P.1 

OAR Box 1392 

Prepped by Ollie Stewart 

Document Number: 

134) ll-A-9 

Docket Number: 

A-94-52 

Printed 7/7/2008 9:45:59 AM Sheet 134 of 136 
P.2 

&EPA 

United Slates 

Environmental Protection 

Agency 

EPA-600/R-97-0l8;A"94-52 

3T-A-<7 

March 1997 

Research and 

Development 

EVALUATION OF POLLUTION PREVENTION 

TECHNIQUES TO REDUCE STYRENE EMISSIONS 

FROM OPEN CONTACT MOLDING PROCESSES ,. 

Volume I, Final Report , -"" 

Prepared for 

Office of Air Quality Planning and Standards 

Prepared by 

National Risk Management 

Research Laboratory 

Research Triangle Park, NC 27711 
-EJL 

FOREWORD 

The U.S. Environmental Protection Agency is charged by Congress with protecting the Nation's land, air, and water resources. Under a mandate of national • 

environmental laws, the Agency strives to formulate and implement actions leading to a compatible balance between human activities and the ability of natural 

systems to support and nurture life. To meet this mandate, EPA's research 

program is providing data and technical support for solving environmental problems today and building a science knowledge base necessary to manage our ecological resources wisely, understand how pollutants affect our health, and prevent or reduce environmental risks in the future. 

The National Risk Management Research Laboratory is the Agency's center for 

investigation of technological and management approaches for reducing risks 

from threats to human health and the environment. The focus of the Laboratory's 

research program is on methods for the prevention and control of pollution to air. 

Land, water, and subsurface resources; protection of water quality in public water 

systems; remediation of contaminated sites and groundwater; and prevention and 

control of indoor air pollution. The goal of this research effort is to catalyze 

development and implementation of innovative, cost-effective environmental 

technologies; develop scientific and engineering information needed by EPA to 

support regulatory and policy decisions; and provide technical support and information transfer to ensure effective implementation of environmental regulations 

and strategies. 

This publication has been produced as part of the Laboratory's strategic longterm research plan. It is published and made available by EPA's Office of Research and Development to assist the user community and to link researchers 

with their clients. 

E. Timothy Oppelt, Director 

National Risk Management Research Laboratory 

EPA REVIEW NOTICE 

This report has been peer and administratively reviewed by the U.S. Environmental 

Protection Agency, and approved for publication. Mention of trade names or 

commercial products does not constitute endorsement or recommendation for use. 

This document is available to the public through the National Technical Information 

Service, Springfield, Virginia 22161. 
P.4 

EPA-600/R-97-Ol8a 

March 1997 

Evaluation of Pollution Prevention 

Techniques to Reduce Styrene Emissions 

from Open Contact Molding Processes 

Volume I, Final Report 

By 

Emery J. Kong, Mark A. Bahner, Robert S. Wright, and C. Andrew Clayton 

Research Triangle Institute 

P.O. Box 12194 

Research Triangle Park, NC 27709 

EPA Cooperative Agreement CR 818419-03 

EPA Project Officer: Geddes Ramsey 

Air Pollution Prevention and Control Division 

National Risk Management Research Laboratory 

U.S. Environmental Protection Agency 

Research Triangle Park, NC 27711 

Prepared for 

U.S. Environmental Protection Agency 

Office of Research and Development 

Washington, DC 20460 
P.5 

Abstract 

Pollution prevention options to reduce styrene emissions, such as new materials and 

application equipment, are commercially available to the operators of open molding processes. 

However, information is needed about the percent reduction in emissions that is achievable with 

these options. 

To meet this need, several of these pollution prevention options were examined. Options 

examined were operator techniques, air flow velocities in the spraying area, gel coat and resin 

formulations, and application equipment. Styrene emission factors calculated from this test 

result were compared with the existing AP-42 emission factors for gel coat sprayup and resin 

applications. 

The study found that using controlled spraying (i.e., reducing overspray), low-styrene and 

styrene-suppressed materials, and nonatomizing application equipment can reduce styrene 

emissions from 11 to 52 percent. Facilities should investigate the applicability and feasibility of 

these pollution prevention options to reduce their styrene emissions. The calculated emission 

factors were from 1.6 to 2.5 times the mid-range AP-42 emission factors for the corresponding 

gel coat and resin application. These results indicate that facilities using existing AP-42 

emission factors to estimate emissions in open molding processes are likely to underestimate 

actual emissions. 

u 
P.6 

Contents 

Section Page 

Abstract ii 

Figures v 

Tables vi 

Acronyms and Abbreviations vii 

Conversion Table viii 

Acknowledgments ix 

Chapter 1 Introduction ; 1 

1.1 Background 1 

1.2 Objectives 2 

1.3 Approach 2 

1.4 Report Outline 2 

References 3 

Chapter 2 Experimental Test Design 4 

2.1 : Pilot Experiment .4 

2.2 Gel Coat Experiment : 5 

2.3 Resin Experiment 6 

Chapter 3 Facility and Experimental Setup 8 

3.1 Total Enclosure System 8 

3.2 Emission Sampling Location 8 

3.3 Experimental Setup 10 

3.3.1 FRP Mold 10 

3.3.2 Air Flow Baffle 10 

3.3.3 Glass Veil and Kraft Paper to Capture Overspray ..: 10 

3.3.4 Protective Equipment and Clothing for Operator 12 

3.4 Resin Property Testing Laboratory 12 

Chapter 4 Materials and Equipment : 13 

4.1 Properties of Gel Coat and Resin Materials 13 

4.2 Setting of Gel Coat and Resin Application Equipment 15 

4.3 Reinforcements 17 

Chapter 5 Determination of Emission Quantities 18 

5.1 Emission Measurement Method 18 

5.1.1 Determination of Styrene Concentrations in Exhausted Air 18 

5.1.2 Exhaust Air Flow Rate Measurement 21 

5.1.3 Emissions Determined by Emission Measurement Method 22 

5.2 Mass Balance Calculation Method Using Gravimetric Measurements 23 

in 
P.7 

Contents (continued) 

Section Page 

Chapter 6 Test Results and Discussion 27 

6.1 Distribution of Total Emissions During Application and Curing Stages 32 

6.2 Pilot Experiment Results 36 

6.3 Gel Coat Experiment Results 39 

6.4 Resin Experiment Results 43 

6.5 Comparison of Test Results with EPA AP-42 Emission Factors 49 

6.6 Comparison of Emission Measurement Method and Mass Balance 

Calculation Method 52 

6.6.1 Pure Styrene Evaporation Test 52 

6.6.2 Comparison of Emissions Measured by Two Test Methods 52 

Chapter 7 Data Quality Issues '. 58 

7.1 Summation of Project QA Activities 58 

7.2 RTI Internal Technical System Audit (TSA) Results 58 

7.3 EPA Performance Evaluation '... 59 

Chapter 8 Conclusions and Recommendations 60 

8.1 Conclusions 60 

8.2 Recommendations 61 

Appendixes (in Volume 2) 

A. A Category DI Quality Assurance Project Plan for the Evaluation of Pollution Prevention 

Techniques to Reduce Styrene Emissions from Open Contact Molding Processes 

B. Reichhold Standard Test Methods 

C. Verification and Intercomparison of Compressed Gas Calibration Standards 

D. Summary of Calibration Data, Calibration Error Tests, and Drift Checks 

E.. A Summary of Emission Measurements, Gravimetric Measurements, and Calculated 

Emission Quantities and Emission Factors for the Test 

F. Statistical Analyses of Test Results 

G. THC Analyzer Evaluation: Sampling Line Loss and Pressure Effect 

H. An RTI Technical System Audit Report 

I. EPA Performance Evaluation of Total Hydrocarbon Analyzer 

iv 
P.8 

Figures 

No, Page 

3-1 Side view of the Reichhold Chemicals spray booth and the experimental setup in 

a permanent total enclosure 9 

3-2 Sketch of a male mold 11 

5-1 Data recording sheet for mass balance calculation 26 

6-1 Distribution of emissions in the pilot and gel coat experiments 34 

6-2 Distribution of emissions in the resin experiment 35 

6-3 Typical emission concentration profiles for normal and controlled gel coat spraying .. 37 

6-4 Emission reductions observed in the pilot experiment 38 

6-5 Typical emission concentration profiles for regular and low-VOC gel coats 40 

6-6 . Typical emission concentration profiles for three types of gel coat spray guns 41 

6-7 Emission reductions observed in the gel coat experiment 42 

6-8 Emission concentration profiles observed for different resin application techniques 

and equipment 45 

6-9 Typical emission concentration profiles for various resin formulations 46 

6-10 Typical emission concentration profiles for low-profile, neat BPO, and modified 

BPO resins 47 

6-11 Emission reductions observed in the resin experiment: "controlled spraying" 

technique baseline 50 

6-12 Emission reductions observed in the resin experiment: "normal spraying" 

technique baseline 51 

6-13 Comparison of mass balance with EPA Method 25A emissions measurements, 

during pure (100 percent) styrene evaporation tests 54 

6-14 Comparison of emission measurement methods 56 
P.9 

Tables 

No. Page 

2-1 Test Runs for Pilot Experiment 5 

2-2 Test Runs for Gel Coat Experiment 6 

2-3 Test Runs for Resin Experiment .7 

4-1 Gel Coat Properties Measured at Reichhold 13 

4-2 Resin Properties Measured at Reichhold 14 

4-3 Summary of Gel Coat Equipment Setting 15 

4-4 Summary of Resin Application Equipment Setting 16 

6-1 Summary of Emission Measurements and Calculated Emission Factors 28 

6-2 Significance of Variables Affecting Total Styrene Emissions 31 

6-3 Distribution of Emissions in Pilot and Gel Coat Experiments 32 

6-4 Distribution of Emissions in Resin Experiment 33 

6-5 Summary of Emissions for Normal and Controlled Gel Coat Spraying 36 

6-6 Summary of Emissions for. Regular and Low-VOC Gel Coats 39 

6-7 Summary of Emissions for Resin Application Equipment 43 

6-8 Comparison of Emissions among Various Resin Application Equipment and Normal 

Spraying 44 

6-9 Summary of Emissions for Various Resin Formulations 48 

6-10 Comparison of EPA AP-42 Emission Factors and Test Results 49 

6-11 Comparison of Mass Balance Method and Emission Measurements for Pure 

Styrene Evaporation Tests ... . 53 

6-12 Comparison of Mass Balance Method and Emission Measurements 55 

6-13 Comparison of Mass Balance and Emission Measurement Test Results 57 

vi 
P.10 

-

• 

AAA 

ANOVA 

AP-42 

APPCD 

AS 

BPO 

CCP 

DCPD 

EPA 

FID 

FRP/C 

FS 

HVLP 

ISO 

MACT 

MEKP 

MMA 

MnTAP 

NDO 

NRMRL 

NV 

NVS 

ORTHO 

OSHA 

PFA 

QA 

QAPP 

THC 

TRI 

TSA 

VOC 

VS 

Acronyms and Abbreviations 

air-assisted airless 

analysis of variance 

EPA's Compilation of Air Pollutant Emissions Factors 

Air Pollution Prevention and Control Division 

available styrene 

benzoyl peroxide 

Cook Composites and Polymers 

dicyclopentadiene 

Environmental Protection Agency 

flame ionization detector 

fiberglass-reinforced plastics/composites 

full scale 

high volume, low pressure 

isophthalic acid 

maximum achievable control technology 

methyl ethyl ketone peroxide 

methyl methacrylate 

Minnesota Technical Assistance Program 

natural draft opening 

National Risk Management Research Laboratory 

nonvolatile 

non-vappr-suppressed 

orthophthalic 

Occupational Safety and Health Administration 

perfluoroalkoxy 

quality assurance 

Quality Assurance Project Plan 

total hydrocarbon 

Toxics Release Inventory 

technical system audit 

volatile organic compound 

vapor-suppressed 

vii 
P.11 

Conversion Table 

The U.S. Environmental Protection Agency policy is to express all measurements in Agency 

documents in metric units. In this report, however, to conform to industry convention, English 

units are used. Conversion factors from English to metric units are given below. 

English Unit Multiply by 

0.028314 

(°F-32)/1.8 

0.304 

0.0929 

3.79 

1.87 

0.454 

6.895 

0.907 

To Obtain 

mVmin 

°C 

m 

m

2 

L/min 

. mmHg 

kg 

kilopascal 

Mg 

ftVmin 

°F 

ft 

ft2 

gal/min 

in. H20 

lb 

psia 

ton 

vm 
P.12 

Acknowledgments 

During the research period, the authors received valuable information from Bob Lacovara 

of the Composites Fabricators Association and many representatives in the fiberglass-reinforced 

plastics/composites industry. The information helped the authors to design a focused test. 

The authors would like to acknowledge the invaluable support and assistance of the 

following organizations: 

• Reichhold Chemicals for providing a spray booth and all resin materials for the test and 

the laboratory support for gel coat and resin properties determination 

• Magnum Industries for providing equipment and an experienced operator (Charles Stard) 

to conduct the actual gel coat and resin application during the entire test period 

• Cook Composites and Polymers for providing all gel coat materials 

• PPG Industries, Inc., for providing all the fiberglass materials for the test. 

Without their generous support, the testing described in this report would not have been possible. 

IX 
P.13 

Chapter 1 

Introduction 

1.1 Background 

The open contact molding process is one of the most common production processes used 

by the fiberglass reinforced plastics/composites (FRP/C) and FRP boat building industry. This 

process is used to manufacture boats, bathtubs, shower stalls, truck cabs, body panels for 

recreational vehicles and trucks, swimming pools, etc. It is one of the FRP/C processes that 

consumes the most polyester resins. It also has the greatest potential of emitting styrene due to 

the spraying equipment used and the openness of the process. According to the 1990 Toxics 

Release Inventory (TRI) database, 10,600 tons of styrene were emitted from the FRP/C and boat 

building industries. More than 50 percent of the total styrene emissions was emitted from the 

open molding process. 

Styrene is emitted during the application stage when a catalyzed gel coat or resin is 

applied to the surface of an open mold. Styrene continues to be emitted from wet gel coat or 

resin during gelation and curing. The open contact molding process usually is conducted in a 

facility with ample ventilation to maintain the ambient styrene concentrations under the current 

Occupational Safety and Health Administration (OSHA) standard of 100 ppm. Therefore, 

styrene emissions from the open contact molding process are difficult to capture and control. 

The maximum achievable control technology (MACT) standards for the reinforced 

plastics/composites source category and boat building source category are scheduled to be 

promulgated by November 15, 1997, and November 15,2000, respectively. For some open 

contact molding processes, pollution prevention techniques could be used to reduce styrene 

emissions. These pollution prevention techniques include changing application equipment and 

environment and using different gel coat or resin formulations. Existing information indicates 

that using nonspraying equipment or low-emitting/high-transfer efficiency spray guns, such as 

air-assisted airless (AAA) or high-volume, low-pressure (HVLP) spray guns, can reduce 

emissions from the application stage. Gel coat and resin manufacturers also have developed 

different gel coat and resin formulations to reduce emissions. The effects of these pollution 

prevention techniques have not been compared systematically. 

Limited studies provide some indications that low-styrene resins can reduce emissions 

when compared to regular general-purpose resin. A demonstration project entitled Reducing 

Styrene Emissions in Fiber Reinforced Plastics Operations' was conducted by the Minnesota 

Technical Assistance Program in the early 1990s. The study found that styrene emissions from 

low-styrene resins were reduced by 25 to 45 percent compared to a conventional orthophthalic 

(ORTHO)-based general-purpose resin. However, the emissions measured from the simulated 

production trials were not a typical open molding process, and the emissions quantified may not 

directly apply to actual operations to estimate styrene emissions. A Finland research group2 

reports that low-styrene resin reduced total styrene evaporation by 30 to 60 percent compared to 
P.14 

standard resin. However, their test was conducted for hand layup operation under a laboratory 

hood, and the results cannot be applied to sprayup operations. 

1.2 Objectives 

This research project has three objectives. The first objective is to quantify and validate 

the effectiveness of several pollution prevention techniques, specifically operator techniques, air 

flow velocity in the spraying zone, different gel coat and resin formulations, and application 

equipment, on styrene emissions from the open contact molding process. The second objective is 

to compare a mass balance calculation method with an emission measurement method to quantify 

emissions. The third objective is to compare emission factors calculated from this test with the 

emission factors for gel coat sprayup and resin applications reported in the U.S. Environmental 

Protection Agency (EPA) AP-42 document3 to determine the accuracy of the AP-42 emission 

factors. The results of this study are to be presented to the FRP/C and boat building industries so 

that individual facilities can identify the most effective and practical pollution prevention 

techniques to reduce their styrene. emissions. 

1.3 Approach 

This test determined the styrene emission reduction from baseline conditions for several 

pollution prevention techniques on open contact molding processes. The baseline emissions .. 

were determined for a typical gel coat and a general purpose resin using a AAA spray gun under 

typical environmental and operating conditions. Pollution prevention techniques were evaluated 

for gel coat and resin applications under the same environmental conditions. The effectiveness 

of these pollution prevention techniques is determined by comparing total styrene emissions (in 

grams) and styrene emission factors, expressed as the weight percent of available styrene (% AS) 

and as mass per unit mold surface area (g/m2). The former unit (%AS) is the unit used in EPA' s 

AP-42 emission factors. The EPA Air Pollution Prevention and Control Division (APPCD) 

Category DI quality assurance.(QA) procedures were followed to ensure that the data quality is 

sufficient to evaluate the effectiveness of these materials and equipment. The QA project plan 

(QAPP) for this testing is included in Appendix A (Volume H). 

1.4 Report Outline 

This report in divided into two volumes. Volume I documents the planning, execution, 

and findings of the pollution prevention technique evaluation test. Chapter 2 presents the 

experimental design. Chapter 3 describes the facility and the setup for the testing. Chapter 4 

describes the testing procedures used to quantify emissions from the operation. Chapter 5 

presents the materials and equipment used in the testing. Chapters 6 and 7 present the results of 

the testing and the associated data quality issues, respectively. Chapter 8 summarizes the 

conclusions from the research and presents the recommendations to the industry. Volume H 

contains the appendixes to mis report detailed supporting documents that are related to data 

quality and emission measurement issues. 

% 
P.15 

References 

Minnesota Office of Waste Management. Reducing Styrene Emissions in Fiber 

Reinforced Plastics Operations. Minnesota Technical Assistance Program (MnTAP), 

Minneapolis, Minnesota, 1993. 

Saamamen, A.J., R.L Miemela, T.K. Blomqvist, and E.M. Nikander. Emission of 

Styrene During the Hand Lay-up Molding of Reinforced Polyester. Applied Occupation 

Environmental Hygiene, 6(9): 790-793, September 1991. 

U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards. 

Compilation of Air Pollutant Emission Factors (AP-42). Research Triangle Park, NC. 

p. 4.12-1, September 1988. 

3 

3 
P.16 

Chapter 2 

Experimental Test Design 

This testing included a pilot experiment, a gel coat experiment, and a resin experiment. 

From the pilot experiment, the linear air flow velocity in the spraying zone and the spraying 

technique were evaluated and a set of conditions was selected for the subsequent gel coat and 

resin experiments. The gel coat experiment examined two gel coat formulations with three 

pieces of gel coating equipment (i.e., spray guns). The resin experiment examined five resin 

formulations and three pieces of resin application equipment. Except for a styrene-suppressed 

resin with additional wax, the rest of the gel coat and resin formulations and application 

equipment selected for the testing are commercially available to the FRP/C and boat building 

industries. Each of the experiments is described in the following subsections. 

2.1 Pilot Experiment 

Before these formulations and equipment were examined, the effects on styrene emission 

of the air flow velocity in the spray zone and the spraying technique of the operator were 

evaluated in the pilot experiment. The pilot experiment was conducted by spraying a regular 

isophthalic acid (ISO)-based gel coat using a AAA spray gun. The gel coat was catalyzed with 

methyl ethyl ketone peroxide (MEKP). A low (40 to 50 ft/min) and a high (100 ft/min) air flow 

velocity in the spray zone were examined. Air velocities were measured by a hot-wire 

anemometer at several locations across the spraying zone. This range represents the low and 

high ends of air flow velocity found in an open molding area or in a spray boom. The spraying 

technique of the operator was evaluated by asking the operator to spray normally (without. 

consciously controlling the spray fan beyond the mold surface and flange) and in a controlled 

pattern. Controlled spraying was done by consciously minimizing overspray beyond the flange 

of the mold. The effects of spraying techniques were quantified by transfer efficiency, which is 

the percentage of gel coat material deposited on the mold right after application. Spraying 

techniques, shape of mold (male or female), and size of mold all affect the transfer efficiency of 

the material applied. 

The number of test runs for air flow velocity and spraying method are summarized as 

follows and presented in Table 2-1. 

A. Air flow velocity (as measured by a hot-wire anemometer across the spraying zone) 

A1. Low air flow velocity (30 to 50 ft/min) 

A2. High air flow velocity (90 to 120 ft/min) 

B. Spraying method 

M1. Normal technique without conscious control of overspray from flanges 

M2. Controlled spraying technique with more conscious control to reduce overspray 

4-
P.17 

Table 2-1. Test Runs for Pilot Experiment 

Ml-Normal technique 

M2-Controlled technique 

Al-Low air flow velocity 

3 

3 

A2-High air flow velocity 

3 

3 

The results were analyzed to determine whether there are any differences in styrene 

emissions resulting from different air flow velocities and spraying techniques. Following the 

pilot experiment, the low air flow velocity and controlled spraying technique were selected for 

the subsequent gel coat and resin experiments. 

2.2 Gel Coat Experiment 

The gel coat formulations selected were one regular ISO-based gel coat and a low-volatile 

organic chemical (VOC), isophthalic acid/neopentyl glycol (ISO/NPG®)-based gel coat. Cook 

Composites and Polymers (CCP) provided these two gel coats. For the purpose of this testing, 

both gel coats contained straight styrene without any methyl methacrylate (MMA). Typical gel 

coats contain only a low percentage of MMA while the styrene content may range from 35 to 50 

percent. This minor modification allowed the assumption that total emissions quantified were 

styrene emissions. A Reichhold Superox® 46709 MEKP catalyst was used and the catalyst ratios 

followed those suggested by CCP. 

The gel coat spraying equipment selected included: one AAA spray gun with external 

catalyst mixing, one HVLP spray gun with internal catalyst mixing, and one HVLP spray gun 

with external catalyst mixing. According to the Composites Fabricators Association's industry 

survey, the AAA external mixing spray gun is the major spray gun used by die industry; : 

therefore, it is treated as the baseline condition. The AAA spray gun was compared with the 

HVLP spray gun. The effects of internal and external catalyst mixing were evaluated for the 

HVLP spray guns. Magnum provided all three spray guns. A pump ratio of 20:1 was selected 

for the gel coat pump systems. The spray guns were compared at similar gel coat thicknesses 

(about 18 to 24 mil) sprayed on an FRP mold. 

The gel coat formulations and application equipment are denoted as follows: 

A'. Formulations 

GF1. Regular ISO-based gel coat (baseline condition) 

GF2. Low-VOC, ISO/NPG®-based gel coat 

B. Equipment 

GE1. AAA spray gun with external catalyst mixing (baseline condition) 

GE2. HVLP spray gun with internal catalyst mixing 

GE3. HVLP spray gun with external catalyst mixing. 

Table 2-2 shows the number of test runs for each of the gel coat formulation and 

equipment combinations in the gel coat experiment. 

5 
P.18 

Table 2-2. Test Runs for Gel Coat Experiment 

Formulation 

GF1 Regular gel coat 

GF2 Low-VOC gel coat 

Equipment type 

GEl-AAA(ext) 

3 

3 

GE2-HVLP(int) 

3 

3 

GE3-HVLP(ext) 

3 

3 

ext=External catalyst mixing. 

int=Internal catalyst mixing. 

2.3 Resin Experiment 

The resin experiment examined five resin formulations with a AAA spray gun and three 

pieces of application equipment with a regular low-profile resin. 

The resin formulations selected were one dicyclopentadiene (DCPD)-based low-profile 

resin catalyzed with MEKP, one DCPD-based low-styrene resin, one ORTHO-based styrenesuppressed resin, one DCPD-based resin catalyzed with benzoyl peroxide (BPO), and the same 

ORTHO-based styrene-suppressed resin with an additional wax content. All the resin 

formulations were sprayed by a AAA spray gun. Reichhold Chemicals, Inc., provided all resin 

formulations and catalysts. Reichhold's Superox® 46709 MEKP solution has 9 percent active 

oxygen. Reichhold's Superox® 46744 BPO catalyst is a 40 percent BPO dispersion in 

nonvolatile plasticizer that has 2.6 percent active oxygen. The catalyst ratios for each of the 

resins followed those suggested by Reichhold. 

The pieces of resin application equipment selected were one AAA spray gun with 

external catalyst mixing, a flow coater with internal catalyst mixing, and a pressure-fed roller 

with internal catalyst mixing. The AAA spray gun has a valve mat allows me operator to use 

either MEKP or BPO catalyst solution. The AAA external mixing spray gun is considered die 

baseline condition of me industry. The AAA spray gun was compared with omer nonspraying 

equipment (i.e., the flow coater and the pressure-fed roller). Magnum provided all the equipment 

for evaluation. A pump ratio of 11:1 was selected for the resin pump systems. The equipment 

was compared at similar resin laminate thicknesses (about 70 to 100 mil). Fiberglass roving was 

used for the AAA spray gun and 1.5-oz/ft2 chopped strand mat was used for me flow coater and 

•pressure-fed roller. Two layers of me chopped strand mat were used for nonspraying lamination; 

multiple passes of sprayup were used to give similar laminate thicknesses. 

Resin formulations and application equipment are denoted as follows: 

A. Formulations 

RF1. DCPD-based low-profile resin catalyzed with MEKP (baseline condition) 

RF2. DCPD-based low-styrene resin catalyzed with MEKP 

.RF3. ORTHO-based styrene-suppressed resin catalyzed witii MEKP 

tn 
P.19 

RF4. DCPD-based resin catalyzed with BPO 

RF5. Water-emulsified resin (included in the test plan but the manufacturer 

withdrew from the test) 

RF6. Same ORTHO-based styrene-suppressed resin (RF3) with an additional 

0.1 percent wax 

B. Equipment 

RE 1. AAA spray gun with external catalyst mixing (baseline condition) 

RE2. Flow coater with internal catalyst mixing 

RE3. Pressure-fed roller with internal catalyst ihixing 

RE4. Same AAA with external BPO catalyst mixing for the resin catalyzed with 

BPO 

Table 2-3 shows the number of test runs for the resin formulation and equipment 

examined in the resin experiment. 

Table 2-3. Test Runs for Resin Experiment 

Formulation 

RF1. DCPD-based low-profile 

resin with MEKP catalyst 

RF2. DCPD-based low-styrene 

resin with MEKP catalyst 

RF3. ORTHO-based styrenesuppressed resin with MEKP 

catalyst 

RF4. DCPD-based low-profile 

resin with BPO catalyst 

RF6. ORTHO-based styrenesuppressed resin + 0.1 % of wax 

with MEKP catalyst 

REl-AAA(ext) 

6 

3 

3 

NA 

3 

Equipment type 

RE2-flow 

coater(int) 

3 

NA 

NA 

NA 

NA 

RE3-pressurefed roller(int) 

3 

NA 

NA 

NA 

NA 

RE4-AAA (ext) 

for BPO resin 

NA 

NA 

• NA 

3 

NA 

ext=External catalyst mixing. 

int=Internal catalyst mixing. 

NA = Not included in the experiment. 

Note: RF5 is a water-emulsified resin that was not tested because the manufacturer withdrew from the test. 

Ir 
P.20 

Chapter 3 

Facility and Experimental Setup 

The evaluation test was conducted in an isolated spray booth in Reichhold Chemicals' 

physical testing laboratory, located in Research Triangle Park, North Carolina. This type of spray 

boom is commonly used in an FRP/C facility. Reichhold Chemicals' physical testing laboratory 

is used to perform testing for their resin users. It is not a production facility; therefore, the 

background VOC concentration can be minimized. 

3.1 Total Enclosure System 

The spray booth is situated in an enclosed room with a double door leading to the 

physical testing laboratory. The laboratory is air-conditioned; therefore, the room temperature 

and humidity were very stable during the entire period of testing. The stable conditions reduced 

the variability of temperature effect. Most facilities are not air-conditioned in the summer, 

however, they do have winter heating to maintain product quality. 

Figure 3-1 shows the side view of me spray booth. The room is 12 feet wide, 19 feet 

high, and 15 feet deep, which can be considered a permanent total enclosure. The double door 

measures 6 feet wide by 7 feet high, which can be considered the natural draft opening (NDO) to 

the enclosure. Inward linear air flow velocity at the door (i.e., NDO) during the testing was 

always above 200 ft/min. The spray booth and me enclosed room meet me criteria for a total 

enclosure as prescribed in EPA Method 204—Criteria for and Verification of a Permanent or 

Temporary Total Enclosure. Therefore, the emissions from the operations in the spray booth can 

be assumed 100 percent captured. 

The spray boom is 7 feet high, 11.5 feet wide, and 7.5 feet deep from me front edge to tiie 

filter bank. The filter bank is 6 feet high by 11 feet wide. The distance between the front edge of 

the spray booth to the double door is 4 feet 10 inches. The air-conditioned makeup air flows 

through the double door. The exhaust air flows through the filter bank at the end of the spray 

booth and is exhausted upward by a duct 34 inches in diameter. The exhaust flow rate from the 

spray booth averaged 8,670 ftVmin during the testing. 

3.2 Emission Sampling Location 

Emission measurements and exhaust air flow rate were monitored from the exhaust duct. 

The sampling location is 6 diameters downstream of the last bend as shown in Figure 3-1. EPA 

Methods 1 and 2 were used to determine the exhaust gas velocity and volumetric flow rate. EPA 

Method 25A was used to determine total gaseous organic emissions. The emission sampling 

procedures are outlined in Section 5.1. 
P.21 

19" 

7" 

o c Emission and air flow rate 

monitoring location 

2nd floor 

6'x11'(W) 

Filter 

7'6" 

7'x6" (W) 

Double door 

Floor scale 

Application equipment 

(placed outside the enclosure 

on a floor scale) 

Figure 3-1. Side view of the Reichhold Chemicals spray booth and the experimental 

setup in a permanent total enclosure (19'H x 12'W x 15'L). 

9 
P.22 

3.3 Experimental Setup 

3.3.1 FRP Mold 

Three identical FRP molds were used for this evaluation test. Figure 3-2 shows a sketch 

of the male FRP mold. The male mold has five exposed smooth surfaces similar to a rectangular 

box. The mold measures 2 feet high, 2.5 feet long, and 2 feet wide. A 2-inch wide flange 

surrounds the bottom of the mold for ease of part removal. The total surface area, including 

flange, equals 24.5 ft2 (2.28 m2). The mold is constructed of traditional reinforced plastics 

material to represent actual tooling material used by the industry. These empty molds weighed 

about 34 kg. The mold was placed on a turntable mounted on a cart with casters. The turntable 

allows the operator to spray on all mold surfaces by turning the mold and without moving his 

position to the downwind location. The cart allows easy transfer of the mold from a preparation 

area to the spray booth. 

3.3.2 Air Flow Baffle 

The exhaust flow rate from the spray booth could not be adjusted because the spray booth 

had a constant speed exhaust fan. Therefore, a baffle was used between the double door and the 

spraying zone to divert me air flow to the sides of the spray booth so that the air flow velocity in 

the spraying zone could be reduced. The 6.5-foot by 4-foot baffle was constructed from lattice 

board on a frame built from 2-inch by 4-inch studs. It has two additional pieces measuring 6.5 

feet by 2 feet on either side of the baffle. These two side pieces can swing open like a screen. 

Two layers of 15-mil-thick glass veil were attached to the centerpiece of the baffle to reduce the 

air flow velocity through the baffle. In the pilot experiment, the baffle was used to maintain the 

low air flow velocity and was removed for the high air flow velocity. Using this baffle, the linear 

air flow velocity in the spraying zone can be reduced from more than 100 ft/min to 40 ft/min. 

The baffle was used throughout the gel coat and resin experiments to maintain a low air velocity 

in die spraying zone. 

3.3.3 Glass Veil and Kraft Paper to Capture Overspray 

Gel coat and resin sprayup generate overspray. To account for the materials not adhered 

to the mold, glass veil was used on the filter bank and kraft paper was used on the ground surface 

and side walls to capture overspray. The veil is 15 mils thick of A-type glass with non-styrenesoluble binder. Two layers of the veil were used on the filter bank. The test results showed mat 

almost all airborne droplets were trapped on the first layer of veil. The kraft paper used for 

ground cover was 50# weight. These veil and kraft papers were replaced every test run so mat 

overspray for each test run could be accounted for accurately. 

10 

IO 
P.23 

2" flange surrounding 

the bottom of the mold 

to ease part removal 

Figure 3-2. Sketch of a male mold. 

11 

1 \ 
P.24 

3.3.4 Protective Equipment and Clothing for Operator 

The operator wore a respirator with activated carbon cartridges to protect him from 

exposure to styrene during the application stage of a test run. The operator also wore safety 

glasses at all times. In order to account for any materials that might come into contact with the 

operator, clean disposable gloves, coveralls, and shoecovers were used in each test mn. This 

protective gear was weighed before and after the test mn to determine the amount of materials on 

them. 

3.4 Resin Property Testing Laboratory 

Reichhold Chemicals has a resin property testing laboratory located in the same building 

as the spray booth. The laboratory has all the instrument and equipment necessary to determine 

the styrene contents and curing characteristics for the gel coat and resin formulations. Reichhold 

personnel followed their standard procedures to measure properties for every gel coat and resin 

formulation examined in the test. These Reichhold Standard Test Procedures are No. 18-001, 

Determination of Non-Volatile Content of Polyester Resins; No. 18-021, Determination of 

Brookfield Viscosity & Thixotropic Index of Polyester Resins; No. 18-501, Determination of 

Room Temperature Gel, Time to Peak, and Peak Exotherm Characteristics of Polymer Resin; 

and No. 18-152, Determination of Static Styrene Emissions for Compliance widi SCAQMD Rule 

1162. Copies of these Reichhold standard test procedures are provided in Appendix B 

(Volume n). 

12 

) 2-
P.25 

Chapter 4 

Materials and Equipment 

4.1 Properties of Gel Coat and Resin Materials 

The properties of the gel coats and resins were analyzed by Reichhold personnel in their 

laboratory using Reichhold standard test methods. These properties are shown in Table 4-1 for 

gel coats and Table 4-2 for resins. A large sample (about 200 g) was collected for each material 

when it was first used and a smaller sample (about 20 g) was collected when the material was last 

used. At the end of the testing, the large samples were analyzed for the listed properties and the 

small samples for percent nonvolatile (%NV). The final %NV measurement was to verify 

whether the material lost styrene over the test period or not. The results indicated that no 

noticeable styrene was lost from the container because proper procedures were used to minimize 

styrene evaporation loss. 

Generally, me measured properties were in agreement with the properties listed in the 

manufacturers' data sheets. However, major differences were found for me low-VOC gel coat, 

the low-styrene resin, and the BPO resin. At the same catalyst ratio, the measured cup gel time 

for the low-VOC gel coat (27 min) is longer than CCP's listed gel time (14-17 min). Measured 

gel time for low-styrene resin (30 min) is also longer than a typical gel time (15 min) listed in the 

Reichhold data sheet. The longer gel time might have an effect on total emissions because die 

wet surface had a longer time to emit styrene. 

Table 4-1. 

CCP product code (color) 

Density, ib/gal 

% NV, average (range) 

% Styrene (by difference) 

Viscosity, cps (LVF #4 @ 60 rpm) 

Thix index 

Catalyst Superox8 No. and type 

Catalyst ratio, weight % 

Cup gel time, min 

Total time to peak, min 

Peak exotherm, °F 

Rule 1162 static emissions, g/m2 

Gel Coat Properties Measured at Reichhold 

GFl Regular gel coat 

944-W-005SP (base white) 

10.6-10.9 

61.3(61.1:61.4) 

38.7 ' 

3,040 

6.1 

46709 MEKP 

1.8 

17 

35 

353 

133 

GF2 Low-VOC gel coat 

962-WA-196SP (pink) 

11.3-11.6 

74.6 (74.6-74.7) 

25.4 

2,970 

3.9 

46709 MEKP 

1.8 

27 

51 

251 

83 

13 

)3 
Reichhold's Polylite® No. 

Density, lb/gal 

% NV, average 

(range) 

% Styrene (by difference) 

Viscosity, cps (Brbokfield LVF 

#3 @ 6/60 rpm) 

Thix index 

Catalyst Superox® No. and type 

Catalyst ratio, weight % 

Cup gel time, min 

Total time to peak, min 

Peak exomerm, °F 

Rule 1162 static emissions, g/m2 

Table 4-2 

RF1 

Lowprofile 

33233-05 

9.0 

61.7 

(60.9-62.2) 

38.3 

585 

3.5 

46709 

MEKP 

1.5 

20 

31 

333 

69.0 

,. Resin Properties Measured at Reichholc 

RF2 

Lowstyrene 

33234-17 

9.2 

64.7 

(63.8-65.5) 

35.3 

421 

2.3 

46709 

MEKP 

1.4 

30 

40 

316 

73.6 

RF3 

Styrenesuppressed 

33099-08 

9.1 

56.5 

(56.5-56.6) 

43.5 

534 

2.6 

46709 

MEKP 

1.5 

17 

32 

309 

54.0 

RF6 

Styrenesuppressed* 

0.1% wax 

33099-08 

9.1 

56.7 

(56.7-56.7) 

43.3 

394 

2.5 

46709 

MEKP 

1.5 

17 

33 

318 

49.4 

1 

RF4 

Neat BPO 

33146-17 

9.1 

57.4 

(57.3-57.4) 

42.6 

163 

2.2 

46744 

BPO 

2.1 

(slow gel) 

30 

39 

231 

160.9 

RF4 (modified) 

BPO+0.5% fume 

silica as thickening 

agent 

33146-17 

9.1 

57.4 

(57.3-57.4) 

42.6 

386 

3.8 

46744 

BPO 

3.1 

(fast gel) 

17 

26 

277 

96.6 

ho 

0) 
P.27 

When the neat (unfilled) BPO resin was first used, it had a much longer gel time (30 min) 

than the listed gel time (12 min). Its viscosity was also low, so the resin did not stay on the mold 

until it cured. After two test runs on the neat BPO resin, a 0.5 weight percent pf fume silica was 

added to thicken the resin and tiie BPO catalyst ratio was increased from 2.1 to 3.1 percent to 

shorten the gel time. Two additional test mns were conducted for the modified BPO resin. The 

test results for neat BPO resin and modified BPO resin were analyzed separately. 

4.2 Setting of Gel Coat and Resin Application Equipment 

The application equipment was prepared for each test mn in a separate spray booth. An 

experienced operator from Magnum Industries operated the application equipment for the entire 

5-week period. He adjusted the setting on the equipment in the preparation area until a good 

spray pattern was acquired. Then the equipment was disconnected from the central compressedair line, moved to the spray booth where the test was conducted, and reattached to the central 

compressed-air line. The setting on the equipment was recorded after the application was 

completed. Tables 4-3 and 4-4 show the range of the setting for the gel coat and resin application 

equipment, respectively. Table 4-3 shows that the low-VOC gel coat required more air pressure 

and larger spray tips to achieve a spray pattern similar to the regular gel coat. 

Table 4-3. Summary of Gel Coat Equipment Setting 

Equipment type 

Magnum model No. 

Pump ratio 

Type of gel coat 

Air supply pressure, psi 

Catalyst atomizing 

pressure, psi 

Spray tip No. 

Catalyst ratio setting, 

volume % 

Deliver rate, g/min 

Deliver rate, gal/min 

GE1-AAA (external 

catalyst mixing) 

ATG-3500 

20:1 

GFl 

Regular 

42-44 

26 

418 

2.1 

784-794 

0.16 

GF2 

Low-VOC 

52-60 

26 

518/718 

2.1-2.4 

746-839 

0.14-0.16 

GE2-HVLP (internal 

catalyst mixing) > 

HVLPF-5500 

20:1 

GFl 

Regular 

38-45 

NA 

418 . 

2.1 

670-760 

0.14-0.16 

GF2 

Low-VOC 

60-68 

NA 

518/718 

2.1-2.4 

779-933 

0.15-0.18 

GE3-HVLP (external 

catalyst mixing) 

HVLPF-5500 

20:1 

GFl 

Regular 

42-44 

26 

418 

2.1 

780-809 

0.16-0.17 

GF2 

Low-VOC 

54-64 

26 

518/718 

2.1-2.4 

774-927 

0.15-0.18 

15 

1<S"~ 
Equipment type 

Magnum model No. 

Pump ratio 

Type of resin 

Air supply pressure, 

psi 

Catalyst atomizing 

pressure, psi 

Spray tip No. 

Catalyst ratio setting, 

volume % 

Deliver rate, g/min 

Deliver rate, gal/min 

Table 4-4. Summary of Resin Application Equipment Setting 

REl-AAA (external MEKP catalyst 

mixing) 

ATC-4000 

11:1 

RF1 

lowprofile 

37-39 

18-19 

443 

1.5-1.6 

2332-

2559 

0.57-0.63 

RF2 

lowstyrene 

37-38 

18 

443 

1.6 

2316-

2335 

0.56-0.56 

RF3 

styrenesuppress. 

37-41 

17-18 

443 

1.5-1.6 

2254-

2409 

0.55-0.58 

RF6 

styrenesuppress. 

+ wax 

36-38 

18-26 

443 

1.6 

2286-

2569 

0.55-0.62 

RE4-AAA (external 

BPO catalyst mixing) 

ATC-4000 

11:1 

RF4 

neat BPO 

26 

43-45 

443 

2.0-3.0 

2065-

2376 

0.50-0.58 

RF4 

BPO with 

thickener 

24-25 

41-43 

443 

3.5 

2205-2269 

0.53-0.55 

RE2-Flow 

coater 

(internal 

catalyst 

mixing) 

Flo-6000 

11:1 

RF1 

low-profile 

40-42 

NA 

#2 

1.5-1.6 

3388-3605 

0.83-0.88 

RE3-Pressurefed roller 

(internal 

catalyst 

mixing) 

MRD resin 

roller 

11:1 

RF1 

low-profile 

40-42 

NA 

NA 

1.6 

Not measured 

Not measured 
P.29 

4.3 Reinforcements 

PPG Industries, Inc., provided all the reinforcements for the testing. The HYBON® 700 

HTX roving material was used for resin sprayup and a GPM chopped strand mat (1.5 oz/ft2) was 

used for nonspraying resin lamination. The chopped strand mat was cut into proper sizes before 

the test so that the operator could apply the mat, piece by piece, on the mold surface. 

17 

IT-
P.30 

Chapter 5 

Determination of Emission Quantities 

Two separate test methods were used to quantify emissions from the test. The first test 

method was an emission measurement method that uses EPA Mediod 25A to determine a realtime, continuous emission concentration in the stack and EPA Methods 1 through 4 to determine 

the exhaust flow rate. Because the enclosed room with the spray booth met the criteria for a total 

enclosure, the emissions within the enclosed room could be assumed 100 percent captured. The 

emission quantities were calculated from the product of an average emission concentration and 

an average exhaust flow rate during a test run. 

The second test method was a mass balance calculation method using gravimetric 

measurements. This method measures the weights of all materials, overspray, mold, and part at 

the beginning and end of each test run. The difference between the total initial weight and the 

total final weight is considered the weight loss due to emissions. 

Before and during the test campaign, pure styrene evaporation tests were used to 

compare the emission quantities determined by these two test methods. This involved measuring 

weight loss due to evaporation from terry cloth towels soaked in pure styrene using a highprecision scale. The measured weight loss was compared with emissions determined by the 

emission measurement method. If the results are close, it implies that the emission measurement 

method was accurate. 

Both test mediods determine total emissions. Because these gel coat and resin materials 

contained only styrene monomer, the total emissions measured could be considered styrene 

emissions. Omer VOC emissions were excluded from the surrounding environment. The 

background (i.e., baseline) VOC concentration in the laboratory was measured before each test 

run and subtracted from the average emission concentration so the net increase in concentration 

could be attributed to the test. A test mn began when gel coat or resin application started and 

ended when curing was complete and the monitored concentration returned to the baseline 

concentration. Most of the test mns lasted from 60 to 90 minutes, depending on the time 

required for complete curing. Two test rans for the neat BPO resin were longer than 100 minutes 

because of unusually long curing time. 

5.1 Emission Measurement Method 

The emission measurement method determines styrene concentrations in the exhaust air 

and exhaust air flow rate, then uses these results to calculate total emissions during the test run. 

5.1.1 Determination of Styrene Concentrations in Exhausted Air 

Styrene emissions in the exhaust stack of the total enclosure were measured according to 

EPA Method 25A as given in Code of Federal Regulations, Chapter 40, Part 60. The 

18 

Ifc 
P.31 

measurements were made using a Ratfisch Instraments model RS55CA total hydrocarbon (THC) 

analyzer. This analyzer has a flame ionization detector (FID) that responds to hydrocarbons 

approximately in proportion to the number of carbon atoms entering the detector. The total 

hydrocarbon measurements can be attributed to the styrene emissions because the only 

hydrocarbon emission source was the gel coat or resin application and styrene is the only 

monomer used in the formulations. Measurements were made immediately before gel coat or 

resin application started to determine the levels of background hydrocarbons (e.g., natural 

methane and other trace VOCs) in ambient air. These background levels were subtracted from 

the levels measured during the test run. 

The THC analyzer was connected to the exhaust stack by a sampling line fabricated from 

a 12-foot length of 1/4-inch ID perfluoroalkoxy (PFA) Teflon tubing. The tubing was capped 

inside the exhaust stack. Eight holes were drilled in the tubing at various points across the 34-

inch diameter of the exhaust stack to obtain a representative sample of its contents. Sample was 

drawn through the sampling line into the analyzer at a flow rate of 7 L/min. Most of the sample 

was vented to the atmosphere, but a small portion of me sample entered the FID through a 

capillary. A backpressure regulator maintained a constant sample pressure, which maintained a 

constant sample flow rate in the capillary. The sample was oxidized by a hydrogen/air flame and 

the ionized carbon atoms produced in the flame were detected by an electrometer. 

The output signal (0 to 10 V dc full scale [FS]) from the analyzer was recorded by an 

Omega Engineering model OM-170 microprocessor-based portable data logger and a Hewlett- , 

Packard model 7132A strip chart recorder. Both instruments were operated on their 0- fo 10-V 

FS ranges. The data logger recorded the voltages at 2-second intervals throughout each test run. 

At the end of each day, the voltage measurements were transferred to a laptop computer 

containing a spreadsheet program. The strip chart recorder provided a visual indication of the 

styrene emissions measurements during each test ran and provided physical documentation for 

each test ran. . 

The THC analyzer was operated on Range 2 (0 to 200 ppm styrene) for most of the test 

rans, but was operated on Range 1 (0 to 20 ppm styrene) for three resin experiment rans in which 

low styrene concentrations were expected. These ranges are also equivalent to 0 to 53 ppm 

propane and 0 to 533 ppm propane. The THC analyzer was calibrated prior to each test ran 

using compressed gas calibration standards. A calibration drift check was done at the end of 

each test ran. Styrene calibration standards could not be used directly for routine calibrations 

during test rans because of cylinder pressure limitations associated with styrene's dewpoint. 

Instead, propane in air calibration standards without such pressure limitations were used for the 

routine calibrations. The calibration gases were 16,27,45,160,267, and 453 ppm propane. 

These calibration gases corresponded to 30 percent, 50 percent, and 85 percent of the two fullscale ranges, as called for in EPA Method 25A. 

Calibration data obtained from measurements of propane calibration standards could be 

used for tiie styrene emissions determination because RTI developed a correction factor for 

19 

^ 
P.32_ 

converting propane concentrations into the equivalent styrene concentrations prior to the testing. 

A styrene molecule has eight carbon atoms and a propane molecule has three carbon atoms. As a 

first approximation, one would expect die propane-to-styrene correction factor to equal die ratio 

of the carbon atoms (i.e., 8/3 = 2.667). The measured propane-to-styrene correction factor was 

2.686 for the 0- to 200-ppm styrene range on the THC analyzer. This measured correction factor 

was used in emission calculations. 

The propane calibration standards were verified by RTI using propane analytical 

reference standards. They were intercompared with styrene calibration standards to obtain the 

propane-to-styrene correction factor. The styrene calibration standards were verified by RTI 

using styrene analytical reference standards. The details of these measurements are presented in 

Appendix C (Volume II). 

Li general, six propane calibration standards, including die high-level, mid-level, and 

low-level calibration standards for the selected analyzer range, and zero air were measured 

during the calibration for the first test ran of each day. The three propane calibration standards 

for die selected analyzer range and zero air were measured during the calibrations for subsequent 

test runs. Calibration data for one test ran were used for the preceding test run's drift check, 

except for the last test run of die day when a separate drift check was conducted. The analyzer's 

zero and span pots were not adjusted during the entire 5-week testing period. The details of tiiese 

calibrations are presented in Appendix D (Volume D). 

The propane calibration standards were connected to the analyzer's calibration port via ah 

8-foot length of 1/8-inch ID PFA Teflon tubing. An in-line pressure regulator set to 5 psig and a 

needle valve maintained a constant flow rate in the tubing. Quick-connect fittings were used to 

switch from one calibration standard to the next. The analyzer required 15 minutes or more to 

yield a stable analyzer response for the first standard to be analyzed during a calibration, 

However, die stabilization period for subsequent calibration standards was only a few minutes. 

The cause for this long initial stabilization period was never determined, but it represented only a 

minor impediment to the calibrations. 

After die voltage readings from the styrene emissions measurements were transferred to 

the computer-based spreadsheet, they were converted into an average voltage for the test ran. 

The voltage associated with die background air measurement from the start of the test run was 

subtracted to yield a net average voltage. An average styrene concentration for the test run was 

obtained by multiplying the net average voltage by a styrene calibration factor. This calibration 

factor was obtained by dividing the equivalent styrene concentration for the high-level calibration 

standard by the difference between the voltages from the measurements of the high-level 

calibration standard and zero air. 

RTI checked for concentration stratification inside die exhaust stack during a pure styrene 

evaporation test by sampling the exhaust stream across two perpendicular traverses. These 

measurements, were made at 10 points on each traverse at distances corresponding to equal 

20 

'2^ 
P.33 

subdivisions of the exhaust stack's area. The sampling line was modified so that sample was 

collected from a single point in the exhaust stack. The styrene concentration was not stable 

during this pure styrene evaporation test, and the analyzer response declined from 2.17 to 1.32 V. 

Least squares regression was used to fit these data to an exponential decay curve with a 

coefficient of determination (i.e., r-squared) equal to 0.98. Individual measurements deviated 

from the regression curve by an average of 1.6 percent of the predicted value. The maximum 

deviation was 5.2 percent. This statistical analysis suggests that there is little concentration 

stratification in the exhaust stack. 

5.1.2 Exhaust Air Flow Rate Measurement 

Air velocity in the 34-inch diameter circular exhaust stack of the total enclosure was 

measured according to EPA Methods 1 and 2 as given in Code of Federal Regulations, Chapter 

40, Part 60. The measurements were made using a Dwyer series 160 stainless steel pitot tube 

(standard type) and a Dwyer series 2000 Magnehelic differential pressure gauge. The 

Magnehelic gauge was compared to an inclined manometer (a primary standard). Magnehelic 

readings were 95 percent (0.95) of manometer readings. This 0.95 correction factor was used in 

air flow rate calculations. The velocity was measured at a distance of approximately five to six 

stack diameters downstream of two right-angle bends in the exhaust stack. 

Velocity across two perpendicular traverses was measured weekly. These measurements 

were made at 12 points on each traverse at distances corresponding to equal subdivisions of the 

exhaust stack's area. These data were recorded in a data sheet and were transcribed into a 

computer-based spreadsheet for data reduction. In general, the weekly velocity measurements 

indicated that die exhaust air flow rate remained relatively constant for the entire 5-week testing 

period. The average exhaust air flow rate was 8,685 ftVmin for the entire testing period and 

individual weekly measurements varied from 8,358 to 9,034 ft3/min. The Reynolds number for 

the air flow in the 34-inch diameter exhaust stack was 3.97x10s, which places the flow in the 

turbulent regime. Therefore, any concentration stratifications were not likely to persist for long 

distances inside the exhaust stack. This conclusion is consistent with the negative results of the 

concentration stratification measurements. 

RTI checked for off-axis flow on one occasion by rotating the pitot tube inside the 

exhaust stack and recording the velocity head at various angles. The results of these 

measurements indicate that off-axis flow was not a problem in the exhaust stack. 

Velocity head (Ap) measurements at the centerline of the exhaust stack were usually 

performed at 15-minute intervals during each test run. The Magnehelic differential pressure 

gauge was used to obtain these measurements. In general, die centerline Ap remained relatively 

constant throughout each test run although there were short-term fluctuations on the Ap. The 15-

minute data were recorded in a data sheet and in a laboratory notebook during each test run and 

were transcribed into a computer-based spreadsheet for data reduction. The average centerline 

Ap for a test ran was used as a scaling factor for calculating an estimated average exhaust air 

21 

2 ( 
P.34 

flow rate for that test run. In general, the average centerline Ap remained relatively constant for 

the entire testing period. Individual values ranged from 0.109 to 0.133 inch of water with an 

overall average value of 0.120 inch of water. 

The exhaust flow rate during the test run was calculated according to the following 

formula: 

Q run = [avg (Ap run)0 7(Ap weekly)0 5] x Q weekly (5-1) 

where 

Q ran = exhaust flow rate during a test run (acfm) 

Q weekly = exhaust flow rate determined by weekly velocity traverse (acfm) 

avg (Ap run)05 = average square root of 15-minute Aps recorded at centerline 

during the test run 

(Ap weekly)05 = square root of Aps recorded during weekly velocity traverse. 

The relative humidity and temperature of the air in the spray booth were measured by a 

sling psychrometer during each test ran. The measurements showed that the ambient air 

temperature and relative humidity were very stable at 73±1 °F and 58±2 percent, respectively. 

5.1.3 Emissions Determined by Emission Measurement Method 

Styrene emission quantity (Em) for each test run was calculated by the following 

equation: 

Em,lb = 2.6xlO-9xQ.xMWxCxT (5-2) 

Em,g =1.18xlO"6xQxMWxCxT (5-3) 

where 

2.6x 10'9, 1.18x 10"6 = conversion factors to standard conditions (68° F and 29.92 inches 

mercury) in English and metric units, respectively 

Q = average exhaust air flow rate (actual cubic feet per minute) 

MW = molecular weight of styrene (104) 

C = average styrene emission concentration during the entire test run 

(ppmv actual) 

T = duration of test ran (minutes). 

Using the emission concentration profile and the exact duration of the application stage 

(Ta), an average emission concentration (Ca) could be calculated for the application stage in each 

test run. The total emissions during the application stage (Ea) could be calculated from the same 

equation: 

22 

Q.-7-
P.35 

Ea,lb = 2.6xlO"9xQxMWxCaxTa (5-4) 

Ea,g irl.lSxlO-'xQxMWxCaxTa (5-5) 

The difference between total emissions and emissions during the application stage is the 

emissions from the wet-out stage (for resin lamination), stagnant (curing) stage, and overspray. 

5.2 Mass Balance Calculation Method Using Gravimetric Measurements 

The mass balance calculation mediod involves weighing all materials, overspray, mold, 

and part in the beginning and at die end of a test ran. The difference between the total initial 

weight and the total final weight is the weight loss due to emissions. 

Weight losses due to styrene emissions were determined using two floor-type, highprecision scales (Sartorius Corporation, Model F150S). The scales have a 150,000-g capacity 

and 1-g readability. These two scales were calibrated with subsequent additions of standard 

weights - 1 g, 5. g, 10 g, 20 g, 50 g, 100 g, 500 g, 1,000 g, and 2,000 g - daily. The calibration 

procedures were performed on an empty scale and with a heavy object (i.e., an empty mold) on 

the scale. This dual calibration procedure ensured that the scales had the same sensitivity in the 

range of weights encountered in the tests. These calibration procedures showed that the scales 

precisely indicate die standard weights added. Scale drift was checked periodically by leaving a 

1,000-g or 2,000-g standard weight on the scale overnight. The drift check showed that these 

two scales were very stable and die overnight drifts were witiiin ±2 g. 

The first scale was used to measure the initial and final weights of gel coat or resin 

materials, catalyst, fiberglass reinforcement, glass veil, protective clothing, and kraft paper for 

ground cover. A second scale was specifically used for die mold and cart. The mold and cart 

were left on die second scale for die entire test ran. 

The gravimetric measurement procedures for die mass balance calculation mediod are 

outlined as follows: 

A. Before Application 

1. Determine the initial weight of ground cover (e.g., kraft paper) and thin glass veil 

(used to capture overspray droplets on filter bank) - W1. 

2. Determine die initial weight of tools and otiier items (e.g., wet-out rollers, gloves, 

booties, coverall) mat will come into contact widi the materials during the 

application - W2. 

3. Determine the initial weights of materials (i.e., gel coat, resin, catalyst, fiberglass 

roving, or chopped strand mat) to be used for part production. Weigh tiie pump 

23 

25 
P.36 

system including gel coat or resin container on the first scale to determine the initial 

weight of gel coat or resin material and catalyst - W3. 

4. Determine the initial weight of the empty mold with the cart and protective skirt on 

the second scale - W4. 

B. Preparation for Gel Coat or Resin Application 

1. Place ground cover on the floor around the second scale in the spray booth and attach 

glass veil on the filter bank to capture droplets from overspray. 

2. Place the empty mold and the cart (with protective skirt attached) on the second scale 

in the center of the spray booth. 

3. Apply gel coat or resin in a manner consistent with a typical operation. 

C. After Application 

1. Determine the final weights of materials (i.e., gel coat, resin, catalyst, fiberglass 

roving, or chopped strand mat) used for application. Take the reading of tbe whole 

pump system from the first scale to determine the final weight of gel coat or resin 

material and catalyst - W5. 

2. Take a measurement reading of the second scale for the mold with the wet gel coat 

or resin after application is completed - W6. 

3. For resin lamination, take another measurement reading of the second scale for the 

mold with me part, after wet-out rolling is completed - W7. 

D. After Complete Curing 

1. Determine the final weight of the mold with cured gel coat or resin laminate on the 

second scale - W8. 

2. Determine die final weight of ground cover and thin glass veil - W9. 

3. Determine the final weight of tools and items (e.g., wet-out rollers, gloves, booties, 

coverall) that came into contact with the materials during the application. (Wet-out 

rollers can be weighed right after they are used so that resin residue can be cleaned 

from the rollers) -W10. 

24 

ZL 4-
P.37 

E. Transfer Efficiency 

From the weights of materials used and materials applied on the mold, calculate the 

transfer efficiency for each test ran. Transfer efficiency = (W6-W4)/(W3-W5). 

F. Emissions from Part During Stagnant (Curing) Period 

Emissions from the gel coat on the mpld during the stagnant (curing) period can be 

determined from the weight loss after the spraying and complete curing = W6-W8. 

Emissions from the resin laminate during the stagnant (curing) period can be determined 

from the weight loss between when the wet-out rolling was completed and curing was 

completed. During this period the mold remained on die second scale. Emissions from 

the resin laminate only during the stagnant period = W7-W8. 

G. Total Emissions 

Total emissions (including emissions from the application stage, the wet-out rolling stage, 

the stagnant [curing] period, and overspray) = Materials used (W3-W5) - Materials on the 

mold (W8-W4) - Materials not on the mold (W9+W10-W1-W2). 

A data recording sheet used for the testing is shown in Figure 5-1. This data recording 

sheet records more detailed measurements so tiiat glass ratio and catalyst ratio can also be 

calculated. 

25 

2-S" 
Ov 

Data Recording Sheet for Mass Balance Calculation 

Date: Time: Recorded by: 

Test run#: 

Wet bulb: 

Material/container #: 

Dry bulb: 

Equipment: 

RH%: 

Application technique: normal/controlled 

Air velocity: low/high Baffle: with/without 

Initial (g) Final (g) Change (g) 

1 Mass of rear veil with a roll of wide masking tape 

2. Mass of ground cover/front veil/masking tape/booties/gloves/pants/stool 

2a. Mass of ground cover and a roll of narrow masking tape 

2b. Mass of front veil with existing masking tape 

2c. Mass of booties/gloves/pants/stool 

3. Mass of wet-out rollers in container 

4. Mass of fiberglass roving or chopped strand mat 

5. Mass of resin or gel coat material 

6a. Volume of catalyst, ml (catalyst type/#: ) 

6b. Mass of catalyst 

7a. Mass of scale cover + empty mold + skirt + duct tape (fan off) 

7b. Mass of scale cover + empty mold + skirt + duct tape (fan on before application) 

8a. Mass of scale cover + wet mold + skirt + duct tape (at the end of application) 

8b. Mass of scale cover + wet mold + skirt + duct tape (at the end of rolling) 

9a. Mass of scale cover + cured mold + skirt + duct tape (fan on) 

9b. Mass of scale cover + cured mold + skirt + duct tape (fan off) 

Sp.gr. 

1 

Weight(g) Time 

10. Mass of material used (M4 + M5 + M6b) 

11. Mass of cured material on mold + skirt + scale cover (M9b-M7a) 

12. Mass of cured materials deposited elsewhere (M1 +M2 + M3) 

13. Total emissions (M10-M11-M12) 

14. Curing emissions from mold and skirt (M8a-M9a) 

15. Glass ratio (M4/(M4 + M5)) 

16. Catalyst ratio (M6b/M5) 

17. Transfer efficiency l(M8a-M7b)/M 101 

Note: 

Figure 5-1. Data recording sheet for mass balance calculation (used in the testing at Reichhold). BLANKRES.XLS 

oo 
P.39 

Chapter 6 

Test Results and Discussions 

A spreadsheet containing die emission measurements, gravimetric measurements, and 

calculated emission quantities and emission factors is provided in Appendix E (Volume IT). 

Table 6-1 summarizes the emission measurements and calculated emission factors for three 

experiments. The test results were subject to analysis of variance (ANOVA) to determine the 

significance of variables on styrene emissions. The detailed results of this statistical analysis are 

included in Appendix F (Volume II). Table 6-2 compares variables that affect total emissions as 

measured by THC. Infonnation in Table 6-2 is extracted from Table 17 in Appendix F. 

The level of significance of the comparison is presented by the number of asterisks — the 

more asterisks, the more confidence that there is a significant difference in the comparison. The 

majority of the comparisons are significant at the 0.001 level (or 99.9 percent confidence 

interval), noted by **?". This means that if the test is repeated 100 times, 99.9 percent oi" die test 

results will show a difference between the two variables compared. A few variables are 

significant at 0.01 or 0.05 levels (99 or 95 percent confidence intervals), noted by ** and *, 

respectively. If the comparison is not statistically significant at the 0.05 level, it is noted by "ris." 

Table 6-2 shows that, in the pilot experiment, normal and controlled spraying techniques 

caused a difference in total emissions and the difference is significant at the 0.001 level. The 

high and low air velocity in the spray booth did not make a difference in total emission and the 

difference was not significant at the 0.05 level. 

The gel coat experiment shows diat the regular and low-VOC gel coat made a difference 

in total emissions and the difference is significant at the 6.001 level. The total emissions from 

three gel coat spray guns are not significantly different at the 0.05 level. 

In the resin experiment, the difference in total emissions from low-profile (general 

purpose) resin and low-styrene resin is significant at the 0.01 level. The differences between 

low-profile resin and styrene-suppressed resin or styrene-suppressed resin with additional wax 

are significant at the 0.001 level. This implies that emission reductions achieved by using lowstyrene resin, styrene-suppressed resin, and styrene-suppressed resin with additional wax are 

statistically significant. However, total emissions between styrene-suppressed resin and styrenesuppressed resin with additional wax are not significantly different. This implies that the 

emission reduction achieved by adding wax to the styrene-suppressed resin is not statistically 

significant at the 0.05 level. 

Similarly, emissions generated from the flow coater and pressure-fed roller are 

significantly different from those from the AAA spray gun at die 0.001 level. However, the 

emissions generated from the flow coater and the pressure-fed roller are not significantly 

different. 

27 

2/*-
Table 6-1. Summary of Emission Measurements and Calculated Emission Factors 

Test run #lMat6Equip. 

| 1 container # 

Application 

Method 

EXPERIMENTAL RUNS 

i • ' 

RFI-EXPJRF1IRE1 

GFI-EXPIGF1IGE1 

j ; 

: : 

PILOT EXPERIMENT 

PI |GF1|GEI 

P2 iGFllGEl 

P3 IGFllGEl 

P4 IGFllGEl 

P5 IGFllGEl 

P6 ,GFIIGE1 

P7 IGFllGEl 

P8 IGFllGEl 

P9 |GF1|GE1 

P10 ' iGFllGEl 

PU SGFIIGEI 

P12 jGFl 

i

 ! 

GEI 

Average (12 runs) 

! j 

Normal 

Normal 

Controlled 

Normal 

Controlled 

Normal 

Controlled 

Normal 

Controlled 

Normal 

Controlled 

Controlled 

Normal 

Normal 

Ml-Normal spraying (6 runs) 

M2-Contro1led spraying (6 runs) 

1 1 

A2-High air velocity (6 rans) 

A1-Low air velocity (6 runs) 

1 1 

Ml/Al(3runs)| 

M2/AI (3 runs)! 

MI/A2(3runs)l 

M2/A2 (3 runs) 1 

•; J s 

Air 

Vel. 

High 

High 

Low 

High 

High 

High 

Low 

Low 

High 

Low 

High 

Low 

High 

Low 

Total 1 Emissions | Total 

emissions 

by THC. g 

631 

456 

322 

536 

382 

526 

397 

506 

.

 4 27 

554 

422 

396 

479 

476 

452 

513 

391 

462 

442 

512 

372 

514 

410 

during 

application, g 

(by THC) 

328 

228 

134 

310 

138 

253 

134 

219 

157 

271 

176 

145 

214 

• 204 

196 

245 

147 

208 

184 

231 

138 

259 

157 

emissions 

*y MB. g 

886 

478 

380 

607 

442 

415 

412 

506 

466 

499 

389 

457 

535 

442 

463 

501 

424 

476 

449 

482 

416 

519 

432 

Material 

used.g 

9287 

1564 

1564 

2261 

1695 

2067 

1964 

2204 

1900 

2056 

2064 

2021 

2077 

2049 

1994 

2119 

1868 

2011 

1976 

2103 

1850 

2135 

1886 

' Transfer 

eff.% 

90.1 

75.5 

79.8 

66.1 

80.0 

74.0 

85.1 

75.7 

81.2 

73.8 

85.0 

82.6 

74.5 

77.7 

78.0 

73.6 

82.3 

76.8 

79.1 

75.7 

82.5 

71.5 

82.1 

Styrene 

content. % 

38.33 

38.75 

38.75 

38.75 

-38.75 

38.75 

38.75 

38.75 

38.75 

38.75 

38.75 

38.75 

38.75 

38.75 

38.75 

38.75 

38.75 

38.75 

38.75 

38.75 

38.75 

38.75 

38.75 

Emission Factors 1 

%AS Jj/m2| g/g 

by THC byTHClbyTHC 

17.7 

75.2 

53.1 

61.2 

58.2 

65.7 

52.2 

59.2 

58.0 

69.6 

52.7 

50.6 

59.5 

60.0 

58.3 

-62.5 

54.1 

59.2 

57.4 

62.9 

52.0 

62.1 

56.3 

Note: THC=THC emission measurement. MB=mass balance measurement. EF=emission factor, %AS=% available styrene. 

g/g=g of emission per g of material used. 1 II I 

1 

277 

200 

0.068 

0.291 

i 

1 

141 

236 

168 

231 

175 

222 

0.206 

•0.237 

0.225 

0.254 

0.202 

0.230 

1881 0.225 

244 

.185 

174 

210 

209 

199 

225. 

172 

203 

194 

225 

163 

226 

180 

0.270 

0.204 

0.196 

0.231 

0.232 

0.226 

0.242 

0.210 

0.229 

0.223 

0.244 

0.201 

0.241 

0.218 

1 

(con.) 

28 

2JS 

SUMSUM.XLS 
P.41 

Table 6-1. Summary of Emission Measurements and Calculated Emission Factors 

i 

1 1 ' : 

Test run #|Matd Equip. 

| 'container # 

Application 

Method 

GELCOAT EXPERIMENT 

! 

I d GFIIGE3 

lG2 GFHGE2 

JG3 GF1|GEI 

G4 GF2IGEI 

|G5 GFIIGE1 

IG6 IGFllGEl. 

G7 GF2IGE3 

G8 GF1IGE3 

G9 ;GF1IGE2 

GIO ,GFl|GE3 

GI 1 GF2IGE2 

;G12 GF2IGE2 

GI3 GF2IGE2 

G14 GF2IGE1 

G15 GF1|GE2 

G16 GF2|GEI 

GI7 JGF2|GE3 

GI8 ,GF2IGE3 

I ; 

Average (18 runs) 

1 i 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

GFlrReguIar gel coat (9 runs) 

GF2-Low VOC gel coat (9 runs) 

1 ! ! 1 

GEl-AAA ext mix gun (6 runs) 

GE2-HVLP int mix gun (6 runs) 

GE3-HVLP ext mix gun (6 runs) 

i • • 

GF1/GE1 (3 runs) 

GFI/GE2 (3 runs) 

GF1/GE3 (3 runs) 

GF2/GE1 (3 runs) 

GF2/GE2 (3 runs) 

GF2/GE3 (3 runs) 

1 i ; • — 

1 

Note: THC=THC emission measureme 

g/g=g of emission per g of material used 

Air 

Vel. 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

nt. MB=i 

. 

Total i 

emissions i 

by THC. g 

3951 

3951 

409 

273 

403 

387 

271 

382 

386 

384 

294 

249 

291 

267 

339 

274 

298 

282 

332 

387 

278 

336 

326 

335 

400 

373 

387 

272 

278 

284 

nass balance 

1 

Emissions 

during 

application, g 

(by THC) 

154 

164 

158 

91 

154 

142 

80 

143 

155 

134 

94 

94 

112 

92 

162 

99 

100 

93 

123 

152 

95 

123 

| 130 

1 117 

1 151 

1 160 

1 143 

1 94 

1 too 

1 91 

! 

measurement. E 

1 

Total 

emissions 

by MB. g 

348 

406 

404 

227 

355 

410 

273 

472 

398 

360 

327 

346 

374 

332 

387 

302 

310 

286 

351 

393 

309 

338 

373 

342 

390 

397 

393 

287 

349 

290 

.F=emission 

1 

Material 

used.g 

1723 

1808 

1756 

1929 

1765 

1817 

1876 

1891 

1787 

1723 

1940 

1940 

2245 

1933 

1776 

2128 

2275 

1963 

1904 

1783 

2025 

1888 

1916 

1909 

1779 

1790 

1779 

1997 

2042 

2038 

r

actor. %A 

1 

Transfer 

eff.% 

84.6 

81.4 

79.0 

88.8 

84.3 

82.9 

87.3 

80.0 

82.4 

84.7 

83.3 

81.9 

81.1 

81.9 

82.0 

87.4 

85.7 

85.4 

83.6 

82.4 

84.8 

84.1 

. 82.0 

84.6 

82.1 

81.9 

1 83.1 

1 86.0 

I 82.1 

j 86.1 

! 

S=% avai 

! 

Styrene 

content. % 

38.75 

38.75 

38.75 

25.35 

38.75 

38.75 

25.35 

38.75 

38.75 

38.75 

25.35 

25.35 

25.35 

25.35 

38.75 

25.35 

25.35 

25.35 

32.05 

38.75 

25.35 

32.05 

32.05 

• 32.05 

38.75 

38.75 

38.75 

25.35 

25.35 

25.35 

able styrene 

1 

i 

Emission Factors 

%AS 

by THC 

59.2 

56.4 

60.2 

55.8 

58.9 

54.9 

56.9 

52.1 

55.7 

57.6 

59.8 

50.6 

51.2 

54.6 

49.2 

50.9 

51.7 

56.6 

55.1 

56.0 

54.2 

55.9 

53.8 

55.7 

58.0 

53.8 

56.3 

53.7 

53.9 

55.1 

1 

g/m2 .g/g 

by THC by THC 

174 

174 

180 

120 

177 

170 

119 

168 

169 

169 

129 

109 

128 

117 

149 

120 

131 

124 

146 

170 

122 

• 147 

143 

147 

176 

164 

170 

119 

122 

124 

0.229 

0.218 

0.233 

0.141 

0.228 

0.213 

0.144 

0.202 

0.216 

0.223 

0.152 

0.128 

0.130 

0.138 

0.191 

0.129 

0.131 

0.144 

0.177 

0.217 

0.137 

0.180 

0.172 

0.179 

0.225 

0.208 

0.218 

0.136 

0.137 

0.140 

1 

(con.) 

29 

2^ 

SUMSUM.XLS 
P.42 

Table 6-1. Summary of Emission Measurements and Calculated Emission Factors 

(con.) 

I i 

1 i ••-

1 j 

Test run #| Matt Equip. 

; {container # 

RESIN EXPERIMENT 

Rl IRF6IRE1 

R2 iRFllRE2 

R3 JRFHRE3 

R4 !RFllRE3 

1R5 IRFliREl 

!R6 JRF3JREI 

R7 IRF1 

R8 |RF2 

R9 RF4 

RIO |RF1 

Rll JRF6 

R12 IRF6 

R13 |RF2 

R14 |RF2 

RI5 !RF1 

RI6 |RF1 

RI7 |RF4 

RI8 IRF1 

R19 RF3 

R20 IRF3 

R21 |RFI 

R22 IRFI 

R23 

R24 

R25 

RF4 

RF1 

REI 

REI 

RE4 

REI 

REI 

REI 

REI 

REI 

REI 

RE3 

RE4 

RE2 

REI 

REI 

REI 

REI 

RE4 

RE2 

RF4IRE4 

i 

Application 

Method 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Normal 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Controlled 

Average (25 runs, w "Normal" run RIO) 

Air 

Vel. 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Low 

Law 

Low 

Low 

Average (24 runs, w/o "Normal" run RIO) 

i : I . I 

REI/RFl-AAA ext mix gun (6 runs, w/ RIO) 

RE1/RF1-AAA ext mix gun (5 runs, w/o RIO) 

RE2-Flow coater (3 runs) | 

RE3-Pressure-fed roller (3 runs) 

Total 

emissions 

by THC. g 

316 

305 

286 

279 

440 

296 

404 

389 

743 

636 

267 

217 

. 403 

394 

453 

332 

.762 

293 

291 

272 

468 

459 

524 

322 

500 

402 

392 

477 

445 

306 

299 

RE4-AAA ext mix gun for BPO system (see RF4) 

RF2-Low styrene Resin (3 runs) 

RF3-Styrene suppressed resin (3 runs) 

RF4-BPO-Catalyzed Resin (4 runs) 

RF4-BPO-Catalyzed Resin (2 runs, slow gel) 

RF4-BPO-Catalyzed Resin (2 runs, fast gel) 

RF5-Water emulsified resin (Not tested) 

RF6-Styrene suppressed resin plus wax (3 runs) 

1 11 1 

395 

286 

632 

752 

512 

NA 

266 

Emissions 

during 

application, g 

(by THC) 

196 

169 

136 

142 

212 

193 

207 

195 

266 

310 

153 

97 

192 

191 

228 

221 

356 

126 

166 

180 

216 

207 

192 

134 

193 

195 

190 

230 

214 

' 143 

166 

192 

180 

252 

311 

193 

NA 

149 

Total 

emissions 

by MB, g 

284 

335 

267 

280 

434 

302 

424 

361 

694 

607 

247 

203 

374 

366 

442 

336 

732 

265 

262 

273 

428 

431 

488 

289 

488 

384 

375 

461 

432 

296 

294 

367 

279 

601 

713 

488 

NA 

245 

Material 

used, g 

7712 

5445 

4919 

5041 

5978 

5663 

6160 

5979 

6116 

6133 

5152 

4872 

6566 

6870 

7000 

5328 

7467 

5371 

6689 

6423 

6958 

7256 

5606 

6040 

5698 

6098 

6096 

6581 

6670 

5619 

5096 

6472 

6258 

6222 

6792 

5652 

NA 

5912 

Transfer 

eff. % 

92.7 

96.2 

97.2 

97.3 

90.8 

91.7 

91.0 

914 

88.7 

80.5 

89.9 

92.7 

91.4 

93.2 

92.6 

96.7 

79.5 

97.7 

92.9 

92.9 

92.2 

93.5 

91.7 

97.9 

91.9 

92.2 

92.7 

90.1 

92.0 

97.3 

97.1 

92.0 

92.5 

88.0 

84.1 

91.8 

NA 

91.8 

Styrene 

content, % 

43.29 

38.33 

38.33 

38.33 

38.33 

43.45 

38.33 

35.34 

42.61 

38.33 

43.29 

43.29 

35.34 

35.34 

38.33 

38.33 

42.61 

38.33 

43.45 

43.45 

38.33 

38.33 

42.61 

38.33 

42.61 

39.87 

39.93 

38.33 

38.33 

38.33 

38.33 

35.34 

43.45 

42.61 

42.61 

42.61 

NA 

43.29 

Emission Factors 

%AS 

by THC 

9.5 

14.6 

15.2 

14.5 

19.2 

12.0 

17.1 

18.4 

28.5 

27.1 

12.0 

10.3 

17.4 

16.2 

16.9 

16.3 

23.9 

14.2 

10.0 

9.8 

17.5 

16.5 

21.9 

13.9 

20.6 

16.5 

16.1 

19.1 

17.5 

14.2 

15.3 

17.3 

10.6 

23.7 

26.2 

21.3 

NA 

10.6 

Note: THC=THC emission measurement, MB=mass balance measurement, EF=emission factor. %AS=% available styrene. 

g/g=g of emission per g of material used. 

g/m2 

by THC 

138 

134 

125 

123 

193 

130 

' 177 

170 

• 326 

279 

117 

95 

177 

173 

199 

146 

334 

129 

127 

119 

205 

201 

230 

141 

219 

175 

172 

209 

195 

134 

131 

173 

126 

277 

330 

225 

NA 

117 

g/g 

by THC 

0.041 

0.056 

0.058 

0.055 

0.074 

0.052 

0.066 

0.065 

0.122 

0.104 

0.052 

0.044 

0.061 

0.057 

0.065 

0.062 

0.102 

0.055 

0.043 

0.042 

0.067 

0.063 

0.094 

0.053 

0.088 

0.065 

0.064 

0.073 

0.067 

0.055 

0.059 

0.061 

0.046 

0.101 

0.112 

0.091 

NA 

0.046 

30 SUMSUM.XLS 
P.43 

Table 6-2. Significance of Variables Affecting Total Styrene Emissions 

Comparison Significance 

Pilot experiment 

Normal vs. Controlled spraying 

High vs. Low air velocity 

*** 

ns 

Gel coat experiment 

Regular vs. Low-VOC 

AAA (ext) vs. HVLP (int) 

AAA (ext) vs. HVLP (ext) 

HVLP (int) vs. HVLP (ext) 

*** 

ns 

ns 

ns 

Resin experiment 

Low-profile vs. Low-styrene 

Low-profile vs. Styrene-suppressed 

Low-profile vs. Styrene-suppressed+wax ' 

Low-styrene vs. Styrene-suppressed 

Low-styrene vs. Styrene-suppressed+wax 

Styrene-suppressed vs. Styrene-suppressed+wax 

AAA vs. Flow coater 

AAA vs. Pressure-fed roller 

Flow coater vs. Pressure-fed roller 

Regular vs. BPO-catalyzed (fast gel) 

Regular vs. BPO-catalyzed (slow gel) 

BPO-catalyzed slow gel vs. fast gel 

* 

*** 

*** 

*** 

*** 

ns 

*** 

*** 

ns 

** 

*** 

*** 

ns = Not statistically significant at 0.05 level. 

* = Statistically significant at the 0.05 level. 

** = Statistically significant at the 0.01 level. 

*** = Statistically significant at the 0.001 level. 

The emissions from the BPO-catalyzed resin (either neat resin with slow gel or modified 

resin with fast gel) are different from the regular resin under controlled spraying. The emissions 

from the neat BPO-catalyzed resin are also significantly different from those from the modified 

BPO-catalyzed resin. 

The following results and discussions are based on total emissions quantified by the 

emission measurement method. The percent reduction is based on the averages of total 

emissions for the number of test rans conducted under the same conditions. The same 

31 

B l 
P.44 

percentage of reduction is also achieved when the emissions are expressed in grams/square meter 

because the same mold surface area is used in the denominator to calculate the emission factors. 

6.1 Distribution of Total Emissions During Application and Curing Stages 

Tables 6-3 and 6-4 show the distribution of emissions in gel coat and resin experiments. 

The emission quantities are the averages of the number of test runs conducted for that condition. 

Total emissions and emissions during the application stage were determined by emission 

measurement method using the procedures outlined in Section 5.1.3. The difference between 

total emissions and emissions during the application stage is postapplication emissions. The 

postapplication emissions included emissions from the wet-out rolling (for resin lamination), 

stagnant (curing) period, and the curing of overspray. 

Table 6-3. Distribution of Emissions in Pilot and Gel Coat Experiments 

Gel coat application condition 

Pilot experiment (gel coat spraying) 

Normal spraying/high air velocity (3 rans) 

Controlled spraying/high air velocity (3 mns) 

Normal spraying/low air velocity (3 runs) 

Controlled spraying/low air velocity (3 runs) 

Gel coat experiment (controlled spraying) 

Regular gel coat/AAA-external mix (3 rans) 

Regular gel coat/HVLP-internal mix (3 runs) 

Regular gel coat/HVLP-external mix (3 runs) 

Low-VOC gel coat/AAA-external mix (3 runs) 

Low-VOC gel coat/HVLP-internal mix (3 rans) 

Low-VOC gel coat/HVLP-external mix (3 runs) 

Range 

Average 

Total 

emissions 

g 

514 

410 

512 

372 

400 

373 

387 

272 

278 

284 

Emissions 

during 

application 

g 

259 

157 

231 

138 

151 

160 

143 

94 

100 

91 

% total 

50 

38 

45 

37 

38 

43 

37 

35 

36 

32 

32-50 

39 

Postapplication 

emissions 

g 

255 

253 

281 

234 

249 

213 

244 

178 

178 

193 

% total 

50 

62 

55 

63 

62 

57 

63 

65 

64 

68 

50-68 

61 

32 

& 
P.45 

Table 6-3 shows that 32 to 50 percent (average 39 percent) of total emissions was 

emitted during me gel coat spraying stage and the remainder was emitted during the 

postapplication (curing) stage. Figure 6-1 shows the amount of styrene emitted for each of the 

gel coat application conditions. It is apparent that controlled spraying emitted less styrene than 

normal spraying, and the low-VOC gel coat emitted less styrene than the regular gel coat. The 

pilot experiment also showed that low and high linear air velocities in the spray booth (between 

40 and 100 ft/min) did not have an effect on emissions. Figure 6-1 also shows that there is no 

significant difference in total emissions for three different spray guns (i.e., AAA spray gun with 

external catalyst mixing and HVLP spray gun with internal and external catalyst mixing). More 

detailed discussion is presented in Section 6.3. 

Table 6-4 shows that 38 to 63 percent (average 50 percent) of total emissions was 

emitted during the resin application stage and the remainder was emitted during the 

postapplication stage. The postapplication stage included wet-out rolling and stagnant (curing) 

periods. Figure 6-2 shows the styrene emissions quantified for each of the resin application 

conditions. It is apparent that the flow coater and the pressure-fed roller resulted in less 

emissions than normal or controlled resin sprayup. Low-styrene and styrene-suppressed resins 

also emitted less styrene than the low-profile resin. More detailed discussions for the resin 

experiment are presented in Section 6.4. 

Table 6-4. Distribution of Emissions in Resin 

Resin application condition 

AAA-normal spraying (1 mn) 

AAA-controlled spraying (5 runs) 

Flow coater (3 runs) 

Pressure-fed roller (3 runs) 

Low-styrene resin (3 runs) 

Styrene-suppressed resin (3 rans) 

Styrene:suppressed resin + wax (3 runs) 

Neat BPO resin - slow gel (2 runs) 

BPO resin + thickener - fast gel (2 runs) 

Range 

Average * 

Total 

emissions 

• g 

636 

445 

306 

299 

395 

286 

266 

752 

512 

i Experiment 

Emissions during 

application 

• g 

310 

214 

143 

166 

192 

180 

149 

311 

193 

% total 

49 

48 

47 

56 

49 

63 

56 

41 

38 

38-63 

50 

Postapplication 

emissions 

g. 

326 

231 

163 

133 

203 

106 

117 

441 

319 

% total 

51 

52 

53 

44 

51 

37 

44 

59 

62 

37-62 

50 

33 

33 
\t 

P£ 

Styrene emissions, g 

Normal/high velocity 

Controlled/high 

•n 

oa 

c i 

(D -1

CO . O 

CO 

r* 

•n 

CT 

c 

O 

3 

o 

^ t 

a 3 

(0 

CO 

o 3 

CO 

3 

r-> 

3" 

(D 

•ilo o r » 

fi) 

3 

a 

(Q 

<D 

o 

o fi) 

f * 

CD 

X 

"O 

• * 

3 

CntsD 

. 

O CP 

o 

o 

. o> 

OJ 

•o Tlica

3 t o 3 

O 

o 3 

Q. 

0-+ 

O 

3 

velocity 

Normal/low velocity 

Controlled/low 

velocity 

Regular/AAA-ext 

Regular/HVLP-int 

Regular/HVLP-ext 

Low-VOC/AAA-ext 

Low-VOC/HVLP-int 

Low-VOC/HVLP-ext 

9frd 
_ ^ ? 

S£ 

Styrene emissions, g 

o o 

M (O 

O O 

O O 

o o 

Ul o o 

0> -4 

O O 

O O 

09 

o 

o 

AAA-ext (normal 

spraying) 

•n 

CQ 

c • ^ 

CD 

CO 

• 

IO 

• O 

CO 

s? 

o* 

c 

o 

3 

O -*• 

CD ss

3 i o 3 

CO int 

3" 

CD 

•n 

CD 

CO 

3* 

CD 

X 

•o CD 

•-. 

d CD 

3 

r* 

73 

CD 

en 3 

0) 

" O 

TJ 

O 

fi) 

S2t 

O 

3 

O 

O 

3 

Q. 

r-+ 

o 3 

AAA-ext (controlled 

spraying) 

Flow coater 

Pressure-fed roller 

Low styrene Resin 

Styrene-suppressed 

resin 

Styrene-suppressed 

resin + wax 

BPO-catalyzed resin 

(slow gel) 

BPO-catalyzed resin 

(fast gel) 

. ' 

HHH 

• • 

• • 

•-

'"HH ^^^^^^H 

. 

^^^^^^^^^^^^^^^^H ^^^^^^^^^^^^^H ^^^^^^^^^^^^^^1 

•• 

H 

• • 

Hi 

• 

• mm 

• Postapplicatio

n s 

O Applicatio

n stage 

(age 

. 

LVd 
P.48 

6.2 Pilot Experiment Results 

Typical emission concentration profiles recorded by the THC analyzer for various test 

runs are presented and their resultant emission quantities are used in the following discussions. 

A comparison of typical emission concentration profiles provides a clear picture of what 

happened when different techniques, equipment, and materials were used. A test ran began when 

spraying or nonspraying application started and ended when the curing was completed. The end 

of the zigzag-like concentration profile indicates the end of die application stage. The average 

concentration and the duration of application are used to calculate emissions during the 

application stage. As soon as the application is completed, the emission concentration gradually 

returns to die baseline concentration during the wet-out rolling and curing stages. 

Figure 6-3 shows the typical emission concentration profiles for normal and controlled 

spraying test runs for the regular gel coat. Average styrene concentration during the application 

stage of the normal spraying test ran P6 (59 ppm) is higher than that of the controlled spraying 

test ran P10 (41 ppm). 

Using the total emissions data presented in Table 6-3 and normal spraying/high air 

velocity as the baseline condition, Figure 6-4 shows the emission reduction observed in die pilot 

experiment. Controlled spraying reduced emissions by 27 percent and 20 percent at low and high 

air velocity conditions, respectively. 

Table 6-5 shows the summary of emissions for the pilot experiment. Transfer efficiency 

increased and gel coat usage decreased when spraying technique improved. Total emissions and 

emission factors also reduced when spraying technique changed from normal to controlled 

spraying. However, the effects of air velocity under each spraying technique are not significant. 

Table 6-5. 

Spraying 

technique/air 

velocity 

Normal/High 

(3 runs) 

Controlled/ 

High (3 runs) 

Normal/Low 

(3 runs) 

Controlled/ 

Low (3 runs) 

Summary 

Transfer 

efficiency 

71.5 

82.1 

75.7 

82.5 

of Emissions for Normal and Controlled Gel Coat Spraying 

Materials used 

g 

2,135 

1,886 

2,103 

1,850 

Reduc. 

(%) 

-

12 

-

12 

Total emissions 

g 

514 

410 

512 

372 

Reduc. 

(%) 

-

20 

-

27 

Emission factor 

%AS 

62.1 

56.3 

62.9 

52.0 

Reduc. 

(%) 

— 

9 

-

17 

Emission factor. 

g/g 

0.241 

0.218 

0.244 

0.201 

Reduc. 

(%) 

-

10 

-

18 

"tote: Material usage and emission quantities are the averages of the number of test runs for that condition. 

%AS = percent of available styrene in gel coat. 

g/g = gram of styrene emitted per gram of gel coat material used. 

36 

3d 
P.49 

Normal spraying of gel coat (run P6) ' 

-->-\ I'll) . 

90 

80 

70 4 

»*lfrt*WttMjh 

Controlled spraying of geicoat (run P10) 

10 20 30 40 

Elapsed time, minutes 

50 60 

Figure 6-3. Typical emission concentration profiles for normal and controlled gel coat 

spraying. 

37 

3> 
00 oo 

c 

a> 

o 

w 

0) 

3 

c 

o 

'•5 

TI 

c 

o 

o 

0 

c 

• » 

10 

(0 

.o 

E 

o 

c 

.o 

•3 

U 

3 

XJ 

0> 

w 

.2 

E 

UJ 

30 

25 

20 

15 

10 

0 4 

Normal 

spraying/Low 

air. velocity 

Controlled 

spraying/Low 

air velocity 

Normal 

spraying/High 

air velocity 

(baseline) 

Controlled 

spraying/High 

air velocity 

Condition 

Figure 6-4. Emission reductions observed in the pilot experiment 

(based on total emissions, or emission factors in grams per square meter). 

in 
P.51 

6.3 Gel Coat Experiment Results 

Figure 6-5 shows the typical emission concentration profiles for a regular gel coat and a 

low-VOC gel coat test ran. Average styrene concentration during the application stage of the 

regular gel coat was 45 ppm, which is higher than the 26 ppm for the low-VOC gel coat. The 

emission reduction from the low-VOC gel coat is evident. 

Figure 6-6 shows the emission concentration profiles of the AAA spray gun with external 

catalyst mixing, the HVLP spray gun with internal catalyst mixing, and the HVLP spray gun with 

external catalyst mixing. These concentration profiles are similar in magnitude and the total 

emissions are not significantly different among these three spray guns. 

Using the total emissions data presented in Table 6-3 and the regular gel coat/AAA spray 

gun controlled spraying as the baseline condition, Figure 6-7 shows the emission reductions 

observed in the gel coat experiment. The low-VOC gel coat reduced total emissions by 28 to 32 

percent when compared to the regular gel coat. The changes in emission among these three 

spray guns are not significant. 

Because the effect of spray guns on total emissions was not significant, nine regular and 

nine low-VOC gel coat test runs were combined to compare the effects of different gel coat 

formulations. Total emissions and emission factors were calculated from the averages of nine 

test rans in each gel coat formulation and presented in Table 6-6. Table 6-6 shows that the lowVOC gel coat reduced total emissions by 28 percent when compared to the regular gel coat under 

controlled spraying conditions. When the emission factors are presented as percent available 

styrene (%AS), there is a little or insignificant reduction of 3 percent. This is because the styrene 

contents of the gel coats canceled out the effects of emission reduction in the emission factor 

calculation. When the emission factors are presented as g of styrene emitted per g of .gel coat 

applied, the low-VOC gel coat achieved 37 percent reduction. SCAQMD Rule 1162 static 

emission measurements for these two gel coats indicate that there is a 37 percent reduction. 

Table 6-6. Summary of Emissions for Regular and Low-VOC Gel Coats 

Type of gel 

coat 

Regular 

(9 runs) 

Low-VOC 

(9 runs) 

Materials 

used 

g 

1,783 

2,025 

Total 

emissions 

g 

387 

278 

Reduc. 

(%) 

— 

28 

Emission factor 

%AS 

56.0 

54.2 

Reduc. 

(%) 

— 

3 

Emission factor 

g/g 

0.217 

0.137 

Reduc. 

(%) 

— 

37 

Rule 1162 static 

emissions 

g/m2 

133 

83 

Reduc. 

(%) 

— 

37 

Note: Material usage and emission quantities are the averages of the number of test runs for that material. 

%AS = percent of available styrene in gel coat. 

g/g = gram of styrene emitted per gram of gel coat material used. 

39 

5^ 
P.52 

Controlled spraying of regular gel coat (run G6) 

.10 

0 

90 

80 

70 

& 60 

| 50 

(0 

£i 40 

o o 

§ 30 

O 

20 

10 

0 

| 1 ^**-

^*^^W 1 »H-*wt^ » 

•"" Controlled spraying.of low-vuc, geicoat (run uioi 

il i I L T

^KM4m^m... _ 

1 1 1 1 -H -H 

10 20 30 40 

Elapsed time, minutes 

50 60 

Figure 6-5. Typical emission concentration profiles for regular and low-VOC gel 

coats. 

40 
P.53 

E 

a 

a 

c 

o 

c 

a> 

u 

c 

o o 

E 

a 

a. 

c 

o 

o o 

c 

o o 

***W * 

5 40 

10 

1 . » - • 

AAA, external-mix spray gun (run G5) 

HVLP, internal-mix spray gun (run G9) 

H 

J 

JJ ill I 

HP 

"" HVLP, external-mix spray gun (run G8) 

M^MW^r^^^jj^rjjjjJ^ 

* liiMH M JfifnX' -

10 20 30 40 

Elapsed time, minutes 

50 60 

Figure 6-6. Typical emission concentration profiles for three types of gel coat 

spray guns. 

41 

<%\ 
"^ fe 

Regular 

gel 

coat/AAA 

ext. mix 

Regular 

gel coat/ 

HVLP int. 

mix gun 

Regular 

gel coat/ 

HVLP ext. 

mix gun 

Low VOC 

gel 

coat/AAA 

ext. mix 

Low VOC 

gel 

coat/AAA 

ext. mix 

Low VOC 

gel 

coat/AAA 

ext. mix 

Condition 

Figure 6-7. Emission reductions observed in the gel coat experiment 

(based on total emissions, or emission factors in grams per square meter). 

Ol 
P.55 

6.4 Resin Experiment Results 

Emission quantities for different resin application equipment are summarized and 

presented in Table 6-7. Nonspraying equipment (i.e., flow coater and pressure-fed roller) 

reduced total emissions by 31 to 33 percent when compared to controlled resin sprayup. As 

shown in Table 6-1, the statistical analysis indicates that total emissions between the flow coater 

and pressure-fed roller are not statistically significant at the 95 percent confidence level. 

Table 6-7. Summary of Emissions for Resin Application Equipment 

Type of 

equipment 

AAA spray gun 

(controlled 

spraying, 5 runs) 

Flow coater (3 

runs) 

Pressure-fed 

roller (3 runs) 

Materials 

used 

g 

6,670 

5,619 

5,096 

Total emissions 

g 

445 

306 

299 

Reduc. (%) 

BL 

31 

33 

Emission factor 

%AS 

17.5 

14.2 

15.3 

Reduc. (%) 

BL 

19 

13 

Emission factor 

g/g 

0.067 

0.055 

0.059 

Reduc. (%) 

BL 

18 

12 

Note: Material usage and emission quantities are the averages of the number of test runs for that equipment. 

BL = Baseline condition for emission reduction calculation. 

%AS = Percent of available styrene in resin. 

g/g = Gram of styrene emitted per gram of resin material used. 

The test plan originally called for six rans of controlled spraying. Accidentally, one of 

the six test runs was conducted in normal spraying. Table 6-8 compares the emission quantities 

for three types of application equipment to the normal spraying test ran. Controlled resin 

sprayup reduced total emissions by 30 percent when compared to normal (uncontrolled) resin 

sprayup. Flow coater and pressure-fed roller achieved 52 to 53 percent total emission reduction 

when compared to normal resin sprayup. 

Figure 6-8 shows the typical emission concentration profiles for various resin application 

techniques and equipment. Average styrene concentration during the application stage of the 

normal spraying test ran R10 was 88 ppm, which is higher dian the 60 ppm of the controlled .: 

spraying test ran R15. The flow coater and the pressure-fed roller took longer to complete the 

lamination but the magnitude of concentration profiles (less than 10 ppm) is much lower than 

that of resin sprayup. 

43 

4A*> 
P.56 

Table 6-8. Comparison of Emissions among Various Resin Application Equipment and 

Normal Spraying 

Type of 

equipment 

AAA spray gun 

(normal spraying, 

1 run) 

AAA spray gun 

(controlled 

spraying, 5 runs) 

Flow coater (3 

runs) 

Pressure-fed roller 

(3 runs) 

Transfer 

efficiency 

% 

80.5 

92.0 

97.3 

97.1 

Materials 

used 

g 

6,133 

6,670 

5,619 

5,096 

Total emissions 

g 

634 

445 

306 

299 

Reduc. 

(%) 

BL 

30 

52 

53 

Emission factor 

%AS 

27.1 

17.5 

14.2 

15.3 

Reduc. 

(%) 

BL 

35 

48 

44 

Emission factor 

g/g 

0.104 

0.067' 

0.055 

0.059 

Reduc. 

(%) 

BL 

36 

47 

43 

Note: Material usage and emission quantities are the averages of the number of test runs for that equipment 

BL = Baseline condition for emission reduction calculation. 

%AS = Percent of available styrene in resin. 

g/g = Gram of styrene emitted per gram of resin material used. 

Figure 6-9 shows the typical emission concentration profiles for various resin formulation 

test runs. The magnitude of the emission profiles decreases as the styrene content in the resin 

decreases or the styrene-suppressant content increases. Figure 6-10 compares emission profiles 

of the low-profile resin, neat BPO-catalyzed resin, and modified BPO-catalyzed resin. The neat 

and modified BPO resins had higher and longer concentration profiles man the low-profile resin 

because of higher styrene content or longer gel time. The BPO-catalyzed resin was formulated 

for filled application, but it was used in this testing without any filler. Fume silica was added to 

the BPO resin to keep the resin material on the mold until it was cured. 

Emission quantities for different resin formulations are summarized and presented in 

Table 6V9. Low-styrene resin reduced total emissions by 11 percent when compared to controlled 

resin sprayup. Styrene-suppressed resin with or without additional wax reduced total emissions 

from controlled resin sprayup by 36 to 40 percent. Emission reductions are even higher when the 

comparison is based on the normal spraying test ran. Statistical analysis indicates mat total 

emissions from styrene-suppressed resin with and without additional wax are not significantly 

different at the 95 percent confidence interval. The neat and modified BPO-catalyzed resins 

44 

AAt 
P.57 

F 

a. 

o. 

c 

o 

*-4 

cw a 

*-• C 

u o c o 

o 

160 

140 

1?0 

100 

80 

60 

40 

20 

;i L M I i i 

«" 

j Hfl 

I 

1 

\IJUL . 

Application ends 

! 1 

AAA spray gun, normal spraying technique (run R10) j 

: L-l| : : L_j : ^ - | n • r 

E a a 

c 

o 

e a 

u e o o 

e 

o 

c a o 

c 

o 

o 

10 20 30 40 50 60 

AAA spray gun, controlled spraying technique (run R15) j 

10 .20 30 40 

Application ends 

50 60 

10 20 30 40 

Application ends 

50 60 

Pressure-fed roller (run R3) j 

10 20 30 40 

Elapsed time, minutes 

50 60 

Figure 6-8. Emission concentration profiles observed for different 

resin application techniques and equipment. 

45 

4 S ~ 
P.58 

ujd 

a 

c 

o 

4W 

a h. 

C o 

o 

c 

o 

O 

F 

a 

a 

. 

c 

o 

CO 

c a 

a 

c 

o 

o 

E 

u. 

o 

S 

4f 

C 

0 Con 

E 

a 

c 

o 

5 

0) 

c o 

o 

E 

a a 

c 

o 

49* 

CB 

C 

0) 

c u o 

o 

160 

140 

120 

100 

80 

60 

40 

20 

0 

160 

140 

120 

100 

80 

60 

40 

20 

0 

160 

140 

120 

100 

80 

60 

40 

20 

0 

160 

140 

120 

100 

80 

60 

40 

20 

0 

160 

140 

120 

100 

RO 

60 

40 

20 

0 

Low profile resin, normal spraying technique (run R10) -

s: 

Low-profile resin, controlled spraying technique (run R15) L 

Low-styrene resin (run R14) 

^=5 = 

Styrene-suppressed resin (run R20) j — 

Styrene-suppressed resin plus wax (run Rl) j 

tr- iiiT n 

10 20 30 

Elapsed time, minutes 

40 50 60 

Figure 6-9. Typical emission concentration profiles for various resin formulations 

(applied by AAA spray gun). 

46 
P.59 

E a a 

« 

c 

o *s 

m 

o o 

c 

o 

u 

E 

a a 

c 

o 

c 

o 

o 

c 

o 

o 

Low profile resin, controlled spraying technique (run R15) 

BPO resin with thickener, fast gel time (run R25) 

10 20 30 40 

Elapsed time, minutes 

50 60 

Figure 6-10. Typical emission concentration profiles for low-profile, neat-BPO, 

and modified BPO resins (applied by AAA spray gun). 

47 

•<A^r 
& 

oo 

Type of resin (applied 

by controlled 

spraying, except as 

noted) ' 

Low-profile (normal 

spraying, 1 run) 

Low-profile 

(5 rans) 

Low-styrene (3 runs) 

Styrene-suppressed (3 

rans) 

Styrene-suppressed 

+wax (3 runs) 

Neat BPO resin (2 runs) 

BPO resin + thickener 

(2 runs) 

Note: Material usage and emiss 

Table 6-9. Summary 

Materials 

used 

g 

7,710 

6,670 

6,472 

6,258 

5,912 

6,792 

5,652 

ion quantities ai 

Total 

g 

634 

445 

395 

286 

266 

752 

512 

e the avc 

of Emissions for Various Resin Formulations 

emissions 

Reduction 

(%) 

BL 

30 

38 

55 

58 

-19 

19 

srages of t 

— 

BL 

11 

36 

40 

-69 

-15 

ie number 

Emission factor 

%AS 

27.1 

17.5 

17.3 

10.6 

10.6 

26.2 

21.3 

Reduction 

(%) 

BL 

35 

36 

61 

61 

3 

21 

— 

BL 

1 

39 

39 

-50 

-22 

of test runs for that equipmer 

Emission factor 

g/g 

0.104 

0.067 

0.061 

0.046 

0.046 

0.112 

0.091 

n. 

Reduction 

(%) 

BL 

36 

41 

56 

56 

-8 

13 

— 

BL 

9 

31 

31 

-67 

-36 

Rule 1162 static 

emission 

g/m2 

69 

69 

74 

54 

49 

161 

97 

Reduction 

BL 

BL 

-7 

22 

29 

-133 

-41 

BL = Baseline condition for emission reduction calculation. 

%AS = Percent of available styrene in resin. 

g/g = Gram of styrene emitted per gram of resin material used. 
P.61 

emitted more styrene than the low-profile resin. These results contradict the original assumption 

that resin catalyzed by BPO might reduce styrene emissions. Possible explanation for this 

situation is that the BPO resin was developed for filler application, not for neat resin sprayup and 

the gel time for BPO resin was longer than that of the low-profile resin. 

Figure 6-11 shows the overall emission reductions or increases observed in the resin 

experiment. The reductions or increases are calculated based on the total emission quantities 

presented in Tables 6-6,6-7, and 6-8 for each of the conditions. Using low-profile resin and 

controlled spraying as the baseline, emission reductions or increases for various equipment and 

materials are presented. Except for the BPO-catalyzed resin, all other resin formulations resulted 

in emission reduction when compared to the low-profile resin. 

Figure 6-12 shows the emission reductions or increases when using low-profile resin and 

normal spraying as the baseline. Higher emission reductions were achieved by flow coater, 

pressure-fed roller, low-styrene resin, and styrene-suppressed resin. If the normal spraying 

technique represents actual practices in the industry, Figure 6-12 shows the potential reduction 

that could be achieved by changing to flow-coater and pressure-fed roller and other low-styrene 

or styrene-suppressed resins. 

6.5 Comparison of Test Results with EPA AP-42 Emission Factors 

Emission factors derived from the test results are compared to relevant EPA AP-42 

emission factors in Table 6-10. These emissions factors are 1.6 to 2.5 times the respective 

midpoints of AP-42 emission factors. The implication of this finding is that current EPA AP-42 

emission factors for gel coat and resin sprayup and hand layup operations may underrepresent 

actual emissions for these operations. 

Table 6-10. Comparison of EPA AP-42 Emission Factors and Test Results (in % AS) 

Type of material and 

operation 

Gel coat sprayup (NVS) 

Resin sprayup (NVS) 

Resin sprayup (VS) 

Resin hand layup (NVS) 

AP-42 emission 

factor range 

26-35 

9-13 

3-9 

5-10 

AP-42 EF 

midpoint 

30.5 

11 

6 

7.5 

Emission factors from test 

results 

62.5 (normal spraying) 

56 (controlled spraying) 

54.2 (low-VOC gel coat, 

controlled spraying) 

27.1 (normal spraying) 

17.5 (controlled spraying) 

10.6 (styrene-suppressed 

resin, controlled spraying) 

15.3 (pressure-fed roller) 

Ratio 

2.0 

1.8 

1.8 

2.5 

1.6 

1.8 

2.0 

49 

^ - ^ 
© 

Ui 

50 -j 

40 

c O 

u 

0) 

ta. 

c 

o 

u 

3 

"O 

OJ 

Lm 

C 

,o "5 

in 

30 

20 

10 

0 

-10 

-20 

? -30 

-40 

-50 

-60 

-70 

+ .,.. 

Baseline 

TBStn/AArA'BTtt 

mix 

Baseline Baseline 

-resln/Flow—rostn/Pressure---

—coater fed-toller— 

Low VOC 

•7Bslnr~A"AAmix-gun. 

gun/Controlled 

Styrenepressed—re 

reainZ-AAA-ext 

mix oun 

BlpO-catalyz^d BfO-catalyzfed 

in/ AAA esin (slow -

mix gun 

«xr 

fl all/AAA e) t—fllalWAAA-exl 

mix gun 

-t-

"Bl 'O -catalyzed Styreneresin (fast—"suppressed -

mix gun resin/AAA ext 

Condition 

Figure 6-11. Emission reductions observed in the resin experiment: 

"controlled spraying" technique baseline 

(reductions based on total emissions, or emission factors in grams per square meter). 
60 

50 

40 

30 

ft S2 

c 

o 

o 

e 

c o 

« 20 -H 

•o 

o 

I 10 

CO 

E 

UJ 

-10 

-20 

-F- -1-

—Baseli 

resin/AAA ext 

Saseline— 

resin/Flow 

—coater— 

Baselineresin/Pressuretod-roller— 

- Low VOC 

resin/ AAA ext 

mix-gungun/Controlled 

—Styrene»— 

suppressed 

'esin/ 

mix gun 

-BPO-catalyzed Bfi 

resin/ AAA ext 

catalyz^d-BPO.catalyzed Styreocu 

resin (fast suppressed + 

AAA-ext mix-gun gjell/AAA ejt— -gel)/AAA-ext wax 

mix gun mix gun resin/AAA ext 

H 

Condition 

Figure 6-12 Emission reductions observed in the resin experiment: 

"normal spraying" technique baseline 

(reductions based on total emissions, or emission factors in grams per square meter). 
P.64 

6.6 Comparison of Emission Measurement Method and Mass Balance Calculation 

Method 

6.6.1 Pure Styrene Evaporation Test 

Three sets of pure styrene evaporation tests were conducted at Reichhold in June 1995. 

One set was conducted on June 5, the second set on June 7, and a final set on June 29. Within 

each set, there were several periods that different styrene evaporation rates were generated. The 

results of these different test rans are shown in Table 6-11 and Figure 6-13. The agreement 

between the emission measurements and the mass balance calculation method during the pure 

styrene evaporation runs was good. Table 6-11 shows that the average ratio of mass balance 

calculation method to emission measurements for these 15 rans was 0.99. Figure 6-13 indicates 

that the agreement between the mass balance calculation method and emission measurement 

method was within ±10 percent for 12 out of 15 runs. 

6.6.2 Comparison of Emissions Measured by Two Test Methods 

Mass balance measurements were compared with emission measurements during four 

experimental test runs and 55 official test rans at the Reichhold Chemicals facility. These 59 test 

runs can be separated into: 

4 Experimental runs 

12 Pilot test runs (involving gel coat spraying) 

18 Gel coat application rans 

21 Resin application runs 

59 Total rans 

These two methods for these 59 test runs are compared in Table 6-12 and Figure 6-14. 

Prior to June 22, the pilot and gel coat application test runs were made with only the 5-gallon gel 

coat supply container on the scale. The amount of material used in each test ran was calculated 

from the weight loss from the 5-gallon container. It was found that the pump system is a singleaction pump that withdraws material from the container only during the upstroke action. 

Therefore, there was a potential error in estimating the exact amount of material dispensed from 

the spray gun when the piston pump starts and ends at different positions. In this case, the 

amount of material in the pump system could not be accounted for by weighing the container 

only. Beginning in run G16, the project team member made sure that the pump staned and ended 

at the same position, so that the amount of material in the pump system remained the same at the 

beginning and the end of a test ran. This approach improved the accuracy of the mass balance 

calculation method. Table 6-12 indicates that the ratio between the mass balance calculation 

method and emission measurement method came close to 1.0 (indicating perfect agreement) 

much more consistently between test runs G16 and R2. 

52 

5^ 
Table 6-11. Comparison of Mass Balance Method and Emission Measurements for Pure Styrene Evaporation Tests 

O l 

u> 

Date 

(m/d/y) 

6/5/95 

6/5/95 

6/5/95 

6/5/95 

6/5/95 

6/7/95 

6/7/95 

6/7/95 

6/7/95 

6/7/95 

6/7/95 

6/29/95 

6/29/95 

6/29/95 

6/29/95 

Start Time 

(hnmin) 

15:46 

16:18 

16:43 

16:56 

17:09 

10:25 

10:42 

11:06 

11:14 

11:43 

11:58 

16:42 

16:52 

17:00 

17:32 

End Time 

(hr:min) 

15:59 

16:30 

16:55 

17:06 

17:19 

10:40 

10:57 

11:11 

11:35 

11:55 

12:05 

16:49 

16:59 

17:07 

17:45 

Emission rate 

by mass balance (MB) 

(g/min) 

9.2 

9.9 

17.4 

11.8 

12.3 

40.1 

15.3 

43.8 

9.7 

3.0 

34.1 

48.7 

21.3 

50.3 

29.5 

Average concentration 

by THC (FID) analyzer 

(ppm) 

8.4 

9.5 

14.1 

10.6 

11.8 

39.0 

14.8 

39.0 

9.4 

2.6 

34.0 

49.1 

21.5 

49.9 

31.4 

Exhaust 

flowrate 

(cfm) 

8961 

8961 

8961 

8961 

8961 

8924 

8924 

8924 

8924 

8924 

8924 

8646 

8646 

8646 

8646 

Emission rate 

by THC (FID) analyzer 

(g/min) 

9.3 

10.4 

15.5 

11.6 

13.0 

42.3 

15.8 

42.4 

9.9 

2.5 

36.9 

52.1 

22.8 

52.9 

33.3 

Average 

Emission 

ratio 

(MB/THC) 

0.99 

0.95 

1.12 

1.02 

0.95 

0.95 

0.97 

1.03 

0.98 

1.20 

0.92 

0.93 

0.94 

0.95 

0.89 

0.99 

100SSUM.XLS 
Rati

o of measured emissions 

(Mass balance/Method 25A) 

Tl 

t5' 

c 

3 

C?) I 

w 

O 

o 

3 

aS> CD 0 ) 

^H CO 

-* CO alan )per CD 3 

5?. 

ock t 

3 (hr: 

^ m a 3 > ® if I

s 

32 ° o a 

fi) N) 

S*. (II O > Z. • i?3 

- s r CO CO 

o 

3 CO 

3 CD tt CO 

c CD 

3 CD 

3 

i-+ CO 

• c_ 

c D CD NJ CD 

* _ i (0 (O Ol 

a c_ 

c 3 a> v l -• A (0 CO Ol 

• (_ 

c 3 (0 cn 

• • 

^ (0 (0 Ol 

99'd 
Table 6-12. ComDarison of M 

Date Time 

EXPERIMENTAL RUNS 

6/6/95 

6/6/95 

7/7/95 

7/7/95 

10:22 

14:55 

12:19 

14:12 

PILOT EXPERIMENT 

6/7/95 

6/8/95 

6/8/95 

6/8/95 

6/9/95 

6/9/95 

6/12/95 

6/12/95 

6/12/95 

6/13/95 

6/13/95 

6/13/95 

14:50 

10:01 

12:11 

14:40 

10:20 

14:45 

10:36 

13:47 

15:44 

10:37 

12:57 

15:21 

GELCOAT EXPERIMENT 

6/14/95 

6/14/95 

6/14/95 

6/15/95 

6/15/95 

6/15/95 

6/16/95 

6/16/95 

6/16/95 

6/19/95 

6/19/95 

6/19/95 

6/21/95 

6/21/95 

6/21/95 

6/22/95 

6/22/95 

6/22/95 

10:11 

13:46 

16:06 

11:38 

14:03 

15:59 

10:23 

12:49 

15:33 

10:36 

12:47 

15:23 

10:46 

13:18 

16:27 

11:14 

13:41 

15:55 

RESIN EXPERIMENT 

6/23/95 

6/23/95 

6/23/95 

6/26/95 

6/26/95 

6/26/95 

6/27/95 

6/27/95 

6/27/95 

6/28/95 

6/28/95 

6/28/95 

6/29/95 

6/29/95 

6/29/95 

6/30/9S 

6/30/95 

6/30/95 

7/5/95 

7/5/95 

7/5/95 

7/6/95 

7/6/95 

7/6/95 

7/7/95 

11:06 

14:30 

16:35 

10:42 

13:27 

16:05 

10:46 

13:14 

15:51 

10:21 

12:45 

15:20 

10:22 

12:20 

14:36 

10:14 

13:13 

15:51 

11:53 

14:02 

16:19 

10:12 

14:34 

16:41 

10:10 

Exhaust flow 

Test run U \ rate, cfm 

1 

RF1-EXP 

GF1-EXP 

EXP1 

EXP2 

PI 

P2 

P3 

P4 

P5 

P6 

P7 

P8 

P9 

P10 

P11 

PI 2 

GI 

G2 

G3 

G4 

G5 

G6 ' 

G7 

G8 

G9 

G10 

G11 

G12 

G13 

G14 

G15 

G16 

G17 

G18 

Rl 

R2 

R3 

R4 

R5 

R6 

R7 

R8 

R9 

R10 

R11 

R12 

R13 

R14 

R15 

R16 

R17 

R18 

R19 

R20 

R21 

R22 

R23 

R24 

R25 

9124 

9054 

8510 

8681 

8909 

8980 

8953 

8681 

8818 

8704 

8864 

8796 

8681 

9034 

8987 

8909 

8764 

8680 

'8563 

8610 

8609 

8633 

8916 

8887 

8819 

8752 

8866 

8700 

8804 

• 8739 

8660 

8775 

8820 

8722 

8710 

8683 

8399 

8563 

8495 

8495 

8613 

8543 

8358 

8501 

8471 

8501 

8566 

8495 

8633 

8495 

8521 

8457 

8637 

8471 

8419 

8589 

8661 

8492 

8658 

ass Balance Method and Emission Measurements 

Avg. net 

cone, ppm 

6.35 

7.30 

0.58 

4.48 

3.85 

7.14 

5.05 

7.39 

4.72 

6.21 

4.99 

7.53 

5.92 

5.11 

6.04 

6.02 

5.25 

5.30 

6.46 

3.41 

5.41 

5.13 

3.07 

4.97 

5.07 

5.14 

3.18 

2.74 

3.22 

2.85 

5.25 

3.00 

3.21 

3.19 

2.86 

3.52 

3.70 

3.17 

6.27 

3.65 

5.05 

5.16 

4.76 

7.49 

2.81 

2.18 

5.01 

5.04 

5.59 

4.03 

7.10 

4.07 

3.63 

3.51 

5.87 

5.74 

5.55 

3.96 

5.53 

Test run 

duration, min 

88.8 

56.2 

102.2 

31.2 

76.3 

68.2 

68.8 

66.8 

77.8 

76.3 

78.7 

68.2 

66.9 

70.0 

71.9 

72.3 

70.0 

70.0 

60.3 

75.7 

70.4 

71.2 

80.7 

70.5 

70.2 

69.6 

85.1 

85.0 

83.7 

87.5 

60.7 

85.0 

85.7 

82.4 

103.1 

81.3 

75.0 

83.8 

67.3 

78.0 

75.7 

71.8 

152.4 

81.5 

91.3 

95.2 

76.5 

75.1 

76.5 

79.1 

102.6 

69.3 

75.6 

74.7 

77.2 

75.9 

88.9 

78.0 

85.1 

Total emissions 

by THC. g 

631 

456 

62 

149 

322 

536 

382 

526 

397 

506 

427 

554 

422 

396 

479 

476 

395 

395 

409 

273 

403 

387 

271 

382 

386 

384 

294 

249 

291 

267 

339 

274 

298 

282 

316 

305 

286 

279 

440 

296 

404 

389 

743 

636 

267 

217 

403 

394 

453 

332 

762 

293 

291 

272 

468 

459 

524 

322 

500 

Total emissions 

by MB, g 

886 

478 

65 

152 

380 

607 

442 

415 

412 

506 

466 

499 

389 

457 

535 

442 

348 

406 

404 

227 

355 

410 

273 

472 

398 

360 

327 

346 

374 

332 

387 

. 302 

310 

286 

284 

335 

267 

280 

434 

302 

424 

361 

694 

607 

247 

203 

374 

366 

442 

.336 

732 

265 

262 

273 

428 

431 

488 

289 

488 

Average 

Emission ratio 

(MB/THC) 

1.40 

1.05 

1.05 

1.02 

1.18 

1.13 

1.16 

0.79 

1.04 

1.00 

1.09 

0.90 

0.92 

1.15 

1.12 

0.93 

0.88 

1.03 

0.99 

0.83 

0.88 

1.06 

1.01 

1.24 

1.03 

0.94 

1.11 

1.39 

1.28 

1.24 

1.14 

1.10 

1.04 

1.01 

0.90 

1.10 

0.93 

1.00 

0.99 

1.02 

1.05 

0.93 

0.93 

0.95 

0.93 

0.94 

0.93 

0.93 

0.98 

1.01 

0.96 

0.90 

0.90 

1.00 

0.91 

0.94 

0.93 

0.90 

0.98 

1.02 

55 

5 5 

MB THC.XLS 
OA 

a. a. t- <M 

UJ UJ X X 

+ + X-1-U 

u. u. 

cc o 

»-<NC>*in<or».eoo>0«-c>i «-cMC>*intor*.coo>0'-tNC'»^'in«or».oo ^Nn^intDMnmo^NrnfmoNomo^MoiTtu ) a.a.o.a.a.0.0.0.0 . — .-.- ooooooooo' -

'-'-'-'-'-'-'-' - ococococa:oca:oco:«-.-r-r-^-r-r-^-T-r-cMCNfM«Nc>icN 0.0.0. OOOOOOOO O tc oc ac oc tc tc tc tc tc cc tc tc cc tc tc tc 

Run Identification 

EXP = Experimental (resin 

and gel coat application) 

D P = Pilot (gel coat spraying) M G = Gel coat (spraying) R = Resin application 

Figure 6-14. Comparison of emission measurement methods. 
P.69 

Beginning in run R3, resin usage was measured by placing both the 5-gallon container 

and the entire piece of application equipment on the scale. This procedure avoided the need to 

make sure that the pump was returned to its initial position at the end of the run. With the pump 

and the gun on the scale, all material exiting the gun was directly measured. Figure 6-14 shows 

that the ratio between mass balance measurements was within +5 percent and -10 percent of 1.0 

for runs R3 through R25. 

Overall, the mass balance method and emission measurement method were within ±10 

percent for 43 out of 59 runs (i.e., 73 percent of the rans) and the two methods agreed to within 

±10 percent for all 25 resin runs (the last 25 rans). Table 6-12 shows that the average ratio 

between mass balance calculation measurements and emission measurements was 1.02. These 

results show that, on average, the two methods agreed to within 2 percent. 

Table 6-13 also shows that the mass balance/emission measurement ratio for the resin 

rans had a smaller standard deviation than the previous pilot and gel coat test runs. This 

comparison shows that correct measurement of the amount pf materia] used in a test ran 

improved the accuracy of the mass balance calculation method. These test results indicate that, 

when proper procedures are carefully followed, the mass balance calculation method can provide 

calculated emissions that are in good agreement with emission measurement using EPA Method 

25A and a total enclosure. 

Table 6-13. Comparison of Mass Balance and Emission Measurement Test Results 

(Testing at Reichhold, June-July 1995) 

Test 

designation 

Experimental 

Pilot 

Gel coat 

Resin. 

Total runs 

Weighted average 

Number of runs 

4 

12 

18 

25 

59 

Average ratio, 

(mass 

balance/emission 

measurement) 

1.13 

1.03 

1.07 

0.96 

1.02 

Standard 

deviation 

0.16 

0.12 

0.14 

0.05 

0.10 

57 

S3-
P.70_ 

1 

Chapter 7 

Data Quality Issues 

Overall data quality met or exceeded the objectives outlined in the Category ELT quality 

assurance project plan (QAPP). Specific QA activities are presented in the following sections. 

More detailed analyses or evaluations are provided in Appendixes D, G, and H (Volume U). 

7.1 Summation of Project QA Activities 

A quality assurance project plan, Pollution Prevention Technology Demonstration, 

Evaluation of Pollution Prevention Techniques to Reduce Styrene Emissions from Open Contact 

Molding Processes, Category III Quality Assurance Project Plan, was prepared by the RTI 

project team and submitted to EPA on April 28, 1995, for approval prior to the start of the 

proposed testing. Responses to comments from EPA were summarized in a memorandum from 

Emery Kong to Carlos Nunez dated May 25, 1995, which is considered an addendum to the 

QAPP. Both the QAPP and the addendum are included in Appendix A (Volume IT). 

As described in the QAPP, the following QA-activities were conducted as part of the project. 

The RTI project QA manager, Cynthia Salmons, and William Yeager conducted an internal 

technical system audit (TSA) of the project on June 9, 1995. 

No formal corrective action requests were necessary for this project. Minor deviations from 

the QAPP were documented in laboratory notebooks and data sheets, when necessary. Two 

major deviations were (1) the modification of BPO resin after it was found to have a long gel 

time and low viscosity and (2) the withdrawal of a water-emulsified resin from the test by the 

manufacturer. 

Other QA and QC activities during the course of this project included daily calibration of the 

high-precision scale with standard weights ranging from 1 g to 2,000 g (described in Section 5.2), 

periodic checks for scale drift by leaving a standard weight on the scale overnight, styrene 

evaporation experiments (described in Section 6.6.1), comparison of the total hydrocarbon 

analyzer's response to styrene cylinders with its response to the propane calibration cylinders 

(described in Appendix C), and a comparison of direct injection to the THC analyzer with 

delivery through the sampling line, as described in Appendix I (Volume H). 

7.2 RTI Internal Technical System Audit (TSA) Results 

The internal TSA found that the project activities were generally conducted in accordance 

with the QAPP and that results were carefully documented. More extensive calibrations of the 

THC analyzer we're performed than were described in the QAPP or the EPA method. The 

measurement point for the exhaust flow rate was approximately five or six diameters 

downstream of a bend, instead of the eight diameters recommended by the EPA method, but 

there was no reasonable way of correcting this. The maximum number of traverse points 

58 

S<b 
P.71 

suggested in EPA Method 1 for this type of situation was used. Checks for off-axis flow did not 

indicate a problem. The records for the total enclosure test indicated that there was considerable 

fluctuation in the hot wire anemometer readings and that a few of the flow velocity readings at 

the natural draft opening were slightly less than 200 ft/min, but this did not seem to present a 

problem, judging from the results of the styrene evaporation experiments. Due to the audit 

schedule, several aspects of the project were not observed during the TSA. These included 

sampling and analysis of the gel coat and resin, the styrene evaporation experiment, the 

demonstration that the spray booth meets the criteria for a total enclosure, the weekly traverse 

measurements, and the measurement of equipment delivery rate. Records of these activities were 

reviewed when possible. A memorandum documenting the TSA activities is included in 

Appendix H (Volume II). 

7.3 EPA Performance Evaluation 

EPA supplied RTI with a performance evaluation styrene standard gas cylinder, which RTI 

analyzed on July 7,1995. The results of this EPA performance evaluation are presented in 

Appendix I (Volume JJ). Using the THC analyzer and calibration standards, RTI predicted the 

styrene concentration in the EPA performance evaluation standard to be 30.4 ppm. The certified 

value of the styrene standard was 31.0 ppm by the Scott Specialty Gases. There was only a 2 

percent difference between the predicted and certified values. Therefore, the data quality 

objective for emission concentration measurement was met. 

59 

& AS 
P.72 

Chapter 8 

Conclusions and Recommendations 

8.1 Conclusions 

The results from the pilot experiment indicated that: 

Over the velocity range examined, 12 vs. 30 m/min (40 vs. 100 ft/min) linear air velocity 

had no significant effect on styrene emissions. 

Controlled gel coat spraying technique reduced total styrene emissions by 24 percent 

compared to normal spraying technique. 

Controlled spraying on the male mold reduced gel coat usage by 12 percent due to less 

overspray. 

Under normal spraying, 48 percent of total emissions was emitted during gel coat 

spraying; the remainder was emitted during curing. 

Under controlled spraying, 38 percent of total emissions was emitted during gel coat 

spraying; the remainder was emitted during curing. 

The results of the gel coat experiment indicated that: 

The low-VOC gel coat reduced total emissions by 28 percent when compared to the 

regular gel coat. 

The low-VOC gel coat required a higher air supply pressure and larger spray tip to 

achieve the same spray fan as the regular gel coat. 

The AAA and HVLP (internal and external catalyst mixing) gel coat spray guns made no 

difference in terms of total emissions. 

The results of the resin experiment indicated that: 

Controlled resin spraying emitted 30 percent less styrene than normal spraying 

technique. 

Flow coater and pressure-fed roller equipment resulted in 31 to 33 percent less styrene 

than controlled resin sprayup. 

Flow coater and pressure-fed roller equipment resulted in 52 to 53 percent less styrene 

than normal resin sprayup. 

Thirty-eight to 63 percent (average 50 percent) of total emissions was emitted during the 

resin application stage; the remainder was emitted during the wet-out rolling and curing 

stages. 

The low-styrene resin emitted 11 percent less styrene than the low-profile resin. 

• The styrene-suppressed resin emitted 36 percent less styrene than the low-profile resin. 

• The styrene-suppressed resin with 0.1 percent additional wax emitted 40 percent less 

styrene than the low-profile resin. 

60 

• 

CsP 
P.73 

• The BPO-catalyzed resin emitted more styrene than the low-profile resin because of 

higher styrene content and/or longer gel time. 

• For the BPO-catalyzed resin, a shorter gel time reduced total emissions. 

Other observations made from this testing were: 

• On an average of 55 official test rans and 4 experimental test rans, total emissions 

determined by emission measurements and the mass balance calculation method are in 

good agreement within 5 percent. 

• The mass balance calculation method could potentially be used to determine emissions 

from open molding processes. 

• Emission factors derived from the test results are 1.6 to 2.5 times the respective midrange EPA AP-42 emission factors; this implies that AP-42 emission factors for resin and 

gel coat sprayup may underrepresent actual emissions for these processes. 

8.2 Recommendations 

Based on the findings of this testing, the following recommendations are made to 

facilities using the open molding process: 

• Train operators to improve their spraying technique to reduce overspray, material wasted, 

and emissions. 

• Use nonspraying equipment when feasible to reduce emissions. -. 

• Use low-styrene or styrene-suppressed materials when feasible. 

• Reduce gel time when feasible to curtail emissions. • 

• Combine the effects of operator technique, materials, and application equipment to 

achieve the maximum emission reduction. 

• The mass balance calculation method and in-house personnel can be used to determine 

emission factors for materials and equipment. 

61 

(*( 
P.74 

TECHNICAL REPORT DATA 

(Please read Instructions on the reverse before completing) 

1. REPORT NO. 

EPA-600/R-97-018a 

3. RECIPIENT'S ACCESSION NO. 

4. TITLE ANO SUBTITLE 

Evaluation of Pollution Prevention Techniques to 

Reduce Styrene Emissions from Open Contact 

Molding Processes; Volume I, Final Report 

5. REPORT OATE 

March 1997 

6. PERFORMING ORGANIZATION CODE 

7. AUTHOR(S) 

Emery Kong, Mark Bahner, Robert Wright, 

Andrew Clayton 

and 

8. PERFORMING ORGANIZATION REPORT NO. 

9. PERFORMING ORGANIZATION NAME AND AOORESS 10. PROGRAM ELEMENT NO. 

Research Triangle Institute 

P.O. Box 12194 

Research Triangle Park, North Carolina 27709 

1 1. CONTRACT/GRANT NO. 

CR 818419-03 

12. SPONSORING AGENCY NAME ANO AOORESS 

EPA, Office of Research and Development 

Air Pollution Prevention and Control Division 

Research Triangle Park, NC 27711 

13. TYPE OF REPORT ANO PERIO0 COVERED 

Final; 4/94 -9/9 5 

14. SPONSORING AGENCY CODE 

EPA/600/13 

is. SUPPLEMENTARY NOTES APPC D pro j e c t officer is Geddes H. Ramsey, Mail Drop 61. 919/ 

541-7963. Volume II contains appendices. 

is. ABSTRACT rjj^g re p 0 r t gives results of a study to evaluate several pollution prevention 

techniques that could be used to reduce styrene emissions from open molding processe s in the fiberglass-reinforced plastics/composites (FRP/C) aiid fiberglass boat 

building industries. Styrene emissions using standard industry techniques, materials, and equipment were evaluated in a controlled environment and compared to a 

basline condition to determine the effects of these, pollution prevention techniques on 

styrene emissions. The study found that using controlled spraying (i. e., reducing 

overspray), low-styrene and styrene-suppressed materials, and nonatomizing application equipment can reduce styrene emissions by from 11 to 52%. Facilities should -

investigate the applicability and feasibility of these pollution prevention options to 

reduce their styrene emissions. The calculated emission factors were from 1.6 to 

2.5 times the mid-range AP-42 emission factors for the corresponding gel coat and 

resin application. These results indicate that facilities using AP-42 emission factors 

to estimate emissions in open molding processes are likely to underestimate actual 

emissions. 

17. KEY WORDS AN D DOCUMENT ANALYSIS 

DESCRIPTORS b.lDENTIFIERS/OPEN ENDED TERMS c. COSATI Field/Group 

Pollution 

Styrene Resins 

Emission 

Molding Techniques 

Fiberglass-reinforced Plastics 

Boats 

Pollution Prevention 

Stationary Sources 

Boat Building 

13B 

111. UJ 

14G 

13H 

UD 

13 J 

18. DISTRIBUTION STATEMENT 

Release to Public 

19. SECURITY CLASS (ThisReport) 

Unclassified 

2 1 . NO. OF PAGES 

71 

20. SECURITY CLASS (Thispage) 

Unclassified 

22. PRICE 

EPA Form 2220-1 (9-73) ""ST" 
U.S. ENVIRONMENTAL PROTECTION AGENCY 

Office of Research and Development 

National Risk Management Research Laboratory 

Technology Transfer and Support Division 

Cincinnati, Ohio 45268 

OFFICIAL BUSINESS 

PENALTY FOR PRIVATE USE S300 

AN EQUAL OPPORTUNITY EMPLOYER 

If your address is incorrect, please change on the above label 

tear off; and return to the above address. 

If you do not desire to continue receiving these technical 

reports, CHECK HEflf O . tear off label, and return it to the 

above address. 

Publication No. EPA- 600/R-97-018