SB
Control Techniques Guidelines for
Fiberglass Boat Manufacturing Materials

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                                         EPA-453/R-08-004
                                           September 2008
    Control Techniques Guidelines for
Fiberglass Boat Manufacturing Materials
             U.S. Environmental Protection Agency
           Office of Air Quality Planning and Standards
             Sector Policies and Programs Division
                Research Triangle Park, NC
                                                   in

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                                                       IV

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                           TABLE OF CONTENTS

I.      Introduction	1
II.     Background and Overview 	2
III.    Applicability	3
IV.    Process Description and Sources of VOC Emissions	5
  A. Process Description 	5
  B. Sources of VOC Emissions 	7
V.     Available Controls and Existing Federal, State, and Local	
       Recommendations/Regulations 	8
  A. Available Control Options for Resin and Gel Coat	8
       1. Low VOC Resins and Gel Coats	8
       2. Vapor Suppressed Resins and Gel Coats	9
       3. Non-atomizing Resin Application	10
       4. Closed Molding	11
       5. Add-On Control  Systems	14
  B. Available Control Options for Mixing Containers	14
  C. Available Control Options for Cleaning Materials	14
  D. Existing Federal, State, and Local Recommendations/Regulations	15
       1. The 1990 National VOC Assessment	15
       2. The 2001NESHAP for Boat Manufacturing	15
       3. Existing State and Local VOC Requirements	17
VI. Recommended Control Options 	21
  A.   Recommended VOC Limits for Gel Coats and Resins	21
       1. Compliant Materials Option 	23
       2. Emissions Averaging Option	24
       3. Add-on Control Option	27
  B.   Recommended Option for Filled Resins	28
  C.   Work Practices for Resin and Gel Coat Mixing Containers	28
  D.   VOC Content and Vapor Pressure Limits for Cleaning Materials	29
VII. Cost Effectiveness of Recommended Control Options	29
VIII. References	31
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                                                       VI

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I.      Introduction

       Clean Air Act (CAA) section 172(c)(l) provides that state implementation plans
(SIPs) for nonattainment areas must include "reasonably available control measures"
(RACM), including "reasonably available control technology" (RACT), for sources of
emissions. Section 182(b)(2)(A) provides that for certain nonattainment areas, States
must revise their SIPs to include RACT for each category of volatile organic compound
(VOC) sources covered by a control techniques guidelines (CTG) document issued
between November 15, 1990 and the date of attainment.

       The United States Environmental Protection Agency (EPA) defines RACT as "the
lowest emission limitation that a particular source is capable of meeting by the
application of control technology that is reasonably available considering technological
and economic feasibility." 44 FR 53761 (September 17, 1979). In subsequent Federal
Register notices, EPA has addressed how States can meet the RACT requirements of the
Act.

       CAA section 183(e) directs EPA to list for regulation those categories of products
that account for at least 80 percent of the volatile organic compound (VOC) emissions,
on a reactivity-adjusted basis, from consumer and commercial products in areas that
violate the NAAQS for ozone (i.e., ozone nonattainment areas). EPA issued the list on
March 23, 1995, and has revised the list periodically. See 60 FR 15264 (March 23, 1995);
see also 71 FR 28320 (May 16, 2006), 70 FR 69759 (Nov. 17, 2005); 64 FR 13422
(March 18, 1999). Fiberglass boat manufacturing is included on the current section
183(e)list.

       This CTG is intended to provide State and local air pollution control authorities
information that should assist them in determining RACT for VOC from fiberglass boat
manufacturing operations. In developing this CTG, EPA evaluated the sources of VOC
emissions from the fiberglass boat manufacturing industry and the available control
approaches for addressing these emissions, including the costs of such approaches. Based
on available information and data, EPA provides recommendations for RACT for
fiberglass boat manufacturing.

       States can use the recommendations  in this CTG to inform their own
determination as to what constitutes RACT for VOC for fiberglass boat manufacturing in
their particular nonattainment areas. The information contained in this document is
provided only as guidance. This guidance does not change, or substitute for, requirements
specified in applicable sections of the CAA  or EPA's regulations; nor is it a regulation
itself. This document does not impose any legally binding requirements on any entity. It
provides only recommendations for State and local air pollution control agencies to
consider in determining RACT. State and local pollution control agencies are free to
implement other technically-sound approaches that are consistent with the CAA and
EPA's implementing regulations.

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       The recommendations contained in this CTG are based on data and information
currently available to EPA. These general recommendations may not apply to a particular
situation based upon the circumstances of a specific source. Regardless of whether a State
chooses to implement the recommendations contained herein through State rules, or to
issue State rules that adopt different approaches for RACT for VOC from fiberglass boat
manufacturing operations, States must submit their RACT rules to EPA for review and
approval as part of the SIP process. EPA will evaluate the rules and determine, through
notice and comment rulemaking in the SIP approval process, whether the submitted rules
meet the RACT requirements of the CAA and EPA's regulations. To the extent a State
adopts any of the recommendations in this guidance into its State RACT rules, interested
parties can raise questions and objections about the substance of this guidance and the
appropriateness of the application of this guidance to a particular situation during the
development of the State rules and EPA's SIP approval process.

       CAA section 182(b)(2) requires that a CTG issued after November 15, 1990 and
the date of attainment include the date by which States subject to section 182(b) must
submit SIP revisions in response to the CTG. Accordingly, EPA is providing in this CTG
a one year period for the required submittal of a revised SIP.  Pursuant to section
182(b)(2), States required to submit rules consistent with section 182(b) must submit
their SIP revisions within one year of the date of issuance of the final  CTG for fiberglass
boat manufacturing.

II.     Background and Overview

       The EPA has not published a previous CTG for fiberglass boat manufacturing
materials, but did publish an assessment of VOC emissions from fiberglass boat
manufacturing in 1990. The 1990 assessment defined the nature and scope of VOC
emissions from fiberglass boat manufacturing, characterized the industry, estimated per
plant and national VOC emissions, and identified and evaluated potential control options.

       In 2001, EPA promulgated the National Emission Standards for Hazardous Air
Pollutants for Boat Manufacturing, 40 CFR part 63, subpart WVV (2001 NESHAP).
The 2001 NESHAP established organic hazardous air pollutant (HAP) emissions limits
based on low-HAP resins and gel coats and low-emitting resin application technology.

       Several of the air pollution control districts in California have  specific regulations
that control VOC emissions from fiberglass boat manufacturing operations, as part of
their regulations for limiting VOC emissions from polyester resin operations. Several
other states also have regulations that address VOC emissions from fiberglass boat
manufacturing as part of polyester resin operations. A discussion of the applicability and
control options found in the Federal  actions, the California air district and other State
rules is presented in Section V of this document.

       EPA developed the recommended approaches contained in this document after
reviewing the 1990 VOC assessment, the 2001 NESHAP, and existing California district
and other State VOC emission reduction approaches, and after considering information
obtained since the issuance of the 2001 NESHAP.

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       The remainder of this document is divided into six sections. Section III describes
the scope of sources to which the control recommendations in this CTG could apply.
Section IV describes the fiberglass boat manufacturing processes and identifies the
sources of VOC emissions from those processes. Section V describes the available
control approaches for addressing VOC emissions from this product category and
summarizes Federal, State and local approaches for addressing such emissions. Section
VI provides our recommendations for RACT for fiberglass boat manufacturing materials.
Section VII discusses the cost-effectiveness of the recommended control approaches.
Section VIII contains a list of references.

III.    Applicability

       This CTG provides control recommendations for reducing VOC emissions from
the use of gel coats, resins, and materials used to clean application equipment in
fiberglass boat manufacturing operations. This section addresses EPA's recommendations
as to the scope of entities to which the RACT recommendations in this CTG should
apply. As explained above, this document is a guidance document and provides
information for States to consider in determining RACT. When State and local pollution
control agencies develop RACT rules, they may elect to adopt control approaches that
differ from those described in this document and/or promulgate applicability criteria that
differ from those recommended here.

       This CTG applies to facilities that manufacture hulls or decks of boats from
fiberglass, or build molds to make fiberglass boat hulls or decks (hereinafter referred to
as "fiberglass boat manufacturing facilities"). We do not extend our recommendations in
this CTG to facilities that manufacture solely parts of boats (such as hatches, seats, or
lockers), or boat trailers, but do not manufacture hulls or decks of boats from fiberglass,
or build molds to make fiberglass boat hulls or decks. If a facility manufactures hulls or
decks, or molds for hulls or decks, then the manufacture of all other fiberglass boat parts,
including small parts such as hatches, seats, and lockers is also covered.

       We recommend that the control  approaches discussed in Section VI of this CTG
apply to each fiberglass boat manufacturing facility where the total actual VOC emissions
from all fiberglass boat manufacturing operations covered by the recommendations in
Section VI of this CTG are equal to or exceed 6.8 kg/day (15 Ib/day). An alternative
equivalent threshold would be 2.7 tons per 12-month rolling period. Cleaning materials
should be included in determining whether total actual VOC emissions exceed this level.
If a facility has add-on controls, then emissions before the add-on controls should be used
in determining if a facility meets this threshold.

       The control approaches discussed in Section VI of this CTG do not extend to
surface coatings applied to fiberglass boats, and do not apply to industrial adhesives used
in the assembly of fiberglass boats.  Surface coatings for fiberglass and metal recreational
boats (pleasure craft) are addressed in the CTG for miscellaneous metal parts and plastic
parts surface coating.  Industrial adhesives used in boat assembly are addressed in the
CTG for miscellaneous industrial adhesives.  Polyester resin putties used to assemble
fiberglass parts, however, are not considered adhesives and are addressed in this CTG.

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       We do not recommend the control approaches discussed in this CTG for facilities
that emit below 6.8 kg/day because of the very small VOC emission reductions that could
be achieved.  Such a level is considered to be very low within the fiberglass boat
manufacturing industry and is expected only from facilities producing only small
numbers of small boats (such as specialty kayaks or canoes). Furthermore, based on the
2002 National Emission Inventory (NET) and the 2004 ozone nonattainment designations,
we estimated that most of the fiberglass boat manufacturing facilities located in ozone
nonattainment areas (67 out of 91 facilities) emit at or above this level.  Therefore, these
facilities would be addressed by our recommendations in the CTG. As mentioned above,
for purposes of determining whether a facility meets our recommended applicability
threshold, aggregate emissions, before consideration of control, from all fiberglass boat
manufacturing operations (including related cleaning activities) at a given facility are
included.

       In developing their RACT rules, State and local agencies should consider
carefully the facts and circumstances of the affected sources in their States. As noted
above, States can adopt the above recommended 15 Ib/day actual VOC emissions or an
equivalent applicability threshold, or they can develop other applicability criteria that
they determine are appropriate, considering the facts and circumstances of the sources in
their particular nonattainment areas. EPA will review the State RACT rules in the context
of the SIP revision process.

       Two items were used  as sources of emissions data and statistical information
concerning the fiberglass boat manufacturing industry as a whole. These were the 2002
National Emission Inventory (NET) and  industry survey data collected by EPA during the
development  of the 2001 NESHAP. The NESHAP data provided by industry represented
operations in  1996 and 1997.

       The NESHAP data indicate that styrene and methyl methacrylate (MMA),
which are both VOC  and organic HAP, account for nearly all the VOC emissions, as
well as HAP emissions, from fiberglass boat manufacturing facilities. Therefore, total
HAP and VOC emissions from fiberglass boat manufacturing facilities are nearly equal.
The 2001 NESHAP estimated that baseline HAP emissions from boat manufacturing
were 9,920 tons per year (tpy)a, and we can assume that this estimate represents nearly
all the VOC emissions as well.

       In developing this CTG, the 2002 NEI database was queried for VOC emissions
generated by facilities that were listed under SIC 3732, boat building and repairing. This
query resulted in 223  facilities with total VOC emissions of 9,100 tpy. In the Federal
Register notice of November 17, 2005 regarding the  changes to the Section 183(e)
category list and schedule for regulation, EPA reported that VOC emissions from
fiberglass boat manufacturing materials, based on the 1995 NEI, were 11,000 Mg/yr
(12,100 tpy).b The general agreement among the 2002 NEI VOC emissions, the 2001
NESHAP HAP emissions, and the 1995 NEI VOC emissions estimates, taking into
a 66 FR 44,222. August 22, 2001.
b 70 FR 69,760. November 17, 2005.

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account possible changes in the industry over time, indicates that the query of the 2002
NEI provides a reliable estimate of the number of facilities and total VOC emissions
from fiberglass boat manufacturing materials.

IV.    Process Description and Sources of VOC Emissions

       Several types of boats are manufactured in the United States, including sailboats,
powerboats, yachts, personal watercraft, and small miscellaneous boats such as kayaks
and canoes. These boats are manufactured from a variety of materials, including, but not
limited to, fiberglass (also known as fiber reinforced plastic or FRP), aluminum,
rotationally molded (rotomolded) polyethylene, and wood.  Fiberglass is the most
common material used in boat manufacturing and is the focus of this CTG.

A.     Process Description

       Boats made from fiberglass are typically manufactured in a process known as
open molding.  Separate molds are typically used for the boat hull, deck, and
miscellaneous small FRP parts such as fuel tanks, seats, storage lockers, and hatches. The
parts are built on or inside the molds using glass roving, cloth, or matc that is saturated
with a thermosetting liquid resin such as unsaturated polyester or vinylester resin. The
liquid resin is mixed with a catalyst before it is applied to the glass, which causes a cross-
linking reaction between the resin molecules. The catalyzed resin hardens to form a rigid
shape consisting of the plastic resin reinforced with glass fibers.

       The fiberglass boat manufacturing process generally follows these production
steps:

       1) Before each use, the molds are cleaned and polished and then treated with a
mold release agent that prevents the part from sticking to the mold.

       2) The open mold is first spray-coated with a clear or pigmented polyester resin
known as a gel coat. The gel coat will become the outer surface of the finished part. The
gel coat is mixed with a catalyst as it is applied so that it will harden. The catalyst can be
mixed either inside the spray gun (internal mix) or immediately after leaving separate
orifices on the spray gun (external mix). The gel coat is applied to a thickness of about 18
mils (0.018 inches). Clear gel coats are often mixed with metal flakes to create an
automotive-type metallic finish over a pigmented gel coat. Pigmented gel coats are used
when a solid color surface is desired.  Most gel coats are pigmented.  Since they do not
have any pigments, clear gel coats usually have a higher VOC content than pigmented gel
coats.
0 Roving is a bundle of continuous glass fibers that is fed from a spool to a specialized gun that chops the
roving into short fibers, mixes them with catalyzed resin, and deposits them on the mold surface in a
random pattern. Cloth is a fabric made of woven yarns of glass fibers.  Mat is a prepared material
consisting of short glass fibers that are fixed to each other in a random pattern by a chemical binder, or are
mechanically stitched to a lightweight fabric.

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       3) After the gel coat has hardened, the inside of the gel coat is coated with a skin
coat of polyester resin and short glass fibers (either glass mat or chopped roving) and
then rolled with a metal or plastic roller to compact the fibers and remove air bubbles.
The skin coat is about 90 mils (0.09 inches) thick and is intended to prevent distortion of
the gel coat (known as "print through") from the subsequent layers of fiberglass and
resin;

       4) After the skin coat has hardened, additional glass reinforcement in the form of
chopped roving, chopped strand mat, or cloth is applied to the inside of the mold and
saturated with catalyzed polyester resin. The resin is usually applied with either
mechanical equipment or by hand using a bucket and brush or paint-type roller.

       5) The saturated fabric is then rolled with a metal or plastic roller to compact the
fibers and remove air bubbles.

       6) More layers or "laminations" of woven glass or glass mat and resin are applied
until the part is the desired thickness.  The part is then allowed to harden while still in the
mold. As the part cures it generates heat from the exothermic reactions that take place as
the resin hardens; very thick parts may be built in stages to allow this heat to dissipate to
prevent heat damage to the mold or part.

       7) After the resin has cured, the part is removed from the mold and the edges are
trimmed to the final dimensions.

       8) The different FRP parts of the boat are assembled using small pieces of woven
glass or glass mat and resin, adhesives, or mechanical fasteners. Polyester resin  mixed
with fillers to create putty is also often used to assemble fiberglass parts and to fill gaps
between parts. The putty becomes part of the composite structure. The putties may be
applied by hand, or by using mechanically powered equipment similar to a large caulking
gun.

       9) The interior surfaces of the boat may be coated, either by spray or brush, with
pigmented gel coat that serves as a surface finish so the interior spaces have a uniform
color.

       10) Flotation foam is typically injected into closed cavities in the hulls of smaller
boats to make the boat unsinkable and capable of floating upright if swamped.

       11) After the assembly of the hull is complete, the electrical and mechanical
systems and the engine are installed along with carpeting, seat cushions, and other
furnishings,  and the boat is prepared for shipment.

       12) Some manufacturers paint the topsides of their boats to obtain a superior
finish or the bottoms to prevent marine growth.  However, this is not a common  practice.

       13) Larger boats generally also require extensive interior woodwork and  cabin
furnishings to be installed.

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       As mentioned above, fiberglass boat manufacturing facilities covered by this CTG
include facilities that construct the molds or "tools" that are used to build the separate
parts of the fiberglass boat.  Most fiberglass boat manufacturers also build their own
molds, although some obtain molds from facilities dedicated to building molds, either at a
separate facility within a larger company, or as a completely separate entity.  The
production of molds is done using specialized resins and gel coats referred to as tooling
resin and gel coat.  These differ from production resin and gel coat in that they are harder,
more heat resistant, and more dimensionally stable than production materials.

       Construction of a mold begins with the construction of a full-size model of the
part to be manufactured. This model is often called a "plug" and the mold is eventually
built over the finished plug. The plug is built from rigid foam that is carved to shape.
The foam is then covered with tooling resin and fiberglass and then a layer of tooling gel
coat, and then sanded to its final shape and then polished and waxed so the mold will not
stick to it when the mold is finished.

       The mold is then built over the plug using tooling gel coat and resin and
fiberglass. The tooling gel coat will become the interior surface of the mold, supported
by the resin and fiberglass.  The tooling resin often has inert filler added to it so it is more
dimensionally stable and is able to absorb more heat from the part during the molding
process. A metal framework is also added to the exterior of the mold to support the mold
after it is removed from the plug.  When the mold is removed from the plug, the mold
will have a cavity or exterior surface that is the exact opposite of the shape of the plug
and parts that will produced. The interior surface of the mold is polished and waxed so
that finished parts will not stick the mold surface and they can be removed.

       A single mold can be used to make many copies of the same part. Occasionally a
mold may need to be repaired  if the surface is damaged during part removal.  These
repairs are done using tooling resin and gel  coat to which extra styrene has been added so
the repair material will bond to the existing mold surfaces.

B.     Sources of VOC Emissions
       Styrene  and methyl methacrylate (MMA) are the primary VOC  emitted from
fiberglass boat manufacturing  materials.  The resins  contain styrene and the gel coats
contain both compounds.  Styrene and MMA are monomers.  A monomer is a volatile
organic compound  that partially combines with itself, or other similar compounds, by a
cross-linking reaction to become a part of the cured resin.  A fraction of each monomer
compound evaporates during resin and gel coat application and curing.  Not all of the
styrene and MMA evaporate, because a majority of these compounds are bound in the
cross-linking reaction between polymer molecules in the hardened resin or gel coat and
become part of the  finished product. In closed molding operations, nearly all of the
monomers are bound in the cross-link reactions and emissions are very low.  In the
remainder of this CTG, these monomers in resins and gel coats are referred to as
monomer VOC. Styrene and MMA are the only monomer VOC we have identified in the
resins and gel coats used in fiberglass boat manufacturing.

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       The fraction of monomer VOC that is emitted from resin and gel coat used for
fiberglass boat manufacturing is dependent on several factors, including the initial
monomer VOC content of the material, the application method, and the thickness of the
part or layer that is curing. Monomer VOC emission rates are usually expressed in terms
of Ib monomer VOC emitted per ton of material applied (Ib/ton), or kilogram per
megagram (kg/Mg).  Monomer VOC evaporation from gel coats is higher than from
resins because gel coats are applied in thinner coats, which increases evaporation.  When
material is applied in thicker layers, the overlying material impedes evaporation from the
underlying material, so a higher fraction is bound up during the cross linking reactions
before it has a chance to evaporate.

       Higher monomer VOC materials also tend to emit a higher fraction of the
monomer VOC than lower monomer VOC materials. Therefore, lowering the monomer
VOC content of the resin or gel coat has a two-fold effect: first, it decreases the amount
of monomer VOC that could be emitted, and second, a smaller fraction of the monomer
VOC that is present is emitted to the atmosphere.

       The type of application equipment used also affects the fraction of monomer VOC
that is emitted.  Spray application equipment that atomizes the resin as it is applied
creates small droplets with a high surface-to-volume ratio that increases the amount of
monomer VOC that evaporates during application.  Non-atomizing application methods
minimize the surface area during application and reduce monomer VOC emission rates.
These non-atomizing methods include resin flow coaters, which create consolidated
streams of resin (like a shower head) instead of atomized droplets, pressure fed resin
rollers that apply resin directly onto the part,  and fluid impingement technology which
creates large droplets.

       Resins and gel coats may also contain non-monomer VOC that are not reactive
and do not become part of the hardened resin or gel coat. All of the non-monomer VOC,
if present, is assumed to be emitted.  However, the non-monomer VOC constitute less
than 5 percent of the total VOC in all resins and gel coats and usually comprise less than
1 percent of each resin or gel coat, by weight. Many resins and gel coats do not contain
reportable amounts of non-monomer VOC, based on a review of material safety data
sheets (MSDS) for resins and gel coats.

       Resin and gel coat application equipment requires solvent cleaning to remove
uncured resin or gel coat after each use. The solvents used to clean the application
equipment are also a potential source of VOC emissions.d Catalyzed resin or gel coat
d In a Federal Register notice, EPA stated that the cleaning operations associated with certain specified
section 183(e) consumer and commercial product categories, including fiberglass boat manufacturing,
would not be covered by EPA's 2006 CTG for industrial cleaning solvents (71 FR 44522 and 44540,
August 4, 2006). In the notice, EPA expressed its intention to address cleaning operations associated with
these categories in the CTGs for these specified categories if the Agency determines that a CTG is
appropriate for the respective categories. Accordingly, this draft CTG addresses VOC emissions from
cleaning operations associated with fiberglass boat manufacturing.

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will harden in the transfer hoses or application equipment if not flushed with a solvent
after each use.

V.     Available Controls and Existing Federal, State, and Local
       Recommendations/Regulations

       As previously mentioned, there are two main sources of VOC emissions from
fiberglass boat manufacturing materials: (1) evaporation of VOC (i.e., both monomer and
non-monomer VOC) from the gel coats and resins; and (2) evaporation of VOC from the
cleaning materials. This section summarizes the available control options for reducing
these VOC emissions and existing federal, State, and local VOC recommendations or
requirements that address these emissions.

A.     Available Control Options for Resin and Gel Coat

       As mentioned above, all of the non-monomer VOC in the resins and gel coat
materials, if present, is assumed to be emitted. We are not aware of any control measure
currently being implemented to reduce non-monomer VOC emissions from resins and gel
coats used in fiberglass boat manufacturing. However, there are available options for
controlling monomer  VOC emission from these materials. These control options for
monomer VOC emissions are described below.

1.  Low monomer VOC Resins and Gel Coats

       Reducing monomer VOC emissions from resins and gel coats used in open
molding at fiberglass  boat manufacturing facilities is achieved primarily by reducing the
monomer VOC content of the materials (resin and gel coat) and by switching to non-
atomizing resin application methods.

       Industry and EPA-sponsored testing has experimentally measured the amount of
VOC that is emitted, and formulae were developed to predict the VOC emission rates (Ib
VOC/ton of material applied) for different materials and application methods.6 The resin
and gel coat that were used in testing contained only monomer VOC (i.e., styrene and
MMA); they did not contain non-monomer VOC.
       The different resins and gel coats can be reformulated to achieve varying levels of
lowered monomer VOC contents, depending of their use in boat manufacturing. Because
reducing the monomer VOC content reduces emissions by two interacting mechanisms
(reducing the amount of monomer VOC available to be emitted and by reducing the
fraction of monomer VOC that is emitted), monomer VOC emission reduction is not
linearly related to monomer VOC content.  For example, reformulating a resin from 40
e This testing was done in conjunction with the development of the NESHAP for boat manufacturing (40
CFR 63, subpart VVVV) and the NESHAP for reinforced plastic composite manufacturing (40 CFR 63,
subpart WWWW).  The formulae that were developed were incorporated into both of these final NESHAP.

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percent monomer VOC, by weight, to 35 percent monomer VOC, achieves a 28 percent
VOC emission reduction if the resin is applied with atomizing spray methods.

       With low-monomer VOC resins and gel coats, facility operators can achieve
emission reductions without changes in  equipment or work practices.  Low-monomer
VOC materials can also be combined with other emission reduction techniques, such as
non-atomizing resin application, for additional emission reductions. For regulatory
agencies, a low-monomer VOC material requirement is easy to monitor and enforce; it is
also relatively easy for a facility to demonstrate compliance on a continuous basis.

2.  Vapor Suppressed Resins and Gel Coats

       Vapor suppressed resins and gel coats can be used to reduce monomer VOC
emissions, but they can present manufacturing problems when used for boat
manufacturing.  Vapor suppressed resins and gel coats have an additive, typically a wax,
to reduce monomer VOC evaporation by forming a film on the surface of the resin or gel
coat as it cures. Monomer VOC reductions of up to 40 percent have been measured for
atomizing spray-applied vapor suppressed resin compared to conventional resins; no data
are available for vapor-suppressed gel coats. Vapor suppressed resins and gel coats can
be used to achieve emission reductions without changes in equipment.  Vapor suppressed
resins can also be combined with other emission reduction techniques,  such as non-
atomized resin application, for additional emission reductions.

       However,  adding a vapor-suppressing wax to a resin or gel coat may present
significant technical problems in boat manufacturing. Because boats are relatively large
and complex  structures, they are usually built and assembled from subassemblies that
must be bonded together.  In order to achieve good secondary bondsf between parts made
with vapor suppressed resins, the wax film on the bonding surfaces must be removed,
usually by sanding or grinding, before the parts can be bonded. This additional  surface
preparation can be labor intensive; one California manufacturer estimates that switching
to vapor-suppressed resins caused a 25-percent labor increase in building parts.  More
importantly, the ultimate strength of those secondary bonds may also be reduced,
increasing the possibility of structural failure among assembled parts.

       Vapor suppressed gel coat can be used only in limited applications because the
wax will  also prevent bonding with the gel coat. Since gel coats are applied in a thin
layer, the wax cannot be removed to allow bonding with additional layers of material.
Therefore, vapor suppressed gel  coat can only be used where additional layers will not be
added.  Vapor suppressed gel coat can be used to coat interior spaces of assembled boats
where the gel coat is only being used as the final surface finish. Vapor suppressed gel
coat is  typically used in this application because the curing of all polyester resins is
f "Primary bonds" are created when additional resin and fiberglass is applied to resin that is still wet and
has not cured.  "Secondary bonds" are created when additional resin and fiberglass is applied to resin that
has fully cured, such as when parts are assembled and bonded together with more fiberglass and resin.
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inhibited by exposure to the air, and the wax additive ensures complete curing of the gel
coat surface.8

3.  Non-atomizing Resin Application

       Changing resin application methods can also reduce monomer VOC emissions.
For example, switching from atomizing to non-atomizing application of a resin with 35
percent styrene achieves a 41 percent emission reduction. If both styrene content and
application method are changed to reduce emissions, the reductions can be greater than
changing just the resin styrene content or application method alone. For example,
changing from atomized application of resin with 40 percent styrene, to resin with 35
percent styrene that is applied with nonatomizing technology can achieve a 58 percent
emission reduction.

       Currently, nonatomizing technology is feasible for applying production and
tooling resins only.  Gel coats must still be applied with atomizing spray guns, so
monomer VOC reductions from gel coat can only be achieved through the use of low
monomer VOC gel coats.  The only exception is gel coat that may be applied with a
brush or roller to the interior areas of finished boats where the cosmetic appearance is not
as critical as on the exterior.

       Non-atomized resin application includes five different techniques for applying
resin: bucket and brush application by hand, resin rollers, flow coaters,  resin
impregnators, and fluid impingement technology. All five of these techniques reduce
emissions compared to atomized resin spraying techniques by eliminating the atomization
of resin. The emission reductions are generally greater for higher styrene resins.

       Bucket and brush application is the oldest method of applying resin to fiberglass
reinforcements. Individual batches of resin are  mixed with a catalyst in a bucket or pail
and applied to the part by hand using a brush or paint roller. This technique was the first
method used in fiberglass boat manufacturing until spray equipment and chopper guns
were developed for applying resin.  Currently, it is used only in limited cases for low
volume production or custom work, or for fabricating small parts and bonding parts at
larger production facilities.

       Pressure fed resin rollers consist of a fabric roller that is fed a continuous supply
of resin from a mechanical fluid pump. The fluid pump draws resin from a drum or bulk
distribution line.  The resin pump is mechanically linked to a separate catalyst pump.
These two pumps supply the resin and catalyst  in a preset ratio to a mixer in the handle of
the roller. The mixer then feeds the catalyzed resin to the roller head through the handle
of the roller. A valve controlled by the operator regulates the amount of resin flowing to
the roller head and to the part being fabricated.  The roller head is covered with a
disposable fabric cover similar to a standard paint roller cover. Resin rollers are intended
to be operated almost continuously during a shift to prevent the resin from hardening
8 In other cases, the gel coat and resin becomes fully cured because the surface is blocked from the air by
the subsequent layers of material that are added to the part.
                                                                                11

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between the mixer and the roller cover.  At the end of the shift, the roller cover is
discarded and the mixing unit, handle, and roller manifold are flushed with a solvent.

       Flow coalers are similar to standard resin spraying equipment except that the
resin leaves the tip of the flow coater in continuous consolidated streams rather than as an
atomized spray. Whereas the tip of a spray gun is a single small orifice, the tip of a flow
coater has a dozen or so precisely drilled holes that produce steady streams of resin,
similar to a small showerhead. Flow coaters can also be fitted with a chopper head to
apply chopped fiberglass roving in the same way as a conventional atomized chopper
gun. The flow coaters use the same resin and catalyst pumps that are used with catalyst-
injected spray equipment or resin rollers. Like resin rollers and other internal mix
equipment, flow coaters are intended to be operated almost continuously during a shift to
prevent the resin from hardening inside the applicator. At the end of the shift, the gun
and nozzle are flushed using a solvent.

       Fabric impregnators use resin covered rollers to saturate fiberglass fabric, similar
to an old-fashioned wringer washer in reverse. Dry fabric is fed down through a pair of
finished-metal rollers that hold a reservoir of resin to impregnate or saturate the fabric.
The gap between the rollers can be adjusted to achieve a predetermined fiber-to-resin
ratio. Catalyzed resin can be manually mixed  and poured into the machine or
continuously mixed and fed to the machine by fluid pumps that are similar to those used
for resin spray equipment.

       Fabric impregnators are available in a  variety of sizes. Small table top units are
available for impregnating narrow reinforcing tapes. Larger impregnators can be
mounted on mobile bridge cranes so that impregnated fabric can be lowered directly from
the impregnator into a large open mold.

       Fluid impingement technology consists of a gun that dispenses two streams of
resin that come together to form a fan of large droplets. The large size of the droplets
minimizes emissions compared to atomized spray application. This technology is
reported to be the most widely used non-atomizing technology used to apply resin.

4. Closed Molding

       Closed molding is the name given to fabrication techniques in which  reinforced
plastic parts are produced between the halves  of a two-part mold, or between a mold and
a flexible membrane, such as a bag. There are four types of closed molding methods that
are being used in fiberglass boat manufacturing: vacuum bagging, vacuum-assisted resin
transfer molding, resin transfer molding, and compression molding with sheet molding
compound. Closed molding processes as they are currently practiced cannot be used to
reduce emissions during gel coat or skin coat  application, because these applications must
still use conventional open molding techniques. However,  closed molding can be used to
reduce monomer VOC emissions from the subsequent laminating steps after  the gel coat
and skin coat layers have been applied.
                                                                               12

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       Closed molding is generally applicable to making a large number of small parts,
such as hatches and locker doors, or small numbers of high performance boat hulls and
decks, but it is not feasible to replace open molding with closed molding at all types of
boat manufacturing facilities. However, as discussed below, one major fiberglass boat
manufacturer has developed a patented closed molding process that has replaced open
molding for the hulls of many of its smaller (17 to 22 feet long) powerboats.

       Vacuum bagging is a partially closed molding technology. It uses techniques
similar to open molding but with a modification in the resin curing stage. After resin and
fiberglass have been applied, a flexible, clear plastic sheet is placed over the wet laminate
and sealed along the edge of the mold to form a  "bag." A porous material called a
bleeder sheet  is also placed under the bag and a hose connected to a vacuum pump is
sealed under the edge of the bag. The vacuum pump is used to draw the air out from
under the bag and press the bag down onto the part.  The pressure of the vacuum removes
any trapped air and excess resin from the part and presses the layers of laminated material
together.  This technique is used to increase the fiber-to-resin ratio, which generally
increases the strength of a part,  and also to obtain a good bond between FRP skins and
non-FRP core materials, such as wood or foam.  Core materials are often sandwiched
between layers of FRP to make a thicker and stiffer part without significantly increasing
the part's weight. The EPA believes that most facilities that perform vacuum bagging use
it only  for fabricating small parts and not for hulls, decks, and superstructures.

       No data are available to quantify the emission reductions associated with vacuum
bagging.  However, approximately 50 percent of emissions during lamination occur
during  the curing stage after the resin has been applied.  Since the vacuum bag covers the
part during resin curing, vacuum bagging may reduce a significant fraction of these
curing  emissions.  The emission reductions will  depend on how quickly the resin is
covered with the vacuum bag.

       Vacuum-Assisted Resin  Transfer Molding (VARTM) is a closed molding
technology that uses a vacuum to pull resin into  dry fiberglass reinforcements that are
placed  into a closed mold. The closed mold may be formed using a flexible plastic sheet
or "bag" as in vacuum bagging, or by a rigid or semi-rigid cover that matches the shape
of the mold. In all variations, the bag or cover is sealed to the mold and vacuum pressure
is used to draw resin from an outside reservoir into the sealed mold through a system of
distribution tubes and channels  placed under the bag or cover.

       One VARTM process that has been used by several boat manufacturers is a
patented technology called the Seeman Composites Resin Infusion Molding Process
(SCRIMP) which is licensed by SCRIMP Systems, LLC.  In the SCRIMP  process, the
mold is coated with a gel coat finish and a skin coat is applied using conventional
techniques. Dry reinforcements and core materials are then placed in the mold. The resin
distribution system and the bag are then placed over the mold and sealed to the edge of
the mold. The vacuum is then applied to pull the bag against the mold and the
reinforcements and the bag is checked for leaks. Valves to the resin supply system are
then opened and the resin is pulled into the reinforcements by the vacuum.  When the
reinforcements are thoroughly saturated with resin, the resin supply is shut off and the
                                                                               13

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part is allowed to cure under a vacuum. After curing, the bag is removed and is either
discarded or reused, depending on the material from which it is made. Disposable bags
are made from plastic film, whereas reusable bags are made from silicone rubber. A
silicone bag can be used for more than 500 parts.

       Another patented closed molding process is  called the Virtual Engineered
Composites® (VEC®) process. In this process, resin is injected into a rigid closed mold
that is already loaded with the dry fiberglass reinforcements. The process is computer
controlled and the mold components can be reused many times.  The company that owns
this process has used it to replace open molding in the manufacture of relatively large
numbers of small (17 to 22 foot) powerboats.

       The VARTM and VEC® processes can significantly reduce emissions during
lamination because the resin is drawn from a bulk container and distributed under an
airtight bag or cover, so very little resin is exposed to the atmosphere.  These processes as
they are currently practiced cannot be used to reduce emissions during gel coat and skin
coat application because these steps must still use conventional open molding techniques.

       Resin transfer molding (RTM) uses two rigid mold halves to provide the shape for
fabrication of FRP boat parts. In a typical RTM operation, gel coat is spray applied to the
inside surface of both halves of the mold so that the part has two finished sides, instead of
one as in open molding. After the gel coat cures, the dry reinforcement is laid inside the
mold and the mold is closed with clamps. When closed, the two halves of the mold mate
together with a narrow space between them equal to the thickness of the finished part.
Catalyzed resin is injected into the  closed mold where it saturates the fiberglass. While
the part is  still in the mold, the resin cures.  After the resin has cured, the mold is opened
and the finished part is removed.

       The RTM process is most economical for making many copies of small parts,
especially when a smooth finish is desired on both sides of the part. Typical applications
of RTM in boat manufacturing are for making hatch covers, doors, and seats. No
emissions  data are available from the RTM process; however, because the resin is not
exposed to the air during application or curing, the EPA predicts that little monomer
VOC is emitted during fabrication by RTM compared to conventional hand and spray
processes. Any monomer VOC that is emitted is released during off-gassing when the
mold is opened.

       Compression molding involves the use of a prepared compound such as sheet
molding compound (SMC) and a large hydraulic press to produce FRP parts. The
prepared SMC sheet is composed of resin and fiberglass fibers. To create a FRP part with
compression molding, SMC sheets are cut to the proper size and put into a matched male
and female mold. The two molds are pressed together in the hydraulic press under several
tons of pressure. The SMC is forced into all areas of the mold and cures in the closed
mold under high heat and pressure in a matter of minutes. Several facilities are currently
using compression molding with SMC to produce hulls, decks, and other parts for
personal watercraft (PWC), such as those known under the trade name Jet Ski®.
                                                                              14

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       No emissions data are available from the compression molding with SMC
process; however, because the resin is not exposed to the air during application or curing,
the EPA predicts that little monomer VOC is emitted during fabrication with SMC
compared to open molding resin application processes.
                                                                              15

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5.  Add-On Control Systems

       No facilities in the fiberglass boat manufacturing industry currently use add-on
controls to reduce VOC emissions.  The majority of VOC emissions from resin and gel
coat in an open molding process occur in an open shop environment. Some emissions
occur in spray booths where gel coat spraying for smaller parts may be done. The
volume of air exhausted from the open shop or from spray booths is typically high, and
the VOC concentration is typically low.  Therefore, it is not cost-effective to use add-on
controls to reduce VOC emissions from  fiberglass boat manufacturing. Because of the
wide availability and lower cost (compared to add-on controls) of low-monomer VOC
content materials and alternative application methods, these materials and methods are
used to reduce monomer VOC emissions from fiberglass boat manufacturing facilities.

B.     Available Control Options for Mixing Containers

       Resin and gel coat materials are usually stored and prepared for application in
large containers, either large stationary tanks or 55  gallon drums.  Before application,
promoters may be added to the material  to promote the cross linking reaction after the
resin is mixed with catalyst.  Thixotropic agents may also be added so that resin and gel
coat will hold onto vertical surfaces without running while still in a liquid state.  Since
the material in these containers may be agitated to mix in these additives and to keep
them mixed in during application, these  containers  are a potential source of VOC
emissions.

       To reduce VOC emissions from tanks or drums used to mix materials containing
VOC, these containers can be sealed with tightly fitting covers during mixing operations.
These covers can be modified with openings to allow the mixing and pumping equipment
into the container, but these openings  can also be sealed to reduce VOC emissions.

C.     Available Control Options for Cleaning Materials

       Organic solvents are commonly used to clean application equipment, including
resin and gel coat spray guns and other mechanical applicators, as well as rollers and
other hand tools. These organic solvents include acetone, methyl ethyl ketone (MEK),
lacquer thinner, Stoddard solvent, or toluene.  Water-based emulsifiers with low VOC
content and organic solvents with low vapor pressures can also be used to clean the
application equipment.

       To control VOC emissions from  cleaning materials, facilities can use water-based
emulsifiers that are low VOC, as well as organic solvents  (e.g., dibasic esters, DBE) with
low vapor pressures. Commonly used water-based emulsifiers in the fiberglass boat
manufacturing industry contain less than 5 percent VOC by weight. Dibasic esters have
vapor pressures of 0.5 mm Hg or less, at 68 ° F, so  they have very low evaporation rates
and little of the material is lost during use.  These materials can typically be recovered
and recycled by the vendor. Many facilities already use both water-based emulsifiers and
DBE to clean resin and gel coat application equipment.
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D.     Existing Federal, State, and Local Recommendations/Regulations

       The following discussion is a summary of EPA, State, and local actions that
address VOC emissions from fiberglass boat manufacturing.

1. The 1990 National VOC Assessment

       In 1990, the EPA completed an "Assessment of VOC Emissions from Fiberglass
Boat Manufacturing" (EPA/600/S2-90/019).  This document characterized the fiberglass
boat manufacturing industry and its processes, assessed the extent of VOC emissions
from this industry, and evaluated various control options. The assessment described open
molding and discussed types of closed molding in use at the time. The assessment
determined that acetone (no longer considered a VOC) and styrene were the two primary
VOC emitted from the industry, and the major sources of emissions were resin and gel
coat applications, and evaporation of solvents during clean-up.

       The 1990 assessment discussed process changes and add-on controls to reduce
emissions.  Specifically, it recommended substituting the high-VOCh resins and gel coats
that were commonly used at that time with low-VOC resins (e.g., 35 percent  styrene) and
gel coats, and vapor suppressed resins. The document discussed add-on controls, but
considered such controls not economically feasible for use in fiberglass boat
manufacturing due to high exhaust flow rates and low VOC concentrations. The
document also recommended using water-based emulsifiers and low vapor pressure
dibasic ester (DBE) compounds for equipment cleaning.

2. The 2001 NESHAP  for Boat Manufacturing

       In 2001, EPA promulgated the National Emission Standards for Hazardous Air
Pollutants for Boat Manufacturing, 40 CFR part 63, subpart VWV (2001 NESHAP).
The 2001 NESHAP established organic hazardous air pollutant (HAP) emissions limits
based on low-HAP resins and gel coats and low-emitting resin application technology.  It
also established limits to reduce emissions from cleaning operations and resin and gel
coat mixing containers.

       The 2001 NESHAP applies to fiberglass boat manufacturers that are major
sources of HAP emissions.  Major sources are stationary sources that emit, or have
the potential to emit, (considering controls) 10 tpy or more of any one HAP, or 25
tpy or more of any combination of HAP. The 2001 NESHAP regulated the
following, with certain exceptions:

 •      All open molding operations, including pigmented gel coat, clear gel coat,
       production resin, tooling resin, and tooling gel coat;

 •      All closed molding resin operations;

 •      All resin and gel coat application equipment cleaning; and
1 In this 1990 document, the authors did not distinguish between monomer and non-monomer VOC.


                                                                              17

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 •     All resin and gel coat mixing operations.

       The 2001 NESHAP regulates the total HAP content in the materials used in each
regulated operation.  Specifically, the 2001 NESHAP sets a HAP content limit for each
regulated open molding resin and gel coat operation.  For each regulated open molding
resin operation, the NESHAP established separate HAP content limits for atomized and
non-atomized resin application methods. A summary of the limitations is provided in
Table 1 of this CTG.
        Table 1. Organic
     Gel Coat Operations
HAP Content Requirements for Open Molding Resin and
as Specified in the NESHAP for Boat Manufacturing
  (40 CFR 63, Subpart VVVV)
For this operation--
Production resin operations
Production resin operations
Pigmented gel coat
operations
Clear gel coat
Tooling resin operations
Tooling resin operations
Tooling gel coat operations
And this application method
Atomized
Nonatomized
Any method
Any method
Atomized
Nonatomized
Any method
Subpart VVVV provides
that you must not exceed
this weighted-average
organic HAP content
(weight percent)
requirement —
28
35
33
48
30
39
40
       For closed molding operations, no limits apply to the resin application operation if
it meets the specific definition of closed molding provided in the NESHAP.  If a molding
operation does not meet the definition of closed molding that is provided in the
NESHAP, then it must comply with the applicable emission limits for open molding.

       A manufacturer can demonstrate compliance with the HAP emissions limit for the
facility by any of the following alternatives, either alone or in combination:

          •  Ensure that all materials used in a particular open molding operation meet
             the HAP content requirements summarized in Table 1;

          •  Comply with the HAP content requirements in Table 1 on a weighted-
             average basis for all materials used within an operation, calculated on a
             rolling 12-month compliance period;

          •  Averaging emissions among operations and ensure that overall emissions
             do not exceed those that would occur if each operation complied
             separately using low-HAP materials and  application methods. The facility
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              would use "MACT Model Point Value Formulas" provided in the
              NESHAP to estimate HAP emission rates (kg HAP/Mg material used) for
              each operation and to average among operations.  The facility would also
              use a separate equation in the rule to estimate the emissions that would
              occur if each operation complied separately using low-HAP materials and
              application methods; or

          •   Use an emission capture system and add-on control device to ensure that
              overall emissions do not exceed those that would occur if each operation
              complied separately using low-HAP materials and application methods.

       In addition to the resin and gel coat open molding operations which, as described
above, are subject to HAP content limits or emission rate limits, other operations are
subject to either work practice requirements or HAP content limits in the 2001 NESHAP.
These operations include resin and gel coat mixing operations in tanks or drums, and
routine resin and gel coat application equipment cleaning operations.

       Resin and gel coat mixing containers with a capacity of 208 liters (55 gallons) or
more must be covered with tightly fitted lids.  Routine resin and gel coat application
equipment cleaning operations must use solvents containing no more than 5 percent
HAP, but solvents used to remove cured resin or gel coat from equipment are exempt
from the HAP content limits. However, the containers used to hold the exempt solvent
and to clean equipment with cured resin and gel coat must be covered, and there is an
annual limit on the amount of exempt solvent that can be used.

3. Existing State and Local VOC Requirements

       Five States, including California, that have fiberglass boat manufacturing
facilities have State and local regulations to address VOC emissions from fiberglass boat
manufacturing. These rules limit VOC emissions from all types of polyester resin
operations, and treat fiberglass boat manufacturing as a subset of polyester resin
operations.  In California, 16 Air Quality Management Districts (AQMDs) have
regulations for polyester resin operations; there is no statewide rule. The other States
with regulations that address polyester resin operations are Illinois (the Chicago area),
Indiana, Maryland, and Washington (only in the Puget Sound area).

       The existing State regulations are summarized in Table 2.  For California, we
have summarized only a representative sample of the regulations from the 16 AQMDs.
The South Coast Air Quality Management District (SCAQMD) has the most stringent
State or local regulation. Specifically, SCAQMD Rule 1162, (Polyester Resin
Operations) contains monomer VOC content limits for specific types of resins, gel coats,
and cleaning solvents. Furthermore, Rule 1162, requires that all resins have to be applied
with non-atomizing techniques, such as resin rollers, flow coaters, or hand lay up. Rule
1162 also requires that gel  coat must be applied with high efficiency spray equipment,
such as high-volume low-pressure (HVLP), air assisted airless, or electrostatic spray.
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However, the SCAQMD regulation is not as stringent as the 2001 NESHAP.1  The other
AQMD rules in California do not require the use of non-atomized spray application, but
specify that all material spraying use high efficiency spray equipment. The other AQMD
rules also tend to be less stringent than South Coast Rule 1162 because they have higher
allowable monomer VOC contents for resin and gel coat.

       The Illinois rule for the Chicago area, and the Maryland and Puget Sound rules
also require the use of high efficiency spray techniques, but only the Chicago and
Maryland rules have limits for the monomer VOC content of resin and gel coat materials.
These rules are also less stringent than the 2001 NESHAP.

       The Indiana rule has adopted a different approach from other state VOC rules.
The Indiana rule recognizes that since the primary VOC from fiberglass boat
manufacturing (styrene and MMA) are also HAP,  compliance with the 2001 NESHAP
achieves  nearly equal VOC and HAP emission reductions. Therefore, the Indiana rule
provides  that compliance with the 2001 NESHAP  will satisfy the need to achieve best
available control technology (BACT) for new sources that are constructed after 1980.
There are no separate standards for RACT for existing sources in the Indiana rule, but it
is assumed that the 1980 date for new sources will mean that most sources are covered by
the BACT requirement.

       The local and State rules that have been identified also address application
equipment cleaning  operations, either through work practices or VOC content limits on
cleanup materials. Some rules prohibit the use of VOC cleaning solvents, or set very low
VOC limits. This is possible since acetone and methylene chloride, which  are
specifically exempted from the EPA's definition of VOC in 40 CFR 51.100(s), can be
used as clean up solvents. However, boat manufacturers prefer to avoid using acetone
because it is highly flammable, and the use of methylene chloride (a HAP) is regulated at
sources that need to comply with the 2001 NESHAP.

   Table 2. Summary of State and Local Requirements for VOC Emissions from
                          Fiberglass Boat Manufacturing
State
Local Area




California
South Coast
AQMD Rule 1162




Applies to





All polyester resin
operations that
fabricate, rework,
repair,
or touch-up
products for
commercial,
VOC Limit
Applies To




General Purpose
Polyester Resin
Corrosion-
Resistant Resin
(definition
includes boat hulls
and tooling/molds)
Monomer VOC
Limit
(Wt% monomer
VOC in material
unless noted
otherwise)
35

48




Work and
Equipment
Practices



Must use non-
atomized
application for
resin.
Must use high-
efficiency spray
techniques for gel
1 Since styrene and MMA are the primary VOC, as well as the primary HAP, emitted from resin and gel
coat, the HAP limits in the NESHAP and the monomer VOC limits in State and local rules can be
compared directly.
                                                                               20

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State
Local Area

California
Bay Area AQMD
Rule 8-50
California
San Diego APCD
Rule 67-12
Applies to
military, or
industrial use
The manufacturing
of products using
polyester resins.
Exempts touch up
and repair during
manufacture.
Polyester resin
operations, except
marine vessel
repair operations
VOC Limit
Applies To
Fire Retardant
Resin
High Strength
Resin (definition
includes high-
performance boats)
Clear Gel Coat
Monomer VOC
Limit
(Wt% monomer
VOC in material
unless noted
otherwise)
38
40
44
Pigmented Gel Coat:
White and off
white:
Non- White:
Primer:
Specialty Gel Coat
(used with
corrosion resistant,
fire retardant, or
high strength
resins)
Closed Molding
Solvent cleaning
of equipment:
General Purpose
Polyester Resin
Corrosion-
Resistant or Fire
Retardant Resin
Gel coat
Cleaning Materials
General Purpose
Polyester Resin
Corrosion-
Resistant or Fire
45
37
28
48
4% maximum
weight loss during
curing
Comply with
AQMD Rule 1171
VOC content limit
= 25 g/liter
(0.21 Ib/gal)
35
50
250 g VOC/liter of
coating applied
200 g VOC/liter of
cleaning material
35
50
Work and
Equipment
Practices
coat.
Must use high
efficiency spray
equipment for any
spray operations.
Use collecting
system if organic
solvents are used
for equipment
cleaning.
Must use high
efficiency spray
equipment for any
spray operations,
21

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State
Local Area

California
Santa Barbara
APCD Rule 349
Illinois
Rule 2 18, Subpart
CC
Indiana Rule
326IAC8-1-6
Maryland
Rule 26. 11. 19.26
Applies to
that use less than
0.5 gallons of
material per
operating day.
Apply to all
commercial and
industrial polyester
resin operations
that use 50 or more
gallons of styrene
per year.
Chicago Area
New sources
(constructed after
1980) that emit
more than 25 tons
per year of VOC.
Applies where the
total VOC from all
RFC
manufacturing is
20 pounds or more
per day. Does not
apply to resins
used for tooling or
touch up and
repair.
VOC Limit
Applies To
Restardant Resin
Pigmented gel
coats
Clear gel coats
Cleaning materials
General Purpose
Polyester Resin
Corrosion-
Resistant or Fire
Retardant Resin
Pigmented gel
coats
Clear gel coats
Corrosion-
Resistant or Fire
Retardant Resin
High Strength
(>1 0,000 psi
tensile strength),
including tooling
resins
Clear gel coats
Pigmented gel coat
All other materials
Monomer VOC
Limit
(Wt% monomer
VOC in material
unless noted
otherwise)

45
50
200 g VOC/liter,
or, a boiling point
>190C, or use a
VOC reclamation
system (onsite or
offsite), or use less
than 0.5 gallons
average per day
35
50
45
50
48
48
50
45
35
Work and
Equipment
Practices
except for touch up
and repair using a
spray gun with a
container as part of
the gun.
Must use high
efficiency spray
equipment for any
spray operations.
Must use high
efficiency spray
equipment for any
spray operations.
Compliance with 40 CFR 63 subpart VVVV satisfies BACT.
A case-by-case BACT determination is not needed.
No separate standards are specified for RACT.
General Purpose
Polyester Resin
High Strength,
Corrosion-
Resistant, or Fire
Retardant Resin
Gel coat
Cleanup materials
35
50
50
Use non-VOC
cleanup materials
If VOC emissions
are 100 pounds or
more per day, use
airless or air-
assisted spray guns
or non-atomized
application
methods for
general purpose
resin application.
22

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State
Local Area




Washington
Puget Sound Clean
Air Agency
Regulation II,
Article 3, Section
3.08




Applies to





Manufacturing
operations
involving the use
of polyester,
vinylester, gelcoat,
or resin in which
the styrene
monomer is a
reactive monomer
for the resin.
VOC Limit
Applies To




Monomer VOC
Limit
(Wt% monomer
VOC in material
unless noted
otherwise)
Work and
Equipment
Practices



Allows atomized spraying, but requires use of higher efficiency
spray methods (e.g., HVLP, airless, air assisted airless).
No monomer VOC content limits on materials.
VOC materials used for cleanup must be collected in a closed
container.





VI.    Recommended Control Options

       We are recommending that this CTG covers the following operations:

   •   Open molding resin and gel coat operations (these include pigmented gel coat,
       clear gel coat, production resin, tooling gel coat, and tooling resin);

   •   Resin and gel coat mixing operations; and

   •   Resin and gel coat application equipment cleaning operations.
      Based on a review of the 2001 NESHAP, and the current State and local
requirements discussed above, we are recommending monomer VOC content limits
and alternative monomer VOC emission rate limits for resin and gel coats used in open
molding operations.  The monomer VOC content limits are paired with specific
methods (either atomized or non-atomized) for resin application.  In addition, we are
recommending a non-monomer VOC content limit for resins and gel coats used in open
molding operations.  We are also recommending work practices to reduce VOC
emissions from resin and gel coat mixing containers, and VOC content and vapor
pressure limits for cleaning materials. Our recommendations are described in more
detail below.
A.
Recommended VOC Limits for Gel Coats and Resins
      We are recommending monomer VOC content limits and alternative monomer
VOC emission rate limits for open molding operations. Our recommended monomer
VOC content and emission rate limits are based on the 2001 NESHAP for boat
manufacturing. As previously discussed in section IV.B of this CTG, styrene and MMA,
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which are the primary VOC emitted from resins and gel coats used in fiberglass boat, are
the only monomer VOC we have identified in these resin and gel coat materials. Because
styrene and MMA are also the primary HAP emitted by this industry, the HAP limits in
the 2001 NESHAP are equally effective in reducing monomer VOC emissions from the
resins and gel coats used in fiberglass boat manufacturing. As mentioned above, the
2001 NESHAP limits are more stringent than the limits provided in other Federal, State,
or local actions for the control of monomer VOC emissions from fiberglass boat
manufacturing. Based on the implementation of the NESHAP limits by all major source
fiberglass boat manufacturers, the general availability of the resins and gel coats that
meet the 2001 NESHAP limits, and the shift of the fiberglass boat manufacturing
industry (including area source fiberglass boat manufacturers) to non-atomized resin
application  methods, we believe that the monomer VOC limits recommended in this CTG
are technically and economically feasible for fiberglass boat manufacturers in ozone non-
attainment areas.

      Further, as previously mentioned, resins and gel coats used in fiberglass boat
manufacturing may also contain non-monomer VOC,  and they constitute less than 5
percent of the total VOC in all resins and gel coats and usually comprise less than 1
percent of each resin or gel coat, by weight.  Accordingly, we are also recommending a
non-monomer VOC content limit of no more than 5 percent by weight of the resin or gel
coat. This recommended limit on non-monomer VOC is in addition to the separate
monomer VOC limits being recommended for resin and gel coat. Based on our
recommendation, if the non-monomer VOC content of a resin or gel  coat exceeds 5
percent, then the excess non-monomer VOC over 5 percent would be counted toward the
monomer VOC content. For example,  if a resin contains  6 percent non-monomer VOC
and 34 percent monomer VOC, then 1 percent (the amount in excess of 5 percent) of the
non-monomer VOC would be counted  as a monomer VOC, and  the resin would be
considered as having a monomer VOC content of 35 percent.
             We recommend that the monomer VOC content of resin and gel coat
materials be determined using SCAQMD Method 312-91, Determination of Percent
Monomer in Polyester Resins, revised April 1996. In addition, we recommend that
manufacturer's formulation data be accepted as an alternative to this method.  If there is a
disagreement between manufacturer's formulation data and the results of a subsequent
test, we recommend that States use the test method results unless the facility can make a
demonstration to the States' satisfaction that the manufacturer's formulation data are
correct.The recommended monomer and non-monomer VOC limits in this CTG do not
apply to closed molding operations that meet the same definition of closed molding that
is found in the 2001 NESHAP. We recommend that closed molding operations that do
not meet this definition, such as vacuum bagging  operations, meet the monomer and non-
monomer VOC limits for open molding operations. That definition of closed molding is
as follows:

       "Closed molding means any molding process in which pressure is used to
       distribute the resin through the reinforcing fabric placed between two mold
       surfaces to either saturate the fabric or fill the mold cavity. The pressure may be
                                                                             24

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       clamping pressure, fluid pressure, atmospheric pressure, or vacuum pressure used
       either alone or in combination. The mold surfaces may be rigid or flexible. Closed
       molding includes, but is not limited to, compression molding with sheet molding
       compound, infusion molding, resin injection molding (RIM), vacuum assisted
       resin transfer molding (VARTM), resin transfer molding (RTM), and vacuum-
       assisted compression molding. Processes in which a closed mold is used only to
       compact saturated fabric or remove air or excess resin from the fabric (such as in
       vacuum bagging), are not considered closed molding. Open molding steps, such
       as application of a gel coat or skin coat layer by conventional open molding prior
       to a closed molding process, are also not closed molding."-"

       Consistent with the framework established in the NESHAP, we are
recommending that the recommended open  molding monomer and non-monomer VOC
limits described above not be applied to the following three types of materials at
fiberglass boat manufacturing facilities.  We are making this recommendation because
the following three materials must be formulated to meet specific performance
requirements, making it infeasible to reduce monomer and non-monomer VOC contents
below their existing levels. We are making different recommendations for the materials
identified below, and those recommendations are noted below:

       (1)  Production resins (including  skin coat resins) that must meet specifications
for use in military vessels or must be approved by the U.S. Coast Guard for use in the
construction of lifeboats, rescue boats, and other life-saving appliances approved under
46 CFR subchapter Q, or the construction of small passenger vessels regulated by 46
CFR subchapter T. Production resins that meet these criteria can still be applied with
nonatomizing resin application equipment, and we are recommending this as a control
option for these resins

       (2)  Production and tooling resins, and pigmented, clear, and tooling  gel coat used
for part or mold repair and touch up.  We recommend that the total resin and gel coat
materials that meet these criteria not exceed 1 percent by weight of all resin  and gel coat
used at a facility on a 12-month rolling-average basis.

       (3)  Pure, 100-percent vinylester resin used for skin coats. We recommend that
the monomer and non-monomer VOC limits not be applied to pure, 100-percent
vinylester resin used for skin coats.  We  still recommend these monomer and non-
monomer VOC limits for blends of vinylester and polyester resins used for skin coats.
Pure, 100-percent vinylester resin used for skin coats can be applied with nonatomizing
resin application equipment, and we recommend this as a control option for this type of
resin. We also recommend that the total amount of resin materials meeting this criteria
not exceed  5 percent by weight of all resin used at a facility on a 12-month rolling-
average basis.

       The CTG provides flexibility by recommending the same options for meeting
the monomer VOC limits as provided in the 2001 NESHAP for meeting the  HAP
1 40 CFR 63, subpart VVVV, §63.5779.


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emission limits. To meet the recommended open molding resin and gel coat limits, the
CTG recommends three options: (1) achieving the individual monomer VOC content
limit through the use of low-monomer VOC materials, either by using only low-
monomer VOC materials within a covered operation (as listed below in VIA), or by
averaging the monomer VOC contents for all materials used within an operation on a
weight-adjusted basis; (2) meeting the numerical monomer VOC  emission rate limits,
which would enable a facility to average emissions among different operations using
equations to estimate monomer VOC emission rates from each operation based on the
material and application method; or (3) using add-on controls to achieve a numerical
monomer VOC emission rate that is determined for each facility based on the mix of
application methods and materials used at that facility.

       The emission reductions that are achieved using the emissions averaging option
(Option 2) and the add-on control option (Option 3) are equivalent to the emission
reductions that are achieved by meeting the monomer VOC content limits (Option 1).
Options 2 and 3 use emission factor equations to convert the monomer VOC content
limits in Option 1 into equivalent monomer VOC emission rates that a facility would
otherwise achieve by using the low-monomer VOC materials for  specific application
methods and operations.

       A facility could use emission averaging (Option 2) or add-on controls (Option 3)
for all open molding operations or only for some of the operations.  Operations that a
facility decides not to include in Options 2 or 3 would use Option 1. For filled resins,
which are discussed in more detail in section VI. B, the CTG includes an adjustment
factor that would allow filled resins to use any of the three options recommended above.

       We are recommending that all three of these options be included in what States
determine constitutes RACT for VOC emissions from these operations. That is, we are
recommending that States not include just one option and exclude the other two. All
three options are recommended to be included, together, so as to provide flexibility to
facilities as they reduce their VOC emissions in response to State RACT determinations.
Our recommendations, as described above, are consistent with the approach and
flexibility we provided in the 2001 NESHAP for Boat Manufacturing.

       We are also recommending that State RACT determinations allow facilities to use
a combination of all three options at a single facility. For example, a facility could use
emissions averaging (Option 2) for only a subset of materials and activities and Option 1
for the rest of the materials and activities at the facility.  Our recommendations, as
described above, are consistent with the approach and flexibility we provided in the 2001
NESHAP for Boat Manufacturing.

 1.     Compliant Materials Option

       Under this option, facilities would use resins and gel coats that meet the
applicable recommended monomer VOC  content limits in Table 3 of this CTG and the
non-monomer VOC content limit of 5 percent.  We recommend that the applicable limits
be considered met if all materials of a certain type (e.g., production resin, pigmented gel
                                                                              26

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coat) meet the applicable monomer and non-monomer VOC content limits for a specific
application method.

Table 3. Compliant Materials Monomer VOC Content Recommendations for Open
                          Molding Resin and Gel Coat.
For this material--
Production resin
Production resin
Pigmented gel coat
Clear gel coat
Tooling resin
Tooling resin
Tooling gel coat
And this application method
Atomized (spray)
Nonatomized
Any method
Any method
Atomized
Nonatomized
Any method
This weighted average
monomer VOC content
(weight percent) limit is
recommended —
28
35
33
48
30
39
40
       Alternatively, the applicable recommended limits in Table 3 above would be
considered met if all materials of a certain type meet the applicable monomer VOC
content limit for a specific application method on a weighted-average basis, and each
resin and gel coat did not contain more than 5 percent non-monomer VOC. The
weighted-average monomer VOC content would be determined based on a 12-month
rolling average.  A facility would use Equation 1 to determine weighted-average
monomer VOC content for a particular open molding resin or gel coat material.

       Equation 1 :
             Weighted Average Monomer VOC Content =
Where:
2.
  Mi =      mass of open molding resin or gel coat i used in the past 12 months
            in an operation, megagrams.

VOQ =     Monomer VOC content, by weight percent, of open molding resin
            or gel coat i used in the past 12 months in an operation.

    n =      number of different open molding resins or gel  coats used in the
            past 12 months in an operation.

Emissions Averaging Option
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       Under this option, monomer VOC emissions from the open molding resin and gel
coat operations that a facility chooses to include in this emission average option would
meet a facility-specific monomer VOC mass emission limit (12-month rolling average)
that is determined using Equation 2.  All resins and gel coats included in this option
would also need to meet the recommended non-monomer VOC content limit of 5 percent.

       Equation 2:

Monomer VOC Limit = 46(MR) + 159(MpG) + 291(McG) + 54(MjR) + 214(MTG)

Where:

       Monomer VOC Limit=      total allowable monomer VOC that can be emitted
                                 from the open molding operations included in the
                                 average, kilograms per 12-month period.

        MR =       mass of production resin used in the past 12 months, excluding any
                    materials that are exempt, megagrams.

                    mass of pigmented gel coat used in the past 12 months, excluding
                    any materials that are exempt, megagrams.

                    mass of clear gel coat used in the past 12 months, excluding any
                    materials that are exempt, megagrams.

       MTR =       mass of tooling resin used in the past 12 months, excluding any
                    materials that are exempt, megagrams.

       MTG =       mass of tooling gel coat used in the past 12 months, excluding any
                    materials that are exempt, megagrams.

       The numerical coefficients associated with  each term on the right hand side of
Equation 2 are the allowable monomer VOC emission rate for that particular material in
units of kg/Mg of material used.

       For those materials that are not included in  the emissions average, the facility
would resort to one of the other two recommended options for limiting monomer and
non-monomer VOC emissions from resins and gel  coats.

       We recommend that the emissions average  be calculated on a 12-month rolling-
average basis  and determined  at the end of every month (12 times per year).  We further
recommend that at the end of the first 12-month averaging period and at the end of every
subsequent month, a facility use Equation 3 to show that the monomer VOC emissions
from the operations included in the average do not exceed the emission limit calculated
using Equation 2 for the same 12-month period. (A facility would include in Equations 2
and 3 the terms for only those operations and materials included in the average.)
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      Equation 3:

Monomer VOC emissions  =  (PVR)(MR) + (PVpG)(MpG) + (PVCG)(MCG) +

                     (PVTR)(MTR) + (PVTGXMTG)

Where:

Monomer VOC emissions = Monomer VOC emissions calculated using the monomer
                     VOC emission equations for each operation included in the
                     average, kilograms.

      PVR        =  Weighted-average monomer VOC emission rate for production
                     resin used in the past 12 months, kilograms per megagram.

      MR        =  Mass of production resin used in the past 12 months,
                     megagram s.

      PVpG      =  Weighted-average monomer VOC emission rate for pigmented
                     gel coat used in the past 12 months, kilograms per megagram.

                  =  Mass of pigmented gel coat used in the past 12 months,
                     megagram s.

                  =  Weighted-average monomer VOC emission rate for clear gel
                     coat used in the past 12 months, kilograms per megagram.

                  =  Mass of clear gel coat used in the past 12 months, megagrams.

       PVpR     =  Weighted-average monomer VOC emission rate for tooling
                     resin used in the past 12 months, kilograms per megagram.

        MTR     =  Mass of tooling resin used in the past 12 months, megagrams.

      PVjG      =  Weighted-average monomer VOC emission rate for tooling gel
                     coat used in the past 12 months, kilograms per megagram.

      MTG       =  Mass of tooling gel coat used in the past 12 months,
                     megagrams.

      For purposes of Equation 3, a facility would use Equation 4 to compute the
weighted-average monomer VOC emission rate for the previous 12 months  for each open
molding resin and gel coat operation included in the average.

      Equation 4:
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            I (
     PV   -.£
     *- y OP —
Where:
                   weighted-average monomer VOC emission rate for each open
                   molding operation (PVR, PVpQ, PVcG, PVjR, and PVjQ)
                   included in the average, kilograms of monomer VOC per megagram
                   of material applied.

         Mi =      mass of resin or gel coat i used within an operation in the past 12
                   months, megagrams.

          n =      number of different open molding resins and gel coats used within
                   an operation in the past 12 months.

        PVj =      the monomer VOC emission rate for resin or gel coat i used within
                   an operation in the past 12 months, kilograms of monomer VOC per
                   megagram of material applied. Use the equations in Table 4 to
                   compute PV;.

          Table 4. Monomer VOC Emission Rate Formulas for Open Molding
                                  Operations1*
For this material ...
1 . Production resin,
tooling resin




and this application method...
a. Atomized
b. Atomized, plus vacuum
bagging with roll-out
c. Atomized, plus vacuum
bagging without roll-out
d. Nonatomized
e. Nonatomized, plus vacuum
bagging with roll-out
f. Nonatomized, plus vacuum
bagging without roll-out
Use this formula to calculate
the monomer VOC emission
rate...
0.014 x (Resin VOC%)2.425
0.01185 x (Resin VOC%)2.425
0.00945 x (Resin VOC%)2.425
0.014 x (Resin VOC%)2.275
0.01 10 x (Resin VOC%)2.275
0.0076 x (Resin VOC%)2.275
k The formulae in this table were developed from EPA and industry-sponsored measurements of VOC
emissions from resin and gel coat used in open molding.


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 2. Pigmented gel     All methods                   0.445 x (Gel coat VOC%)l-675
 coat, clear gel coat,
 tooling gel coat
       The formulas in Table 4 calculate monomer VOC emission rates in kilograms of
monomer VOC per megagram of resin or gel coat applied.  The formulas for vacuum
bagging with roll-out are applicable when a facility rolls out the applied resin and fabric
prior to applying the vacuum bagging materials.  The formulas for vacuum bagging
without roll-out are applicable when a facility applies the vacuum bagging materials
immediately after resin application without rolling out the resin and fabric. VOC% =
monomer VOC content as supplied, expressed as a weight-percent value between 0 and
100 percent.

3.      Add-on Control Option

       If product performance requirements or other needs dictate the use of higher-
monomer VOC materials than those that would meet the recommended emission limits in
Table 3, a facility could choose to use add-on control equipment to meet the emission
limit determined by Equation 2.  However, instead of using the mass of each material
used over the past 12 months in Equation 2, the facility would use the mass of each
material used during the control device performance test in Equation 2 to determine the
emission limit  (in kg of monomer VOC) that is applicable during the test.  If the
measured emissions at the outlet of the control device (in kg of monomer VOC) are less
than the emission limit, then the facility would be considered to have achieved the
emission limit. We recommend that, during the test, the facility monitor and record
relevant control device and capture system operating parameters and use the recorded
values to establish operating limits for those parameters. We recommend that the facility
monitor the operating parameters for the control device  and emission capture system and
maintain the parameters within the established operating limits. All resins and gel coats
used in these controlled operations would also need to meet the recommended non-
monomer VOC content limit of 5 percent.

B.     Recommended Option for Filled Resins

       Some facilities use resins to which fillers  are added to achieve certain physical
properties, particularly for building molds. The resins to which the filler is added have
higher initial monomer VOC content than standard production or tooling resins, but the
addition of the filler lowers the monomer VOC emission rate from the filled resin. We
recommend the use of the following equation to adjust the emission rate for filled resins
under all three  options recommended above for limiting monomer VOC emissions from
resins and gel coats. If a facility is using a filled production resin or filled tooling resin, it
would calculate the emission rate for the filled material  on an as-applied basis using
Equation 5.

       Equation 5:
                                                                               31

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                             F     u
                                            100

Where:

       PVp =      The as-applied monomer VOC emission rate for the filled
                   production resin or tooling resin, kilograms monomer VOC per
                   megagram of filled material.

       PVU =      The monomer VOC emission rate for the neat (unfilled) resin,
                   before filler is added, as calculated using the formulas in Table 4 of
                   this CTG.

       % Filler =    The weight-percent of filler in the as-applied filled resin system.
       If the filled resin is used as a production resin, we recommend that the value of
PVp calculated by Equation 5 not exceed 46 kilograms of monomer VOC per megagram
of filled resin applied.  If the filled resin is used as a tooling resin, we recommend that the
value of PVp calculated by Equation 5 not exceed 54 kilograms of monomer VOC per
megagram of filled resin applied. If the facility is including a filled resin in the emissions
averaging procedure, we recommend that the facility use the value of PVp calculated
using Equation 5 for the value of PV; in Equation 4 of this CTG.  All filled resins would
also need to meet the recommended non-monomer VOC content limit of 5 percent, based
on the unfilled resin.

C.     Work Practices for Resin and Gel Coat Mixing Containers

       In addition to the recommended monomer and non-monomer VOC limits for gel
coats and resins described above, this CTG recommends that all resin and gel coat mixing
containers with a capacity equal to or greater than 208 liters (55 gallons), including those
used for on-site mixing of putties and polyputties, have a cover with no visible gaps in
place at all times. We do not recommend the use of covers for smaller containers
because they are typically only used for small hand application operations that require an
open container.  Also, this work practice would not apply when material is being
manually added to or removed from a container, or when mixing  or pumping equipment
is being placed in or removed from a container. Although monomer and non-monomer
VOC emission reductions achieved by implementing this work practice may not be
quantifiable, we have concluded that they are beneficial to the overall goal of reducing
VOC emissions.

D.     VOC Content and Vapor Pressure Limits for Cleaning Materials

       Cleaning solvents used to remove resin and gel coat residue from application
equipment are a potential source of significant VOC emissions. However, low-VOC and
low vapor pressure cleaning materials that can be used for cleaning boat manufacturing
application equipment are readily available. These materials include aqueous emulsifiers
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that have very low VOC contents, and also organic solvents, such as dibasic esters
(DBE), that have very low vapor pressures. Therefore, we are recommending that VOC
cleaning solvents for routine application equipment cleaning contain no more than 5
percent VOC, by weight, or have a composite vapor pressure of no more than 0.50 mm
Hg at 68 °F.

      These recommended limits for cleaning materials are based on the properties of
water-based emulsifiers and dibasic esters that are used as alternatives to conventional
cleaning solvents, and are the basis for the equipment cleaning requirements in the 2001
NESHAP for Boat Manufacturing. Therefore, the same cleaning materials used to
comply with the 2001 NESHAP will meet the VOC content and vapor pressure limits
recommended in this CTG for cleaning materials. Based on the implementation of these
measures by all major source fiberglass boat manufacturers, we believe that these control
measures are technically and economically feasible for reducing VOC emissions from
these cleaning materials and have therefore included them as  our recommendations in the
CTG.

      Occasionally through operator error or equipment malfunctions, resin or gel coat
is accidentally allowed to cure inside  application equipment.  To remove the cured resin
or gel coat, the equipment is typically soaked in a container of methylene chloride to
dissolve the cured material.  Boat manufacturing facilities usually maintain a small
amount (e.g., a few gallons) of methyl ene chloride on site for these situations.  Methyl ene
chloride is not a VOC. We recommend that only non-VOC solvents be used to remove
cured resin and gel coat from application equipment.

VII.  Cost Effectiveness  of Recommended Control Options

      Based on the 2002 NEI database, we estimate that there are 223 fiberglass boat
manufacturing facilities in the U.S. Using the April 2004 ozone nonattainment
designations, 91 of these facilities are in ozone nonattainment areas.  Based on the 2002
NEI VOC emissions data, we estimated that 67 of the 91 facilities in ozone
nonattainment areas emitted VOC at or above the recommended 6.8-kg/day (15-lb/day)
VOC emissions applicability threshold. These 67 facilities, in aggregate, emit about
1,452 Megagrams per year  (Mg/yr) (1,601 tons per year (tpy)) of VOC per year, or an
average of about 22 Mg/yr (24 tpy) of VOC per facility.

      The CTG recommends the use of low-VOC content (monomer and non-monomer
VOC) resin and gel coats with specified application methods. The CTG recommends the
use of covers on mixing containers to further reduce VOC emissions from gel coats and
resins. The CTG also recommends the use of low-VOC and low vapor pressure cleaning
materials. Because the recommendations in this CTG are based on the 2001 NESHAP
for boat manufacturing, those facilities that are major sources of HAP are already
complying with the 2001 NESHAP and have already adopted these control measures.
Therefore, we do not anticipate additional VOC emission reductions from these major
source facilities.
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       Because the 2001 NESHAP does not apply to area sources (i.e. sources that are
not major sources of HAP), area source fiberglass boat manufacturing facilities are not
currently required to implement the measures provided in the 2001 NESHAP and
recommended in the CTG.  We estimate that 23 area source fiberglass boat
manufacturing facilities are located in ozone nonattainment areas and meet the
applicability threshold recommended in the CTG, and that these facilities emit, in
aggregate 104 Mg/yr (115 tpy) of VOC.  We estimate that implementation of the
recommended measures in the CTG would reduce VOC emissions at these 23 facilities
by about 37 Mg/yr (40 tpy).

       For implementing the 2001 NESHAP, the EPA estimated a cost of $3,600 per ton
of HAP reduced, in 2001 dollars, or about $4,200 in 2007 dollars. Nearly all of the HAP
that are reduced by the NESHAP are styrene and MMA, and styrene and MMA also
account for nearly all of the VOC emitted from the processes addressed by the
recommendations in this CTG. Therefore, we expect that the cost to reduce HAP and
VOC are nearly equal.

       However, we expect that the cost of reducing VOC through the measures
recommended in this CTG would be substantially lower than the cost of reducing HAP
through the 2001 NESHAP for several reasons. First, the NESHAP is now fully
implemented at major sources of HAP, and resin, gel coat, and cleaning  materials that are
compliant with the 2001 NESHAP are readily available to all sizes of facilities. Second,
the industry has experienced a shift to non-atomized resin application methods that are
required to comply with the 2001 NESHAP. This shift has occurred at all sizes of
facilities because of the productivity and economic benefits of using non-atomizing
methods over conventional atomizing methods. Therefore, with respect to those facilities
that are not subject to the 2001 NESHAP, we expect that most, if not all, are already
using the materials and methods recommended by this CTG. We therefore expect that
these facilities would incur little,  if any,  increased costs if required by a  State RACT rule
to implement the approaches recommended in this CTG.  We estimate that the total
annual cost for the 23 facilities to implement the recommended measures in this CTG
would be substantially less than $168,000 in 2007 dollars.
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VIII.  References

Project Summary. Assessment of VOC Emissions from Fiberglass Boat Manufacturing.
Publication No. EPA/600/S2-90/019. U.S. Environmental Protection Agency, Research
Triangle Park, NC. June 1990.

40 CFR Part 63, Subpart VWV - National Emission Standards for Hazardous Air
Pollutants for Boat Manufacturing. §§63.5680 - 63.5776.

Economic Impact Analysis of the Boat Manufacturing NESHAP. U.S. EPA Office of Air
Quality Planning and Standards. Research Triangle Park, NC 27711. EPA Publication
No. EPA/452/R-01-011.  June 2001.

Bay Area (California) Air Quality Management District Regulation  8, Organic
Compounds, Rule 50, Polyester Resin Operations. Adopted June 15, 1994.

San Diego (California) Air Pollution Control District Rule 67-12. Polyester Resin
Operations. Am ended May 15,1996.

Santa Barbara (California) Air Pollution Control District Rule 349.  Polyester Resin
Operations. Adopted April 27,1993.

South Coast (California) Air Quality Management District Regulation XI, Source
Specific Standards, Rule 1162, Polyester Resin Operations.  Amended July  8, 2005.

South Coast (California) Air Quality Management District Method 312-91,
Determination of Percent Monomer in Polyester Resins, revised April 1996

Code of Maryland Administrative Regulations (COMAR) 26.11.19.26. Control of
Volatile Organic Compound Emissions from Reinforced Plastic Manufacturing.
Approved as part of Maryland SIP on August 19, 1999.

Puget Sound (Washington) Clean Air Agency, Regulation 2, Section 3.08, Polyester,
Vinylester, Gelcoat, and Resin Operations. Revised December 9, 1993.

Indiana Administrative Code, 326 IAC 8-1-6. Volatile Organic Compound Rules; New
facilities, general reduction requirements. Amended May 26, 2006.

Illinois Rule 218, Subpart CC. Organic Material Emission Standards and Limitations for
the Chicago Area. Subpart CC: Polyester Resin Product Manufacturing Process.
Effective January 24, 1994.
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