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OAR Box 1500 

Prepped by Ollie Stewart 

Document Number: 

59) ll-C-85 

Docket Number: 

A-94-52 

Printed 8/5/2008 1:51:29 PM Sheet 59 of 343 
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>«0ST<% A 94 52 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY | | - £ - §S 

I ^T7 7 ? RESEARCH TRIANGLE PARK. NC 27711 

DEC 3 0 897 

OFFICE OF 

AIR OUALITY PLANNING 

AND STANDARDS 

Mr. Stephen McNally 

Director of Government Affairs 

Composites Fabricators Association 

1655 North Fort Myer Drive, Suite 510 

Arlington, Virginia 22209 

This is in response to your letter of November 11,1997 regarding the incorporation of a 

controlled spray program in the maximum achievable control technology (MACT) standard for 

reinforced plastic composites manufacturing. After discussion with our staffs, we have concluded 

that the controlled spray program cannot be used as an. option to offset or reduce the MACT floor 

level of emissions control to be determined by your proposed averaging concept. The remainder 

of this letter provides the rationale for our conclusion, addresses several points raised in your 

letter, and presents a proposal for promoting the concept of better spraying practices in the 

standard. 

The controlled spray program was designed by industry to minimize spraying emissions by 

using better spray practices. It was presented as part ofthe averaging approach that you and 

other industry representatives proposed for determining the MACT floor and establishing 

compliance with the MACT standard. You proposed a 0.77 emission reduction factor be applied 

to the averaging approach for those facilities choosing to adopt a controlled spray program. This 

would offset one or more control options in the standard currently under consideration, such as 

material specifications on the resin, equipment specifications for the application technique, and/or 

abatement equipment. The reasons we concluded that the controlled spray program cannot be 

traded with the other options are that the program is considerably more difficult to enforce and 

cannot be assured to achieve quantifiable and continuous emission reductions. 

With regard to enforceability and continuous compliance, the program does not contain 

objective parameters which would allow a person to distinguish between a facility that is 

performing (that is, achieving the reductions associated with) controlled spraying and one that is 

not. For example, establishing the lowest pressure setting that provides an adequate fan pattern 

is subjective. Further, it is not only pressure setting that affects the fan pattern, but materials, tip 

size, catalyst ratio, and perhaps even other parameters that would make it difficult for 

enforcement personnel to objectively determine compliance with the MACT standard. The 

photographic images suggested in your letter would aid in the demonstration that the pressure 

setting procedure was carried out; however, they would not guarantee that the lowest pressure 

setting that provides an adequate fan pattern was found. Issues arise in other parts ofthe 

Internet Address (URL) • http://www.epa.gov 

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program as well, such as the verification of proper operator technique. A flange could well limit 

the spray on some molds, but for convex and complicated shapes, it would not guard against 

spraying past the mold perimeter. Imagine a hemisphere-shaped mold, for example. A flange on 

the edge ofthe mold will not guard against the operator spraying over the top or past the right or 

left side ofthe mold. Even with parts where the flange will serve as a guard, there is no 

procedure that assures continuous compliance, i.e., that the operator is always spraying within the 

flange distances. 

Your letter indicated that there was close agreement in the results ofthe controlled spray 

testing done by the Composites Fabricators Association (CFA) and the Research Triangle 

Institute (RTI) under cooperation with the Environmental Protection Agency (EPA). Our 

andysis ofthe results indicates that the agreement was not as stated in your letter. For the gel 

coat operation tested, RTI achieved a 9 percent reduction in emissions in terms of percent 

available styrene (%AS) for a high air velocity situation and a 17 percent reduction for a low air 

velocity situation, as compared to the CFA's result of 42 percent reduction in %AS emissions. 

For the resin operation, RTI achieved a 36 percent emission reduction of %AS emissions as 

compared to the CFA's result of 20 percent emission reduction in %AS emissions. These results 

are not in close agreement; however, they do indicate that spray technique influences the amount 

of emissions that result from polyester resin spray operations. This has been a longstanding point 

of agreement between the EPA .and industry representatives. 

The EPA recognizes controlled spraying as a best management pollution control practice. 

The operation of an emission source in a manner consistent with good .air pollution practice is 

required by Subpart A of Part 63 (which applies to all MACT standards). In particulw, under 

Section 63.6(e)(l)(i), "At all times, including periods of startup, shutdown, and malfunction, 

owners or operators shall operate and maintain any affected source, including associated air 

pollution control equipment, in a manner consistent with good air pollution control practices for 

minimizing emissions at least to the levels required by all relevant standards." To encourage 

sources to use controlled spraying techniques, we are considering inclusion of a requirement for 

an operator training program that addresses better spraying practices in the MACT standard. This 

requirement would be consistent with the provision of Section 63.6(e)(l)(i). A facility could 

demonstrate compliance by keeping records of its training program and records demonstrating 

that operators applying resin have taken this training. This concept was incorporated in Subpart 

JJ-National Emission Standards for Wood Furniture Manufacturing Operations. The training 

program (and other work practices) was required in addition to emission limitations, equipment 

standards, and material requirements. Your efforts on the controlled spray program would be 

valuable to facilities that choose to expand upon or develop new operator training programs to 

meet such a requirement, if established. 

In summary, we support encouraging better spray practices with the standard, but we do 

not plan to allow them to be used to offset the other emission reduction techniques that were used 

in detennining the level ofthe MACT standard. Due to the lack of enforceability ofthe program 

designed by the industry, it cannot be used to generate credits which would be traded with the 

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other emission reduction techniques to meet the MACT standard. Our current thinking is to add 

a requirement for operator training which would encourage better spray practices. We appreciate 

your efforts to develop a program to promote better spray practices and your ongoing work to 

make your members aware ofthe importance of operator technique on reducing emissions. 

Sincerely, 

Jruce Jordan 

Director 

Emission Standards Division 

T3 f^fSLAju^zJ 

JohnB. Rasnic 

Director 

Manufacturing, Energy, and 

Transportation Division 

Office of Compliance 

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