p.1 

OAR Box 1392 

Prepped by Ollie Stewart 

Document Number: 

133) II-A-8 

Docket Number: 

A-94-52 

Printed 7/7/2008 9:45:59 AM Sheet 133 of 136 
United States Office of 

Environmental Protection Research and Development 

Agency Washington, DC 20460 

A-94-52 

P.2 

EPA-600/ft-96-I38 

November 1996 

Mi *\ 

* EPA Evaluation of Styrene 

Emissions From a 

Shower Stall/Bathtub 

Manufacturing Facility 

CH-=-CH2 

S--A-9 

p'p v '\V^ t 

- N ^V? ,\r

 s^'Cv^ fV %? "* ^ « 73? ,"?x ^^^-f

'!ww 

# . 

missions nventory ver si ght 

Prepared for Office of Air Quality Planning and Standards 

Prepared by Air aad Energy Engineering Research Laboratory 
P.3 

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 infbrmation 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-96-138 

November 1996 

EVALUATION OF STYRENE EMISSIONS FROM A 

SHOWER STALL/BATHTUB MANUFACTURING FACIUTY 

Prepared by: 

Larry Felix, Randy Merritt, and Ashley Williamson 

Southern Research Institute 

Environmental Sciences Research Department 

P. O. Box 55305 

Birmingham, AL 35255-5305 

EPA Contract Number 68-D2-0062 

Task No. 12, Phase 1 

Task Officer Bobby E. Daniel 

Air and Energy Engineering 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, D.C. 20460 

•. r 
P.5 

ABSTRACT 

Current EPA emission factors (AP-42) for styrene emissions from the production of polyester 

resin reinforced plastic products represent a composite of spraying and post-spraying emissions from 

shower stall/bathtub manufacturing plants that use compressed air-powered spray guns to apply 

catalyzed styrene resins to prepared molds. Because each step of manufacture (gel coating, first-stage 

spray lay-up, and second-stage spray lay-up) creates large surface areas from which volatile styrene 

monomer can evaporate, non-spraying emissions can constitute a large fraction of the styrene emitted 

to the atmosphere. Thus, it is of interest to quantify the level of non-spraying styrene emissions 

characteristic of this industry. 

In this study, emissions measurements were carried out at a representative facility (Eljer 

Plumbingware in Wilson, NC) that manufactures polyester resin reinforced shower stalls and bathtubs 

by spraying styrene-based resins onto molds in vented, open, spray booths. Styrene emissions were 

characterized for the three stages of manufacture by measuring styrene concentrations at the vents of 

spray booths used in each part of the process. In addition, styrene concentrations were measured at 

each ventilation fan exhaust. Emission levels were determined using EPA Method 18 to obtain 

integrated emissions samples and total hydrocarbon (THC) analyzers to measure continuous emissions 

levels during the EPA Method 18 sampling. 

Analysis of the EPA Reference Method data indicates that: (1) styrene monomer is the only 

volatile organic compound released in this process; (2) overall, approximately 4% of all material 

sprayed is lost to atmospheric emissions as styrene (approximately 19% of all styrene sprayed): and (3) 

emissions vary for each phase of manufacture, with post-spraying emissions of styrene (from curing 

molds) constituting a large part, approximately 29% of all emissions. 
P.6 

TABLE OF CONTENTS 

Abstract ii 

List of Figures iv 

List of Tables iv 

Acknowledgments v 

Metric to Nonmetric Conversions vi 

1. Introduction 1 

2. Project Description 4 

Experimental Approach 4 

Test Matrix 5 

Eljer Plumbingware Facility 6 

Sampling Locations 12 

3. Sampling and Analytical Procedures 15 

Plant Process Information 15 

EPA Method 18 Sampling 17 

Method 18 Sampling Equipment 18 

Method 18 Sampling Procedures 18 

Method 18 Styrene Analysis 19 

Sampling with THC Analyzers 21 

Volumetric Flow Rate Determination 24 

4. Results 25 

Recommendations for Future Sampling 37 

5. References 39 

Appendix A Quality Control Evaluation Report 40 

Summary 40 

Significant QA/QC Problems 41 

Data Quality 48 

Precision , 50 

Bias 52 

Completeness 53 

Representativeness 53 

Comparability 54 
P.7 

LIST OF FIGURES 

Figure Page 

1. Layout of the Eljer Plumbingware Facility 8 

2. Overall Arrangement for Roof Sampling Locations 13 

3. Equipment Arrangement Used for Sampling with THC Analyzers 23 

LIST OF TABLES 

Table Page 

1. Emission Factors for Uncontrolled Polyester Resin 2 

2. Eljer Plumbingware Test Matrix 7 

3. Plant Raw Material Consumption, June 15-17,1993 16 

4. Styrene Concentration and Emission Rate Summary for Eljer Plumbingware (June 1993) 30 

5. Styrene Emissions per Unit Area of Mold Sprayed, Eljer Plumbingware (June 1993) 31 

6. Determination of Non-Spray Booth Styrene Emission Rate 32 

7. Plant Raw Material and Styrene Usage, June 15-17,1993 32 

8. Styrene Emissions for Each Part of the Manufacturing Process 33 

9. Distribution of Styrene Emissions from Each Part of the Manufacturing Process, Including Styrene 

Emissions not Captured by Spray Booths 37 

A-1. Results of Analyses of EPA Performance Evaluation Audit Sample 45 

A-2. Results of Analyses of Matheson Calibration Gas 45 

A-3. GC-FID Calibrations Performed at Eljer Plumbingware 47 

A-4. Data Quality Indicator Goals for Critical Measurements Estimated in QAPP 50 

A-5. Data Quality Indicator Values for Method 18 and THC Measurements Made at 

Eljer Plumbingware 51 

IV 
ACKNOWLEDGMENTS 

The authors would like to thank J. N. Eason, Plant Manager at Eljer Plumbingware in Wilson, NC, 

for providing a site to carry out this evaluation and Rollie Nagel, Manager of Safety and Environmental 

Health at Eljer, for his support and help during the test. The authors would also like to thank EPA 

Task Officer Bobby Daniel of the EPA Air and Energy Engineering Research Laboratory for his help, 

support, and coordination throughout this work. 
P.9 

Metric to Nonmetric Conversions 

Readers more familiar with nonmetric units may use the following factors to convert to that 

system. 

Motrin MiiHipllor Vlolric Mnnmetrir 

kPa 

kPa 

°C 

I (1000 cm3) 

m 

m

2 

m

3 

kg 

1000 kg (metric ton) 

1450.38 

4.0145 

1.8T + 32 

0.26417 

3.2808 

10.7637 

35.3134 

2.2026 

1.1023 

psig 

in. H20 

°F 

gal. 

ft 

ft2 

ft3 

lb 

ton (short) 

VI 
P.10 

SECTION 1 

INTRODUCTION 

Current EPA emission factors (Table 1) for styrene emissions from the production of polyester 

resin reinforced plastic products represent a composite of spraying and post-spraying emissions (from 

curing molds) from shower stall/bathtub manufacturing plants that use compressed air-powered spray 

guns to apply catalyzed styrene resins to prepared molds.1 Because each step of manufacture creates 

large surface areas from which volatile styrene monomer can evaporate, post-spraying emissions can 

constitute a large fraction of the styrene emitted to the atmosphere. Thus, it is of interest to quantify 

the level of spraying and post-spraying styrene emissions characteristic of this industry. 

Shower stalls and bathtubs are among the many kinds of products fabricated from liquid 

polyester resin that has been extended with various inorganic filler materials and reinforced with glass 

fibers. These composite materials are often referred to collectively as fiberglass reinforced plastic 

(FRP) or "fiberglass". Depending on the size, shape, and intended use, any one of several 

manufacturing processes can be used for fabrication. For the manufacture of shower stalls and 

bathtubs, the preferred technique is spray lay-up or sprayup. Regardless, all of these processes 

involve the application of a liquid resin that is mixed with a catalyst to initiate polymerization. In 

polymerization, a liquid unsaturated polyester is cross-linked with a vinyl-type monomer, usually 

styrene, by the action of the catalyst. Common catalysts are organic peroxides, typically methyl ethyl 

ketone peroxide (MEKP) or benzoyl peroxide. Resins may contain inhibitors, to avoid self-curing during 

resin storage, and promoters, to allow polymerization to occur at lower temperatures.2,3 

In the production of fiberglass shower stalls and bathtubs, exhaust air from the spray booths 

used for mold-coating and plant ventilation air outlets represent the major point sources of VOC 

emissions. Thus, at a particular facility, the number of manufacturing steps that involve the spraying of 

styrene-based resins, the amount of styrene sprayed in each step of manufacture, and the amount of 

r 

\ 
P.11 

Table 1. Emission Factors for Uncontrolled Polyester Resin14 

PRODUCT FABRICATION PROCESSES (a) 

(100 x mass of VOC emitted/mass of monomer input) 

Process 

Hand lay-up 

Spray lay-up 

Continuous lamination 

Pultrusion(d) 

Filament winding(e) 

Marble casting 

Closed molding (g) 

I 

NVS 

5-10 

9-13 

4- 7 

4- 7 

5- 10 

1 - 3 

1 - 3 

Resin 

VS(b) 

2 - 7 

3 - 9 

1 - 5 

1 - 5 

2 - 7 

1 - 2 

1 - 2 

Emission 

Factor 

Rating* 

C 

B 

B 

D 

D 

B 

D 

Gel Coat 

NVS 

26 -35 

26 -35 

(c) 

(c) 

(c) 

(0 

(c) 

VS(b) 

8-25 

8-25 

(c) 

(c) 

(c) 

(0 

(c) 

Emission 

Factor 

Rating* 

D 

B 

(a) Ranges represent the variability of processes and sensitivity of emissions to process parameters. 

Single value factors should be selected with caution. NVS = nonvapor-suppressed resin. VS = 

vapor-suppressed resin. 

(b) Factors are 30-70% of those for nonvapor-suppressed resins. 

(c) Gel coat is not normally used in this process. 

(d) Resin factors for the continuous lamination process are assumed to apply. 

(e) Resin factors for the hand lay-up process are assumed to apply. 

(0 Factors unavailable. However, when cast parts are subsequently sprayed with gel coat, hand and 

spray lay-up gel coat factors are assumed to apply. 

(g) Resin factors for marble casting, a semiclosed process, are assumed to apply. 

* Emission factors developed from the results of facility source tests (B Rating), laboratory tests (C 

Rating), and through technology transfer estimations (D Rating).2 

<l~ 
P.12 

styrene that is volatilized during the spraying and curing of molds determines the amount of styrene 

emitted to the atmosphere. 

This study was undertaken to quantify styrene emission factors at a shower stall/bathtub 

manufacturing plant determined by the EPA to be a representative facility. Once styrene emissions 

were measured, the emissions measurements and raw material usage data from the plant were used to 

determine emission factors for each phase in the manufacturing process. 

Testing was carried out at Eljer Plumbingware, in Wilson, North Carolina and was part of a 

larger effort that also involved the evaluation of a pilot-scale liquid chemical scrubber for styrene 

removal. Styrene emissions measurements were originally scheduled for the week of June 14, 1993 

and the liquid chemical scnibber evaluation was originally scheduled for the following week. Because 

the plant was operating on a four-day production week during this time (Monday through Thursday), 

instead of the five-day production week that had been expected, emissions testing had to be extended 

through Monday, June 21,1993 to obtain a suitable set of emissions data. A full day of testing could 

not be carried out on Monday because portions of that day had to be devoted to preparing for the 

upcoming liquid chemical scrubber evaluation. 

Section 2 contains a detailed description of the facility and sampling locations. Detailed 

descriptions of the sampling methodology are presented in Section 3 and the results of this evaluation 

along with a discussion of these results are presented in Section 4. The quality assurance and quality 

control measures taken during this evaluation as well as the results of these measures are contained in 

the Quality Control Evaluation Report in Appendix A. 

3 

3 
P.13 

SECTION 2 

PROJECT DESCRIPTION 

EXPERIMENTAL APPROACH 

Styrene is an integral part of the industrial process that produces fiberglass bath tubs and 

shower stalls. In the first step of this manufacturing process, styrene monomer is mixed with polyester 

resin and a pigment to create a "gel coat" that is sprayed onto a previously prepared mold. Methyl 

ethyl ketone peroxide (MEKP) catalyst is added to the mix externally as it exits the compressed airpowered spray gun used to apply the mix to a mold. Molds are reusable and before each use the mold 

is waxed and coated with a mold-release agent that also helps to provide a high gloss to the finished 

product. In subsequent manufacturing steps, styrene and polyester resin are mixed with inert fillers and 

sprayed onto the previously coated mold along with chopped fiberglass. Between each application the 

fiberglass strands are compacted on the mold by manual rolling after which the coated mold is set 

aside while the resin is allowed to cure. Because curing is an exothermic process, succeeding 

manufacturing steps are usually not earned out until the coated mold has cooled. Fiberglass provides 

structural support for the finished article, while the cross-linked styrene and polyester resin act as a 

glue to hold the matrix together, and the inert fillers provide additional structural support and can also 

provide fire retardant properties. The final stage of manufacture is to separate the finished fiberglass 

product from the mold, and prepare it for shipment 

The purpose of this project is to develop quantitative emission factors specific to a spray layup 

polyester resin shower stall and bathtub manufacturing process. To develop these emission factors, 

styrene emissions were quantified from every point of air exhaust to the atmosphere at a fiberglass 

shower stall and bathtub manufacturing plant located in Wilson, North Carolina. Specifically, the 

following information was required to develop quantitative emission factors for styrene: 

• Determination of the emission rate of styrene emitted from process exhaust vents 

during normal production. 

*<-
P.14 

Determination of the emission rates of any fugitive styrene emissions during storage, 

transfer or mixing of the resin or gel coat by process material balance. 

Relation of emission rates of styrene to the amount of raw materials used and to the 

number of units produced by collecting process data during tests of process exhaust 

vents, measuring the time required to complete each unit, determining material 

balances for the production process, and by computing emission factors for vents and 

for fugitive emissions (weight of emissions per weight of material processed). 

With the exceptions noted below, two methods were used to measure styrene emissions. A 

heated TedlarTM bag sampler was used to obtain an integrated sample of the contaminated air exiting a 

representative point in each process exhaust vent (EPA Reference Method 18).5-

6

 Concurrently, 

styrene emissions were measured on a continuous basis using a Total Hydrocarbon Analyzer (THC) 

equipped with Flame Ionization Detectors (FIDs). Sample times ranged from 40 to 45 minutes, typically 

the time required to spray eight to ten molds. Sample times were dictated by the plant production rate 

and the time available for sampling during a particular period of spraying. 

Test Matrix 

Fifteen locations were sampled for styrene. Eleven of these locations were roof vents from 

spray booths (seven booths were in use throughout the evaluation while the other four were used only 

for building ventilation), while the four other locations were exhaust fans located on the side of the 

building. Three exhaust fans were devoted to area ventilation for the building and one exhaust fan was 

used to provide ventilation for the resin mixing room. 

As noted in Section 1, because production was carried out only four days per week (Monday 

through Thursday) instead of five days per week, one less day of testing was available than was 

scheduled. The original test schedule called for one day of setup (Monday), four days of testing 

(Tuesday through Friday), a weekend off, and the next week to be devoted to the evaluation of a pilotscale liquid chemical scrubber with Monday being a setup day. Unfortunately, it was not known that the 

plant was on a four-day production schedule until Monday, June 14. On that day, after consulting with 

the EPA Project Officer, it was decided that to obtain the maximum amount of reliable data during the 

week of June 14, EPA Method 18 sampling would be focused on the seven active spray booths and 

that styrene emissions from non-active booths and building exhaust fans (including the resin mixing 

5 
P.15 

room exhaust fan) would be measured with THC analyzers only. Because these measurements could 

not all be completed during the week of June 14, THC sampling of exhaust fan emissions was carried 

out on Monday of the following week (while preparations were underway to begin the evaluation of the 

liquid chemical scrubber). No more time could be taken from the evaluation of the liquid chemical 

scrubber because the following week was also to be a four-day work week with one less day of 

sampling than was expected. With the permission of the EPA Project Officer, headspace samples from 

styrene storage tanks were also not taken because the vats of styrene containing mix are open at their 

tops, so it was decided that a sample would be taken from the air exiting the resin mix room. Table 2 

shows the sampling and analytical test matrix that was used for this testing. Details of the sampling 

and analytical procedures used for this evaluation are presented in Section 3. 

ELJER PLUMBINGWARE FACILITY 

The Eljer Plumbingware facility, diagrammatically shown in Figure 1, is located in Wilson, North 

Carolina. In this figure the location of each process vent is indicated. There are a total of fifteen vents 

where air is exhausted. Eleven of these vents are from spray booths, seven of which were used for 

spraying during this test. Three large fans shown on Rgure 1 are used to provide a continuous source 

of outside ventilation air to the plant. During this testing, three booths were not used (marked as 

"unused" in Figure 1) and the air exhaust on these booths was closed off (normally, all fifteen vents are 

used throughout the day). Ventilation air is turned on approximately 15 minutes before the workday 

starts and is shut off approximately fifteen minutes after the workday ends. 

G» 
P.16 

Table 2. Eljer Plumbingware Test Matrix 

Sample Location 

Gel Coat Booth #1 

Gel Coat Booth #2 

Gel Coat Booth #3 

Lay-Up Booth #1 

Lay-Up Booth #2 

Lay-Up Booth #3 

Lay-Up Booth #4' 

Lay-Up Booth #5' 

Lay-Up Booth #6' 

Back-Up Booth #1 

Back-Up Booth #2' 

Exhaust Fan #1 

Exhaust Fan #2 

Exhaust Fan #3 

Exhaust Fan, Resin 

Mixing Room 

No. of Runs 

1 

4 

5 

4 

4 

6 

2 

3 

3 

1 

4 

5 

1 

3 

3 

1 

3 

3 

2 

1 

2 

1 

2 

1 

2 

4 

5 

2 

1 

1 

1 

1 

1 

1 

1 

1 

- 1 

Sample Type 

Gas Velocity 

Styrene 

Sytrene/Gas Velocity 

Gas Velocity 

Styrene 

Styrene/Gas Velocity 

Gas Velocity 

Styrene 

Styrene/Gas Velocity 

Gas Velocity 

Styrene 

Styrene/Gas Velocity 

Gas Velocity 

Styrene 

Styrene/Gas Velocity 

Gas Velocity 

Sytrene 

Styrene/Gas Velocity 

Gas Velocity. 

Styrene/Gas Velocity 

Gas Velocity 

Styrene/Gas Velocity 

Gas Velocity 

Styrene/Gas Velocity 

Gas Velocity 

Styrene 

Styrene/Gas Velocity 

Gas Velocity 

Styrene/Gas Velocity 

Gas Velocity 

Styrene 

Gas Velocity 

Styrene 

Gas Velocity 

Styrene 

Gas Velocity 

Styrene 

Procedure 

Method 1-2 

Method 18 • 

THC Analyzer 

Method 1-2 

Method 18 

THC Analyzer 

Method 1-2 

Method 18 

THC Analyzer 

Method 1-2 

Method 18 

THC Analyzer 

Method 1-2 

Method 18 

THC Analyzer 

Method 1-2 

Method 18 

THC Analyzer 

Method 1-2 

THC Analyzer 

Method 1-2 

THC Analyzer 

Method 1-2 

THC Analyzer 

Method 1-2 

Method 18 

THC Analyzer 

Method 1-2 

THC Analyzer 

Velocity Meter 

THC Analyzer 

Velocity Meter 

THC Analyzer 

Velocity Meter 

THC Analyzer 

Velocity Meter 

THC Analyzer 

Sample 

Duration 

30 min. 

45 min. 

45 min. 

30 min. 

45 min. 

45 min. 

30 min. 

45 min. 

45 min. 

30 min. 

45 min. 

45 min. 

30 min. 

45 min. 

45 min. 

30 min. 

45 min. 

45 min. 

30 min. 

33 min. 

30 min. 

12 min. 

30 min. 

10 min. 

30 min. 

45 min. 

45 min. 

30 min. 

10 min. 

30 min. 

18 min. 

30 min. 

33 min. 

30 min. 

31 min. 

30 min. 

14 min. 

Analysis Method 

Pitot 

GC/FID 

THC/FID. Pitot 

Pitot 

GC/FID 

THC/FID. Pitot 

Pitot 

GC/FID 

THC/FID. Pitot 

Pitot 

GC/FID 

THC/FID, Pitot 

Pitot 

GC/FID 

THC/FID. Pitot 

Pitot 

GC/FID 

THC/FID. Pitot 

Pitot 

THC/FID. Pitot 

Pitot 

THC/FID. Pitot 

Pitot 

THC/FID. Pitot 

Pitot 

GC/FID 

THC/FID. Pitot 

Volumetric 

THC/FID 

Volumetric 

THC/FID 

Volumetric 

THC/FID 

Volumetric 

THC/FID 

Volumetric 

TCH/FID 

No active spraying was carried out in these booths during the test period. Used lor ventilation 

only. 

1 
P.17 

EXHAUST 

FAN t 

RESIN 

MIXING 

ROOM 

SERVICE 

ACCESS 

J. 

•190 ft.-

FIBERGLASS 

ROVING FEEDER 

H 

T 

8ACX-UP 

BOOTH #2 

VAN 

MOBILE 

LAB 

TRAILER 

GELCOAT 

STAGING 

AREA 

T 

11511 

-L 

l L@f 

BACK-UP 

BOOTH I 

LAY-UP 

BOOTH M 

^ LAY-UP 

Y BOOTH #S 

d l; 

r LAY-UP 

BOOTH M 

d§r 

LAYUP 

BOOTH «3 

LAY-UP 

BOOTH n da 

LAY-UP 

BOOTH »1 

., GELC GEL COA C ' PUMPS 

MOLD SEPARATING 

STATION 

'/ 

265 ft. 

MOLD REPAIR SHOP 

ROOF EXHAUST. 

VENT STACK 

EXHAUST FANS 

cz> 

T T 

« J 1 

Figure 1. Layout of Eljer Plumbingware Facility 
P.18 

During this evaluation, the workday started at 0700. One-half hour breaks in production 

occurred at 1000 hours (morning break) and 1200 hours (lunch break). The workday ended at 1400. 

Thus, during a typical day of testing, all ventilation fans ran for 7.5 hours while three periods of mold 

spraying took place: 0700 to 1000, 1030 to 1200, and 1230 to 1400, accounting for six hours of actual 

spraying. 

Each stage of manufacture except for mold separation or "pulling" is carried out in a spray booth. 

At the Eljer facility the spray booths were not constructed in place but are prefabricated units 

manufactured by Binks, Inc. The available volume in each spray booth is comprised of a height of about 

3.05 m (10 ft), a width of about 4.11 m (13.5 ft), and a depth of about 3.66 m (12 ft). The booths are 

approximately 1 m deeper but 3.66 m back from the mouth of the booth an expanded metal grate is 

mounted across the width and height of the booth on which a large sheet of air conditioning-type filter 

material is mounted. The filter material is usually changed every other day. While these filters appear 

quite dirty when they are removed, the resuits of velocity traverses made at the exit vent of a booth before 

and after the filter material was replaced showed that air flow was essentially unaffected by a clean or 

dirty filter. 

Each spray booth is continuously vented with air from the interior of the plant that is pulled into 

the booth entrance, through the filter mat, and a five-blade fan unit mounted approximately 2 m below the 

roof of the building. Air pulled into the fan exits vertically through a 0.91 m (3 ft) diameter stack mounted 

on the roof of the facility. Each exhaust fan has a nominal rated flow of 411 m3/min (14,500 acfm). 

During testing, fan capacities of from 353.5 to 427.9 m3/min (dry, referenced to 20°C) were measured. 

There are three distinct manufacturing steps that are required to produce a fiberglass shower 

stall or bath tub at the Eljer facility. First, a prepared mold is mounted on a cart and wheeled into one of 

the three gel coat spray booths located near the mold repair shop. In the spray booth, the mold and cart 

are designed to slide onto the ann of a permanently mounted pedestal assembly that can be hydraulically 

elevated above the floor of the spray booth. The mold and cart are also designed to rotate on the arm of 

the pedestal so that all parts of the mold are accessible for spraying. This mounting system is duplicated 

in every spray booth at the Eljer facility. 

T 
P.19 

Gel coat is a mixture of styrene monomer, polyester resin, and pigment (chromatographic 

analysis, 32.2% styrene) and is purchased as a prepared mix in 55 gallon drums. During this test, the gel 

coat mix contained no additive to suppress styrene vapor emissions. At the time of this test at least four 

colors of pigment were observed: white, off white, pink, and blue. However, plant records only keep track 

of white and colored gel coat usage. 

About two to three minutes are required to coat a bath tub mold (approximately 2.5 m2) with gel 

coat and about five minutes are required to coat a large shower stall mold (7-8 m2) with gel coaL After 

spraying is completed, the mold is oriented upright and the pedestal is lowered until the wheeled cart 

mounted to the mold contacts the floor. The mold and its attached cart are then wheeled out of the booth 

to await the next stage of manufacture. Between each stage of manufacture the coated mold is set aside 

to cure and harden for about an hour. Curing generates heat, so there is a time interval between 

sprayings to allow the coated mold to cool. 

The second stage of manufacture is called the "first lay-up' or "initial laminating" step and occurs 

in two parts. In this stage, the mold is conveyed to one of the first lay-up booths and, as with the first 

step of manufacture, mounted on a pedestal and prepared for spraying. The mix sprayed in this stage is 

composed of a powdered inert filler added to a mixture of styrene monomer and polyester resin to form a 

slurry that contains approximately 50% solids (chromatographic analysis, 21.4% styrene). The lay-up mix 

is prepared in the resin mix room shown in Figure 1 and is pumped to the point of delivery. 

Two coats of this slurry are sprayed onto the mold and during the spraying operation, chopped 

fiberglass roving (3 to 4 cm long) is also blown at about a 30° angle into the stream of spray as it exits 

the spray nozzle. The spray mixes with the strands of chopped fiberglass and forms a entangled mat of 

resin impregnated fiberglass on the surface of the mold. The inert filler and the chopped fiberglass help 

provide structural support to the finished product Between sprayings, the mold is left in the booth while 

from two to four workers quickly compact and flatten the matted surface of the mold with small, hand-held 

rollers. After the second spraying, the mold is wheeled from the booth and rolled again. The total time 

for both sprayings usually takes two to three minutes and rolling can take another one to two minutes. 

However, because one person is used to operate the sprayer in the three lay-up booths, the time between 

sprayings averages from seven to ten minutes while other molds are being sprayed in the other lay-up 

10 
P.20 

booths. As with the first stage of manufacture, this step is brief and requires only three to five minutes to 

complete. When this step is completed the coated mold is once again set aside to cure. 

The third, and final, spraying step is called the "second lay-up" or "back up" step and takes place 

in one of the two second lay-up booths shown in the upper left comer of Figure 1 (Back-Up Booth #1 or 

Back-Up Booth #2). During this evaluation, only back-up booth #1 was used. Like the lay-up step, this 

operation is carried out in two parts with two spraying steps. In this step, a blend of powdered inert filler 

(incorporating a fire retardant) is added to a mixture of styrene monomer and polyester resin to form a 

slurry that is contains approximately 50% solids (chromatographic analysis. 20.9% styrene). As with the 

lay-up mix, the back-up mix is prepared in the resin mix room shown in Figure 1 and is pumped to the 

point of delivery. 

The back-up mixture is also sprayed with chopped fiberglass fibers and forms the final two layers 

of the product. As with the second stage of manufacture, the mold is first moved into the back-up booth 

where a fresh layer of the back-up slurry/chopped fiberglass mix is sprayed onto the mold. The mold is 

then moved out in front of the booth where precut chipboard and corrugated paper supports are pressed 

and molded into the wet slurry/fiberglass layer on the sides and bottom of the mold. The mold is then 

moved back into the booth for a final spraying that covers all of the chipboard and heavy corrugated 

paper supports. After the mold emerges from the back-up booth for the second time it is manually rolled 

and set aside to cure for the last time. 

Two molds are usually worked on at a time. Thus, while the supporting layer of chip board and 

corrugated paper is applied to one mold, another mold is being sprayed with its first layer of back-up mix. 

When the second mold is moved back into the booth for its final spraying, the first mold has its supporting 

layer of chip board and corrugated paper applied. This step is brief and requires only seven to ten 

minutes to complete two molds. 

The last phase of manufacture is "pulling" or separation of the mold from the completed shower 

stall or bath tub. After the finished fiberglass piece is trimmed and inspected it is prepared for shipment. 

During the time of the emissions testing, on a daily basis, this facility consumed approximately 

500 kg gel coat mix and approximately 4000 kg of lay-up mix and back-up mix. On the basis of a fourday work week, which was typical for that time, and a 50-week work year, yearly gel coat mix 

11 

/( 
P.21 

consumption would be approximately 100,000 kg, and yearly consumption of lay-up and back-up mix 

would be approximately 800,000 kg. 

SAMPLING LOCATIONS 

Two types of sampling locations were encountered in this evaluation. The first type of sampling 

location was located on the roof of the facility and consisted of a 0.91 m (3 ft) diameter stack that 

extended approximately 1.5 m (5 ft) above the surface of the roof. Eleven such stacks are used to 

convey vent air to the outside from the eleven spray booths with operating exhaust fans. Moveable split 

circular doors are positioned approximately 0.3 m (1 ft) below the top of each stack. These split doors are 

designed so that when the exhaust fan feeding the stack is turned on, the doors fold together, up and out 

of the way, kept open by the outwardly moving air stream. When the exhaust fan feeding the stack is 

turned off, the doors close to prevent the entrance of rain or vermin. The actual exhaust fan for each 

stack is located approximately 2 m (6.6 ft) below roof level. The fans typically have five blades. Figure 2 

shows the overall arrangement for one of these sampling locations. 

As Figure 2 shows, because of the eductor-type shroud that is mounted near the surface of the 

roof, and because of the split door covers, it was necessary to conduct all sampling from as close to the 

top of the roof as was. possible. Below the eductor-type shroud and above the rain cap, two small 2.5 cm 

(1 in.) holes were drilled in the side of each stack at a 90° angle to each other, just large enough to allow 

the entry of an s-type pitot or Method 18 sampling probe. Because the vents were at essentially 

atmospheric pressure, no significant amount of air entered or was lost through these small ports. The 

ports were covered over at the end of the evaluation. 

The second type of sampling location was at the exhaust of a three or four-bladed exhaust fan 

on the side of the building shown in Figure 1, about 3 m (10 ft) above the ground. These fans were 

protected from the elements by horizontal louvers on the discharge side of the fan that close when the fan 

is turned off, but are kept open by air exiting the fan when it is turned on. Because the louvers tended to 

oscillate from nearly fully open to approximately 75% open while they operated, the louvers had to be held 

fully open to be able to measure the velocity of the air exiting any one of these fans. Even so, because 

these fans operate with no stack to straighten or direct their exhaust, air flow is very uneven. 

12 
WBmm 

Weather Flaps 

Held Open by Air Flow 

77 

' / 

^ J 17 ? 

icmisemitamxrwxamimMmimtmm 

Sampling Port 

ROOF LINE 

AIR FLOW 

-3 ft. 

Figure 2. Overall Arrangement for Roof SampOng Locations. 

13 

I S 
P.23 

Three exhaust fans were located on the northwest side of the building. Another fan of this type was 

located on the southeast side of the building and was used to ventilate the resin mixing room. Air velocity 

was measured with a direct reading velocity meter that was checked against the s-pitot used at the spray 

booth exhausts for air flow measurement. 

14 

1 * 
P.24 

SECTION 3 

SAMPLING AND ANALYTICAL PROCEDURES 

The sampling and analytical procedures used for this evaluation incorporated the most recent 

revisions of the published EPA methods, where applicable. In this section, descriptions of each sampling 

and analytical method that was used in this evaluation are presented. 

In order to meet the test objectives in an expedient manner, a trailer housing a mobile laboratory 

was set up on site. All gas chromatographic (GC) analysis of the integrated Tedlar bag samples for 

styrene were performed there. This trailer was also equipped for sampling two separate emissions 

sources with THC monitors.7 The trailer was supplied by DEECO, Inc. of Cary, NC who also provided 

personnel to conduct the Method 18 sampling and GC-FID analysis. The mobile laboratory was located 

on the northeastern side of the building, outside, next to the gel coat staging area. In addition to the 

mobile laboratory, a second vehicle, a van, was equipped for THC sampling and was used in this 

evaluation and for the evaluation of a liquid chemical scrubber during the week following this testing. The 

van was located in front of the mobile laboratory, along the northeastern side of the building. 

Electrical power was provided to the mobile laboratory from plant service (a 220 VAC line) 

through cabling supplied by Southem Research. Electrical power was connected and disconnected by a 

local electrical contractor familiar with the plant power system. Electrical power to the van for the THC 

analyzers and ancillary electrical equipment was obtained from one leg of the 220 VAC line that fed the 

mobile laboratory. Power for roof top sampling was carried by heavy-duty extension cords from a power 

distribution center installed by the electrical contractor for the duration of the test. 

PLANT PROCESS INFORMATION 

Eljer Plumbingware provided plant raw material usage records for the three days during which 

spray booth samples were taken. These records are reproduced in Table 3. These data gave raw 

material usage in terms of kilograms of product used in each phase of manufacture and in 

15 
P.25 

Table 3. Plant Raw Material Consumption, June 15-17, 1993" 

Item 

Gel Coat Mix (32.2% Styrene") 

Area Sprayed 

White Mix 

Colored Mix 

MEKP 

Total 

Lay-Up Mix (21.4% Styrene") 

Area Sprayed 

Resin (incl. styrene) 

Inert Filler 

Pigment 

Vapor Suppressant 

MEKP 

Fiberglass Roving 

Total 

Back-Up Mix (20.9% Styrene") 

Area Sprayed 

Resin (incl. styrene) 

Inert Filler 

Pigment 

Vapor Suppressant 

MEKP 

Fiberglass Roving 

Total 

Units 

m

2 

kg 

kg 

kg 

kg 

m

2 

kg 

kg 

kg 

kg 

.kg 

kg 

kg 

m

2 

kg 

kg 

kg 

kg 

kg 

kg 

kg 

6/15/93 

664.6 

290.8 

197.3 

7.3 

495.3 

640.5 

958.0 

1272.3 

1.8 

5.0 

27.7 

306.2 

2571.0 

640.5 

775.2 

1166.6 

1.4 

4.1 

29.0 

163.3 

2139.6 

6/16/93 

646.0 

295.7 

220.4 

7.7 

523.9 

642.1 

909.9 

1208.8 

1.4 

4.5 

26.3 

306.2 

2457.1 

642.1 

721.2 

1085.4 

1.4 

3.6 

27.2 

161.9 

2000.8 

6/17/93 

653.0 

286.2 

226.8 

7.7 

520.7 

652.1 

923.5 

1226.5 

1.4 

4.5 

26.8 

349.3 

2532.0 

652.1 

716.2 

1077.7 

1.4 

3.6 

26.8 

165.6 

1991.3 

Results for sample obtained on 6/22/93 at 1020 hours. 

16 
P.26 

kilograms of product used per square foot of mold sprayed. The total area of mold that was sprayed in 

each phase of manufacture was also provided as part of the daily record. 

To relate the emissions data taken at each active spray booth to raw material usage, records 

were kept of the area of molds that were sprayed in each active booth while sampling was underway. 

Because plant production records do not track where a mold was sprayed, portable video cameras were 

used to record the spraying activity that took place in a particular spray booth while the air exhausted from 

that booth was being sampled. Afterwards, by inspecting the video record, mold types could be identified 

and, with the help of catalog data sheets provided by Eljer Plumbingware, the total mold area sprayed 

could be determined for each period of sampling. In this way, styrene emissions per unit area of mold 

sprayed could be determined to compare with styrene use per unit area of mold sprayed. 

Unfortunately, one video camera failed partway through the test and two data sets from the same 

spray booth were lost (gel coat booth #2). Data from two other spray booths were lost when one camera 

was inadvertently pointed at the wrong spray booth (lay-up booth #3 instead of lay-up booth #2) and when 

plant production was shifted away from one booth so that no molds were sprayed during the time that 

booth was sampled (gel coat booth #1). 

EPA METHOD 18 SAMPLING 

Samples for on-site analysis of styrene content were collected using EPA Method 18, according to 

Section 7.1.1 of the method: Integrated Bag Sampling and Analysis, Evacuated Container Sampling 

Procedure.6 Time integrated samples were collected for a typical collection time of 45 minutes by drawing 

spray booth exhaust air into new 15 liter Tedlar or Teflon bags at constant sampling rates. With one 

exception, samples were collected in triplicate or quadruplicate at the locations described in Table 2. 

Each sample was analyzed on site by gas chromatography utilizing a flame ionization detector (GC/FID). 

Stack parameters of velocity and flow rate were determined by Methods 1-2. 

17 

\ ^ t 
P.27 

Method 18 Sampling Ftiuioment 

Styrene-containing samples of spray booth exhaust were collected in evacuated Tedlar and Teflon 

bags. The sampling train consisted of a heated Teflon probe and sampling line, heated leakproof rigid 

sampling container, and VOST-train sampling boxes with sampling pump and dry gas meters. Constant 

sampling rates were used, typically 0.25 liter/minute. To prepare for sampling, Tedlar or Teflon bags were 

blanked with dry air, evacuated, and sealed into the sampling containers. 

All bags were heated to 11°C (20°F) above ambient to minimize styrene loss. This temperature 

was chosen because rooftop temperatures averaged about 38°C (100°F) during most testing. The Teflon 

probes and sampling lines were also maintained at 49°C (120°F). Thus, bags were evacuated, installed 

in the sampling containers, and preheated to 49°C (120°F) before being taken to the sampling location. 

Before, during, and after sampling, and until they were analyzed, the 15 liter Tedlar bags were maintained 

at 49°C (120°F) within the sampling container. 

Method 18 Sampling Procedures 

The order of testing was determined by spray booth availability and distance from the mobile 

laboratory. Testing started with gel coat booths 1 through 3 which were the furthest away from the mobile 

laboratory. Lay-Up booths 1 through 3 were sampled next, then Back-Up booth #1 and any other spray 

booths that needed to be repeated. 

To prepare for sampling, in the mobile laboratory, evacuated Tedlar or Teflon bags were placed in 

the rigid, leakproof sampling container and the inlet of the bag was connected to one of two Swagelock® 

fittings mounted in the top of the container. The lid was placed on the container and sealed. At this point 

the heating jacket on the container was allowed to bring the container and its bag to 49°C (120°F). When 

the container had stabilized at 49°C (120°F), it was transported to the roof of the facility. On 

the roof, each sample container was leak checked, and the heated probe and sample line were attached 

to the sample container. The probe was placed at a point where the local velocity was approximately > 

18 
P.28 

equal to the average velocity measured for the stack, as close to the center of the stack as was possible, 

and the bag and sample line were conditioned with stack gas by filling and evacuating the bag three times 

in succession. Sampling began and pertinent times and sampling parameters were entered on the 

appropriate run sheet. Sampling continued for 45 minutes with the exception of four runs that were cut 5 

minutes short because spraying in a particular booth had temporarily ceased. 

When sampling was completed, the heated sampling container and Tedlar or Teflon bag was 

returned to the mobile laboratory for analysis. For analysis, contents of the heated bag were sampled 

directly by the GC/FID in the mobile laboratory within one to two hours after sampling was completed. 

The bag was then removed and discarded while a new bag was fitted into the rigid sampfe container and 

allowed to heat. 

Method 18 Stvrene Analvsis 

Samples were analyzed by GC/FID in the on-site mobile laboratory. The GC/FID instrument 

conditions were as follows: 

Shimadzu GC-14A Gas Chromatograph with 0.5 ml sample loop. 

Column - 30 m long megabore column (0.53 mm I.D) 1 um film thickness, Restek RTX-1 (Equivalent 

toJ&WDB-1) 

Detector - Flame Ionization 

Temperature program - isothermal at 100°C 

Integrator - Shimadzu CR-501. 

To calibrate the GC-FID, the sample loop was flushed with a standard and then injected into the 

GC-FID and the area count was measured by the integrator. This was repeated for each standard. A 

19 

11 
P.29 

calibration curve was developed by performing a least squares fit using the concentrations and 

corresponding area counts of the standards. A calibration curve was developed at the beginning of each 

day of sampling. 

Initially, it was planned to calibrate the GC with styrene standards prepared according to Section 

6.2.2.2 of Method 18 (Liquid Injection Technique). However, at the time of this test, the equipment 

required to generate such styrene standards on site was not available. Therefore, precision of the GCFID was established by repetitive sampling of styrene standards contained in commercially available 

compressed gas cylinders. Immediately before this test, two bottles each of low and mid-range styrene 

calibration standards (nominal 5 and 50 ppmv of styrene in nitrogen) were ordered from Matheson Gas 

Products. When received, the styrene concentrations were certified by vendor analysis to be 3 ppmv (for 

both bottles of nominal 5 ppmv styrene gas) and 52 and 54 ppmv (for the two bottles of nominal 50 ppmv 

styrene calibration gas). For a high styrene calibration standard, an unused bottle of nominal 200 ppmv 

styrene calibration gas (in nitrogen) left over from a previous EPA evaluation carried out at the Eljer facility 

in October 1992 was used. The concentration of styrene in this cylinder was certified by Matheson Gas 

Products to be 195 ppmv when it was received in October 1992. 

Time integrated bag samples were analyzed in the same manner by flushing the sample loop, 

injecting the sample, noting the retention time, and measuring the area count. Identification of styrene 

was based on retention time established by the calibration standards. The area count was converted into 

a concentration using the least squares calibration developed with the calibration standards. Each sample 

was analyzed in duplicate. No interferents were anticipated due to the fact that no other chemicals except 

MEKP are used in the manufacturing process. MEKP is used in very small quantities relative to the 

amount of styrene-containing mix sprayed (1.1 to 1.5% by weight) and would not be detected by the 

GC/FID or the THC analyzers. Also, during a previous test conducted at the Eljer facility, GC-FID analysis 

of EPA Method 18 samples obtained using the adsorption tube procedure showed only the presence of 

styrene in the air exhausted from gel-coat, lay-up, and back-up spray booths.8 

20 

Z O 
P.30 

At the time of testing the EPA Project Officer decided against requiring a separate analysis of an 

appropriate styrene audit material. However, after sampling was over, inconsistent styrene concentrations 

from concurrent GC/FID and THC measurements suggested that it would be appropriate to request that 

an audit sample be supplied for analysis. The audit cylinder was analyzed using the Absorption Tube 

Procedure of Method 18 and the results of this analysis was found to be well within ± 10% of the verified 

concentration. Unfortunately, this showed that there was substantial error in the factory analyses of the 

standard gas mixtures of styrene used for field calibration, necessitating an overall correction of the 

results. Subsequently, it was determined from THC analyses using a THC analyzer that had been 

calibrated with the EPA styrene Audit Standard that the calibration gas standards obtained from Matheson 

Gas Products actually contained 2.2. 39.4 (Matheson-certified 54 ppmv), and 170.8 ppmv of styrene, 

respectively (see Appendix A). As is also shown in Appendix A, the Matheson-certified 52 ppmv styrene 

cylinder was determined by EPA Method 18 analysis (adsorption tube procedure) to contain 39.1 ppmv of 

styrene. The manner in which these errors in styrene concentration were detected and the effort that was 

required to correct the data taken in the field are detailed in the Quality Control Evaluation Report in 

Appendix A. 

SAMPLING WITH THC ANALYZERS 

JUM Instruments Model VE-7 total hydrocarbon (THC) analyzers were used to monitor styrene 

emissions from active spray booths during time periods when Method 18 sampling was conducted at 

these spray booths. In addition, the THC analyzers were used to monitor styrene emissions from 

otherwise active spray booths during mid-morning breaks and lunch breaks and to monitor styrene 

emissions from all other points of ventilation air exhaust. 

Four JUM THC analyzers were used for this sampling. Two of the THC analyzers were 

associated with the GC/FID system in the mobile laboratory. The other two THC analyzers were kept in 

the van and were used to corroborate data taken with the THC analyzers in the mobile laboratory. Figure 

3 shows how. these analyzers were configured. As is shown in this figure, two long sampling hoses were 

21 

2 -\ 
P.31 

used to convey a sample of exhaust air from a process vent to one pair of THC analyzers. These 0.635 

cm (0.25 in.) outside diameter sample lines were made of Teflon and were heated to approximately 66°C 

(150°F) and were 22.9 m (75 ft) long. At the flow rates used for sampling, transit time through the lines 

averaged between 43 and 51 seconds. 

Data from two of the THC analyzers, those in the mobile laboratory, were recorded on a 

dedicated chart recorder and logged on a PC-based data acquisition system (DAS) developed by DEECO, 

Inc.7 Output from each THC analyzer was averaged over a period of one minute and the one minute 

averages were recorded by the data logger. The chart recorder recorded instrumental output on a 

continuous basis. A S-type pitot probe with a K-type thermocouple was positioned in the stack in close 

proximity to the Method 18 sampling probe and the probe used for the THC analyzers. One minute 

averages of the pressure drop across the S-type pitot probe and the temperature recorded by the K-type 

thermocouple attached to the probe were also logged on datalogger. In this manner, if the flow rate of air 

exiting a particular spray booth was observed to change or fluctuate significantly, the run could be 

aborted. Overall, flow rates through a given spray booth exhaust were observed to vary insignificantly 

over time and no runs had to be aborted because of unstable exhaust flow. 

The two THC analyzers in the mobile laboratory were calibrated with 850 ppm ±1 % propane in 

the morning and in the afternoon and instrument zero was verified with hydrocarbon-free air (less than 0.1 

ppm THC). t o be able to develop comparisons with the other two THC analyzers that were calibrated 

with styrene, mid-range styrene calibration gas (nominal 50 ppmv) was also sampled by these instruments 

and the result was recorded. See the Quality Control Evaluation Report in Appendix A for details of this 

comparison. Data from the two THC analyzers in the van were logged on a separate DAS. this PCbased DAS recorded instrumental output once a second and logged the values on a floppy disk along 

with local time. Outputs from these THC analyzers were also recorded on a two-channel chart recorder 

which was annotated and became part of the experimental record. 

The two analyzers in the van were calibrated before sampling started in the morning, and at the 

mid-morning break with mid-range (nominal 50 ppmv) calibration gas and were also checked for linearity 

22 
P.32 

TO HEATED 

SAMPLING LINE 

X TO EPA METHOD 18 

(NIOSH METHOD 1501) 

SAMPLING APPARATUS 

(Used for Other Sampling) 

OUTPUT TO DAS AND 

CHART RECORDER 

EXHAUST 

TO OTHER THC ANALYZER 

SPAN AND ZERO GAS INPUTS 

1 

J.U.M. VE-7 

THC Analyzer 

H& 

t 

<& # 

w^ 

® # 

.ZERO 

AIR 

3* 

ppm 

52* 

ppm 

195' 

ppm 

TO OTHER THC 

ANALYZER 

STYRENE CAUBRATION GAS 

(* Manufacturers analysis, actual values 

were lower. S«e Appendix A) 

Figure 3. Equipment Arrangement Used for Samplhg with THC Analyzers 

23 

2-3 
P.33 

with low (nominal 5 ppmv) and high-range (nominal 200 ppmv) styrene calibration standards. The 

calibration was also checked at the end of the day. As part of each calibration check, instrument zero 

was verified with hydrocarbon-free air (less than 0.1 ppm THC). A 10.7 ppm propane standard was also 

used to determine an instrumental response for propane. 

VOLUMETRIC FLOW RATE DETERMINATION 

For spray booth exhausts, volumetric flow was determined according to EPA Method 2.6 A type 

K thermocouple and S-type pitot probe were used to determine flue gas temperature, and velocity, 

respectively. EPA Method 1 was used to determine the number of traverse points.6 Parameters 

measured included pitot pressure drop, stack temperature, static, and barometric pressure. A computer 

program was used to calculate the average velocity. 

Stack exhaust gas was assumed to be ambient air. Throughout the test relative humidity 

averaged approximately 60% (monitored on-site with a relative humidity sensor, Cole Parmer Model 3310-

40). At typical plant air temperatures (27°C or 80°F) this corresponds to 2% water vapor in the air, the 

value that was used for dry gas corrections. 

The other ventilation exhausts were three or four-bladed exhaust fans. Because of the very 

uneven air flows and the absence of a flow straightening exhaust stack, it was essentially impossible to 

determine the location of suitable traverse points or to make measurements with an s-type pitot probe. 

Thus, with the permission of the EPA Project Officer, a direct reading air velocity meter (Air-Neotronics 

Model 50-4) with a long enough averaging time to suppress the effects of buffeting from the fan exhaust 

was used to determine an average velocity. The direct reading air velocity meter was checked against the 

s-type pitot probe in one of the'spray booth exhaust vents. 

24 
SECTION 4 

RESULTS 

Emission factors were calculated from emission rates determined from THC analyzer and 

Method 18 sampling and knowledge of the amount of styrene used in each stage of manufacture at the 

Eljer facility (from production records for each day of testing, shown in Table 3). Knowledge of the total of 

area sprayed during Method 18 sampling (from inspection of videotapes made of spraying carried out in 

the booth being sampled to identify the type and surface area of mold sprayed) provided the amount of 

styrene expended per square meter of mold sprayed. Comparison of the styrene emission rate 

determined from THC analyzer and Method 18 sampling at the exhaust of a given spray booth with the 

amount of styrene sprayed yielded the emission rate for that part of the manufacturing process. 

Thus, If M, is the mass of styrene sprayed per square foot of mold area for a given phase of the 

spraying operation (supplied from plant production records and analysis of samples of mix from each 

spraying operation) and A, is the surface area of the ith mold sprayed, the mass of styrene sprayed during 

the spraying of that mold, M„ is equal to the product of M, and AJ: 

M, - M, • A, (1) 

If during a period of time, Ts, when THC analyzer or Method 18 sampling was conducted, n molds were 

sprayed, the total mass of styrene sprayed, MT was: 

MT = Ms £ A, (2) 

i-i 

25 

-z-^ 
P.35 

Now, if CSB is the concentration of styrene measured at the exhaust stack of the active spray 

booth under test (from the THC analyzer or Method 18 measurement), and if the average air flow rate 

through the booth under test is QSB. then the rate at which gaseous styrene is emitted through the spray 

booth exhaust vent (emission rate over the time of the Method 18 measurement) is: 

ESB - Css ' Q SB (3) 

and the total mass of styrene emitted during the time Ts is: 

M SB " ESB ' T S (4) 

It should be noted that this calculation presumes that none of the styrene sprayed in a given 

spray booth escaped through the front of the booth into the plant. There are two reasons why this 

assumption is warranted: First, all spraying is directed into the booth, i.e. in reviewing the videotape 

record made to identify which molds were sprayed while sampling was carried out in a particular booth, 

the operator of the spray gun was never observed to direct the spray gun toward the mouth of the booth. 

Second, the net air velocity into the booth (across the mouth of the booth) ranged from 0.47 to 0.57 m/s, 

which should be great enough to capture all styrene vapor generated in the booth. 

Indeed, because styrene emissions associated with spraying do not escape from spray booths 

into the plant, some styrene emissions from other parts of the manufacturing process must be captured by 

air being swept into the spray booths. At the Eljer facility (and perhaps at other similar facilities), molds 

that have been sprayed are frequently left near the mouths of spray booths where spraying is in progress. 

Thus, styrene evolved from a curing mold can be captured by an nearby spray booth. While this is 

probably not a common occurrence for gel coat booths at the Eljer facility (because of limited space in 

front of these booths), it is an integral part of the manufacturing process for the latter two stages of 

spraying. In fact, at any one time, it is common for as many fifteen molds to be in various stages of 

manufacture in the general vicinity of the lay-up and back-up booths. Also, molds are generally left in a 

26 

7As 
P.36 

lay-up booth between sprayings where the surface of the mold is rolled flat. In AP-42 it is noted that 

styrene emissions are increased by such manual rolling.' 

Thus, the concentration of styrene measured at the exhaust of a given active spray booth, CSB, is 

actually the sum of the concentration of styrene vapor emitted in the spray booth, Cs, and the 

concentration of styrene vapor swept into the spray booth from the area adjacent to the spray booth, CP: 

CSB - Cs * CP (5) 

and equation (3) should be written as: 

Ess = (ps

 + CP) • Qse (6) 

Then the emission factor, Fse, for the spray booth under test is the ratio of the amount of styrene 

emitted, MSB. from equation (4) to the amount of styrene sprayed, MT, from equation (2): 

FsB

 1vi7

 (7) 

Styrene emissions not captured by the active spray booth exhaust fans (styrene evolved from 

recently sprayed molds and from open resin mixing tanks) were determined in a similar manner. During 

periods of normal production styrene emissions were measured at every point where plant ventilation air 

was exhausted to the atmosphere (this included four ventilation exhaust fans and four spray booths that 

were not in use but whose exhaust fans v/ere kept running throughout the day). Also, during the two daily 

breaks in production (morning break and lunch break), styrene emissions were measured at normally 

active spray booths where the exhaust fans were left running. Thus, for a given ventilation exhaust fan, 

unused spray booth, or inactive spray booth, if Cvi is the concentration of styrene measured at the exhaust 

point under test (from the THC analyzer), and if the average air flow rate for this location is QVi, then the 

rate at which gaseous styrene is emitted through a ventilation fan, an unused spray booth exhaust vent, 

or an inactive spray booth exhaust vent (mass emission rate over the time of the THC measurement) is: 

27 

IF 
P.37 

EVi = CVi • QVi (8) 

Because these emissions are not directly tied to a mold surface area or stage of the production 

process, mass emissions per unit time were determined by equation (8), and extrapolated to a typical day of 

production using the amount of time spent spraying and the amount of time spent on break. Thus, if Tp is the 

total time spent spraying during the three periods of mold production and if TB is the total time spent on break 

(morning break plus lunch break) then the total mass of styrene emitted from a given ventilation exhaust fan 

or unused spray booth is: 

MVi = Evj • (Tp • TB) (9) 

and the total mass of styrene emitted from an inactive spray booth (during a break in production) is: 

M

ISBj

 = EVj * T B (10) 

Thus, the emission factor, Fv, associated with styrene emissions not captured by the spray booth 

exhaust fans (from recently sprayed molds and from open resin mixing tanks) is the ratio of the total amount 

of styrene vented through the four ventilation exhaust fans and four unused spray booths and the seven 

inactive spray booths to the total amount of styrene sprayed during a given day of production, MST: 

' 8 7 

Z

 MVi * £ MISBj 

F

v

 =

 ~ kT*

 L <1 1> 

M S T 

The amount of styrene sprayed on a given day, MST, was calculated from plant production records 

and chemical analysis (by chromatography) of samples of each mix sprayed (to determine styrene content). 

Knowledge of MST and the average mold area sprayed per day (from the three spraying operations) makes it 

possible to relate styrene emissions not captured by active spray booth exhaust fans to both the mass of 

styrene that was sprayed as well as total mold area. 

28 
P.38 

The overall results of the sampling to determine styrene emissions are detailed below and the 

results of individual THC and EPA Method 18 runs are shown in Table 4. Styrene emissions per unit area of 

mold sprayed are presented in Table 5. Table 6 shows how styrene emissions were determined for styrene 

emissions not captured by the spray booth exhaust fans. Table 7 summarizes total mold surface area 

sprayed, plant raw material usage, and styrene use for each stage of manufacture for each day of testing. 

Table 8 combines the results shown in Tables 4 through 7 and presents average styrene emissions as a 

function of the area sprayed, the total mass that was sprayed, and the total amount of styrene that was 

sprayed. Finally, Table 9 shows relative styrene emissions for each stage of manufacture, including 

emissions not captured by spray booth exhaust fans. 

As Tables 4 and 5 show, styrene emissions based on measurements with the THC analyzers were 

generally much greater than those determined by Method 18. The two techniques had been expected to 

produce comparable results. Indeed, it was felt that if one technique was to be biased toward a lower 

measurement, it would likely be the THC analyzers, because some styrene could be lost in the long heated 

sampling lines used to convey the ventilation air samples to the analyzers. Note, however, that Method 18 

employs a complex procedure to obtain a time-averaged sample of an aerosol which must be transported to 

a GC-FID for analysis. In contrast, sampling with a THC analyzer is relatively straightforward and immediate. 

Nevertheless, as Table 8 shows (within the uncertainty of the data) that styrene emissions as determined 

from the two methods' data do overlap. It should be emphasized that because of the lack of multiple 

measurements, no uncertainty could be determined for styrene emissions not captured by spray booth 

exhaust fans (based only on THC analyzer data). Therefore, the uncertainties in Table 8 are minimum 

values. The lack of multiple measurements for such emissions is especially unfortunate because styrene 

emissions not captured by active spray booth exhaust fans are one of the largest sources of styrene 

emissions. 

Research conducted subsequent to the above analysis of test results has also shown differences 

between EPA Method 18 measurements of styrene emissions and those using THC analyzers.9,10 However, 

the reason for these differences remains the subject of research. It has been suggested that in the Method 

29 

OH 
P.39 

Table 4. Styrene Concentration and Emission Rate Summary for Eljer Plumbingware (June 1993) 

Sampling 

Location 

Gel Coat #1 

Gel Coat #2 

Gel Coat #3 

Lay-Up #1 

Lay-Up #2 

Lay-Up #3 

Back-Up #1 

Date 

6/15/93 

6/17/93 

6/15/93 

6/17/93 

6/16/93 

6/16/93 

6/17/93 

6/16/93 

6/17/93 

6/16/93 

6/16/93 

6/17/93 

Sampling 

Time Span 

0900-0945 

1030-1115 

1120-1205 

1245-1330 

0900-0945 

1030-1115 

1120-1205 

1245-1330 

0740-0825 

0830-0915 

0920-1005 

0740-0825 

0830-0915 

0920-1005 

1100-1145 

1030-1110 

1125-1205 

1100-1145 

1030-1110 

1125-1205 

1245-1330 

1245-1330 

0825-0910 

0825-0910 

Vent 

Row Rate 

(dscmm) 

374.3 

374.3 

374.3 

374.0 

373.6 

373.6 

373.6 

373.6 

362.2 

362.2 

362.2 

358.8 

358.8 

358.8 

358.8 

427.9 

427.9 

427.9 

404.2 

404.2 

370.1 

370.1 

378.4 

378.4 

—Styrene Concent 

Lab THC 

(ppm) 

45.4 

59.5 

N/A 

8.9 

60.5 

67.3 

N/A 

71.6 

60.9 

35.3 

49.4 

51.4 

49.5 

50.9 

42.0 

51.6 

51.4 

44.0 

29.7 

31.3 

100.7 

105.1 

68.3 

74.3 

Van THC 

(ppm) 

N/A 

N/A 

59.7 

5.9 

N/A 

N/A 

65.2 

63.8 

N/A 

N/A 

51.1 

N/A 

N/A 

N/A 

35.2 

49.0 

47.6 

44.8 

28.6 

30.2 

N/A 

N/A 

N/A 

76.0 

ration— 

Method 18 

(ppm) 

21.5 

33.3 

39.2 

6.3 

24.7 

44.3 

62.3 

36.8 

39.7 

27.3 

41.4 

27.8 

30.5 

35.3 

29.7 

39.5 

33.7 

34.3 

26.0 

37.6 

92.8 

92.3 

454 

40.2 

—Styrene Emission Rate — 

Lab THC 

(kg/hr) 

4.413 

5.788 

N/A 

0.864 

5.869 

6.527 

N/A 

6.945 

5.732 

3.319 

4.647 

4.791 

4.618 

4.743 

3.911. 

5.736 

5.711 

4.892 

3.116 

3.285 

9.680 

10.100 

6.711 

7.305 

Van THC 

(kg/hr) 

N/A 

N/A 

5.806 

0.575 

N/A 

N/A 

6.331 

6.188 

N/A 

N/A 

4.813 

N/A 

N/A 

N/A 

3.282 

5.447 

5.288 

4.979 

3.003 

3.175 

N/A 

N/A 

N/A 

7.472 

Method 18 

(kg/hr) 

2.093 

3.243 

3.810 

0.616 

2.399 

4.298 

6.046 

3.575 

3.735 

2.569 

3.986 

2.590 

2.835 

3.289 

2.772 

4.392 

3.751 

3.811 

2.727 

3.946 

8.925 

8.873 

4.462 

3.949 • 

EMISSIONS FOF 

Exhaust 1 

Exhaust 2 

Exhaust 3 

Resin Mix 

Lay-Up #4 

Lay-Up #5 

Lay-Up #6 

Back-Up #2 

VENTS OR 

6/21/93 

6/21/93 

6/21/93 

6/21/93 

6/21/93 

6/21/93 

6/21/93 

6/21/93 

AVERAGE EMISSIONS PER E 

Gel Coat #1 

Gel Coat #2 

Gel Coat #2 

Back-Up #1 

Lay-Up #1 

6/15/93 

6/15/93 

6/22/93 

6/17/93 

6/16/93 

JOOTHSWHER 

0812-0830 

0840-0913 

0916-0940 

1326-1340 

1154-1229 

1302-1315 

1250-1300 

1316-1324 

I NO STYRENE 

363.5 

163.1 

331.4 

187.9 

396.9 

379.1 

353.5 

367.3 

/VAS SPRAYEC 

8.0 

9.7 

9.6 

7.2 

8.7 

10.2 

13.9 

8.2 

OOTH DURING MORNING AND LUNCH BREAK 

1003-1024 

1003-1024 

1005-1031 

1000-1030 

1207-1224 

374.3 

373.6 

373.6 

370.1 

358.8 

6.9 

9.9 

N/A 

5.2 

7.0 

Average (per booth) = 7.0 

i 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A' 

N/A 

N/A 

N/A 

N/A 

N/A 

Total (All Vents) = 6.295 

3 (NO SPRAYING ACTIVITY) 

N/A 

N/A 

7.5 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

Average (per booth) = 0.66 

0.758 

0.412 

0.823 

0.352 

0.894 

1.005 

1.273 

0.779 

0.674 

0.961 

0.732 

0.498 

0.653 

8 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

N/A 

30 

6C 
Table 5. Styrene Emissions per Unit Area of Mold Sprayed, Eljer Plumbingware (June 1993) 

P.40 

Sampling 

Location 

Gel Coat #1 

Gel Coat #2 

Gel Coat #3 

Lay-Up #1 

Lay-Up #2 

Lay-Up #3 

Back-Up #1 

Date 

6/15/93 

6/17/93 

6/15/93 

6717/93 

6/16/93 

6/16/93 

6/17/93 

6/16/93 

6/17/93 

6/16/93 

6/16/93 

6/17/93 

Sampling 

Time Span 

0900-0945 

1030-1115 

1120-1205 

1245-1330 

0900-0945 

1030-1115 

1120-1205 

1245-1330 

0740-0825 

0830-0915 

0920-1005 

0740-0825 

0830-0915 

0920-1005 

1100-1145 

1030-1110 

1125-1205 

1100-1145 

1030-1110 

1125-1205 

1245-1330 

1245-1330 

0825-0910 

0825-0910 

Sample 

Time 

(min) 

45 

45 

45 

45 

45 

45 

45 

45 

45 

45 

45 

Mold 

Area 

(m1) 

44.50 

43.66 

36.14 

0.00 

38.55 

N/A' 

N/A' 

54.63 

34.19 

22.30 

23.97 

Vent 

Row Rate 

(dscmm) 

374.3 

374.3 

374.3 

374.3 

373.6 

373.6 

373.6 

373.6 

362.2 

362.2 

362.2 

Gel Coat Booth Average = 

Relative Standard Deviation (%) = 

45 

45 

45 

45 

40 

40 

45 

40 

40 

28.43 

30.10 

27.22 

34.19 

22.99 

19.51 

N/A" 

40.13 

28.24 

358.8 

358.8 

358.8 

358.8 

427.9 

427.9 

427.9 

404.2 

404.2 

Lay-Up Booth Average = 

Relative Standard Deviation (%) = 

45 

45 

45 

45 

103.58 

103.5B 

80.27 

80.27 

370.1 

370.1 

378.4 

378.4 

Back-Up Booth Average = 

Relative Standard Deviation (%) = 

—Styrene Emitted— 

THC 

(Q/mJ) 

74.4 

99.4 

120.5 

N/A 

114.2 

N/A 

N/A 

90.2 

125.7 

111.6 

148.0 

110.5 

20.5 

126.4 

115.1 

130.7 

78.9 

162.1 

187.9 

N/A 

50.8 

76.3 

116.0 

39.7 

70.1 

73.1 

62.7 

69.0 

68.7 

6.4 

Method 18 

(q/m2) 

35.3 

55.7 

79.1 

N/A 

46.7 

N/A 

N/A 

49.11 

81.9 

86.4 

121.9 

69.5 

40.6 

68.3 

70.6 

90.6 

60.8T 

127.3 

128.2 

N/A 

45.3 

93.1 

85.5 

35.3 

64.6 

64.3 

41.7 

36.9 

51.9 

28.2 

Video camera failure. 

" Video Camera pointed at wrong booth, no data, 

t Value may be in error due to shift in GC calibration during analysis. 

31 
P.41 

Table 6. Determination of Non-Spray Booth Styrene Emission Rate 

Activity 

All Vents During Spraying' = 

All Vents During Breaks'* = 

Usually Active Spray Booths During Breaks* = 

All Vents, All Day, (THC measurements only) = 

Amount 

37.773 

9.443 

7.012 

54.227 

Unit 

kg/day 

kg/day 

kg/day 

kg/day 

* Active spray booths excluded, (6 h of ventilation/day) x (6.295 kg/h from non-spraying vents). 

" Active spray booths excluded, (1.5 h of breaks/day) x (6.295 kg/h from non-spraying vents). 

* Booths normally used for spraying, (1.5 h of breaks/day) x (0.668 kg/h per booth during 

breaks) x (7 booths). 

Date 

6/15/93 

6/16/93 

6/17/93 

Total 

Table 7. Plant Raw Material and Styrene Usage, June 15-17,1993 

Mass 

Gel Coat 

(•<9) 

488.1 

516.2 

513.0 

1517.3 

> of Material Used' 

Lay Up 

(kq) 

2237.1 

2124.6 

2155.9 

6517.6 

Back Up 

(kg) 

1947.3 

1811.6 

1798.9 

5557.8 

—Amount Sprayed— 

Total" 

(kg) 

4672.4 

4452.4 

4467.9 

13592.7 

Styrene" 

(kg) 

1042.9 

999.5 

1002.5 

3044.9 

—Styrene Emitted— 

THC 

(kg) 

246.0 

244.2 

246.9 

737.1 

Method 18 

(kg) 

188.4 

187.4 

189.2 

565.0 

Date Gel Coat* 

(m2) 

Area Sprayed 

Lay Up 

(m2) 

Back Up 

-Areal Density 

Gel Coat 

(kg/m2) 

Lay Up 

(kg/m2) 

Back Up 

(kg/m2) 

6/15/93 

6/16/93 

6/17/93 

Total 

664.6 

646.0 

653.0 

1963.6 

640.5 

642.0 

652.1 

1934.5 

640.5 

642.0 

652.1 

1934.5 

0.7344 

0.7990 

0.7856 

0.7727 

3.4930 

3.3092 

3.3063 

3.3691 

3.0404 

2.8217 

2.7588 

2.8729 

* Not counting MEKP. See Table 3 for details of raw material use. 

" Gel Coat = 32.2% styrene, Lay-Up Mix = 21.4% styrene, Back-Up Mix = 20.9% styrene. 

* Includes molds rejected due to imperfections. 

32 

ST-
Table 8. Styrene Emissions for Each Part of the Manufacturing Process 

P.42 

(a) Styrene Emissions per Unit Area of Mold Sprayed 

Emissions from: 

Gel Coat Booths 

Lay Up Booths 

Back Up Booths 

Non-Spray Booth Emissions 

All Emissions 

THC Analyzer 

Styrene 

(Q/m°) 

110.5 

116.0 

68.7 

83.7 

378.9 

Pop. Std. 

Dev. 

(Q/mJ) 

21.2 

43.1 

3.8 

N/A 

48.1' 

EPA Method 18 

Styrene 

(0/m2) 

69.5 

85.5 

51.9 

83.7 

290.6 

Pop. Std. 

Dev. 

(q/m!) 

26.4 

28.3 

12.6 

N/A 

40.7' 

(b) Percent of Total Mass Used in Each Stage of Manufacture that was Emitted as Styrene 

Emissions from: 

Gel Coat Booths 

Lay Up Booths 

Back Up Booths 

Non-Spray Booth Emissions 

All Emissions 

THC t 

Styrene 

(%) 

14.3 

3.4 

2.4 

1.2 

5.4 

,nalyzer • 

Rel. Std. Dev. 

(%) 

2.7 

1.3 

1.5 

N/A 

0.7' 

EPA Method 18 

Styrene 

(%) 

9.0 

2.5 

1.8 

1.2 

4.2 

Rel. Std. Dev. 

(%) 

3.4 

0.8 

0.4 

N/A 

0.6' 

(c) Percent of Styrene Used in each Stage of Manufacture that was Emitted 

Emissions from: 

Gel Coat Booths 

Lay Up Booths 

Back Up Booths 

Non-Spray Booth Emissions 

All Emissions 

— TWP t 

Styrene 

(%) 

44.4 

16.1 

11.4 

5.3 

24.2 

Jialyzer 

Rel. Std. Dev. 

(%) 

. 8.5 

6.0 

0.6 

N/A 

3.3' 

Styrene 

(%) 

27.9 

11.9 

8.6 

5.3 

18.6 

Rel. Std. Dev. 

(%) 

10.6 

3.9 

2.1 

N/A 

2.8' 

Minimum estimate. Assumes each process independent with no contribution from the non-spraying emissions 

component. 

33 

S2> 
P.43 

18 procedure, styrene can polymerize before analysis and may also have a very low vapor pressure at 

stack or instrument conditions. Both of these conditions would result in a lower measurement for styrene. 

Although it is not specifically noted in AP-42,1 it is reasonable to assume that styrene emission 

factors cited in this standard for polyester resin plastics products fabrication include emissions not captured 

by active spray booths. Thus, in order to compare the results obtained in this study with those cited in AP42, it is necessary to apportion styrene emissions from non-spray booth emissions to those parts of the 

process associated with spraying operations: gel coating, lay-up and back-up. The following approach was 

followed to apportion non-spray booth emissions to each of the spraying operations. 

1. Obtain an average emission factor for each of the spraying operations by averaging the Method 

18 and THC measurements for each of the three spraying operations (gel coating, lay-up and 

back-up) 

2. Apportion emissions not directly associated with spraying to each of the three spraying 

operations as follows: 

2.1 Assume that vents that are in the close proximity to a particular spraying operation capture 

the emissions (from curing molds) generated by that operation. Some non-spraying 

emissions are surely captured by active spray booths. However, for the purposes of 

apportioning emissions to obtain a comparison with AP-42, we will assume that all 

emissions captured by an active spray booth are emissions directly related to that phase of 

manufacture. 

2.2 Thus, because the area of the plant used for gel coating is more or less off by itself, we 

assume that the three exhaust fans on the side of the plant adjacent to the gel coat spray 

booths capture curing emissions from molds previously sprayed in one of the three gel coat 

booths. Likewise, we will assume that lay-up booths 4, 5, and 6, (that were not used for 

spraying) capture styrene emissions from molds that were sprayed in lay-up booths 1,2, 

34 

34r 
P.44 

and 3, and we will assume that back-up booth 2 (that was not used for spraying) captures 

styrene emissions from molds that were sprayed in back up booth 1. 

2.3 Similarly, we will assume that during breaks in spraying (morning break, lunch) any 

emissions captured by a particular spray booth came from molds that were sprayed in the 

phase of manufacture normally associated with that spray booth. This includes styrene 

emissions captured during the 15 minutes before work commenced, the 30 minute 

midmoming break, the 30 minute lunch break, and the 15 minutes that the vents are 

operated at the end of the day after spraying has ended. 

2.4 Assume that resin mixing room emissions that are exhausted to the atmosphere can be 

apportioned to emissions from the lay-up and back-up operations because these resins are 

only used in those phases of manufacture; gel coat is supplied in pre-mixed 55 gallon 

drums. We will apportion the resin mixing room emissions according to the mass of mix 

sprayed in each of the two operations. 

' Using these assumptions, the following emission factors were calculated: 

Gel Coat 47.5% of the styrene sprayed in that phase of manufacture 

Lay-Up 20.0% of the styrene sprayed in that phase of manufacture 

Back-Up 12.1% of the styrene sprayed in that phase of manufacture 

These data suggest that spray booth emissions are higher than those cited in AP-42 for gel coating 

and spray lay-up (see Table 1, reproduced from AP-42, for styrene emission factors).1 AP-42 cites a value 

of from 26 to 35% of styrene monomer being emitted for gel coat that contains no vapor suppressing 

additives (as was the case at Eljer). The results calculated according to the above procedure to apportion 

non-spraying emissions to each part of the manufacturing process that incorporates spraying suggest that 

nearly 48% of the styrene in the gel coat mix is lost to the atmosphere. 

35 

65-
P.45 

AP-42 makes no distinction between styrene emissions from lay-up booths or from back-up booths, 

and indicates that, with vapor suppressing additives in the mix, from 3 to 9% of the styrene sprayed in this 

operation is emitted. If vapor-suppressing additives are not added to the mix, emissions rise to from 9 to 

13% of the styrene sprayed. At Eljer, vapor suppressants are added to the lay-up and back-up mix. 

However, the levels of styrene emissions measured there suggest that the emissions levels are probably 

higher than what AP-42 cites as typical for non-vapor suppressed emissions, particularly for the lay-up phase 

of manufacture. Thus, results calculated according to the above apportioning procedure show that styrene 

emissions to the atmosphere averaged 20% of the styrene sprayed in the lay-up booths and 12% of the 

styrene sprayed in the single back-up booth. 

These generally higher than expected emission levels may be, at least in part, due to the nature of 

the process. At the Eljer facility (which is probably like other such manufacturing plants), molds that have 

been sprayed are frequently left near the mouths of spray booths where spraying is in progress. Hence, 

styrene evolved from a curing mold can be captured by an adjacent spray booth. While this practice is not 

common in the gel coat booths (because of limited space in front of the booths at the Eljer facility),; this 

practice is an integral part of the manufacturing process for the latter two stages of spraying. In fact, at any 

one time, it is common for as many fifteen molds to be in various stages of manufacture in the general 

vicinity of the lay-up and back-up booths. Also, molds are generally left in a lay-up booth between sprayings 

where the surface of the mold is rolled flat. In AP-42 it is noted that styrene emissions are increased by such 

manual rolling.1 

Finally, AP-42 provides no separate estimate of styrene emissions not captured by spray booths. 

While such emissions are certainly a function of ventilation system design and the specific equipment at a 

given facility, at Eljer it was found that 6% of all the styrene sprayed exits the facility through openings other 

than spray booth exhausts. As noted in Table 9, this corresponds to rrom 22 to 29% (depending on the 

measurement method) of all styrene emitted to the atmosphere; thus, styrene emissions not captured by 

spray booths represent a source of styrene emissions as great as (or possibly greater than) styrene 

emissions associated with any one of the spraying operations. 

36 

3G 
Table 9. Distribution of Styrene Emissions from Each Part of the Manufacturing 

Process, Including Styrene Emissions not Captured by Spray Booths 

P.46 

Date 

6/15/93 

6/16/93 

6/17/93 

Average 

F 

Gel 

Coat 

Booths 

(%) 

29.9 

29.2 

29.2 

29.4 

rom THC 

Lay 

Up 

Booths 

(%) 

30.2 

30.5 

30.6 

30.5 

Analyzer Measurements 

Back Up 

Booths 

(%) 

17.9 

18.1 

18.2 

18.0 

NonSpraying 

(%) 

22.0. 

22.2 

22.0 

22.1 

All 

Source 

s 

(%) 

100.0 

. 100.0 

100.0 

100.0 

Gel Coat 

Booths 

(%) 

24.5 

24.0 

24.0 

24.2 

From Method 18 Measurements 

Lay 

Up 

Booth 

s 

(%) 

29.1 

29.3 

29.5 

29.3 

Back Up 

Booths 

(%) 

17.6 

17.8 

17.9 

17.7 

NonSpraying 

(%) 

28.8 

28.9 

26.6 

28.8 

All 

Source 

s 

(%) 

100.0 

100.0 

100.0 

100.0 

RECOMMENDATIONS FOR FUTURE SAMPLING 

Three methods are available to measure hydrocarbon emission rates for an emission source such 

as Eljer Plumbingware. Two of the three methods were used here: EPA Method 18 (using Tedlar bags to 

obtain time-averaged samples) and THC analyzers (direct sampling through heated hoses). The third 

method that is appropriate is a variation of Method 18 that uses a charcoal-filled adsorption tube instead of a 

Tedlar bag to obtain a time integrated aerosol sample. With this method, styrene (or another VOC) that was 

adsorbed on the activated charcoal during sampling is desorbed in a known volume of carbon disulfide 

(usually in the laboratory). Then, a known volume of the carbon disulfide and desorbed hydrocarbon mixture 

is injected directly into a GC, usually equipped with an FID. 

The advantage of the first two methods is that results are obtained on site and while the Method 18 

procedure using Tedlar bags is complex, it has been used successfully for some time and is well 

documented.5 THC analyzers have also been used for a number of years and usually employ an FID for 

detection. With these devices, time averaging is accomplished by averaging recorded instrument response 

over the period of interest. Important caveats for THC analysis are that first, if more than one hydrocarbon is 

37 

5^r 
P.47 

present, some way must be found to determine the relative concentration of each component (presuming the 

split remains constant throughout the sampling period) and second, the instrument should be calibrated with 

the compound that is being measured (at a concentration near that which is expected, if possible). An on 

site GC-FID could be used for speciation (from direct sampling) or samples obtained with adsorption tubes 

(taken concurrently with other measurements) could be used to provide compound speciation. 

The problems encountered in this investigation were exacerbated by inaccurate styrene 

concentration determinations on the part of Matheson Gas Products for the calibration gas standards. 

However, the general disagreement between the THC analyzers and the EPA Method 18 Tedlar bag results 

cannot be due to inaccurate calibration gases because both instruments were calibrated with the same 

calibration gas standards. Thus, though absolute response in the field was in error, this problem was 

eliminated when the data were corrected according to the procedures documented in Appendix A. This 

disagreement does suggest that it would have been desirable to use. a third method to ascertain which of the 

two other methods were in error. Some EPA Method 18 adsorption tubes should have been run during the 

test (concurrent with other sampling) to provide a third, separate determination of styrene concentration. In 

the future, such a procedure should be followed. Thus, in a future emissions test, two techniques (perhaps 

Method 18 with Tedlar bags and THC analyzers) should be used to measure hydrocarbon concentration 

and, at a minimum, some Method 18 adsorption tubes should be taken concurrently with other samples. In 

the case of a disagreement, results from the analysis of the adsorption tubes could be used to determine 

which technique provides the best results. In the case where time is available, Method 18 samples with 

adsorption tubes could be taken on the first day of sampling and be analyzed immediately so that the results 

from the adsorption tube analysis could be compared with results from the other two methods. 

Two final recommendations are in order. First, all calibration standards should be independently 

checked before a field evaluation commences. Second, it is also recommended that prior to any emissions 

testing, an EPA audit standard should be obtained and evaluated to validate laboratory standard operating 

procedures. 

38 

2 $ 
P.48 

SECTION 5 

REFERENCES 

1. Office of Air Quality Planning and Standards, Compilation of Air Pollution Emission Factors, Volume 1 : 

Stationary and Point Sources, AP-42, Fourth Edition (GPO 055-000-00251-7). U.S.Environmental 

Protection Agency, Research Triangle Park. NC. September 1985 [supplemented October 1986 GPO 

055-000-00265-7) and September 1988 (GPO-055-000-00278-9)], Section 4.12, Polyester Resin 

Plastics Fabrication, Table 4.12-1. 

2. Rogozen, M. B., Control Techniques for Organic Gas Emissions from Fiber glass Impregnation and 

Fabrication Processes, ARB/R-82/165, California Air Resources Board, Sacramento, CA, (NTIS 

PB82-251109), June 1982. 

3. Modern Plastics Encyclopedia, 1986-1987,63(1 OA), McGraw-Hill, Inc., New York, NY, October 1986. 

4. LaFlam, G. A., Emission Factor Documentation for AP-42 Section 4.12: Polyester Resin Plastics 

Product Fabrication, Pacific Environmental Services, Inc., Durham, NC, November 1987. 

5. Von Lehmden, D.J., DeWees, W.G., and Nelson, C, Quality Assurance Handbook for Air Pollution 

Measurement Systems: Volume III. Stationary Sources Specific Methods, Section 3.16. U.S. 

Environmental Protection Agency, Research Triangle Park, NC. EPA/600/4-77/027b, NTIS PB80-

112303, May 1979. 

6. Code of Federal Regulations 40 (Parts 53 to 60), Revised as of July 1,1991, Office of the Federal 

Register, National Archives and Records Administration, U. S. Government Printing Office, 

Washington. DC 20402. 

7. Steinsberger, S.C. Buynitzky. W.D., DeWees, W.G., Knoll, J.E., Midgett, M. R., Hartman, M., U.S. EPA 

Evaluation of the Hazardous Organic Mass Emission Rate (HOMER) System for Measurement of 

Hazardous Organic NESHAPS Emissions. Presented at the 86th Annual Meeting of the Air and Waste 

Management Association, Denver. CO, June 13-18,1993. 

8. Felix, L., Merritt, R., Williamson, A.. Evaluation of the Polyad® FB Air Purification and Solvent Recovery 

Process for Styrene Removal, U. S. Environmental Protection Agency, Research Triangle Park, NC. 

EPA-600/R-93-212, NTIS PB94-130317, November 1993. 

9. Personal Communication from Bahner, M.A., Research Triangle Institute, Research Triangle Park. NC, 

to J.W. Jones, U.S. Environmental Protection Agency, Research Triangle Park, NC, April, 1996. 

10. Schweitzer, J., Pultrusion Industry Council Phase II Emission Study Report, Society of the Plastics 

Industry (SPI) Composites Institute, New York. NY, February, 1996. 

39 
P.49 

APPENDIX A 

QUALITY CONTROL EVALUATION REPORT 

SUMMARY 

A Quality Assurance Project Plan (QAPP) was written and approved for this project. No field audits 

were planned or performed. However, as stated in the QAPP, vendor-certified calibration gases (3. 52,54, 

and 195 ppmv of styrene in nitrogen and zero air with less than 0.1 ppm THC content) served as field 

performance audit samples for EPA Method 18 and THC sampling. Unfortunately, as documented below, 

the concentrations of the styrene calibration gases were incorrectly determined by the vendor, Matheson 

Gas Products. Actual concentrations were determined to be 2.2,39.1, 39.4, and 170.8 ppmv of styrene, 

respectively. EPA personnel were on site to oversee diagnostic measurements. In the field, QC was 

addressed by adherence to standard sampling protocols either as specified for EPA Method 18 or by 

following a standard operating procedure (modified as needed for this particular sampling task) with the THC 

analyzers as specified in the THC instruction manual. 

In the Southern Research Analytical Chemistry facilities, QC is addressed by strict adherence to 

standard operating procedures (SOP) previously defined and implemented. While random audits can occur 

while the field samples from any project are being analyzed, and audits are regularly performed by the QA 

officer at this facility, no audit was planned or performed as part of this project. 

Overall, the data quality indicator (DQI) goals were not achieved. This is partially due to reduced 

plant availability because the work week at the plant was one day less than was expected when the project 

was initiated. Mainly, the DQI goals were not achieved because significant problems were encountered with 

40 

-fD 
P.50 

the calibration gases purchased for this test. These difficulties are discussed in detail in the following section 

on QA/QC problems. 

With respect to plant availability, we were able to perform Method 18 sampling for only three of the 

four days that were originally planned. Unfortunately, because the following week was scheduled for a 

second phase of this Work Assignment, the testing of a liquid chemical scrubber, only a minimal extension of 

this testing could be accommodated. Within these constraints the Project Officer concluded that in order to 

obtain the needed data within the time available Method 18 sampling would focus on the operational spray 

booths (a total of seven) while styrene emissions not captured by active spray booths (spray booths used as 

ventilation air exhausts and separate ventilation air fan exhausts) would be measured with the THC 

analyzers. Thus, from June 15 through 17, Method 18 testing was conducted at the spray booth exits and 

the THC analyzers were used as continuous monitors to measure styrene emissions at the same locations 

and times used for Method 18 sampling. On Monday, June 21, while preparations were underway to begin 

Phase 2 of this Work Assignment, the THC analyzers were used to quantify styrene emissions not captured 

by active spray booths that had not been determined during the previous week of testing. 

SIGNIFICANT QA/QC PROBLEMS 

One significant QA/QC problem was encountered. After sampling for both phases of the Work 

Assignment had been completed, samples of the nominal 3 and 52 ppmv styrene cylinder gas standards 

taken in the field on June 24 with Method 18 (Section 7.4. Absorption Tube Procedure, equivalent to NIOSH 

Method 1501) were analyzed to verify sample recovery for the second phase of this Work Assignment. 

These samples were analyzed on July 7. Styrene concentrations of 2.3 and 35.8 ppmv were determined 

corresponding to vendor-certified values of 3 and 52 ppmv. Such large discrepancies between the styrene 

concentrations certified by Matheson Gas Products and the styrene concentrations measured with the 

adsorption tubes suggested that the vendor-certified concentrations of these calibration gases were in error 

or that some part of the laboratory analysis performed by Southern was incorrect. Therefore, a two-pronged 

41 

M 
P.51 

investigation followed that focused on the possibility that the styrene calibration gases were in error, that 

Southern made incorrect determinations of the styrene content in the calibration gases, or a combination of 

the two possibilities occurred. 

With respect to the calibration gases, two bottles each of the low styrene concentration (nominal 5 

ppmv styrene in nitrogen) and intermediate styrene concentration (nominal 50 ppmv styrene in nitrogen) 

calibration gases were ordered from Matheson Gas Products for this test on May 13,1993 and were 

received in early June. As indicated above, Matheson Gas Products certified that the styrene content in the 

two bottles of low concentration gas were actually 3 ppmv while the styrene concentration in one of the 

intermediate calibration standards was 52 ppmv and the other intermediate concentration standard was 54 

ppmv. Two cylinders of the high calibration standard (nominal 200 ppmv styrene in nitrogen) were ordered 

on September 30,1992 for an earlier EPA-sponsored test at the Eljer facility. These gases were received in 

mid-October, 1992. One cylinder of this gas was not used during that test and was taken on this test for use 

as a high styrene concentration calibration gas. Matheson certified that the styrene content was 195 ppmv 

for this cylinder. Matheson Gas Products was contacted and a representative indicated that as far as their 

records indicated, the cylinders were properly prepared and passivated and that stable styrene 

concentrations were determined in their laboratory (and were recorded on the calibration tags supplied with 

each cylinder) when the gases were shipped to Southern. 

With respect to Southern's laboratory procedures, while conversations were being held with 

Matheson Gas Products, two other samples of the 3 and 52 ppmv styrene calibration gases were taken on 

July 13 and analyzed to check the procedures followed during the earlier analyses. In addition, different 

high-purity liquid laboratory standards for styrene (from two different suppliers, Aldrich and Chem Service) 

were used to prepare independent calibration standards that were checked against one another on the same 

GC FID used for both sets of analyses. Approximately six calibration standards (of different concentrations 

below, centered about, and above those measured from the earlier analyses of the adsorption tubes) were 

prepared by adding a known quantity of each high-purity liquid styrene standard to a known quantity of highpurity carbon disulfide. Known microliter volumes of these liquid mixtures were then injected into the GC-FID 

42 

42-
P.52 

used for the adsorption tube analyses and the peak areas were recorded and averaged. No statistically 

different result was determined for the two liquid styrene standards and the analyses of these two adsorption 

tube samples were consistent with the earlier results. To make a definitive assessment of the actual styrene 

content of the Matheson-certified 3 and 52 ppmv styrene calibration gases, on July 29 and 30. four 

adsorption tube samples each were taken from each calibration gas cylinder (using Method 18, the 

adsorption tube procedure). Two adsorption tube samples of each styrene calibration standard were taken 

inside (at an average laboratory temperature of 22°C) and two adsorption tube samples were taken outside 

with the calibration gas bottles in the direct sun (an an average temperature of 38°C). The reason samples 

were taken at laboratory conditions and at conditions that mimicked ambient field temperatures experienced 

at the Eljer facility was to determine if styrene gas was condensed within the sampling apparatus at room 

temperature - a possible explanation for the apparent low recovery based on Matheson's certified values. 

The adsorption tubes (from the same lot used at Eljer SKC, Inc. catalog # 226-01, coconut charcoal. Lot 

120) were analyzed by removing the charcoal from the tubes and desorbing the styrene into high-purity 

carbon disulfide. As part of the analytical procedure, the desorption efficiency of styrene from this lot of 

coconut charcoal is separately determined each time a sample or set of samples is analyzed. The 

desorption efficiency was determined to be 90.25%, equal to the value that has been determined in the past. 

The results of these analyses, carried out during the first week of August, was that no difference could be 

detected between samples obtained inside or outside the laboratory and that the Matheson-certified 3 ppmv 

styrene gas was 2.69 ppmv with an RSD of 3.55% while the Matheson-certified 52 ppmv styrene gas was 

39.1 ppmv with an RSD of 0.55%. No error was found in the analytical procedures followed in these 

analyses, in the preparation of the two sets of calibration standards, or in the behavior or operation of the 

GC-FID used for these analyses. 

Next, a performance evaluation audit standard was requested from EPA to determine with certainty 

if the error was due to our analytical procedures. The cylinder was sent to Southern on September 17 and 

the results of Southern's triplicate analysis (using the Method 18, Adsorption Tube Procedure) of the styrene 

content in the cylinder was reported to the EPA on September 21. After it was determined that Southern's 

43 

* & 
P.53 

analysis was within 96.6% of the actual styrene concentration of 58.6 ppmv (with an accuracy of ± 2.2%), it 

was concluded that the concentrations reported on Matheson's analysis of all the gas samples provided for 

this test were in error. The results of the tests of the EPA performance evaluation audit sample are shown in 

Table A-1. Table A-2 shows the results of tests performed to determine the actual styrene content of these 

gases. No other corrective actions were required or taken during the collection of samples and data or 

during subsequent analysis of samples collected during testing. 

The values reported in Table A-2 were obtained by two separate methods. First, as part of the 

investigation discussed above, EPA Method 18, Adsorption Tube Procedure (equivalent to NIOSH Method 

1501), was used to make triplicate determinations of the styrene content of each of the nominal 3, 52, 54, 

and 195 ppm styrene calibration gases. All of these determinations were completed by September 14. 

Second, on September 29. a JUM VE-7 THC analyzer (one of the THC analyzers used in the sampling van) 

was allowed to stabilize for 24 hours on filtered ambient laboratory air and was then spanned with 10.7 ppm 

± 1% propane (unfortunately, other propane standards were not available when these measurements were 

performed) and zeroed with a THC-free zero air standard (s 0.1 ppm of hydrocarbon compounds). The THC 

analyzer was then used to sample the 58.6 ppm EPA audit standard, as well as the nominal 3, 54, and 195 

ppm styrene calibration gases (at this time the cylinder containing the 52 ppm calibration gas had been 

exhausted). Styrene content was determined based on the response of each of the calibration gases to the 

value measured for the EPA audit standard. Zero and span checks performed at the beginning, middle and 

at the end of the THC measurements confirmed instrumental stability. 

These results required that, at best, all of the data be scaled to reflect the true concentrations of 

styrene present in the gas cylinders obtained from Matheson Gas Products that were used for field 

calibrations. At worst, the data could be completely compromised because the styrene within the cylinders 

supplied by Matheson could have been slowly polymerizing since the cylinders were prepared and the 

styrene concentrations measured after the test wouid not represent styrene concentrations 

44 

A ^ 
P.54 

Table A-1. Results of Analyses of EPA Performance Evaluation Audit Sample* 

Sample" 

1. 

2. 

3. 

Average ± RSD 

Measured (ppm) 

55.6 

57.0 

57.1 

56.6 ±1.5% 

Actual (ppm) 

58.6 

58.6 

58.6 

58.6 ± 2.2% 

Rel % Difference 

-5.1 

-2.7 

-2.6 

-3.4 

* Cylinder CLM 008308. Specified as containing styrene at a concentration under 100 

ppm with the balance gas being nitrogen. Content later quoted by EPA to be 58.6 ppm 

± 2.2% RSD. 

" Analysis by EPA Method 18, Absorption Tube Procedure, with GC/FID. Aside from the 

diluent (CS2), styrene was the only material detected. 

Table A-2. Results of Analyses of Matheson Calibration Gas 

Matheson Analysis* 

(ppm) 

3 

52 

54 

195 

Method 18 Analysis" 

(ppm) 

2.69 

39.1 

37.8 

176.8 

RSD (%) 

3.55 

0.55 

2.07 

4.06 

THC Analysis' 

(ppm) 

2.16 

N/An 

39.45 

170.8 

RSD (%) 

0.25 

-

0.12 

0.18 

Comparability 

(% Diff.) 

21.9 

— 

-4.3 

3.5 

* As indicated on gas cylinder, ppm styrene in nitrogen. 

" Absorption Tube Procedure using charcoal tubes. 

f

 THC calibrated with 10.7 ppm propane in nitrogen. Response referred to styrene by analysis 

of EPA performance evaluation audit sample (58.6 ppm styrene measured 151.06 ± 0.24 

ppm with propane-based calibration). 

n

 Cylinder exhausted before THC measurements could be made. 

present in the cylinders at the time of the test. The latter eventuality was explored with Matheson in the initial 

conversations that were directed toward determining the source of the disagreement. As indicated above, 

Matheson Gas Products asserted that the cylinders were properly prepared and passivated. While 

Matheson was unable to explain why the concentrations were so far from those determined by their original 

in-house analysis, they did maintain that if the temperature indicating strips on the sides of the cylinders had 

45 

4 ^ 
P.55 

not changed color (indicating exposure to temperatures that could degrade the sample), styrene 

concentrations within the cylinders should have remained stable through the time period of the test and our 

subsequent determination of the actual styrene concentrations within the cylinders. Because none of the 

temperature indicating strips on the sides of the cylinders had changed color (indicating the temperature of 

the cylinder had reached or exceeded 125°F), we proceeded to correct the data assuming that styrene 

concentrations in the calibration cylinders measured after the test were representative of styrene 

concentrations present during testing. 

Both THC data and EPA Method 18 data required correction. Correction of the THC data was 

relatively straightforward. Lab THC data was taken on THC analyzers calibrated with propane (850 ppm, ± 

1%). During the test, the nominal 54 ppm styrene calibration gas (actually 39.45 ppm by later THC analysis) 

was observed to produce an equivalent propane response of 115 ppm on THC#1 and 116 ppm on THC #2. 

Thus, these data were scaled by the ratio of 0.3430 (or 39.45/115) for THC #1 and 0.3401 (or 39.45/116) for 

THC #2. Both THC analyzers in the sampling van were calibrated with the same nominal 52 ppm styrene 

calibration gas (actually 39.1 ppm by Method 18 analysis). Because this cylinder was emptied before the 

THC measurements reported in Table A-2 could be made, results obtained with these analyzers were scaled 

by a ratio of 0.7519 (or 39.1/52). 

The EPA Method 18 data required more extensive correction. The concentration of a VOC as 

measured by a gas chromatograph is determined by first measuring the instrumental response (peak area) 

to a set of calibration gases and then relating the peak area measured for each calibration gas to the known 

concentration of that gas. Because a FID produces a linear response to concentration, a linear fit is usually 

made to the peak area (x) versus concentration calibration (y) data. 

In the field, after measuring the peak area response to each calibration gas (nominal 3, 54, and 195 

ppm styrene), linear fits were made to relate peak area to styrene content for subsequent determinations. 

Thus, to correct the GC data obtained on this test, each linear (calibration) fit obtained in the field was 

recalculated based on what the actual styrene concentration of each calibration gas was later determined to 

be and the styrene concentrations obtained during the time that calibration was used were corrected with the 

new linear fits. For these corrections, the THC analyzer-determined values for the calibration gases were 

46 

4-U 
P.56 

used because during those measurements repeated, direct comparisons were made with the EPA audit 

standard. Table A-3 presents the calibration data determined for each day of testing (on site). 

Table A-3. GC-FID Calibrations Performed at Eljer Plumbingware* 

Nominal Styrene 

Concentration 

(ppm) 

3 

54 

195 

Actual Styrene 

Concentration 

(ppm) 

2.16 

39.45 

170.8 

GC-FID 

Peak Area 

6/15/93 

(0935-1151) 

4994 

118910 

343248 

GC-FID 

Peak Area 

6/16/93 

(0819-0902) 

3903 

100744 

364290 

GC-FID 

Peak Area 

6/17/93 

(1052-1145) 

6986 

273351" 

968576 

GC-FID 

Peak Area 

6/21/93 

(before 0800) 

9428 

201447 

780310 

Performed by DEECO. Inc.. 

Reanalysis at 1346 gave peak area of 176150 

During the test, full instrumental calibrations were performed early each morning and afterwards, 

occasional checks were performed with the nominal 54 ppm calibration standard to assure that instrument 

response had not drifted. Because of the limited time available for sampling (due to the plant operating 

schedule) only one full calibration was performed each day. 

These corrections are not completely satisfactory. In particular, the peak area measured for the 

195 ppm styrene calibration gas (actually 170.8 ppm by subsequent THC analysis), appears to be low as 

compared to the other two calibration gases. It could be that this relatively high concentration of styrene did 

change between the time the test was performed and the time that the concentration of this calibration gas 

was measured in the laboratory. Another likely possibility is that the Teflon sampling line that was used to 

convey this gas to the GC was not kept warm enough (the lab trailer was air conditioned and maintained at 

approximately 75°F) and some of the styrene condensed in the line before it could reach the inlet of the GC. 

Before the test this concentration of styrene had been observed to condense in Teflon sampling lines under 

similar laboratory conditions. Because of this discrepancy, and because few of the styrene concentrations 

measured were greater than 100 ppm (corrected), it was decided to eliminate the 195 ppm (actual 170.8 

ppm) point from the set of calibration data from which new fits were determined to correct the original data. 

47 

4r> 
P.57 

One other significant problem was encountered in correcting the GC data. On June 17, at the 

morning calibration, GC response to styrene was observed to have increased dramatically as compared to 

the response measured during earlier calibrations. Afterwards, instrumental response was monitored closely 

while two samples (one from a Tedlar bag and another from a Teflon bag) were repeatedly analyzed. 

Approximately one hour after that calibration, the GC was observed to have stabilized at a lower response 

level and a single point calibration was performed with the 54 ppm (39.45 ppm actual) so that samples that 

had been accumulating could be analyzed. Thus, we were forced to rely on a single point calibration for 

Method 18 data acquired on June 17. 

DATA QUALITY 

The following procedures were used to determine how well data DQI goals were met: 

• Precision is expressed as percent coefficient of variation: 

%CV=100x(S>/Xavg) 

where S, is the standard deviation of x number of data values from the data set and Xavg is the mean or 

average of the x number of data values from the data set. 

48 

*<& 
P,58_ 

• Bias is expressed as a difference or percent difference between measured and known values: 

Bias = (X-T) 

%RPD = 100 [(X-T)/T] 

where T is the true value (reference standard) and X is the mean sample concentration. %RPD is the 

relative percent difference. 

• Completeness is expressed as a percent between successful analyses and total attempts: 

Completeness = 100 S/A . 

where S is the number of successful analyses and A is the total number of attempts. 

• Comparability is expressed as a percent difference (%Diff) between the results for two methods: 

%Diff = 100 (R,-R2.V[(rVR2)/2] 

where R, is the result for one method and R2 is the result for the second method. 

Table A-4 shows the DQI goals that were estimated for critical measurements in the QAPP, and 

Table A-5 presents the DQI values for measurements carried out with EPA Reference Method 18 and the 

THC analyzers in the sampling van and the mobile lab. Below, the precision, accuracy, and completeness of 

the data that were obtained in this project are reviewed. 

49 

4^ 
P.59 

Precision 

Precision, as reported in Table A-5 (a), meets the DQI goals shown in Table A*4 for Method 18 with 

the exception of the 170.8 ppm calibration point which was expected. Mainly, this is because field 

calibrations were compromised by incorrect concentrations for the calibration gases. Using the procedure 

described above, the values reported in Table A-4 (a) were obtained by generating new fits to the original 

calibration data (excluding the 170.8 ppm point), as taken for each day of testing and then determining the 

difference between the correct styrene concentration (from THC remeasurement) and styrene 

concentrations determined from best linear fit to the calibration data. 

Table A-4. Data Quality Indicator Goals for Critical Measurements Estimated in QAPP 

Method and 

Reference 

EPA 

Method 18, 

Section 7.1 

and 

Section 7.3 

Total 

Hydrocarbon 

Analyzer with 

FIDT. 

Measurement 

Parameter 

VOC 

Speciation and 

Concentration 

Hydrocarbon 

compounds 

in air. 

Experimental 

Condition 

1. Spray booth. 

Vent and air 

exhausts. 

2. Headspace 

measurements 

from styrene 

storaqe tanks.TM 

1. Spray booth 

Vent and air 

exhausts. 

2. Headspace 

measurements 

from styrene 

storaqe tanks." 

Expected 

Precision 

(RSD,%) 

5.0* 

±10ft 

Expected 

Accuracy 

f% Bias) 

10* 

± 5 " 

Completeness 

(%) 

90 

90 

Expected precision and bias for GC-FID analysis of samples obtained using EPA Method 18. Precision 

and bias will be determined for the GC-FID used (Shimadzu GC-14A). 

Headspace measurements eliminated from testing by Project Officer. 

T

 J.U.M. Model VE-7 THC Analyzer with FID. 

n

 Estimated values. 

50 

s^ 
P.60 

Table A-5. Data Quality Indicator Values for Method 18 and THC Measurements Made at Eljer Plumbingware 

(a) Method 18 Measurements in Mobile Lab 

Ca! Gas, % Bias 

6/15/93 

6/16/93 

6/17/93 

6/21/93 

Average 

Precision (% CV) 

2.16 ppm Styrene 

Cal Gas 

(Method 18 Value) 

2.23 

2.23 

2.19 

2.20 

2.21 

0.9 

Bias 

% 

3.2 

3.2 

1.4 

1.9 

2.4 

39.4 ppm Styrene 

Cal Gas 

(Method 18 Value) 

39.4 

39.4 

39.4 

39.4 

39.4 

0.0 

Bias 

% 

0 

0 

0 

0 

0 

170.8 ppm Styrene 

Cal Gas 

(Method 18 Value) 

112.6 

140.5 

136.5 

152.6 

135.3 

12.1 

Bias 

% 

-34 

-18 

-20 

-11 

-21 

(b) THC Measurements Made in Samplinq 

THC#1 

Cal Gas/% Bias 

6/15/93 

6/16/93 

6/17/93 

Average 

Precision (% CV) 

THC #2 

Cal Gas/% Bias 

6/15/93 

6/16/93 

6/17/93 

Average 

Precision (% CV) 

2.16 ppm Styrene 

Cal Gas 

(THC Value) 

3.03 

2.69 

2.51 

2.7 

9.6 

2.16 ppm Styrene 

Cal Gas 

(THC Value) 

2.82 

2.60 

2.58 

2.67 

5.0 

Van, THC'#1 and THC #2 

Bias 

% 

40-

25 

16 

27 

Bias 

% 

31 

20 

19 

24 

170.8 ppm Styrene 

Cal Gas 

(THC Value) 

178.2 

170.8 ppm Styrene 

Cal Gas 

(THC Value) 

174.9 

Bias 

% 

4 

Bias 

% 

• -I 

2 

(c) THC Measurements Made in Mobile Lab. THC #1 and THC #2 

Date 

6/15/93 

6/16/63 

6/17/93 

6/21/93 

Average 

THC#t 

850 ppm Propane 

Cal Gas 

848 

856 

851 

850 

859 

850 

852 

Precision (% CV) I 0.5 

Bias 

% 

•0.2 

. 0.7 

0.1 

0.0 

1.1 

0.00 

0.3 

THC #2 

850 ppm Propane 

Cal Gas 

660 

856 

860 

856 

856 

848 

848 

840 

853 

0.8 

Bias 

% 

1.2 

0.7 

1.2 

0.7 

0.7 

-0.2 

-0.2 

-1.2 

0.4 

51 
P.61 

As with the Method 18 measurements, for the THC analyzers in the sampling van precision was 

determined by repetitive sampling of calibration gases. Because of suspected problems with line losses the 

170.8 ppm calibration gas was only sampled once. Precision was determined by repetitive sampling of the 

2,16 ppm styrene calibration gas. The results of these determinations, shown in Table A-5(b), are within the 

DQI goals shown in Table A-5. 

With respect to the determination of precision for the THC analyzers in the mobile laboratory, these 

i 

analyzers were calibrated with 850 ppm propane. Precision was determined by repetitive sampling of the 

850 ppm propane calibration gas. The results of these determinations, shown in Table A-5(c), are well within 

the DQI goals shown in Table A-4. The relative response of each THC to styrene was determined on June 

i. 

17. After both analyzers had been calibrated with the propane standard, nominal 54 ppm (actual 39.45 ppm) 

styrene calibration gas was fed to both THC analyzers. THC #1 read 115 ppm and THC #2 indicated 116 

ppm. 

Bias 

For Method 18 measurements, bias was much higher than the DQI goal of 10% shown in Table A3. The 2.16 ppm data may be off because the styrene concentration is very low and a small difference in the 

value as determined by the THC can result in a large percentage bias (a 5 ppm concentration of styrene in 

nitrogen was originally ordered). In retrospect, it would have been better to use a higher concentration, in the 

range of 15 ppm. The 170.8 ppm data are also low, by about the same percentage. However, in this case, 

line losses could be partly at fault because some condensation of styrene within a Teflon sample line had 

been observed in the past with this gas. In the air conditioned mobile lab, an unheated 2 m Teflon sample 

line was used. 

For THC analyzer measurements in the sample van, bias was determined for each measurement 

of the 2.16 ppm span gases and is reported in Table A-5(b). At this concentration, average bias values for 

both analyzers were much greater than the target DQI of ± 5%. Partly, this is because a low value of styrene 

was sampled while the THC was calibrated with (what was thought to be) 52 ppm calibration gas. In 

retrospect, it would have been better to use a higher concentration, either lower than the calibration standard 

(in the range of 15 ppm) or higher than the calibration standard (in the range of 100 ppm). The single 

52 

<52^ 
P.62 

sample of 170.8 ppm styrene calibration gas did show a much lower bias for both THC analyzers, below the 

expected DQI of 5%. 

For THC analyzer measurements in the mobile lab, bias was determined for each measurement of 

the 850 ppm propane span gas and is reported in Table A-5(c). As with the values measured for precision, 

bias was very low, averaging less than 0.5% for both THC analyzers. 

Completeness 

For Method 18 samples, completeness was 100%. Some data were not usable because the molds 

that were sprayed during sampling runs when the video cameras malfunctioned could not be used to 

determine emissions per area of mold sprayed, but this was not related to the sampling effort. 

For THC analyzer measurements made in the sampling van, completeness was 50% (for active 

spray booths). This is much lower than the DQI goal of 90%, but, data from these THC analyzers was only 

intended to back up data taken by the other set of THC analyzers in the mobile laboratory. For the THC 

analyzers in the mobile laboratory, a completeness of 91% was achieved (for active spray booths), 

essentially equal to the DQI goal of 90%. Together, both THC analyzers were able to obtain corroborative 

data for every Method 18 sample. With respect to THC samples taken to characterize styrene emissions not 

captured by active spray booths, 100% of the data needed to quantify non-spraying emissions was obtained 

by the THC analyzers in the mobile laboratory. It was not intended to utilize the THC analyzers in the 

sampling van as part of this effort although these instruments were able to contribute some of the emissions 

data measured during work day breaks at the active spray booths. 

Representativeness 

The physical layout of sampling locations at the Eljer facility dictated much of the sampling strategy 

and sampling methodology practiced during this evaluation to obtain representative samples. The use of 

heated sampling lines avoided condensation of styrene and the use of heated Tedlar bags also prevented 

condensation of styrene while the samples were being taken and subsequently analyzed. Location of the 

sampling line inlets near the center of exit vents assured that samples were representative. Following the 

53 

53 
P.63 

sample methodology recommended in EPA Method 18 also assured that representative samples were 

obtained. 

Comparability 

The sampling plan for this project made provision for simultaneous sampling using two 

measurement methods that should allow comparison of the results when suitably averaged over the same 

sampling period. In general, for THC analyzer-based measurements, styrene emissions from the lay-up 

booths and from the gel coat booths were much greater than those determined from Method 18 

measurements. With the exception of the June 17 data, both methods measured essentially the same 

emissions from the single back-up booth. However, these differences do not suggest that the 

measurements are not comparable. Because standard deviations are relatively large for the lay-up and gel 

coat booths, the data do overlap. 

54 

64r 
P.64 

TECHNICAL REPORT DATA 

(Please read Insmtctions on the reverse before completing) 

1. REPORT NO. 

EPA-600/R-96-138 

3. RECIPIENT'S ACCESSION NO. 

4. TITLE ANO SUBTITLE 

Evaluation of Styrene Emissions from a Shower Stall/ 

Bathtub Manufacturing Facility 

5. REPORT DATE 

November 1996 

6. PERFORMING ORGANIZATION CODE 

7. AUTHOR(S) 

Larr y Felix, Randy Merritt, and Ashley Williamson 

8. PERFORMING ORGANIZATION REPORT NO. 

9. PERFORMING ORGANIZATION NAME ANO AOORESS 

Southern Research Institute 

P . O. Box 55305 

Birmingham, Alabama 35355-5305 

10. PROGRAM ELEMENT NO. 

1 1 . CONTRACT/GRANT NO. 

68-D2-0062. Task 12/1 

12. SPONSORING AGENCY NAME ANO AOORESS 

EPA, Office of Research and Development 

Air Pollution Prevention and Control Division* 

Research Triiingle Park, NC 27711 

13. TYPE OF REPORT ANO PERIOD COVERED 

Task Final; 11/93-4/94 

14. SPONSORING AGENCY CODE 

EPA/600/13 

is. SUPPLEMENTARY NOTES APPC D pr0 jec t officer Bobby E. Daniel is no longer with the 

Agency. For details, contact Julian W. Jones, Mail Drop 61, 919/541-2489. (*) Prior 

to April 1, 1995, the Division was the Air and Energy Engineering Research Lab. 

i6. ABSTRACT T | j e re p 0 r t gives results of emissions measurements, carried out at a representative facility (Eljer Plumbingware in Wilson, NC) that manufactures polyesterresin-reinforced shower stalls and bathtubs by spraying styrene-based resins onto 

molds in vented, open, spray booths. Styrene emissions were characterized for the 

three stages of manufacture by measuring styrene concentrations at the vents of 

spray booths used in each part of the process. In addition, styrene concentrations 

were measured at each ventilation fan exhaust. Emission levels were determined 

using EPA Method 18 to obtain integrated emissions samples and total hydrocarbon 

(THC) analyzers to measure continuous emissions levels during the EPA Method 18 

sampling. Analysis of the EPA Reference Method data indicates that: (1) styrene 

monomer is the only volatile organic compound released in the process; (2) overall, 

approximately 4% of all material sprayed is lost to atmospheric emissions as styrene (approximately 19% of all styrene sprayed); and (3) emissions vary for each 

phase of manufacture, with post-spraying emissions of styrene (from curing molds) 

constituting a large part, approximately 29% of all emissions. (NOTE: Current EPA 

emission factors—AP-42—for styrene emissions from the production of polyesterresin-reinforced plastics represent a composite of spraying/post-spraying emissions) 

17. KEY WORDS AND OOCUMENT ANALYSIS 

DESCRIPTORS b.lOENTIFIERS/OPEN ENOEO TERMS c. COSATI Field/Croup 

Pollution 

Styrene 

Styrene Resins 

Emission 

Manufacturing 

Hydrocarbons 

Pollution Control 

Stationary Sources 

Shower Stalls 

Bathtubs 

13 B 

07C 

UI, 11J 

14G 

05C 

18. DISTRIBUTION STATEMENT 

Release to PubUc 

INSECURITY CLASS (ThisReport) 

Uncle s if ied 

2 1 . NO. OF PAGES 

61 

20. SECURITY CLASS (Thispage) 

Unclassified 

22. PRICE 

EPA Form 2220-1 (9-73) 55 
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 

10 

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Publication No. EPA- 600/R-96-138