Appendix A Listing of All HAPs
 
Appendix A. Listing of HAPs

CAS Number Chemical Name Common Name CAA HAP TRI Chemic

75-07-0 Acetaldehyde XX 60-35-5 Acetamide X X75-05-8 Acetonitrile X X98-86-2 Acetophenone X X53-96-3 2-Acetylaminofluorene X X107-02-8 Acrolein XX 79-06-1 Acrylamide X X79-10-7 Acrylic acid X X107-13-1 Acrylonitrile XX 107-05-1 Allyl chloride X X92-67-1 4-Aminobiphenyl X X62-53-3 Aniline X X90-04-0 o-Anisidine X X1332-21-4 Asbestos X X71-43-2 Benzene (including benzene from gasoline) XX 92-87-5 Benzidine X X98-07-7 Benzotrichloride X X100-44-7 Benzylchloride X X92-52-4 Biphenyl X X117-81-7 Bis (2-ethylhexyl) phthalate DEHP X X542-88-1 Bis(chloromethyl )ether X X75-25-2 Bromoform X X106-99-0 1,3-Butadiene XX 156-62-7 Calcium cyanamide X X133-06-2 Captan X X63-25-2 Carbaryl X X75-15-0 Carbon disulfide X X56-23-5 Carbon tetrachloride XX 463-58-1 Carbonyl sulfide X X120-80-9 Catechol X X133-90-4 Chloramben X X57-74-9 Chlordane X X7782-50-5 Chlorine X X79-11-8 Chloroacetic acid X X532-27-4 2-Chloroacetophenone X X108-90-7 Chlorobenzene X X510-15-6 Chlorobenzilate X X67-66-3 Chloroform XX 107-30-2 Chloromethyl methyl ether X X126-99-8 Chloroprene X X1319-77-3 Cresol/Cresylic acid (mixed isomers) X X

April 2004 
Appendix A. Listing of HAPs

CAS Number Chemical Name Common Name CAA HAP TRI Chemic

95-48-7 o-Cresol X X108-39-4 m-Cresol X X106-44-5 p-Cresol X X98-82-8 Cumene X XN/A 2,4-Dichlorophenoxyacetic Acid (including salts and esters) 2-4-D X72-55-9 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene DDE X334-88-3 Diazomethane X X132-64-9 Dibenzofuran X X96-12-8 1,2-Dibromo-3-chloropropane X X84-74-2 Dibutyl phthalate X X106-46-7 1,4-Dichlorobenzene X X91-94-1 3,3'-Dichlorobenzidine X X111-44-4 Dichloroethylether Bis[2-chloroethyl]ether X X542-75-6 1,3-Dichloropropene XX 62-73-7 Dichlorvos X X111-42-2 Diethanolamine X X64-67-5 Diethyl sulfate X X119-90-4 3,3'-Dimethoxybenzidine X X60-11-7 4-Dimethylaminoazobenzene X X121-69-7 N,N-Dimethylaniline X X119-93-7 3,3'-Dimethylbenzidine X X79-44-7 Dimethylcarbamoyl chloride X X68-12-2 N,N-Dimethylformamide X X57-14-7 1,1-Dimethylhydrazine X X131-11-3 Dimethyl phthalate X X77-78-1 Dimethyl sulfate X XN/A 4,6-Dinitro-o-cresol (including salts) X51-28-5 2,4-Dinitrophenol X X121-14-2 2-4-Dinitrotoluene X X123-91-1 1,4-Dioxane 1,4-Diethyleneoxide X X122-66-7 1,2-Diphenylhydrazine X X106-89-8 Epichlorohydrin l-Chloro-2,3-epoxypropane X X106-88-7 1,2-Epoxybutane X X140-88-5 Ethyl acrylate X X100-41-4 Ethylbenzene XX 51-79-6 Ethyl carbamate Urethane X X75-00-3 Ethyl chloride Chloroethane X X106-93-4 Ethylene dibromide Dibromoethane XX 107-06-2 Ethylene dichloride 1,2-Dichloroethane XX 107-21-1 Ethylene glycol X X151-56-4 Ethyleneimine Aziridine X X

April 2004 
Appendix A. Listing of HAPs

CAS Number Chemical Name Common Name CAA HAP TRI Chemic

75-21-8 Ethylene oxide XX 96-45-7 Ethylene thiourea X X75-34-3 Ethylidene dichloride 1-1-Dichloroethane X X50-00-0 Formaldehyde XX 76-44-8 Heptachlor X X118-74-1 Hexachlorobenzene XX 87-68-3 Hexachlorobutadiene X XN/A 1,2,3,4,5,6-Hexachlorocyclohexane (all stereoisomers-including lindane) X77-47-4 Hexachlorocyclopentadiene X X67-72-1 Hexachloroethane X X822-06-0 Hexamethylene diisocyanate X680-31-9 Hexamethylphosphoramide X X110-54-3 Hexane XX 302-01-2 Hydrazine XX 7647-01-0 Hydrochloric acid Hydrogen Chloride X X7664-39-3 Hydrogen fluoride Hydrofluoric acid X X123-31-9 Hydroquinone X X78-59-1 Isophorone X108-31-6 Maleic anhydride X X67-56-1 Methanol X X72-43-5 Methoxychlor X X74-83-9 Methyl bromide Bromomethane X X74-87-3 Methyl chloride Chloromethane X X71-55-6 Methyl chloroform 1-1-1-Trichloroethane X X78-93-3 Methyl ethyl ketone 2-Butanone X X60-34-4 Methyl hydrazine X X74-88-4 Methyl iodide Iodomethane X X108-10-1 Methyl isobutyl ketone Hexone X X624-83-9 Methyl isocyanate X X80-62-6 Methyl methacrylate X X1634-04-4 Methyl tert-butyl ether MTBE XX 101-14-4 4,4'-Methylenebis 2-chloroaniline X X75-09-2 Methylene chloride Dichloromethane XX 101-68-8 4-4'-Methylenediphenyl diisocyanate MDI X101-77-9 4-4'-Methylenedianiline X X91-20-3 Naphthalene XX 98-95-3 Nitrobenzene X X92-93-3 4-Nitrobiphenyl X X100-02-7 4-Nitrophenol X X79-46-9 2-Nitropropane X X684-93-5 N-Nitroso-N-methylurea X X

April 2004 
Appendix A. Listing of HAPs

CAS Number Chemical Name Common Name CAA HAP TRI Chemic

62-75-9 N-Nitrosodimethylamine X X59-89-2 N-Nitrosomorpholine X X56-38-2 Parathion X X82-68-8 Pentachloronitrobenzene Quintobenzene X X87-86-5 Pentachlorophenol X X108-95-2 Phenol X X106-50-3 p-Phenylenediamine X X75-44-5 Phosgene X X7803-51-2 Phosphine X X7723-14-0 Phosphorus X X85-44-9 Phthalic anhydride X X1336-36-3 Polychlorinated biphenyls Aroclors XX 1120-71-4 1-3-Propane sultone X X57-57-8 beta-Propiolactone X X123-38-6 Propionaldehyde X X114-26-1 Propoxur Baygon X X78-87-5 Propylene dichloride 1,2-Dichloropropane XX 75-56-9 Propylene oxide X X75-55-8 1-2-Propylenimine 2-Methylaziridine X X91-22-5 Quinoline XX 106-51-4 Quinone p-Benzoquinone X X100-42-5 Styrene XX 96-09-3 Styrene oxide X X1746-01-6 2,3,7,8-Tetrachlorodibenzo-p-dioxin X 79-34-5 1,1,2,2-Tetrachloroethane XX 127-18-4 Tetrachloroethylene Perchloroethylene XX 7550-45-0 Titanium tetrachloride X X108-88-3 Toluene XX 95-80-7 Toluene-2,4-diamine X X584-84-9 2,4-Toluene diisocyanate X X95-53-4 o-Toluidine X X8001-35-2 Toxaphene chlorinated camphene X X120-82-1 1,2,4-Trichlorobenzene X X79-00-5 1,1,2-Trichloroethane X X79-01-6 Trichloroethylene XX 95-95-4 2-4-5-Trichlorophenol X X88-06-2 2-4-6-Trichlorophenol X X121-44-8 Triethylamine X X1582-09-8 Trifluralin X X540-84-1 2,2,4-Trimethylpentane X108-05-4 Vinyl acetate X X

April 2004 
Appendix A. Listing of HAPs

CAS Number Chemical Name Common Name CAA HAP TRI Chemic

593-60-2 Vinyl bromide X X75-01-4 Vinyl chloride XX 75-35-4 Vinylidene chloride 1,1-Dichloroethylene X X1330-20-7 Xylenes (mixed isomers) XX 95-47-6 o-Xylene X X108-38-3 m-Xylene X X106-42-3 p-Xylene X X

Antimony Compounds X XArsenic Compounds (inorganic including arsine) XX Beryllium Compounds XX Cadmium Compounds XX Chromium Compounds XX Cobalt Compounds X XCoke Oven Emissions X Cyanide Compounds 1 X X

Glycol ethers 2 XLead Compounds XX Manganese Compounds XX Mercury Compounds XX Fine mineral fibers 3 X

Nickel Compounds XX Polycyclic Organic Matter 4 XX 

Radionuclides (including radon) 5 X

Selenium Compounds X X

3 Includes mineral fiber emissions from facilities manufacturing or processing glass, rock or slag fibers (or other mineral derived fibers) or average diamete5 A type of atom which spontaneously undergoes radioactive decay.1 X'CN where X=H or any other group where a formal dissociation may occur. For example KCN or CA(CN)2.2 Includes mono- and di- ethers of ethylene glycol, diethylene glycol, triethylene glycol R-(OCH2CH2)n-OR where n= 1,2, or 3; R= alkyl or aryl groups; R' = removed, yield glycol ethers with the structure: R-(OCH2CH)n-OH. Polymers are excluded from the glycol category. 4 Includes organic compounds with more than one benzene ring, and which have a boiling point greater than or equal to 100 degrees C.

April 2004 
April 2004 Page B-1

Appendix B Guide to Federal Agencies that Oversee

Air Toxics

This appendix contains descriptions and contacts of the primary EPA organizations that routinely

deal with air toxics risk related regulations and information. Additional governmental offices

that also deal with air toxics information are also listed. This listing is not meant to be either

comprehensive or static and updates and suggestions for additions are welcome (email to

mitchell.ken@epa.gov). 

The listing is arranged first by EPA headquarters offices and contacts that deal specifically with

air toxics risk related issues. EPA Regional air toxics contacts and other governmental agencies

that provide health and risk assessment information complete the listing.

1. EPA Headquarters Offices that Work Directly on Air Toxics Issues

a. Office of Air and Radiation. The Office of Air and Radiation (OAR) develops national

programs, technical policies, and regulations for controlling air pollution and radiation

exposure. OAR is concerned with energy conservation and pollution prevention, indoor

and outdoor air quality, industrial air pollution, pollution from vehicles and engines,

radon, acid rain, stratospheric ozone depletion, and radiation protection. 

http://www.epa.gov/air

There are three main offices within OAR that work on air toxics issues - OAQPS, OTAQ,

and ORIA.

i. Office of Air Quality Planning and Standards (OAQPS). OAQPS primary

mission is to preserve and improve air quality in the United States. OAQPS, as part of

this goal, monitors and reports on air quality, air toxics, and emissions. They also

watch for visibility issues, as they relate to the level of air pollution. In addition,

OAQPS is tasked by the EPA with providing technical information for professionals

involved with monitoring and controlling air pollution, creating governmental

policies, rules, and guidance for professionals and government, and educating the

public about air pollution and what can be done to control and prevent it. 

http://www.epa.gov/air/oaqps/index.html

ii. Office of Transportation and Air Quality (OTAQ). OTAQ protects public health

and the environment by controlling air pollution from motor vehicles, engines, and

the fuels used to operate them, and by encouraging travel choices that minimize

emissions. These “mobile sources” include cars and light trucks, large trucks and

buses, nonroad recreational vehicles (such as dirt bikes and snowmobiles), farm and

construction equipment, lawn and garden equipment, marine engines, aircraft, and

locomotives. http://www.epa.gov/otaq/

iii. Office of Radiation and Indoor Air (ORIA). The mission of ORIA is to protect the

public and the environment from the risks of radiation and indoor air pollution. The
April 2004 Page B-2

programs within EPA and other agencies to control radiation and indoor air pollution

exposures; provides technical assistance to states through EPA’s regional offices, and

to other agencies having radiation and indoor air protection programs; directs an

environmental radiation monitoring program; responds to radiological emergencies;

and evaluates and assesses the overall risk and impact of radiation and indoor air

pollution. http://www.epa.gov/air/oria.html

b. Office of Pollution Prevention and Toxics (OPPT). OPPT has the primary

responsibility for administering the Toxic Substances Control Act (TSCA) and the

Pollution Prevention Act of 1990. It also manages the Chemical Right-to-Know

Initiative and the New and Existing Chemicals programs; the Design for the Environment

(DFE), Green Chemistry, and Environmentally Preferable Products (EPP) programs; and

the Lead, Asbestos, and Polychlorinated Biphenyls (PCBs) program. 

http://www.epa.gov/opptintr/.

c. Office of Research and Development (ORD). The U.S. Environmental Protection

Agency (EPA) relies on sound science to safeguard both human health and the

environment. The Office of Research and Development (ORD) is the scientific research

arm of EPA. ORD’s leading-edge research helps provide the solid underpinning of

science and technology for the Agency. ORD conducts research on ways to prevent

pollution, protect human health, and reduce risk. The work at ORD laboratories, research

centers, and offices across the country helps improve the quality of air, water, soil, and

the way we use resources. Applied science at ORD builds our understanding of how to

protect and enhance the relationship between humans and the ecosystems of Earth. 

www.epa.gov/ord

i. Office of Science Policy (OSP). The OSP integrates and communicates scientific

information generated by or for ORD’s laboratories and centers, as well as ORD’s

expert advice on the use of scientific information. EPA and the scientific community

at large use this information to ensure that EPA’s decisions and environmental

policies are informed by sound science. http://www.epa.gov/osp/

ii. The National Center for Environmental Assessment (NCEA). NCEA is EPA’s

national resource center for human health and ecological risk assessment. NCEA

conducts risk assessments, carries out research to improve the state-of-the-science of

risk assessment, and provides guidance and support to risk assessors. 

www.epa.gov/ncea

iii. National Exposure Research Laboratory (NERL). NERL is comprised of several

divisions with diversified research specialties. NERL conducts research and

development that leads to improved methods, measurements and models to assess and

predict exposures of humans and ecosystems to harmful pollutants and other

conditions in air, water, soil, and food. www.epa.gov/nerl/

iv. National Health and Environmental Effects Research Laboratory (NHEERL). 

NHEERL is the Agency’s focal point for scientific research on the effects of

contaminants and environmental stressors on human health and ecosystem integrity.

Its research mission and goals help the Agency to identify and understand the
April 2004 Page B-3

processes that affect our health and environment, and helps the Agency to evaluate

the risks that pollution poses to humans and ecosystems. The impact of NHEERL’s

efforts can be felt far beyond the EPA, by enabling state and local governments to

implement effective environmental programs, assisting industry in setting and

achieving environmental goals, and collaborating with international governments and

organizations on issues of environmental importance. http://www.epa.gov/nheerl/

v. National Risk Management Research Laboratory (NRMRL). NRMRL conducts

research into ways to prevent and reduce pollution risks that threaten human health

and the environment. The laboratory investigates methods to prevent and control

pollution of air, land, and water, and to restore ecosystems. The goals of this research

are to develop and promote technologies that protect and improve the environment;

develop scientific and engineering information to support regulatory and policy

decisions; and provide technical support and information transfer to ensure

implementation of environmental regulations and strategies at the national and

community levels. In addition, NRMRL collaborates with both public and private

sector partners to anticipate emerging problems and to foster technologies that reduce

the cost of compliance. http://www.epa.gov/ORD/NRMRL/

2. EPA Headquarters Offices that Work on Specific Air Toxics Risk Issues

a. OAQPS Risk and Exposure Assessment Group (REAG). The REAG maintains the

scientific and analytical expertise necessary to conduct human and ecological air toxics

risk assessments and develop new assessment methodologies, guidelines, and policies for

air toxics risk assessments, risk characteristics, and risk communication. The Group also

serves as a center of air toxics health risk information for Regional, State, and local

agencies. http://www.epa.gov/oar/oaqps/organization/esd/reag.html

b. OAQPS Air Quality Modeling Group (AQMG). The Air Quality Modeling Group is

responsible for providing leadership and direction on the full range of atmospheric

dispersion models and other mathematical simulation techniques used in assessing source

impacts and control strategies. The Group serves as the focal point on modeling

techniques for other EPA headquarters staff, Regional Offices, and State and local

agencies. It coordinates with ORD on the development of new models and techniques, as

well as wider issues of atmospheric research. Finally, the Group conducts modeling

analyses to support policy/regulatory decisions in OAQPS. 

http://www.epa.gov/air/oaqps/organization/emad/aqmg.html

c. OAQPS Emission Factors and Inventories Group (EFIG). Emission inventories are

the basis for numerous efforts including trends analysis, regional, and local scale air

quality modeling, regulatory impact assessments, and human exposure modeling. These

inventories are used in analyses by EPA, State and local agencies, as well as the public.

As a central depository for emission facts, inventory data and factor and inventory

development references, the EFIG is responsible for providing technical assistance to

Regional, State, and local clients. Through this working relationship, inventories are
April 2004 Page B-4

developed to meet the emerging needs of all their users. 

http://www.epa.gov/air/oaqps/organization/emad/efig.html

d. OAQPS Monitoring and Quality Assurance Group (MQAG). MQAG is responsible

for identifying ambient monitoring needs based on OAQPS’ data requirements, and for

developing the monitoring program and quality assurance infrastructure to support these

requirements with the highest quality ambient air data. 

http://www.epa.gov/air/oaqps/organization/emad/mqag.html

e. OAQPS Policy, Planning, and Standards Group (PPSG). The PPSG, which is in the

Emissions Standards Division of OAQPS, facilitates planning and development of

Division activities and integration of Division programs with other OAQPS and EPA

programs. The group is responsible for developing and implementing national emission

standards, new source performance standards, control techniques guidelines, regulatory

review programs, and other technical documents for specific categories of stationary

sources of hazardous and criteria air pollutants. Finally, the Group performs

comprehensive analyses of hazardous and criteria air pollutant emissions and control

measures for the specified categories of stationary sources. Such analyses typically form

the basis for national emission standards or technical guidance documents. 

http://www.epa.gov/oar/oaqps/organization/esd/ppsg.html

f. OTAQ Air Toxics Center. The Air Toxics Center is OTAQ’s resource on mobile

source air toxics and other mobile source-related human health and welfare issues. The

Center provides expertise on mobile source air toxic emissions, exposure and risk to the

Agency. It helps regulators and the public understand the risk from mobile source air

toxics to human health and welfare. It also develops mobile source-related air toxics

regulations, and addresses air toxics impacts of all mobile source control programs. In

addition, it develops information, tools and resources to empower states, communities

and individuals to make and implement their own decisions about air toxics. Finally, the

Center works to influence the toxics research agenda and strategies of parties internal and

external to EPA in order to advance OTAQ’s mission. www.epa.gov/otaq/toxics.htm
April 2004 Page B-5

3. EPA Regional Air Toxics Contacts

Region 1

FUNCTION NAME TELEPHONE

Maximum Achievable Control

Technology (MACT)

Susan Lancey 617-918-1656

Toxics Emissions Inventory Bob McConnell 617-918-1046

Air Deposition Ian Cohen 617-918-1655

Air Dispersion/ Deposition

Modeling

Brian Hennessey 617-918-1654

Monitoring Peter Kahn 781-860-4392

Community Assessments Marybeth Smuts 617-918-1512

Risk Assessment Marybeth Smuts 617-918-1512

Mobile Sources Robert Judge 617-918-1045

Indoor Air Eugene Benoit 617-918-1639
April 2004 Page B-6

Region 2

FUNCTION NAME TELEPHONE

Maximum Achievable Control

Technology (MACT)

Umesh Dholakia 212-637-4023

Toxics Emissions Inventory Raymond Forde 212-637-3716

Air Deposition Bob Kelly 212-637-3709

Air Dispersion/ Deposition

Modeling

Bob Kelly 212-637-3709

Monitoring Mazeeda Khan

Avi Teitz

212-637-3715

732-906-6160

Community Assessments Carol Bellizzi

Marlon Gonzales

212-637-3712

212-637-3769

Risk Assessment Gina Ferreira

Carol Bellizzi

212-637-3768

212-637-3712

Mobile Sources Reema Persaud 212-637-3760

Indoor Air Larainne Koehler 212-637-4005
April 2004 Page B-7

Region 3

FUNCTION NAME TELEPHONE

Maximum Achievable Control

Technology (MACT)

Ray Chalmers 215-814-2061

Air Deposition Al Cimorelli 215-814-2189

Air Dispersion/Deposition

Modeling

Al Cimorelli 215-814-2189

Monitoring Ted Erdman 215-814-2766

Community Assessments Helene Drago 215-814-5796

Risk Assessment Alvaro Alvarado 215-814-2109

Mobile Sources Brian Rehn 215-814-2176

Indoor Air Fran Dougherty

Cristina Schulingkamp

215-814-2083

215-814-2086
April 2004 Page B-8

Region 4

FUNCTION NAME TELEPHONE

Maximum Achievable Control

Technology (MACT)

Lee Page 404-562-9131

Toxics Emissions Inventory Leonardo Ceron 404-562-9129

Air Deposition Dr. John Ackermann

Latoya Miller

404-562-9063

404-562-9885

Air Dispersion/Deposition

Modeling

Stan Krivo

Rick Gillam

404-562-9123 

404-562-9049

Monitoring Van Shrieves

Danny France

404-562-9089

706-355-8738

Community Assessments Paul Wagner 404-562-9100

Risk Assessment Dr. Kenneth Mitchell (human

health/ecological)

Dr. Solomon Pollard (human health)

Ofia Hodoh (human health)

Dr. John Ackermann (ecological)

Latoya Miller (ecological)

404-562-9065

404-562-9180

404-562-9176

404-562-9063

404-562-9885

Mobile Sources Dale Aspy 404-562-9041

Indoor Air Henry Slack 404-562-9143
April 2004 Page B-9

Region 5

FUNCTION NAME TELEPHONE

Maximum Achievable Control

Technology (MACT)

Bruce Varner 312-886-6793

Toxics Emissions Inventory Suzanne King 312-886-6054

Air Deposition Erin Newman 312-886-4587

Air Dispersion/ Deposition

Modeling

Randy Robinson

Phuong Nguyen

312-353-6713

312-886-6701

Monitoring Motria Caudill 312-886-0267

Community Assessments Jackie Nwia

Michele Palmer

312-886-6081

312-886-0387

Risk Assessment George Bollweg

Margaret Sieffert

Jaime Julian

312-353-5598

312-353-1151

312-886-9402

Mobile Sources Suzanne King 312-886-6054

Indoor Air Jack Barnette

Sheila Batka

312-886-6175

312-886-6053
April 2004 Page B-10

Region 6

FUNCTION NAME TELEPHONE

Maximum Achievable Control

Technology (MACT)

Jeff Robinson 214-665-6435

Toxics Emissions Inventory Herb Sherrow 214-665-7237

Air Deposition Phil Crocker 214-665-7373

Air Dispersion/ Deposition

Modeling

Quang Nguyen 214-665-7238

Monitoring Kuenja Chung 214-665-8345

Community Assessments Ruben Casso 214-665-6763

Risk Assessment Jeff Yurk 214-665-8309

Mobile Sources Sandra Rennie 214-665-7367

Indoor Air Mike Miller 214-665-7550
April 2004 Page B-11

Region 7

FUNCTION NAME TELEPHONE

Maximum Achievable Control

Technology (MACT)

Richard Tripp 913-551-7566

Toxics Emissions Inventory Michael Jay 913-551-7460

Air Deposition Michael Jay 913-551-7460

Air Dispersion/ Deposition

Modeling

Richard Daye 913-551-7619

Monitoring Michael Davis 913-551-7096

Community Assessments Marcus Rivas 913-551-7669

Risk Assessment James Hirtz 913-551-7472

Mobile Sources James Hirtz 913-551-7472

Indoor Air Robert Dye 913-551-7605
April 2004 Page B-12

Region 8

FUNCTION NAME TELEPHONE

Maximum Achievable Control

Technology (MACT)

Deldi Reyes 303-312-6055

Toxics Emissions Inventory Daniel Webster 303-312-6446

Air Deposition Anne-Marie Patrie 303-312-6524

Air Dispersion/ Deposition 

Modeling

Victoria Parker-Christensen 303-312-6441

Monitoring Michael Copeland 303-312-6010

Community Assessments Victoria Parker-Christensen

Anne-Marie Patrie

303-312-6441

303-312-6524

Risk Assessment Victoria Parker-Christensen

Anne-Marie Patrie

303-312-6441

303-312-6524

Mobile Sources Jeff Kimes 303-312-6445

Indoor Air Ron Schiller 303-312-6017
April 2004 Page B-13

Region 9

FUNCTION NAME TELEPHONE

Maximum Achievable Control

Technology (MACT)

Mae Wang 

John Brock

415-947-4124

415-947-3999

Toxics Emissions Inventory Larry Biland 415-947-4132

Air Deposition Pam Tsai

Barbara Toole-O’Neil

415-947-4196

415-972-3991

Air Dispersion/ Deposition

Modeling

Carol Bohnenkamp

Scott Bohning

415-947-4130

415-947-4127

Monitoring Catherine Brown 415-947-4137

Community Assessments Mike Bandrowski 415-947-4194

Risk Assessment Pam Tsai

Arnold Den

415-947-4196

415-947-4191

Indoor Air Barbara Spark 415-947-4189

Mobile Sources Sylvia Dugre

David Jesson

415-947-4149

415-947-4150
April 2004 Page B-14

Region 10

FUNCTION NAME TELEPHONE

Maximum Achievable Control

Technology (MACT)

 Lucita Valiere 206-553-8087

Toxics Emissions Inventory Madonna Narvaez 206-553-2117

Air Deposition Madonna Narvaez 206-553-2117

Air Dispersion/ Deposition 

Modeling

 Mahbubul Islam 206-553-6985

Monitoring Keith Rose 206-553-1949

Community Assessments Peter Murchie

Lisa McArthur

503-326-6554

206-553-1814

Risk Assessment Julie Wroble 206-553-1079

Mobile Sources Wayne Elson 206-553-1463

Indoor Air Ann Wawrukiewicz 206-553-2589
April 2004 Page B-15

4. Other Federal Agencies 

a. Agency for Toxics Substances and Disease Registry (ATSDR). The mission of the

Agency for Toxic Substances and Disease Registry (ATSDR), as an agency of the U.S.

Department of Health and Human Services, is to serve the public by using the best

science, taking responsive public health actions, and providing trusted health information

to prevent harmful exposures and disease related to toxic substances. ATSDR is directed

by congressional mandate to perform specific functions concerning the effect on public

health of hazardous substances in the environment. These functions include public health

assessments of waste sites, health consultations concerning specific hazardous

substances, health surveillance and registries, response to emergency releases of

hazardous substances, applied research in support of public health assessments,

information development and dissemination, and education and training concerning

hazardous substances. http://www.atsdr.cdc.gov/about.html

b. National Center for Environmental Health (NCEH). CDC’s National Center for

Environmental Health (NCEH) strives to promote health and quality of life by preventing

or controlling those diseases or deaths that result from interactions between people and

their environment. http://www.cdc.gov/nceh/

c. National Cancer Institute (NCI). The NCI is a component of the National Institutes of

Health (NIH), one of eight agencies that compose the Public Health Service (PHS) in the

Department of Health and Human Services (DHHS). The NCI, established under the

National Cancer Act of 1937, is the Federal Government’s principal agency for cancer

research and training. The National Cancer Act of 1971 broadened the scope and

responsibilities of the NCI and created the National Cancer Program. Over the years,

legislative amendments have maintained the NCI authorities and responsibilities and

added new information dissemination mandates as well as a requirement to assess the

incorporation of state-of-the-art cancer treatments into clinical practice. The National

Cancer Institute coordinates the National Cancer Program, which conducts and supports

research, training, health information dissemination, and other programs with respect to

the cause, diagnosis, prevention, and treatment of cancer, rehabilitation from cancer, and

the continuing care of cancer patients and the families of cancer patients. 

www.cancer.gov

d. National Library of Medicine (NLM). The National Library of Medicine (NLM), on

the campus of the National Institutes of Health in Bethesda, Maryland, is the world’s

largest medical library. The Library collects materials in all areas of biomedicine and

health care, as well as works on biomedical aspects of technology, the humanities, and

the physical, life, and social sciences. The collections stand at more than 6 million items-

-books, journals, technical reports, manuscripts, microfilms, photographs and images.

Housed within the Library is one of the world’s finest medical history collections of old

and rare medical works. The Library’s collection may be consulted in the reading room

or requested on interlibrary loan. NLM is a national resource for all U.S. health science

libraries through a National Network of Libraries of Medicine®. 

http://www.nlm.nih.gov/nlmhome.html
April 2004 Page B-16

e. National Institute of Environmental Health Sciences (NIEHS). Human health and

human disease result from three interactive elements: environmental factors, individual

susceptibility and age. The mission of the National Institute of Environmental Health

Sciences (NIEHS) is to reduce the burden of human illness and dysfunction from

environmental causes by understanding each of these elements and how they interrelate.

The NIEHS achieves its mission through multidisciplinary biomedical research programs,

prevention and intervention efforts, and communication strategies that encompass

training, education, technology transfer, and community outreach. 

http://www.niehs.nih.gov/external/welcome.htm
Appendix C Recommended Dose-Response Values

for HAPs

This appendix presents tabulated dose-response assessments that the Office of Air Quality

Planning and Standards (OAQPS) uses for risk assessments of hazardous air pollutants. A

description of the derivation of these values, along with any updates can be found at the

following website: http://www.epa.gov/ttn/atw/toxsource/summary.html.
CHEMICAL NAME CAS NO.1 

HAP

NO.2 EPA IARC mg/m3 SOURCE 1/(ug/m3) SOURCE mg/kg/d 

Acetaldehyde 75-07-0 1 B2 2B 0.009 IRIS 2.2E-06 IRISAcetamide 60-35-5 2 2B 2.0E-05 CALAcetonitrile 75-05-8 3 D 0.06 IRISAcetophenone 98-86-2 4 DAcrolein 107-02-8 6 3 0.00002 IRISAcrylamide 79-06-1 7 B2 2A 0.0007 P-CAL 1.3E-03 IRISAcrylic acid 79-10-7 8 0.001 IRISAcrylonitrile 107-13-1 9 B1 2A 0.002 IRIS 6.8E-05 IRISAllyl chloride 107-05-1 10 C 3 0.001 IRIS 6.0E-06 CALAniline 62-53-3 12 B2 3 0.001 IRIS 1.6E-06 CALAntimony compounds 7440-36-0 173Antimony pentoxide 1314-60-9 173Antimony potassium tartrate 304-61-0 173Antimony tetroxide 1332-81-6 173Antimony trioxide 1309-64-4 173 2B 0.0002 IRISArsenic compounds 7440-38-2 174 A 1 0.00003 CAL 4.3E-03 IRISArsine 7784-42-1 174 0.00005 IRISBenzene 71-43-2 15 A 1 0.03 IRIS 7.8E-06 IRISBenzidine 92-87-5 16 A 0.01 P-CAL 6.7E-02 IRISBenzotrichloride 98-07-7 17 B2 2B 3.7E-03 Conv. OralBenzyl chloride 100-44-7 18 B2 2B 4.9E-05 CALBeryllium compounds 7440-41-7 175 B1 1 0.00002 IRIS 2.4E-03 IRISBiphenyl 92-52-4 19 DBis(2-ethylhexyl)phthalate 117-81-7 20 B2 2B 0.01 CAL 2.4E-06 CALBis(chloromethyl)ether 542-88-1 21 A 1 6.2E-02 IRISBromoform 75-25-2 22 B2 3 1.1E-06 IRIS1,3-Butadiene 106-99-0 23 A 2A 0.002 IRIS 3.0E-05 IRISCadmium compounds 7440-43-9 176 B1 1 0.00002 CAL 1.8E-03 IRIS 0.0005 Captan 133-06-2 26 B2 3 1.0E-06 Conv. OralCarbaryl 63-25-2 27Carbon disulfide 75-15-0 28 0.7 IRISCarbon tetrachloride 56-23-5 29 B2 2B 0.04 CAL 1.5E-05 IRISChloramben 133-90-4 32Chlordane 57-74-9 33 B2 2B 0.0007 IRIS 1.0E-04 IRIS 0.0005 Chlorine 7782-50-5 34 0.0002 CALChloroacetic acid 79-11-8 352-Chloroacetophenone 532-27-4 36 0.00003 IRISChlorobenzene 108-90-7 37 D 1 CALChlorobenzilate 510-15-6 38 B2 7.8E-05 HEASTChloroform 67-66-3 39 B2 2B 0.098 ATSDRChloroprene 126-99-8 41 0.007 HEASTChromium (III) compounds 16065-83-1 177 DChromium (VI) compounds 18540-29-9 177 A 1 0.0001 IRIS 1.2E-02 IRIS

Table 1. Prioritized Dose-Response Values (10/28/03) WOE3 for Cancer CHRONIC INHALATION 

NONCANCER CANCER NONCA

April 2004 
CHEMICAL NAME CAS NO.1 

HAP

NO.2 EPA IARC mg/m3 SOURCE 1/(ug/m3) SOURCE mg/kg/d 

Table 1. Prioritized Dose-Response Values (10/28/03) WOE3 for Cancer CHRONIC INHALATION 

NONCANCER CANCER NONCA

Chromium (VI) trioxide, chromic acid mist 11115-74-5 177 A 1 0.000008 IRISCobalt compounds 7440-48-4 178 0.0001 ATSDRCoke Oven Emissions 8007-45-2 179 A 6.2E-04 IRISm-Cresol 108-39-4 44 Co-Cresol 95-48-7 43 Cp-Cresol 106-44-5 45 CCresols (mixed) 1319-77-3 42 C 0.6 CALCumene 98-82-8 46 D 0.4 IRISCyanazine 21725-46-2 180 C 2.4E-04 Conv. OralCyanide compounds 57-12-5 180 DAcetone cyanohydrin 75-86-5 180 0.01 HEASTCalcium cyanide 592-01-8 180Copper cyanide 544-92-3 180Cyanogen 460-19-5 180Cyanogen bromide 506-68-3 180Cyanogen chloride 506-77-4 180Ethylene cyanohydrin 109-78-4 180Hydrogen cyanide 74-90-8 180 0.003 IRISPotassium cyanide 151-50-8 180Potassium silver cyanide 506-61-6 180Silver cyanide 506-64-9 180Sodium cyanide 143-33-9 180Thiocyanic acid, 2-(benzothiazolylthio) methyl est 21564-17-0 180

Zinc cyanide 557-21-1 1802,4-D, salts and esters 94-75-7 47DDE 72-55-9 48 B2 9.7E-05 Conv. Oral 

1,2-Dibromo-3-chloropropane 96-12-8 51 B2 0.0002 IRIS 2.0E-03 CALDibutylphthalate 84-74-2 52 Dp-Dichlorobenzene 106-46-7 53 C 2B 0.8 IRIS 1.1E-05 CAL3,3'-Dichlorobenzidine 91-94-1 54 B2 2B 3.4E-04 CALDichloroethyl ether 111-44-4 55 B2 3.3E-04 IRIS1,3-dichloropropene 542-75-6 56 B2 2B 0.02 IRIS 4.0E-06 IRISDichlorvos 62-73-7 57 B2 2B 0.0005 IRIS 8.3E-05 Conv. OralDiesel engine emissions DIESEL EMIS. 190 B1 0.005 IRISDiethanolamine 111-42-2 58 0.003 CAL3,3'-Dimethoxybenzidine 119-90-4 61 B2 2B 4.0E-06 Conv. Oralp-Dimethylaminoazobenzene 60-11-7 62 2B 1.3E-03 CAL3,3'-Dimethylbenzidine 119-93-7 63 B2 2.6E-03 Conv. OralDimethyl formamide 68-12-2 65 2B 0.03 IRISN,N-dimethylaniline 121-69-7 59 31,1-Dimethylhydrazine 57-14-7 66 B2 2B2,4-dinitrophenol 51-28-5 702,4-Dinitrotoluene 121-14-2 71 B2 2B 0.007 P-CAL 8.9E-05 CAL

April 2004 
CHEMICAL NAME CAS NO.1 

HAP

NO.2 EPA IARC mg/m3 SOURCE 1/(ug/m3) SOURCE mg/kg/d 

Table 1. Prioritized Dose-Response Values (10/28/03) WOE3 for Cancer CHRONIC INHALATION 

NONCANCER CANCER NONCA

2,4/2,6-Dinitrotoluene (mixture) 25321-14-6 71 B2 2B 1.9E-04 Conv. Oral1,4-Dioxane 123-91-1 72 B2 2B 3 CAL 3.1E-06 Conv. Oral1,2-Diphenylhydrazine 122-66-7 73 B2 2.2E-04 IRISEpichlorohydrin 106-89-8 74 B2 2A 0.001 IRIS 1.2E-06 IRIS1,2-Epoxybutane 106-88-7 75 0.02 IRISEthyl acrylate 140-88-5 76 B2 2B 1.4E-05 Conv. OralEthyl benzene 100-41-4 77 D 1 IRISEthyl carbamate 51-79-6 78 2B 2.9E-04 CALEthyl chloride 75-00-3 79 10 IRISEthylene dibromide 106-93-4 80 B2 2A 0.0008 CAL 2.2E-04 IRISEthylene dichloride 107-06-2 81 B2 2B 2.4 ATSDR 2.6E-05 IRISEthylene glycol 107-21-1 82 0.4 CALEthylene oxide 75-21-8 84 B1 1 0.03 CAL 8.8E-05 CALEthylene thiourea 96-45-7 85 B2 2B 0.003 P-CAL 1.3E-05 CALEthylidene dichloride 75-34-3 86 C 0.5 HEAST 1.6E-06 CALFormaldehyde 50-00-0 87 B1 2A 0.0098 ATSDR 5.5E-09 EPA OAQPSDiethylene glycol monobutyl ether 112-34-5 181 0.02 HEASTDiethylene glycol monoethyl ether 111-90-0 181

Ethylene glycol butyl ether 111-76-2 181 C 13 IRIS

Ethylene glycol ethyl ether 110-80-5 181 0.2 IRISEthylene glycol ethyl ether acetate 111-15-9 181 0.3 CALEthylene glycol methyl ether 109-86-4 181 0.02 IRISEthylene glycol methyl ether acetate 110-49-6 181 0.09 CALHeptachlor 76-44-8 88 B2 2B 1.3E-03 IRIS 0.0005 Hexachlorobenzene 118-74-1 89 B2 2B 0.003 P-CAL 4.6E-04 IRIS 0.0008 Hexachlorobutadiene 87-68-3 90 C 3 0.09 P-CAL 2.2E-05 IRISHexachlorocyclopentadiene 77-47-4 91 E 0.0002 IRISHexachlorodibenzo-p-dioxin, mixture 19408-74-3 187 B2 1.3E+00 IRIS Hexachloroethane 67-72-1 92 C 3 0.08 P-CAL 4.0E-06 IRISHexamethylene-1,6-diisocyanate 822-06-0 93 0.00001 IRISn-Hexane 110-54-3 95 0.2 IRISHydrazine 302-01-2 96 B2 2B 0.0002 CAL 4.9E-03 IRISHydrochloric acid 7647-01-0 97 0.02 IRISHydrofluoric acid 7664-39-3 98 0.03 CALHydroquinone 123-31-9 99Isophorone 78-59-1 100 C 2 CAL 2.7E-07 Conv. OralLead compounds 7439-92-1 182 B2 2B 0.0015 EPA OAQPSTetraethyl lead 78-00-2 182 0.0000001 Lindane (gamma-HCH) 58-89-9 101 2B 0.0003 P-CAL 3.1E-04 CAL 0.0003 alpha-Hexachlorocyclohexane (a-HCH) 319-84-6 101 B2 2B 0.02 P-CAL 1.8E-03 IRIS 0.008 beta-Hexachlorocyclohexane (b-HCH) 319-85-7 101 C 2B 0.002 P-CAL 5.3E-04 IRIS technical Hexachlorocyclohexane (HCH) 608-73-1 101 B2 2B 5.1E-04 IRIS Maleic anhydride 108-31-6 102 0.0007 CAL

April 2004 
CHEMICAL NAME CAS NO.1 

HAP

NO.2 EPA IARC mg/m3 SOURCE 1/(ug/m3) SOURCE mg/kg/d 

Table 1. Prioritized Dose-Response Values (10/28/03) WOE3 for Cancer CHRONIC INHALATION 

NONCANCER CANCER NONCA

Manganese compounds 7439-96-5 183 D 0.00005 IRISMercuric chloride 7487-94-7 184 C 0.00009 CAL 0.0003 Mercury (elemental) 7439-97-6 184 D 0.0003 IRISMethyl mercury 22967-92-6 184 C 0.0001 Phenylmercuric acetate 62-38-4 184 0.00008 Methanol 67-56-1 103 4 CALMethoxychlor 72-43-5 104 D 3 0.005 Methyl bromide 74-83-9 105 D 0.005 IRISMethyl chloride 74-87-3 106 D 0.09 IRISMethyl ethyl ketone 78-93-3 108 5 IRISMethyl isobutyl ketone 108-10-1 111 3 IRISMethyl isocyanate 624-83-9 112 0.001 CALMethyl methacrylate 80-62-6 113 E 0.7 IRISMethyl tert-butyl ether 1634-04-4 114 3 IRIS4,4'-Methylene bis(2-chloroaniline) 101-14-4 115 B2 2A 4.3E-04 CALMethylene chloride 75-09-2 116 B2 2B 1 ATSDR 4.7E-07 IRISMethylene diphenyl diisocyanate 101-68-8 117 D 0.0006 IRIS4,4'-Methylenedianiline 101-77-9 118 2B 0.02 CAL 4.6E-04 CALNaphthalene 91-20-3 119 C 0.003 IRISNickel compounds 7440-02-0 186 A 2B 0.0002 ATSDRNickel oxide 1313-99-1 186 0.0001 CALNickel refinery dust NI_DUST 186 A 2.4E-04 IRISNickel subsulfide 12035-72-2 186 A 4.8E-04 IRISNitrobenzene 98-95-3 120 D 2B 0.03 P-CAL2-Nitropropane 79-46-9 123 B2 2B 0.02 IRIS 5.6E-06 EPA OAQPSNitrosodimethylamine 62-75-9 125 B2 2A 1.4E-02 IRISN-Nitrosomorpholine 59-89-2 126 2B 1.9E-03 CALParathion 56-38-2 127 C 3Polychlorinated biphenyls 1336-36-3 136 B2 2A 1.0E-04 IRIS Aroclor 1016 12674-11-2 136 0.00007 Aroclor 1254 11097-69-1 136 0.00002 Pentachloronitrobenzene 82-68-8 128 C 3 7.4E-05 Conv. OralPentachlorophenol 87-86-5 129 B2 2B 0.1 P-CAL 5.1E-06 CALPhenol 108-95-2 130 D 3 0.2 CALp-Phenylenediamine 106-50-3 131Phosgene 75-44-5 132 0.0003 P-CALPhosphine 7803-51-2 133 D 0.0003 IRISPhosphorus, white 7723-14-0 134 D 0.00007 P-CALPhthalic anhydride 85-44-9 135 0.02 CALPolybrominated Diphenyl Ethers PBDE 187 0.007 Acenaphthene 83-32-9 187 D 0.06 Acenaphthylene 206-96-8 187 DAnthracene 120-12-7 187 D 3 0.3 

April 2004 
CHEMICAL NAME CAS NO.1 

HAP

NO.2 EPA IARC mg/m3 SOURCE 1/(ug/m3) SOURCE mg/kg/d 

Table 1. Prioritized Dose-Response Values (10/28/03) WOE3 for Cancer CHRONIC INHALATION 

NONCANCER CANCER NONCA

Benzo(a)anthracene 56-55-3 187 B2 2A 1.1E-04 CAL Benzo(b)fluoranthene 205-99-2 187 B2 2B 1.1E-04 CAL Benzo[j]fluoranthene 205-82-3 187 2B 1.1E-04 CAL Benzo(k)fluoranthene 207-08-9 187 B2 2B 1.1E-04 CAL Benzo(g,h,i)perylene 191-24-2 187 D 3Benzo(a)pyrene 50-32-8 187 B2 2A 1.1E-03 CAL Benzo(e)pyrene 192-97-2 187 3Carbazole 86-74-8 187 B2 3 5.7E-06 Conv. Oral beta-Chloronaphthalene 91-58-7 187 0.08 Chrysene 218-01-9 187 B2 3 1.1E-05 CAL Dibenz[a,h]acridine 226-36-8 187 2B 1.1E-04 CAL Dibenz[a,j]acridine 224-42-0 187 2B 1.1E-04 CAL Dibenz(a,h)anthracene 53-70-3 187 B2 2A 1.2E-03 CAL 7H-Dibenzo[c,g]carbazole 194-59-2 187 2B 1.1E-03 CAL Dibenzo[a,e]pyrene 192-65-4 187 2B 1.1E-03 CAL Dibenzo[a,h]pyrene 189-64-0 187 2B 1.1E-02 CAL Dibenzo[a,i]pyrene 189-55-9 187 2B 1.1E-02 CAL Dibenzo[a,l]pyrene 191-30-0 187 2B 1.1E-02 CAL 7,12-Dimethylbenz(a)anthracene 57-97-6 187 7.1E-02 CAL 1,6-Dinitropyrene 42397-64-8 187 2B 1.1E-02 CAL 1,8-Dinitropyrene 42397-65-9 187 2B 1.1E-03 CAL Fluoranthene 206-44-0 187 D 3 0.04 Fluorene 86-73-7 187 D 3 0.04 Indeno(1,2,3-cd)pyrene 193-39-5 187 B2 2B 1.1E-04 CAL 3-Methylcholanthrene 56-49-5 187 6.3E-03 CAL 5-Methylchrysene 3697-24-3 187 2B 1.1E-03 CAL 1-Methylnaphthalene 90-12-0 187 0.07 5-Nitroacenaphthene 602-87-9 187 2B 3.7E-05 CAL 6-Nitrochrysene 7496-02-8 187 2B 1.1E-02 CAL 2-Nitrofluorene 607-57-8 187 2B 1.1E-05 CAL 1-Nitropyrene 5522-43-0 187 2B 1.1E-04 CAL 4-Nitropyrene 57835-92-4 187 2B 1.1E-04 CAL Phenanthrene 85-01-8 187 DPyrene 129-00-0 187 D 0.03 1,3-Propane sultone 1120-71-4 137 2B 6.9E-04 CALPropoxur 114-26-1 140 B2Propylene dichloride 78-87-5 141 B2 0.004 IRIS 1.9E-05 Conv. OralPropylene oxide 75-56-9 142 B2 2B 0.03 IRIS 3.7E-06 IRISQuinoline 91-22-5 144 B2Selenium compounds 7782-49-2 189 D 0.02 CALHydrogen selenide 7783-07-5 189 0.00008 CALSelenious acid 7783-00-8 189 DSelenourea 630-10-4 189

April 2004 
CHEMICAL NAME CAS NO.1 

HAP

NO.2 EPA IARC mg/m3 SOURCE 1/(ug/m3) SOURCE mg/kg/d 

Table 1. Prioritized Dose-Response Values (10/28/03) WOE3 for Cancer CHRONIC INHALATION 

NONCANCER CANCER NONCA

Styrene 100-42-5 146 2B 1 IRISStyrene oxide 96-09-3 147 2A 0.006 P-CAL2,3,7,8-Tetrachlorodibenzo-p-dioxin 1746-01-6 148 B2 4E-08 CAL 3.3E+01 EPA ORD 1E-09 1,1,2,2-Tetrachloroethane 79-34-5 149 C 3 5.8E-05 IRISTetrachloroethene 127-18-4 150 B2-C 2A 0.27 ATSDR 5.9E-06 CALTitanium tetrachloride 7550-45-0 151 0.0001 ATSDRToluene 108-88-3 152 D 3 0.4 IRIS2,4-Toluene diamine 95-80-7 153 B2 1.1E-03 CAL2,4/2,6-Toluene diisocyanate mixture (TDI) 26471-62-5 154 2B 0.00007 IRIS 1.1E-05 CALo-Toluidine 95-53-4 155 B2 2B 5.1E-05 CALToxaphene 8001-35-2 156 B2 2B 3.2E-04 IRIS 1,2,4-Trichlorobenzene 120-82-1 157 D 0.2 HEAST1,1,2-Trichloroethane 79-00-5 158 C 3 0.4 P-CAL 1.6E-05 IRIS1,1,1-Trichloroethane 71-55-6 107 D 1 CALTrichloroethylene 79-01-6 159 B2-C 2A 0.6 CAL 2.0E-06 CAL2,4,5-Trichlorophenol 95-95-4 1602,4,6-Trichlorophenol 88-06-2 161 B2 3.1E-06 IRISTriethylamine 121-44-8 162 0.007 IRISTrifluralin 1582-09-8 163 C 3 2.2E-06 Conv. Oral 0.0075 Uranium compounds 7440-61-1 188 0.0003 ATSDRUranium, soluble salts URANSOLS 188Vinyl acetate 108-05-4 165 2B 0.2 IRISVinyl bromide 593-60-2 166 B2 2A 0.003 IRIS 3.2E-05 HEASTVinyl chloride 75-01-4 167 A 1 0.1 IRIS 8.8E-06 IRISVinylidene chloride 75-35-4 168 C 0.2 IRISm-Xylene 108-38-3 171o-Xylene 95-47-6 170Xylenes (mixed) 1330-20-7 169 0.1 IRIS1Chemical Abstracts Services number for the compound.2Position of the compound on the HAP list in the Clean Air Act (112[b][2])3Weight-of-evidence. See http://www.epa/iris/carcino.htm, http://193.51.164.11/monoeval/grlist.html.

April 2004 
ERPG-1 ERPG-2 ERPG-3 

CHEMICAL NAME CAS NO. HAP NO. mg/m3 mg/m3 mg/m3 

Acetaldehyde 75-07-0 1 18 360 1800 Acetonitrile 75-05-8 3 Acrolein 107-02-8 6 0.069 p 0.23 p 3.2 p 0.23 1.1 6.9 

Acrylamide 79-06-1 7 Acrylic acid 79-10-7 8 2.9 i 140 i 530 i 5.9 150 2200 

Acrylonitrile 107-13-1 9 22 77 170 Allyl chloride 107-05-1 10 9.4 130 940 Aniline 62-53-3 12 30 f 46 f 57 f 

Anisidine 90-04-0 13 Antimony compounds 7440-36-0 173 Arsenic compounds 7440-38-2 174 Arsine 7784-42-1 174 0.54 f 1.6 f 1.6 4.8 

Benzene 71-43-2 15 2600 p 13000 p 160 480 3200 

Benzyl chloride 100-44-7 18 5.2 52 130 Beryllium compounds 7440-41-7 175 0.025 0.1 Bis(chloromethyl)ether 542-88-1 21 0.47 2.4Bromoform 75-25-2 22 1,3-Butadiene 106-99-0 23 22 440 11000 Cadmium compounds 7440-43-9 176 Carbaryl 63-25-2 27 Carbon disulfide 75-15-0 28 12 p 500 p 1500 p 3.1 160 1600 

Carbon tetrachloride 56-23-5 29 75 i 350 i 1100 i 130 630 4700 

Chlordane 57-74-9 33 Chlorine 7782-50-5 34 1.5 i 5.8 i 58 i 2.9 8.7 58 

Chloroacetic acid 79-11-8 35 26 p

Chlorobenzene 108-90-7 37 Chloroform 67-66-3 39 430 p 8300 p 240 24000 

Chloromethyl methyl ether 107-30-2 40 0.2 i 3.1 i 3.3 33

Chloroprene 126-99-8 41 Chromium (VI) compounds 18540-29-9 177 Chromium (VI) trioxide, chromic acid mist 11115-74-5 177 Cobalt compounds 7440-48-4 178 m-Cresol 108-39-4 44 o-Cresol 95-48-7 43 p-Cresol 106-44-5 45 Cresols (mixed) 1319-77-3 42 Cumene 98-82-8 46 Cyanide compounds 57-12-5 180 Acetone cyanohydrin 75-86-5 180 2.9 p 19 p 52 p

Cyanogen chloride 506-77-4 180 1 10Hydrogen cyanide 74-90-8 180 2.2 i 7.8 f 17 f 11 28 

2,4-D, salts and esters 94-75-7 47 

mg/m3 mg/m3 mg/m3

Table 2. Acute Dose-Response Values (10/22/03) AEGL-1 AEGL-2 AEGL-3

April 2004 
ERPG-1 ERPG-2 ERPG-3 

CHEMICAL NAME CAS NO. HAP NO. mg/m3 mg/m3 mg/m3 

mg/m3 mg/m3 mg/m3

Table 2. Acute Dose-Response Values (10/22/03) AEGL-1 AEGL-2 AEGL-3

Dibutylphthalate 84-74-2 52 p-Dichlorobenzene 106-46-7 53 Dichloroethyl ether 111-44-4 55 Dichlorvos 62-73-7 57 Dimethyl formamide 68-12-2 65 270 p 540 p 6 300 600 

Dimethyl phthalate 131-11-3 67 Dimethyl sulfate 77-78-1 68 N,N-dimethylaniline 121-69-7 59 1,1-Dimethylhydrazine 57-14-7 66 7.4 f 27 f 

4,6-Dinitro-o-cresol 534-52-1 69 2,4-Dinitrotoluene 121-14-2 71 1,4-Dioxane 123-91-1 72 61 p 1200 p 2700 p 

Epichlorohydrin 106-89-8 74 19 p 91 p 270 p 7.6 76 380 

Ethyl acrylate 140-88-5 76 0.041 120 1200 Ethyl benzene 100-41-4 77 Ethyl chloride 75-00-3 79 Ethylene dibromide 106-93-4 80 Ethylene dichloride 107-06-2 81 200 810 810 Ethylene glycol 107-21-1 82 Ethylene imine (aziridine) 151-56-4 83 8.1 i 17 i

Ethylene oxide 75-21-8 84 81 i 360 i 90 900 

Ethylidene dichloride 75-34-3 86 Formaldehyde 50-00-0 87 0.49 p 17 p 61 p 1.2 12 31 

Ethylene glycol butyl ether 111-76-2 181 Ethylene glycol ethyl ether 110-80-5 181 Ethylene glycol ethyl ether acetate 111-15-9 181 Ethylene glycol methyl ether 109-86-4 181 Heptachlor 76-44-8 88 Hexachlorobutadiene 87-68-3 90 32 110 320Hexachloroethane 67-72-1 92 n-Hexane 110-54-3 95 Hydrazine 302-01-2 96 0.13 i 17 i 46 i 0.65 6.5 39 

Hydrochloric acid 7647-01-0 97 2.7 i 33 i 150 i 4.5 30 220 

Hydrofluoric acid 7664-39-3 98 0.82 i 20 i 36 i 1.6 16 41 Hydroquinone 123-31-9 99 Lead compounds 7439-92-1 182 Tetraethyl lead 78-00-2 182 Tetramethyl lead 75-74-1 182 Lindane (gamma-HCH) 58-89-9 101 Maleic anhydride 108-31-6 102 Manganese compounds 7439-96-5 183 Mercury (elemental) 7439-97-6 184 1.6 16 

April 2004 
ERPG-1 ERPG-2 ERPG-3 

CHEMICAL NAME CAS NO. HAP NO. mg/m3 mg/m3 mg/m3 

mg/m3 mg/m3 mg/m3

Table 2. Acute Dose-Response Values (10/22/03) AEGL-1 AEGL-2 AEGL-3

Mercury compounds HG_CMPDS 184 Methyl mercury 22967-92-6 184 Methanol 67-56-1 103 690 i 2700 i 10000 i 260 1300 6500 

Methoxychlor 72-43-5 104 Methyl bromide 74-83-9 105 190 780 Methyl chloride 74-87-3 106 830 2100 Methyl ethyl ketone 78-93-3 108 290 p 5000 p 12000 p 

Methyl hydrazine 60-34-4 109 3.6 f 11 f 

Methyl iodide 74-88-4 110 150 290 730 Methyl isocyanate 624-83-9 112 0.16 i 0.47 i 0.058 1.2 12 

Methyl methacrylate 80-62-6 113 Methyl tert-butyl ether 1634-04-4 114 Methylene chloride 75-09-2 116 690 2600 14000 Methylene diphenyl diisocyanate 101-68-8 117 0.2 2 25 Naphthalene 91-20-3 119 Nickel carbonyl 13463-39-3 186 0.25 i 1.1 i 

Nickel compounds 7440-02-0 186 Nitrobenzene 98-95-3 120 2-Nitropropane 79-46-9 123 Parathion 56-38-2 127 Pentachlorophenol 87-86-5 129 Phenol 108-95-2 130 17 i 58 i 180 i 38 190 770 

Phosgene 75-44-5 132 1.2 f 3 f 0.81 4 

Phosphine 7803-51-2 133 2.8 i 5 i 0.7 7

Phosphorus, white 7723-14-0 134 Phthalic anhydride 85-44-9 135 Propylene dichloride 78-87-5 141 Propylene oxide 75-56-9 142 140 i 690 i 1400 i 120 590 1800 

1,2-Propyleneimine 75-55-8 143 28 i 54 i

Quinone 106-51-4 145 Selenium compounds 7782-49-2 189 Hydrogen selenide 7783-07-5 189 2.4 p 7.3 p 0.66 6.6 

Styrene 100-42-5 146 210 1100 4300 1,1,2,2-Tetrachloroethane 79-34-5 149 Tetrachloroethene 127-18-4 150 240 i 1600 i 8100 i 680 1400 6800 

Titanium tetrachloride 7550-45-0 151 0.54 p 7.8 p 44 p 5 20 100

Toluene 108-88-3 152 750 i 1900 i 11000 i 190 1100 3800 

2,4-Toluene diisocyanate 584-84-9 154 0.14 i 0.59 i 3.6 i 0.071 

o-Toluidine 95-53-4 155 1,1,2-Trichloroethane 79-00-5 158 1,1,1-Trichloroethane 71-55-6 107 1300 i 3300 i 21000 i 1900 3800 19000 

Trichloroethylene 79-01-6 159 700 p 2400 p 20000 p 540 2700 27000 

April 2004 
ERPG-1 ERPG-2 ERPG-3 

CHEMICAL NAME CAS NO. HAP NO. mg/m3 mg/m3 mg/m3 

mg/m3 mg/m3 mg/m3

Table 2. Acute Dose-Response Values (10/22/03) AEGL-1 AEGL-2 AEGL-3

Triethylamine 121-44-8 162 Uranium compounds 7440-61-1 188 Uranium hexafluoride 7783-81-5 188 52 i 140 i 520 i 5 15 30

Vinyl acetate 108-05-4 165 18 260 1800Vinyl chloride 75-01-4 167 640 p 3100 p 12000 p 

m-Xylene 108-38-3 171 o-Xylene 95-47-6 170 p-Xylene 106-42-3 172 Xylenes (mixed) 1330-20-7 169 560 p 1900 p 4000 p 

AEGLs: f = final, I = interim, p = proposed

April 2004 
Appendix D Methodology for Identifying PB-HAP

Compounds

April 2004 Page D-1

This Appendix provides and justifies a list of hazardous air pollutants that have sufficient

persistence and bioaccumulation potential to make them candidates for multipathway risk

assessments. The list was selected in two stages. 

The first stage was to determine which HAPs are already listed as persistent, bioaccumulative,

and toxic (PBT) substances by the following EPA programs:

1. Priority PBT Profiles (Pollution Prevention program): http://www.epa.gov/pbt/cheminfo.htm.

2. Great Waters Pollutants of Concern:

http://www.epa.gov/oar/oaqps/gr8water/3rdrpt/execsum.html.

3. Toxics Release Inventory: http://www.epa.gov/tri/chemical/pbt_chem_list.htm.

All substances that are both HAPs pursuant to the CAA and listed by at least one of these

programs are shown in Exhibit 1.

The second stage was to determine if, based on their toxicity and bioaccumulation potential, any

additional substances should be assessed for multipathway risk by the air toxics program. This

determination was made by calculating two indexes for all HAPs for which data could be

obtained. One index (intended to estimate relative carcinogenic potential by oral exposure) was

the product of the oral carcinogenic potency slope and the bioconcentration factor (obtained

from the EPA PBT Profiler, http://www.pbtprofiler.net/). The other index (intended to estimate

relative noncarcinogenic hazard by oral exposure) was the ratio of the same bioconcentration

factor to the oral reference dose. The cancer and noncancer indexes were normalized to a scale

of 1 and combined by averaging (with chemicals with no data not averaged, rather than averaged

as zero).

The HAPs were then ranked in descending order of the combined index, and the substances that

comprised 99.9999% of the total of all substances were selected as potential candidates for

multipathway risk assessment. Results of the ranking exercise are shown in Exhibit 1. 

Of the 26 substances that comprised 99.9999% of the aggregate index for all HAPs, 19 are

classified as polycyclic organic matter under the Clean Air Act. These were combined into a

single category in the table. Metals could not be ranked because the PBT Profiler does not

contain data for inorganic pollutants, but were included in the table because of their presence on

the other lists. Three other substances shown as “NA” fell outside the 99.9999% aggregate limit.

In summary, no substance not already on at least one existing list emerged in this analysis as a

significant potential PBT substance. Therefore, based on our current estimates of toxicity and

bioaccumulation potential, the 14 substances in the table represent a conservative list for

multipathway risk assessments in the air toxics program.
April 2004 Page D-2

Exhibit 1. Identity and Ranking of Potential PB-HAP Compounds

PB-HAP Compound OAQPS

Rank

Pollution

Prevention

Priority

PBTs

Great Waters

Pollutants of

Concern

TRI PBT

Chemicals

Cadmium compounds NA(1) X

Chlordane 7 X X X

Chlorinated dibenzodioxins and furans 1 X(2) X X(3)

DDE 8 X X

Heptachlor 4 X

Hexachlorobenzene 6 X X X

Hexachlorocyclohexane (all isomers) NA(4) X

Lead compounds NA(1) X(5) X X

Mercury compounds NA(1) XXX

Methoxychlor NA(4) X

Polychlorinated biphenyls 3 X X X

Polycyclic organic matter 2(6) X(7) X X(8)

Toxaphene 5 X X X

Trifluralin NA(4) X

(1) Not ranked because the PBT Profiler lacks data for inorganic compounds

(2) “Dioxins and furans” (denotes the phraseology of the source list)

(3) “Dioxin and dioxin-like compounds”

(4) Did not fall within 99.9999% of cumulative index

(5) Alkyl lead

(6) 19 POM compounds that fell within the top 26 substances were assigned the rank of

7,12-dimethylbenz(a)anthracene, the highest-ranked compound

(7) Benzo[a]pyrene

(8) “Polycyclic aromatic compounds” and benzo[g,h,i]perylene 
Appendix E Overview of Air Toxics Emission

Sources

This appendix provides general information on the types of air toxics commonly associated with

various types of sources. The table begins with the regulated major source categories and is

followed by mobile sources, indoor sources, and miscellaneous sources. This table is not meant

to be a comprehensive listing of all chemicals that may be emitted from a given source or group

of sources in a particular location.

April 2004 Page E-1

Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

Commercial / Industrial Sources

Halogenated Solvent

Cleaners (1614)

methylene chloride;

perchloroethylene;

trichloroethylene; 

1,1,1-trichloroethane;

carbon tetrachloride;

chloroform(c)

SIC: 33, 34, 36, 37

NAICS: 332, 333,

334, 335, 336, 447

MACT/GACT, see 40 CFR Part

63 Subpart T

U.S. EPA. 1995. Profile of the Iron and

Steel Industry. Office of Compliance Sector

Notebook Project, Washington, D.C.,

September 1995. EPA/310-R-95-005. 

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/iron

.html 

Acetal Resins

Production (1301)

SIC: 2869

NAICS: 325199

MACT, see 40 CFR Part 63 YY

(General MACT)

U.S. EPA. 1997. Profile of the Plastic

Resins and Man-made Fibers Industry. 

Office of Compliance Sector Notebook

Project, Washington, D.C., September 1997. 

EPA/310-R-97-008. Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/plas

tic.html 

Acrylic/Modacrylic

Fibers Production

(1001)

SIC: 2869

NAICS: 325199 

MACT, see 40 CFR Part 63 YY U.S. EPA. 1997. Profile of the Plastic

Resins and Man-made Fibers Industry. 

Office of Compliance Sector Notebook

Project, Washington, D.C., September 1997. 

EPA/310-R-97-008. Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/plas

tic.html 
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-2

AcrylonitrileButadiene-Styrene

Production (1302)

styrene; acrylonitrile;

butadiene; ethylene

glycol; methanol;

acetaldehyde;

dioxane

SIC: 2821, 2822

NAICS: 325211,

325212

MACT, see 40 CFR Part 63 JJJ U.S. EPA. 2001. Polymers and Resins IV

Inspection Tool. Adopt-a-MACT

Compliance Tool, Washington, D.C.,

September 2001. Available at:

http://www.epa.gov/ttn/atw/pr4/privinspect.h

tml

USEPA. 1997. Profile of the Plastic Resins

and Man-made Fibers Industry. Office of

Compliance Sector Notebook Project,

Washington, D.C., September 1997. 

EPA/310-R-97-008. Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/plas

tic.html 

Aerospace Industries

(0701)

chromium; cadmium;

methylene; chloride;

toluene; xylene;

methyl ethyl ketone;

ethylene glycol;

glycol ethers

SIC: 3720, 3721,

3724, 3728, 3760,

3761, 3764, 3769

NAICS: 336411,

336412, 336413,

336414, 336419,

481111, 481112

MACT, see 40 CFR Part 63

Subpart GG

U.S. EPA. 1998. Profile of the Aerospace

Industry. Office of Compliance Sector

Notebook Project, Washington, D.C.,

November 1998. EPA/310-R-98-001. 

Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/aero

space.html

Amino/Phenolic Resins

Production (1347)

formaldehyde,

methanol, phenol,

xylene, toluene

SIC: 2821

NAICS: 325211

MACT, see 40 CFR Part 63

Subpart OOO

U.S. EPA. 1997. Profile of the Plastic

Resins and Man-made Fibers Industry.

Office of Compliance Sector Notebook

Project, Washington, D.C., September 1997. 

EPA/310-R-97-006. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/plas

tic.html 

U.S. EPA. 1998. Hazardous Air Pollutant

Emissions from the Manufacture of Amino

and Phenolic Resins: Basis and Purpose

Document for Proposed Standards. 

Emission Standards Division, Washington,

D.C., May 1998. Available at: 

http://www.epa.gov/ttn/atw/amino/p_r3bpd.

wpd
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-3

Ammonium Sulfate -

Caprolactam ByProduct Plants (1401)

toluene; methanol;

xylene; methyl ethyl

ketone; ethyl

benzene; methyl

isobutyl ketone;

hydrogen chloride;

vinyl acetate

NAICS: 3251, 3252,

3253, 3254, 3255,

3256, 3259

MACT, see 40 CFR Part 63

Subpart FFFF

U.S. EPA. 2002. Profile of the Organic

Chemical Industry. Office of Compliance

Sector Notebook Project, Washington, D.C.,

November 2002. EPA/310-R-02-001. 

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/org

anic.html

Asphalt Roofing and

Processing (0418)

formaldehyde;

hexane; hydrogen

chloride; phenol;

polycyclic organic

matter; toluene

SIC: 2911, 2952

NAICS: 32411,

324122

MACT, see 40 CFR Part 63

Subpart LLLLL

U.S. EPA. 1995. Profile of the Stone, Clay,

Glass and Concrete Industry. Office of

Compliance Sector Notebook Project,

Washington, D.C., September 1995. 

EPA/310-R-95-017. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/ston

e.html
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-4

Asphalt/Coal Tar

Application - Metal

Pipes (0402)

xylenes; toluene;

methyl ethyl ketone;

phenol;

cresols/cresylic acid;

glycol ethers

(including ethylene

glycol monobutyl

ether); styrene;

methyl isobutyl

ketone; ethyl

benzene

NAICS: 335312,

336111, 336211,

336312, 33632,

33633, 33634, 33637,

336399, 331316,

331524, 332321,

332323, 33312,

333611, 333618,

332312, 332722,

332813, 332991,

332999, 334119,

336413, 339999,

33612, 336211,

331319, 331422,

335929, 332311,

33242, 81131,

322214, 326199,

331513, 332439,

331111, 331513,

33121, 331221,

331511, 33651,

336611, 482111,

3369, 331316,

336991, 336211,

336112, 336213,

336214, 336399,

326291, 326299,

332311, 332312,

336212, 336999,

33635, 56121, 8111,

56211

MACT, see 40 CFR Part 63

Subpart MMMM

U.S. EPA. 1995. Profile of the Fabricated

Metal Products Industry. Office of the

Compliance Sector Notebook Project,

Washington, D.C., September 1995. 

EPA/310-R-95-007. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/fabr

ic.html

U.S. EPA. 1995. Profile of the Stone, Clay,

Glass and Concrete Industry. Office of

Compliance Sector Notebook Project,

Washington, D.C., September 1995. 

EPA/310-R-95-017. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/ston

e.html
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-5

Auto & Light Duty

Truck (Surface

Coating) (0702)

toluene; xylene;

glycol ethers; methyl

ethyl ketone; methyl

isobutyl ketone;

ethylbenzene;

methanol

NAICS: 336111,

336112, 336211

MACT, see 40 CFR Part 63

Subpart IIII

U.S. EPA. 1995. Profile of the Motor

Vehicle Assembly Industry. Office of

Compliance Sector Notebook Project,

Washington, D.C., September 1995. 

EPA/310-R-95-009. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/mot

or.html

U.S. EPA. 2002. Regulatory Impact

Analysis for the Proposed Automobile and

Light Duty Truck Coating NESHAP. Final

Report, Washington, D.C., October 2002. 

EPA-452/R-01-013. Available at:

http://www.epa.gov/ttn/atw/auto/autoriap.pd

f

U.S. EPA. 1997. U.S. Auto Assembly Plants

and Their Communities -- Environmental,

Economic, and Demographic Profile. 

Common Sense Initiative Automobile

Manufacturing Sector. Washington, D.C.,

December 1997. Available at:

http://www.epa.gov/oar/opar/auto/

Boat Manufacturing

(1305)

styrene; methyl

methacrylate;

methylene chloride

(dichloromethane);

toluene; xylene; nhexane; methyl ethyl

ketone; methyl

isobutyl ketone;

methyl chloroform

(1,1,1-

trichloroethane)

SIC: 3731, 3732

NAICS: 336612

MACT, see 40 CFR Part 63

Subpart VVVV

U.S. EPA. 1997. Profile of the Shipbuilding

and Repair Industry. Office of Compliance

Sector Notebook Project. Washington, D.C.,

November 1997. EPA/310-R-97-008. 

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/ship

.html
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-6

Brick and Structural

Clay Products

Manufacturing (0414)

hydrogen fluoride;

hydrogen chloride;

antimony; arsenic;

beryllium; cadmium;

chromium; cobalt;

mercury; manganese;

nickel; lead;

selenium

SIC: 3251, 3253, 3259

NAICS: 327121,

327122, 327123

MACT, see 40 CFR Part 63

Subpart JJJJJ

U.S. EPA. 1995. Profile of the Stone, Clay,

Glass and Concrete Industry. Office of

Compliance Sector Notebook Project. 

Washington, D.C., September 1995. 

EPA/310-R-95-017. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/ston

e.html

Butyl Rubber

Production (1307)

n-hexane; 1,3-

butadiene;

acrylonitrile; methyl

chloride; hydrogen

chloride; carbon

tetrachloride;

chloroprene; toluene

SIC: 2821, 2822 

NAICS: 325211,

325212

MACT, see 40 CFR Part 63

Subpart U

U.S. EPA. 1995. Profile of the Rubber and

Plastics Industry. Office of Compliance

Sector Notebook Project, Washington, D.C.,

September 1995. EPA/310-R-95-016. 

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/rub

ber.html

Carbon Black

Production (1415)

cyanide compounds;

acrylonitrile;

acetonitrile; carbonyl

sulfide; carbon

disulfide; benzene;

1,3 butadiene;

toluene; 2,4 toluene

diisocyanate

SIC: 2895

NAICS: 325182

General MACT, see 40 CFR

Part 63 YY

U.S. EPA. 2002. Profile of the Organic

Chemical Industry. Office of Compliance

Sector Notebook Project, Washington, D.C.,

November 2002. EPA/310-R-02-001. 

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/org

anic.html

Carbonyl Sulfide

(COS) Production

(1604)

toluene; methanol;

xylene; hydrogen

chloride; methylene

chloride

NAICS: 3251, 3252,

3253, 3254, 3255,

3256, 3259

MACT, see 40 CFR Part 63

FFFF

(General MACT)

U.S. EPA. 2002. Profile of the Organic

Chemical Industry, Second Edition (2002). 

Office of Compliance Sector Notebook

Project, Washington, D.C., November 2002. 

EPA/310-R-02-001. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/org

anic.html
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-7

Cellulose Products

Manufacturing (1349)

carbon disulfide;

carbonyl sulfide;

ethylene oxide;

methanol; methyl

chloride; propylene

oxide; toluene

SIC: 2819, 2821,

2823, 2869, 3089

NAICS: 325188,

325199, 325211,

325221, 326121,

326199

MACT, see 40 CFR Part 63

UUUU

U.S. EPA. 2002. Profile of the Pulp and

Paper Industry, 2nd Edition. Office of

Compliance Sector Notebook Project,

Washington, D.C., November 2002. 

EPA/310-R-02-002. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/pul

p.html

U.S. EPA. 1997. Profile of the Plastic

Resins and Man-made Fibers Industry. 

Office of Compliance Sector Notebook

Project, Washington, D.C., September 1997. 

EPA/310-R-97-008. Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/plas

tic.html

Mercury Cell ChlorAlkali Plants (Formerly

Chlorine Production)

SIC: chlorine 2812 EPA proposes not to regulate

chlorine and hydrochloric acid

(HCl) emissions for the Chlorine

Production source category.

U.S. EPA. 1995. Profile of the Inorganic

Chemical Industry. Office of Compliance

Sector Notebook Project, Washington, D.C.,

September 1995. EPA/310-R-95-004. 

Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/inor

ganic.html

Chromic Acid

Anodizing (1607)

chromium NAICS: 332, 333,

334, 335, 336 

MACT, see 40 CFR Part 63

Subpart N

U.S. EPA. 1993. Chromium Emissions from

Chromium Electroplating and Chromic Acid

Anodizing Operations. Background

Information for Proposed Standards,

Washington, D.C., July 1993. EPA 453/R93-030a and EPA 453/r-93-030b, Volumes 1

and 2. Available at: 

http://www.epa.gov/ttn/atw/chrome/chromep

g.html
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-8

Clay Ceramics

Manufacturing (0415)

hydrogen flouride;

hydrogen chloride;

antimony; arsenic;

beryllium; cadmium;

chromium; cobalt;

mercury; manganese;

nickel; lead;

selenium

SIC: 3253, 3261

NAICS: 327122,

327111

MACT, see 40 CFR Part 63

Subpart KKKKK

U.S. EPA. 1995. Profile of the Stone, Clay,

Glass and Concrete Industry. Office of

Compliance Sector Notebook Project. 

Washington, D.C., September 1995. 

EPA/310-R-95-017. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/ston

e.html 

Coke Ovens: 

Charging, Top Side,

and Door Leaks (0302)

coal tar (benzene,

toluene, and xylene);

creosote; coal tar

pitch; polycyclic

aromatic

hydrocarbons

(benzo(a)pyrene,

benzanthracene,

chrysene,

phenanthrene)

NAICS: 331111,

324199

MACT, see 40 CFR Part 63

Subpart L

U.S. EPA. 1995. Profile of the Petroleum

Refining Industry. Office of Compliance,

Sector Notebook Project. Washington, D.C.,

September 1995. EPA/310-R-95-013. 

Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/petr

oleum.html

Coke Ovens: Pushing,

Quenching, & Battery

Stacks (0303)

polycyclic organic

matter; polynuclear

aromatic

hydrocarbons;

benzene; toluene;

xylene

NAICS: 331111,

324199

MACT, see 40 CFR Part 63

Subpart CCCCC

U.S. EPA. 1995. Profile of the Petroleum

Refining Industry. Office of Compliance,

Sector Notebook Project. Washington, D.C.,

September 1995. EPA/310-R-95-013. 

Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/petr

oleum.html

Commercial

Sterilization Facilities

(1609)

ethylene oxide NAICS: 3391 MACT, see 40 CFR Part 63

Subpart O 

U.S. EPA. 1997. Ethylene Oxide

Commercial Sterilization and Fumigation

Operations. NESHAP Implementation

Document. Washington, D.C., September,

1997. EPA-456/R-004. Available at:

http://www.epa.gov/ttn/atw/eo/eoguide.pdf
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-9

Cyanide Chemicals

Manufacturing (1405)

cyanide compounds;

acrylonitrile;

acetonitrile; carbonyl

sulfide; carbon

disulfide; benzene;

1,3 butadiene;

toluene; 2,4 toluene

diisocyanate

SIC: 2819, 2869

NAICS: 325188,

325199

MACT, see 40 CFR Part 63 YY

(General MACT)

Decorative Chromium

Electroplating (1610)

chromium NAICS: 332, 333,

334, 335, 336 

MACT, see 40 CFR Part 63

Subpart N

Dry Cleaning: 

Perchloroethylene

(1643)

perchloroethylene NAICS: 8123 MACT, see 40 CFR Part 63

Subpart M

U.S. EPA. 1995. Profile of the Dry Cleaning

Industry. Office of Compliance Sector

Notebook Project, Washington, D.C.,

September 1995. EPA/310-R-95-001.

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/dry.

html
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-10

Engine Test Facilities

(0101)

toluene; benzene;

mixed xylenes; 1,3-

butadiene

SIC: 3511, 3519,

3523, 3524, 3531,

3559, 3566, 3599,

3621, 3711, 3714,

3721, 3724, 3761,

3764, 4226, 4512,

4581, 5541, 7538,

7539, 7699, 8299,

8711, 8731, 8734,

8741, 9661, 9711

NAICS: 54171,

92711, 92811, 332212

333111, 333112,

333120, 333319,

333611, 333612,

333618, 335312,

336111, 336112,

336120, 336312,

336350, 336399,

336411, 336412,

336414, 336415,

336992, 481111,

488190, 541380,

611692, 811111,

811118, 811310,

811411

MACT, see 40 CFR Part 63

Subpart PPPPP

Epichlorohydrin

Elastomers Production

(1311)

n-hexane; 1,3-

butadiene;

acrylonitrile; methyl

chloride; hydrogen

chloride; carbon

tetrachloride;

chloroprene; toluene

SIC: 2821, 2822 

NAICS: 325211,

325212

MACT, see 40 CFR Part 63

Subpart U
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-11

Epoxy Resins

Production (1312)

epichlorohydrin,

methanol,

hydrochloric acid

SIC: 2821, 2823, 2824 MACT, see 40 CFR Part 63

Subpart W

U.S. EPA. 1997. Profile of the Plastic Resins

and Man-made Fibers Industry. Office of

Compliance Sector Notebook Project,

Washington, DC, September 1997. 

EPA/310-R-97-008. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/plas

tic.html

Ethylene Processes

(1635)

cyanide compounds;

acrylonitrile;

acetonitrile; carbonyl

sulfide; carbon

disulfide; benzene;

1,3 butadiene;

toluene; 2,4 toluene

diisocyanate

SIC: 2869

NAICS: 325110

MACT, see 40 CFR Part 63 YY U.S. EPA. 1997. Profile of the Plastic Resins

and Man-made Fibers Industry. Office of

Compliance Sector Notebook Project,

Washington, DC. EPA/310-R-97-006.

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/plas

tic.html

Ethylene-Propylene

Rubber Production

(1313)

n-hexane; 1,3-

butadiene;

acrylonitrile; methyl

chloride; hydrogen

chloride; carbon

tetrachloride;

chloroprene; toluene

SIC: 2821, 2822 

NAICS: 325211,

325212

MACT, see 40 CFR Part 63

Subpart U

U.S. EPA. 1995. Profile of the Rubber and

Plastics Industry. Office of Compliance

Sector Notebook Project, Washington, DC,

September 1995. EPA/310-R-95-016.

Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/rub

ber.html

Ferroalloys Production

(0304)

ferromanganese;

silicomanganese;

nickel compounds

SIC: 3313 MACT, see 40 CFR Part 63

Subpart XXX

Flexible Polyurethane

Foam Fabrication

Operations (1341)

hydrochloric acid;

2,4-toluene

diisocyanate;

hydrogen cyanide;

methylene chloride

SIC: 3086 

NAICS: 32615

MACT, see 40 CFR Part 63

Subpart MMMMM

U.S. EPA. 1995. Profile of the Wood

Furniture and Fixtures Industry. Office of

Compliance Sector Notebook Project,

Washington, D.C., September 1995. 

EPA/310-R-95-003. 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/woo

d.html 
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-12

Flexible Polyurethane

Foam Production

(1314)

methylene chloride;

2,4-toluene

diisocyanate; methyl

chloroform;

methylene diphenyl

diisocyanate;

propylene oxide;

diethanolamine;

methyl ethyl ketone;

methanol; toluene

SIC: 3086

NAICS: 32615

MACT, see 40 CFR Part 63

Subpart III

U.S. EPA. 1995. Profile of the Wood

Furniture and Fixtures Industry. Office of

Compliance Sector Notebook Project,

Washington, D.C., September 1995. 

EPA/310-R-95-003. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/woo

d.html 

Friction Products

Manufacturing (1636)

n-hexane; toluene;

trichloroethylene

NAICS: 33634,

327999, 333613

MACT, see 40 CFR Part 63

QQQQQ

Fumed Silica

Production (1406)

hydrochloric acid;

chlorine

SIC: 2819, 2821, 2869

NAICS: 325188,

325211, 325199

MACT, see 40 CFR Part 63

Subpart NNNNN

Gasoline Distribution

(Stage I) (0601)

benzene; toluene;

hexane; ethyl

benzene;

naphthalene;

cumene; xylenes; nhexane; 2, 2, 4-

trimethylpentane;

methyl tert-butyl

ether

SIC: 2911, 4226,

4613, 5171

NAICS: 324110,

493190, 486910,

422710

MACT, see 40 CFR Part 63

Subpart R

U.S. EPA. 1995. Profile of the Petroleum

Refining Industry. Office of Compliance

Sector Notebook Project, Washington, D.C.,

September 1995. EPA/310-R-95-013.

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/petr

oleum.html.

Hard Chromium

Electroplating (1615)

chromium NAICS: 332, 333,

334, 335, 336

MACT, see 40 CFR Part 63

Subpart N
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-13

Hazardous Waste

Incineration (0801)

chlorinated dioxins

and furans;

particulate matter (as

a surrogate for

antimony, cobalt,

manganese, nickel,

and selenium);

carbon monoxide;

mercury; lead;

cadmium; arsenic;

beryllium;

chromium; hydrogen

chloride and chlorine

gas (combined);

hydrocarbons

MACT, see 40 CFR Parts 63,

261 and 270

U.S. EPA. Hazardous Waste Combustion

NESHAP Toolkit.

Available at:

http://www.epa.gov/epaoswer/hazwaste/com

bust/toolkit/index.htm

Hydrochloric Acid

Production (1407)

hydrochloric acid;

chlorine

SIC: 2819, 2821, 2869

NAICS: 325188,

325211, 325199

MACT, see 40 CFR Part 63

Subpart NNNNN

None found at this writing.

Hydrogen Fluoride

Production (1409)

SIC: 2819

NAICS: 325188 

MACT, see 40 CFR Part 63 YY

(General MACT)

U.S. EPA. Profile of the Plastic Resins and

Man-made Fibers Industry. Office of

Compliance Sector Notebook Project,

Washington, D.C., September 1997.

EPA/310-R-97-006 . Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/plas

tic.html

Hypalon (TM)

Production (1315)

n-hexane; 1,3-

butadiene;

acrylonitrile; methyl

chloride; hydrogen

chloride; carbon

tetrachloride;

chloroprene; toluene

SIC: 2821, 2822 

NAICS: 325211,

325212

MACT, see 40 CFR Part 63

Subpart U

None found at this writing.
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-14

Industrial/Commercial/

Institutional Boilers &

Process Heaters (0107)

arsenic; cadmium;

chromium; hydrogen

chloride; hydrogen

fluoride; lead;

manganese; mercury;

nickel

SIC: 13, 24, 26, 28,

29, 30, 33, 34, 37, 49,

80, 82

NAICS: 211, 221,

316, 321, 322, 324,

325, 326, 331, 332,

336, 339, 611, 622 

MACT, see 40 CFR Part 63

Subpart DDDDD

U.S. EPA. 1999. Profile of Oil and Gas

Extraction Industry. Office of Compliance

Sector Notebook Project, Washington, D.C.,

October 2000. EPA/310-R-99-006. 

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/oil.

html.

Also see Profile of Lumber and Wood

Products Industry, Profile of Organic and

Inorganic Chemical Manufacturing Industry,

Profile of Petroleum Refining Industry, and

Profile of Rubber and Plastic Industry. 

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/index.html 

Industrial Cooling

Towers (1619)

chromium

compounds

MACT, see 40 CFR Part 63

Subpart Q

U.S. EPA. 1995. Profile of the Petroleum

Refining Industry. Office of Compliance,

Sector Notebook Project. Washington, D.C.,

September 1995. EPA/310-R-95-013. 

Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/petr

oleum.html

U.S. EPA. 2001. Profile of the Organic

Chemical Industry. Office of Compliance

Assistance and Sector Programs Division. 

Washington, D.C., September 2001.

EPA/310/R-02-001. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/org

anic.html
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-15

Integrated Iron & Steel

Manufacturing (0305)

metals (primarily

manganese and lead);

polycyclic organic

matter; benzene;

carbon disulfide

SIC: 3312

NAICS: 331111

MACT, see 40 CFR Part 63

Subpart FFFFF

U.S. EPA. 1995. Profile of the Iron and

Steel Industry. Office of Compliance Sector

Notebook Project, Washington, D.C.,

September 1995. EPA/310-R-95-005.

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/iron

.html 

Iron Foundries (0308) lead; manganese;

cadmium; chromium;

nickel;

acetophenone;

benzene; cumene;

dibenzofurans;

dioxins;

formaldehyde;

methanol;

naphthalene; phenol;

pyrene; toluene;

triethylamine; xylene

NAICS: 331511 MACT, see 40 CFR Part 63

Subpart EEEEE

U.S. EPA. 1995. Profile of the Iron and

Steel Industry. Office of Compliance Sector

Notebook Project, Washington, D.C.,

September 1995. EPA/310-R-95-005.

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/iron

.html 

Large Appliance

(Surface Coating)

(0704)

glycol ethers;

methylene diphenyl

diisocyanate; methyl

ethyl ketone; toluene;

xylene

NAICS: 333312,

333319, 333415,

335221, 335222,

335224, 335228

MACT, see 40 CFR Part 63

Subpart NNNN

U.S. EPA. 1995. Profile of the Dry Cleaning

Industry. Office of Compliance Sector

Notebook Project, Washington, D.C.,

September 1995. EPA/310-R-95-001. 

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/dry.

html. 

Leather Tanning &

Finishing Operations

(1634)

glycol ethers;

toluene; xylene

SIC: 3111

NAICS: 3161

MACT, see 40 CFR Part 63

Subpart TTTT

None found as of this writing
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-16

Light Weight

Aggregate

Manufacturing (0417)

toluene; methanol;

methyl ethyl ketone;

xylenes; phenol;

methylene chloride;

ethylene glycol;

glycol ethers;

hexane; methyl

isobutyl ketone;

cresols and cresylic

acid;

dimethylformamide;

vinyl acetate;

formaldehyde; ethyl

benzene

NAICS: 322211,

322212, 322221,

322222, 322223,

322224, 322225,

322226, 322299,

323111, 323116,

325992, 326111,

326112, 326113,

32613, 326192,

32791, 332999,

339944 

See MACT in 40 CFR Part 63

Subpart JJJJ

None found as of this writing

Lime Manufacturing

(0408)

hydrogen chloride; 

antimony; arsenic;

beryllium; cadmium;

chromium; lead;

manganese; mercury;

nickel; selenium

NAICS: 32741,

33111, 3314

MACT, see 40 CFR Part 63

Subpart AAAAA

None found at this writing.

Magnetic Tapes

(Surface Coating)

(0705)

methyl ethyl ketone;

toluene; methyl

isobutyl ketone;

toluene diisocyanate;

ethylene glycol;

methanol; xylenes;

ethyl benzene;

acetaldehyde;

chromium; cobalt

SIC: 3695, 2675 MACT, see 40 CFR Part 63

Subpart EE

Manufacture of

Nutritional Yeast

(1101)

acetaldehyde SIC: 2099

NAICS: 311999

MACT, see 40 CFR Part 63

Subpart CCCC
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-17

Marine Vessel Loading

Operations (0603)

benzene; toluene;

hexane

MACT, see 40 CFR Part 63

Subpart Y

U.S. EPA. 1997. Profile of the Water

Transportation Industry (Shipping and

Barging). Office of Compliance Sector

Notebook Project, Washington, D.C.,

September 1997. EPA/310-R-97-003.

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/wat

er.html

Metal Can (Surface

Coating) (0707)

ethylene glycol

monobutyl ether;

other glycol ethers;

xylenes; hexane;

methyl isobutyl

ketone; methyl ethyl

ketone 

NAICS: 332115,

332116, 332431,

332812, 332999

MACT, see 40 CFR Part 63

Subpart KKKK

U.S. EPA. 1995. Profile of the Metal

Fabrication Industry. Office of Compliance

Sector Notebook Project, Washington, D.C.,

September 1995. EPA/310-R-95-007.

Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/fabr

ic.html 

Metal Coil (Surface

Coating) (0708)

methyl ethyl ketone;

glycol ethers;

xylenes (isomers and

mixtures); toluene;

isophorone.

SIC: 34

NAICS: 332812,

331319, 332312,

332322, 332323,

332311, 33637,

332813, 332999,

333293, 336399,

325992, 42183,

323122, 339991,

326113, 32613,

32614, 331112,

331221, 33121,

331312, 331314,

331315

MACT, see 40 CFR Part 63

Subpart SSSS

U.S. EPA. 1995. Profile of the Metal

Fabrication Industry. Office of Compliance

Sector Notebook Project, Washington, D.C.,

September 1995. EPA/310-R-95-007.

Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/fabr

ic.html 
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-18

Metal Furniture

(Surface Coating)

(0709)

xylene; toluene;

ethylene glycol

monobutyl ether;

other glycol ethers;

ethylbenzene; methyl

ethyl ketone

NAICS: 81142,

337124, 337127,

337214, 337215,

339111 

MACT, see 40 CFR Part 63

Subpart RRRR

U.S. EPA. 1995. Profile of the Metal

Fabrication Industry. Office of Compliance

Sector Notebook Project, Washington, D.C.,

September 1995. EPA/310-R-95-007.

Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/fabr

ic.html

Methyl MethacrylateAcrylonitrileButadiene-Styrene

Production (1317)

styrene; acrylonitrile;

butadiene; ethylene

glycol; methanol;

acetaldehyde;

dioxane

SIC: 2821, 2822

NAICS: 325211,

325212

MACT, see 40 CFR Part 63 JJJ U.S. EPA. 2001. Polymers and Resins IV

Inspection Tool. Adopt-a-MACT

Compliance Tool, Washington, D.C.,

September 2001. Available at:

http://www.epa.gov/ttn/atw/pr4/privinspect.h

tml

Methyl MethacrylateButadiene-Styrene

Terpolymers

Production (1318)

styrene; acrylonitrile;

butadiene; ethylene

glycol; methanol;

acetaldehyde;

dioxane

SIC: 2821, 2822

NAICS: 325211,

325212

MACT, see 40 CFR Part 63 JJJ U.S. EPA. 2001. Polymers and Resins IV

Inspection Tool. Adopt-a-MACT

Compliance Tool, Washington, D.C.,

September 2001. Available at:

http://www.epa.gov/ttn/atw/pr4/privinspect.h

tml

Mineral Wool

Production (0409)

carbonyl sulfide;

nine hazardous

metals;

formaldehyde;

phenol

SIC: 3296 MACT, see 40 CFR Part 63

DDD

Miscellaneous Coatings

Manufacturing (1642)

toluene; xylene;

glycol ethers; methyl

ethyl ketone, and

methyl isobutyl

ketone

NAICS: 3255 MACT, see 40 CFR Part 63

Subpart HHHHH

U.S. EPA. 1995. Profile of the Metal

Fabrication Industry. Office of Compliance

Sector Notebook Project. Washington, D.C.,

September 1995. EPA/310-R-95-007.

Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/fabr

ic.html 
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-19

Miscellaneous Metal

Parts & Products

(Surface Coating)

(0710)

xylene; toluene;

methyl ethyl ketone;

phenol;

cresols/cresylic acid;

2-butoxyethanol;

styrene; methyl

isobutyl ketone; ethyl

benzene; glycol

ethers

NAICS: 335312,

336111, 336211,

336312, 33632,

33633, 33634, 33637,

336399, 331316,

331524, 332321,

332323, 33312,

333611, 333618,

332312, 332722,

332813, 332991,

332999, 334119,

336413, 339999,

33612, 336211,

331319, 331422,

335929, 332311,

33242, 81131,

322214, 326199,

331513, 332439,

331111, 331513,

33121, 331221,

331511, 33651,

336611, 482111,

3369, 331316,

336991, 336211,

336112, 336213,

336214, 336399,

326291, 326299,

332311, 332312,

336212, 336999,

33635, 56121, 8111,

56211

MACT, see 40 CFR Part 63

Subpart MMMM

U.S. EPA. 1995. Profile of the Metal

Fabrication Industry. Office of Compliance

Sector Notebook Project. Washington, D.C.,

September 1995. EPA/310-R-95-007.

Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/fabr

ic.html
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-20

Miscellaneous Organic

Chemical Products &

Processes (1641)

toluene; methanol;

xylene; methyl ethyl

ketone; ethyl

benzene; methyl

isobutyl ketone;

hydrogen chloride;

vinyl acetate

NAICS: 3251, 3252,

3253, 3254, 3255,

3256, 3259

MACT, see 40 CFR Part 63

Subpart FFFF

U.S. EPA. 2002. Profile of the Organic

Chemical Industry, 2nd Edition. Office of

Compliance Sector Notebook Project.

Washington, DC., November 2002.

EPA/310-R-02-001. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/org

anic.html.

Municipal Landfills

(0802)

vinyl chloride; ethyl

benzene; toluene;

benzene

SIC: 4953, 9511

NAICS: 562212,

924110

MACT, see 40 CFR Part 63

Subpart AAAA

None found as of this writing

Natural Gas

Transmission &

Storage (0504)

benzene; toluene;

ethyl benzene; mixed

xylenes; n-hexane

SIC: 40,42,46, 49,

1321 

NAICS: 211112

Note: Condensate tank

batteries, glycol

dehydration units,

natural gas processing

plants, and natural gas

transmission and

storage facilities not

included.

MACT, see 40 CFR Part 63

Subpart HHH

U.S. EPA. 1997. Profile of the Ground

Transportation Industry - Railroad,

Trucking, and Pipeline. Office of

Compliance Sector Notebook Project,

Washington, D.C., September 1997.

EPA/310-R-97-002. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/gro

und.html 

Neoprene Production

(1320)

n-hexane; 1,3-

butadiene;

acrylonitrile; methyl

chloride; hydrogen

chloride; carbon

tetrachloride;

chloroprene; toluene

SIC: 2821, 2822

NAICS: 325211,

325212

MACT, see 40 CFR Part 63

Subpart U

U.S. EPA. 1997. Profile of Plastic Resins

and Man-Made Fibers Industry. Office of

Compliance Sector Notebook Project,

Washington, D.C., September 1997. 

EPA/310-R-97-006. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/plas

tic.html
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-21

Nitrile Butadiene

Rubber Production

(1321)

n-hexane; 1,3-

butadiene;

acrylonitrile; methyl

chloride; hydrogen

chloride; carbon

tetrachloride;

chloroprene; toluene

SIC: 2821, 2822

NAICS: 325211,

325212

MACT, see 40 CFR Part 63

Subpart U

U.S. EPA. 1995. Profile of the Rubber and

Plastic Industry. Office of Compliance

Sector Notebook Project, Washington, D.C.,

September 1995. EPA/310-R-95-016.

Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/rub

ber.html

Nitrile Resins

Production (1342)

Styrene, n-hexane,

1,3-

butadiene,

acrylonitrile, methyl

chloride, hydrogen

chloride, carbon

tetrachloride,

chloroprene, toluene

MACT, see 40 CFR Part 63

Subpart U

U.S. EPA. 1997. Profile of Plastic Resins

and Man-Made Fibers Industry. Office of

Compliance Sector Notebook Project,

Washington, D.C., September 1997. 

EPA/310-R-97-006. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/plas

tic.html.

Off-Site Waste and

Recovery Operations

(0806)

benzene, methylene

chloride

MACT, see 40 CFR Part 63

Subpart DD

None found at this writing.

Oil & Natural Gas

Production (0501)

benzene; toluene;

ethyl benzene; mixed

xylenes; n-hexane

SIC: 1311, 1321,

1381, 1382, 1389

NAICS: 211112

(Condensate tank

batteries, glycol

dehydration units,

natural gas processing

plants, and natural gas

transmission and

storage facilities.)

MACT, see 40 CFR Part 63 HH U.S. EPA. 1999. Profile of the Oil and Gas

Extraction Industry. Office of Compliance

Sector Notebook Project, Washington, D.C.

EPA/310-R-99-006. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/oil.

html
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-22

Organic Liquids

Distribution (NonGasoline) (0602)

benzene;

ethylbenzene;

toluene; vinyl

chloride; xylenes 

SIC: 2821, 2865,

2869, 2911, 4226,

4612, 5169, 5171

NAICS: 325211,

325192, 325188,

32411, 49311, 49319,

48611, 42269, 42271

MACT, see 40 CFR Part 63

Subpart EEEE

U.S. EPA. 1997. Profile of the Ground

Transportation Industry - Railroad,

Trucking and Pipeline. Office of

Compliance Sector Notebook Project.

Washington, D.C., September 1997.

EPA/310-R-97-002.

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/gro

und.html 

U.S. EPA. 1995. Profile of the Petroleum

Refining Industry. Office of Compliance

Sector Notebook Project. Washington, D.C.,

September 1995. EPA/310-R-95-013.

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/petr

oleum.html

U.S. EPA. 2002. Organic Chemical

Manufacturing Industry. Office of

Compliance Sector Notebook Project.

Washington, D.C., November 2002.

EPA/310-R-02-001. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/org

anic.html
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-23

Paper & Other Webs

(Surface Coating)

(0711)

toluene; methanol;

methyl ethyl ketone;

xylenes; phenol;

methylene chloride;

ethylene glycol;

glycol ethers;

hexane; methyl

isobutyl ketone;

cresols and cresylic

acid;

dimethylformamide;

vinyl acetate;

formaldehyde; ethyl

benzene

NAICS: 322211,

322212, 322221,

322222, 322223,

322224, 322225,

322226, 322299,

323111, 323116,

325992, 326111,

326112, 326113,

32613, 326192,

32791, 332999,

339944 

MACT, see 40 CFR Part 63 JJJJ MACT Sources: Profile of the Pulp and

Paper Industry, 2nd Edition (2002).

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/pul

p.html

Pesticide Active

Ingredient Production

(0911)

toluene; methanol;

methyl chloride;

hydrogen chloride

SIC: 2869, 2879

NAICS: 32532,

325199

MACT, see 40 CFR Part 63

MMM

U.S. EPA. 2000. Profile of the Agricultural

Chemical, Pesticide, and Fertilizer Industry.

Office of Compliance Sector Notebook

Project, Washington, D.C., September 2000. 

EPA/310-R-00-003. Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/che

mical.html

Petroleum Refineries -

Catalytic Cracking,

Catalytic Reforming, &

Sulfur Plant Units

(0502)

hydrogen fluoride;

hydrogen chloride;

2,2,4-

trimethylpentane;

methyl tert butyl

ether; benzene;

naphthalene;

cresols/cresylic acid; 

phenol;

ethylbenzene; 

toluene; hexane;

xylenes; methyl ethyl

ketone

SIC: 2911 MACT, see 40 CFR Part 63

Subpart CC

U.S. EPA. 1995. Profile of the Petroleum

Refining Industry. Office of Compliance

Sector Notebook Project, Washington, D.C.,

September 1995. EPA/310-R-95-013.

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/petr

oleum.html
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-24

Petroleum Refineries -

Other Sources Not

Distinctly Listed

(0503)

benzene, toluene,

ethyl benzene,

2,2,4-trimethylpentan

e, cresols/cresylic

acid, ethylbenzene,

hexane, methyl ethyl

ketone

SIC: 2911 MACT, see 40 CFR Part 63

Subpart CC

U.S. EPA. 1995. Profile of the Petroleum

Refining Industry. Office of Compliance

Sector Notebook Project. Washington, D.C.,

September 1995. EPA/310-R-95-013.

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/petr

oleum.html.

Pharmaceuticals

Production (1201)

methylene chloride;

methanol; toluene;

hydrogen chloride;

dimethylformamide;

hexane

SIC: 2833, 2834 

NAICS: 32541,

325412

MACT, see 40 CFR Part 63

GGG

U.S. EPA. 1997. Profile of the

Pharmaceutical Industry. Office of

Compliance Sector Notebook Project.

Washington, D.C., September 1997.

EPA/310-R-97-005. Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/pha

rmaceutical.html

Phosphate Fertilizers

Production (1410)

hydrogen fluoride;

arsenic; beryllium;

cadmium; chromium;

manganese; mercury;

nickel; methyl

isobutyl ketone 

SIC: 2874

NAICS: 325314

MACT, see 40 CFR Part 63 BB U.S. EPA. 2000. Profile of the Agricultural

Chemical, Pesticide, and Fertilizer Industry. 

Office of Compliance Sector Notebook

Project. Washington, D.C., September 2000.

EPA/310-R-00-003. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/che

mical.html

Phosphoric Acid

Manufacturng (1411)

hydrogen fluoride;

arsenic; beryllium;

cadmium; chromium;

manganese; mercury;

nickel; methyl

isobutyl ketone 

SIC: 2874

NAICS: 325314

MACT, see 40 CFR Part 63 AA U.S. EPA. 2000. Profile of the Agricultural

Chemical, Pesticide, and Fertilizer Industry.

Office of Compliance Sector Notebook

Project. Washington, D.C., September 2000.

EPA/310-R-00-003. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/che

mical.html
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-25

Plastic Parts &

Products (Surface

Coating) (0712)

methyl ethyl ketone;

methyl isobutyl

ketone; toluene;

ethylene glycol

monobutyl ether;

other glycol ethers;

xylenes

NAICS: 32615,

32614, 33422, 33992,

326199, 333313,

336211, 336212,

336213, 336214,

336399, 336999,

337214, 339111,

339112, 339999 

MACT, see 40 CFR Part 63

Subpart PPPP

U.S. EPA. 1995. Profile of the Motor

Vehicle Assembly Industry. Office of

Compliance Sector Notebook Project.

Washington, D.C., September 1995. 

EPA/310-R-95-009. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/mot

or.html 

Plywood and

Composite Wood

Products (1624)

acetaldehyde;

acrolein;

formaldehyde;

methanol; phenol;

propionaldehyde

SIC: 2421, 2435,

2436, 2439, 2493

NAICS: 321211,

321212, 321213,

321219, 321999

MACT, see 40 CFR Part 63

Subpart DDDD

The Plywood and Composite Wood Products

MACT was proposed on January 9, 2003.

The comment period ended on March 10,

2003. The final rule will most likely be

promulgated in March 2004, with a

compliance date of March 2007. 

Polybutadiene Rubber

Production (1325)

styrene; n-hexane;

1,3- butadiene;

acrylonitrile; methyl

chloride; hydrogen

chloride; carbon

tetrachloride;

chloroprene; toluene

SIC: 2821, 2822

NAICS: 325211,

325212

MACT, see 40 CFR Part 63

Subpart U

U.S. EPA. 1995. Profile of the Rubber and

Plastic Industry. Office of Compliance

Sector Notebook Project. Washington, D.C.,

September 1995. EPA/310-R-95-016.

Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/rub

ber.html

Polycarbonates

Production (1326)

TOC, organic HAPs SIC: 2869

NAICS: 325199

MACT, see 40 CFR Part 63 YY

(Generic MACT)

U.S. EPA. 1997. Profile of the Plastic Resins

and Man-made Fibers Industry. Office of

Compliance Sector Notebook Project.

Washington, D.C., September 1997.

EPA/310-R-97-006 . Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/plas

tic.html

Polyether Polyols

Production (1625)

ethylene oxide;

propylene oxide;

hexane; toluene

SIC: 2843, 2869

NAICS: 325199,

325613

MACT, see 40 CFR Part 63 PPP None found at this writing.
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-26

Polyethylene

Terephthalate

Production (1328)

styrene; acrylonitrile;

butadiene; ethylene

glycol; methanol;

acetaldehyde;

dioxane

SIC: 2821, 2822

NAICS: 325211,

325212

MACT, see 40 CFR Part 63 JJJ U.S. EPA. 2001. Polymers and Resins IV

Inspection Tool. Adopt-a-MACT

Compliance Tool, Washington, D.C.,

September 2001. Available at:

http://www.epa.gov/ttn/atw/pr4/privinspect.h

tml

Polystyrene Production

(1331)

styrene; acrylonitrile;

butadiene; ethylene

glycol; methanol;

acetaldehyde;

dioxane

SIC: 2821, 2822

NAICS: 325211,

325212

MACT, see 40 CFR Part 63 JJJ U.S. EPA. 2001. Polymers and Resins IV

Inspection Tool. Adopt-a-MACT

Compliance Tool, Washington, D.C.,

September 2001. Available at:

http://www.epa.gov/ttn/atw/pr4/privinspect.h

tml

Polysulfide Rubber

Production (1332)

styrene; n-hexane;

1,3- butadiene;

acrylonitrile; methyl

chloride; hydrogen

chloride; carbon

tetrachloride;

chloroprene; toluene

SIC: 30 MACT, see 40 CFR Part 63

Subpart U

U.S. EPA. 1995. Profile of the Rubber and

Plastic Industry. Office of Compliance

Sector Notebook Project. Washington, D.C.,

September 1995. EPA/310-R-95-016.

Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/rub

ber.html

Polyvinyl Chloride &

Copolymers Production

(1336)

vinyl chloride;

vinylidene chloride

(1,1

dichloroethylene);

vinyl acetate

SIC: 2821

NAICS: 325211

MACT, see 40 CFR Part 63 J None found as of this writing
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-27

Portland Cement

Manufacturing (0410)

acetaldehyde;

arsenic; benzene;

cadmium; chromium;

chlorobenzene;

dibenzofurans;

formaldehyde;

hexane; hydrogen

chloride; lead;

manganese; mercury;

naphthalene; nickel;

phenol; polycyclic

organic matter;

selenium; styrene;

2,3,7,8-

tetrachlorodibenzo-pdioxin; toluene;

xylenes

SIC: 3241

NAICS: 32731

MACT, see 40 CFR Part 63

Subpart LLL

U.S. EPA. 1995. Profile of the Stone, Clay,

Glass and Concrete Industry. Office of

Compliance Sector Notebook Project.

Washington, D.C., September 1995.

EPA/310-R-95-017. 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/ston

e.html 

Primary Aluminum

Production (0201)

hydrogen flouride;

polycyclic aromatic

hydrocarbons

NAICS: 331312 MACT, see 40 CFR Part 63

Subpart LL

U.S. EPA. 1995. Profile of the Nonferrous

Metals Industry. Office of Compliance

Sector Notebook Project. Washington, D.C.,

September 1995. EPA/310-R-95-010.

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/non

ferrous.html

Primary Copper

Smelting (0203)

antimony; arsenic;

beryllium; cadmium;

cobalt; lead;

manganese; nickel;

selenium

SIC: 3339 MACT, see 40 CFR Part 63

Subpart QQQ

None found at this writing.

Primary Lead Smelting

(0204)

arsenic; antimony;

cadmium

SIC: 3339 MACT, see 40 CFR Part 63

Subpart TTT

None found at this writing.

Primary Magnesium

Refining (0207)

chlorine;

hydrochloric acid;

dioxin/furan; trace

amounts of several

HAP metals

NAICS: 331419 MACT, see 40 CFR Part 63

Subpart TTTTT

None found at this writing.
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-28

Printing, Coating &

Dyeing Of Fabrics

(0713)

toluene; methyl ethyl

ketone; methanol;

xylenes; methyl

isobutyl ketone;

methylene chloride;

n-hexane;

trichloroethylene;

n,n-dimethyl

formamide.; 1,1,1-

trichloroethane;

naphthalene; ethyl

benzene; glycol

ethers (ethylene

glycol); biphenyl;

styrene

NAICS: 31321,

31322, 313241,

NAICS: 313311,

313312, 313320,

314110

MACT, see 40 CFR Part 63

Subpart OOOO

U.S. EPA. 1997. Profile of the Textiles

Industry. Office of Compliance Sector

Notebook Project, Washington, D.C.,

September 1997. EPA/310-R-97-009.

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/text

iles.html

Printing/Publishing

(Surface Coating)

(0714)

xylene; toluene;

ethylbenzene; methyl

ethyl ketone; methyl

isobutyl ketone;

methanol; ethylene

glycol; certain glycol

ethers

SIC: 2671, 2711,

2721, 2754, 2759

MACT, see 40 CFR Part 63

Subpart KK

U.S. EPA. 1995. Profile of the Printing

Industry. Office of Compliance Sector

Notebook Project, Washington, D.C.,

September 1995. EPA/310-R-95-014.

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/prin

ting.html

Publicly Owned

Treatment Works

(POTW) Emissions

(0803)

xylenes; methylene

chloride; toluene;

ethyl benzene;

chloroform;

tetrachloroethylene;

benzene; naphthalene

SIC: 4952

NAICS: 22132

MACT, see 40 CFR Part 63

Subpart VVV

None found at this writing.

Pulp & Paper

Production -

Combustion (Kraft,

Soda, Sulfite, & SemiChemical) (1626-2)

SIC: 2611, 2621,2631

NAICS: 32211,

32212, 32213

MACT, see 40 CFR Part 63

Subpart S

U.S. EPA. 2002. Profile of the Pulp and

Paper Industry, 2nd Edition. Office of

Compliance Sector Notebook Project,

Washington, D.C., November 2002. 

EPA/310-R-95-015. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/pul

p.html
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-29

Pulp & Paper

Production - NonCombustion (1626-1)

SIC 26 MACT, see 40 CFR Part 63

Subpart S

U.S. EPA. 2002. Profile of the Pulp and

Paper Industry, 2nd Edition. Office of

Compliance Sector Notebook Project,

Washington, D.C., November 2002. 

EPA/310-R-95-015. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/pul

p.html

Refractories Products

Manufacturing (0406)

ethylene glycol;

formaldehyde;

hydrogen fluoride;

hydrochloric acid;

methanol; phenol;

polycyclic organic

matter

NAICS: 327124,

327125

MACT, see 40 CFR Part 63

Subpart SSSSS

None found at this writing.

Reinforced Plastic

Composites Production

(1337)

styrene; methyl

methacrylate;

methylene chloride

(dichloromethane)

SIC: 2821, 3084,

3087, 3088, 3089,

3281, 3296, 3431,

3531, 3612, 3613,

3621, 3663, 3711,

3713, 3714, 3716,

3728, 3743, 3792,

3799

NAICS: 33312,

33612, 33651, 33653,

35313, 325211,

325991, 326122,

326191, 327991,

327993, 332998,

333422, 335311,

335312, 336112,

336211, 336213,

336214, 336399,

336413

MACT, see 40 CFR Part 63

Subpart WWWW

None found at this writing.
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-30

Rocket Engine Test

Firing (1627)

toluene, benzene,

mixed xylenes, 1,3-

butadiene

SIC: 3724, 3761,

3764, 9661, 9711 

NAICS: 336412,

336414 , 336415,

54171, 92711, 92811

MACT, see 40 CFR Part 63

Subpart PPPPP

U.S. EPA. 1997. Profile of the Air

Transportation Industry. Office of

Compliance Sector Notebook Project,

Washington, D.C., February 1998.

EPA/310-R-97-001. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/air.

html

Rubber Tire Production

(1631)

toluene; hexane SIC: 2296, 3011, 7534

NAICS: 314992,

326211, 326212

MACT, see 40 CFR Part 63

Subpart XXXX

U.S. EPA. Profile of the Rubber and Plastic

Industry. Office of Compliance Sector

Notebook Project, Washington, D.C.,

September 1995. EPA/310-R-95-016.

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/rub

ber.html

Secondary Aluminum

Production (0202)

hydrogen chloride,

hydrogen fluoride,

chlorine,

2,3,7,8-tetrachlorodi

benzo-p-dioxin,

organic HAPs,

particulate HAP

metals

SIC: 3341, 3334,

3353, 3354, 3355,

3363, 3365

NAICS: 331314,

331312, 331315,

331316, 331319,

331521, 331524 

MACT, see 40 CFR Part 63

Subpart RRR

None found at this writing.

Secondary Lead

Smelting (0205)

lead compounds;

arsenic compounds;

1,3-butadiene

NAICS: 331492 MACT, see 40 CFR Part 63

Subpart X

None found at this writing.

Semiconductor

Manufacturing (1629)

hydrochloric acid;

hydrogen flouride;

methanol; glycol

ethers; xylene

SIC: 3674

NAICS: 334413

MACT, see 40 CFR Part 63

Subpart BBBBB

U.S. EPA. 2001. National Emission

Standards for Hazardous Air Pollutants:

Semiconductor Manufacturing-Background

Information for Proposed Standards. Office

of Air Quality Planning and Standards,

Research Triangle Park, NC, February 2001.

Available at:

http://www.epa.gov/ttn/atw/semicon/smatr_b

id.pdf
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-31

Shipbuilding & Ship

Repair (Surface

Coating) (0715)

xylene; toluene;

ethylbenzene; methyl

ethyl ketone; methyl

isobutyl ketone;

ethylene glycol;

glycol ethers

SIC: 3731 MACT, see 40 CFR Part 63

Subpart II

U.S. EPA. 1997. Profile of the Shipbuilding

and Repair Industry. Office of Compliance

Sector Notebook Project, Washington, D.C.,

November 1997. EPA/310-R-97-008.

Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/ship

.html 

Site Remediation

(0805)

benzene; ethyl

benzene; toluene;

vinyl chloride;

xylenes; other

volatile organic

compounds

NAICS: 325211,

325192, 325188,

32411, 49311, 49319,

48611, 42269, 42271

MACT, see 40 CFR Part 63

Subpart GGGGG

Solvent Extraction for

Vegetable Oil

Production (1103)

n-hexane SIC: 2076, 2079

NAICS: 311223

MACT, see 40 CFR Part 63

Subpart GGGG

None found at this writing.

Spandex Production

(1003)

cyanide compounds;

acrylonitrile;

acetonitrile; carbonyl

sulfide; carbon

disulfide; benzene;

1,3 butadiene;

toluene; 2,4 toluene

diisocyanate

SIC: 2824

NAICS: 325222

MACT, see 40 CFR Part 63 YY U.S. EPA. 1997. Profile of the Plastic Resins

and Man-made Fibers Industry. Office of

Compliance Sector Notebook Project,

Washington, D.C., September 1997.

EPA/310-R-97-006. Available at:

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/plas

tic.html

Stationary Combustion

Turbines (0108)

formaldehyde;

toluene; benzene;

acetaldehyde

SIC: 1311, 1321,

4911, 4922, 4931

NAICS: 221, 2211,

211111, 211112,

486210

MACT, see 40 CFR Part 63

YYYY

Stationary Reciprocal 

Internal Combustion

Engines (0105)

formaldehyde;

acrolein; methanol;

acetaldehyde

SIC: 1311, 1321,

4911, 4922, 9711

NAICS: 2211, 48621,

92811, 211111,

211112

MACT, see 40 CFR Part 63

Subpart ZZZZ
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-32

Steel Pickling - HCL

Process (0310)

hydrochloric acid SIC: 3312, 3315, 3317 MACT, see 40 CFR Part 63

Subpart CCC

Styrene Acrylonitrile

Production (1338)

styrene; acrylonitrile;

butadiene; ethylene

glycol; methanol;

acetaldehyde;

dioxane

SIC: 2821, 2822

NAICS: 325211,

325212 

MACT, see 40 CFR Part 63 JJJ U.S. EPA. 2001. Polymers and Resins IV

Inspection Tool. Adopt-a-MACT

Compliance Tool, Washington, D.C.,

September 2001. Available at:

http://www.epa.gov/ttn/atw/pr4/privinspect.h

tml

Styrene-Butadiene

Rubber & Latex

Production (1339)

styrene; n-hexane;

1,3- butadiene;

acrylonitrile; methyl

chloride; hydrogen

chloride; carbon

tetrachloride;

chloroprene; toluene

SIC: 2821, 2822

NAICS: 325211,

325212

MACT, see 40 CFR Part 63

Subpart U

U.S. EPA. 1995. Profile of the Rubber and

Plastic Industry. Office of Compliance

Sector Notebook Program, Washington,

D.C., September 1995. EPA/310-R-95-016.

Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/rub

ber.html

Synthetic Organic

Chemical

Manufacturing (HON)

(1501)

toluene, methanol,

xylene, hydrogen

chloride, and

methylene chloride

NAICS: 3251, 3252,

3253, 3254, 3255,

3256, 3259

MACT, see 40 CFR Part 63

Subpart FFFF

and Miscellaneous Organic

NESHAP

Taconite Iron Ore

Processing (0411)

metal compounds

(such as manganese,

arsenic, lead, nickel,

chromium, and

mercury); products

of incomplete

combustion

(including

formaldehyde);

hydrogen chloride;

hydrogen fluoride

NAICS: 21221 MACT, see 40 CFR Part 63

Subpart RRRRR

None found at this writing.
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-33

Utility Boilers: Coal

(1808-1)

arsenic; cadmium;

chromium; hydrogen

chloride; hydrogen

fluoride; lead;

manganese; mercury;

nickel

SIC: 29

NAICS: 324

See 40 CFR Part 63 Subpart

DDDDD

None found at this writing.

Utility Boilers: Natural

Gas (1808-2)

arsenic; cadmium;

chromium; hydrogen

chloride; hydrogen

fluoride; lead;

manganese; mercury;

nickel

SIC: 13, 49

NAICS: 211, 221

See 40 CFR Part 63 Subpart

DDDDD

None found at this writing.

Utility Boilers: Oil

(1808-3)

arsenic; cadmium;

chromium; hydrogen

chloride; hydrogen

fluoride; lead;

manganese; mercury;

nickel

SIC: 24, 29

NAICS: 321, 324

See 40 CFR Part 63 Subpart

DDDDD

None found at this writing.

Wet-Formed Fiberglass

Mat Production (0413)

formaldehyde;

methanol; vinyl

acetate

SIC: 3229325

NAICS: 327212

MACT, see 40 CFR Part 63

Subpart HHHH

None found at this writing.

Wood Building

Products (Surface

Coating) (0703)

xylenes; toluene;

ethyl benzene;

ethylene glycol

monobutyl ether;

other glycol ethers;

methyl ethyl ketone;

methyl isobutyl

ketone; methanol;

styrene;

formaldehyde

SIC: 2421, 2426,

2431, 2435, 2436,

2493, 2499 

NAICS: 321211,

321212, 321219,

321911, 321918,

321999

Note: The subcategory

of the SIC and NAICS

code depends on the

final end use of the

product.

MACT, see 40 CFR Part 63

Subpart QQQQ

U.S. EPA. 1995. Profile of the Wood

Furniture and Fixtures Industry. Office of

Compliance Sector Notebook Project,

Washington, D.C., September 1995.

EPA/310-R-95-003. Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/woo

d.html
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-34

Wood Furniture

(Surface Coating)

(0716)

toluene; xylene;

methanol; methyl

ethyl ketone; methyl

isobutyl ketone;

glycol ethers;

formaldehyde

SIC: 2511, 2512,

2517, 2519, 2521,

2531, 2541

MACT, see 40 CFR Part 63

Subpart JJ

U.S. EPA. 1995. Profile of the Wood

Furniture and Fixtures Industry. Office of

Compliance Sector Notebook Project,

Washington, D.C., September 1995.

EPA/310-R-95-003. Available at: 

http://www.epa.gov/compliance/resources/p

ublications/assistance/sectors/notebooks/woo

d.html

Wool Fiberglass

Manufacturing (0412)

arsenic,

chromium, lead,

formaldehyde,

phenol, and

methanol

SIC: 3296 MACT, see 40 CFR Part 63

Subpart NNN

None found at this writing.

Mobile Sources

Mobile sources acetaldehyde,

acrolein, arsenic

compounds, benzene,

1,3-butadiene,

chromium

compounds, diesel

particulate matter,

diesel exhaust

organic gases,

dioxin/ furans,

ethylbenzene,

formaldehyde ,

n-hexane, lead

compounds,

manganese

compounds, mercury

compounds, MTBE,

naphthalene, nickel

compounds,

polycyclic organic

matter, styrene,

toluene, xylene

N/A Various, see

http://www.epa.gov/otaq/

EPA’s Office of Transportation Air Qualtiy

provides information on mobile source air

toxics at http://www.epa.gov/otaq/toxics.htm

In-depth information on desiel engine

exhaust can be found at

http://cfpub.epa.gov/ncea/cfm/recordisplay.c

fm?deid=29060&CFID=12048081&CFTOK

EN=92457493

The Health Effects Institute is an

independent, nonprofit corporation chartered

in 1980 to provide high-quality, impartial,

and relevant science on the health effects of

pollutants from motor vehicles and from

other sources in the environment (see

www.healtheffects.org).
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-35

Indoor Sources

Tobacco smoke Many, including

benzene, toluene, 

formaldehyde,

acrolein, Nnitrosdimethylamine, polycyclic

organic matter,

methyl chloride, 1,3-

butadiene, phenol,

catechol,

hydroquinone,

aniline, o-toluidine,

quinoline,

polychlorinated

dibenzo-p-dioxins,

nickel, cadmium,

polonium-210

N/A Voluntary programs to protect

children from the effects of

secondhand smoke

U.S. EPA. 1992. Respiratory Health Effects

of Passive Smoking: Lung Cancer and Other

Disorders. Office of Research and

Development and Office of Air and

Radiation, Washington, D.C., December

1992. EPA/600/6-90/006F. Available at:

http://cfpub.epa.gov/ncea/cfm/recordisplay.c

fm?deid=2835

Smoke-Free Homes Campaign:

http://www.epa.gov/smokefree/

Consumer and

commercial products

Many organic

chemicals and

metals, including

benzene, toluene,

xylenes, aldehydes

and ketones,

chlorinated solvents,

ethylene glycol and

glycol ethers,

phthalates, pesticides

N/A Voluntary programs to control

exposures/risks

Sources of VOCs indoors:

http://www.epa.gov/iaq/voc.html

Pesticides:

http://www.epa.gov/iaq/pesticid.html
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-36

Building materials Many, including

formaldehyde from

pressed wood

products; chemicals

(see consumer and

commercial

products) from

caulks and sealants,

paints and wall

coverings, floor

coverings, etc.; and

asbestos and lead in

older buildings

N/A Voluntary programs to control

exposures/risks

Formaldehyde: 

http://www.epa.gov/iaq/formalde.html

Asbestos:

http://www.epa.gov/asbestos/ashome.html

Lead:

http://www.epa.gov/iaq/lead.html

Natural Sources

Forest fires Various volatile and

semivolatile organic

compounds (e.g.,

dioxins, PAHs)

N/A No federal programs currently

exist

See tables 32-34 in:

http://www.epa.gov/ttn/chief/ap42/ch13/relat

ed/firerept.pdf. Also see the documentation

for the Preliminary 2002 National Emissions

Inventory (NEI), pages A58-A70: 

ftp://ftp.epa.gov/pub/EmisInventory/prelim2

002nei/nonpoint/documentation/2002prelim

neinonpt_032004.pdf, and and the 1999 final

NEI, (pages A56-A60: 

ftp://ftp.epa.gov/EmisInventory/finalnei99ve

r3/haps/documentation/nonpoint/nonpt99ver

3_aug2003.pdf

Radon radon N/A Voluntary programs to control

exposures/risks

Radon in indoor air:

http://www.epa.gov/radon
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-37

Other Sources

Long-range transport aldrin, chlordane,

DDT, dieldrin,

dioxins and furans,

endrin, mirex,

heptachlor, 

hexachlorobenzene,

mercury, PCBs,

toxaphene

N/A N/A Information on mercury as a global pollutant

can be found on the United Nations

Environment Programme website, which

also provides in-depth information and

assessment of the issue of global mercury

(see http://www.chem.unep.ch/mercury/). 

General information about the health and

environmental impacts of persistent organic

pollutants (POPs) can be found at

http://www.epa.gov/international/toxics/broc

hure.html. This site describes what actions

the United States and some other countries

have already taken to address these

pollutants, and to describe the

actions set into motion by the Stockholm

Convention on POPs to address

ths issue globally. More in-depth

information on global POPs can be found in 

The Foundation for Global Action on

Persistent Organic Pollutants: a United 

States Perspective, Office of Research and

Development, U.S. EPA, Research Triangle

Park, NC, EPA/600/P-01/003F, 2002

(http://cfpub.epa.gov/ncea/cfm/recordisplay.

cfm?deid=51746). General reference

websites with information on the issue of

long range transport are EPA's Great Lakes

National Program Office (GLNPO;

www.epa.gov/glnpo/), the Binational Toxics

Strategy (www.epa.gov/glnpo/bns/), and the

Artic Monitoring and Assessment

Programme (http://www.amap.no/).
Source Name(a) Typical Pollutants

Typical Industries

(SIC)

Regulatory and Control

Programs

References and Other Information

April 2004 Page E-38

(a) HAP Source Category names are followed by MACT source category codes used for source classification in the National Toxics Inventory (see

http://www.epa.gov/ttn/chief/codes/index.html#mact). Except for mobile and natural sources, and sources of indoor air toxics, the table does not include

sources of criteria pollutants and TRI chemicals that are not also MACT HAP sources.

(b) Very limited information is available about emissions and risks associated with the many non-HAP compounds used in solvent cleanings since the MACT

rule was promulgated. These compounds are not listed in the table.

(c)The estimate of air toxics emissions from halogenated solvent cleaning is from background analyses conducted for the MACT rule. The estimate is based

on estimates and assumptions about the national number of cleaning machines, the types of cleaning machines and processes in use, control equipment and

work practice standards in use before and after the MACT rule, solvents used and solvent use rates, and emissions factors for the various machine types and

control equipment combinations. A sample of MACT compliance reports collected from states and EPA regions for a residual risk assessment suggest that

(1) the population of cleaning machines estimated for the MACT rule may have been substantially overestimated and/or (2) many cleaning machines have

been removed from service or changed to solvents not covered by the MACT.
Appendix F Specific HAPs Included in the National

Emissions Inventory (NEI)
 
Appendix F. Specific HAPs Included in the NEI

EPAChemRegistryName NEI HAP Category NEI Pollutant Name 

1,1,1-Trichloroethane

Methyl Chloroform (1,1,1-Trichloroethane) Methyl Chloroform 

1,1,2,2-Tetrachloroethane 1,1,2,2-Tetrachloroethane 1,1,2,2-Tetrachloroethane 1,1,2-Trichloroethane 1,1,2-Trichloroethane 1,1,2-Trichloroethane 1,1'-Biphenyl, chloro derivs. Polychlorinated Biphenyls (Aroclors) Polychlorinated Biphenyls 

1,1-Dichloroethane

Ethylidene Dichloride (1,1-

Dichloroethane)

Ethylidene Dichloride (1,1-

Dichloroethane) 

1,1-Dichloroethylene

Vinylidene Chloride (1,1-

Dichloroethylene) Vinylidene Chloride 

1,1-Dimethylhydrazine 1,1-Dimethylhydrazine 1,1-Dimethyl Hydrazine 

1,2,3,4,6,7,8,9-Octachlorodibenzofuran Dioxins/Furans as 2,3,7,8-TCDD TEQs Octachlorodibenzofuran 1,2,3,4,6,7,8,9-Octachlorodibenzo-p-dioxin Dioxins/Furans as 2,3,7,8-TCDD TEQs Octachlorodibenzo-p-Dioxin 1,2,3,4,6,7,8-Heptachlorodibenzofuran Dioxins/Furans as 2,3,7,8-TCDD TEQs

1,2,3,4,6,7,8-Heptachlorodibenzofuran 

1,2,3,4,6,7,8-Heptachlorodibenzo-p-dioxin Dioxins/Furans as 2,3,7,8-TCDD TEQs

1,2,3,4,6,7,8-Heptachlorodibenzo-pDioxin 

1,2,3,4,7,8,9-Heptachlorodibenzofuran Dioxins/Furans as 2,3,7,8-TCDD TEQs

1,2,3,4,7,8,9-Heptachlorodibenzofuran 

1,2,3,4,7,8-Hexachlorodibenzofuran Dioxins/Furans as 2,3,7,8-TCDD TEQs

1,2,3,4,7,8-Hexachlorodibenzofuran 

1,2,3,4,7,8-Hexachlorodibenzo-p-dioxin Dioxins/Furans as 2,3,7,8-TCDD TEQs

1,2,3,4,7,8-Hexachlorodibenzo-pDioxin 

1,2,3,6,7,8-Hexachlorodibenzofuran Dioxins/Furans as 2,3,7,8-TCDD TEQs

1,2,3,6,7,8-Hexachlorodibenzofuran 

1,2,3,6,7,8-Hexachlorodibenzo-p-dioxin Dioxins/Furans as 2,3,7,8-TCDD TEQs

1,2,3,6,7,8-Hexachlorodibenzo-pDioxin 

1,2,3,7,8,9-Hexachlorodibenzofuran Dioxins/Furans as 2,3,7,8-TCDD TEQs

1,2,3,7,8,9-Hexachlorodibenzofuran 

1,2,3,7,8,9-Hexachlorodibenzo-p-dioxin Dioxins/Furans as 2,3,7,8-TCDD TEQs

1,2,3,7,8,9-Hexachlorodibenzo-pDioxin 

1,2,3,7,8-Pentachlorodibenzofuran Dioxins/Furans as 2,3,7,8-TCDD TEQs 1,2,3,7,8-Pentachlorodibenzofuran 1,2,3,7,8-Pentachlorodibenzo-p-dioxin Dioxins/Furans as 2,3,7,8-TCDD TEQs

1,2,3,7,8-Pentachlorodibenzo-pDioxin 

April 2004 
Appendix F. Specific HAPs Included in the NEI

EPAChemRegistryName NEI HAP Category NEI Pollutant Name 

1,2,4-Trichlorobenzene 1,2,4-Trichlorobenzene 1,2,4-Trichlorobenzene 1,2-Butylene oxide 1,2-Epoxybutane 1,2-Epoxybutane 

1,2-Dibromo-3-chloropropane 1,2-Dibromo-3-Chloropropane 1,2-Dibromo-3-Chloropropane 1,2-Dichloroethane

Ethylene Dichloride (1,2-

Dichloroethane) Ethylene Dichloride 

1,2-Dichloropropane

Propylene Dichloride (1,2-Dichloropropane) Propylene Dichloride 

1,2-Diphenylhydrazine 1,2-Diphenylhydrazine 1,2-Diphenylhydrazine 

1,3-Butadiene 1,3-Butadiene 1,3-Butadiene 1,3-Dichloropropene 1,3-Dichloropropene 1,3-Dichloropropene 1,3-Propane sultone 1,3-Propane Sultone 1,3-Propanesultone 1,4-Dichlorobenzene 1,4-Dichlorobenzene 1,4-Dichlorobenzene 1,4-Dioxane p-Dioxane p-Dioxane 1,6-Dinitropyrene Polycyclic Organic Matter 1,6-Dinitropyrene 1,8-Dinitropyrene Polycyclic Organic Matter 1,8-Dinitropyrene 12-Methylbenz[a]anthrancene Polycyclic Organic Matter 12-Methylbenz(a)Anthracene 1-Methylnaphthalene Polycyclic Organic Matter 1-Methylnaphthalene 1-Methylphenanthrene Polycyclic Organic Matter 1-Methylphenanthrene 1-Methylpyrene Polycyclic Organic Matter 1-Methylpyrene 1-Nitropyrene Polycyclic Organic Matter 1-Nitropyrene 

2,2,4-Trimethylpentane 2,2,4-Trimethylpentane 2,2,4-Trimethylpentane 2,3,4,6,7,8-Hexachlorodibenzofuran Dioxins/Furans as 2,3,7,8-TCDD TEQs

2,3,4,6,7,8-Hexachlorodibenzofuran 

2,3,4,7,8-Pentachlorodibenzofuran Dioxins/Furans as 2,3,7,8-TCDD TEQs 2,3,4,7,8-Pentachlorodibenzofuran 2,3,7,8-Tetrachlorodibenzofuran Dioxins/Furans as 2,3,7,8-TCDD TEQs 2,3,7,8-Tetrachlorodibenzofuran 2,3,7,8-Tetrachlorodibenzo-p-dioxin Dioxins/Furans as 2,3,7,8-TCDD TEQs

2,3,7,8-Tetrachlorodibenzo-pDioxin 

2,3,7,8-Tetrachlorodibenzo-p-dioxin, TEQ Dioxins/Furans as 2,3,7,8-TCDD TEQs 2,3,7,8-TCDD TEQ 2,4,5-Trichlorophenol 2,4,5-Trichlorophenol 2,4,5-Trichlorophenol 2,4,6-Trichlorophenol 2,4,6-Trichlorophenol 2,4,6-Trichlorophenol 2,4-D

2,4-D (2,4-Dichlorophenoxyacetic Acid)(Including Salts And Esters) 2,4-Dichlorophenoxy Acetic Acid 

2,4-Dinitrophenol 2,4-Dinitrophenol 2,4-Dinitrophenol 

April 2004 
Appendix F. Specific HAPs Included in the NEI

EPAChemRegistryName NEI HAP Category NEI Pollutant Name 

2,4-Dinitrotoluene 2,4-Dinitrotoluene 2,4-Dinitrotoluene 2,4-Toluenediamine Toluene-2,4-Diamine Toluene-2,4-Diamine 2-Acetylaminofluorene 2-Acetylaminofluorene 2-Acetylaminofluorene 2-Chloroacetophenone 2-Chloroacetophenone 2-Chloroacetophenone 2-Chloronaphthalene Polycyclic Organic Matter 2-Chloronaphthalene 

2-Ethoxyethanol Glycol Ethers Cellosolve Solvent 

2-Methoxyethanol Glycol Ethers Ethylene Glycol Methyl Ether 2-Methoxyethyl oleate Glycol Ethers Methoxyethyl Oleate 2-Methylnaphthalene Polycyclic Organic Matter 2-Methylnaphthalene 2-Nitrofluorene Polycyclic Organic Matter 2-Nitrofluorene 

2-Nitropropane 2-Nitropropane 2-Nitropropane 2-Propoxyethanol acetate Glycol Ethers 2-Propoxyethyl Acetate 

3,3'-Dichlorobenzidine 3,3'-Dichlorobenzidene 3,3'-Dichlorobenzidene 

3,3'-Dimethoxybenzidine 3,3'-Dimethoxybenzidine 3,3'-Dimethoxybenzidine 

3,3'-Dimethylbenzidine 3,3'-Dimethylbenzidine 3,3'-Dimethylbenzidine 3-Butoxy-1-propanol Glycol Ethers 3-Butoxy-1-Propanol 3-Methylcholanthrene Polycyclic Organic Matter 3-Methylcholanthrene 4,4'-Methylenebis(2-chloroaniline) 4,4'-Methylenebis(2-Chloroaniline) 4,4'-Methylenebis(2-Chloraniline) 4,4'-Methylenedi(phenyl isocyanate)

4,4'-Methylenediphenyl Diisocyanate (MDI)

4,4'-Methylenediphenyl Diisocyanate 

4,4'-Methylenedianiline 4,4'-Methylenedianiline 4,4'-Methylenedianiline 

4,6-Dinitro-o-cresol 4,6-Dinitro-o-Cresol (Including Salts) 4,6-Dinitro-o-Cresol 4-Aminobiphenyl 4-Aminobiphenyl 4-Aminobiphenyl 4-Dimethylaminoazobenzene 4-Dimethylaminoazobenzene 4-Dimethylaminoazobenzene 4-Nitrobiphenyl 4-Nitrobiphenyl 4-Nitrobiphenyl 4-Nitrophenol 4-Nitrophenol 4-Nitrophenol 5-Methylchrysene Polycyclic Organic Matter 5-Methylchrysene 6-Nitrochrysene Polycyclic Organic Matter 6-Nitrochrysene 

7,12-Dimethylbenz[a]anthracene Polycyclic Organic Matter 7,12-Dimethylbenz[a]Anthracene 

9-Methylanthracene Polycyclic Organic Matter 9-Methylbenz(a)Anthracene 

Acenaphthene Polycyclic Organic Matter as 15-PAH Acenaphthene Acenaphthylene Polycyclic Organic Matter as 15-PAH Acenaphthylene Acetaldehyde Acetaldehyde Acetaldehyde Acetamide Acetamide Acetamide Acetonitrile Acetonitrile Acetonitrile Acetophenone Acetophenone Acetophenone 

April 2004 
Appendix F. Specific HAPs Included in the NEI

EPAChemRegistryName NEI HAP Category NEI Pollutant Name 

Acrolein Acrolein Acrolein Acrylamide Acrylamide Acrylamide Acrylic acid Acrylic Acid Acrylic Acid Acrylonitrile Acrylonitrile Acrylonitrile Alkylated lead Lead Compounds Alkylated Lead Allyl chloride Allyl Chloride Allyl Chloride Ammonium dichromate (VI) Chromium Compounds Ammonium Dichromate Aniline Aniline Aniline Anthracene Polycyclic Organic Matter as 15-PAH Anthracene 

Antimonate(1-), hexafluoro-, sodium, (OC-6-11)- Antimony Compounds Sodium hexafluoroantimenate 

Antimony Antimony Compounds Antimony Antimony and compounds Antimony Compounds Antimony & Compounds Antimony oxide (unspecified) Antimony Compounds Antimony Oxide Antimony pentafluoride Antimony Compounds Antimony Pentafluoride Antimony trichloride Antimony Compounds Antimony Trichloride Antimony trioxide Antimony Compounds Antimony Trioxide Antimony trisulfide Antimony Compounds Antimony Trisulfide 

Arsenic

Arsenic Compounds(Inorganic Including 

Arsine) Arsenic 

Arsenic acid

Arsenic Compounds(Inorganic Including 

Arsine) Arsenic Acid 

Arsenic acid (H3AsO4), lead(2+) salt (1:1) Lead Compounds Lead Arsenate 

Arsenic compounds (inorganic including arsine)

Arsenic Compounds(Inorganic Including 

Arsine)

Arsenic & Compounds (Inorganic 

Including Arsine) 

Arsenic(III) trioxide

Arsenic Compounds(Inorganic Including 

Arsine) Arsenic Trioxide 

Arsenic(V) pentoxide

Arsenic Compounds(Inorganic Including 

Arsine) Arsenic Pentoxide 

Arsenous acid, triethyl ester

Arsenic Compounds(Inorganic Including 

Arsine) Arsenous Acid 

Arsine

Arsenic Compounds(Inorganic Including 

Arsine) Arsine 

Asbestos Asbestos Asbestos Aurate(1-), bis(cyano-.kappa.C)-, potassium Cyanide Compounds Gold (I) Potassium Cyanide Aurate(1-), bis(cyano-.kappa.C)-, potassium Cyanide Compounds Gold Potassium Cyanide 

April 2004 
Appendix F. Specific HAPs Included in the NEI

EPAChemRegistryName NEI HAP Category NEI Pollutant Name 

Aziridine Ethyleneimine (Aziridine) Ethyleneimine 

Benz[a]anthracene Polycyclic Organic Matter as 7-PAH Benz[a]Anthracene Benz[a]anthracene mixt. with chrysene Polycyclic Organic Matter as 7-PAH Benz(a)Anthracene/Chrysene 

Benzene

Benzene (Including Benzene From Gasoline) Benzene 

Benzene soluble organics Coke Oven Emissions Benzene Soluble Organics (BSO) Benzeneacetonitrile Cyanide Compounds Benzyl Cyanide Benzidine Benzidine Benzidine Benzo(b)fluoranthene Polycyclic Organic Matter as 7-PAH Benzo[b]Fluoranthene Benzo[a]fluoranthene Polycyclic Organic Matter Benzo(a)fluoranthene 

Benzo[a]pyrene Polycyclic Organic Matter as 7-PAH Benzo[a]Pyrene 

Benzo[b]fluoranthene mixt. with benzo[k]fluoranthenewith benzo[k]fluoranthene Polycyclic Organic Matter as 7-PAH Benzo[b+k]Fluoranthene Benzo[c]phenanthrene Polycyclic Organic Matter Benzo(c)phenanthrene 

Benzo[e]pyrene Polycyclic Organic Matter Benzo[e]Pyrene 

Benzo[ghi]fluoranthene Polycyclic Organic Matter Benzo(g,h,i)Fluoranthene Benzo[ghi]perylene Polycyclic Organic Matter as 15-PAH Benzo[g,h,i,]Perylene Benzo[j]fluoranthene Polycyclic Organic Matter B[j]Fluoranthen 

Benzo[k]fluoranthene Polycyclic Organic Matter as 7-PAH Benzo[k]Fluoranthene Benzofluoranthene Polycyclic Organic Matter as 7-PAH Benzofluoranthenes Benzotrichloride Benzotrichloride Benzotrichloride Benzyl chloride Benzyl Chloride Benzyl Chloride 

Beryllium Beryllium Compounds Beryllium Beryllium and compounds Beryllium Compounds Beryllium & Compounds Beryllium difluoride Beryllium Compounds Beryllium Fluoride Beryllium oxide Beryllium Compounds Beryllium Oxide beta-Propiolactone Beta-Propiolactone Beta-Propiolactone Biphenyl Biphenyl Biphenyl Bis(2-(2-butoxyethoxy)ethyl) phthalate Glycol Ethers

Di(Ethylene Glycol Monobutyl Ether) Phthalate 

Bis(2-chloroethyl) ether

Dichloroethyl Ether (Bis[2-

Chloroethyl]Ether) Dichloroethyl Ether 

Bis(chloromethyl) ether Bis(Chloromethyl) Ether Bis(Chloromethyl)Ether 

Borate(1-), tetrafluoro-, lead(2+) (2:1) Lead Compounds Lead Fluoroborate 

April 2004 
Appendix F. Specific HAPs Included in the NEI

EPAChemRegistryName NEI HAP Category NEI Pollutant Name 

C.I. Pigment Blue 28 Cobalt Compounds Cobalt Aluminate Cadmium Cadmium Compounds Cadmium Cadmium and compounds Cadmium Compounds Cadmium & Compounds Cadmium dichloride Cadmium Compounds Cadmium Chloride Cadmium iodide Cadmium Compounds Cadmium Iodide Cadmium nitrate Cadmium Compounds Cadmium Nitrate Cadmium oxide Cadmium Compounds Cadmium Oxide Cadmium sulfide Cadmium Compounds Cadmium Sulfide Captan Captan Captan Carbaryl Carbaryl Carbaryl Carbon disulfide Carbon Disulfide Carbon Disulfide Carbon tetrachloride Carbon Tetrachloride Carbon Tetrachloride Carbonic acid, lead(2+) salt (1:1) Lead Compounds Lead Carbonate Carbonic acid, nickel(2+) salt (1:1) Nickel Compounds Nickel Carbonate Carbonyl sulfide Carbonyl Sulfide Carbonyl Sulfide 

Catechol Catechol Catechol Ceramic fibers, man-made Fine Mineral Fibers Ceramic Fibers (Man-Made) Chloramben Chloramben Chloramben Chlordane Chlordane Chlordane Chlorinated dibenzo-p-dioxins Dioxins/Furans (total, non TEQ)

Dioxins, Total, w/o Individ. Isomers Reported {PCDDs} 

Chlorinated dibenzo-p-dioxins Dioxins/Furans (total, non TEQ)

Polychlorinated Dibenzo-p-Dioxins, Total 

Chlorine Chlorine Chlorine Chloroacetic acid Chloroacetic Acid Chloroacetic Acid Chlorobenzene Chlorobenzene Chlorobenzene Chlorobenzilate Chlorobenzilate Chlorobenzilate Chlorodibenzofurans Dioxins/Furans (total, non TEQ)

Dibenzofurans (Chlorinated) {PCDFs} 

Chlorodibenzofurans Dioxins/Furans (total, non TEQ)

Polychlorinated Dibenzofurans, Total 

Chloroethane Ethyl Chloride Ethyl Chloride Chloroform Chloroform Chloroform Chloromethane Methyl Chloride (Chloromethane) Methyl Chloride Chloromethyl methyl ether Chloromethyl Methyl Ether Chloromethyl Methyl Ether Chloroprene Chloroprene Chloroprene 

April 2004 
Appendix F. Specific HAPs Included in the NEI

EPAChemRegistryName NEI HAP Category NEI Pollutant Name 

Chlorpyrifos Phosphorus Compounds Phosphorothioic Acid Chromic acid (H2CrO4), barium salt (1:1) Chromium Compounds Barium Chromate Chromic acid (H2CrO4), calcium salt (1:1) Chromium Compounds Calcium Chromate Chromic acid (H2CrO4), lead(2+) salt (1:1) Lead Compounds Lead Chromate Chromic acid (H2CrO4), strontium salt (1:1) Chromium Compounds Strontium Chromate Chromic acid, mixt. with sulfuric acid Chromium Compounds Chromic Sulfuric Acid Chromic(VI) acid Chromium Compounds Chromic Acid Chromic(VI) acid Chromium Compounds Chromic Acid (VI) Chromium Chromium Compounds Chromium Chromium and compounds Chromium Compounds Chromium & Compounds Chromium chloride, hexahydrate Chromium Compounds Chromium Chloride Chromium difluoride dioxide Chromium Compounds Chromyl Fluoride Chromium oxide (CrO2) Chromium Compounds Chromium Dioxide Chromium zinc oxide (Cr2ZnO4) Chromium Compounds Chromium Zinc Oxide Chromium zinc oxide (unspecified) Chromium Compounds Zinc Chromite Chromium(III) Chromium Compounds Chromium III Chromium(III) acetylacetonate Chromium Compounds Chromium (III)-AA Chromium(III) hydroxide Chromium Compounds Chromium Hydroxide Chromium(III) oxide Chromium Compounds Chromic Oxide Chromium(VI) Chromium Compounds Chromium (VI) Chromium(VI) dioxychloride Chromium Compounds Chromyl Chloride Chromium(VI) trioxide Chromium Compounds Chromium Trioxide Chrysene Polycyclic Organic Matter as 7-PAH Chrysene Coal tar Coke Oven Emissions Coal Tar 

Cobalt Cobalt Compounds Cobalt 

Cobalt and compounds Cobalt Compounds Cobalt & Compounds Cobalt hydrocarbonyl Cobalt Compounds Cobalt Hydrocarbonyl Cobalt naphthenate Cobalt Compounds Cobalt Naphtha Cobalt tetraoxide Cobalt Compounds Cobalt Oxide (II,III) Cobalt(II) oxide Cobalt Compounds Cobalt Oxide Cobalt(II) sulfide Cobalt Compounds Cobalt Sulfide Cobalt, tetracarbonylhydro- Cobalt Compounds Cobalt Carbonate 

Coke oven emissions Coke Oven Emissions Coke Oven Emissions Copper(I) cyanide Cyanide Compounds Copper Cyanide 

Cresol Cresol/Cresylic Acid (Mixed Isomers) Cresol 

April 2004 
Appendix F. Specific HAPs Included in the NEI

EPAChemRegistryName NEI HAP Category NEI Pollutant Name 

Cresol Cresol/Cresylic Acid (Mixed Isomers)

Cresols (Includes o, m, & p)/Cresylic Acids 

Cumene Cumene Cumene Cyanamide, calcium salt (1:1) Calcium Cyanamide Calcium Cyanamide Cyanide Cyanide Compounds Cyanide 

Cyanide and compounds Cyanide Compounds Cyanide & Compounds Cyclonaphthenes Polycyclic Organic Matter Naphthenes (Cyclo) 

Di(2-ethylhexyl) phthalate Bis(2-Ethylhexyl)Phthalate (Dehp) Bis(2-Ethylhexyl)Phthalate 

Diazomethane Diazomethane Diazomethane Dibenz[a,h]anthracene Polycyclic Organic Matter as 7-PAH Dibenzo[a,h]Anthracene Dibenz[a,j]acridine Polycyclic Organic Matter Dibenzo[a,j]Acridine 

Dibenzo[a,e]pyrene Polycyclic Organic Matter Dibenzo[a,e]Pyrene 

Dibenzo[a,h]pyrene Polycyclic Organic Matter Dibenzo[a,h]Pyrene Dibenzo[a,i]pyrene Polycyclic Organic Matter Dibenzo[a,i]Pyrene Dibenzo[a,l]pyrene Polycyclic Organic Matter Dibenzo[a,l]Pyrene Dibenzofuran Dibenzofuran Dibenzofuran Dibenzo-p-dioxin Dioxins/Furans (total, non TEQ) Dibenzo-p-Dioxin Dibutyl phthalate Dibutyl Phthalate Dibutyl Phthalate Dichlorvos Dichlorvos Dichlorvos Diethanolamine Diethanolamine Diethanolamine Diethyl sulfate Diethyl Sulfate Diethyl Sulfate Diethylene glycol dibenzoate Glycol Ethers Diethylene Glycol Dibenzoate Diethylene glycol diethyl ether Glycol Ethers Diethylene glycol diethyl ether Diethylene glycol diglycidyl ether Glycol Ethers Diethylene Glycol Diglycidyl Ether Diethylene glycol dimethyl ether Glycol Ethers Diethylene Glycol Dimethyl Ether Diethylene glycol dinitrate Glycol Ethers Diethylene Glycol Dinitrate Diethylene glycol ethyl methyl ether Glycol Ethers

Diethylene Glycol Ethyl Methyl Ether 

Diethylene glycol mono-2-cyanoethyl ether Glycol Ethers

Diethylene Glycol Mono-2-

Cyanoethyl Ether 

Diethylene glycol mono-2-methylpentyl ether Glycol Ethers

Diethyleneglycol-Mono-2-MethylPentyl Ether 

Diethylene glycol monobutyl ether Glycol Ethers Diethylene Glycol Monobutyl Ether Diethylene glycol monobutyl ether acetate Glycol Ethers Butyl Carbitol Acetate 

April 2004 
Appendix F. Specific HAPs Included in the NEI

EPAChemRegistryName NEI HAP Category NEI Pollutant Name 

Diethylene glycol monoethyl ether Glycol Ethers Diethylene Glycol Monoethyl Ether Diethylene glycol monoethyl ether acetate Glycol Ethers Carbitol Acetate 

Diethylene glycol monohexyl ether Glycol Ethers N-Hexyl Carbitol Diethylene glycol monoisobutyl ether Glycol Ethers

Diethylene Glycol Monoisobutyl Ether 

Diethylene glycol monomethyl ether Glycol Ethers

Diethylene Glycol Monomethyl Ether 

Diethylene glycol monovinyl ether Glycol Ethers Diethylene Glycol Monovinyl Ether Dimethyl mercury Mercury Compounds Methyl Mercury 

Dimethyl phthalate Dimethyl Phthalate Dimethyl Phthalate Dimethyl sulfate Dimethyl Sulfate Dimethyl Sulfate Dimethylcarbamoyl chloride Dimethylcarbamoyl Chloride Dimethylcarbamoyl Chloride Dioxins Dioxins/Furans (total, non TEQ) Dioxins Epichlorohydrin

Epichlorohydrin (1-Chloro-2,3-

Epoxypropane) 1-Chloro-2,3-Epoxypropane 

Ethanol, 2-(phenylmethoxy)- Glycol Ethers Ethylene Glycol Monobenzyl Ether Ethene, [2-(2-ethoxyethoxy)ethoxy]- Glycol Ethers Diethylene Glycol Ethylvinyl Ether Ethene, 1,1'-[oxybis(2,1-ethanediyloxy)]bis- Glycol Ethers Diethylene Glycol Divinyl Ether 

Ethyl acrylate Ethyl Acrylate Ethyl Acrylate Ethylbenzene Ethylbenzene Ethyl Benzene Ethylene dibromide Ethylene Dibromide (Dibromoethane) Ethylene Dibromide 

Ethylene glycol Ethylene Glycol Ethylene Glycol 

Ethylene glycol bis(2,3-epoxy-2-methylpropyl) ether Glycol Ethers

Ethylene Glycol Bis(2,3-Epoxy-2-

Methylpropyl) Ether 

Ethylene glycol diallyl ether Glycol Ethers Ethylene Glycol Diallyl Ether 

Ethylene glycol diethyl ether Glycol Ethers Ethylene Glycol Diethyl Ether Ethylene glycol dimethyl ether Glycol Ethers 1,2-Dimethoxyethane 

Ethylene glycol mono-2,6,8-trimethyl-4-nonyl ether Glycol Ethers

Ethyleneglycolmono-2,6,8-

Trimethyl-4-Nonyl Ether 

Ethylene glycol mono-2-methylpentyl ether Glycol Ethers

Ethyleneglycol Mono-2-Methylpentyl Ether 

Ethylene glycol monobutyl ether Glycol Ethers Butyl Cellosolve 

April 2004 
Appendix F. Specific HAPs Included in the NEI

EPAChemRegistryName NEI HAP Category NEI Pollutant Name 

Ethylene glycol monobutyl ether acetate Glycol Ethers 2-Butoxyethyl Acetate 

Ethylene glycol monoethyl ether acetate Glycol Ethers Cellosolve Acetate 

Ethylene glycol monohexyl ether Glycol Ethers 2-(Hexyloxy)Ethanol Ethylene glycol monoisobutyl ether Glycol Ethers Isobutyl Cellosolve 

Ethylene glycol monomethyl ether acetate Glycol Ethers

Ethylene Glycol Monomethyl Ether Acetate 

Ethylene glycol monomethyl ether acrylate Glycol Ethers Methyl Cellosolve Acrylate Ethylene glycol monophenyl ether Glycol Ethers Phenyl Cellosolve Ethylene glycol monophenyl ether propionate Glycol Ethers

Ethyleneglycol Monophenyl Ether Propionate 

Ethylene glycol monopropyl ether Glycol Ethers Propyl Cellosolve Ethylene glycol mono-sec-butyl ether Glycol Ethers

Ethylene Glycol Mono-Sec-Butyl Ether 

Ethylene glycol monovinyl ether Glycol Ethers Ethylene Glycol Monovinyl Ether Ethylene oxide Ethylene Oxide Ethylene Oxide Ethylene thiourea Ethylene Thiourea Ethylene Thiourea Ethylenebis(oxyethylenenitrilo)tetraacetic acid Glycol Ethers

(Ethylenebis(Oxyethylenenitrilo)) Tetraacetic Acid 

Extractable organic matter (EOM) Polycyclic Organic Matter Extractable Organic Matter (EOM) Fine mineral fibers Fine Mineral Fibers Fine Mineral Fibers Fine mineral fibers Fine Mineral Fibers Glasswool (Man-Made Fibers) Fine mineral fibers Fine Mineral Fibers Slagwool (Man-Made Fibers) Fine mineral fibers Fine Mineral Fibers Rockwool (Man-Made Fibers) Fluoranthene Polycyclic Organic Matter as 15-PAH Fluoranthene Fluorene Polycyclic Organic Matter as 15-PAH Fluorene Formaldehyde Formaldehyde Formaldehyde Glycol ethers -- CAA 112B Glycol Ethers Glycol Ethers Gold cyanide Cyanide Compounds Gold Cyanide Heptachlor Heptachlor Heptachlor Heptachlorodibenzofuran Dioxins/Furans (total, non TEQ) Total Heptachlorodibenzofuran Heptachlorodibenzo-p-dioxin Dioxins/Furans (total, non TEQ) Total Heptachlorodibenzo-p-Dioxin Hexachlorobenzene Hexachlorobenzene Hexachlorobenzene Hexachlorobutadiene Hexachlorobutadiene Hexachlorobutadiene Hexachlorocyclopentadiene Hexachlorocyclopentadiene Hexachlorocyclopentadiene 

April 2004 
Appendix F. Specific HAPs Included in the NEI

EPAChemRegistryName NEI HAP Category NEI Pollutant Name 

Hexachlorodibenzofuran Dioxins/Furans (total, non TEQ) Total Hexachlorodibenzofuran Hexachlorodibenzo-p-dioxin Dioxins/Furans (total, non TEQ) Hexachlorodibenzo-p-Dioxin Hexachlorodibenzo-p-dioxin Dioxins/Furans (total, non TEQ)

Hexachlorodibenzo-p-Dioxins, Total 

Hexachloroethane Hexachloroethane Hexachloroethane Hexamethylene-1,6-diisocyanate Hexamethylene Diisocyanate Hexamethylene Diisocyanate 

Hexamethylphosphoramide Hexamethylphosphoramide Hexamethylphosphoramide Hexane Hexane Hexane Hexanoic acid, 2-ethyl-, cobalt(2+) salt Cobalt Compounds Cobalt 2-ethylhexanoate Hydrazine Hydrazine Hydrazine Hydrochloric acid

Hydrochloric Acid (Hydrogen Chloride [Gas Only]) Hydrochloric Acid 

Hydrofluoric acid Hydrogen Fluoride (Hydrofluoric Acid) Hydrogen Fluoride Hydrogen cyanide Cyanide Compounds Hydrogen Cyanide Hydroquinone Hydroquinone Hydroquinone Indeno[1,2,3-cd]pyrene Polycyclic Organic Matter as 7-PAH Indeno[1,2,3-c,d]Pyrene Iodine-131 Radionuclides (Including Radon) Iodine-131 Isobutyronitrile Cyanide Compounds 2-Methyl-Propanenitrile Isophorone Isophorone Isophorone Lead Lead Compounds Lead Lead acetate Lead Compounds Lead Subacetate Lead and compounds Lead Compounds Lead & Compounds Lead and compounds (other than inorganic) Lead Compounds

Lead Compounds (Other Than Inorganic) 

Lead and compounds, inorganic Lead Compounds Lead Compounds (Inorganic) Lead arsenite (Pb(AsO2)2) Lead Compounds Lead Arsenite Lead chromate(VI) oxide Lead Compounds Lead Chromate Oxide Lead dioxide Lead Compounds Lead Dioxide Lead dioxide Lead Compounds Lead Dioxide, Unknown CAS # Lead monoxide Lead Compounds Lead (II) Oxide Lead naphthenate Lead Compounds Lead Naphthenate Lead nitrate (Pb(NO3)2) Lead Compounds Lead Nitrate Lead oxide Lead Compounds Lead Oxide Lead stearate Lead Compounds Lead Stearate Lead tetraoxide Lead Compounds Lead (II, IV) Oxide Lead titanium oxide (PbTiO3) Lead Compounds Lead Titanate 

April 2004 
Appendix F. Specific HAPs Included in the NEI

EPAChemRegistryName NEI HAP Category NEI Pollutant Name 

Lead titanium zirconium oxide (Pb(Ti,Zr)O3) Lead Compounds Lead Titanate Zircon Lead(II) acetate Lead Compounds Lead Acetate Lindane

1,2,3,4,5,6-Hexachlorocyclyhexane (All Stereo Isomers, Including Lindane) 1,2,3,4,5,6-Hexachlorocyclyhexane 

Lithium chromate Chromium Compounds Lithium Chromate Maleic anhydride Maleic Anhydride Maleic Anhydride 

Manganese Manganese Compounds Manganese Manganese and compounds Manganese Compounds Manganese & Compounds Manganese dioxide Manganese Compounds Manganese Dioxide Manganese naphthenate Manganese Compounds Manganese Napthenate Manganese tallate Manganese Compounds Manganese Tallate Manganese tetraoxide Manganese Compounds Manganese Tetroxide Manganese(II) hypophosphite monohydrate Manganese Compounds Manganesehypophosphi 

Manganese(III) oxide Manganese Compounds Manganese Trioxide m-Cresol Cresol/Cresylic Acid (Mixed Isomers) m-Cresol Mercuric chloride Mercury Compounds Mercuric Chloride Mercury Mercury Compounds Elemental Gaseous Mercury 

Mercury Mercury Compounds Mercury Mercury and compounds Mercury Compounds Mercury & Compounds Mercury, divalent Mercury Compounds Gaseous Divalent Mercury Mercury, divalent Mercury Compounds Particulate Divalent Mercury Methanol Methanol Methanol Methoxychlor Methoxychlor Methoxychlor Methyl bromide Methyl Bromide (Bromomethane) Methyl Bromide Methyl cellosolve acetyl ricinoleate Glycol Ethers Methyl Cellosolve Acetylricinoleate Methyl ethyl ketone Methyl Ethyl Ketone (2-Butanone) Methyl Ethyl Ketone Methyl hydrazine Methylhydrazine Methylhydrazine Methyl iodide Methyl Iodide (Iodomethane) Methyl Iodide Methyl isobutyl ketone Methyl Isobutyl Ketone (Hexone) Methyl Isobutyl Ketone Methyl isocyanate Methyl Isocyanate Methyl Isocyanate Methyl methacrylate Methyl Methacrylate Methyl Methacrylate Methyl tert-butyl ether Methyl Tert-Butyl Ether Methyl Tert-Butyl Ether Methylanthracene Polycyclic Organic Matter Methylanthracene Methylbenzopyrene Polycyclic Organic Matter Methylbenzopyrenes 

April 2004 
Appendix F. Specific HAPs Included in the NEI

EPAChemRegistryName NEI HAP Category NEI Pollutant Name 

Methylchrysene Polycyclic Organic Matter Methylchrysene 

Methylene chloride Methylene Chloride (Dichloromethane) Methylene Chloride Methylene chloride soluble organics Coke Oven Emissions

Methylene Chloride Soluble Organics (MCSO) 

Methylmercury Mercury Compounds Mercury (Organic) 

m-Xylene Xylenes (Mixed Isomers) m-Xylene N,N-Dimethylaniline N,N-Dimethylaniline N,N-Dimethylaniline N,N-Dimethylformamide N,N-Dimethylformamide N,N-Dimethylformamide Naphthalene Naphthalene Naphthalene Neodecanoic acid, lead salt Lead Compounds Lead Neodecanoate Nickel Nickel Compounds Nickel Nickel and compounds Nickel Compounds Nickel & Compounds Nickel carbide Nickel Compounds Nickel Carbide Nickel carbonyl Nickel Compounds Nickel Carbonyl Nickel diacetate tetrahydrate Nickel Compounds Nickel Diacetate TET Nickel hydroxide (Ni(OH)2) Nickel Compounds Nickel Hydroxide Nickel refinery dust Nickel Compounds Nickel Refinery Dust 

Nickel subsulfide Nickel Compounds Nickel Subsulfide Nickel(II) acetate Nickel Compounds Nickel Acetate Nickel(II) bromide Nickel Compounds Nickel Bromide Nickel(II) chloride Nickel Compounds Nickel Chloride Nickel(II) nitrate Nickel Compounds Nickel Nitrate Nickel(II) oxide Nickel Compounds Nickel Oxide Nickel(III) oxide Nickel Compounds Nickel Peroxide Nickel-59 Nickel Compounds Nickel (NI 059) Nickelate(2-), tetrakis(cyano-.kappa.C)-, dipotassium, (SP-4-1)- Cyanide Compounds Potass Nickel Cyanid Nickelocene Nickel Compounds Nickelocene Nitric acid, manganese(2+) salt Manganese Compounds Manganese Nitrate Nitrobenzene Nitrobenzene Nitrobenzene N-Nitrosodimethylamine N-Nitrosodimethylamine N-Nitrosodimethylamine N-Nitrosomorpholine N-Nitrosomorpholine N-Nitrosomorpholine N-Nitroso-N-methylurea N-Nitroso-N-Methylurea N-Nitroso-N-Methylurea o-Anisidine o-Anisidine o-Anisidine o-Cresol Cresol/Cresylic Acid (Mixed Isomers) o-Cresol 

April 2004 
Appendix F. Specific HAPs Included in the NEI

EPAChemRegistryName NEI HAP Category NEI Pollutant Name 

o-Toluidine o-Toluidine o-Toluidine o-Xylene Xylenes (Mixed Isomers) o-Xylene p,p'-DDE

Dde (1,1-Dichloro-2,2-Bis(pChlorophenyl) Ethylene) Dde (1,1-Dichloro-2,2-Bis(p- Chlorophenyl) Ethylene) 

Parathion Parathion Parathion p-Cresol Cresol/Cresylic Acid (Mixed Isomers) p-Cresol Pentachlorodibenzofuran Dioxins/Furans (total, non TEQ) Total Pentachlorodibenzofuran Pentachlorodibenzo-p-dioxin Dioxins/Furans (total, non TEQ) Total Pentachlorodibenzo-p-Dioxin Pentachloronitrobenzene

Pentachloronitrobenzene (Quintobenzene) Pentachloronitrobenzene 

Pentachlorophenol Pentachlorophenol Pentachlorophenol Perylene Polycyclic Organic Matter Perylene 

Phenanthrene Polycyclic Organic Matter as 15-PAH Phenanthrene Phenol Phenol Phenol Phenylmercury acetate Mercury Compounds Mercury Acetato Phen 

Phosgene Phosgene Phosgene Phosphine Phosphine Phosphine Phosphoric acid Phosphorus Compounds Phosphoric Acid Phosphoric acid, lead(2+) salt (2:3) Lead Compounds Lead Phosphate Phosphoric acid, monoammonium monosodium salt Phosphorus Compounds Phosphorous Salt Phosphoric acid, reaction products with aluminum hydroxide and chromium oxide (CrO3) Phosphorus Compounds Phosphoric Acid,Rx P Phosphoric acid, zinc salt (2:3) Phosphorus Compounds Zinc Phosphate Phosphorous acid Phosphorus Compounds Phosphorous Acid Phosphorus Phosphorus Compounds Phosphorus Phosphorus and compounds Phosphorus Compounds Phosphorus & Compounds Phosphorus nitride (P3N5) Phosphorus Compounds Phosphorous Nitride Phosphorus oxychloride Phosphorus Compounds Phosphorus Oxychloride Phosphorus pentasulfide Phosphorus Compounds Phosphorus Pentasulfide Phosphorus pentoxide Phosphorus Compounds Phosphorus Pentoxide Phosphorus trichloride Phosphorus Compounds Phosphorus Trichloride Phosphorus trioxide Phosphorus Compounds Phosphorus Trioxide Phthalic anhydride Phthalic Anhydride Phthalic Anhydride 

April 2004 
Appendix F. Specific HAPs Included in the NEI

EPAChemRegistryName NEI HAP Category NEI Pollutant Name 

Polycyclic aromatic hydrocarbons Polycyclic Organic Matter as 7-PAH PAH, Total 

Polycyclic aromatic hydrocarbons - 16-PAH Polycyclic Organic Matter 16-PAH 

Polycyclic aromatic hydrocarbons - 7-PAH Polycyclic Organic Matter as 7-PAH 7-PAH Polycyclic organic matter - including 15-PAH Polycyclic Organic Matter as 7-PAH Polycyclic Organic Matter 

Potassium chromate (VI) Chromium Compounds Potassium Chromate Potassium cyanide Cyanide Compounds Potassium Cyanide Potassium dichromate Chromium Compounds Potassium Dichromate Potassium ferrocyanide Cyanide Compounds Potassium Ferrocyani Potassium permanganate Manganese Compounds Potassium permanganate Potassium zinc chromate hydroxide (KZn2(CrO4)2(OH)) Chromium Compounds Zinc Potassium Chromate p-Phenylenediamine p-Phenylenediamine p-Phenylenediamine Propionaldehyde Propionaldehyde Propionaldehyde Propoxur Propoxur (Baygon) Propoxur Propylene glycol monoisobutyl ether Glycol Ethers 1-Isobutoxy-2-Propanol 

Propylene oxide Propylene Oxide Propylene Oxide 

Propyleneimine 1,2-Propylenimine (2-Methylaziridine) 1,2-Propylenimine 

p-Xylene Xylenes (Mixed Isomers) p-Xylene Pyrene Polycyclic Organic Matter as 15-PAH Pyrene Quinoline Quinoline Quinoline Quinone Quinone (p-Benzoquinone) Quinone Radionuclides (including radon) Radionuclides (Including Radon) Radionuclides (Including Radon) Radionuclides (including radon) Radionuclides (Including Radon) Radionuclides Radon and its decay products Radionuclides (Including Radon) Radon And Its Decay Products Selenious acid (H2SeO3) Selenium Compounds Selenous Acid Selenium Selenium Compounds Selenium Selenium and compounds Selenium Compounds Selenium & Compounds Selenium dioxide Selenium Compounds Selenium Dioxide Selenium disulfide Selenium Compounds Selenium Disulfide Selenium hexafluoride Selenium Compounds Selenium Hexafluoride Selenium monosulfide Selenium Compounds Selenium Monosulfide Selenium oxide Selenium Compounds Selenium Oxide Silver cyanide Cyanide Compounds Silver Cyanide 

Sodium chromate (VI) Chromium Compounds Sodium Chromate Sodium chromate(VI), tetrahydrate Chromium Compounds Sodium Chromate(VI) Sodium cyanide Cyanide Compounds Sodium Cyanide 

April 2004 
Appendix F. Specific HAPs Included in the NEI

EPAChemRegistryName NEI HAP Category NEI Pollutant Name 

Sodium dichromate Chromium Compounds Sodium Dichromate Sodium permanganate Manganese Compounds Permanganic acid Styrene Styrene Styrene Styrene oxide Styrene Oxide Styrene Oxide 

Sulfamic acid, nickel(2+) salt (2:1) Nickel Compounds Nickel Sulfamate Sulfuric acid, beryllium salt (1:1) Beryllium Compounds Beryllium Sulfate Sulfuric acid, cadmium salt (1:1) Cadmium Compounds Cadmium Sulfate Sulfuric acid, chromium(3+) salt (3:2) Chromium Compounds Chromic Sulfate Sulfuric acid, cobalt(2+) salt (1:1) Cobalt Compounds Cobalt Sulfate Sulfuric acid, lead(2+) salt (1:1) Lead Compounds Lead Sulfate Sulfuric acid, manganese(2+) salt (1:1) Manganese Compounds Manganese Sulfate Sulfuric acid, nickel(2+) salt (1:1) Nickel Compounds Nickel Sulfate Sulfuric acid, nickel(2+) salt (1:1), hexahydrate Nickel Compounds Nickel (II) Sulfate Hexahydrate Tetrachlorodibenzofuran Dioxins/Furans (total, non TEQ) Total Tetrachlorodibenzofuran Tetrachlorodibenzo-p-dioxin Dioxins/Furans (total, non TEQ) Total Tetrachlorodibenzo-p-Dioxin Tetrachloroethylene Tetrachloroethylene (Perchloroethylene) Tetrachloroethylene Tetraethyl lead Lead Compounds Tetraethyl Lead Titanium tetrachloride Titanium Tetrachloride Titanium Tetrachloride Toluene Toluene Toluene Toluene-2,4-diisocyanate 2,4-Toluene Diisocyanate 2,4-Toluene Diisocyanate Toxaphene Toxaphene (Chlorinated Camphene) Toxaphene Tribromomethane Bromoform Bromoform Trichloroethylene Trichloroethylene Trichloroethylene Triethylamine Triethylamine Triethylamine Triethylene glycol Glycol Ethers Triethylene glycol 

Triethylene glycol dimethyl ether Glycol Ethers Triethylene Glycol Dimethyl Ether Triethylene glycol monobutyl ether Glycol Ethers Triglycol Monobutyl Ether Triethylene glycol monoethyl ether Glycol Ethers Ethoxytriglycol Triethylene glycol monomethyl ether Glycol Ethers Methoxytriglycol Trifluralin Trifluralin Trifluralin Trimethylene glycol monomethyl ether Glycol Ethers 3-Methoxy-1-Propanol 

Tri-o-cresyl phosphate Phosphorus Compounds Triorthocresyl Phosphate Triphenyl phosphate Phosphorus Compounds Triphenyl Phosphate 

April 2004 
Appendix F. Specific HAPs Included in the NEI

EPAChemRegistryName NEI HAP Category NEI Pollutant Name 

Triphenyl phosphite Phosphorus Compounds Triphenyl Phosphite 

Uranium-238 Radionuclides (Including Radon) Uranium Urethane

Ethyl Carbamate (Urethane) Chloride (Chloroethane) Ethyl Carbamate Chloride 

Vinyl acetate Vinyl Acetate Vinyl Acetate Vinyl bromide Vinyl Bromide Vinyl Bromide Vinyl chloride Vinyl Chloride Vinyl Chloride Xylene Xylenes (Mixed Isomers)

Xylenes (Mixture of o, m, and p Isomers) 

Zinc chromate Chromium Compounds Zinc Chromate Zinc chromate Chromium Compounds Zinc Chromate Zinc cyanide Cyanide Compounds Zinc Cyanide 

Field Definitions:• “EPAChemRegistryName” (EPA Chemical Registry Name) - the name EPA has selected as the name to be commonly used by

EPA in referring to a chemical substance

• “NEI HAP Category” - Grouping of related NEI pollutants• “NEI Pollutant Name” - HAP name for NEI pollutant• “CASRN” (Chemical Abstracts Service Registry Number)- the unique number assigned by Chemical Abstracts Service (CAS) to a chemical substanceTable from:EPA. 2003. 1999 NEI Final Version 3 for Hazardous Air Pollutants Point, non point, and mobile sources. Documentation for the1999 NEI Final Version 3 for Hazardous Air Pollutants. HAPs list with chemical ID standard fields - August 2003 OAQPS.Available at http://www.epa.gov/ttn/chief/net/1999inventory.html#final3hapsField Definitions from:

1999 NEI Final Version 3 for Hazardous Air Pollutants Point, non point, and mobile sources (September 2003). Documentation for

the 1999 NEI Final Version 3 for Hazardous Air Pollutants.Readme file for HAPs list with chemical ID standard fields - August2003. Available at http://www.epa.gov/ttn/chief/net/1999inventory.html#final3hapsField Definitions:

April 2004 
Appendix G Atmospheric and Meteorological

Concepts Relevant to Dispersal,

Transport, and Fate of Air Toxics

Table of Contents

1.0 Structure and Composition of the Atmosphere ............ ............ ............ ... 1

2.0 Atmospheric Energy ............ ............ ............ ............ ........... 1

2.1 Solar Radiation and Differential Heating ............ ............ ............ 1

2.2 Effects of Topography ............ ............ ............ ............ ... 3

3.0 Atmospheric Motions ............ ............ ............ ............ .......... 4

3.1 Horizontal Air Motions ............ ............ ............ ............ . . 4

3.2 Vertical Air Motions ............ ............ ............ ............ .... 5

 4.0 Meteorological Data ............ ............ ............ ............ ........... 8

4.1 Wind Speed and Direction ............ ............ ............ ............ 8

4.2 Other Important Meteorological Data ............ ............ ............ ... 9

4.3 Sources of Meteorological Data ............ ............ ............ ...... 11

References ............ ............ ............ ............ ............ ............ 12

April 2004 Page G-1

This Appendix defines and discusses atmospheric and meteorological concepts relevant to

modeling dispersion, transport, and fate of air toxics. In addition, this appendix provides

information on sources of meteorological data that can be used for air toxics modeling. Much of

this information was obtained from EPA’s primer on air pollution meteorology (see

http://www.epa.gov/oar/oaqps/eog/catalog/si409.html). Basic textbooks on meteorology provide

more detailed discussions of the material summarized in this Appendix.

1.0 Structure and Composition of the Atmosphere

The atmosphere consists of mixture of about 78 percent nitrogen, 21 percent oxygen and one

percent argon up to about 90 km. Within this region trace gases include carbon dioxide, neon,

helium, and water vapor. Although the water vapor content of the air is fairly small it is highly

variable. Water vapor absorbs six times more radiation energy than any other atmospheric

constituent and is therefore a very important component of the atmosphere. Similarly, carbon

dioxide is highly variable and is important gas because it absorbs and re-radiates back some of

the infrared radiation emitted by the earth. 

The atmosphere has been divided into four regions (Exhibit 1) based on temperature changes

with height: the troposphere, stratosphere, mesosphere, and ionosphere. The troposphere

accounts for about three quarters of the mass of the atmosphere and contains nearly all of the

water in the atmosphere (in the forms of vapor, clouds, and precipitation). The depth of the

troposphere is on average about 16.5 km (54,000 ft) over the equator and about 8.5 km (28,000

ft) over the poles. The troposphere also tends to be thicker in summer (when the air is warmer)

than in the winter. The depth of the troposphere changes constantly due to changes in

atmospheric temperature. The troposphere is the most important layer of the atmosphere with

respect to air toxics, because this is the region in which most of the air toxics are released. Of the

other regions of the atmosphere only the stratosphere has a direct role for some air toxics. Some

air toxic emissions can be circulated into the lower stratosphere via weather system or directly

emitted from aircraft or volcanic eruption. Once air toxics reach the stratosphere they maybe

transported very long distances.

2.0 Atmospheric Energy 

The troposphere is the most variable layer of the atmosphere and is the layer where weather

occurs. It is where air masses, weather fronts, and storms reside. Weather conditions are

governed by a number of factors, including solar radiation, atmospheric circulation, water vapor

and topography. However, the underlying driving force in all cases is the radiant energy from the

sun.

2.1 Solar Radiation and Differential Heating

The amount of incident sunlight influences the heating of the surface of the earth and the

overlying atmosphere. The radiation received directly from the sun is called solar radiation. 

The amount of incoming solar radiation received at a particular time and location (insolation) on

the earth is governed by:
April 2004 Page G-2

Exhibit 1. Structure of the Atmosphere

• The transparency of the atmosphere (for example, clouds reflect solar radiation);

• Hours of daylight; and

• The angle at which the sun’s rays strike the earth.

The earth’s surface absorbs short-wave solar radiation and emits longer wavelength terrestrial

radiation. In the atmosphere, clouds, water vapor, and to a lesser extent carbon dioxide absorb

terrestrial radiation, which causes the atmosphere to warm. The atmosphere absorbs much more

terrestrial radiation than solar radiation. The atmosphere also radiates energy to outer space and

back to the earth’s surface. The earth-atmosphere system emits terrestrial radiation continuously. 

The atmospheric absorption of terrestrial radiation benefits the earth by retaining energy that

would otherwise be radiated to space. This phenomenon explains how air temperatures are

generally warmer on nights when cloud cover is present. The greenhouse effect is the

descriptive name given to the result of the energy exchange process that causes the earth’s

surface to be warmer than it would be if the atmosphere did not radiate energy back to earth. 

Gases such as carbon dioxide and methane (and other similarly behaving gases often called

greenhouse gases) also increase the ability of the atmosphere to absorb radiation (Exhibit 2).

The amount of solar radiation reaching the earth’s surface varies from place to place. In addition,

different types of earth surfaces (and man-made structures) vary in their ability to absorb and

store heat energy. For example, land masses absorb and store heat differently than water masses. 

The color, shape, surface texture, vegetation and presence of buildings can all influence the

heating and cooling of the ground. Generally, dry surfaces heat and cool faster than moist
April 2004 Page G-3

surfaces. Plowed fields, sandy beaches, and paved roads become hotter than surrounding

meadows and wooded areas. During the day, the air over a plowed field is warmer than over a

forest or swamp; during the night, the situation is reversed. The property of different surfaces

which causes them to heat and cool at different rates is referred to as differential heating. 

Exhibit 2. The Greenhouse Effect

Source: EPA’s “Global Warming Kids Site.”(1)

Heat is transferred within the atmosphere by conduction, convection, and advection. These

processes affect the temperature of the atmosphere near the surface of the earth. Conduction is

the process by which heat is transferred through matter without movement of the matter itself. 

For example, the handle of an iron skillet becomes hot due to the conduction of heat from the

stove burner. Conduction occurs from a warmer to a cooler object. Heat transfer also occurs due

to the movement of atmospheric gases. Meteorologists use the term convection to denote the

transfer of heat that occurs mainly by vertical motion. Air that is warmed by a heated land

surface will rise because it is lighter than the surrounding air. Likewise, cooler air aloft will sink

because it is heavier than the surrounding air. Meteorologists use the term advection to denote

heat transfer that occurs mainly by horizontal motion. All of these energy exchange processes,

particularly between the earth surface and the atmosphere, produce the complex atmospheric

motions of weather. As a result of these process air toxics maybe widely distributed far from

their location of origin.

2.2 Effects of Topography

The physical characteristics of the earth’s surface are referred to as terrain features or

topography. Topography can be grouped into four general categories: flat, mountain/valley,
April 2004 Page G-4

land/water, and urban. Topography also causes two types of turbulence in the atmosphere. As

noted above, topography causes thermal turbulence through differential heating. Topography

causes mechanical turbulence as the result of the wind flowing over different sizes and shapes

of objects. Physical features induce a frictional effect on wind speed and direction. For example,

urban settings with dense construction and tall buildings exert a strong frictional force on the

wind causing it to slow down, change direction, and become more turbulent.

Urban areas have a special effect on the atmosphere due to the high density of man-made

features. Building materials such as brick and concrete absorb and store heat more efficiently

than soil and vegetation found in rural areas. After sunset, the urban areas continue to radiate the

stored heat from buildings and paved surfaces. Air is warmed by this urban complex and rises to

create a dome (heat island) over an urban area. Large cities continue to emit heat throughout the

night and generally never completely cool down to the more stable surrounding conditions before

the sun rises and begins to heat the urban complex again. The overall effect of the urban

landscape is to increase the dispersion of air toxics through increased mixing. 

3.0 Atmospheric Motions

The differential heating of the earth’s surface causes imbalances in air pressure. The

atmospheric pressure at any point is due to the weight of the air pressing down from above due to

gravity. In any gas such as air, molecules are moving around in all directions at very high speeds. 

The speed actually depends on the temperature of the gas. Air pressure is caused by the

molecules of atmospheric gases bumping into each other and other surfaces and bouncing off. 

Air pressure is a function of the number of air molecules in a given volume and the speed at

which they are moving. When air is warmed, the molecules speed up, and air pressure increases. 

As air cools, the molecules slow down, and air pressure decreases.

3.1 Horizontal Air Motions 

Air moves in an attempt to equalize response to imbalances in pressure. The movement of air

(wind) tends to move from areas of high to low pressure. Wind is the basic element in the

general circulation of the atmosphere. Wind movements from small gusts to large air masses all

contribute to transport of heat, moisture and as well as air toxics around the earth. Winds are

always named by the direction from which they blow. Thus a “north wind” is a wind blowing

from the north to the south and a “westerly wind” blows from west to east. When wind blows

more frequently from one direction than from any other, the direction is termed the prevailing

wind. Section 4.1 provides further information on how meteorologists measure and describe

wind speed and direction.

Wind speed is heavily influenced by the presence or absence of friction (“drag”) and increases

rapidly with height about the ground level. Wind is commonly not a steady current but is made

up of a succession of gusts, slightly variable in direction, separated by lulls. Close to the earth,

wind gustiness is caused by irregularities of the surface, which create eddies, which are

variations from the main current of wind flow. Larger irregularities are caused by convection

(vertical transport of heat). These and other forms of turbulence contribute to the movement of

heat, moisture, dust, and pollutants into the air. See Section 2.2 for additional information on

how topography affects air motions.
April 2004 Page G-5

Air masses cover hundreds of thousands of square miles and extend upward for several miles. 

They are relatively homogeneous volumes of air with regard to temperature and moisture, and

they acquire the characteristics of the region over which they form and travel. Pollutants released

into an air mass tend to travel and disperse within the air mass. Air masses develop more

commonly in some regions than in others. Air masses are classified as maritime or continental

according to their origin over ocean or land, and as arctic, polar, or tropical depending principally

on the latitude of origin. Continental polar air masses are similar to arctic air masses, but not as

cold and dry as arctic air masses. The chief air masses that affect the weather of North America

are continental polar, maritime polar, and maritime tropical. 

Frontal patterns are formed by the interaction of adjacent air masses. A cold front is a transition

zone where a cold air mass is moving into the area previously occupied by a warm air mass. The

rise of warm air over an advancing cold front and the subsequent expansive cooling of this air

lead to cloud formation, and if sufficient moisture is available precipitation near the leading edge

of the front. A warm front is a transition zone where a warm air mass is moving into the area

previously occupied by a cold air mass. Precipitation commonly occurs in advance of a warm

front, as the warm air slowly rises above the cold air.

3.2 Vertical Air Motions

When air is displaced vertically, atmospheric behavior is a function of atmospheric stability. A

stable atmosphere resists vertical motion, and air that is displaced vertically in a stable

atmosphere tends to return to its original position. This atmospheric characteristic determines the

ability of the atmosphere to disperse pollutants. To understand atmospheric stability and the role

it plays in pollution dispersion, it is important to understand the mechanics of the atmosphere as

they relate to vertical atmospheric motion.

 The degree of stability of the atmosphere is determined by the temperature difference between

an air parcel and the surrounding air. This difference can cause the parcel to rise or fall. There

are three general categories of atmospheric stability.

• In stable conditions, vertical movement tends not to occur. Stable conditions occur at

night when there is little or no wind. Air that is lifted vertically will remain cooler, and

therefore denser than the surrounding air. Once the lifting force is removed, the air that

has been lifted will return to its original position.

• Neutral conditions (“well mixed”) neither encourage nor discourage air movement. 

Neutral stability occurs on windy days or when there is cloud cover such that there is

neither strong heating nor cooling of the earth’s surface. Air lifted vertically will

generally remain at the lifted height.

• In unstable conditions, the air parcel tends to move upward or downward and to continue

that movement. Unstable conditions most commonly develop on sunny days with low

wind speeds where strong solar radiation is present. The earth rapidly absorbs heat and

transfers some of it to the surface air layer. As warm air rises, cooler air moves

underneath. The cooler air, in turn, may be heated by the earth’s surface and begin to

rise. Under such conditions, vertical motion in both directions is enhanced, and

considerable vertical mixing occurs.
April 2004 Page G-6

Inversions occur whenever warm over-runs cold air and “traps” the cold air beneath. Within

these inversions there is little air motion, and the air becomes relatively stagnant. High air toxic

concentrations can occur within inversions due to the limited amount of mixing between the

“trapped” air and the surrounding atmosphere. Inversions can limit the volume of air into which

emissions are dispersed, even from tall stacks. Exhibit 3 illustrates the three major types of

inversions that are caused by different atmospheric interactions and can persist for different

amounts of time.

Most common is the radiation inversion, which occurs when the earth’s surface cools rapidly. 

As the earth cools, it also cools the layer of air close to the surface, which becomes trapped under

the layer of warmer air above. Radiation inversions usually occur in the late evening through the

early morning under clear skies with calm winds, when the cooling effect is greatest. In many

cases, solar radiation following sunrise results in vigorous vertical mixing, which breaks down

the inversion and disperses any trapped air pollutants. Under some conditions (e.g., thick fog),

the daily warming may not be strong enough to break down the inversion layer. Inversions

persisting for several days may lead to increased pollutant concentrations. This situation is most

likely to occur in an enclosed valley, where nocturnal, cool, downslope air movement can

reinforce a radiation inversion and encourage fog formation. 

The subsidence inversion is almost always associated with high pressure systems. Air in a high

pressure system descends and flows outward in a clockwise rotation in the Northern Hemisphere. 

As the air descends, the higher pressure present at lower altitudes enhances compression and

warming. The inversion layer thus formed is often elevated several hundred meters above the

ground surface during the day. At night, when the surface air cools, the base of the subsidence

inversion often descends, even to the ground. The clear, cloudless days characteristic of high

pressure systems encourage radiation inversions, so that there may be a surface inversion at night

and an elevated inversion during the day. Although the layer below the inversion may vary

diurnally, it will never become very deep. Subsidence inversions, unlike radiation inversions,

last a relatively long time. They are associated with both the semi permanent high pressure

systems centered on each ocean and the slow-moving high pressure systems that move generally

from west to east across the United States. When a high pressure system stagnates, pollutant

concentrations may become unusually high. The most severe air pollution episodes in the United

States have occurred either under a stagnant high pressure system (for example, New York in

November, 1966 and Pennsylvania in October, 1948) or under the eastern edge of the semi

permanent high pressure system associated with the Pacific Ocean (Los Angeles).

Advection inversions are associated with air masses moving across surfaces of different

temperatures than themselves. When warm air moves over a cold surface, the principles of

conduction and convection cool the air nearer to the surface, causing a surface-based inversion. 

This inversion is most likely to occur in winter when warm air passes over snow cover or

extremely cold land. The same type of inversion can occur when air cooled by a cold surface,

such as the ocean, flows towards a warmer air mass, such as inland air in the summer.
April 2004 Page G-7

Table 3. Types of Inversions
April 2004 Page G-8

4.0 Meteorological Data

Measuring and recording meteorological variables provides the necessary information to manage

the release of air contaminants into the atmosphere and to understand the transport and dispersion

of emitted air pollutants. The most useful data in air pollution studies are wind speed and

direction, ambient temperature and vertical temperature difference, solar radiation and mixing

height. For indirect exposure, precipitation data are needed as well. These same variables can be

used to make qualitative and quantitative predictions of ambient air toxic concentrations

resulting from the release of air toxics, and to conduct quantitative risk assessments.

4.1 Wind Speed and Direction

It is common to consider wind speed and wind direction as separate variables. Wind speed

determines the amount of initial dilution experienced by air toxics released into the atmosphere. 

Wind speed also influences the height to which the toxics will rise after being released from an

elevated source - as wind increases, the air toxics are kept lower to the ground, allowing them to

impact the ground at shorter distances downwind. 

Wind direction for meteorological purposes is defined as the direction from which the wind is

blowing. However, wind direction has both horizontal and vertical components. The horizontal

and vertical components of the wind direction can be measured with a bi-directional wind vane

or an anemometer. 

Wind roses are often used to graphically depict the prevailing wind direction of an area. The

wind rose depicts the relative frequency of wind direction, typically on a 16-point compass, with

north, east, south, and west directions going clockwise. Each ring on the wind rose represents a

frequency of the total. The WINDROSE program, which calculates and prints a frequency

distribution for wind speed and wind direction for 36 (10 degree) sectors, can be obtained from

EPA.(2)

Exhibit 4 presents an example wind rose for Brownsville, Texas. The right hand shows that the

winds are predominantly from the south-southeasterly direction. The left hand side shows that

the strongest winds occur between 14 and 21 UTC (8 A.M. to 3 P.M. CST). On average, 2 P.M.

is the windiest time of day, averaging just over 15 knots (18 UTC). The shaded portion of the

bar shows the frequency of winds over 20 knots. At noon CST, winds are over 20 knots

approximately 15 percent of the time.

The distribution of pollutants is determined by the wind directions. A wind rose can provide

information regarding the percentage of time that the direction(s) and speed(s) associated with a

certain air quality can be expected over a time period. However, due to the influences of local

terrain, possible coastal effects, exposure of the instruments, and temporal variability of the wind,

the wind rose statistics from a nearby weather station may not always be representative of true

wind speed and direction for the area of concern.
April 2004 Page G-9

Source: Brownsville CLIMATE page at:

 http://www.srh.noaa.gov/bro/roshelp.htm

Exhibit 4. Example of a Wind Rose

Another tool useful for understanding the distribution of pollutants is wind trajectories, which

are aerial maps showing the path taken by a parcel of air over a period of time. Trajectories are

important for understanding the transport of air toxics and/or the potential geographic regions

from which sources of air toxics may emanate. Trajectories illustrate estimates of the general

path that air has traveled over a recent time period in order to arrive at a particular location, and

where it is likely to be going immediately afterward. The meteorological dynamics that cause air

to rise or fall, and that determine its path, can affect air quality by carrying air toxics many miles

from their sources. Exhibit 5 presents an example of a trajectory map for the Northeastern

United States.

4.2 Other Important Meteorological Data

Both ambient air temperatures at a single level (typically 1.5 to 2 m) and temperature

differences between two levels (typically 2 m and 10 m) are useful in air pollution studies. 

These temperature measurements are used in calculations of plume rise and can be used in

determining atmospheric stability.

Solar radiation is related to the stability of the atmosphere. Cloud cover and ceiling height

(height of the base of the cloud deck that obscures at least half the sky) data, taken routinely at

National Weather Service (NWS) stations, provide an indirect estimation of radiation effects,

and are used in conjunction with wind speed to derive an atmospheric stability category. If

representative information is not available from routine NWS observations, it may be appropriate

to measure solar radiation for use in determining atmospheric stability. For information on the

use of cloud cover and ceiling height data in air toxics modeling, refer to EPA’s Guideline on

Air Quality Models.(3)
April 2004 Page G-10

Exhibit 5. Example of a Trajectory Map

Source: National Oceanic and Atmospheric Administration (NOAA) HYSPLIT Model. (4)

The vertical depth of the atmosphere through which vertical mixing takes place is called the

mixing layer. The top of the mixing layer is referred to as the mixing height. The mixing

height is an important variable in air toxic studies, as it limits the vertical mixing of air toxics.

Daytime mixing heights may reach as high as several kilometers during the day. Although

mixing heights are not typically measured directly, they can be approximated from routine

upper-air and surface meteorological measurements. In the daytime the mixing height is

determined by the depth of the layer thorough which the sun’s heating has established a well

mixed conditions. On clear nights, radiational cooling might be expected to establish an

inversions and reduce the mixing height to near zero. However, it has been found that in

metropolitan areas, the urban heat island effect keeps the mixing height between 100 and 200

meters. The mixing heights are used in air quality models as an upper boundary to which air
April 2004 Page G-11

toxics can be mixed. The level of the mixing height is most important for elevated stacks and

much less so for ground level sources. 

4.3 Sources of Meteorological Data

The principal federal sources for meteorological data include:

• The National Climatic Data Center (NCDC) located in Asheville, NC.

• The National Weather Service (NWS) Forecast Centers

• The EPA Support Center for Regulatory Models (SCRAM) at Research Triangle Park,

NC.

State climatological offices are excellent sources of meteorological data. Data can often be

obtained in a text format, and can be used in conjunction with applications that are available as

downloads from federal and state data Internet sites. Commercial and university Internet sites are

also sources of current weather conditions. 

The NCDC is the most extensive source of historical meteorological and climatological data.

EPA’s SCRAM site has surface and mixing height data that can be used to create wind roses

and/or used in air dispersion models. These data are for the major NWS stations throughout the

United States. The data are mostly for the years 1984 through 1992 (for surface data) or 1991

(for upper air data used for mixing heights). Exhibit 6 presents a list of Internet sites where

meteorological data are available.

Exhibit 6. Internet Sites with Meteorological Data

National Climatic Data Center ( http:// www.ncdc.noaa.gov/oa/ncdc.html)

EPA SCRAM Site (http://www.epa.gov/scram001/)

Weather Underground (http://www.wunderground.com/)

UNSYSIS (http://weather.unisys.com/)

NWS Pleasant Hill, MO (http://www.crh.noaa.gov/eax/)

Western Regional Climate Center (http://www.wrcc.dri.edu/)

Northeast Regional Climate Center

(http://met-www.cit.cornell.edu/nrcc_home.html)

Midwest Regional Climate Center (http://mcc.sws.uiuc.edu/)

High Plains Regional Climate Center (http://www.hprcc.unl.edu/)

Southern Regional Climate Center (http://www.srcc.lsu.edu/)

Southeast Regional Climate Center (http://www.sercc.com/)

WebMET.com (http://www.webmet.com/)
April 2004 Page G-12

1. U.S. Environmental Protection Agency. 2004. Global Warming Kids Site. Greenhouse

Effect. Updated March 1, 2004. Available at:

http://www.epa.gov/globalwarming/kids/greenhouse.html. (Last accessed March 2004).

2. U.S. Environmental Protection Agency. 2004. Technology Transfer Network. Support Center

for Regulatory Air Models, Meteorological Data, Related Programs. Updated March 8, 2004. 

Available at: http://www.epa.gov/scram001/tt24.htm#relatedprograms (Last accessed March

2004). 

3. U.S. Environmental Protection Agency. 2004. Technology Transfer Network. Support

Center for Regulatory Air Models, Guidance/Support, Modeling Guidance. Updated March

22, 2004. Available at http://www.epa.gov/scram001/tt25.htm#guidance (Last accessed

March 2004). 

4. Rolph, G.D. 2003. Real-time Environmental Applications and Display sYstem (READY)

Website. Available at: http://www.arl.noaa.gov/ready/hysplit4.html. NOAA Air Resources

Laboratory, Silver Spring, MD. (Last accessed March 2004)

References
Appendix H Data Quality Evaluation

Table of Contents

1.0 Introduction .................................................................. 1

2.0 Step 1: Gather All Data Available from the Sampling Investigation and Sort by Medium . . . . . 2

3.0 Step 2: Evaluate the Analytical Methods Used ...................................... 4

4.0 Step 3: Evaluate the Quality of Data with Respect to Sample Quantitation Limits ........... 5

4.1 Sample Quantitation Limits (SQLs) That Are Greater Than Benchmark Concentrations

..................................................................... 5

4.2 Unusually High SQLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4.3 When Only Some Samples in a Medium Test Positive For a Chemical ............. 8

4.4 When SQLs Are Not Available . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

4.5 When Air Toxics Are Not Detected in Any Samples in a Medium . . . . . . . . . . . . . . . . . 8

5.0 Step 4: Evaluate the Quality of Data with Respect to Qualifiers and Codes ................ 8

5.1 Types of Qualifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

5.2 Using the Appropriate Qualifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

6.0 Step 5: Evaluate the Quality of Data with Respect to Blanks .......................... 13

7.0 Step 6: Evaluate Tentatively Identified Compounds ................................. 14

8.0 Step 7: Compare Potential Contamination with Background .......................... 15

9.0 Step 8: Develop a Set of Data for Use in the Risk Assessment ......................... 17

10.0 Step 9: Further Limit the Number of Chemicals to Be Carried Through the Risk Assessment, If

Appropriate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

10.1 Conduct Initial Activities ................................................ 18

10.2 Group Chemicals by Class ............................................... 18

10.3 Evaluate Frequency of Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

10.4 Use a Toxicity-Weighted or Risk-based Screening Analysis .................... 19

11.0 Summarize and Present Data ................................................... 19

11.1 Summarize Data Collection and Evaluation Results in Text . . . . . . . . . . . . . . . . . . . . . 19

11.2 Summarize Data Collection and Evaluation Results in Tables and Graphics . . . . . . . . 21

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

April 2004 Page H-1

Acronyms for Appendix H

CLP = Contract Laboratory Program

CRDL = Contract-Required Detection Limit

CRQL = Contract-Required Quantitation Limit

EQL = Estimated Quantitation Limits 

DL = Detection Limit

FIT = Field Investigation Team

IDL = Instrument Detection Limit

MDL = Method Detection Limit

ND = Non-detect

PE = Performance Evaluation

PQL = Practical Quantitation Limit

QA/QC = Quality Assurance/Quality Control

QL = Quantitation Limit

RfC = Inhalation Reference Concentration

RfD = Oral Reference Dose

SQL = Sample Quantitation Limit

SVOC = Semivolatile Organic Chemical

TCL = Target Compound List

TIC = Tentatively Identified Compound

TOC = Total Organic Carbon

TOX = Total Organic Halogens

VOC = Volatile Organic Chemical

1.0 Introduction

This appendix presents information for assembling the analytical data available after a

monitoring investigation has been completed and deciding which of the data are of sufficient

quality to be used in the risk assessment. Each sample may have been analyzed for the presence

of many different air toxics, and many of those substances may have been detected. The

following nine steps describe an approach to organize the data for use in a risk assessment. This

stepwise approach is modified from that described in Chapter 5 of EPA’s Risk Assessment

Guidance for Superfund.

(1) Note that the application of this stepwise approach requires

considerable knowledge related to sampling and analysis methods and risk assessment and

therefore should be done in consultation with appropriate experts.

1. Gather all data available from the

sampling investigation and sort by

medium (Section 2);

2. Evaluate the analytical methods used

(Section 3);

3. Evaluate the quality of data with

respect to sample quantitation limits

(Section 4);

4. Evaluate the quality of data with

respect to qualifiers and codes

(Section 5);

5. Evaluate the quality of data with

respect to blanks (Section 6);

6. Evaluate tentatively identified

compounds (Section 7);

7. Compare potential contamination with

background (Section 8);

8. Develop a set of data for use in the

risk assessment (Section 9); and

9. Further limit the number of chemicals

to be carried through the risk

assessment, if appropriate (Section

10).

10. Summarize and present data (Section

11).

The outcome of this evaluation is (1) the identification of contaminants of potential concern

(COPC) that will be carried through the risk assessment and (2) reported concentrations that are

of acceptable quality for use in a quantitative risk assessment. If the nine data evaluation steps

are followed, the number of air toxics to be considered in the remainder of the risk assessment

usually will be less than the number of substances initially identified. A suggested process for

averaging acceptable data to develop chemical specific exposure concentrations is provided in

Appendix I.
April 2004 Page H-2

Definitions for Appendix H

Chemicals of Potential Concern. Air toxics that are evaluated in the risk assessment because they

have the potential to affect the risk management decision. The corresponding term for ecological risk

assessment are chemicals of potential ecological concern (COPEC). The risk assessment often finds

that most of the risk is associated with a subset of the COPC. The subset, which drives the risk

management decisions, is referred to as chemicals of concern (COC).

Common Laboratory Contaminants. Certain organic chemicals (e.g., acetone, 2-butanone,

methylene chloride, toluene, and the phthalate esters) that are commonly used in the laboratory and

thus may be introduced into a sample from laboratory cross-contamination.

Contract-required Quantitation Limit (CRQL). Chemical-specific levels that the laboratory must

be able to routinely and reliably detect and quantitate in specified sample matrices to meet prespecified data quality objectives. May or may not be equal to the reported quantitation limit of a given

chemical in a given sample. (This term is also used in the Superfund Program under their Contract

Laboratory Program.)

Detection Limit (DL). The lowest amount that can be distinguished from the normal “noise” of an

analytical instrument or method.

Non-detects (NDs). Chemicals that are not detected in a particular sample above a certain limit,

usually the quantitation limit for the chemical in that sample. Non-detects are often indicated by a “U”

data qualifier.

Positive Data. Analytical results for which measurable concentrations (i.e., above a quantitation

limit) are reported. May have data qualifiers attached (except a U, which indicates a non-detect).

Quantitation Limit (QL). The lowest level at which a chemical can be accurately and reproducibly

quantitated. Usually equal to the instrument detection limit multiplied by a factor of three to five, but

varies for different chemicals and different samples.

2.0 Step 1: Gather All Data Available from the Sampling Investigation and Sort by

Medium

Gather data, which may be from several different sampling periods and based on several

different analytical methods, from all available sources. Sort data by medium (i.e., air, water,

sediment, soil, and biota, if appropriate). Exhibit 1 illustrates a useful table format for presenting

data.

The data should be given to the risk assessor in a data summary report (or reports) that provides

information on a number of critical elements that allow the assessor to judge the adequacy of the

data to perform the risk analysis. Some of the critical elements include:

• Description of the study area,

• Sampling design and sampling locations,

• Procedures followed to ensure quality data (e.g., SOPs, QAPPs),

• Analytical methods and quantitation limits,
April 2004 Page H-3

• Chemical-specific results on a per sample basis,

Exhibit 1. Example of Output Format for Validated Data

Hypothetical Soil Sampling Results from Area X

Sample medium Soil Soil Soil

Sample ID SRB-3-1 SRB-3-1DU SRB-3-2

Sample or

screen depth 0-1' 0-1' 2-4'

Date collected 12/14/99 12/14/99 12/14/99

Air Toxic SQL(a) Concentration

Qualifier(b) SQL(a) ConcentrationQualifier(b) SQL(a) ConcentrationQualifier(b)

toxaphene 80 80 U 80 80 U 80 40 J

2,4,7,8-TCDD 20 10 J 20 8 J 200 200 U/J

lead 160 120 J 160 110 J 400 360 J

mercury 60 30 J 60 44 J 300 300 U/J

Note: All values other than qualifiers must be entered as numbers, not labels.

(a) Sample quantitation limit. Values for illustration only.

(b) Refer to Section 5.1 (Exhibit 3) for an explanation of qualifiers.

• Field conditions, including meteorological conditions,

• Data validation reports (both by the laboratory and any secondary validation), and

• A description of any issues with field collection, transportation/storage, or analysis that

impact the veracity of the data.

The data reports provided to the risk assessor must be sufficient to allow the assessor to judge

the completeness, comparability, representativeness, precision, and accuracy of the data. 

[A more thorough overview of the process for assessing the usability of data for risk assessment

purposes, including minimum data and documentation needs, is provided in reference 2. While

this document was developed for the Superfund program, it provides relevant information for the

evaluation of environmental monitoring data in a risk assessment context and, as such, is

referenced here. Assessors are strongly encouraged to review this document prior to planning

and scoping a assessment. This will help to ensure that all the information necessary to assess

the useability of data for risk assessment purposes will be developed during the sampling and

analysis phase of the assessment. (For example, assessing precision of sampling results is

usually performed by establishing duplicate monitors at one or more sampling stations. The

requirements for duplicate sampling must be written into the analytical plan during the planning

and scoping phase of the assessment.) Reference 2 may also be consulted for information on

assessing the useability of historical data for risk assessment.](2)
April 2004 Page H-4

Evaluate data from different time periods to determine if concentrations of air toxics are similar

or if changes have occurred between sampling periods (e.g., during different seasons of the

year). If the methods used to analyze samples from different time periods are similar in terms of

the types of analyses conducted and the QA/QC procedures followed, then the data may be

combined for the purposes of quantitative risk assessment. Usually, this means averaging at

least one year’s worth of data to develop an estimate of long term average concentration (see

Appendix I for a suggested methodology for combining results from air monitoring to estimate

exposure concentration for the inhalation pathway). If concentrations of air toxics change

significantly between sampling periods, it may be useful to also note temporal variation in the

risk characterization. If data are available that spans long periods of time (e.g., multiple years)

one could use only the most recent data in the quantitative risk assessment and evaluate older

data in a qualitative analysis of changes in concentrations over time. When data are eliminated

from a data set, justification for such elimination should be fully described in the risk assessment

report. (A good understanding of the risk management goals will help in deciding what data to

keep and how to combine data.)

3.0 Step 2: Evaluate the Analytical Methods Used

Group data according to the types of analyses conducted (e.g., Toxic Organic method,

semivolatiles analyzed by EPA methods for air) to determine which analytical method results are

appropriate for use in quantitative risk assessment.

Some types of data usually are not appropriate for use in quantitative risk assessment, even

though they may be available. For example, analytical results that are not specific for a

particular compound (e.g., total organic carbon [TOC], total organic halogens [TOX]), or results

from insensitive analytical methods (e.g., analyses using portable field instruments such as

organic vapor analyzers and other field screening methods) may be useful for identifying

potential monitoring locations and/or examining the potential fate and transport of contaminants. 

These types of analytical results, however, generally are not appropriate for quantitative risk

assessment. In addition, the results of analytical methods associated with unknown, few, or no

QA/QC procedures are generally eliminated from further quantitative use. (Note that one of the

purposes of the data quality objectives (DQO) process described in Chapter 6 and elsewhere in

this manual is to avoid the use of sampling and analysis protocols that will not provide data that

are useable for the risk assessment). These types of results, however, may be useful for

qualitative discussions of risk.

The outcome of this step is a set of study-specific data that has been developed according to a

standard set of sensitive, chemical-specific methods (see Chapters 10 and 19 for links to

identified, standardized methods).

Note however that even when standardized, verified field and analytical procedures and

associated QA/QC have been used during sampling and analysis, there is no guarantee that all

analytical results are consistently of sufficient quality and reliability for use in quantitative risk

assessment. Instead, it is important to determine – according to the steps discussed below – the

limitations and uncertainties associated with the data, so that only data that are appropriate and

reliable for use in a quantitative risk assessment are carried through the process.
April 2004 Page H-5

4.0 Step 3: Evaluate the Quality of Data with Respect to Sample Quantitation Limits

This step involves evaluation of quantitation limits (QLs) and detection limits (DLs) for all of

the air toxics assessed. This evaluation may lead to the re-analysis of some samples, the use of

“proxy” (or estimated) concentrations, and/or the elimination of certain air toxics from further

consideration (because they are believed to be absent in all samples). Types and definitions of

QLs and DLs are presented in the box on the next page. Before eliminating an air toxic because

they are not detected (or conducting any other manipulation of the data), the following points

should be considered:

• The sample quantitation limit (SQL) for a specific air toxic may be greater than

corresponding standards, criteria, or concentrations against which the concentrations will be

compared (e.g., RfCs, RfDs, or ecological benchmark levels). In this situation, the

“undetected” air toxic may be present at levels greater than these benchmarks and their

exclusion from the risk assessment may result in an underestimate of risk.

• A particular SQL may be significantly higher than positively detected values in other

samples in a data set.

These two points are discussed in detail in the following two subsections. A third subsection

provides guidance for situations where only some of the samples for a given medium test

positive for a particular chemical. A fourth subsection addresses the special situation where

SQLs are not available. The final subsection addresses the specific steps involved with

elimination of air toxics from the quantitative risk assessment based on their QLs.

4.1 Sample Quantitation Limits (SQLs) That Are Greater Than Benchmark

Concentrations

QLs needed for the sampling and analysis investigation should be specified in the sampling plan. 

For some air toxics, however, SQLs obtained from available analytical methods may exceed

certain concentrations of potential concern (e.g., RfCs, tissue sample concentrations that might

result in a dietary intake level that exceeds an RfD). Exhibits 10-10 and 10-11 identify some

known deficiencies in available air monitoring methods and some air toxics for which improved

monitoring methods are needed. Two points should be noted when considering this situation:

• Review of available information on sources and emissions, a preliminary determination of

COPC, and/or the results of fate and transport modeling prior to sample collection may

allow the risk assessor to identify when more sensitive sampling and/or analytical methods

may be needed before an investigation begins. This is the most efficient way to minimize the

problem of QLs exceeding levels of potential concern.

• Analytical laboratories may not be able to attain QLs in particular samples that meet data

quality requirements using standardized, verified procedures.

If an air toxic is not detected in any sample from a particular medium at the QL and a more

sensitive method is not available, then modeling data, as well as professional judgment, may be

used to evaluate whether the chemical may be present above the concentrations of potential

concern. If the available information indicates the chemical is not present, see Section 3.5 of this 
April 2004 Page H-6

Detection Limits and Quantitation Limits

Strictly interpreted, the detection limit (DL) is the lowest amount of a chemical that can be “seen”

above the normal, random noise of an analytical instrument or method. A chemical present below that

level cannot reliably be distinguished from noise. DLs are chemical-specific and instrument-specific

and are determined by statistical treatment of multiple analyses in which the ratio of the lowest amount

observed to the electronic noise level (i.e., the signal-to-noise ratio) is determined. On any given day

in any given sample, the calculated limit may not be attainable; however, a properly calculated limit

can be used as an overall general measure of laboratory performance.

Two types of DLs may be described: instrument DLs (IDLs) and method DLs (MDLs). The IDL is

generally the lowest amount of a substance that can be detected by an instrument; it is a measure only

of the DL for the instrument, and does not consider any effects that sample matrix, handling, and

preparation may have. The MDL, on the other hand, takes into account the reagents, sample matrix,

and preparation steps applied to a sample in specific analytical methods.

Due to the irregular nature of instrument or method noise, reproducible quantitation of a chemical is

not possible at the DL. Generally, a factor of three to five is applied to the DL to obtain a quantitation

limit (QL), which is considered to be the lowest level at which a chemical may be accurately and

reproducibly quantitated. DLs indicate the level at which a small amount would be “seen,” whereas

QLs indicate the levels at which measurements of concentration can be “trusted.”

Two types of QLs may be described: estimated quantitation limits (EQL - also sometimes referred to

as a practical quantitation limit or PQL) and sample QLs (SQLs). EPA’s Superfund Program

maintains a Contract Laboratory Program (CLP) as a means to obtain reliable analytical results from

many different laboratories. To participate in the CLP, a laboratory must be able to meet EPA’s EQL. 

This EQL is established by contract and, thus, is called a contract required quantitation limit (CRQL). 

CRQLs are chemical-specific and vary depending on the medium analyzed and the amount of

chemical expected to be present in the sample. As the name implies, CRQLs are not necessarily the

lowest detectable levels achievable, but rather are levels that a CLP laboratory should routinely and

reliably detect and quantitate in a variety of sample matrices. For most air toxics risk assessments,

SQLs, not CRQLs, will be the QLs of interest for most samples. In fact, for the same chemical, a

specific SQL may be higher than, lower than, or equal to SQL values for other samples. In addition,

preparation or analytical adjustments such as dilution of a sample for quantitation of an extremely high

level of only one compound could result in non-detects for all other compounds included as analytes

for a particular method, even though these compounds may have been present at trace quantities in the

environmental sample. Because SQLs take into account sample characteristics, sample preparation,

and analytical adjustments, these values are the most relevant QLs for evaluating non-detected

chemicals. Also note that because of the inability to accurately measure concentration at the MDL, the

SQL is used as he starting point for developing exposure concentrations where some of the samples in

a data set have detections of an analyte and others do not (see Appendix I).
April 2004 Page H-7

appendix for guidance on eliminating chemicals. If there is some indication that the chemical is

present, the only choices are to:

• Use modeling results in the risk assessment;

• Re-analyze selected samples using a more sensitive analytical method (if feasible); or

• Address the chemical qualitatively in the risk assessment.

In determining which option is most appropriate for an analysis, it may be helpful to assume the

air toxic is present at the SQL for purposes of an initial (tier 1) screening risk assessment. In this

way, risks that would be posed if the chemical is present at the SQL can be compared with risks

posed by other air toxics in the analysis.

4.2 Unusually High SQLs

Due to one or more sample-specific problems (e.g., matrix interferences), SQLs for a particular

chemical in some samples may be unusually high, sometimes greatly exceeding the positive

results reported for the same chemical in other samples from the data set. Even if these SQLs do

not exceed health-based standards or criteria, they may still present problems. If the SQLs

cannot be reduced by re-analyzing the sample, consider excluding the samples from the

quantitative risk assessment if they cause the calculated exposure concentration to exceed the

maximum detected concentration for a particular sample set. Exhibit 2 presents an example of

how to address a situation with unusually high QLs.

Exhibit 2. Example of Unusually High Quantitation Limits

In this hypothetical example, ambient air concentrations of benzene in air have been determined

using the TO-1 method.

Concentration (ppb)

Chemical Sample 1 Sample 2 Sample 3 Sample 4

 benzene 50 U(a) 59 200 U 74

(a) U indicates that benzene was analyzed for, but not detected; the value presented (e.g., 50 U) is

the SQL.

The ambient air concentrations presented in this example (i.e., 50 to 200 ppb) vary widely from

sample to sample. Assume a more sensitive analytical method would not aid in reducing the

unusually high QL of 200 ppb noted in Sample 3. In this case, the result for benzene in Sample 3

would be eliminated from the quantitative risk assessment because it would cause the calculated

exposure concentrations to exceed the maximum detected concentration (in this case 74 ppb). 

Thus the data set would be reduced to three samples: the non-detect in Sample 1 and the two

detected values in Samples 2 and 4.
April 2004 Page H-8

4.3 When Only Some Samples in a Medium Test Positive For a Chemical

Most analytes are not positively detected in each sample collected and analyzed. Instead, for a

particular chemical the data set generally will contain some samples with positive results and

others with non-detected results. The non-detected results usually are reported as SQLs. These

limits indicate that the chemical was not measured above certain levels, which may vary from

sample to sample. The chemical may be present at a concentration just below the reported

quantitation limit, or it may not be present in the sample at all (i.e., the concentration in the

sample is zero). Appendix I provides a suggested methodology for combining the results of a

dataset where some of the samples test positive for an analyte and others do not.

4.4 When SQLs Are Not Available

In some cases, laboratory data summaries may not provide the SQLs. Instead, MDLs, CRQLs,

or even IDLs may have been substituted wherever a chemical was not detected. Sometimes, no

detection or quantitation limits may be provided with the data. As a first step in these situations,

always attempt to obtain the SQLs, because these are the most appropriate limits to consider

when evaluating non-detected air toxics (i.e., they account for sample characteristics, sample

preparation, or analytical adjustments that may differ from sample to sample). Good planning

and clearly articulated directions to the laboratory will help ensure that the appropriate

information is provided to the risk assessor. The problem associated with incorrectly reported

data should only be an issue when evaluating historical data for which there was no preconsultation with the laboratory about what is to be provided in the data package.

If SQLs cannot be obtained, the MDL may be used as the QL, with the understanding that in

most cases this will underestimate the SQL (because the MDL is a measure of detection limits

only and does not account for sample characteristics or matrix interferences). The IDL should

rarely be used for non-detected air toxics since it is a measure only of the detection limit for a

particular instrument and does not consider the effect of sample handling and preparation or

sample characteristics.

4.5 When Air Toxics Are Not Detected in Any Samples in a Medium

After considering the discussion provided in the above subsections, generally eliminate those air

toxics that have not been detected in any samples of a particular medium. If information exists

to indicate that the air toxics are present, they should not be eliminated from the analysis. The

outcome of this step is a data set that only contains air toxics for which positive data (i.e.,

analytical results for which measurable concentrations are reported) are available in at least one

sample from each medium. Unless otherwise indicated, assume at this point in the evaluation of

data that positive data to which no uncertainties are attached concerning either the assigned

identity of the chemical or the reported concentration (i.e., data that are not “tentative,”

“uncertain,” or “qualitative”) are appropriate for use in the quantitative risk assessment.

5.0 Step 4: Evaluate the Quality of Data with Respect to Qualifiers and Codes

Various qualifiers and codes (hereafter referred to as qualifiers) may be attached to certain data

by either the laboratories conducting the analyses or by persons performing data validation. 

These qualifiers often pertain to QA/QC problems and generally indicate questions concerning
April 2004 Page H-9

chemical identity, chemical concentration, or both. All qualifiers must be addressed before the

chemical can be used in quantitative risk assessment. Qualifiers used by the laboratory may

differ from those used by data validation personnel in either identity or meaning. 

5.1 Types of Qualifiers

Exhibit 3 provides a list of the qualifiers that laboratories are permitted to use under the

Superfund CLP, along with their potential use in risk assessment. Exhibit 4 provides a similar

list addressing data validation qualifiers. (Note that the data qualifiers and their meanings

provided here are not consistent across all laboratories. In all cases, it is critical to discuss with

the lab what they mean by the data qualifiers they report.) In general, because the data

validation process is intended to assess the effect of QC issues on data usability, validation data

qualifiers are attached to the data after the laboratory qualifiers and supersede the laboratory

qualifiers. If data have both laboratory and validation qualifiers and they appear contradictory,

ignore the laboratory qualifier and consider only the validation qualifier. If qualifiers have been

attached to certain data by the laboratory and have not been removed, revised, or superseded

during data validation, then evaluate the laboratory qualifier itself. If it is unclear whether the

data have been validated, contact the appropriate data validation and/or laboratory personnel.

The type of qualifier and other site-specific factors determine how qualified data are to be used

in a risk assessment. As seen in Exhibits 3 and 4, the type of qualifier attached to certain data

often indicates how that data should be used in a risk assessment. For example, most of the

laboratory qualifiers for both inorganic chemical data and organic chemical data (e.g., J, E, N)

indicate uncertainty in the reported concentration of the chemical, but not in its assigned identity. 

Therefore, these data can be used just as positive data with no qualifiers or codes. In general,

include data with qualifiers that indicate uncertainties in concentrations but not in identification.

Exhibit 3. Example of Data Qualifiers and Their Potential Use in

Quantitative Risk Assessment: Superfund Contract Laboratory Program (CLP)

Qualifier Definition

Indicates:

Uncertain

Identity?

Uncertain

Concentration?

Include Data in

Quantitative

Risk

Assessment?

Inorganic Chemical Data(a)

B Reported value is <CRDL, but

>IDL. No No Yes

U Compound was analyzed for, but

not detected. Yes Yes ?

E Value is estimated due to matrix

interferences. No Yes Yes

M Duplicate injection precision

criteria not met. No Yes Yes
Exhibit 3. Example of Data Qualifiers and Their Potential Use in

Quantitative Risk Assessment: Superfund Contract Laboratory Program (CLP)

Qualifier Definition

Indicates:

Uncertain

Identity?

Uncertain

Concentration?

Include Data in

Quantitative

Risk

Assessment?

April 2004 Page H-10

N Spiked sample recovery not within

control limits. No Yes Yes

S

Reported value was determined by

the Method of Standard Additions

(MSA).

No No Yes

W

Post-digestion spike for furnace

AA analysis is out of control

limits, while sample absorbance is

<50% of spike absorbance.

No Yes Yes

* Duplicate analysis was not within

control limits. No Yes Yes

+

Correlation coefficient for MSA

was <0.995. No Yes Yes

Organic Chemical Data(b)

U Compound was analyzed for, but

not detected. Yes Yes ?

J

Value is estimated, either for a

tentatively identified compound

(TIC) or when a compound is

present (spectral identification

criteria are met, but the 

value is <CRQL).

No for TCL

chemicals

Yes for TICs

Yes ?

C Pesticide results were confirmed

by GC/MS. No No Yes

B Analyte found in associated blank

as well as in sample.©) No Yes Yes

E Concentration exceeds calibration

range of GC/MS instrument. No Yes Yes

D

Compound identified in an

analysis at a secondary dilution

factor.

No No Yes

A The TIC is a suspected aldolcondensation product. Yes Yes No
Exhibit 3. Example of Data Qualifiers and Their Potential Use in

Quantitative Risk Assessment: Superfund Contract Laboratory Program (CLP)

Qualifier Definition

Indicates:

Uncertain

Identity?

Uncertain

Concentration?

Include Data in

Quantitative

Risk

Assessment?

April 2004 Page H-11

X Additional flags defined

separately. –(d) -- --

(a) Source: U.S. EPA, 1988. Contract Laboratory Program Statement of Work for Inorganics Analysis: Multimedia, Multi-concentration. Office of Emergency and Remedial Response. SOW No. 788.

(b) Source: U.S. EPA, 1988. Contract Laboratory Program Statement of Work for Organics Analysis: Multimedia, Multi-concentration. Office of Emergency and Remedial Response. SOW No. 288.

©) See Section 6 for a discussion of blank contamination.

(d) Data will vary with laboratory conducting analyses.

Exhibit 4. Validation Data Qualifiers and Their Potential Use in

Quantitative Risk Assessment

Qualifier Definition

Indicates:

Uncertain

Identity?

Uncertain

Concentration?

Include Data in

Quantitative

Risk

Assessment?

Inorganic and Organic Chemical Data(a)

U

The material was analyzed for, but

not detected. The associated

numerical value is the SQL.

Yes Yes ?

J The associated numerical value is

an estimated quantity. No Yes Yes

R

Quality control indicates that the

data are unusable (compound may

or may not be present). Resampling and/or re-analysis is

necessary for verification.

Yes Yes No

Z No analytical result (inorganic

data only). -- -- --

Q No analytical result (organic data

only). -- -- --

N

Presumptive evidence of 

presence of material (tentative

identification)(b)

Yes Yes ?
Exhibit 4. Validation Data Qualifiers and Their Potential Use in

Quantitative Risk Assessment

April 2004 Page H-12

(a) Source: U.S. EPA. 1988. Laboratory Data Validation Functional Guidelines for Evaluating Inorganics

Analysis. Office of Emergency and Remedial Response.

U.S. EPA. 1988. Laboratory Data Validation Functional Guidelines for Evaluating Organics Analysis

(Functional Guidelines for Organics). Office of Emergency and Remedial Response.

(b) Organic chemical data only

Exhibit 5 provides examples showing the use of two commonly encountered data qualifiers: the

J qualifier, and the R qualifier. Basically, the suggestion is to use J-qualified concentrations the

same way as positive data that do not have this qualifier. If possible, note potential uncertainties

associated with the qualifier, so that if data qualified with a J contribute significantly to the risk,

then appropriate caveats can be attached. The R data qualifier indicates that the sample result

was rejected by the data validation personnel, and therefore this result should be eliminated from

the risk assessment.

Exhibit 5. Example Use of “J” and “R” Data Qualifiers

In this example, concentrations of benzene in an air monitor have been determined using a hypothetical

analytical method. Benzene was detected in these four samples at concentrations of 3,200 μg/l, 40

μg/l, and 20 μg/l; therefore, these concentrations – as well as the non-detect – should be used in

determining representative concentrations.

Chemical Sample 1 Sample 2 Sample 3 Sample 4

Benzene 3,200 J(a) 40 30 U(b) 20 J

(a) J = The numerical value is an estimated quantity

(b) U = Compound was analyzed for, but not detected. Value presented (e.g., 30 U) is the SQL.

In this example, concentrations of lead in surface water have been determined using a hypothetical

analytical method. These data have been validated, and therefore the R qualifers indicate that the

person conducting the data validation rejected the data for lead in samples 2 and 3. The “UR” qualifier

means that lead was not detected in Sample 3; however, the data validator rejected the non-detected

result. Eliminate these two samples so that the data set now consists of only two samples (Samples 1

and 4).

 Chemical Sample 1 Sample 2 Sample 3 Sample 4

Lead 310 500 R(a) 30 UR(b) 500

(a) R = Quality control indicates that the data are unusable (compound may not be present)

(b) U = Compound was analyzed for, but not detected. Value presented (e.g., 30 UR) is the SQL.

5.2 Using the Appropriate Qualifiers

The information presented in Exhibits 3 and 4 is based on 1988 EPA guidance documents

concerning qualifiers. The types and definitions of qualifiers may be periodically updated within

any analytical program, and EPA regions, states, and local governments may have their own data
April 2004 Page H-13

qualifiers and associated definitions. In general, the risk assessor should clearly understand the

specific data qualifiers used by a particular analytical program and use the resulting data

appropriately in the risk assessment. Make sure that definitions of data qualifiers used in the

data set for the analysis have been reported with the data and are current. Never guess about the

definition of qualifiers.

6.0 Step 5: Evaluate the Quality of Data with Respect to Blanks

Blank samples provide a measure of contamination that has been introduced into a sample set

either (1) in the field while the samples were being collected or transported to the laboratory, or

(2) in the laboratory during sample preparation or analysis. To prevent the inclusion of

non-site-related contaminants in the risk assessment, the concentrations of air toxics detected in

blanks must be compared with concentrations of the same air toxics detected in site samples. 

Exhibit 6 provides detailed definitions of different types of blanks. Blank data should be

compared with results from samples with which the blanks are associated. It is often impossible,

however, to determine the association between certain blanks and data. In this case, compare the

blank data with results from the entire sample data set. EPA’s Superfund Program has

developed guidelines for comparing sample concentrations with blank concentrations; note that

the requirements or practices for a given air toxic program may differ.

• Blanks containing common laboratory contaminants. As discussed in the EPA

documents cited in Exhibits 3 and 4, acetone, 2- butanone (or methyl ethyl ketone),

methylene chloride, toluene, and the phthalate esters are considered by EPA to be common

laboratory contaminants. If the blank contains detectable levels of common laboratory

contaminants, EPA guidance indicates that the sample results should be considered as

positive results only if the concentrations in the sample exceed ten times the maximum

amount detected in any blank. If the concentration of a common laboratory contaminant is

less than ten times the blank concentration, then EPA guidance indicates to conclude that the

chemical was not detected in the particular sample and consider the blank-related

concentrations of the chemical to be the quantitation limit for the chemical in that sample. 

Note that if all samples contain levels of a common laboratory contaminant that are less than

ten times the level of contamination noted in the blank, then completely eliminate that

chemical from the set of sample results.

• Blanks containing chemicals that are not common laboratory contaminants. As

discussed in the previously referenced guidance, if the blank contains detectable levels of one

or more organic or inorganic chemicals that are not considered by EPA to be common

laboratory contaminants, then consider sample results as positive only if the concentration of

the chemical in the sample exceeds five times the maximum amount detected in any blank. 

Treat samples containing less than five times the amount in any blank as non-detects, and

consider the blank-related chemical concentration to be the quantitation limit for the

chemical in that sample. Again, note that if all samples contain levels of a chemical that are

less than five times the level of contamination noted in the blank, then completely eliminate

that chemical from the set of sample results.
April 2004 Page H-14

Exhibit 6. Types of Blanks

Blanks are analytical quality control samples analyzed in the same manner as site samples. They are

used in the measurement of contamination that has been introduced into a sample either (1) in the field

while the samples were being collected or transported to the laboratory or (2) in the laboratory during

sample preparation or analysis. Four types of blanks – trip, field, laboratory calibration, and laboratory

reagent (or method) – are described below. A discussion on the water used for the blank also is

provided.

Trip Blank. This type of blank is used to indicate potential contamination due to migration of volatile

organic chemicals (VOCs) from the air on the site or in sample shipping containers, through the septum

or around the lid of sampling vials, and into the sample. A trip blank consists of laboratory distilled,

deionized water in a 40-ml glass vial sealed with a teflon septum. The blank accompanies the empty

sample bottles to the field as well as the samples returning to the laboratory for analysis; it is not

opened until it is analyzed in the lab with the actual site samples. The containers and labels for trip

blanks should be the same as the containers and labels for actual samples, thus making the laboratory

“blind” to the identity of the blanks.

Field Blank. A field blank is used to determine if certain field sampling or cleaning procedures (e.g.,

insufficient cleaning of sampling equipment) result in cross-contamination of site samples. Like the

trip blank, the field blank is a sample of distilled, deionized water taken to the field with empty sample

bottles and is analyzed in the laboratory along with the actual samples. Unlike the trip blank, however,

the field blank sample is opened in the field and used as a sample would be (e.g., it is poured through

cleaned sampling equipment or it is poured from container to container in the vicinity of a gas-powered

pump). As with trip blanks, the field blanks' containers and labels should be the same as for actual

samples.

Laboratory Calibration Blank. This type of blank is distilled, deionized water injected directly into

an instrument without having been treated with reagents appropriate to the analytical method used to

analyze actual site samples. This type of blank is used to indicate contamination in the instrument

itself, or possibly in the distilled, deionized water.

Laboratory Reagent or Method Blank. This blank results from the treatment of distilled, deionized

water with all of the reagents and manipulations (e.g., digestions or extractions) to which site samples

will be subjected. Positive results in the reagent blank may indicate either contamination of the

chemical reagents or the glassware and implements used to store or prepare the sample and resulting

solutions. Although a laboratory following good laboratory practices will have its analytical processes

under control, in some instances method blank contamination cannot be entirely eliminated.

Water Used for Blanks. For all the blanks described above, results are reliable only if the water

comprising the blank was clean. For example, if the laboratory water comprising the trip blank was

contaminated with VOCs prior to being taken to the field, then the source of VOC contamination in the

trip blank cannot be isolated (see laboratory calibration blank).

7.0 Step 6: Evaluate Tentatively Identified Compounds

Both the identity and reported concentration of a tentatively identified compound (TIC) is

questionable (see Exhibit 7). Two options for addressing TICs exist, depending on the relative

number of TICs compared to non-TICs. If the risk assessment involves a regulatory decision,

the risk assessor is strongly encouraged to consult the appropriate regulatory authorities about

how to address TICs in the risk assessment.
April 2004 Page H-15

• When few TICs are present. When only a few TICs are present, and either (a) no

information indicates that either a particular TIC may indeed be present (e.g., it is not present

in emissions from the source(s) being evaluated or other nearby sources), or (b) the estimated

concentration is relatively low, and therefore, the risk estimate would likely not be

dominated by the TIC, then generally do not include the TICs in the risk assessment.

• When Many TICs are present. If many TICs are present, or if TIC concentrations appear

high or site information indicates that TICs are indeed present, then further evaluation of

TICs is necessary. If sufficient time is available, use more sensitive analytical methods to

confirm the identity and to positively and reliably measure the concentrations of TICs prior

to their use in the risk assessment. If such methods are unavailable or impractical, then the

TICs should be included as COPC in the risk assessment and (usually) discussed

qualitatively in the risk characterization along with a discussion of the uncertainty in both

identity and concentration.

Exhibit 7. Tentatively Identified Compounds (TICs)

The set of compounds analyzed in a particular laboratory protocol may be a limited subset of the

organic air toxics that could actually be present in specific emissions being evaluated. Thus, a

laboratory analysis may indicate the presence of additional organic compounds not being specifically

evaluated. The presence of additional compounds may be indicated, for example, by“peaks” on a

chromatogram (a chromatogram is a paper representation of the response of the instrument to the

presence of a compound). The laboratory may be required to attempt to identify some of these

compounds (e.g., the highest peaks) using computerized searches of a library containing mass spectra

(essentially “fingerprints” for particular compounds). When the mass spectra match to a certain

degree, the compound (or general class of compound) is named; however, the assigned identity is in

most cases highly uncertain. These compounds are called tentatively identified compounds (TICs).

The analytical protocols being used by the laboratory may include procedures to obtain a rough

estimate of the concentrations of TICs. These estimates, however, generally are highly uncertain and

could be orders of magnitude higher or lower than the actual concentration. For TICs, therefore,

assigned identities may be inaccurate, and quantitation is certainly inaccurate. Due to these

uncertainties, TIC information often is not provided with data summaries. Additional sampling and

analysis using different or more sensitive methods may reduce the uncertainty associated with TICs

and, therefore, TIC information should be sought even if it is absent from data summaries.

8.0 Step 7: Compare Potential Contamination with Background

In some cases, a comparison of sample concentrations with background concentrations is useful

for identifying the relative contribution of the source(s) being evaluated and other potential

sources to the total concentrations to which a population may be exposed. Often, however, the

comparison of samples with background is unnecessary because the risk estimates resulting from

other sources are very low compared to those resulting from the source(s) being evaluated.

Information collected during the risk assessment can provide information on two types of

background chemicals: (1) naturally occurring chemicals that have not been influenced by

humans and (2) chemicals that are present due to anthropogenic sources. Either type of

background chemical can be either localized or widespread. Information on background

chemicals may have been obtained by the collection of background samples and/or from other
April 2004 Page H-16

sources (e.g., County Soil Conservation Service surveys, United States Geological Survey

reports). Background concentrations should be from the vicinity of the location sampled. For

example, background air samples are generally collected upwind from the study area to estimate

concentrations of chemicals in the air mass that is moving into the study area. For water,

samples are taken upstream of the area where deposition (or erosion of contaminated soils) is

occurring.

Background samples collected during the monitoring effort should not be used if they were

obtained from areas influenced or potentially influenced by the source(s) being evaluated. 

Instead, the literature sources mentioned in the previous paragraph may be consulted to

determine expected background levels of air toxics in the study area. Care must be taken in

using literature sources, because the data contained therein might represent nationwide variation

in a particular parameter rather than variation typical of the geographic region or geological

setting in which the site is located. For example, a literature source providing concentrations of

chemicals in soil on a national scale may show a wide range of concentrations that is not

representative of the variation in concentrations that would be expected within a particular study

area.

Both the concentration of the chemical in the study-area and the concentration in background

media should be clearly articulated in the risk assessment report. Background concentrations

should generally not be subtracted from study-area specific concentrations; rather, they should

be compared (e.g., as barcharts). Statistical analyses that indicate whether study-area and

background concentrations are different may also be presented. (In cases where background

comparisons will be made, the statistical methods that will be used to compare study-area

concentrations to background concentrations should be identified prior to the collection of

samples.)

As an example, chromium is present in air releases from a source in a study area and chromium

is also naturally occurring in study area soils. In this case, it may be necessary to include a

careful comparison of the relative magnitude of estimated exposure and risk due to background

vs. estimated exposure and risk from total (i.e., deposited chromium + background chromium) . 

This can be done by the bar chart method mentioned above and may be augmented by statistical

analyses that attempt to answer the question about whether study area soil concentrations of

chromium are statistically different from background soils. Again, consultation with the

appropriate decision making authorities is strongly encouraged to ensure that they get the type of

information that they will need to make their risk management decisions. (Note that, in general,

comparison with naturally occurring levels is commonly performed primarily for inorganic

chemicals such as metals, because the majority of organic air toxics released to the environment

are not naturally occurring (even though they may be ubiquitous). Similar to naturally occurring

background concentrations, anthropogenic levels resulting from human sources (other than those

being evaluated in the air toxics risk assessment) may also be present. For example, an

assessment that is evaluating exposures to dioxin from a specific source may also have to

contend with dioxin that is also present in the study area that has resulted from numerous other

small sources in the area (and possibly also from naturally occurring sources such as forest fires

and some amount of longer range transport). Similar to naturally occurring chemicals, some

combination of background sampling, literature values, modeling, and statistical analysis can be

performed to try and sort out how much of the concentrations and risk are due to the source(s) in

question and how much is present due to other human (and non-human) influences.
April 2004 Page H-17

9.0 Step 8: Develop a Set of Data for Use in the Risk Assessment

After the evaluation of data is complete as specified in previous sections, a list of the samples

(by medium) is made that will be used to estimate exposure concentrations. In addition, a list of

COPC (also by medium) will be needed for the quantitative risk assessment. This list should

include chemicals that were:

• Positively detected in at least one sample in a given medium, including (a) chemicals with no

qualifiers attached (excluding samples with unusually high detection limits), and (b)

chemicals with qualifiers attached that indicate known identities but unknown concentrations

(e.g., J-qualified data);

• Detected at levels significantly elevated above levels of the same chemicals detected in

associated blank samples;

• Only tentatively identified but either may be associated with emissions from the source(s)

being evaluated based on ancillary information or have been confirmed by additional

analysis; and/or

• Transformation products of air toxics demonstrated to be present.

Air toxics that were not detected in samples from a given medium (i.e., non-detects) but that may

be present at the site also may be included in the risk assessment if an evaluation of the risks

potentially present at the detection limit is desired.

10.0 Step 9: Further Limit the Number of Chemicals to Be Carried Through the Risk

Assessment, If Appropriate

For certain assessments, the list of air toxics potentially related to emissions from the source(s)

being evaluated and remaining after quantitation limits, qualifiers, blank contamination, and

background have been evaluated may be lengthy. Note, however, that often a modeling

analysis can identify the subset of air toxics in the emissions being evaluated that are most

likely to contribute significantly to risk, and therefore limit the scope of any subsequent

sampling and analysis effort. Carrying a large number of chemicals through a quantitative risk

assessment may be complex, and it may consume significant amounts of time and resources. 

The resulting risk assessment report may be difficult to read and understand, and it may distract

from the dominant risks. In these cases, the procedures discussed in this section – using

chemical classes, frequency of detection, essential nutrient information, and a concentration

toxicity screen – may be used to further reduce the number of COPC in each medium.

If conducting a risk assessment on a large number of chemicals is feasible (e.g., because of

adequate computer capability), then the procedures presented in this section may be omitted. 

However, the most important chemicals (e.g., those presenting 99 percent of the risk) – identified

after the risk assessment – may be the focus of the main text of the report, and the remaining

chemicals could be presented in the appendices.

10.1 Conduct Initial Activities
April 2004 Page H-18

There are several activities that are useful to conduct before implementing any of the procedures

described in this section. The risk assessor is strongly encouraged to consult with appropriate

decision making authorities prior to implementing these procedures to ensure that the resulting

processed data will meet the decision makers’ needs. These remaining initial activities include:

• Considering how the rationale for the procedure should be documented. The rationale

for eliminating chemicals from the quantitative risk assessment based on the procedures

discussed below should be clearly stated in the risk assessment report. This documentation,

and its possible defense at a later date, could be fairly resource- intensive. If a continuing

need to justify this step is expected, then any plans to eliminate chemicals should be

reconsidered.

• Examining historical information about the source(s) being evaluated. Chemicals

reliably associated with emissions from the source(s) being evaluated based on historical

information generally should not be eliminated from the quantitative risk assessment (at least

during the initial tiers of analysis), even if the results of the procedures given in this section

indicate that such an elimination is possible.

• Considering mobility, persistence, and bioaccumulation. Three factors that should be

considered are the mobility, persistence, and bioaccumulation of the chemicals. For

example, a highly volatile (i.e., mobile) chemical such as benzene, a long-lived (i.e.,

persistent) chemical such as dioxin, or a readily bioaccumulated chemical such as the PBHAPs, probably should remain in the risk assessment. These procedures do not explicitly

include a mobility, persistence, or bioaccumulation component, and therefore the risk

assessor must pay special attention to these factors.

• Considering special exposure routes. For some chemicals, certain exposure routes need to

be considered carefully before using these procedures. For example, some air toxics may

pose a significant risk in certain circumstances due to dermal contact. The procedures

described in this section may not account for exposure routes such as this.

10.2 Group Chemicals by Class

Some dose-response values used in characterizing risks are available only for certain chemicals

within a chemical class. For example, slope factors are available only for some of the polycyclic

aromatic hydrocarbons (PAHs). In such cases, the information provided in Chapter 12 (toxicity

evaluation) and information provided on EPA’s FERA website (http://www.epa.gov/ttn/fera/).

10.3 Evaluate Frequency of Detection

Chemicals that are infrequently detected may be artifacts in the data due to sampling, analytical,

or other problems, and therefore may not be related to the sources being evaluated. Consider the

chemical as a candidate for elimination from the quantitative risk assessment if: (1) it is detected

infrequently in one or perhaps two environmental media, (2) it is not detected in any other

sampled media or at high concentrations, and (3) there is no reason to believe that the chemical

may be present in emissions from the source(s) being evaluated. In particular, modeling results

may indicate whether monitoring data that show infrequently detected chemicals are

representative of only their sampling locations or of broader areas. Because chemical
April 2004 Page H-19

concentrations within a broad assessment area are spatially variable, the risk assessor can use

modeling results to compare infrequently detected chemical concentrations to those estimated

over broader areas when determining whether the subject chemicals are relevant to the overall

risk assessment. Judicious use of modeling to supplement available monitoring data often can

minimize the need to resort to arbitrarily setting limits on inclusion of infrequently detected

chemicals in the risk assessment.

In addition to available monitoring data and modeling results, the risk assessor should consider

other relevant factors (e.g., presence of sensitive subpopulations) in recommending appropriate

site-specific limits on inclusion of risk assessment.

The reported or modeled concentrations and locations of chemicals should be examined to check

for “hotspots” (localized areas of particularly high concentrations), which may be especially

important for short-term exposures and which therefore should not be eliminated from the risk

assessment. For PB-HAPs, always consider detection of particular chemicals in all sampled

media because some media may be sources of contamination for other media. In addition,

infrequently detected chemicals with concentrations that greatly exceed reference concentrations

should not be eliminated.

10.4 Use a Toxicity-Weighted or Risk-based Screening Analysis

The objective of this screening procedure is to identify the chemicals in a particular analysis that,

based on concentration and toxicity, are most likely to contribute significantly to the resulting

risk estimates. These procedures are described, along, with examples, in Chapter 6.

11.0 Summarize and Present Data

The section of the risk assessment report summarizing the results of the data collection and

evaluation should be titled “Identification of COPC.” Information in this section should be

presented in ways that readily support the calculation of exposure concentrations in the exposure

assessment portion of the risk assessment. Exhibits 8 and 9 present examples of tables to be

included in this section of the risk assessment report.

11.1 Summarize Data Collection and Evaluation Results in Text

In the introduction for this section of the risk assessment report, clearly discuss in bullet form the

steps involved in data evaluation. If the optional screening procedure described in Section 9 was

used in determining COPC, these steps should be included in the introduction. If both historical

data and current data were used in the data evaluation, state this in the introduction. Any special

site-specific considerations in collecting and evaluating the data should be mentioned. General

uncertainties concerning the quality associated with either the collection or the analysis of

samples should be discussed so that the potential effects of these uncertainties on later sections

of the risk assessment can be determined.

In the next part of the report, discuss the samples from each medium selected for use in

quantitative risk assessment. Provide information concerning the sample collection methods

used (e.g., grab, composite) as well as the number and location of samples. If any samples (e.g.,

field screening/analytical samples) were excluded specifically from the quantitative risk
April 2004 Page H-20

assessment prior to evaluating the data, document this along with reasons for the exclusion. 

Again, remember that such samples, while not used in the quantitative risk assessment, may be

useful for qualitative discussions and therefore should not be entirely excluded from the risk

assessment.

Discuss the data evaluation within the appropriate context for the risk assessment. For example,

the focus may be on a particular neighborhood within the assessment area; specific types of

modeled receptors; or specific geographic features such as a water body. For PB-HAPs, the

discussion should include those media (e.g., wastes, soils) that are potential sources of

contamination for other media (e.g., surface water/sediments). If no samples or data were

available for a particular medium, discuss this in the text. For soils data, discuss surface soil

results separately from those of subsurface soils. Discuss surface water/sediment results by the

specific surface water body sampled.

Exhibit 8. Example of Table Format for Presenting Air Toxics Sampled in Specific Media

Air Toxic

Concentration in Medium X

Frequency of

Detection(a)

Range of Sample

Quantitation Limits (SQLs)

(units)

Range of Detected

Concentrations

(units)

Background

Levels

Chemical A 3/25 2 - 30 320 - 4600 100 - 140

Chemical B(b) 25/25 1 - 32 17 - 72 --

-- Not sampled

(a) Number of samples in which the chemical was positively detected over the number of samples available

(b) Identified as a COPC based upon evaluation of data according to procedures described in text of report

For each medium, identify in the report the chemicals for which samples were analyzed, and list

the analytes that were detected in at least one sample. If any detected chemicals were eliminated

from the quantitative risk assessment based on evaluation of data (i.e., based on evaluation of

data quality, background comparisons, and the optional screening procedures, if used), provide

reasons for the elimination in the text (e.g., chemical was detected in blanks at similar

concentrations to those detected in samples or chemical was infrequently detected).
April 2004 Page H-21

Exhibit 9. Example of Table Format for Summarizing COPC in All Media Sampled

Air Toxic

Concentration

Air

(μg/m3

)

Soils

(mg/kg)

Surface Water

(μg/l)

Sediments

(μg/l)

Chemical A 0.5 - 225 5 - 1,100 2 - 30 --

Chemical B 0.1 - 22 0.5 - 6.4 -- 12 - 3650

Chemical C 0.01 - 2.2 -- 50 - 440 100 - 11,000

Chemical D 3 - 854 2 - 12 --

-- Not sampled

The final subsection of the text is a discussion of general trends in the data results. For example,

the text may mention (1) whether concentrations of COPC in most media were close to the

detection limits or (2) trends concerning chemicals detected in more than one medium or in more

than one operable unit at the site. In addition, the location of hot spots should be discussed, as

well as any noticeable trends apparent from sampling results at different times.

11.2 Summarize Data Collection and Evaluation Results in Tables and Graphics

As shown in Exhibit 8, a separate table that includes all chemicals detected in a medium can be

provided if appropriate. Chemicals that have been determined to be of potential concern based

on the data evaluation should be designated in the table with an asterisk to the left of the

chemical name.

For each chemical, present the frequency of detection in a certain medium (i.e., the number of

times a chemical was detected over the total number of samples considered) and the range of

detected or quantified values in the samples. Do not present the QL or similar indicator of a

minimum level (e.g., <10 mg/L, ND) as the lower end of the range; instead, the lower and upper

bound of the range should be the minimum and maximum detected values, respectively. The

range of reported QLs obtained for each chemical in various samples should be provided in a

separate column. Note that these QLs should be sample-specific; other types of

non-sample-specific values (e.g., MDLs or CRQLs) should be provided only when SQLs are not

available. Note that the range of QLs would not include any limit values (e.g., unusually high

QLs) eliminated based on the guidance in Section 3. Finally, naturally occurring concentrations

of chemicals used in comparing sample concentrations may be provided in a separate column. 

The source of these naturally occurring levels should be provided in a footnote. List the identity

of the samples used in determining concentrations presented in the table in an appropriate

footnote.

The final table in this section is a list of the COPC presented by medium at the site or by medium

within each operable unit at the site. A sample table format is presented in Exhibit 9. Ths

isopleth is another useful type of presentation of chemical concentration data (not shown). This
April 2004 Page H-22

1. U.S. Environmental Protection Agency. 1989. Risk Assessment Guidance for Superfund: 

Volume I. Human Health Evaluation Manual (Part A). Office of Emergency and Remedial

Response. Washington, DC, EPA/541/1-89/002, available at:

http://www.epa.gov/superfund/programs/risk/ragsa/index.htm

2. U.S. Environmental Protection Agency. 1992. Guidance for Data Useability in Risk

Assessment (Part A). Office of Emergency and Remedial Response, Washington, DC. 

Publication 92857-09A, PB92-93356, available at:

http://www.epa.gov/oerrpage/superfund/programs/risk/datause/parta.htm.

graphic characterizes the monitored or modeled concentrations of chemicals at a site and

illustrates the spatial pattern of contamination.

References
Appendix I Use of Air Monitoring Data to

Develop Estimates of Exposure

Concentration (Data Analysis and

Reduction)

Table of Contents

1.0 Introduction .................................................................. 1

2.0 Data Treatment and Handling of Non-Detects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

3.0 Statistical Methods: Characterization of Concentration Data ........................... 4

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

April 2004 Page I-1

Tentatively Identified Compounds (TICs)

As noted in Appendix H, TICs are chemicals

identified in the laboratory, but which cannot be

identified with complete accuracy. Given that there

is not certainty as to their identify (and because, there

often is no toxicity data for them), TICs are often

assess only qualitatively in the risk assessment. The

level of detail applied to TICs depends on their

tentative identification (are they known toxic

compounds), their concentration, known sources, and

frequency of detection. Depending on the answers to

these questions, the analyst may recommend that

re-sampling be performed to try to more accurately

determine the nature of the TICs.

1.0 Introduction

This appendix discusses the process of air monitoring data analysis and reduction, the goals of

which are to (1) extract and summarize air monitoring data needed for the risk assessment, (2)

use the data to develop estimates of exposure concentration (EC), and (3) present the results of

the air monitoring study in an informative and understandable format. In short, this Appendix

describes how to take the refined air monitoring data sets developed according to the processes

described in Appendix H and use them to develop estimates of exposure concentration. Standard

computer software packages, such as Microsoft Excel® or the Statistical Analysis System,® may

be used to generate summary statistics for each chemical and monitoring location. Summary

statistics should include:

• The frequency of detection, or the

proportion of total valid

measurements collected which were

present at or above the respective

sample quantitation limit (SQL) and

including detections marked with

certain data qualifier (e.g., “J” values -

see Appendix H);

• The range of concentrations detected

(highest and lowest concentrations

measured for each chemical at each

monitoring site – including J values);

• The statistical description of the data

(e.g., normally distributed,

log-normally distributed), based on standardized statistical tests;

• The range of sample quantitation limits (SQLs); and

• An arithmetic mean value, the standard deviation, the median value (i.e., 50th percentile),

and the 95th percentile upper confidence limit (95% UCL) of the arithmetic mean.

The mathematical formulas and procedures for calculating these summary statistics are provided

in Section 3 below.

Statistical analysis of air monitoring data may be conducted using standard methods such as

those outlined in EPA’s Guidance for Data Quality Assessment - Practical Methods for Data

Analysis.

(1) This manual provides a detailed description of the formulae that should be used in

estimating the parameters mentioned above, and reviews issues associated with data treatment

(e.g., treatment of non-detects, use of J-qualified data). EPA’s Calculating Upper Confidence

Limits for Exposure Point Concentrations at Hazardous Waste Sites (2) is also an important

reference to consider when evaluating air monitoring data for exposure assessments. Readers are

encouraged to review both of these document prior to using monitoring data to calculate

exposure concentrations.
April 2004 Page I-2

Data Qualifiers

Having obtained a monitoring result, it is necessary to assign a qualifier to it so decision-makers can

understand the quality of the result and, hence, the role the result might play in decisions (a more

complete discussion of data qualifiers is provided in Appendix H). 

• U Flag. If the value is below the MDL, the result should be flagged as <MDL or as U or

“undetected.” This indicates that it cannot be determined, within the limits described in the DQOs,

that the compound is present in the sample. (Note, however, that some labs flag data below the

SQL as U, even though they actually detect it. It is important to work through such details with a

laboratory prior to analysis of samples.)

• J Flag. If the result is above the MDL, but less than the SQL, the result should be flagged as J or

“estimated concentration.” This indicates that the compound was detected in the sample, and can

be quantified, but not within the limits on accuracy described in the DQOs. 

• R Flag. If there are significant problems with the sample (e.g. improper calibration, or extensive

holding time, or very low recovery efficiency), the result should be flagged as R or “unusable.” 

This might occur, for example, if calibration procedures are judged inadequate. If the compound is

of interest, and/or other results suggest the potential for significant concentration, then re-sampling

or re-analysis is usually necessary.

Interpretation of these flagged results in the context of a risk assessment is described in Chapters 5 and

6 of the EPA document Guidance for Data Usability in Risk Assessment, Part A (Publication 9285.7-

09A, Washington, DC, April 1992; available at

www.epa.gov/superfund/programs/risk/datause/parta.htm). Another excellent source is Exhibits 5-4

and 5-5 in EPA’s Risk Assessment Guidance for Superfund (RAGS) Part A, available at

www.epa.gov/oerrpage/superfund/programs/risk/ragsa/index.htm. Appendix H of this volume also

discusses this subject in some detail.

2.0 Data Treatment and Handling of Non-Detects

Calculation of summary descriptive statistics (arithmetic mean, standard deviation, median, 95%

upper confidence limit) requires resolution of certain issues regarding the treatment of sampling

data. Specifically, assumptions must be made regarding:

• Treatment of duplicate samples;

• Treatment of instances in which chemicals are not detected; and

• Use of measurements in which the identity of a chemical is certain but its concentration is

estimated with some uncertainty (often reported as “J-qualified” data).

Duplicate samples refer to the simultaneous collection or analysis of multiple (usually two)

samples under conditions that are kept as similar as possible. Field duplicates usually refer to

separate samples collected side-by-side in the field, while laboratory duplicates involve

separately analyzing portions of the contents of a single sample. Both types of duplicates serve

the similar purpose of providing a sense of the reliability, reproducibility, and precision of

measurements. Ideally, duplicate samples should yield the same results. Large differences in the

results of duplicate measurements potentially indicate uncertainty in data quality.
April 2004 Page I-3

The MDL or the SQL: Which One Should I Use

for Risk Assessment?

When including non-detected data in the averaging

processes described on this page, one may either

include the non-detected sample as 1⁄2 the MDL or 1⁄2

the SQL. The MDL is not appropriate for this task

because it is a statistical measure developed by each

lab for each analytical instrument and can fluctuate

from day to day. In other words, it is not a stable

measure of true detection “limit.” In addition, many

labs that actually do detect a chemical in a sample at

levels less than the quantitation limit do not routinely

report the detection because they cannot accurately

quantitate its concentration). It is for these two

reasons that 1⁄2 the SQL is used when including

nondetected samples in the averaging process. This

holds even when the lab in question routinely reports

J-valued data.

In general, once it is clear that there are no issues with field duplicate samples, they should be

treated as a single sample by simply averaging their results. In cases where a chemical is

detected in one but not both duplicates (or the data is J-qualified), the chemical should be

assumed to be present and the two values should be averaged using the procedure for handling

non-detects as described below.

When a chemical is not detected in any sample at a monitor, that chemical can usually be

removed from further consideration if there are no known problems with the method, the method

meets DQOs, and there is no reason to suspect that the chemical should have been detected (e.g.,

there are no known sources, and the chemical was also not found at other monitors). In some

instances, the monitoring methodology (or interferences by other substances) do not allow for

the detection of a substance, even when it is present. The assessors must weigh these types of

evidence when deciding to drop a chemical from further consideration.

Various procedures have been used in risk

assessments to treat non-detects (i.e.,

samples in which the chemical

concentration is not present at or higher

than the sample quantification limit

(SQL)), ranging from the assumption that

the chemical is absent (i.e., the true

concentration is zero) to the assumption

that the chemical was present in a sample

at a level infinitesimally beneath the SQL

(i.e. very close to the SQL and so

essentially equal to the SQL). Some

algorithms differentiate assignment of

values to non-detects based upon the

frequency of a chemical’s detection. For

example, if a chemical is detected in

almost all samples, a concentration equal

to (or some fraction of) the analytical

SQL is assigned to non-detects, but if the

chemical is detected in few or no samples,

a concentration of zero is assumed for non-detects. In general, the strategy described below may

be used to address the issue of non-detects. References 1 and 2 provide more information on this

subject and analysts are encouraged to become familiar with both of these documents prior to

beginning data analysis. Also note that the generic upon which the procedure described below is

based assumes approximately 30 or more samples collected over the course of a year are being

averaged to develop an estimate of long term exposure concentration; however, air toxics

monitoring sampling schemes usually collect samples on at least a one-in-six day schedule,

giving the analyst approximately 60 or more samples to work with. Sampling frequencies are

sometimes even greater.

• If less than 15% of the monitored concentrations of a given chemical at a given location are

below the SQL, then a value equal to 1⁄2 of the respective SQL is assigned to these

concentrations and these values are used in the calculation of summary statistics as described

below.
April 2004 Page I-4

• If greater than 90% of the monitored concentrations of a given chemical at a given location

are less than the respective SQL, no estimation of the statistical descriptors is undertaken

initially. If concentrations were only detected on a limited number of days (i.e., 1 to 3 days)

then an investigation may be undertaken to assess the potential sources for these chemicals

and the validity of the measurements. A knowledgeable statistician can help determine an

appropriate method for developing summary statistics from such a data set, if appropriate.

• If between 15% and 90% of the monitored concentrations of a given chemical at a given

location are greater than the respective SQL, then a value equal to 1⁄2 of the respective SQL is

assigned to these concentrations and these values are used in the calculation of summary

statistics as described below. For chemicals in this group that end up contributing

significantly to risk, a knowledgeable statistician may reevaluate the data according to the

procedures in appropriate guidance (e.g., those provided in references 1 and 2).

3.0 Statistical Methods: Characterization of Concentration Data

One method to estimate the long-term annual average concentration would be to calculate a

simple arithmetic mean for each analyte/monitor combination. The arithmetic mean, or average

is constructed from discrete sample measurements taken at the monitor over time. As noted

previously, constraints on resources almost always place limits on the amount of sampling

possible (e.g., air toxics samples usually cannot be collected every day). Instead, samples are

usually collected roughly one out of every six days and in a manner to eliminate obvious sources

of bias (e.g., samples are not uniformly collected on the same day of the week, or only on

weekdays or only on weekends). In addition, collecting samples for a year allows for an

evaluation of seasonal variability.

All factors being equal, one would expect the sampling results from such a monitoring program

to contain equal probabilities of sampling on days when pollutant concentrations may have been

relatively high as on days when pollutant concentrations may have been relatively low (or on

days when meteorological conditions were conducive to high ground-level concentrations and

days when they were not). Since samples are usually not collected every single day, however,

one cannot be absolutely certain that all possible conditions were sampled equally. The

arithmetic mean concentration is thus subject to uncertainty due to a number of factors,

including:

• Daily variability in concentrations;

• The ability to measure only a finite number of instances from the distribution of

concentrations over time; and

• Potential inaccuracy in individual measurements of concentrations.

This uncertainty produces a result in which the simple arithmetic mean of sampling results may

underestimate, approach, or overestimate the true annual average. (The example below

illustrates how three different monitoring data sets taken at the same monitor may result in an

average concentration that underestimates, overestimates, or is close to the true long term

average concentration.) Given this uncertainty in the use of the arithmetic mean concentration to

describe “average” exposure concentration, the 95% Upper Confidence Limit of the mean (95%

UCL) is commonly used as a public health protective estimate of the true annual average. 

Proceeding in this manner is likely to overestimate the true long-term average exposure;
April 2004 Page I-5

True (but

Unknown)

Average

Air Concentration

95% UCL

Sample Set C

Average of 

Sample Set

Sample Set A Sample Set B

True (but

Unknown)

Average

Air Concentration

95% UCL

Sample Set C

Average of 

Sample Set

Sample Set A Sample Set B

however, this method virtually obviates the risk of underestimating the true exposure. EPA’s

Superfund program has routinely used this procedure to evaluate exposures at hazardous sites

and this process has garnered long term acceptance as a public health protective approach, in

light of the uncertainties.

Example Showing How Simple Arithmetic Mean

Does Not Always Represent the True Annual Average

Distributional Analysis

To calculate the 95% UCL for a chemical data set from a monitor, it is necessary to understand

its underlying statistical distribution, including whether the sampling results are normally or

lognormally distributed. Once the analysis goes beyond these commonly understood

distributional types, the level of statistical sophistication can increase substantially. EPA’s

Office of Air Quality Planning and Standards (OAQPS) has developed the following pragmatic

strategy to evaluate the distribution of monitoring data sets; however, other approaches are

available (see references 1 and 2). Specifically, EPA suggests the following procedure:

• Inspect each data set for normality using standard test procedures (e.g., Shapiro-Wilk Test,

Komolgorov-Smirnoff Test, or Filibens Test). If the assumption of normality holds, then the

summary descriptive statistics, including the 95% UCL, should be calculated as described

below with the equations based on the statistical assumption of a normal distribution.

• If the data are not normally distributed, then they are presumed to be lognormal and are

log-transformed by taking the natural logarithm of the measured concentrations. The

assumption of normality is then used to test the transformed data. If the assumption of

normality holds for the transformed data, the summary descriptive statistics, including he
April 2004 Page I-6

95% UCL, are developed with the transformed data using the equations based on the

statistical assumption of a lognormal distribution.

• If the transformed data are not lognormal, they may be treated initially as lognormal. For

chemicals in this group that significantly contribute to risk, a knowledgeable statistician may

reevaluate the data (e.g., according to the procedures suggested in References 1 and 2).

The use of this simple and pragmatic approach to data analysis allows most scientists and

engineers with a basic background in statistics to perform these analyses without access to

advanced statistical analysis resources. Presuming a data set is lognormally distributed generally

results in a 95% UCL that is conservative and, thus, public health protective. Only those

chemicals that the initial risk characterization identifies as being significant risk drivers would 

be reevaluated with more robust statistical procedures, depending on the needs of the risk

manager.

STATISTICAL FORMULAS

The following Exhibits provide the basic equations for developing the 95% UCL for chemical

data sets that are either normally distributed (Exhibits 1 and 2) or lognormally – or presumed to

be lognormally – distributed (Exhibits 3 and 4). The Students t and H statistics that are needed

to perform these calculations are available in Gilbert’s 1987 book Statistical Methods for

Environmental Pollution Monitoring.

(3)

Normally Distributed Data Sets

Exhibit 1. Directions for Computing UCL for the Mean of a Normal Distribution – Student’s t

Let represent the XX X n randomly sampled concentrations. 1 2 n , , ...,

STEP 1: Compute the sample mean X

n

Xi

i

n

= =

∑

1

1

STEP 2: Compute the sample standard deviation s

n

X X i

i

n

= − − =

∑ 1

1

2

1

( )

STEP 3: Use a table of quantiles of the Student’s t distribution to find the (1-")

th quantile of the

Student’s t distribution with n-1 degrees of freedom. For example, the value at the 0.05

level with 40 degrees of freedom is 1.684. A table of Student’s t values can be found in

Gilbert (1987, page 255, where the values are indexed by p = 1-", rather than " level). 

The t value appropriate for computing the 95% UCL can be obtained in Microsoft Excel®

with the formula TINV ((1-0.95)*2, n-1).

STEP 4: Compute the one-sided (1-") upper confidence limit on the mean

UCL X t s n 1 1 − −n = + α α, /
April 2004 Page I-7

Exhibit 2. An Example Computation of UCL for a Normal Distribution – Student’s t

25 VOC samples were collected from an air monitoring station and analyzed for a specific chemical. 

The values observed are 228, 552, 645, 208, 755, 553, 674, 151, 251, 315, 731, 466, 261, 240, 411,

368, 492, 302, 438, 751, 304, 368, 376, 634, and 810 μg/m3

. It seems reasonable that the data are

normally distributed, and the Shapiro-Wilk W test for normality fails to reject the hypothesis that they

are (W = 0.937). The UCL based on Student’s t is computed as follows:

STEP 1: The sample mean of the n = 25 values is x = 451

STEP 2: The sample standard deviation of the values is s = 198

STEP 3: The t-value at the 0.05 level for 25-1 degrees of freedom is t0 05 25 1 . , 1710 . − =

STEP 4: The one-sided 95% upper confidence limit on the mean is therefore:

95% 451 1710 198 25 519 UCL =+ × = (. / )

Lognormally Distributed Data

Exhibit 3. Directions for Computing UCL for the Mean of a Lognormal

Distribution – Land Method

Let represent the XX X n randomly sampled concentrations. 1 2 n , , ...,

STEP 1: Compute the arithmetic mean of the log-transformed data ln ln( ) X

n

Xi

i

n

= −

∑

1

1

STEP 2: Compute the associated standard deviation s

n X i X X

i

n

ln = (ln( ) ln ) − − =

∑ 1

1

2

1

STEP 3: Look up the H1-" statistic for sample size n and the observed standard deviation of the logtransformed data. Tables of these values are given by Gilbert (1987, Tables A-10 and A12) and Land (1975).

STEP4: Compute the one-sided (1-") upper confidence limit on the mean

UCL X s H s n 1 X X

2

− − 2 1 1 = ++ − α α exp(ln / / ln ln
April 2004 Page I-8

1. U.S. Environmental Protection Agency. 1998. Guidance for Data Quality Assessment –

Practical Methods for Data Analysis. EPA/QA-G9, QA97 Version, EPA 600/R96/O84,

Washington, DC, January 1998; available at www.epa.gov/swerust1/cat/epaqag9.pdf.

2. U.S. Environmental Protection Agency. 2002. Calculating Upper Confidence Limits for

Exposure Point Concentrations at Hazardous Waste Sites. Office of Emergency and

Remedial Response, Washington, DC, December 2002. OSWER 9285.6-10, available at

http://www.epa.gov/superfund/programs/risk/ragsa/ucl.pdf.

3. Gilbert, R.O. 1987. Statistical Methods for Environmental Pollution Monitoring. John Wiley

& Sons, New York, NY. 

Exhibit 4. An Example Computation of UCL for a lognormal Distribution – Land Method

31 VOC samples were collected from an air monitoring stations and analyzed for a specific chemical. 

The values observed are 2.8, 22.9, 3.3, 4.6, 8.7, 30.4, 12.2, 2.5, 5.7, 26.3, 5.4, 6.1, 5.2, 1.8, 7.2, 3.4,

12.4, 0.8, 10.3, 11.4, 38.2, 5.6, 14.1, 12.3, 6.8, 3.3, 5.2, 2.1, 19.7, 3.9, and 2.8 μg/m3

. Because of their

skewness, the data may be lognormally distributed. The Shapiro-Wilk W test for normality rejects the

hypothesis, at both the 0.05 and 0.01 levels, that the distribution is normal. The same test fails to reject

at either level the hypothesis that the distribution is lognormal. The UCL on the mean based on Land’s

H statistic is computed as follows:

STEP 1: Compute the arithmetic mean of the log-transformed data ln . X = 18797

STEP 2: Compute the associated standard deviation sln X = 08995 .

STEP 3: The H statistic for n = 31 and is 2.31 sln X = 0 90 .

STEP4: The one-sided 95% upper confidence limit on the mean is therefore:

95% 18797 08995 2 2 31 08995 31 1 14 4 2 UCL = + + × −= exp( . . / . . / ) .

It is statistically possible for the 95% UCL confidence limit of the mean to exceed the maximum

measured concentration for a chemical. If this exceeding occurs, the maximum concentration of

the chemical is commonly used in place of the 95th percentile upper confidence limit as the

exposure concentration, with certain caveats (see reference 2).

References
April 2004 Page J-1

Appendix J Air Monitoring and Sampling

Methods

This appendix contains a summary of monitoring and sampling methods for a variety of organic

and inorganic compounds in ambient air. Each approach is described briefly, with a listing of

compounds for which it is appropriate, the detection limit, and a summary of advantages and

disadvantages in using the approach. Descriptions of the methods can be downloaded from the

EPA’s Ambient Monitoring Technology Information Center (AMTIC) website

(www.epa.gov/ttn/amtic/airtox.html).

The measurement process generally relies on collecting a sample in the field, followed by a

return to the lab for analysis. A number of methods are used for initial collection of samples in

the field:

1. Sampling tubes, in which air is drawn through a tube containing a sorbent specific to the

compound being sampled, and the tube returned to the lab for analysis. Possible sorbents in

the tube are organic polymers; carbon (molecular, activated, etc); polyurethane foam; silica

gel; and dinitrophenylhydrazone (DNPH). Multi-sorbents also are available.

2. Filters, in which air is drawn through a fiber (often a glass fiber) filter, collecting the

sampled compound, and returned to the lab for analysis. In some methods, air is drawn over

an absorbent onto which the chemical sorbs. In some methods, a chemical reaction occurs

that converts the air toxics to another material that is then analyzed.

3. Cryogenic traps, in which air is drawn into a chamber at low temperature, condensing the

compound out of the air. The trap and condensate are returned to the lab for analysis.

4. Evacuated chambers, in which air is drawn into a chamber under vacuum. The chamber is

returned to the lab for analysis.

An important consideration in the use of such methods is the available time between collection

and analysis of samples. The compounds will degrade during the intervening holding period,

and so this holding period should not exceed maximum allowed times (holding times depend on

the method and compound (consult the AMTIC website for information on QA/QC for air

monitoring).
April 2004 Page J-2
April 2004 

Method

Designation

Applicable

Compounds

Approach Detection

Limit Advantages 

TO-1 VOCs (80o to

200o C); e.g.benzene,toluene, xylenes.

Ambient air is drawn through organicpolymer sorbent where certaincompounds are trapped. The cartridge istransferred to the lab, thermallydesorbed and analyzed using GC/MS orGC/FID.

0.01 to 100 ppbv Good data base; large sample

volume; water vapor not collected;wide variety of compoundscollected; low detection limits;standard procedures available;practical for field use.

Highly certain collecteabsorbemultiple volume desorptidifficulstructurcontamiartifact 

TO-2 Highly volatile

VOCs (-15o to 120o C);e.g. vinylchloride,chloroform,chlorobenzene.

Selected volatile organic compounds arecaptured on carbon molecular sieveabsorbents. Compounds are thermallydesorbed and analyzed by GC/MS orGC/FID techniques.

0.1 to 200 ppbv Trace levels of VOCs are collected

and concentrated; efficientcollection of polar compounds; widerange of application; highly volatilecompounds are absorbed; easy touse in field.

Some trare diffiinterferisomersde-activdesorptidifficul

TO-3 Nonpolar VOCs

(-10o to 200o C);e.g. vinylchloride,methylenechloride,acrylonitrile.

Vapor phase organics are condensed in acryogenic trap. Carrier gas transfers thecondensed sample to a GC column.Absorbed compounds are eluted fromthe GC column and measured by FID orECD.

0.1 to 200 ppbv Collects a wide variety of VOCs;

standard procedures are available;contaminants common to absorbentmaterials are avoided; low blanks;consistent recovery; large data base.

Moisturfreezing difficulintegratcompoutimes in

TO-4 Pesticides and

PCBs; e.g.PCBs, 4,4-DDE,DDT, DDD.

Pesticides/PCBs trap on filter and PUFabsorbent trap. Trap is returned to lab,solvent extracted and analyzed byGC/FID/ECD or GC/MS.

0.2 pg/m3 to 200

ng/m3

Low detection limits; effective forbroad range of pesticides and PCBs;PUF reusable; low blanks; excellentcollection and retention efficienciesfor common pesticides and PCBs.

Breakdooccur wcontamiincrease some sestorageorganicindividuECD us

TO-5 Aldehydes and

Ketones; e.g.formaldehyde,acetaldehyde,acrolein.

Air sample is drawn through DNPHimpinger solution using a low volumepump. The solution is analyzed usingHPLC with a UV detector.

1 to 50 ppbv Specific for aldehydes and ketones;

good stability for derivativecompounds formed in the impingers;low detection limits.

Sensitivpotentiaover lonaldehydunresolv
Method

Designation

Applicable

Compounds

Approach Detection

Limit Advantages 

April 2004 

TO-6 Phosgene Ambient air is drawn through a midget

impinger containing 10 ml of 2/98aniline/toluene (v/v). Phosgene reactswith aniline to form 1,3-diphenylureaand is analyzed using reverse-phaseHPLC with a UV absorbance detectoroperating at 254 nm.

1 to 50 ppbv Good specificity; good stability for

derivative compounds formed in theimpingers; low detection limits.

Chlorofmay intaniline of midgapplicat

TO-7 N-nitroso

dimethylamine

Ambient air is drawn through a cartridgecontaining Thermosorb/N absorbant totrap N-nitrosodimethyl amine. Thecartridge is returned to the lab andeluted with 5 ml of dichloromethane.The cartridge then is eluted in reversedirection with 2 ml of acetone. The Nnitrosodimethylamine is determined byGC/MS.

1 to 50 ppbv Good specificity; good stability for

derivative compounds formed on thecartridge; low detection limit for nnitrosodimethylamine; placement ofsorbent as first compound in sampletrain minimizes contamination;sampling system portable andlightweight.

Compouretentioions malimiting organic 

TO-8 Cresol and

phenol

Ambient air is drawn through twomidget impingers. Phenols are trappedas phenolates in NaOH solution, whichis returned to the lab and analyzed byHPLC.

1 to 250 ppbv 4,6-dinitro-2-methylphenol specific

to class of compounds; goodstability; detects non-volatile as wellas volatile phenol compounds.

Compouretentiophenolibe oxid

TO-9A* Dioxin, furan

and PCBs

Ambient air is drawn through a glassfiber filter and a polyurethane foam(PUF) absorbent cartridge with a highvolume sampler. The filter and PUFcartridge are returned to the lab andextracted using toluene. The extract isconcentrated using the Kudrena-Danishtechnique, diluted with hexane, andcleaned up using columnchromatography. The cleaned extractthen is analyzed by high resolutionGC/high resolution MS.

0.25 to 5000pg/m3

Cartridge is reusable; excellentdetection limits; easy to precleanand extract; excellent collection andretention efficiencies; brad database;proven methodology.

Analytifrom PCchlorinanapthalsimilar fractionDs/Fs amatter aduring sanalytic(HRGCreadily importaanalysis particle
Method

Designation

Applicable

Compounds

Approach Detection

Limit Advantages 

April 2004 

TO-10A Pesticides; e.g.

heptachlor,chlordane,dieldrin, aldrin

A low volume sample (1-5 L/min) ispulled through a PUF plug to traporganochlorine pesticides. Aftersampling, the plug is returned to the lab,extracted and analyzed by GC coupledto multi-detectors (ECID, PID, FID,etc).

1 to 100 ng/m3 Easy field use; proven methodology;

easy to clean; effective for broadrange of compounds; portable; goodretention of compounds.

ECD anMS) are variety target afurans morganocchlordaand can quantifisensitivanalytes

TO-11A Formaldehyde,

other aldehydesand ketones; e.g.formaldehyde,acetaldehyde,acrolein.

An ambient air sample is drawn througha DNPH cartridge at a rate of 500 to1200 ml/minute. The cartridge isreturned to the lab in screw-cap glassvials. The cartridge then is removedfrom the vial and washed withacetonitrile by gravity feed elution. Theeluate is diluted volumetrically and analiquot is removed for determination ofthe DNPH-formaldehyde derivative byisocratic reverse phase HPLC with UVdetection at 350 nm.

0.5 to 100 ppbv Placement of sorbent as first

element in the sampling trainminimizes contamination; largedatabase; proven technology;sampling system is portable andlightweight.

Isometrother coHPLC rformaldCarbonymay degnot usedthe DNPsamplinUV lighcarbony

TO-12 Non-methane

organiccompounds(NMOC)

Ambient air is drawn into a cryogenictrap, where the non-methane organiccompounds (NMOCs) are concentrated.The trap is heated to move the NMOCsto the FID. Concentration of NMOCs isdetermined by integrating under thebroad peak. Water correction isnecessary.

0.1 to 200ppmvC

Standard procedures are available;contaminants common to absorbentmaterials are avoided; low blanks;consistent recoveries; large database; good sensitivity; useful forscreening areas or samples; analysismuch faster than GC.

Moisturfreezing measure

TO-15 VOCs (polar and

non-polar);methanol,benzene, xylene,nitrobenzene

Whole air samples are collected in aspecifically-prepared canister. VOCsare concentrated on a solid sorbent trapor other arrangement, separated on a GCcolumn, and passed to an MS detectorfor identifaction and quantification.

0.2 to 25 ppbv Incorporates a multi-sorbent/dry

purge technique to manage water;has established methodsperformance criteria; providesenhanced provisions for QC; uniquewater management approach allowsanalysis of polar VOCs.

Expensidepends level.
Method

Designation

Applicable

Compounds

Approach Detection

Limit Advantages 

April 2004 

TO-16 Polar and nonpolar VOCs; e.g.

alcohols,ketones,benzene,toluene, oxylene,chlorobenzene.

VOCs are monitored using real-timelong-path open-path Fourier transforminfrared spectroscopy (FTIR).

25 to 500 ppbv Open path analysis maintains

integrity of samples; multi-gasanalysis saves money and time;path-integrated pollutantconcentration measurementminimizes possible samplecontamination and provides realtime pollutant concentration;applicable for special surveymonitoring; monitoring atinaccessible areas possible usingopen-path FTIR.

High lerequiredinterprelibrary limits thbe skillesubstanCO2 and 

with spe

TO-17 Polar and nonpolar VOCs; e.g.

alcohols,ketones,benzene,toluene, oxylene,chlorobenzene.

Ambient air is drawn through a multibed sorbent tube where VOCs aretrapped. The cartridge is returned to thelab, thermally desorbed and analyzed byGC/MS or other methods.

0.2 to 25 ppbv Placement of the sorbent as the first

element minimizes contaminationfrom other sample train components;large selection of sorbents to matchwith target analyte list; includespolar VOCs; better watermanagement using hydrophobicsorbents than Compendium MethodTO-14A; large database; proventechnology; size and cost advantagesin sampling equipment.

Distribufor qualclean-up possibilmust puunit for VOCs iabsorbe

IO-1 Suspended

particulatematter (SPM);continuousmeasurement.

Ambient air is drawn at a rate ofapproximately 16 to 17 L/minutethrough a virtual impact or cyclonicflow filter. Particle build-up on a filtertape is determined continuously eitherthrough measurement of attenuation ofbeta particles incident on the tape orthrough an oscillating pendulum. 

3micrograms/m3.

Less sensitive to temperature,pressure and humidity fluctuationsthan other continuous methods.

Results collectioscillatoexterna

IO-2 Suspended

particulatematter (SPM);integratedmeasurement.

Ambient air is drawn through a filterwith a high volume sampler, with large(> 10 micron) particles removed prior tothe filter. The filter is weighed beforeand after sampling, with dessication toremove water vapor. Mean particulateconcentration is determined from massgain and air flow rate.

1 microgram/m3 Well established methodology;

relatively simply technique toemploy

Balance be precicollecticompletobtaine
Method

Designation

Applicable

Compounds

Approach Detection

Limit Advantages 

April 2004 

IO-3 Chemical

species analysisof filtercollected SPM.

Ambient air is drawn through a filterwith a high volume sampler, with large(> 10 micron) particles removed prior tothe filter. The filter is weighed beforeand after sampling, with dessication toremove water vapor. The filter then issubsampled and strips digested using amicrowave or hot acid extractiontechnique. Specific extracts areanalyzed by the appropriate method.

Depends oncompoundconsidered.

Advantages depend on chemicalspecies analyzed, but particlecollection has the advantages notedin IO-2.

Disadvaspecies 

IO-4 Reactive acidic

and basic gases;strong acidity ofatmospheric fineparticles. HNO3, NH3,

HCL, SO2, NH4,SO4, NO3

Based on measurement of the fineparticle strong acidity component of theatmosphere. Air is drawn through anannular denuder followed by a 37 mmTeflon filter to trap the fine particle acidaerosol. The filter is returned to the labfor extraction and analysis using anaequeous solution of perchloric acidfollowed by titration or pHdetermination.

Simple method of analysis; wellestablished methodology.

Withouremove gases, i

IO-5 Atmospheric

mercury

Low flow (for vapor phase) or higherflow (for particulate phase) ambient airstream is flowed over gold coated beadtraps and glass fiber filters. Mercurycontent is determined by cold-vaporatomic fluorescence spectrometry afterthermal desorption. 

30 pg/m3

(particulatephase) or 45pg/m3 for vapor

phase.

No known positive interferencesusing the 253.7 nm wavelength toexcite the mercury atoms.

Possible and watquenchedegrade 
Appendix K Equations For Estimating

Concentrations of PB-HAP

Compounds in Food and Drinking

Water

Table of Contents

1.0 Introduction ............ ............ ............ ............ ............ ...... 1

2.0 Calculation of PB-HAP Compound Concentrations in Soil ............ ............ ..... 1

2.1 Calculating Cumulative Soil Concentration (Cs) ............ ............ ............ . 2

2.2 Calculating the PB-HAP compound Soil Loss Constant (ks) ............ ............ .... 3

2.2.1 PB-HAP compound Loss Constant Due to Biotic and Abiotic Degradation (ksg) ..... 4

2.2.2 PB-HAP compound Loss Constant Due to Soil Erosion (kse) ............ ........ 5

2.2.3 PB-HAP compound Loss Constant Due to Runoff (ksr) ............ ............ . 6

2.2.4 PB-HAP compound Loss Constant Due to Leaching (ksl) ............ ........... 6

2.2.5 PB-HAP compound Loss Constant Due to Volatilization (ksv) ............ ....... 7

2.3 Calculating the Deposition Term (Ds) ............ ............ ............ ......... 8

2.4 Universal Soil Loss Equation (USLE) ............ ............ ............ ......... 9

2.5 Site-Specific Parameters for Calculating Cumulative Soil Concentration ............ ...... 9

2.5.1 Soil Mixing Zone Depth (Zs) ............ ............ ............ .......... 9

2.5.2 Soil Dry Bulk Density (BD) ............ ............ ............ ........... 9

2.5.3 Available Water (P + I - RO - Ev) ............ ............ ............ ..... 10

2.5.4 Soil Volumetric Water Content (2sw) ............ ............ ............ ... 10

3.0 Calculation of PB-HAP Compound Concentrations in Produce ............ ............ 10

3.1 Aboveground Produce Concentration Due to Direct Deposition (Pd) ............ ........ 11

3.1.1 Interception Fraction of the Edible Portion of Plant (Rp) ............ ........... 12

3.1.2 Plant Surface Loss Coefficient (kp) ............ ............ ............ .... 12

3.1.3 Length of Plant Exposure to Deposition per Harvest of Edible Portion of Plant (Tp) . 12

3.1.4 Standing Crop Biomass (Productivity) (Yp) ............ ............ ......... 12

3.2 Aboveground Produce Concentration Due to Air-to-Plant Transfer (Pv) ............ ..... 12

3.3 Produce Concentration Due to Root Uptake (Pr) ............ ............ ............ 13

4.0 Calculation of PB-HAP Compound Concentrations in Beef and Dairy Products ........... 14
4.1 Forage and Silage Concentrations Due to Direct Deposition (Pd) ............ ........... 15

4.1.1 Interception Fraction of the Edible Portion of Plant (Rp) ............ ........... 15

4.1.2 Plant Surface Loss Coefficient (kp) ............ ............ ............ .... 15

4.1.3 Length of Plant Exposure to Deposition per Harvest of the Edible Portion of Plant (Tp)

............ ............ ............ ............ ............ ........ 16

4.1.4 Standing Crop Biomass (Productivity) (Yp) ............ ............ ......... 16

4.2 Forage and Silage Concentrations Due to Air-to-Plant Transfer (Pv) ............ ........ 16

4.3 Forage, Silage, and Grain Concentrations Due to Root Uptake (Pr) ............ ......... 16

4.4 Beef Concentration Resulting from Plant and Soil Ingestion (Abeef) ............ .......... 17

4.4.1 Fraction of Plant Type i Grown on Contaminated Soil and Eaten by the Animal

(Cattle)(Fi) ............ ............ ............ ............ ........... 17

4.4.2 Quantity of Plant Type i Eaten by the Animal (Cattle) Each Day (Qpi) ........... 17

4.4.3 Concentration of PB-HAP compound in Plant Type i Eaten by the Animal (Cattle) (Pi)

............ ............ ............ ............ ............ ........ 18

4.4.4 Quantity of Soil Eaten by the Animal (Cattle) Per Day (Qs) ............ ........ 18

4.4.5 Average Soil Concentration Over Exposure Duration (Cs) ............ ......... 18

4.4.6 Soil Bioavailability Factor (Bs) ............ ............ ............ ....... 18

4.4.7 Metabolism Factor (MF) ............ ............ ............ ............ 18

4.5 PB-HAP compound Concentration In Milk Due to Plant and Soil Ingestion (Amilk) ......... 19

4.5.1 Fraction of Plant Type i Grown on Contaminated Soil and Eaten by the Animal (Dairy

Cattle) (Fi) ............ ............ ............ ............ ........... 19

4.5.2 Quantity of Plant Type i Eaten by the Animal (Dairy Cattle) Per Day (Qpi) ........ 19

4.5.3 Concentration of PB-HAP compound in Plant Type i Eaten by the Animal (Dairy Cattle)

(Pi) ............ ............ ............ ............ ............ ..... 20

4.5.4 Quantity of Soil Eaten by the Animal (Dairy Cattle) Per Day (Qs) ............ ... 20

4.5.5 Average Soil Concentration Over Exposure Duration (Cs) ............ ......... 20

4.5.6 Soil Bioavailability Factor (Bs) ............ ............ ............ ....... 20

4.5.7 Metabolism Factor (MF) ............ ............ ............ ............ 20

5.0 Calculation of PB-HAP Compound Concentrations in Pork ............ ............ ... 20

5.1 Concentration of PB-HAP compound In Pork ............ ............ ............ . . 20

5.1.1 Fraction of Plant Type i Grown on Contaminated Soil and Eaten by the Animal (Swine)

(Fi) ............ ............ ............ ............ ............ ..... 21

5.1.2 Quantity of Plant Type i Eaten by the Animal (Swine) Each Day (Qpi) ............ 21

5.1.3 Concentration of PB-HAP compound in Plant Type i Eaten by the Animal (Swine) (Pi)

............ ............ ............ ............ ............ ........ 22

5.1.4 Quantity of Soil Eaten by the Animal (Swine) Each Day (Qs) ............ ....... 22

5.1.5 Average Soil Concentration Over Exposure Duration (Cs) ............ ......... 22

5.1.6 Soil Bioavailability Factor (Bs) ............ ............ ............ ....... 22

5.1.7 Metabolism Factor (MF) ............ ............ ............ ............ 22

6.0 Calculation of PB-HAP Compound Concentrations in Chicken and Eggs ............ .... 22
6.1 Concentration of PB-HAP compound in Chicken and Eggs ............ ............ ... 23

6.1.1 Fraction of Plant Type i Grown on Contaminated Soil and Eaten by the Animal

(Chicken)(Fi) ............ ............ ............ ............ ......... 23

6.1.2 Quantity of Plant Type i Eaten by the Animal (Chicken) Each Day (Qpi) .......... 23

6.1.3 Concentration of PB-HAP compound in Plant Type i Eaten by the Animal (Chicken) (Pi)

............ ............ ............ ............ ............ ........ 24

6.1.4 Quantity of Soil Eaten by the Animal (Chicken) Each Day (Qs) ............ ..... 24

6.1.5 Average Soil Concentration Over Exposure Duration (Cs) ............ ......... 24

6.1.6 Soil Bioavailability Factor (Bs) ............ ............ ............ ....... 24

7.0 Calculation of PB-HAP Compound Concentrations in Drinking Water and Fish ........... 24

7.1 Total PB-HAP compound Load to the Water Body (LT) ............ ............ ...... 26

7.1.1 Total (Wet and Dry) Particle Phase and Vapor Phase PB-HAP compound Direct

Deposition Load to Water Body (LDEP) ............ ............ ............ . 26

7.1.2 Vapor Phase PB-HAP compound Diffusion Load to Water Body (Ldif) ............ 27

7.1.3 Runoff Load from Impervious Surfaces (LRI) ............ ............ ........ 27

7.1.4 Runoff Load from Pervious Surfaces (LR) ............ ............ ........... 28

7.1.5 Soil Erosion Load (LE) ............ ............ ............ ............ . . 29

7.2 Universal Soil Loss Equation - USLE ............ ............ ............ ........ 29

7.3 Sediment Delivery Ratio (SD) ............ ............ ............ ............ . . 30

7.4 Total Water Body PB-HAP compound Concentration (Cwtot) ............ ............ . . 30

7.4.1 Fraction of Total Water Body PB-HAP compound Concentration in the Water Column

(fwc) and Benthic Sediment (fbs) ............ ............ ............ ....... 31

7.4.2 Overall Total Water Body PB-HAP compound Dissipation Rate Constant (kwt) ..... 33

7.4.3 Water Column Volatilization Rate Constant (kv) ............ ............ ...... 33

7.4.4 Overall PB-HAP compound Transfer Rate Coefficient (Kv) ............ ......... 34

7.4.5 Liquid Phase Transfer Coefficient (KL) ............ ............ ............ . 35

7.4.6 Gas Phase Transfer Coefficient (KG) ............ ............ ............ ... 36

7.4.7 Benthic Burial Rate Constant (kb) ............ ............ ............ ..... 36

7.4.8 Total PB-HAP compound Concentration in Water Column (Cwctot) ............ ... 38

7.4.9 Dissolved Phase Water Concentration (Cdw) ............ ............ ......... 38

7.4.10 PB-HAP compound Concentration Sorbed to Bed Sediment (Csb) ............ .... 39

7.5 Concentration of PB-HAP compound in Fish (Cfish) ............ ............ .......... 39

7.5.1 Fish Concentration (Cfish) from Bioconcentration Factors Using Dissolved Phase Water

Concentration ............ ............ ............ ............ ......... 40

7.5.2 Fish Concentration (Cfish) from Bioaccumulation Factors Using Dissolved Phase Water 

Concentration ............ ............ ............ ............ ......... 40

7.5.3 Fish Concentration (Cfish) from Biota-To-Sediment Accumulation Factors Using PB-HAP

compound Sorbed to Bed Sediment ............ ............ ............ .... 40

8.0 Concentrations of Dioxins in Breast Milk ............ ............ ............ ..... 41

References ............ ............ ............ ............ ............ ............ 42

April 2004 Page K-1

1.0 Introduction

This Appendix describes equations used by some multimedia models to estimate media

concentrations for the recommended exposure scenarios presented in Part III. Most risk

assessments will use a multimedia fate and transport model to perform these calculations; the

particular equations used in a given model may differ slightly from those presented here, which

are taken largely from EPA’s 1998 Peer Review Draft Human Health Risk Assessment Protocol

for Hazardous Waste Combustion Facilities, Volume I.

(1) The equations, and descriptions of the

associated parameters, are presented here simply as a general reference, and are not intended to

imply a recommendation over other equations, methods, or values for describing these processes. 

EPA’s 1998 Risk Assessment Protocol for Hazardous Waste Combustion Facilities provides a

more detailed discussion of the origin and development of each of these equations and many of

their specific parameters. It should be noted that reference made throughout this chapter to

“particle phase” is generic and made without distinction between particle and particle-bound. 

The remainder of this chapter is divided into seven sections:

• Section 2 describes the estimating media concentration equations for soils contaminated by

PB-HAP compounds.

• Section 3 describes the estimating media concentration equations used to determine PB-HAP

compound concentrations in produce.

• Sections 4 through 6 describe equations used to determine PB-HAP compound

concentrations in animal products (such as milk, beef, pork, poultry, and eggs) resulting from

animal ingestion of contaminated feed and soil.

• Section 7 describes equations used to determine PB-HAP compound concentrations in fish

through bioaccumulation (or, for some compounds, bioconcentration) from the water column,

dissolved water concentration, or bed sediment – depending on the PB-HAP compound.

• Section 8 describes equations for estimating the concentrations of doxins in breast milk.

2.0 Calculation of PB-HAP Compound Concentrations in Soil

PB-HAP compound concentrations in soil are calculated by summing the vapor phase and

particle phase deposition of PB-HAP compounds to the soil. Wet and dry deposition of particles

and vapors are considered, with dry deposition of vapors calculated from the vapor air

concentration and the dry deposition velocity. The calculation of soil concentration incorporates

a term that accounts for loss of PB-HAP compounds by several mechanisms, including leaching,

erosion, runoff, degradation (biotic and abiotic), and volatilization. These loss mechanisms all

lower the soil concentration associated with the deposition rate.

Soil concentrations may require many years to reach steady state. As a result, the equations used

to calculate the average soil concentration over the period of deposition were derived by

integrating the instantaneous soil concentration equation over the period of deposition. For

carcinogenic PB-HAP compounds, EPA (1998)(1) recommends using two variations of the

equation (average soil concentration over exposure duration). One form should be used if the

exposure duration is greater than or equal to the operating lifetime of the emission source(s), and

the other should be used if the exposure duration is less than the operating lifetime of the

emission source(s).
April 2004 Page K-2

For noncarcinogenic PB-HAP compounds, EPA (1998)(1) recommends using the second form of

the carcinogenic equation to calculate the highest annual average PB-HAP compound soil

concentration occurring during the exposure duration. These equations are described in more

detail in Section 2.1.

Soil conditions such as pH, structure, organic matter content, and moisture content affect the

distribution and mobility of PB-HAP compounds. Loss of PB-HAP compounds from the soil is

modeled by using rates that depend on the physical and chemical characteristics of the soil. 

These variables and their use are described in the following subsections, along with the

recommended equations.

2.1 Calculating Cumulative Soil Concentration (Cs)

EPA (1998)(1) recommends the use of Equations 1A, 1B, and 1C to calculate the cumulative soil

concentration (Cs).

Carcinogens:

For T2 # tD

(Equation 1A)

For T1 < tD < T2

(Equation 1B)

Noncarcinogens:

(Equation 1C)

where

Cs = Average soil concentration over exposure duration (mg PB-HAP compound/kg soil)

Ds = Deposition term (mg PB-HAP compound/kg soil/yr)

T1 = Time period at the beginning of emissions (yr)

ks = PB-HAP compound soil loss constant due to all processes (yrG1)

tD = Time period over which deposition occurs (time period of emissions) (yr)

CstD = Soil concentration at time tD (mg/kg)

T2 = Length of exposure duration (yr)
April 2004 Page K-3

EPA (1998)(1) recommends Equation 1C when an exposure duration that is less than or equal to

the operating lifetime of the emission source(s) (T2 # tD); when an exposure duration greater

than the operating lifetime of the emissions source(s) (T1 < tD < T2), Equation 1B is

recommended. For noncarcinogenic PB-HAP compounds, Equation 1C is recommended.

The PB-HAP compound soil concentration averaged over the exposure duration, represented by

Cs, can be used for carcinogenic compounds, where risk is averaged over the lifetime of an

individual. Because the hazard quotient associated with noncarcinogenic PB-HAP compounds is

based on a threshold dose rather than a lifetime exposure, the highest annual average PB-HAP

compound soil concentration occurring during the exposure duration period is recommended to 

be used for noncarcinogenic PB-HAP compounds. The highest annual average PB-HAP

compound soil concentration, CstD, will typically occur at the end of the operating life of the

emission source(s).

EPA (1998) (1) recommends using the highest 1-year annual average soil concentration,

determined by using Equation 1C, to evaluate risk from noncarcinogenic PB-HAP compounds.

2.2 Calculating the PB-HAP compound Soil Loss Constant (ks)

Organic and inorganic PB-HAP compounds may be lost from the soil by several processes that

may or may not occur simultaneously. The rate at which a PB-HAP compound is lost from the

soil is known as the soil loss constant (ks). The constant ks is determined by using the soil’s

physical, chemical, and biological characteristics to consider the loss resulting from leaching,

runoff, erosion, biotic and abiotic degradation, and volatilization. EPA (1998)(1) recommends

that Equation 2 be used to calculate the PB-HAP compound soil loss constant (ks).

(Equation 2)

where

ks = PB-HAP compound soil loss constant due to all processes (yrG1)

ksg = PB-HAP compound loss constant due to biotic and abiotic degradation (yrG1)

kse = PB-HAP compound loss constant due to soil erosion (yrG1)

ksr = PB-HAP compound loss constant due to surface runoff (yrG1)

ksl = PB-HAP compound loss constant due to leaching (yrG1)

ksv = PB-HAP compound loss constant due to volatilization (yrG1)

As highlighted in Section 2.1, the use of Equation 2 in Equations 1A and 1B assumes that PBHAP compound loss can be defined by using first-order reaction kinetics. First-order reaction

rates depend on the concentration of one reactant.(2) The loss of a PB-HAP compound by a firstorder process depends only on the concentration of the PB-HAP compound in the soil, and a

constant fraction of the PB-HAP compound is removed from the soil over time. Those processes

that apparently exhibit first-order reaction kinetics without implying a mechanistic dependence

on a first-order loss rate are termed “apparent first-order” loss rates.(3) The assumption that PBHAP compound loss follows first-order reaction kinetics may be an oversimplification because –

at various concentrations or under various environmental conditions – the loss rates from soil

systems will resemble different kinetic expressions. However, at low concentrations, a
April 2004 Page K-4

first-order loss constant may be adequate to describe the loss of the PB-HAP compound from soil

(EPA 1990)(4).

PB-HAP compound loss in soil can also follow zero or second-order reaction kinetics. 

Zero-order reaction kinetics are independent of reactant concentrations (Bohn, McNeal, and

O’Connor 1985).(2) Zero-order loss rates describe processes in which the reactants are present at

very high concentrations. Under zero-order kinetics, a constant amount of a PB-HAP compound

is lost from the soil over time, independent of its concentration. Processes that follow

second-order reaction kinetics depend on the concentrations of two reactants or the concentration

of one reactant squared (Bohn, McNeal, and O’Connor 1985)(2) . The loss constant of a PB-HAP

compound following a second-order process can be contingent on its own concentration, or on

both its concentration and the concentration of another reactant, such as an enzyme or catalyst.

Because PB-HAP compound loss from soil depends on many complex factors, it may be difficult

to model the overall rate of loss. In addition, because the physical phenomena that cause PBHAP compound loss can occur simultaneously, the use of Equation 2 may also overestimate loss

rates for each process (Valentine 1986).(5) When possible, the common occurrence of all loss

processes should be taken into account. Combined rates of soil loss by these processes can be

derived experimentally; values for some PB-HAP compounds are presented in EPA (1986).(6)

Sections 2.2.1 through 2.2.5 discuss issues associated with the calculation of the ksl, kse, ksr, ksg,

and ksv variables.

2.2.1 PB-HAP compound Loss Constant Due to Biotic and Abiotic Degradation (ksg)

Soil losses resulting from biotic and abiotic degradation (ksg) are determined empirically from

field studies and should be addressed in the literature (EPA 1990).(4) Lyman et al. (1982)(7) states

that degradation rates can be assumed to follow first order kinetics in a homogenous medium. 

Therefore, the half-life of a compound can be related to the degradation rate constant. Ideally,

ksg is the sum of all biotic and abiotic rate constants in the soil media. Therefore, if the half-life

of a compound (for all of the mechanisms of transformation) is known, the degradation rate can

be calculated. However, literature sources do not provide sufficient data for all such

mechanisms, especially for soil. EPA (1994a)(8) recommends that ksg values for all PB-HAP

compounds other than polycyclic organic matter (specifically 2,3,7,8-TCDD) should be set equal

to zero. EPA (1998) (1) presents EPA recommended values for this compound-specific variable.

The rate of biological degradation in soils depends on the concentration and activity of the

microbial populations in the soil, the soil conditions, and the PB-HAP compound concentration

(Jury and Valentine 1986).(9) First-order loss rates often fail to account for the high variability of

these variables in a single soil system. However, the use of simple rate expressions may be

appropriate at low chemical concentrations (e.g., nanogram per kilogram soil) at which a

first-order dependence on chemical concentration may be reasonable. The rate of biological

degradation is PB-HAP compound-specific, depending on the complexity of the PB-HAP

compound and the usefulness of the PB-HAP compound to the microorganisms. Some

substrates, rather than being used by the organisms as a nutrient or energy source, are simply

degraded with other similar PB-HAP compounds, which can be further utilized. Environmental

and PB-HAP compound-specific factors that may limit the biodegradation of PB-HAP

compounds in the soil environment (Valentine and Schnoor 1986)(10) include (1) availability of
April 2004 Page K-5

the PB-HAP compound, (2) nutrient limitations, (3) toxicity of the PB-HAP compound, and (4)

inactivation or nonexistence of enzymes capable of degrading the PB-HAP compound.

Chemical degradation of organic compounds can be a significant mechanism for removal of PBHAP compounds in soil (EPA 1990).

(4) Hydrolysis and oxidation-reduction reactions are the

primary chemical transformation processes occurring in the upper layers of soils (Valentine

1986).

(5) General rate expressions describing the transformation of some PB-HAP compounds by

all non-biological processes are available, and these expressions are helpful when division into

component reactions is not possible. 

Hydrolysis in aqueous systems is characterized by three processes: acid-catalyzed, basecatalyzed, and neutral reactions. The overall rate of hydrolysis is the sum of the first-order rates

of these processes (Valentine 1986).

(5) In soil systems, sorption of the PB-HAP compound can

increase, decrease, or not affect the rate of hydrolysis, as numerous studies cited in Valentine

(1986)(5) have shown. The total rate of hydrolysis in soil can be predicted by adding the rates in

the soil and water phases, which are assumed to be first-order reactions at a fixed pH (Valentine

1986).(5) Methods for estimating these hydrolysis constants are described by Lyman et al.

(1982).(7) 

Organic and inorganic compounds also undergo oxidation-reduction (redox) reactions in the soil

(Valentine 1986).(5) Organic redox reactions involve the exchange of oxygen and hydrogen

atoms by the reacting molecules. Inorganic redox reactions may involve the exchange of atoms

or electrons by the reactants. In soil systems where the identities of oxidant and reductant species

are not specified, a first-order rate constant can be obtained for describing loss by redox reactions

(Valentine 1986).(5) Redox reactions involving metals may promote losses from surface soils by

making metals more mobile (e.g., leaching to subsurface soils).

2.2.2 PB-HAP compound Loss Constant Due to Soil Erosion (kse)

EPA (1998) (1) recommends that the constant for the loss of soil resulting from erosion (kse) is

recommended to be set equal to zero in most cases. If soil erosion is a significant issue in the

assessment area, EPA (1993b)(11) recommends the use of Equation 3 to calculate the constant for

soil loss resulting from erosion (kse).

(Equation 3)

where

kse = PB-HAP compound soil loss constant due to soil erosion

0.1 = Units conversion factor (1,000 g-kg/10,000 cm2-m2)

Xe = Unit soil loss (kg/m2-yr)

SD = Sediment delivery ratio (unitless)

ER = Soil enrichment ratio (unitless)

Kds = Soil-water partition coefficient (mL water/g soil)

BD = Soil bulk density (g soil/cm3 soil)

Zs = Soil mixing zone depth (cm)

2sw = Soil volumetric water content (mL water/cm3 soil)
April 2004 Page K-6

Unit soil loss (Xe) is calculated by using the Universal Soil Loss Equation (USLE) (See Section

7.2). Soil bulk density (BD) is described in Section 2.4.2. Soil volumetric water content (2sw) is

described in Section 2.5.4.

For additional information on addressing kse, EPA (1998)(1) recommends consulting the

methodologies described in EPA NCEA document, Methodology for Assessing Health Risks

Associated with Multiple Pathways of Exposure to Combustor Emissions (EPA 1998)(12).

2.2.3 PB-HAP compound Loss Constant Due to Runoff (ksr)

EPA (1998)(1) recommends that Equation 4 be used to calculate the constant for the loss of soil

resulting from surface runoff (ksr).

(Equation 4)

where

ksr = PB-HAP compound loss constant due to runoff (yrG1)

RO = Average annual surface runoff from pervious areas (cm/yr)

2sw = Soil volumetric water content (mL water/cm3 soil)

Zs = Soil mixing zone depth (cm)

Kds = Soil-water partition coefficient (mL water/g soil)

BD = Soil bulk density (g soil/cm3 soil)

Soil bulk density (BD) is described in Section 2.5.2. Soil volumetric water content (2sw) is

described in Section 2.5.4.

2.2.4 PB-HAP compound Loss Constant Due to Leaching (ksl)

Losses of soil PB-HAP compounds due to leaching (ksl) depend on the amount of water available

to generate leachate and soil properties such as bulk density, soil moisture, soil porosity, and soil

sorption properties. EPA (1998)(1) recommends that Equation 5 be used to calculate the PB-HAP

compound loss constant due to leaching (ksl) to account for runoff.

(Equation 5)

where

ksl = PB-HAP compound loss constant due to leaching (yrG1)

P = Average annual precipitation (cm/yr)

I = Average annual irrigation (cm/yr)

RO = Average annual surface runoff from pervious areas (cm/yr)

Ev = Average annual evapotranspiration (cm/yr)

2sw = Soil volumetric water content (mL water/cm3 soil)
April 2004 Page K-7

Zs = Soil mixing zone depth (cm)

Kds = Soil-water partition coefficient (cm3 water/g soil)

BD = Soil bulk density (g soil/cm3 soil)

The average annual volume of water (P + I - RO - Ev) available to generate leachate is the mass

balance of all water inputs and outputs from the area under consideration. These variables are

described in Section 2.5.3. Soil bulk density (BD) is described in Section 2.5.2. Soil volumetric

water content (2sw) is described in Section 2.5.4. 

2.2.5 PB-HAP compound Loss Constant Due to Volatilization (ksv)

Semi-volatile and volatile PB-HAP compounds emitted in high concentrations may become

adsorbed to soil particles and exhibit volatilization losses from soil. The loss of a PB-HAP

compound from the soil by volatilization depends on the rate of movement of the PB-HAP

compound to the soil surface, the chemical vapor concentration at the soil surface, and the rate at

which vapor is carried away by the atmosphere (Jury 1986).(13)

EPA (1998)(1) recommends that in cases where high concentrations of volatile organic

compounds are expected to be present in the soil that Equation 6A be used to calculate the

constant for the loss of soil resulting from volatilization (ksv).

(Equation 6A)

where

ksv = PB-HAP compound loss constant due to volatization (yrG1)

3.1536 × 107 = Units conversion factor (s/yr)

H = Henry’s Law constant (atm-m3/mol)

Zs = Soil mixing zone depth (cm)

Kds = Soil-water partition coefficient (mL/g)

R = Universal gas constant (atm-m3/mol-K)

Ta = Ambient air temperature (K) = 298.1 K

BD = Soil bulk density (g soil/cm3 soil) = 1.5 g/cm3

Da = Diffusivity of PB-HAP compound in air (cm2/s)

2sw = Soil volumetric water content (mL/cm3 soil) = 0.2 mL/cm3

Dsoil = Solids particle density (g/cm3) = 2.7 g/cm3

The gas-phase mass transfer coefficient, Kt, based on general soil properties, can also be written

as follows (Hillel 1980; Miller and Gardiner 1998)(14):

(Equation 6B)

where
April 2004 Page K-8

Kt = Gas phase mass transfer coefficient (cm/s)

Zs = Soil mixing zone depth (cm)

Da = Diffusivity of PB-HAP compound in air (cm2/s) 

2v = Soil void fraction (cm3/cm3)

The soil void fraction (2v) is the volumetric fraction of a soil that does not contain solids or water

and can be expressed as:

(Equation 6C)

where

2v = Soil void fraction (cm3/cm3)

2sw = Soil volumetric water content (mL water/cm3 soil) = 0.2 mL/cm3

BD = Soil bulk density (g/cm3) = 1.5 g/cm3

Dsoil = Solids particle density (g/cm3) = 2.7 g/cm3

The expression containing bulk density (BD) divided by solids particle density (Dsoil) gives the

volume of soil occupied by pore space or voids (Miller and Gardiner 1998).(14) Soil bulk density

is affected by the soil structure, such as looseness or compaction of the soil, depending on the

water and clay content of the soil (Hillel 1980)(14) ; a range of 0.83 to 1.84 was originally cited in

Hoffman and Baes (1979).(15) A default soil bulk density value of 1.5 g/cm3 is recommended

based on a mean value for loam soil from Carsel et al. (1988).

(16) Blake and Hartge (1996)(17) and

Hillel (1980)(14) both suggests that the mean density of solid particles is about 2.7 gm/cm3. The

soil water content depends on both the available water and the soil structure of a particular soil. 

Values for 2sw range from 0.03 to 0.40 mL/cm3 depending on soil type (Hoffman and Baes

1979).(15) The lower values are typical of sandy soils, which cannot retain much water; the

higher values are typical of soils such as clay or loam soils which can retain water. A mid-point

default value of 0.2 mL water/cm3 soil is recommended as a default in the absence of site-specific

information. However, since the soil water content of soil is unique for each soil type, sitespecific information is highly recommended.

2.3 Calculating the Deposition Term (Ds)

EPA (1998)(1) recommends that Equation 7 be used to calculate the deposition term (Ds).

(Equation 7)

where

Ds = Deposition term (mg PB-HAP compound/kg soil/yr)

100 = Units conversion factor (mg-m2/kg-cm2)

Q = PB-HAP compound emission rate (g/s)

Zs = Soil mixing zone depth (cm)
April 2004 Page K-9

BD = Soil bulk density (g soil/cm3 soil)

Fv = Fraction of PB-HAP compound air concentration in vapor phase (unitless)

Dydv = Unitized yearly average dry deposition from vapor phase (s/m2-yr)

Dywv = Unitized yearly average wet deposition from vapor phase (s/m

2

-yr)

Dydp = Unitized yearly average dry deposition from particle phase (s/m2-yr)

Dywp = Unitized yearly average wet deposition from particle phase (s/m2-yr)

2.4 Universal Soil Loss Equation (USLE)

EPA (1998)(1) recommends that the universal soil loss equation (USLE) be used to calculate the

unit soil loss (Xe). This equation is further described in Section 7.2.

2.5 Site-Specific Parameters for Calculating Cumulative Soil Concentration

Calculating average soil concentration over the exposure duration (Cs) requires the use of

site-specific parameters including the following:

• Soil mixing zone depth (Zs)

• Soil bulk density (BD)

• Available water (P + I - RO - Ev)

• Soil volumetric water content (qsw)

Determination of values for these parameters is further described in the following subsections.

2.5.1 Soil Mixing Zone Depth (Zs)

When exposures to PB-HAP compounds in soils are modeled, the depth of contaminated soils is

important in calculating the appropriate soil concentration. PB-HAP compounds deposited onto

soil surfaces may be moved into lower soil profiles by tilling, whether manually in a garden or

mechanically in a large field.

EPA (1998)(1) recommends the following values for the soil mixing zone depth (Zs):

• 2 cm for untilled soils; and

• 20 cm for tilled soils.

The assumption made to determine the value of Zs may affect the outcome of the risk assessment,

because soil concentrations that are based on soil depth are used to calculate exposure via several

pathways: (1) ingestion of plants contaminated by root uptake; (2) direct ingestion of soil by

humans, cattle, swine, or chicken; and (3) surface runoff into water bodies.

2.5.2 Soil Dry Bulk Density (BD)

Soil dry bulk density (BD) is the ratio of the mass of soil to its total volume. EPA (1998)(1)

recommends the value of 1.50 g/cm3 for the soil dry bulk density (BD). EPA (1994c)(18)

recommended that wet soil bulk density be determined by weighing a thin-walled, tube soil

sample (e.g., a Shelby tube) of known volume and subtracting the tube weight (ASTM Method
April 2004 Page K-10

D2937).(19) Moisture content can then be calculated (ASTM Method 2216)(20) to convert wet soil

bulk density to dry soil bulk density.

2.5.3 Available Water (P + I - RO - Ev)

The average annual volume of water available (P + I - RO - Ev) for generating leachate is the

mass balance of all water inputs and outputs from the area under consideration. A wide range of

values for these site-specific parameters may apply in the various EPA regions.

The average annual precipitation (P), irrigation (I), runoff (RO), and evapotranspiration (Ev) rates

and other climatological data may be obtained from either data recorded on site or from the

Station Climatic Summary for a nearby airport. 

Meteorological variables such as the evapotranspiration rate (Ev) and the runoff rate (RO) may

also be found in resources such as Geraghty, Miller, van der Leeden, and Troise (1973).(21)

Surface runoff may also be estimated by using the Curve Number Equation developed by the

U.S. Soil Conservation Service (EPA 1990).(4) EPA (1985)(22) cited isopleths of mean annual

cropland runoff corresponding to various curve numbers developed by Stewart, Woolhiser,

Wischmeier, Caro, and Frere (1975).(23) Curve numbers are assigned to an area on the basis of

soil type, land use or cover, and the hydrologic conditions of the soil (EPA 1990).(4)

Using these different references, however, introduces uncertainties and limitations. For example,

Geraghty, Miller, van der Leeden, and Troise (1973)(21) presented isopleths for annual surface

water contributions that include interflow and ground water recharge. As noted in EPA

(1994a)(8), these values are recommended to be adjusted downward to reflect surface runoff only. 

EPA (1994a)(8) recommended that these values be reduced by 50 percent.

2.5.4 Soil Volumetric Water Content (2sw)

The soil volumetric water content (2sw) depends on the available water and the soil structure. A

wide range of values for these variables may apply in the various EPA regions. EPA (1998)(1)

recommends a value for 2sw of 0.2 ml/cm3.

3.0 Calculation of PB-HAP Compound Concentrations in Produce

Indirect exposure resulting from ingestion of produce depends on the total concentration of PBHAP compounds in the leafy, fruit, and tuber portions of the plant. Because of general

differences in contamination mechanisms, consideration of indirect exposure separates produce

into two broad categories: aboveground produce and belowground produce. In addition,

aboveground produce can be further subdivided into exposed and protected aboveground produce

for consideration of contamination as a result of indirect exposure. 

Aboveground Produce

Aboveground exposed produce is assumed to be contaminated by three possible mechanisms:

• Direct deposition of particles—wet and dry deposition of particle phase PB-HAP

compounds on the leaves and fruits of plants (Section 3.1).
April 2004 Page K-11

• Vapor transfer—uptake of vapor phase PB-HAP compounds by plants through their foliage

(Section 3.2).

• Root uptake—root uptake of PB-HAP compounds available from the soil and their transfer

to the aboveground portions of the plant (Section 3.3).

The total PB-HAP compound concentration in aboveground exposed produce is calculated as a

sum of contamination occurring through all three of these mechanisms. However, edible

portions of aboveground protected produce, such as peas, corn, and melons, are covered by a

protective covering; hence, they are protected from contamination through deposition and vapor

transfer. Therefore, root uptake of PB-HAP compounds is the primary mechanism through

which aboveground protected produce becomes contaminated (Section 3.3). 

Belowground Produce

For belowground produce, contamination is assumed to occur only through one mechanism –

root uptake of PB-HAP compounds available from soil (Section 3.3). Contamination of

belowground produce via direct deposition of particles and vapor transfer are not considered

because the root or tuber is protected from contact with contaminants in the vapor phase.

3.1 Aboveground Produce Concentration Due to Direct Deposition (Pd)

EPA (1998)(1) recommends the use of Equation 8 to calculate PB-HAP compound concentration

in exposed and aboveground produce due to direct deposition.

(Equation 8)

where

Pd = Plant (aboveground produce) concentration due to direct (wet and dry) deposition (mg

PB-HAP compound/kg DW)

1,000 = Units conversion factor (mg/g)

Q = PB-HAP compound emission rate (g/s)

Fv = Fraction of PB-HAP compound air concentration in vapor phase (unitless)

Dydp = Unitized yearly average dry deposition from particle phase (s/m2-yr)

Fw = Fraction of PB-HAP compound wet deposition that adheres to plant surfaces

(unitless)

Dywp = Unitized yearly wet deposition from particle phase (s/m2-yr)

Rp = Interception fraction of the edible portion of plant (unitless)

kp = Plant surface loss coefficient (yrG1)

Tp = Length of plant exposure to deposition per harvest of the edible portion of the ith

plant group (yr)

Yp = Yield or standing crop biomass of the edible portion of the plant (productivity) (kg

DW/m2)
April 2004 Page K-12

3.1.1 Interception Fraction of the Edible Portion of Plant (Rp)

EPA (1998)(1) recommends the use of the weighted average Rp value of 0.39 as a default Rp value

because it represents the most current parameters including standing crop biomass and relative

ingestion rates.

3.1.2 Plant Surface Loss Coefficient (kp)

EPA (1998)(1) recommends use of a plant surface loss coefficient (kp) value of 18. The primary

uncertainty associated with this variable is that the calculation of kp does not consider chemical

degradation processes. However, information regarding chemical degradation of contaminants

on plant surfaces is limited. The inclusion of chemical degradation processes would result in

decreased half-life values and thereby increase kp values. Note that effective plant concentration

decreases as kp increases. Therefore, use of a kp value that does not consider chemical

degradation processes is protective.

3.1.3 Length of Plant Exposure to Deposition per Harvest of Edible Portion of Plant (Tp)

This value represents the time required from when a plant first emerges until harvest. EPA

(1998)(1) recommends using a Tp value of 0.164 year as the best available default value. The

primary uncertainty associated with the use of this value is that it is based on the growing season

for hay rather than aboveground produce. The average period between successive hay harvests

(60 days) may not reflect the length of the growing season or the period between successive

harvests for aboveground produce at specific sites. To the extent that information documenting

the growing season or period between successive harvests for aboveground produce is available,

this information may be used to estimate a site-specific Tp value. Calculated plant

concentrations will be affected most if the site-specific value of Tp is significantly less than 60

days.

3.1.4 Standing Crop Biomass (Productivity) (Yp)

EPA (1998)(1) recommends the use of the weighted average Yp value of 2.24 as a default Yp

value based on this value representing the most complete and thorough information available. 

The primary uncertainty associated with this variable is that the harvest yield (Yh) and area

planted (Ah) may not reflect site-specific conditions. To the extent to which site-specific

information is available, the magnitude of the uncertainty introduced by the default Yp value can

be estimated.

3.2 Aboveground Produce Concentration Due to Air-to-Plant Transfer (Pv)

The methodology used to estimate PB-HAP compound concentration in exposed and

aboveground produce due to air-to-plant transfer (Pv) considers limitations of PB-HAP

compounds concentrations to transfer from plant surfaces to the inner portions of the plant. 

These limitations result from mechanisms responsible for inhibiting the transfer of the lipophilic

PB-HAP compound (e.g., the shape of the produce) and the removal of the PB-HAP compounds

from the edible portion of the produce (e.g., washing, peeling, and cooking). EPA (1998)(1) 

recommends the use of Equation 9 to calculate aboveground produce concentration due to

air-to-plant transfer (Pv).
April 2004 Page K-13

(Equation 9)

where

Pv = Concentration of PB-HAP compound in the plant resulting from air-to-plant transfer

(:g PB-HAP compound/g DW)

Q = PB-HAP compound emission rate (g/s)

Fv = Fraction of PB-HAP compound air concentration in vapor phase (unitless)

Cyv = Unitized yearly average air concentration from vapor phase (:g-s/g-m3)

Bvag = PB-HAP compound air-to-plant biotransfer factor ([mg PB-HAP compound/g DW

plant]/[mg PB-HAP compound/g air]) (unitless)

VGag = Empirical correction factor for aboveground produce (unitless)

Da = Density of air (g/m3)

As discussed below in Section 3.2.1, the parameter VGag is dependent on lipophilicity of the PBHAP compound, and assigned a value of 0.01 for lipophilic PB-HAP compounds (log Kow greater

than 4) or a value of 1.0 for PB-HAP compounds with a log Kow less than 4.

Empirical Correction Factor for Aboveground Produce (VGag)

The parameter VGag has been incorporated into Equation 9 to address the potential

overestimation for lipophilic PB-HAP compounds to be transferred to the inner portions of

bulky produce, such as apples. Because of the protective outer skin, size, and shape of bulky

produce, transfer of lipophilic PB-HAP compounds (log Kow greater than 4) to the center of the

produce is not as likely as for non-lipophilic PB-HAP compounds and, as a result, the inner

portions will be less affected. EPA (1998)(1) recommends the following empirical VGag values

for aboveground produce:

• 0.01 for lipophilic PB-HAP compounds (log Kow greater than 4); and

• 1.0 for PB-HAP compounds with a log Kow less than 4 (these PB-HAP compounds are

assumed pass more easily through the skin of produce).

Uncertainty may be introduced by the assumption of VGag values for leafy vegetables (such as

lettuce) and for legumes (such as snap beans). Underestimation may be introduced by assuming

a VGag value of 0.01 for legumes and leafy vegetables because these species often have a higher

ratio of surface area to mass than other bulkier fruits and fruiting vegetables, such as tomatoes.

3.3 Produce Concentration Due to Root Uptake (Pr)

Root uptake of contaminants from soil may also result in PB-HAP compound concentrations in

aboveground exposed produce, aboveground protected produce, and belowground produce. EPA

(1998)(1) recommends the use of Equations 10A and 10B to calculate PB-HAP compound

concentration aboveground and belowground produce due to root uptake (Pr).
April 2004 Page K-14

Exposed and protected aboveground produce:

(Equation 10A)

Belowground produce:

(Equation 10B)

where

Pr = Concentration of PB-HAP compound in produce due to root uptake (mg/kg)

Br = Plant-soil bioconcentration factor for produce (unitless)

VGrootveg = Empirical correction factor for belowground produce (unitless)

Kds = Soil-water partition coefficient (L/kg)

Cs = Average soil concentration over exposure duration (mg PB-HAP compound/kg

soil)

RCF = Root concentration factor (unitless)

Equation 10A is appropriate for evaluation of exposed and protected aboveground produce;

however, it may not be appropriate for soil-to-belowground plant transfers. For belowground

produce, Equation 10B includes a root concentration factor (RCF) developed by Briggs et al.

(1982).(24) RCF is the ratio of PB-HAP compound concentration in the edible root to the PBHAP compound concentration in the soil water. Since Briggs et al. (1982)(24) conducted their

experiments in a growth solution, the PB-HAP compound soil concentration (Cs) must be

divided by the PB-HAP compound-specific soil-water partition coefficient (Kds ) (EPA

1994b).(25)

Similar to VGag and as discussed in Section 3.2.1, VGrootveg is based on the lipophilicity of the PBHAP compound. EPA (1998)(1) recommends the following empirical values for VGrootveg:

• 0.01 for lipophilic PB-HAP compounds (log Kow greater than 4) based on root vegetables like

carrots and potatoes; and

• 1.0 for PB-HAP compounds with a log Kow less than 4.

4.0 Calculation of PB-HAP Compound Concentrations in Beef and Dairy Products

PB-HAP compound concentrations in beef tissue and milk products are estimated on the basis of

the amount of PB-HAP compounds that cattle are assumed to consume through their diet. The

cattle's diet is assumed to consist of forage (primarily pasture grass and hay); silage (forage that

has been stored and fermented), and grain. Additional contamination may occur through the

cattle’s ingestion of soil. The total PB-HAP compound concentration in the feed items (e.g.,

forage, silage, and grain) is calculated as a sum of contamination occurring through the following

mechanisms:

• Direct deposition of particles—wet and dry deposition of particle phase PB-HAP

compounds onto forage and silage (Section 4.1).
April 2004 Page K-15

• Vapor transfer—uptake of vapor phase PB-HAP compounds by forage and silage through

foliage (Section 4.2).

• Root uptake—root uptake of PB-HAP compounds available from the soil and their transfer

to the aboveground portions of forage, silage, and grain (Section 4.3).

Feed items consumed by animals can be classified as exposed and protected, depending on

whether it has a protective outer covering. Because the outer covering on the protected feed acts

as a barrier, it is assumed that there is negligible contamination of protected feed through

deposition of particles and vapor transfer. In this analysis, grain is classified as protected feed. 

As a result, grain contamination is assumed to occur only through root uptake. Contamination of

exposed feed items, including forage and silage, is assumed to occur through all three

mechanisms.

The amount of grain, silage, forage, and soil consumed is assumed to vary between dairy and

beef cattle. Sections 4.4 (beef) and 4.5 (dairy) describe methods for estimating consumption

rates and subsequent PB-HAP compound concentrations in cattle. EPA (1998)(1) recommends

that 100 percent of the plant materials eaten by cattle be assumed to have been grown on soil

contaminated by emission sources. Therefore, 100 percent of the feed items consumed are

assumed to be contaminated. 

4.1 Forage and Silage Concentrations Due to Direct Deposition (Pd)

PB-HAP compound concentrations in forage and silage result from wet and dry deposition onto

exposed plant surfaces; similar to aboveground produce (Section 3.1). Equation 8, described in 

Section 3.1, is recommended for calculation of PB-HAP compound concentrations resulting from

direct deposition onto plant surfaces of leafy plants and exposed produce (Pd). Therefore, EPA

(1998)(1) recommends that Equation 8 also be used in calculating forage and silage

concentrations due to direct deposition.

4.1.1 Interception Fraction of the Edible Portion of Plant (Rp)

EPA (1998)(1) recommends use of the Rp value of 0.5 for forage and the Rp value of 0.46 for

silage. Note that the empirical relationships used to develop the default values for silage may not

accurately represent site-specific silage types. However, the range of empirical constants used to

develop the default value for forage is fairly small, and therefore the use of the midpoint should

not significantly affect the Rp value and the resulting estimate of plant PB-HAP compound

concentration.

4.1.2 Plant Surface Loss Coefficient (kp)

Section 3.1.2 presents the recommended value for plant surface loss coefficient kp for

aboveground produce. The kp factor is derived in exactly the same manner for cattle forage and

silage, and the uncertainties of kp for cattle forage and silage are similar to its uncertainties for

aboveground produce.
April 2004 Page K-16

4.1.3 Length of Plant Exposure to Deposition per Harvest of the Edible Portion of Plant

(Tp)

As discussed in Section 3.1.3, Tp is treated as a constant, based on the average period between

successive hay harvests. This periodrepresents the length of time that aboveground vegetation

(in this case, hay) would be exposed to particle deposition before being harvested. EPA (1998)(1) 

recommends the following Tp values: 0.12 year for forage; and 0.16 year for silage. The primary

uncertainties associated with Tp are similar to those for aboveground produce, and are discussed

in Section 3.1.3.

4.1.4 Standing Crop Biomass (Productivity) (Yp)

As discussed in Section 3.1.4, the best estimate of Yp is productivity, requires consideration of

dry harvest yield (Yh) and area harvested (Ah). EPA (1998)(1) recommends that forage Yp be

calculated as a weighted average of the calculated pasture grass and hay Yp values. Weightings

are assumed to be 0.75 for forage and 0.25 for hay, based on the fraction of a year that cattle are

assumed to be pastured and eating grass (9 months per year) or not pastured and fed hay (3

months per year). The resulting value of 0.24 kg DW/m2 is recommended as the Yp for forage. 

For silage, EPA (1998)(1) recommends that a production-weighted U.S. average Yp of 0.8 kg

DW/m2 be assumed. The primary uncertainty associated with this variable is that the harvest

yield (Yh) and area planted (Ah) may not reflect site-specific conditions. To the extent that

site-specific information is available, the magnitude of the uncertainty introduced by the default

Yp value can be estimated. In addition, the weightings assumed in this discussion for the amount

of time that cattle are pastured (and foraging) or stabled (and being fed silage) should be adjusted

to reflect site-specific conditions, as appropriate.

4.2 Forage and Silage Concentrations Due to Air-to-Plant Transfer (Pv)

PB-HAP compound concentration in aboveground produce resulting from air-to-plant transfer

(Pv), is calculated by using Equation 9 (Section 3.2). Pv is calculated for cattle forage and silage

similarly to the way that it is calculated for aboveground produce. A detailed discussion of Pv is

provided in Section 3.2. Differences in VGag values for forage and silage, as compared to the

values for aboveground produce described in Section 3.2.1, are presented below in Section 4.2.1.

Empirical Correction Factor for Forage and Silage (VGag)

EPA (1998)(1) recommends the use of VGag values of 1.0 for forage and 0.5 for silage. As

discussed, the primary uncertainty associated with this variable is the lack of specific information

on the proportions of each vegetation type of which silage may consist, leading to the default

assumption of 0.5.

4.3 Forage, Silage, and Grain Concentrations Due to Root Uptake (Pr)

PB-HAP compound concentration in aboveground and belowground produce resulting from root

uptake is calculated by using Equations 10A and 10B (Section 3.3). Pr is also calculated for

cattle forage, silage, and grain in exactly the same way that it is calculated for aboveground

produce. A detailed discussion describing calculation of Pr is provided in Section 3.3.
April 2004 Page K-17

4.4 Beef Concentration Resulting from Plant and Soil Ingestion (Abeef)

EPA (1998)(1) recommends that PB-HAP compound concentration in beef tissue (Abeef) be

calculated by using Equation11. Equation 11 calculates the daily amount of a PB-HAP

compound that is consumed by cattle through the ingestion of contaminated feed items (plant)

and soil. The equation includes biotransfer and metabolism factors to transform the daily animal

intake of a PB-HAP compound (mg/day) into an animal PB-HAP compound tissue concentration

(mg PB-HAP compound/kg tissue).

(Equation 11)

where

Abeef = Concentration of PB-HAP compound in beef (mg PB-HAP compound/kg FW tissue)

Fi = Fraction of plant type i grown on contaminated soil and ingested by the animal

(cattle) (unitless)

Qpi = Quantity of plant type i eaten by the animal (cattle) per day (kg DW plant/day)

Pi = Concentration of PB-HAP compound in each plant type i eaten by the animal (cattle)

(mg/kg DW)

Qs = Quantity of soil eaten by the animal (cattle) each day (kg/day)

Cs = Average soil concentration over exposure duration (mg PB-HAP compound/kg soil)

Bs = Soil bioavailability factor (unitless)

Babeef = PB-HAP compound biotransfer factor for beef (day/kg FW tissue)

MF = Metabolism factor (unitless)

The parameters Fi, Qpi, Pi, Qs, Cs, Bs, and MF are described in Sections 4.4.1 through 4.4.7,

respectively.

4.4.1 Fraction of Plant Type i Grown on Contaminated Soil and Eaten by the Animal

(Cattle)(Fi)

EPA (1998)(1) recommends that 100 percent of the plant materials eaten by cattle be assumed to

have been grown on soil contaminated by the emission sources being evaluated and therefore

recommends a default value of 1.0 for Fi.

4.4.2 Quantity of Plant Type i Eaten by the Animal (Cattle) Each Day (Qpi)

EPA (1998)(1) recommends the following beef cattle ingestion rates of forage, silage, and grain. 

These values are based on the total daily intake rate of about 12 kg DW/day.

• Forage = 8.8 kg DW/day;

• Silage = 2.5 kg DW/day; and

• Grain = 0.47 kg DW/day.

The principal uncertainty associated with Qpi is the variability between forage, silage, and grain

ingestion rates for cattle. 
April 2004 Page K-18

4.4.3 Concentration of PB-HAP compound in Plant Type i Eaten by the Animal (Cattle)

(Pi)

The total PB-HAP compound concentration in forage, silage, and grain are recommended to be

calculated by using Equation 12. Values for Pd, Pv, and Pr can be derived for each type of feed

by using Equations 8, 17, and 10, respectively.

(Equation 12)

where

Pi = Concentration of PB-HAP compound in each plant type i eaten by the animal (mg PBHAP compound/kg DW)

Pd = Plant concentration due to direct deposition (mg PB-HAP compound/kg DW)

Pv = Plant concentration due to air-to-plant transfer (mg PB-HAP compound/kg DW)

Pr = Plant concentration due to root uptake (mg PB-HAP compound/kg DW)

4.4.4 Quantity of Soil Eaten by the Animal (Cattle) Per Day (Qs)

Additional cattle contamination occurs through ingestion of soil. EPA (1998)(1) recommends a

value of 0.5 kg/day for the quantity of soil ingested by the animal (cattle).

4.4.5 Average Soil Concentration Over Exposure Duration (Cs)

PB-HAP compound concentration in soil is recommended to be calculated as discussed in

Section 2.1, by using Equations 1A, 1B, and 1C.

4.4.6 Soil Bioavailability Factor (Bs)

The efficiency of transfer from soil may differ from efficiency or transfer from plant material for

some PB-HAP compounds. If the transfer efficiency is lower for soils, than this ratio would be

less than 1.0. If it is equal or greater than that of vegetation, the Bs value would be equal to or

greater than 1.0. Until more PB-HAP compound-specific data becomes available for this

parameter, EPA (1998)(1) recommends a default value of 1 for Bs. 

4.4.7 Metabolism Factor (MF)

The metabolism factor (MF) represents the estimated amount of PB-HAP compound that remains

in fat and muscle. EPA (1998)(1) recommends a MF of 1.0 for all PB-HAP compounds. 

Considering the recommended values for this variable, MF has no quantitative effect on Abeef.

MF applies only to mammalian species, including beef cattle, dairy cattle, and pigs. It does not

relate to metabolism in produce, chicken, or fish. In addition, since exposures evaluated in this

chapter are intake driven, the use of a metabolism factor applies only to ingestion of beef, milk,

and pork. In summary, use of a MF does not apply for direct exposures to soil or water, or to

ingestion of produce, chicken, or fish.
April 2004 Page K-19

4.5 PB-HAP compound Concentration In Milk Due to Plant and Soil Ingestion (Amilk)

Equation 11 (Section 4.4) describes the calculation of PB-HAP compound concentrations in beef

cattle (Abeef). Equation 11 can be modified to calculate PB-HAP compound milk concentrations 

(Amilk), as follows:

(Equation 13)

where

Amilk = Concentration of PB-HAP compound in milk (mg PB-HAP compound/kg milk)

Fi = Fraction of plant type i grown on contaminated soil and ingested by the animal (dairy

cattle) (unitless)

Qpi = Quantity of plant type i eaten by the animal (dairy cattle) each day (kg DW plant/day)

Pi = Concentration of PB-HAP compound in plant type i eaten by the animal (dairy cattle)

(mg/kg DW)

Qs = Quantity of soil eaten by the animal (dairy cattle) each day (kg soil/day)

Cs = Average soil concentration over exposure duration (mg PB-HAP compound/kg soil)

Bs = Soil bioavailability factor (unitless)

Bamilk = PB-HAP compound biotransfer factor for milk (day/kg WW tissue)

MF = Metabolism factor (unitless)

EPA (1998)(1) recommends the use of Equation 13 to estimate dairy cattle milk PB-HAP

compound concentration (Amilk). The discussion in Section 4.4 of the variables Fi, Qpi, Pi, Qs, Cs,

and MF for beef cattle generally applies to the corresponding variables for dairy cattle. However,

there are some differences in assumptions made for dairy cattle; these differences are

summarized in the following subsections.

4.5.1 Fraction of Plant Type i Grown on Contaminated Soil and Eaten by the Animal

(Dairy Cattle) (Fi)

The calculation of Fi for dairy cattle is identical to that for beef cattle (Section 4.4.1).

4.5.2 Quantity of Plant Type i Eaten by the Animal (Dairy Cattle) Per Day (Qpi)

As discussed in Section 4.4.2, the daily quantity of forage, silage, and grain feed consumed by

cattle is estimated for each category of feed material. However, daily ingestion rates for dairy

cattle are estimated differently than for beef cattle. The daily quantity of feed consumed by cattle

is recommended to be estimated on a dry weight basis for each category of plant feed. 

EPA (1998)(1) recommends a default total ingestion rate of 20 kg DW/day for dairy cattle,

divided among forage, silage, and grain, as follows:

• Forage = 13.2 kg DW/day;

• Silage = 4.1 kg DW/day; and

• Grain = 3.0 kg DW/day 
April 2004 Page K-20

Uncertainties associated with the estimation of Qpi include the estimation of forage, grain, and

silage ingestion rates, which will vary from site to site. The assumption of uniform

contamination of plant materials consumed by cattle also introduces uncertainty.

4.5.3 Concentration of PB-HAP compound in Plant Type i Eaten by the Animal (Dairy

Cattle) (Pi)

The estimation of Pi for dairy cattle is identical to that for beef cattle (Section 4.4.3).

4.5.4 Quantity of Soil Eaten by the Animal (Dairy Cattle) Per Day (Qs)

As discussed in Section 4.4.4, contamination of dairy cattle also results from the ingestion of

soil. EPA (1998)(1) recommends a soil ingestion rate of 0.4 kg/day for dairy cattle. Uncertainties

associated with Qs include the lack of current empirical data to support soil ingestion rates for

dairy cattle. The assumption of uniform contamination of soil ingested by cattle also adds

uncertainty.

4.5.5 Average Soil Concentration Over Exposure Duration (Cs)

The calculation of Cs for dairy cattle is the same as for beef cattle (Section 4.4.5).

4.5.6 Soil Bioavailability Factor (Bs)

The calculation of Bs for dairy cattle is the same as for beef cattle (Section 4.4.6).

4.5.7 Metabolism Factor (MF)

The recommended values for MF are identical to those recommended for beef cattle (Section

4.4.7).

5.0 Calculation of PB-HAP Compound Concentrations in Pork

PB-HAP compound concentrations in pork tissue are estimated on the basis of the amount of PBHAP compounds that swine are assumed to consume through their diet; assumed to consist of

silage and grain. Additional PB-HAP compound contamination of pork tissue may occur

through the ingestion of soil by swine.

5.1 Concentration of PB-HAP compound In Pork

Equation 11 (Section 4.4) describes the calculation of PB-HAP compound concentration in beef

cattle (Abeef). Equation 11 can be modified to calculate PB-HAP compound concentrations in

swine (Apork), as follows:

(Equation 14)

where
April 2004 Page K-21

Apork = Concentration of PB-HAP compound in pork (mg PB-HAP compound/kg FW tissue)

Fi = Fraction of plant type i grown on contaminated soil and ingested by the animal

(swine)(unitless)

Qpi

= Quantity of plant type i eaten by the animal (swine) each day (kg DW plant/day)

Pi = Concentration of PB-HAP compound in plant type i eaten by the animal (swine)

(mg/kg DW)

Qs = Quantity of soil eaten by the animal (swine) (kg/day)

Cs = Average soil concentration over exposure duration (mg PB-HAP compound/kg soil)

Bs = Soil bioavailability factor (unitless)

Bapork = PB-HAP compound biotransfer factor for pork (day/kg FW tissue)

MF = Metabolism factor (unitless)

EPA (1998)(1) recommends that Equation 14 be used to calculate PB-HAP compound pork

concentrations (Apork). The discussion in Section 4.5 of the variables Fi, Qpi, Pi, Qs, Cs and MF

for beef cattle generally applies to the corresponding variables for pork. However, different

assumptions are made for pork. These differences are summarized in the following subsections.

5.1.1 Fraction of Plant Type i Grown on Contaminated Soil and Eaten by the Animal

(Swine) (Fi)

The calculation of Fi for pork is identical to that for beef cattle (Section 4.4.1).

5.1.2 Quantity of Plant Type i Eaten by the Animal (Swine) Each Day (Qpi)

As discussed in Section 4.4.2, the daily quantity of forage, silage, and grain feed consumed by

beef cattle is estimated for each category of feed material. However, daily ingestion rates for

pork are estimated differently than for beef cattle. Because swine are not grazing animals, they

are assumed not to eat forage, and EPA (1998)(1) recommends that the daily quantity of plant

feeds (kilograms of DW) consumed by swine be estimated for each category of plant feed. 

EPA (1990)(4) and NC DEHNR (1997)(26) did not differentiate between subsistence and typical

hog farmers as for cattle. EPA (1990)(4) and NC DEHNR (1997)(26) recommended grain and

silage ingestion rates for swine as 3.0 and 1.3 kg DW/day, respectively. NC DEHNR (1997)(26) 

references EPA (1990)(4) as the source of these ingestion rates. EPA (1990)(4) reported total dry

matter ingestion rates for hogs and lactating sows as 3.4 and 5.2 kg DW/day, respectively. EPA

(1990)(4) cites Boone, Ng, and Palm (1981)(27) as the source of the ingestion rate for hogs, and

NAS (1987)(28) as the source of the ingestion rate for a lactating sow. Boone, Ng, and Palm

(1981)(27) reported a grain ingestion rate of 3.4 kg DW/day for a hog. NAS (1987)(28) reported an

average ingestion rate of 5.2 kg DW/day for a lactating sow. EPA (1990)(4) recommended using

the average of these two rates (4.3 kg DW/day). EPA (1990)(4) assumed that 70 percent of the

swine diet is grain and 30 percent silage to obtain the grain ingestion rate of 3.0 kg DW/day and

the silage ingestion rate of 1.3 kg DW/day. EPA (1990)(4) cited EPA (1982)(29) as the source of

the grain and silage dietary fractions. EPA (1995)(30) recommended an ingestion rate of 4.7

kg DW/day for a swine, referencing NAS (1987).(28) NAS (1987)(28) reported an average daily

intake of 4.36 kg DW/day for a gilt (young sow) and a average daily intake of 5.17 kg DW/day

for a sow, which averages out to 4.7 kg/DW/day. Assuming the 70 percent grain to 30 percent

silage diet noted above, estimated ingestion rates of 3.3 kg DW/day (grain) and 1.4 kg DW/day

(silage) are derived. 
April 2004 Page K-22

EPA (1998)(1) recommends the use of the following Qpi values for pork:

• Grain = 3.3 kg DW/day; and

• Silage = 1.4 kg DW/day.

Uncertainties associated with this variable include the variability of actual grain and silage

ingestion rates from site to site. Site-specific data can be used to mitigate this uncertainty. In

addition, the assumption of uniform contamination of plant materials consumed by swine

produces some uncertainty.

5.1.3 Concentration of PB-HAP compound in Plant Type i Eaten by the Animal (Swine)

(Pi)

The calculation of Pi for pork is identical to that for beef cattle (Section 4.4.3).

5.1.4 Quantity of Soil Eaten by the Animal (Swine) Each Day (Qs)

As discussed in Section 4.4.4, additional contamination of swine results from ingestion of soil. 

EPA (1998)(1) recommends the following soil ingestion rate for swine: 0.37 kg DW/day. 

Uncertainties associated with this variable include the lack of current empirical data to support

soil ingestion rates for swine, and the assumption of uniform contamination of soil ingested by

swine.

5.1.5 Average Soil Concentration Over Exposure Duration (Cs)

The calculation of Cs for pork is the same as for beef cattle (Section 4.4.5).

5.1.6 Soil Bioavailability Factor (Bs)

The calculation of Bs for pork is the same as for beef cattle (Section 4.4.6)

5.1.7 Metabolism Factor (MF)

The recommended values for MF are identical to those recommended for beef cattle (Section

4.4.7).

6.0 Calculation of PB-HAP Compound Concentrations in Chicken and Eggs

Estimates of the PB-HAP compound concentrations in chicken and eggs are based on the amount

of PB-HAP compounds that chickens consume through ingestion of grain and soil. The uptake

of PB-HAP compounds via inhalation and via ingestion of water is assumed to be insignificant

relative to other pathways. Chickens are assumed to be housed in a typical manner that allows

contact with soil; and therefore, are assumed to consume 10 percent of their diet as soil. The

remainder of the diet (90 percent) is assumed to consist of grain. Grain ingested by chickens is

assumed to have originated from the exposure scenario location; therefore, 100 percent of the

grain consumed is assumed to be contaminated. The uptake of PB-HAP compounds via

ingestion of contaminated insects and other organisms (e.g., worms, etc.), which may also
April 2004 Page K-23

contribute to the ingestion of PB-HAP compounds, is not accounted for in the equations and may

be a limitation depending on the site-specific conditions under which the chickens are raised. 

The PB-HAP compound concentration in grain is estimated by using the algorithm for

aboveground produce described in Section 3. Grain is considered to be a feed item that is

protected from deposition of particles and vapor transfer. As a result, only contamination due to

root uptake of PB-HAP compounds is considered in the calculation of PB-HAP compound

concentration in grain.

6.1 Concentration of PB-HAP compound in Chicken and Eggs

EPA (1998)(1) recommends the use of Equation 15 to calculate PB-HAP compound

concentrations in chicken and eggs. It is recommended that PB-HAP compound concentrations

in chicken and eggs be determined separately.

(Equation 15)

where

Achicken = Concentration of PB-HAP compound in chicken (mg PB-HAP compound/kg FW

tissue)

Aegg = Concentration of PB-HAP compound in eggs (mg PB-HAP compound/kg FW

tissue)

Fi = Fraction of plant type i (grain) grown on contaminated soil and ingested by the

animal (chicken)(unitless)

Qpi = Quantity of plant type i (grain) eaten by the animal (chicken) each day (kg DW

plant/day)

Pi = Concentration of PB-HAP compound in plant type i (grain) eaten by the animal

(chicken) (mg/kg DW)

Qs = Quantity of soil eaten by the animal (chicken) (kg/day)

Cs = Average soil concentration over exposure duration (mg PB-HAP compound/kg

soil)

Bs = Soil bioavailability factor (unitless)

Bachicken = PB-HAP compound biotransfer factor for chicken (day/kg FW tissue)

Baegg = PB-HAP compound biotransfer factor for eggs (day/kg FW tissue)

EPA (1998)(1) describes determination of compound specific parameters Bachicken and Baegg. The

remaining parameters are discussed in the following subsections.

6.1.1 Fraction of Plant Type i Grown on Contaminated Soil and Eaten by the Animal

(Chicken)(Fi)

The calculation of Fi for chicken is identical to that for beef cattle (Section 4.4.1).

6.1.2 Quantity of Plant Type i Eaten by the Animal (Chicken) Each Day (Qpi)

Because chickens are not grazing animals, they are assumed not to eat forage. Chickens are

assumed not to consume any silage. The daily quantity of plant feeds (kilograms of DW)
April 2004 Page K-24

consumed by chicken only should be estimated for grain feed. EPA (1998)(1) recommends the

use of the following ingestion rate (Qpi): Grain = 0.2 kg DW/day. Uncertainties associated with

this variable include the variability of actual grain ingestion rates from site to site. In addition,

the assumption of uniform contamination of plant materials consumed by chicken produces some

uncertainty.

6.1.3 Concentration of PB-HAP compound in Plant Type i Eaten by the Animal

(Chicken) (Pi)

The total PB-HAP compound concentration is the PB-HAP compound concentration in grain and

can be calculated by using Equation 16. Values for Pr can be derived by using Equation 10.

(Equation 16)

where

Pi = Concentration of PB-HAP compound in each plant type i eaten by the animal (mg PBHAP compound/kg DW)

Pr = Plant concentration due to root uptake (mg PB-HAP compound/kg DW)

6.1.4 Quantity of Soil Eaten by the Animal (Chicken) Each Day (Qs)

PB-HAP compound concentration in chickens also results from intake of soil. As discussed

earlier, chickens are assumed to consume 10 percent of their total diet as soil. EPA (1998)(1) 

recommends the following soil ingestion rate for chicken: 0.022 kg DW/day. Uncertainties

associated with this variable include the lack of current empirical data to support soil ingestion

rates for chicken, and the assumption of uniform contamination of soil ingested by chicken.

6.1.5 Average Soil Concentration Over Exposure Duration (Cs)

The calculation of Cs for chicken is the same as for beef cattle (Section 4.4.5).

6.1.6 Soil Bioavailability Factor (Bs)

The calculation of Bs for chicken is the same as for beef cattle (Section 4.4.6)

7.0 Calculation of PB-HAP Compound Concentrations in Drinking Water and Fish

PB-HAP compound concentrations in surface water are calculated for all water bodies selected

for evaluation in the risk assessment; specifically, evaluation of the drinking water and/or fish

ingestion exposure pathways. Mechanisms considered for determination of PB-HAP compound

loading of the water column are:

(1) Direct deposition, 

(2) Runoff from impervious surfaces within the watershed, 

(3) Runoff from pervious surfaces within the watershed, 

(4) Soil erosion over the total watershed, 

(5) Direct diffusion of vapor phase PB-HAP compounds into the surface water, and

(6) Internal transformation of compounds chemically or biologically.
April 2004 Page K-25

Other potential mechanisms may need consideration on a case-by-case basis (e.g., tidal

influences), however, contributions from other potential mechanisms are assumed to be

negligible in comparison with those being evaluated.

The USLE and a sediment delivery ratio are used to estimate the rate of soil erosion from the

watershed. In the ISCST3 model, surface water concentration algorithms include a sediment

mass balance, in which the amount of sediment assumed to be buried and lost from the water 

body is equal to the difference between the amount of soil introduced to the water body by

erosion and the amount of suspended solids lost in downstream flow. As a result, the

assumptions are made that sediments do not accumulate in the water body over time, and an

equilibrium is maintained between the surficial layer of sediments and the water column. The

total water column PB-HAP compound concentration is the sum of the PB-HAP compound

concentration dissolved in water and the PB-HAP compound concentration associated with

suspended solids. Partitioning between water and sediment varies with the PB-HAP compound. 

The total concentration of each PB-HAP compound is partitioned between the sediment and the

water column. The assumptions for other multimedia models may differ. 

To evaluate the PB-HAP compound loading to a water body from its associated watershed, it is

recommended that the PB-HAP compound concentration in watershed soils be calculated. As

described in Section 2, the equation for PB-HAP compound concentration in soil includes a loss

term that considers the loss of contaminants from the soil after deposition. These loss

mechanisms all lower the soil concentration associated with a specific deposition rate.

The ISCST3 model approach for modeling PB-HAP compound loading to a water body

represents a simple steady-state model to solve for a water column in equilibrium with the upper

sediment layer. This approach may be limited in addressing the dynamic exchange of

contaminants between the water body and the sediments following changes in external loadings. 

While appropriate for calculating risk under long-term average conditions, the evaluation of

complex water bodies or shorter term loading scenarios may be improved through the use of a

dynamic modeling framework [e.g., Exposure Analysis Modeling System (EXAMS)]. Although

typically more resource intensive, such analysis may offer the ability to refine modeling of

contaminant loading to a water body. Additionally, the computations may better represent the

exposure scenario being evaluated. 

For example, EXAMS allows computations to be performed for each defined segment or

compartment of a water body or stream. These compartments are considered physically

homogeneous and are connected via advective and dispersive fluxes. Compartments can be

defined as littoral, epilimnion, hypolimnion, or benthic. Such resolution also makes it possible to

assign receptor locations specific to certain portions of a water body where evaluation of

exposure is of greatest interest.

Some considerations regarding the selection and use of a dynamic modeling framework or

simulation model to evaluate water bodies may include the following:

• Will a complex surface water modeling effort provide enhanced results over the use of the

more simplistic steady-state equations;
April 2004 Page K-26

• Are the resources needed to conduct, as well as review, a more complex modeling effort

justified in comparison to the refinement to results provided;

• Has the model been used previously for regulatory purposes, and therefore, already has

available documentation to support such uses;

• Can the model conduct steady-state and dynamic analysis; and

• Does the model require calibration with field data, and if so, are there sufficient quantity and

quality of site-specific data available to support calibration. 

7.1 Total PB-HAP compound Load to the Water Body (LT)

EPA (1998)(1) recommends the use of Equation 17 to calculate the total PB-HAP compound load

to a water body (LT).

(Equation 17)

where

LT = Total PB-HAP compound load to the water body (including deposition, runoff, and

erosion) (g/yr)

LDEP

= Total (wet and dry) particle phase and vapor phase PB-HAP compound direct

deposition load to water body (g/yr)

Ldif

= Vapor phase PB-HAP compound diffusion load to water body (g/yr)

LRI = Runoff load from impervious surfaces (g/yr)

LR = Runoff load from pervious surfaces (g/yr)

LE = Soil erosion load (g/yr)

LI = Internal transfer (g/yr)

Due to the limited data and uncertainty associated with the chemical or biological internal

transfer, LI, of compounds into daughter products, EPA (1998)(1) recommends a default value for

this variable of zero. However, if a permitting authority determines that site-specific conditions

indicate calculation of internal transfer may need to be considered, EPA (1998)(1) recommends

following the methodologies described in EPA NCEA document, Methodology for Assessing

Health Risks Associated with Multiple Pathways of Exposure to Combustor Emissions (EPA

1998).(12) Calculation of each of the remaining variables (LDEP, Ldif, LRI, LR, and LE) is discussed in

the following subsections.

7.1.1 Total (Wet and Dry) Particle Phase and Vapor Phase PB-HAP compound Direct

Deposition Load to Water Body (LDEP)

EPA (1998)(1) recommends Equation 18 to calculate the load to the water body from the direct

deposition of wet and dry particles and vapors onto the surface of the water body (LDEP).

(Equation 18)
April 2004 Page K-27

where

LDEP = Total (wet and dry) particle phase and vapor phase PB-HAP compound direct

deposition load to water body (g/yr)

Q = PB-HAP compound emission rate (g/s)

Fv = Fraction of PB-HAP compound air concentration in vapor phase (unitless)

Dytwv = Unitized yearly (water body or watershed) average total (wet and dry) deposition from

vapor phase (s/m2-yr)

Dytwp = Unitized yearly (water body or watershed) average total (wet and dry) deposition from

particle phase (s/m2-yr)

AW = Water body surface area (m2)

7.1.2 Vapor Phase PB-HAP compound Diffusion Load to Water Body (Ldif)

EPA (1998)(1) recommends using Equation 19 to calculate the vapor phase PB-HAP compound

diffusion load to the water body (Ldif).

(Equation 19)

where

Ldif

= Vapor phase PB-HAP compound diffusion load to water body (g/yr)

Kv = Overall PB-HAP compound transfer rate coefficient (m/yr)

Q = PB-HAP compound emission rate (g/s)

Fv = Fraction of PB-HAP compound air concentration in vapor phase (unitless)

Cywv = Unitized yearly (water body or watershed) average air concentration from vapor phase

(μg-s/g-m3)

AW = Water body surface area (m2)

10-6 = Units conversion factor (g/μg)

H = Henry’s Law constant (atm-m3/mol)

R = Universal gas constant (atm-m3/mol-K)

Twk = Water body temperature (K)

The overall PB-HAP compound transfer rate coefficient (Kv) is calculated by using Equation 29

(see section 7.4.4). EPA (1998)(1) recommends a water body temperature (Twk) of 298 K (or

25°C).

7.1.3 Runoff Load from Impervious Surfaces (LRI)

In some watershed soils, a fraction of the total (wet and dry) deposition in the watershed will be

to impervious surfaces. This deposition may accumulate and be washed off during rain events. 

EPA (1998)(1) recommends the use of Equation 20 to calculate impervious runoff load to a water

body (LRI).
April 2004 Page K-28

(Equation 20)

where

LRI = Runoff load from impervious surfaces (g/yr)

Q = PB-HAP compound emission rate (g/s)

Fv = Fraction of PB-HAP compound air concentration in vapor phase (unitless)

Dytwv = Unitized yearly (water body or watershed) average total (wet and dry) deposition from

vapor phase (s/m2-yr)

Dytwp = Unitized yearly (water body or watershed) average total (wet and dry) deposition from

particle phase (s/m2-yr)

AI = Impervious watershed area receiving PB-HAP compound deposition (m2)

Impervious watershed area receiving PB-HAP compound deposition (AI) is the portion of the

total effective watershed area that is impervious to rainfall (such as roofs, driveways, streets, and

parking lots) and drains to the water body.

7.1.4 Runoff Load from Pervious Surfaces (LR)

EPA (1998)(1) recommends the use of Equation 21 to calculate the runoff dissolved PB-HAP

compound load to the water body from pervious soil surfaces in the watershed (LR).

(Equation 21)

where

LR = Runoff load from pervious surfaces (g/yr)

RO = Average annual surface runoff from pervious areas (cm/yr)

AL = Total watershed area receiving PB-HAP compound deposition (m2)

AI = Impervious watershed area receiving PB-HAP compound deposition (m2)

Cs = Average soil concentration over exposure duration (in watershed soils) (mg PB-HAP

compound/kg soil)

BD = Soil bulk density (g soil/cm3 soil)

2sw = Soil volumetric water content (mL water/cm3 soil)

Kds = Soil-water partition coefficient (cm3 water/g soil)

0.01 = Units conversion factor (kg-cm2/mg-m2)

The calculation of the PB-HAP compound concentration in watershed soils (Cs) are discussed in

Section 2.1. Soil bulk density (BD) is described in Section 2.5.2. Soil water content (2sw) is

described in Section 2.5.4.
April 2004 Page K-29

7.1.5 Soil Erosion Load (LE)

EPA (1998)(1) recommends the use of Equation 22 to calculate soil erosion load (LE).

(Equation 22)

where

LE = Soil erosion load (g/yr)

Xe = Unit soil loss (kg/m2-yr)

AL = Total watershed area (evaluated) receiving PB-HAP compound deposition (m2)

AI = Impervious watershed area receiving PB-HAP compound deposition (m2)

SD = Sediment delivery ratio (watershed) (unitless)

ER = Soil enrichment ratio (unitless)

Cs = Average soil concentration over exposure duration (in watershed soils) (mg PB-HAP

compound/kg soil)

BD = Soil bulk density (g soil/cm3 soil)

2sw = Soil volumetric water content (mL water/cm3 soil)

Kds = Soil-water partition coefficient (mL water/g soil)

0.001 = Units conversion factor (k-cm2/mg-m2)

Unit soil loss (Xe) is described in Section 7.2. Watershed sediment delivery ratio (SD) is

calculated as described in Section 7.3. PB-HAP compound concentration in soils (Cs) is

described in Section 2.1. Soil bulk density (BD) is described in Section 2.5.2. Soil water content

(2sw) is described in Section 2.5.4. 

7.2 Universal Soil Loss Equation - USLE

EPA (1998)(1) recommends that the universal soil loss equation (USLE), Equation 22A, be used

to calculate the unit soil loss (Xe) specific to each watershed.

(Equation 22A)

where

Xe = Unit soil loss (kg/m2-yr)

RF = USLE rainfall (or erosivity) factor (yrG1)

K = USLE erodibility factor (ton/acre)

LS = USLE length-slope factor (unitless)

C = USLE cover management factor (unitless)

PF = USLE supporting practice factor (unitless)

907.18 = Units conversion factor (kg/ton)

4047 = Units conversion factor (m2/acre)
April 2004 Page K-30

The USLE RF variable, which represents the influence of precipitation on erosion, is derived

from data on the frequency and intensity of storms. This value is typically derived on a stormby-storm basis, but average annual values have been compiled (U.S. Department of Agriculture

1982).(31) Information on determining site-specific values for variables used in calculating Xe is

provided in U.S. Department of Agriculture (U.S. Department of Agriculture 1997)(32) and EPA

guidance (EPA 1985).(22)

7.3 Sediment Delivery Ratio (SD)

EPA (1998)(1) recommends the use of Equation 23 to calculate sediment delivery ratio (SD).

(Equation 23)

where

SD = Sediment delivery ratio (watershed) (unitless)

a = Empirical intercept coefficient (unitless)

b = Empirical slope coefficient (unitless)

AL = Total watershed area (evaluated) receiving PB-HAP compound deposition (m2)

AL is the total watershed surface area evaluated that is affected by deposition and drains to the

body of water (see Chapter 2). In assigning values to the watershed surface area affected by

deposition, the following may be a consideration:

• Distance from the emission source;

• Location of the area affected by deposition fallout with respect to the point at which drinking

water is extracted or fishing occurs; and

• The watershed hydrology. 

7.4 Total Water Body PB-HAP compound Concentration (Cwtot)

EPA (1998)(1) recommends the use of Equation 24 to calculate total water body PB-HAP

compound concentration (Cwtot). The total water body concentration includes both the water

column and the bed sediment.

(Equation 24)

where

Cwtot = Total water body PB-HAP compound concentration (including water column and bed

sediment) (g PB-HAP compound/m3 water body)

LT = Total PB-HAP compound load to the water body (including deposition, runoff, and

erosion) (g/yr)

Vfx = Average volumetric flow rate through water body (m3/yr)

fwc = Fraction of total water body PB-HAP compound concentration in the water column

(unitless)

kwt = Overall total water body PB-HAP compound dissipation rate constant (yrG1)
April 2004 Page K-31

AW = Water body surface area (m2)

dwc = Depth of water column (m)

dbs = Depth of upper benthic sediment layer (m)

The total PB-HAP compound load to the water body (LT) – including deposition, runoff, and

erosion – is described in Section 7.1. The depth of the upper benthic layer (dbs), which represents

the portion of the bed that is in equilibrium with the water column, cannot be precisely specified;

however, EPA (1998)(1) recommends a default value of 0.03. Issues related to the remaining

parameters are summarized in the following subsections.

7.4.1 Fraction of Total Water Body PB-HAP compound Concentration in the Water

Column (fwc) and Benthic Sediment (fbs)

EPA (1998)(1) recommends using Equation 25A to calculate fraction of total water body PB-HAP

compound concentration in the water column (fwc), and Equation 25B to calculate total water

body contaminant concentration in benthic sediment (f

bs).

(Equation 25A)

(Equation 25B)

where

fwc = Fraction of total water body PB-HAP compound concentration in the water

column (unitless)

f

bs = Fraction of total water body PB-HAP compound concentration in benthic

sediment (unitless)

Kdsw = Suspended sediments/surface water partition coefficient (L water/kg suspended

sediment)

TSS = Total suspended solids concentration (mg/L)

1 x 10-6 = Units conversion factor (kg/mg)

dz = Total water body depth (m)

2bs = Bed sediment porosity (Lwater/Lsediment)

Kdbs = Bed sediment/sediment pore water partition coefficient (L water/kg bottom

sediment)

CBS = Bed sediment concentration (g/cm3 [equivalent to kg/L])

dwc = Depth of water column (m)

dbs = Depth of upper benthic sediment layer (m)

The partition coefficient Kdsw describes the partitioning of a contaminant between sorbing

material, such as soil, surface water, suspended solids, and bed sediments. Due to variability in

water body specific values, EPA (1998)(1) recommends the use of water body-specific measured

total suspended solids (TSS) values representative of long-term average annual values for the

water body of concern. Average annual values for TSS are generally expected to be in the range
April 2004 Page K-32

of 2 to 300 mg/L; with additional information on anticipated TSS values available in the EPA

NCEA document, Methodology for Assessing Health Risks Associated with Multiple Pathways of

Exposure to Combustor Emissions (EPA 1998).(12) If measured data are not available, or of

unacceptable quality, a calculated TSS value can be obtained for non-flowing water bodies using

Equation 25C.

(Equation )25C

where

TSS = Total suspended solids concentration (mg/L)

Xe = Unit soil loss (kg/m2-yr)

AL = Total watershed area (evaluated) receiving PB-HAP compound deposition (m2)

AI = Impervious watershed area receiving PB-HAP compound deposition (m2)

SD = Sediment delivery ratio (watershed) (unitless)

Vfx = Average volumetric flow rate through water body (value should be 0 for quiescent

lakes or ponds) (m3/yr)

Dss = Suspended solids deposition rate (a default value of 1,825 for quiescent lakes or

ponds) (m/yr)

AW = Water body surface area (m2)

1x10-3 = Units conversion factor (g/kg)

The default value of 1,825 m/yr provided for Dss is characteristic of Stoke’s settling velocity for

an intermediate (fine to medium) silt.

Also, to evaluate the appropriateness of watershed-specific values used in calculating the unit

soil loss (Xe), as described in Section 7.2, the water-body specific measured TSS value can be

compared to the calculated TSS value obtained using Equation 25C. If the measured and

calculated TSS values differ significantly, parameter values used in calculating Xe can be reevaluated. This re-evaluation of TSS and Xe

 can also be conducted if the calculated TSS value is

outside of the normal range expected for average annual measured values, as discussed above.

Bed sediment porosity (2bs) can be calculated from the bed sediment concentration by using

Equation 26 (EPA 1993b)(11):

(Equation 26)

where

2bs = Bed sediment porosity (Lwater/Lsediment)

Ds = Bed sediment density (kg/L)

CBS = Bed sediment concentration (kg/L)
April 2004 Page K-33

EPA (1998)(1) recommends the default value of 0.6 Lwater/Lsediment for bed sediment porosity (2bs). 

This assumes a bed sediment density (Ds ) of 2.65 kg/L and a bed sediment concentration (CBS) of

1.0 kg/L.

7.4.2 Overall Total Water Body PB-HAP compound Dissipation Rate Constant (kwt)

EPA (1998)(1) recommends the use of Equation 27 to calculate the overall dissipation rate of PBHAP compounds in surface water, resulting from volatilization and benthic burial.

(Equation 27)

where

kwt

= Overall total water body dissipation rate constant (yrG1)

fwc = Fraction of total water body PB-HAP compound concentration in the water column

(unitless)

kv = Water column volatilization rate constant (yrG1)

f

bs = Fraction of total water body PB-HAP compound concentration in benthic sediment

(unitless)

kb = Benthic burial rate constant (yrG1)

The variables fwc and f

bs are discussed in Section 7.4.1, and Equations 25A and 25B.

7.4.3 Water Column Volatilization Rate Constant (kv)

EPA (1998)(1) recommends using Equation 28 to calculate water column volatilization rate

constant.

(Equation 28)

where

kv = Water column volatilization rate constant (yrG1)

Kv = Overall PB-HAP compound transfer rate coefficient (m/yr)

dz = Total water body depth (m)

Kdsw = Suspended sediments/surface water partition coefficient (L water/kg suspended

sediments)

TSS = Total suspended solids concentration (mg/L)

1 x 10-6 = Units conversion factor (kg/mg)

Total water body depth (dz), suspended sediment and surface water partition coefficient (Kdsw),

and total suspended solids concentration (TSS), are described in Section 7.4.1. The overall

transfer rate coefficient (Kv) is described in Section 7.4.4.
April 2004 Page K-34

7.4.4 Overall PB-HAP compound Transfer Rate Coefficient (Kv)

Volatile organic chemicals can move between the water column and the overlying air. The

overall transfer rate Kv, or conductivity, is determined by a two-layer resistance model that

assumes that two “stagnant films” are bounded on either side by well-mixed compartments. 

Concentration differences serve as the driving force for the water layer diffusion. Pressure

differences drive the diffusion for the air layer. From balance considerations, the same mass

must pass through both films; the two resistances thereby combine in series, so that the

conductivity is the reciprocal of the total resistance.

EPA (1998)(1) recommends the use of Equation 29 to calculate the overall transfer rate

coefficient (Kv).

(Equation 29)

where

Kv = Overall PB-HAP compound transfer rate coefficient (m/yr)

KL = Liquid phase transfer coefficient (m/yr)

KG = Gas phase transfer coefficient (m/yr)

H = Henry’s Law constant (atm-m3/mol)

R = Universal gas constant (atm-m3/mol-K)

Twk = Water body temperature (K)

2 = Temperature correction factor (unitless)

The value of the conductivity Kv depends on the intensity of turbulence in the water body and the

overlying atmosphere. As Henry’s Law constant increases, the conductivity tends to be

increasingly influenced by the intensity of turbulence in water. Conversely, as Henry’s Law

constant decreases, the value of the conductivity tends to be increasingly influenced by the

intensity of atmospheric turbulence. 

The liquid and gas phase transfer coefficients, KL and KG, respectively, vary with the type of

water body. The liquid phase transfer coefficient (KL) is calculated by using Equations 30A and

30B (described in Section 7.4.5). The gas phase transfer coefficient (KG) is calculated by using

Equations 31A and 31B (described in Section 7.4.6).

Henry’s Law constants generally increase with increasing vapor pressure of a PB-HAP

compound and generally decrease with increasing solubility of a PB-HAP compound. Henry’s

Law constants are compound-specific and are presented in Appendix D. The universal ideal gas

constant, R, is 8.205 × 10-5 atm-m3/mol-K, at 20°C. The temperature correction factor (2), which

is equal to 1.026, is used to adjust for the actual water temperature. Volatilization is assumed to

occur much less readily in lakes and reservoirs than in moving water bodies.
April 2004 Page K-35

7.4.5 Liquid Phase Transfer Coefficient (KL)

EPA (1998)(1) recommends using Equations 30A and 30B to calculate liquid phase transfer

coefficient. (KL).

(Equation 30A)

(Equation 30B)

where

KL = Liquid phase transfer coefficient (m/yr)

Dw = Diffusivity of PB-HAP compound in water (cm2/s)

u = Current velocity (m/s)

1 × 10-4 = Units conversion factor (m2/cm2)

dz = Total water body depth (m)

Cd = Drag coefficient (unitless)

W = Average annual wind speed (m/s)

Da = Density of air (g/cm3)

Dw = Density of water (g/cm3)

k = von Karman’s constant (unitless)

8z = Dimensionless viscous sublayer thickness (unitless)

:w = Viscosity of water corresponding to water temperature (g/cm-s)

3.1536 x 107

=

Units conversion factor (s/yr)

For a flowing stream or river, the transfer coefficients are controlled by flow-induced turbulence. 

For these systems, the liquid phase transfer coefficient is calculated by using Equation 30A. For

a stagnant system (quiescent lake or pond), the transfer coefficient is controlled by wind-induced

turbulence, and the liquid phase transfer coefficient can be calculated by using Equation 30B. 

The total water body depth (dz) for liquid phase transfer coefficients is discussed in Section 7.4.1. 

EPA (1998)(1) recommends the use of the following default values:

• A diffusivity of chemical in water ranging (Dw) from 1.0 × 10G5 to 8.5 × 10-2 cm2/s;

• A dimensionless viscous sublayer thickness (8z) of 4;

• A von Karman’s constant (k) of 0.4;

• A drag coefficient (Cd) of 0.0011;

• An air density (Da) of 0.0012 g/cm3 at standard conditions (temperature = 20°C or 293 K,

pressure = 1 atm or 760 millimeters of mercury);

• A water density of(Dw) of 1 g/cm3; and

• A water viscosity(:w) of a 0.0169 g/cm-s corresponding to water temperature.
April 2004 Page K-36

7.4.6 Gas Phase Transfer Coefficient (KG)

EPA (1998)(1) recommends using Equations 31A and 31B to calculate gas phase transfer

coefficient (KG).

For flowing streams or rivers:

(Equation 31A)

For quiescent lakes or ponds:

(Equation 31B)

where

KG = Gas phase transfer coefficient (m/yr)

Cd = Drag coefficient (unitless)

W = Average annual wind speed (m/s)

k = von Karman’s constant (unitless)

8z = Dimensionless viscous sublayer thickness (unitless)

:a = Viscosity of air corresponding to air temperature (g/cm-s)

Da = Density of air corresponding to water temperature (g/cm3)

Da = Diffusivity of PB-HAP compound in air (cm2/s)

3.1536 x 107 = Units conversion factor (s/yr)

EPA (1998)(1) recommends 1.81 x 10-4 g/cm-s for the viscosity of air corresponding to air

temperature.

7.4.7 Benthic Burial Rate Constant (kb)

EPA (1998)(1) recommends using Equation 32 to calculate benthic burial rate (kb).

(Equation 32)

where

kb = Benthic burial rate constant (yrG1)

Xe = Unit soil loss (kg/m2-yr)

AL = Total watershed area (evaluated) receiving deposition (m2)

SD = Sediment delivery ratio (watershed) (unitless)

Vfx = Average volumetric flow rate through water body (m3/yr)

TSS = Total suspended solids concentration (mg/L)

AW = Water body surface area (m2)
April 2004 Page K-37

CBS = Bed sediment concentration (g/cm3)

dbs = Depth of upper benthic sediment layer (m)

1 x 10G6

=

Units conversion factor (kg/mg)

1 x 103 = Units conversion factor (g/kg)

The benthic burial rate constant (kb), can also be expressed in terms of the rate of burial (Wb)

(Equation 33):

(Equation 33)

where

Wb = Rate of burial (m/yr)

kb = Benthic burial rate constant (yrG1)

dbs

= Depth of upper benthic sediment layer (m)

EPA (1998)(1) recommends the following default value of 1.0 kg/L for bed sediment

concentration (CBS). 

Section 7.2 discusses the unit soil loss (Xe). Section 7.3 discusses sediment delivery ratio (SD)

and watershed area evaluated receiving PB-HAP compound deposition (AL). Section 7.4

discusses the depth of the upper benthic sediment layer (dbs). Average volumetric flow rate

through the water body (Vfx) and water body surface area (Aw) are discussed further in EPA

(1998).

(1) Section 7.4.1 discusses total suspended solids concentration (TSS).

The calculated value for kb is expected to range from 0 to 1.0; with low kb values expected for

water bodies characteristic of no or limited sedimentation (rivers and fast flowing streams), and

kb values closer to 1.0 expected for water bodies characteristic of higher sedimentation (lakes). 

This range of values is based on the relation between the benthic burial rate and rate of burial

expressed in Equation 33; with the depth of upper benthic sediment layer held constant. For kb

values calculated as a negative (water bodies with high average annual volumetric flow rates in

comparison to watershed area evaluated), EPA (1998)(1) recommends assigning a kb value of 0

for use in calculating the total water body PB-HAP compound concentration (Cwtot) in

Equation 34 (see next section). If the calculated kb value exceeds 1.0, re-evaluation of the

parameter values used in calculating Xe is recommended to be conducted.
April 2004 Page K-38

7.4.8 Total PB-HAP compound Concentration in Water Column (Cwctot)

EPA (1998)(1) recommends using Equation 34 to calculate total PB-HAP compound

concentration in water column (Cwctot).

(Equation 34)

where

Cwctot = Total PB-HAP compound concentration in water column (mg PB-HAP compound/L

water column)

fwc = Fraction of total water body PB-HAP compound concentration in the water column

(unitless)

Cwtot = Total water body PB-HAP compound concentration, including water column and bed

sediment (mg PB-HAP compound/L water body)

dwc = Depth of water column (m)

dbs = Depth of upper benthic sediment layer (m)

Total water body PB-HAP compound concentration – including water column and bed sediment

(Cwtot) and fraction of total water body PB-HAP compound concentration in the water column

(fwc) – can be calculated by using Equation 34 and Equation 35 (see next section). Depth of

upper benthic sediment layer (dbs) is discussed in Section 7.4.1.

7.4.9 Dissolved Phase Water Concentration (Cdw)

EPA (1998)(1) recommends the use of Equation 35 to calculate the concentration of PB-HAP

compound dissolved in the water column (Cdw).

(Equation 35)

where

Cdw = Dissolved phase water concentration (mg PB-HAP compound/L water)

Cwctot = Total PB-HAP compound concentration in water column (mg PB-HAP

compound/L water column)

Kdsw = Suspended sediments/surface water partition coefficient (L water/kg suspended

sediment)

TSS = Total suspended solids concentration (mg/L)

1 x 10-6 = Units conversion factor (kg/mg)

The total PB-HAP compound concentration in water column (Cwctot) is calculated by using the

Equation 34. Section 7.4.1 discusses the surface water partition coefficient (Kdsw) and total

suspended solids concentration (TSS).
April 2004 Page K-39

7.4.10 PB-HAP compound Concentration Sorbed to Bed Sediment (Csb)

EPA (1998)(1) recommends the use of Equation 36 to calculate PB-HAP compound

concentration sorbed to bed sediment (Csb).

(Equation 36)

where

Csb = PB-HAP compound concentration sorbed to bed sediment (mg PB-HAP

compound/kg sediment)

f

bs = Fraction of total water body PB-HAP compound concentration in benthic sediment

(unitless)

Cwtot

= Total water body PB-HAP compound concentration, including water column and bed

sediment (mg PB-HAP compound/L water body)

Kdbs = Bed sediment/sediment pore water partition coefficient (L PB-HAP compound/kg

water body)

2bs = Bed sediment porosity (Lpore water/Lsediment)

CBS = Bed sediment concentration (g/cm3)

dwc = Depth of water column (m)

dbs = Depth of upper benthic sediment layer (m)

Bed sediment porosity (2bs) and bed sediment concentration (CBS) are discussed in Section 7.4.1. 

Depth of water column (dwc) and depth of upper benthic layer (dbs) are discussed in Section 7.4.

7.5 Concentration of PB-HAP compound in Fish (Cfish)

The PB-HAP compound concentration in fish is calculated using either a PB-HAP compoundspecific bioconcentration factor (BCF), a PB-HAP compound-specific bioaccumulation factor

(BAF), or a PB-HAP compound-specific biota-sediment accumulation factor (BSAF). For

compounds with a log Kow less than 4.0, BCFs are used. Compounds with a log Kow greater than

4.0 (except for extremely hydrophobic compounds such as polycyclic organic matter and PCBs), 

are assumed to have a high tendency to bioaccumulate, therefore, BAFs are used. While

extremely hydrophobic PB-HAP compounds are also assumed to have a high tendency to

bioaccumulate, they are expected to be sorbed to the bed sediments more than associated with the

water phase. Therefore, for polycyclic organic matter and PCBs, EPA (1998)(1) recommends

using BSAFs to calculate concentrations in fish.

BCF and BAF values are generally based on dissolved water concentrations. Therefore, when

BCF or BAF values are used, the PB-HAP compound concentration in fish is calculated using

dissolved water concentrations. BSAF values are based on benthic sediment concentrations. 

Therefore, when BSAF values are used, PB-HAP compound concentration in fish is calculated

using benthic sediment concentrations. The equations used to calculate fish concentrations are

described in the subsequent subsections.
April 2004 Page K-40

7.5.1 Fish Concentration (Cfish) from Bioconcentration Factors Using Dissolved Phase

Water Concentration

EPA (1998)(1) recommends the use of Equation 37 to calculate fish concentration from BCFs

using dissolved phase water concentration.

(Equation 37)

where

Cfish = Concentration of PB-HAP compound in fish (mg PB-HAP compound/kg FW

tissue)

Cdw = Dissolved phase water concentration (mg PB-HAP compound/L)

BCFfish = Bioconcentration factor for PB-HAP compound in fish (L/kg)

The dissolved phase water concentration (Cdw) is calculated by using Equation 35.

7.5.2 Fish Concentration (Cfish) from Bioaccumulation Factors Using Dissolved Phase

Water Concentration

EPA (1998)(1) recommends the use of Equation 38 to calculate fish concentration from BAFs

using dissolved phase water concentration.

(Equation 38)

where

Cfish = Concentration of PB-HAP compound in fish (mg PB-HAP compound/kg FW tissue)

Cdw = Dissolved phase water concentration (mg PB-HAP compound/L)

BAFfish = Bioaccumulation factor for PB-HAP compound in fish (L/kg FW tissue)

The dissolved phase water concentration (Cdw) is calculated by using Equation 35.

7.5.3 Fish Concentration (Cfish) from Biota-To-Sediment Accumulation Factors Using PBHAP compound Sorbed to Bed Sediment

EPA (1998)(1) recommends the use of Equation 39 to calculate fish concentration from BSAFs

using PB-HAP compound sorbed to bed sediment for very hydrophobic compounds (polycyclic

organic matter and PCBs).

(Equation 39)

where

Cfish = Concentration of PB-HAP compound in fish (mg PB-HAP compound/kg FW tissue)
April 2004 Page K-41

Csb = Concentration of PB-HAP compound sorbed to bed sediment (mg PB-HAP

compound/kg bed sediment)

f

lipid = Fish lipid content (unitless)

BSAF = Biota-to-sediment accumulation factor (unitless)

OCsed = Fraction of organic carbon in bottom sediment (unitless)

The concentration of PB-HAP compound sorbed to bed sediment (Csb) is calculated by using

Equation 36. EPA recommended default values for the fish lipid content (f

lipid) and for the

fraction of organic carbon in bottom sediment (OCsed) are given in EPA (1998).

(1)

Values for the fraction of organic carbon in bottom sediment recommended by EPA (1993b)(11) 

range from 0.03 to 0.05 (Ocsed). These values are based on an assumption of a surface soil OC

content of 0.01. This document states that the organic carbon content in bottom sediments is

higher than the organic carbon content in soils because (1) erosion favors lighter-textured soils

with higher organic carbon contents, and (2) bottom sediments are partially comprised of detritus

materials. 

The fish lipid content (f

lipid) value is site-specific and dependent on the type of fish. As stated in

EPA (1998)(1) , a default range of 0.03 to 0.07 is recommended specific to warm or cold water

fish species. EPA (2000)(33) provides information supporting a value of 0.03 (3 percent lipid

content of the edible portion). EPA (1993a)(34) recommended a default value of 0.04 for OCsed, 

which is the midpoint of the specified range. EPA (1993b; 1993a)(11)(34) recommended the use of

0.07, which was originally cited in Cook et al. (1991).(35)

8.0 Concentrations of Dioxins in Breast Milk

EPA (1998)(1) recommends the use of Equation 40 to estimate the concentrations of dioxins in

breast milk.

(Equation 40)

where

Cmilkfat = Concentration of dioxin in milk fat of breast milk for a specific exposure scenario (pg

dioxin/kg milk fat)

m = Average maternal intake of dioxin for each adult exposure scenario (mg dioxin/kg

BW-day)

1×109 = Units conversion factor (pg/mg)

h = Half-life of dioxin in adults (days)

f

1 = Fraction of ingested dioxin that is stored in fat (unitless)

f

2 = Fraction of mother’s weight that is fat (unitless)

The values of m, h, f

1

, and f

2

 are site-specific and dependent on the specific species of dioxin

present. EPA (1998)(1) recommends a default value of 2,555 days for h, a default value of 0.9 for 

f

1

, and a default value of 0.3 for f

2

 . Additional references for the derivation of this equation and

these default values are given in EPA (1998).

(1)
April 2004 Page K-42

1. U.S. Environmental Protection Agency. 1998. Human Health Risk Assessment Protocol for

Hazardous Waste Combustion Facilities, Volume 1, Peer Review Draft. Office of Solid

Waste and Emergency Response, July 1998, available at:

http://www.epa.gov/epaoswer/hazwaste/combust/risk.htm

2. Bohn H., B.L. McNeal, and G.A. O’Connor. 1985. Soil Chemistry. John Wiley and Sons,

Inc. New York. Second Edition.

3. Sparks, D.L. 1989. Kinetics of Soil Chemical Processes. Academic Press, Inc. San Diego,

California.

4. U.S. Environmental Protection Agency. 1990. Interim Final Methodology for Assessing

Health Risks Associated with Indirect Exposure to Combustor Emissions. Environmental

Criteria and Assessment Office. ORD. EPA-600-90-003. January.

5. Valentine, R.L. 1986. “Nonbiological Transformation.” Vadose Zone Modeling of Organic

Pollutants. S.C. Hern and S.M. Melacon, Editors. Lewis Publishers, Inc. Chelsea,

Michigan.

6. U.S. Environmental Protection Agency. 1986. Superfund Public Health Evaluation Manual. 

Office of Emergency and Remedial Response, Washington, D.C. EPA/540/1-86/060.

7. Lyman, W.J., W.F. Reehl, and D.H. Rosenblatt. 1982. Handbook of Chemical Property

Estimation Methods. McGraw-Hill Book Company. New York, New York.

8. U.S. Environmental Protection Agency. 1994a. Draft Guidance for Performing Screening

Level Risk Analyses at Combustion Facilities Burning Hazardous Wastes. Attachment C,

Draft Exposure Assessment Guidance for RCRA Hazardous Waste Combustion Facilities. 

April 15.

9. Jury, W.A., and R.L. Valentine. 1986. “Transport Mechanisms and Loss Pathways for

Chemicals in Soils.” Vadose Zone Modeling of Organic Pollutants. S.C. Hern and S.M.

Melancorn, Editors. Lewis Publishers, Inc. Chelsea, Michigan.

10. Valentine, R.L., and Schnoor. 1986. “Biotransformation.” Vadose Zone Modeling of Organic

Pollutants. S.C. Hern and S.M. Melancon, Editors. Lewis Publishers, Inc. Chelsea,

Michigan.

Uncertainties associated with this equation include:

• The most significant uncertainties are associated with the variable m. Because m is

calculated as the sum of numerous potential intakes, estimates of m incorporate uncertainties

associated with each exposure pathway. Therefore, m may be under- or over-estimated.

• This equation assumes that the concentration of dioxin in breast milk fat is the same as in

maternal fat. To the extent that this is not the case, uncertainty is introduced.

References
April 2004 Page K-43

11. U.S. Environmental Protection Agency. 1993b. Review Draft Addendum to the Methodology

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Associated with Multiple Pathways of Exposure to Combustor Emissions (MPE). Update to

EPA/600/6-90/003. Office of Research and Development, National Center for

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