. After the 

application of the striping gel coat(s), the operator will continue the build up of the composite 

products (spray gel coat, resin and fiberglass). 
Final Staff Report 

Proposed Amended Rule 1162 13 July 2005 

The proposed pin striping exemption allows pin striping gel coat spray onto pleasure watercraft, 

amusement park fixtures and structures, using cup-guns or other air spray application equipment. 

• Affected sources include twenty facilities (seven boat manufacturers, three 

amusement parks, and ten additional pin striping facilities staff has identified based 

on the potential future need to conduct pin striping spraying within the composite 

industry universe in the AQMD). 

• Exemption limited to one gallon of gel coat per day per facility. 

• A hand-held cup gun provides the best performance for pin striping or thin line 

application, minimizes the amount of solvent needed for clean up whenever a change 

in color is needed (as compared to air-assisted airless spray gun or any other spray 

application listed in PAR 1162. 

The calculation of VOC emissions foregone resulting from the limited usage exemption of pin 

striping to the requirement of lower emitting gel coat application technology is summarized in 

Table 5. 

Table 5 

VOC Emissions Foregone Due to the Exemption 

Air Spray Versus Air-Assisted Airless Spray 

Pin Striping 

Category Existing 

Source 

Potential 

Sources 

Gel Coat Pigmented Pigmented 

Monomer Content Percent 37 37 

Exemption, Gallons per Day per Facility 1 1 

Average Pounds per Gallon 10.65 10.65 

Exemption, Pounds per Day Per Facility 10.65 10.65 

Difference in Emission Rate (E1-E2) 0.1263 0.3148 

Number of Affected Sources 10 10 

Emission Foregone, Pounds per Day 13.45 33.53 

The total VOC Emissions Foregone due to the Proposed Exemption = 46.98 pounds per day or 

0.02 ton per day. 

Therefore, the proposed amendments, including the deletion of the requirement of nonatomizing 

spray application of gel coat and the pin striping exemption will result in VOC emissions 

reductions foregone of 0.45 tpd. 
Final Staff Report 

Proposed Amended Rule 1162 14 July 2005 

COST IMPACTS 

There will be no cost impacts associated with the proposed amendment because the existing 

equipment can be used by the industry.

ENVIRONMENTAL ASSESSMENT 

The proposed project consists of two parts: rescinding the nonatomized gel coat 

application technique requirement and introducing an exemption for gel coat pin striping 

operations. The AQMD was the lead agency and prepared a Final Supplemental 

Environmental Assessment (SEA) and Final EA for the July 8, 2005 modifications to Rue 

1162. The Final SEA and Final EA were prepared pursuant to CEQA Guidelines §15252 

and the AQMD’s certified regulatory program (AQMD Rule 110). The purpose of the 

Final SEA and Final EA was to describe the proposed project and to identify, analyze, 

and evaluate any potentially significant adverse environmental impacts that could have 

resulted from adopting and implementing the proposed amendments to Rule 1162. 

The Draft SEA (SCAQMD No. 050316JK, dated March 16, 2005) was prepared for 

rescinding the nonatomized gel coat application technique requirement because this 

proposal was considered to be a modification of a previously approved project. The 

Draft EA was circulated to the public for a 45-day review and comment period from 

March 17, 2005 to May 3, 2005. The only environmental topic where significant adverse 

impacts were identified was air quality. Rescinding the nonatomizing gel coat 

application technique requirement would permanently forego the previously expected 

853 pounds of styrene emission reductions per day, which exceeds the AQMD VOC 

significance threshold of 55 pounds per day. In addition, acute and chronic 

noncarcinogenic risk associated with styrene emissions would exceed the AQMD’s 

hazard index significance threshold of 1.0. Therefore, rescinding the nonatomized gel 

coat application technique is significant for air quality. Minor modifications have been 

made to the Draft SEA such that it is now a Final EA. 

A Draft EA (SCAQMD No. 050504JK, dated May 4, 2005) was prepared for the 

proposed gel coat pin striping exemption because this modification was outside of the 

scope of impacts analyzed in the Draft SEA. The Draft EA was circulated to the public 

for a 30-day review and comment period from May 5, 2005 to June 3, 2005. No 

environmental topics were significantly adversely affected by the exemption. The 

analysis concluded that the gel coat pin striping exemption could result in an increase in 

total VOC emissions by as much as 46.9 pounds per day, which is below the AQMD 

VOC significance threshold of 55 pounds per day. The chronic and acute hazard indices 

were estimated to be below 1.0, which is the AQMD significance threshold for 

noncarcinogenic risk. Therefore, the exemption would not substantially increase the 

severity of the air quality impact or change any of the conclusions in the Final SEA. 
Final Staff Report 

Proposed Amended Rule 1162 15 July 2005 

Although evaluated in a separate CEQA document, modifying the project to include the 

gel coat pin striping exemption would not add a new significant environmental impact, 

substantially increase the severity of an environmental impact, nor alter the conclusions 

relative to the Draft SEA. Because of the focused nature of the proposed project 

evaluated in the Draft SEA, a second CEQA document (Draft EA) was prepared to allow 

the public and public agency decision-makers an opportunity to review and comment on 

the gel coat pin striping exemption. The AQMD did not receive any comments on either 

the Draft SEA or Draft EA during the public review and comment periods. Copies of the 

EA’s have been included as an attachment to this report. 

SOCIOECONOMIC ANALYSIS 

The proposed amendment to Rule 1162 deletes the requirement of the nonatomizing spray 

application of gel coats, which results in no additional costs to the affected sources because the 

existing equipment can continue to be used. Therefore, there is no socioeconomic impact 

analysis has been prepared. 

COMPARATIVE ANALYSIS 

As required by Health and Safety Code Section 40727.2, the purpose of this analysis is to 

identify and analyze any federal or other AQMD rules that apply to the same equipment or 

source type as the proposed amendments. In addition to PAR 1162, the composite operations in 

the AQMD are also subject to Rule 1132 and the National Emission Standards for Hazardous Air 

Pollutants (NESHAP) for Reinforced Plastic Composites Production (40CFR63, Subpart 

WWWW) and for Boat Manufacturing (40 CFR Part 63, Subpart VVVV). A comparative 

analysis of these requirements with the proposed amendments is summarized in Table 6. 

CONCLUSIONS AND RECOMMENDATIONS 

Staff has determined that there are no significant differences between the VOC emission rates of 

the air-assisted airless and nonatomizing applications when the nonatomizing is used at a 

pressure high enough to achieve an acceptable surface quality. Therefore, it is staff’s 

recommendation that Rule 1162 be amended to delete the requirement of the nonatomizing spray 

application technique of gel coat. In addition, staff proposes to add language to clarify that a 

hand-held spray gun can be used for touch-up and repair for gel coat and resin applications. 

Finally, a small use exemption has been added for pin striping gel coat. 
Final Staff Report 

Proposed Amended Rule 1162 16 

Table 6 

Comparison Analysis of PAR 1162, Rule 1132 and 40 CFR Part 63 Subparts VVVV and WWWW 

PAR 1162 RULE 1132 40 CFR PART 63 

Subpart VVVV 

40 

Sub

Objective

Controls VOC and HAP emissions. Further controls of VOC and HAP 

emissions beyond Rule 1162. 

Controls HAP emissions. Controls HA

Applicability

Applies to all composite operations. Applies to composite facilities, 

which emit > 20 tpy of VOCs and 

utilize paint spray booth(s) in their operations. 

Applies to boat manufacturing composite facilities, which represent major source of HAPs. 

Applies to threinforced aplastic compintermediate 

Compliance Options

-Pollution Prevention Technologies 

-Add-on Control 

-Pollution Prevention Technologies 

 -Add-on control  -Combination between Pollution 

Prevention Technologies and Addon Controls. 

-Compliant materials -Add-on Control -Point Value Averaging 

-HAP limits sources < 10- 95 % contr≤100 tpy -Allows aveemissions li

Compliance Effective Dates

-July 1, 2002: Nonatomizing applications of resins and lower monomer content of gel coats July 1, 2003: Lower monomer content of gel coats and resins 

-January 1, 2002: Nonatomizing application of resins (gel coats excluded) and lower monomer contents of gel coats. -July 1, 2004: Reduction of VOC emissions by 65 % of Rule 1162 limits in effect as of January 19, 2001. 

-August 22, 2001: New facilities must comply with the regulation requirements. -August 22, 2004: Existing facilities must comply with the regulation requirements 

- April 21, 2source - April 21, 2source (consAugust 2, 20- Upon Start source (consApril 21, 20- After three Existing aremajor sourc- Upon the csource beco

Equipment Requirement

Requires nonatomizing technologies for resin applications. 

Requires nonatomizing application technologies only for resins. 

Allows atomizing and nonatomizing applications. 

Allows atomnonatomizin
Final Staff Report 

Proposed Amended Rule 1162 17 

Table 6 

Comparison Analysis of PAR 1162, Rule 1132 and 40 CFR Part 63 Subparts VVVV and WWWW 

(Cont’d) 

PAR 1162 RULE 1132 40 CFR PART 63 

Subpart VVVV

40 

Su

Monomer Content by weight 

Clear Gel Coat -For Marble Resin 40 % (VOC)

-Other resins 44 % “Pigmented Gel Coats -White and off-white 30 % “ -Non-white 37 % “ General Purpose Resins -Marble Resins 10 % “ -Tub/Shower Resin 20 % “ -Lamination Resins 35 % “ -Others 35 % “ Specialty Resins -Fire Retardant 38 % “ -Corrosion Resist. 48 % “ -High Strength 40 % “ 

44 % (VOC)

 N/A  N/A  30 % “  37 % “ 

 35 % “  N/A  N/A  N/A  N/A  42 % “  48 % “  48 % “ 

48 % (MHC)* 

 N/A  N/A  33 % “  40 % “  35 % “  N/A  N/A  N/A  N/A  N/A  39 % “  N/A 

(MHC)*: Maximum HAP Content 

4

(MHC)*: M

Fillers

Offers fillers as an option to comply with the monomer content requirement of the applicable resins. 

 N/A N/A 

Vapor Suppressants

Requires that tub/shower resins to be vapor suppressed. 

 N/A N/A Table 3 inclu

calculate the vapor suppre

Closed Molding System

Requires < 4 % weight loss of 

polyester resins during polymerization 

 N/A N/A 

Pultrusion Operation

Requires < 3 % weight loss of 

polyester resins during polymerization 

 N/A N/A Reduce total 

lease 60% by 
Final Staff Report 

Proposed Amended Rule 1162 18 July 2005 

DRAFT FINDINGS 

Before adopting, amending or repealing a rule, the AQMD shall make findings of necessity, 

authority, clarity, consistency, non-duplication, and reference, as defined in Health and Safety 

Code Section 40727. The draft findings are as follows: 

Authority - The AQMD Governing Board obtains its authority to adopt, amend or repeal rules 

and regulations from Health and Safety Code §§40000, 40001, and 40440. 

Clarity - The AQMD Governing Board finds and determines that Proposed Amended Rule 1162 

is written and displayed so that the meaning can be easily understood by persons directly 

affected by it. 

Consistency – The AQMD Governing Board finds and determines that Proposed Amended Rule 

1162 is in harmony with, and not in conflict with or contradictory to, existing statutes, court 

decisions, or federal or state regulations. 

Non-Duplication – The AQMD Governing Board has determined that Proposed Amended Rule 

1162 does not impose the same requirements as any existing state or federal regulation, and the 

extent they overlap with NESHAP requirements are necessary to carry out the duty to adopt rules 

implementing the AQMP. 

Reference - In adopting these proposed amendments, the AQMD Governing Board references 

the following statutes which AQMD hereby implements, interprets or makes specific: Health and 

Safety Code Sections 40001 and 40440. 

Necessity - The AQMD Governing Board find and determines that it is necessary to amend Rule 

1162 to delete the requirement for nonatomizing spray application of gel coats which has been 

shown to be infeasible. 

COMMENTS AND RESPONSES 

The following comments were received during the rule development process, including the 

public workshop held on April 12, 2005. 

Comment 1 

Based on the AQMD Gel Coat Test findings, can the industry continue to use the gel coat 

nonatomizing emission rates in the UEF (2001) table to calculate the gel coat emissions 

inventory of composite facilities? 

Response 1 

The AQMD Gel Coat Test Program results demonstrated that the four spray equipment operators 

could not operate at pressures equal to or less than those pressures used to develop the UEF 

nonatomized emission factors for gel coat and achieve an acceptable surface quality. In fact, the 

results showed no significant difference between the emission rates of the nonatomized and 

conventional spray applications of gel coats. As a result, the gel coat nonatomized emission 
Final Staff Report 

Proposed Amended Rule 1162 19 July 2005 

rates of the UEF (2001) table can not be used to calculate emissions for composite facilities in 

the AQMD. 

Comment 2 

The definition of the “air-assisted airless spray” and the “electrostatic application” should be 

consistent with those definitions listed in both Rule 1107 and Rule 1136. 

Response 2 

Neither Rule 1107 nor Rule 1136 defines air-assisted airless spray in the rule. The definition of 

the electrostatic application in PAR 1162 is consistent with the same definition in both Rules 

1107 and 1136. 

Comment 3 

GRACO has conducted several studies concerning the application of gel coat using the 

electrostatic application technique. The results of these studies were published in the Composite 

Manufactures Association (CFA) journal (copy of the publication was submitted to staff for 

review). 

Response 3 

The proposed amended rule includes a requirement to apply gel coat with lower emissions 

application technology, which includes electrostatic application. Staff will continue to assess the 

feasibility of the electrostatic application of gel coat. 

Comment 4 

Attempting to reduce the VOC emission through changes in the chemical composition of gel coat 

materials, such as through the use of vinyl toluene, will require a great deal of testing to assure 

the integrity of the composite products. Such tests are beyond the scope of the gel coat surface 

quality tests included in the AQMD test program and may include chemical and mechanical 

resistance tests, thermal shock tests as well as other tests. 

Response 4 

Neither Rule 1162 nor the proposed amendment advocates a specific chemistry for gel coats. 

Therefore, testing for different formulations was not within the objectives of the AQMD Gel 

Coat Testing Program. Staff is soliciting suggestions to mitigate the VOC emissions reduction 

foregone from gel coat applications resulting from the proposed amendments. Reducing the 

VOC monomer content of gel coats may be one way to mitigate the emissions foregone. 

Staff would like to emphasize that the objective of AQMD Gel Coat Testing Program was to 

determine the minimum range of pressure values at the tip of the nonatomizing spray gun that 

produces gel coat sprayed products with surface quality that is no less than the surface quality 

achieved when using an atomizing spray gun in accordance with the composite industry 

standards and achieves the emissions rates stated in the UEF (2001) table for composite 

manufacturers operating in the AQMD. The testing protocol required the use of the same gel 

coat in each gel coat category to determine the operating pressures of each of the four different 

nonatomizing and the air-assisted airless spray guns. The gel coat formulation was not part of 

the testing program. Furthermore, the surface quality tests performed in the test program 

including porosity, gloss, orange peel and water resistance were specifically used to compare the 
Final Staff Report 

Proposed Amended Rule 1162 20 July 2005 

surface quality of the nonatomizing and the air-assisted airless spray applications and not to 

determine the performance of the gel coat materials used in the test program. 

Comment 5 

The manufacture of high quality molds is critical to manufacture of composite products. Any 

defect or substandard surface quality of a mold will produce the same defect on the surface of all 

composite parts produced by that mold. Additionally, the amount of tooling gel coat to produce 

molds manufactured in the AQMD represents approximately 1 to 1.5 percent of the total usage of 

gel coat in the composite industry. Based on our experience, the atomized air spray gun is the 

only technology currently available to produce a mold of acceptable quality when using typical 

tooling gel coat. 

Response 5 

Staff acknowledges the importance of the surface quality of the mold for composite products 

manufacturing. The surface quality of the mold determines in large part the surface quality of 

the finished composite product. The manufacture of molds is a sophisticated fabrication process, 

which is currently limited to two major composite operations in the AQMD. 

One facility, one of the largest mold manufacturing facilities in the nation, builds molds for 

different composite manufacturers. Staff contacted the company and verified that they apply a 

specific gel tooling gel coat formulation using high-volume, low-pressure spray application 

equipment. This is one of the compliant application techniques in the rule. 

The second facility is a large fabricator of bathware products. This facility has developed the 

expertise to build molds for their own composite products. This facility informed staff that they 

use the standard compliant tooling gel coat and have determined that they must use an air 

atomized spray gun to obtain the surface quality necessary for the mold. Staff has verified that 

this facility has submitted an application for a Permit to Construct and Operate an air pollution 

control system (concentrator/afterburner) to comply with the requirements of Rule 1162 and 

other rules. 

Therefore, no amendment is necessary or proposed since alternative compliance techniques are 

available. 

Comment 6 

Pin striping is used to apply small amount of different pigmented gel coat on boats and structures 

in amusement parks for decorative or identification purposes. Current practice is to use an air 

spray gun with a small cup (less than a quart) container attached to the base of the air spray gun. 

It is not technologically feasible to use an airless, air-assisted airless, or other lower emitting 

application technology that uses a larger container (typically a 55 gallon drum) to apply pin 

striping. A hand-held cup gun also minimizes the amount of clean-up solvent needed to clean up 

the spray equipment (small cup container versus a length of supply hose) whenever a change in 

color is needed. 

Response 6 

Staff agrees that the amount of gel coat used specifically used in pin striping operations at any 

one facility is very small. In addition, the process of applying several pin stripes of different 

color gel coat using the spray cup gun will use less clean-up solvent as compared to the clean up 

of the air-assisted airless spray gun or any other spray applications listed in the PAR 1162. Staff 
Final Staff Report 

Proposed Amended Rule 1162 21 July 2005 

has proposed an exemption from the spray application requirement of PAR 1162 for pin striping 

applications provided that the total usage of gel coat does not exceed one (1) gallon per day per 

facility. 

REFERENCES 

South Coast Air Quality Management District, “Draft Final AQMD Gel Coat Testing Program 

Report” February 2005. 

South Coast Air Quality Management District, “Final Staff Report For Proposed Amended Rule 

1162-Polyester Resin Operations,” July 9, 2004. 

South Coast Air Quality Management District, “Final Staff Report For Proposed Amended Rule 

1162-Polyester Resin Operations,” July 11, 2003. 

South Coast Air Quality Management District, “Final Staff Report For Proposed Amended Rule 

1162-Polyester Resin Operations,” November 9, 2001.

R.A. Haberlein, “Technical Discussion of the United Emission Factors for Open Molding 

Composite,” Engineering Environmental, July 17, 2001.