  SEQ CHAPTER \h \r 1 MEMORANDUM

DATE:	October 28, 2008

SUBJECT:	Model Plants for Paint and Allied Products Manufacturing Area
Sources

  SEQ CHAPTER \h \r 1 

FROM:	Bradley Nelson, EC/R Inc.

TO:		Melissa Payne, EPA/OAQPS/RDPAG   SEQ CHAPTER \h \r 1 

1.0	INTRODUCTION

This memorandum presents the model plants used in the development of
National Emission Standards for Hazardous Air Pollutants (NESHAP) for
the Paint and Allied Products Manufacturing area source category.  The
first section of this memorandum contains a brief background of the
Urban Air Toxics Area Source Program and the listing of the Paint and
Allied Products Manufacturing category.  The following sections discuss
the need for model plants for this source category, and the
characteristics and parameters used to develop the model plants.

2.0	BACKGROUND

Section 112(k) requires the development of standards for area sources
that account for 90% of the emissions of the 30 HAPs listed for urban
areas, as prescribed by the Integrated Urban Air Toxics Strategy (UATS).
 The Paint and Allied Products Manufacturing area source category was
added to the listed categories pursuant to section 112(c)(3) and
112(k)(3)(B)(ii) in November 2002 (67 FR 70427).  The UATS listed the
Paint and Allied Products Manufacturing category as one of the area
sources that accounts for a proportion of the 90% emissions for 6 of the
targeted 30 area source air toxic pollutants: benzene, cadmium,
chromium, lead, methylene chloride, and nickel.  The goals of the UATS
reflect both the statutory requirements stated in Section 112(k) and the
goals of EPA’s overall air toxics program.  

3.0  	NEED FOR MODEL PLANTS

The paint and allied products manufacturing industry comprises of
establishments primarily engaged in the production of paints, inks,
adhesives, stains, varnishes, shellacs, putties, sealers, caulks, and
other coatings which leave a dried film of solid material on a
substrate.  The industry covers several North American Industry
Classification System (NAICS) codes.  These sectors include NAICS codes
325510 (Paint and Coating Manufacturing), 325520 (Adhesive
Manufacturing), 325910 (Printing Ink Manufacturing), and 325998 (All
Other Miscellaneous Chemical Product and Preparation Manufacturing -
Writing and Stamp Ink Manufacturing).  These sectors use similar
processes and raw materials to produce these products, although the size
and production capacity varies from facility to facility.  The 2002
NAICS inventory estimates just over 2,500 facilities nationwide, with
the majority of these facilities producing paints.  The large number of
facilities and the lack of facility-specific information resulted in the
need to develop model plants to represent the source category.  These
model plants will be used to develop facility emissions, which in turn
will be used to assess control options and regulatory alternatives
considered by EPA.

4.0	CHARACTERISTICS OF MODEL PLANTS

	The main characteristics used to define model plants for the Paint and
Allied Products Manufacturing source category include the production
capacity, number of process vessels, and the HAP emissions from the
facility.  The 2002 economic census for each of the sectors was used to
determine production capacity.  Information from the state permits was
used to estimate the number of process vessels at each facility, and
AP-42 emissions factors and data from the 2002 NEI database were used to
estimate HAP emissions from the facilities.  A discussion of the methods
and the specific data used to develop these model plants is presented in
the following sections.

4.1	Industry Census Data

	The inventory for the paint and allied products manufacturing industry
was obtained from the 2002 economic census for each of the NAICS
industries.  The census lists an inventory of 2,510 paint and allied
product manufacturing facilities.  Table 1 provides a breakdown of the
number of facilities, number of employees, and total value of shipments
for the paint and allied products manufacturing data from the 2002 U.S.
Economic Census.  As the table shows, 62.6% of the paint and allied
products manufacturing facilities have less than 20 employees, but these
facilities only contributed 10.4% of the total sales.  These small
facilities are typically regional paint companies that supply local
hardware stores or home repair centers, or provide specialty coatings to
local industries.  A graphical summary of the combined economic census
data is provided in Figure 1.  As the economic census data show, the
slope of the total value of shipments increases after the 10 to 19
employee range.  At this point the total value of shipments per employee
increases from approximately $300,000 per employee to $400,000 per
employee.  

	This value of shipments per employee appears to be a natural division
which can be used to separate the facilities into two groups; facilities
with 19 employees or less, and facilities with 20 employees or greater
for the purpose of developing model plants.  Therefore, we designated
facilities with 19 employees or less as small model plants, and
facilities with 20 employees or more as large model plants.  Therefore,
the census data for 1 to 19 employees was used to represent small model
plants, and would account for 1,572 of the manufacturing facilities,
which are all assumed to be area sources.  For the large model plants,
we believe the value of shipments and production capacity of the 20 to
99 employee’s census data is more representative of area sources in
the large model plant category.  Therefore, the large model plants would
account for the other 618 area source facilities, and are assumed to
have 20 or more employees.  These small and large model plant groups
will be used to represent the area sources for the paint and allied
products manufacturing source category.  Since this rule covers only
area sources, there will be no model plant for the 320 major sources.

Table 1.  Summary of 2002 U.S. Census Data from Paint and Allied
Products Manufacturing Facilities1

Employment Size	Total Number of Facilities	Number of Employees	Total
Value of Shipments ($1,000)	Value of Shipments per Employee ($/employee)

1 to 4 employees	738	1,627	466,806	286,912

5 to 9 employees	387	2,650	929,154	350,624

10 to 19 employees	447	6,249	1,791,827	286,738

20 to 49 employees	522	16,526	5,281,405	319,582

50 to 99 employees	229	15,750	6,203,445	393,870

100 to 249 employees	157	24,164	10,675,531	441,795

250 to 499 employees	26	8,365	3,848,185	460,034

500 to 999 employees	3	2,250	1,134,083	504,037

1,000 to 2,499 employees	1	1,161	381,459	328,561

Total	2,510	78,702	30,701,138	390,093







1 to 19 employees	1,572	10,526	3,187,787	302,849

20 to 2,499 employees	938	68,216	27,524,108	403,484

1 Data Source: 2002 Economic Census for Paint and Coating Manufacturing,
Adhesive Manufacturing, Printing Ink Manufacturing, and All Other
Miscellaneous Chemical and Preparation Manufacturing.

Figure 1.  Graphical Representation of Economic Census Data 

for the Paint and Allied Products Manufacturing Industry1

1 Data Source: 2002 Economic Census for Paint and Coating Manufacturing,
Adhesive Manufacturing, Printing Ink Manufacturing, and All Other
Miscellaneous Chemical and Preparation Manufacturing.

4.2	Production Capacity

	Data from the 2002 economic census for each of the NAICS sectors was
used to estimate the production capacity.  The economic census provides
information on the number of facilities, number of employees, and the
total value of shipments from the facility.  To determine the quantity
of paint produced by each facility, data from the Current Industrial
Report for the paint and allied products manufacturing category was
used.  The industrial report provides total quantity and total value of
shipments of paint and allied products.  The report states the total
quantity of paint and allied products produced in 2002 was 1,433,900,000
gallons at a total value of $17,465,800,000.  To estimate the total
value per gallon of paint, the total value was divided by the total
number of gallons.  This calculates to $12.18 per gallon of paint and
allied products produced.  Using this factor and the total value of
shipments listed in the U.S. Census, we can estimate the annual
production for each of the facility employee size categories using the
following equation;

Estimated Annual Production = [Value of Shipments $/year]/[$12.18/gal of
product]

	Where:

	Value of Shipments is the total value of shipments listed in the U.S.
Census for each of 	the employee size categories, and; 

	$12.18 is the estimated value of the paint and allied products
calculated using data from 	the Current Industrial Report produced by
the U.S Census Bureau.

   

The following table provides a summary of the total value and estimated
production of paint and allied products.

Table 2.  Summary of 2002 U.S. Census Data and Estimated Production from
Paint and Allied Products Manufacturing Facilities1

Employment Size	Total Number of Facilities	Total Value of Shipments
($1,000)	Total Estimated Production (gal/yr)	Estimated Production Per
Facility (gal/yr)

1 to 4 employees	738	466,806	38,323,645	51,929

5 to 9 employees	387	929,154	76,281,299	197,109

10 to 19 employees	447	1,791,827	147,104,669	329,093

20 to 49 employees	522	5,281,405	433,590,596	830,633

50 to 99 employees	96	2,600,571	213,511,576	2,224,079







Small Model Plant 

(1 to 19 employees)	1,572	3,187,787	261,709,613	166,482

Large Model Plant 

(20  or more employees)	618	7,881,976	647,102,172	1,047,090

1 Data Source: 2002 Economic Census for Paint and Coating Manufacturing,
Adhesive Manufacturing, Printing Ink Manufacturing, and All Other
Miscellaneous Chemical and Preparation Manufacturing.

	Of the two model plants categories, the small model plant, with 19
employees or less, is the most common paint and allied products
manufacturing facility.  The small model plant is estimated to produce
almost 167,000 gallons of paint and allied products per year.  The large
model plants are facilities with 20 or more employees and are estimated
to produce about 1,050,000 gallons of coatings per year.  Facilities
with 100 or more employees are assumed to be major sources and are not
modeled in this memorandum.

4.3	HAP Emissions

	Emissions from the model plants were calculated using the small and
large model plant production estimate and AP-42 emissions factors.  The
AP-42 emission factors only provide emission estimates for volatile
organic compounds (VOC) and particulate matter (PM); therefore data from
the NEI database were used to develop factors to estimate the fraction
of VOC and PM that is HAP.  The AP-42 emission factor for VOC is listed
as 1.5 lbs/100 lbs of product.  A density of 12.5 lbs/gal of product was
used to convert the estimated volume production of the model plants to a
weight based production.  The calculated weight based production was
multiplied by the emission factor to determine the VOC emissions from
the model plant.  For the small model plant, the VOC emissions were
calculated to be 15.7 Tons/yr, and the VOC emissions for the large model
plant were calculated to be 98.4 Tons/yr.  A summary of the VOC
emissions is presented in Table 2.

	The fraction of HAP in the VOC emissions was calculated using the 2002
NEI data for sources that provided both VOC and HAP data.  The average
fraction of HAP in the VOC total was calculated to be 0.0989.  A summary
of the VOC and HAP emissions rates is presented in Table 3.  The HAP
emission totals from the 2002 NEI data were used to calculate the
fraction of HAP that is volatile and the fraction of HAP that is
particulate.  The fraction of volatile HAP in the total HAP was
calculated to be 0.9976, and the fraction of total HAP that is
particulate HAP was calculated to be 0.0024.  These fractions were used
to estimate the total, volatile, and particulate HAP emissions from the
model plants.  A summary of these HAP emissions are presented in Table
3.

	PM emissions were calculated using the model plant production data and
the AP-42 emissions factor for PM.  The AP-42 emission factor for PM is
listed as 20 lb/ton of pigment used.  To estimate the amount of pigment
used by the model plant, we looked at the densities of the raw materials
and the product to calculate the amount of pigment in the coating
product.  Using a coating density of 12.5 lb/gal (average density of
produced coating), a density of 33.4 lb/gal for titanium dioxide (a
common pigment), and a solvent density of 7.2 lb/gal for xylene ( a
common solvent), the fraction of pigment in the product coating was
calculated to be 0.20.   Using this fraction, a pigment density of 33.4
lb/gal, and model plant production, the annual pigment usage for the
small model plant was calculated to be 558 tons/yr, and the pigment
usage for the large model plant was estimated to be 3,507 tons/yr.  An
example of the PM emission calculation for the small model plants is as
follows;

Small Model Plant PM Emissions = [167,000 gal/yr]*[0.20]*[33.4
lb/gal]*[Ton/2000 lb]

*[20 lb/Ton of pigment]*[Ton/2000 lb]

Where:

167,000 gal/yr is the estimated production from the small model plant,

0.20 is the fraction of pigment in the paint or allied products,

33.4 lb/gal is the density of the pigment,

Ton/2000 lb is the conversion factor to convert pounds to tons,

20 lb/Ton if pigment is the AP-42 PM emission factor for paint and
allied products, and

Ton/2000 lb is the conversion factor to convert pounds to Tons.

	In addition to HAP, fine particulate matter that is 2.5 micrometers in
diameter and smaller (PM2.5) is also a concern to for both worker and
public health.  Emissions of PM2.5 were estimated using speciation data
provided in the EPA Emissions Modeling Clearinghouse.  Using the Source
Classification Codes (SCC) for paint, varnish, adhesive, and inks
manufacturing, the mass fraction of PM that is PM2.5 were determined for
each of these segments.  For paint and varnish manufacturing, the mass
fraction of PM that is PM2.5 is 0.3995, and for ink and adhesive
manufacturing the mass fraction of PM that is PM2.5 is 0.5624.  To
determine the PM2.5 emissions from the model plants, a facility weighted
average mass fraction was calculated using the total number of area
source facilities and the total number of the area source paint and
varnish and ink and adhesive facilities.  The facility weighted mass
fraction was calculated to be 0.474 and will be used to estimate the
PM2.5 emissions for the model plants.  A summary of the PM2.5 emissions
is shown in Table 3. 

Table 3.  Summary of HAP, PM, and VOC Emissions from the 

Paint and Allied Products Manufacturing Model Plants

Model Plant	Estimated Plant Production (Gal/yr)	Estimated Pigment Usage
(Tons/yr) 	PM Emissions

(Tons/yr)	PM2.5 Emissions

(Tons/yr)	VOC Emissions (Tons/yr)	HAP Emissions (Tons/yr)	Volatile HAP
Emissions (Tons/yr)	Particulate HAP Emissions (Tons/yr)

Small	167,000	558	5.58	2.64	15.7	1.549	1.545	0.004

Large	1,050,000	3,507	35.1	16.6	98.4	9.733	9.710	0.023



4.4	Process Vessels

For the paint and allied products manufacturing sector, process vessels
are used to combine the raw materials for mixing into the desired
coating.  These process vessels are the main source of HAP emissions
from the paint and allied products manufacturing facilities, which occur
during the addition of the raw materials, mixing of the raw materials
into the final product, and the evaporation of the volatile chemicals. 
To determine the number of process vessels used at paint and allied
products manufacturing facilities, we looked at the State permit data. 
The permits provided process vessel inventory data for 12 facilities; 5
area sources and 7 major sources.  The process vessels were divided into
two groups, storage vessels and mixing vessels.  Storage vessels are
used to store raw materials for use in the coating production process. 
Mixing vessels are used to combine the raw materials into the coating
product.  The size of the process vessels range from 5 to 20,000 gallons
and can be stationary or portable. A summary of the average number of
process vessels per paint and allied products manufacturing facility is
presented in Table 4.  

For purposes of estimating the number of process vessels used at the
model plants, we assumed that the small model plant would be similar to
the area source process vessel count described in the State permits. 
Therefore, it was assumed that there are 17 process mixing vessels used
at small model plants.  Similarly, we believe that the average number of
process vessels from the major source facilities is comparable to the
number of process vessels at a large model plant.  While these process
vessel counts are from major source facilities, we believe this process
vessel count is representative of the number of process vessels at large
area sources. Therefore, the large model plants are assumed to have 129
process mixing vessels.  

5.0	MODEL PLANT SUMMARY

	The model plants described in this memorandum will be used to estimate
facility emissions, develop control options, and calculate the cost of
regulatory alternatives for the Paint and Allied Products Manufacturing
area source sector.  A brief summary of the model plants are described
in the following sections.

5.1	Small Model Plants

	The small model plant developed in this memorandum describes the
majority of area source facilities in the Paint and Allied Products
Manufacturing category.  The small model plant will describe paint and
allied products manufacturing facilities with 19 employees or less. 
This small model plant will describe the production of 1,572 of the
2,190 area source facilities.  This plant will be assumed to produce
167,000 gallons of coatings a year, with a pigment usage of 558 tons/yr.
 The small model plant is also assumed to use 17 process mixing vessels
in the production of the coatings.  The HAP emissions from the small
model plant facility are estimated to be 1.549 Tons/yr.

5.2	Large Model Plants

	The large model plant developed in this memorandum describes the
remaining area source facilities in the Paint and Allied Products
Manufacturing category.  The large model plant describes facilities with
20 to 99 employees and comprises of 618 of the 2,190 area source
facilities.  This large model plant will be assumed to produce 1,050,000
gallons of coatings a year, with a pigment usage of 3,507 tons/yr.  The
large model plant is also assumed to use 129 process mixing vessels in
the production of the coatings.  The HAP emissions from the large model
plant facility are estimated to be 9.733 Tons /yr.

Table 4.  Average Number of Process Vessels Used at Paint and Allied
Products Manufacturing Facilities1

Process Vessel Type

Process Vessel Size (gallons)

	50	51 - 100	101 - 200	201 - 500	501 - 1000	1001 - 2500	2501 - 5000	5001
– 10,000	10,001 – 20,000	>20,000	Total

Minor Sources

Storage	0	2	3	4	4	2	3	6	0	1	25

Mixing	1	1	1	2	5	6	1	0	0	0	17

Major Sources

Storage	1	0	1	1	8	14	13	6	6	1	51

Mixing	13	30	14	46	14	10	1	1	0	0	129

1 Data Source: State permits.

2 Average of data from 5 facility permits.

3 Average of data from 7 facility permits.

 The 2002 NAICS codes and industry descriptions were obtained from the
U.S. Census website, http://www.census.gov/epcd/www/naics.html.

 2002 Economic Census, Industry Series, US Department of Commerce, US
Census Bureau. http://www.census.gov/econ/census02/guide/INDRPT31.HTM

 Current Industrial Report, Paints and Allied Products: 2005, US
Department of Commerce, Economics and Statistics Administration, June
2006. http://www.census.gov/industry/1/ma325f05.pdf

 Emissions Modeling Clearinghouse, Speciation,
http://www.epa.gov/ttnchie1/emch/speciation/index.html.

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