2 Printed on paper containing at least 30 percent postconsumer recovered fiber. 

United States Office of Air Quality EPA-452/K-00-002 

Environmental Protection Planning and Standards August 2000 

Agency Research Triangle Park, NC 27711 http://www.epa.gov/air 

1EPA 
Photos (pages 10, 11, 13, 14, 15 and 18) by S.C. Delaney/EPA 

Photos (pages 17 and 21) Copyright © 1997 PhotoDisc, Inc. 

Photo (page 27) courtesy of State of Colorado 

Department of Public Health and Environment 
Taking Toxics Out of the Air 

Progress in Setting 

“Maximum Achievable Control Technology” 

Standards Under the Clean Air Act 

Contents 

Introduction .............................................................................................................1 

What Are Toxic Air Pollutants? ...........................................................................2 

Where Do Air Toxics Come From? ....................................................................3 

Where Do Air Toxics Go? .....................................................................................3 

How Are People Exposed to Air Toxics? .........................................................4 

Health Effects ..........................................................................................................5 

How Do Air Toxics Affect the Environment?..................................................5 

What Has EPA Done to Reduce Air Toxics? ...................................................5 

What Progress Has Been Made in Reducing Toxic Air Pollution? ..........6 

Looking Ahead ........................................................................................................7 

For Further Information........................................................................................8 

Summaries of EPA’s Final Air Toxics MACT Rules ........................................9 

Summaries of Related Solid Waste Incineration Rules ...........................31 
Air toxics are those air pollutants that are 

known or suspected to cause cancer or other 

serious health problems. Each year, millions 

of tons of air toxics are released into the air, 

mostly from manmade sources. This document 

describes what air toxics are, where they come from, 

and how they can impact people and the environimpact depends on many factors, including the quantity of air pollution to which people are exposed, the 

duration of the exposures, and the potency of the pollutants. The effects of air pollutants can be minor and 

reversible (such as eye irritation) or debilitating 

(such as aggravation of asthma) and even fatal (such 

as cancer). 

ment. It also describes the 

steps being taken by the 

U.S. Environmental 

Protection Agency to 

reduce emissions of air 

toxics from major industrial sources such as 

chemical manufacturing 

plants, petroleum refineries, and steel manufacturing plants. 

INTRODUCTION 

The air we breathe can be 

contaminated with polluThe technology- and performance-based 

standards issued by EPA over the past 

10 years have proven extremely 

successful. Once fully implemented, these 

standards will cut emissions of toxic air 

pollutants by nearly 1.5 million tons per 

year–almost 15 times greater reductions 

than EPA was able to achieve in 20 years 

prior to 1990. 

Since 1970, the Clean Air 

Act has provided the primary framework for protecting people and the 

environment from the 

harmful effects of air 

pollution. A key component of the Clean Air Act is 

a requirement that the U.S. 

Environmental Protection 

Agency (EPA) significantly 

reduce daily, so-called 

“routine” emissions of the 

tants from factories, vehicles, power plants, and many health problems such as cancer or birth defects. The other sources. These pollutants have long been a major Clean Air Act refers to these pollutants as “hazardous concern because of the harmful effects they sometimes air pollutants,” but they are also commonly known as have on people’s health and the environment. Their toxic air pollutants or, simply, air toxics. 

most potent air pollutants: 

those that are known or suspected to cause serious 

SOURCES OF AIR TOXICS 

sources. 

and manmade 

air from both natural 

are released into the 

tons of toxic pollutants 

Each year

F

A

Mobile Sources 

Stationary Sources 

Routine Emissions From 

, millions of 

o

ccidental Releases 

rest Fires 

1 
Prior to 1990, the Clean Air Act required EPA to set 

standards for each toxic air pollutant individually, 

based on its particular health risks. This approach 

proved difficult and minimally effective at reducing 

emissions. As a result, when amending the Clean Air 

Act in 1990, Congress directed EPA to use a “technology-based” and performance-based approach to significantly reduce emissions of air toxics from major 

sources of air pollution, followed by a risk-based 

approach to address any remaining, or residual, risks. 

Under the “technology-based” approach, EPA develops 

standards for controlling the “routine” emissions of air 

toxics from each major type of facility within an industry group (or “source category”). These standards— 

known as “maximum achievable control technology 

(MACT) standards”—are based on emissions levels 

that are already being achieved by the better-controlled 

and lower-emitting sources in an industry. This 

approach assures citizens nationwide that each major 

source of toxic air pollution will be required to employ 

effective measures to limit its emissions. Also, this 

approach provides a level economic playing field by 

ensuring that facilities that employ cleaner processes 

and good emission controls are not disadvantaged 

relative to competitors with poorer controls. 

In setting MACT standards, EPA does not generally 

prescribe a specific control technology. Instead, whenever feasible, the Agency sets a performance level 

based on technology or other practices already used 

by the industry. Facilities are free to achieve these 

performance levels in whatever way is most costeffective for them. The MACT standards issued by 

EPA over the past 10 years have proven extremely 

successful. Once fully implemented, these standards 

will cut emissions of toxic air pollutants by nearly 

1.5 million tons per year. 

Eight years after each MACT standard is issued, EPA 

must assess the remaining health risks from source 

categories. If necessary, EPA may implement additional 

standards that address any significant remaining risk. 

WHAT ARE TOXIC AIR 

POLLUTANTS? 

Toxic (also called hazardous) air pollutants are those 

pollutants that are known or suspected to cause cancer 

or other serious health effects, such as reproductive 

effects or birth defects, or to cause adverse environmental effects. The degree to which a toxic air pollutant 

affects a person’s health depends on many factors, 

including the quantity of pollutant the person is 

exposed to, the duration and frequency of exposures, 

the toxicity of the chemical, and the person’s state of 

health and susceptibility. 

The 1990 Clean Air Act Amendments list 188 toxic air 

pollutants that EPA is required to control.1 Examples of 

toxic air pollutants include benzene, which is found in 

1 The list originally included 189 chemicals. Based on new scientific information, EPA removed caprolactam from the list in 1996; 

thus, the current list includes 188 pollutants. 

MOBILE SOURCES AND ACCIDENTAL RELEASES 

While this document focuses on EPA’s efforts to reduce routine emissions from stationary sources, 

EPA also is working to reduce toxic emissions from: 

• Mobile sources, such as cars and trucks. For example, EPA and state governments 

(e.g., California) have reduced emissions of benzene, toluene, and other toxic pollutants from 

mobile sources by requiring the use of reformulated gasoline and placing limits on tailpipe 

emissions. For more information, contact EPA’s Office of Transportation and Air Quality at 

www.epa.gov/OMSWWW/toxics.htm or call (202) 564-1682. 

• Accidental releases, including leaks and spills. For example, EPA has established regulations 

under the Clean Air Act requiring certain facilities to implement risk management programs 

that will help prevent accidental releases of toxic chemicals. For more information, contact 

EPA’s Office of Chemical Emergency Preparedness and Prevention at www.epa.gov/swercepp 

or call (800) 424-9346. 

2 
gasoline; perchloroethylene, which is emitted from 

some dry cleaning facilities; and methylene chloride, 

which is used as a solvent and paint stripper by a number of industries. Examples of other listed air toxics 

include dioxin, asbestos, toluene, and metals such as 

cadmium, mercury, chromium, and lead compounds. 

WHERE DO AIR TOXICS 

COME FROM? 

Scientists estimate that millions of tons of toxic pollutants are released into the air each year. Most air 

toxics originate from manmade sources, including both 

mobile sources (e.g., cars, buses, trucks) and stationary 

sources (e.g., factories, refineries, power plants). 

However, some are released in major amounts from 

natural sources such as forest fires. This document 

focuses on EPA’s efforts, as of August 2000, to reduce 

routine (as opposed to accidental) emissions of toxic air 

pollutants from stationary sources. Routine emissions 

from stationary sources constitute almost one-half of 

all manmade air toxics emissions. 

There are two types of stationary sources that generate 

routine emissions of air toxics: 

•	 “Major” sources are defined as sources that emit 

10 tons per year of any of the listed toxic air pollutants, or 25 tons per year of a mixture of air toxics. 

Examples include chemical plants, steel mills, oil 

refineries, and hazardous waste incinerators. These 

sources may release air toxics from equipment leaks, 

when materials are transferred from one location 

to another, or during discharge through emissions 

stacks or vents. One key public health concern 

regarding major sources is the health effects on 

populations located downwind from them. 

•	 “Area” sources consist of smaller sources, each 

releasing smaller amounts of toxic pollutants into 

the air. Area sources are defined as sources that 

emit less than 10 tons per year of a single air toxic, 

or less than 25 tons per year of a mixture of air 

toxics. Examples include neighborhood dry cleaners 

and gas stations. Though emissions from individual 

area sources are often relatively small, collectively 

their emissions can be of concern—particularly 

where large numbers of sources are located in 

heavily populated areas. 

National Toxics 

account for about 26 percent 

of air toxics emissions, smaller area sources and other 

sources (such as forest fires) 

for 24 percent, and mobile 

sources for 50 percent. 

Accidental releases, which 

also contribute air toxics to the 

Based on 1996 

Inventory data, major sources 

atmosphere, are not included in 

these estimates. 

Mobile 

Sources 

50% Major 

Sources 

26% 

Area and 

Other Sources 

24% 

EPA’s published list of “source categories” now contains 175 categories of industrial and commercial 

sources that emit one or more toxic air pollutants. For 

each of these source categories, EPA indicated whether 

the sources are considered to be “major” sources or 

“area” sources. The 1990 Clean Air Act Amendments 

direct EPA to set standards requiring all major sources 

of air toxics (and some area sources that are of particular concern) to significantly reduce their air toxics 

emissions. 

WHERE DO AIR TOXICS GO? 

Once released, toxic pollutants can be carried by the 

wind, away from their sources, to other locations. 

Factors such as weather, the terrain (i.e., mountains, 

plains, valleys), and the chemical and physical properties of a pollutant determine how far it is transported, 

its concentration at various distances from the source, 

what kind of physical and chemical changes it undergoes, and whether it will degrade, remain airborne, or 

deposit to land or water. 

Some pollutants remain airborne and contribute to 

air pollution problems far from the pollution source. 

Other pollutants released into the air can be deposited 

to land and water bodies through precipitation, or 

by settling directly out of the air onto land or water. 

Eventually, a large portion of those pollutants 

deposited near water bodies or small tributaries will 

reach the water bodies via stormwater runoff or 

inflow from the tributary streams. 

Some toxic air pollutants are of particular concern 

because they degrade very slowly or not at all, as in 

the case of metals such as mercury or lead. These 

persistent air toxics (as they are called) can remain in 

the environment for a long time (or forever, in the case 

of metals) and can be transported great distances. 

3 
Wet 

Deposition oxic Pollutants 

Evaporation of 

Deposited Pollutants 

Dry 

Deposition 

Toxic air pollutants can be deposited to land and water bodies through precipitation (wet deposition) or by settling directly out of the 

air (dry deposition). Repeated cycles of transport, deposition, and evaporation can move toxic air pollutants very long distances. 

Often, persistent air toxics reach the ground, evaporate 

back into the atmosphere, and are then transported 

further until they are deposited on the ground again. 

Repeated cycles of transport, deposition, and 

evaporation can move toxic air pollutants very long 

distances. For example, toxic pollutants such as 

toxaphene, a pesticide used primarily in the cotton belt, 

have been found in the Antarctic, thousands of miles 

from their likely emissions sources. 

HOW ARE PEOPLE EXPOSED TO 

AIR TOXICS? 

People are exposed to toxic air pollutants in many 

ways that can pose health risks, such as by: 

• Breathing contaminated air. 

•	 Eating contaminated food products, such as fish 

from contaminated waters; meat, milk, or eggs 

from animals that fed on contaminated plants; and 

fruits and vegetables grown in contaminated soil 

on which air toxics have been deposited. 

• Drinking water contaminated by toxic air pollutants. 

•	 Eating contaminated soil. Young children are 

especially vulnerable because they may ingest 

contaminated soil from their hands or from objects 

they place in their mouths. 

•	 Touching (skin contact) contaminated soil, dust, 

or water (for example, during recreational use of 

contaminated water bodies). 

Once toxic air pollutants enter the body, some persistent toxic air pollutants accumulate in body tissues. 

Also, through a phenomenon called biomagnification, predators typically accumulate even greater 

pollutant concentrations than their contaminated 

4 
prey. As a result, people and other animals at the 

“top” of the food chain who eat contaminated fish or 

meat are exposed to concentrations that are much 

higher than the concentrations in the water, air, or soil. 

Fish consumption advisories have been issued for 

thousands of water bodies nationwide, including over 

52,000 lakes and over 238,000 miles of rivers. As of 

December 1999, 40 states have consumption advisories 

about mercury-contaminated fish for specific water 

bodies. Eleven of those states have issued state-wide 

advisories for freshwater lakes and rivers. Many of 

these water bodies were once thought to be relatively 

pristine. However, EPA is now finding that deposition 

from the air may be a major source of the pollution in 

these water bodies. 

HEALTH EFFECTS 

People who are exposed to toxic air pollutants at sufficient concentrations and for sufficient durations may 

increase their chances of getting cancer or experiencing 

other serious health effects. Depending on which air 

toxics an individual is exposed to, these health effects 

can include damage to the immune system, as well as 

neurological, reproductive (e.g., reduced fertility), 

developmental, and respiratory problems. A growing 

body of evidence indicates that some air toxics (e.g., 

DDT, dioxins, and mercury) may disturb hormonal (or 

endocrine) systems. In some cases this happens by 

pollutants either mimicking or blocking the action of 

natural hormones. Health effects associated with 

endocrine disruption include reduced male fertility, 

birth defects, and breast cancer. 

HOW DO AIR TOXICS AFFECT 

THE ENVIRONMENT? 

Toxic pollutants in the air, or deposited on soils or 

surface waters, can have a number of environmental 

impacts. Like humans, animals can experience health 

problems if they are exposed to sufficient concentrations of air toxics over time. Numerous studies conclude that deposited air toxics are contributing to birth 

defects, reproductive failure, and disease in animals. 

Persistent toxic air pollutants are of particular concern 

in aquatic ecosystems because the pollutants accumulate in sediments and may biomagnify in tissues of 

animals at the top of the food chain to concentrations 

many times higher than in the water or air. 

Toxic pollutants that mimic hormones also pose a 

threat to the environment. In some wildlife (e.g., 

birds, shellfish, fish, and mammals), exposures to 

pollutants such as DDT, dioxins, and mercury have 

been associated with decreased fertility, decreased 

hatching success, damaged reproductive organs, 

and altered immune systems. 

WHAT HAS EPA DONE TO 

REDUCE AIR TOXICS? 

The Pre-1990 “Risk-Only” Approach 

Prior to 1990, the Clean Air Act directed EPA to 

regulate toxic air pollutants based on the risks each 

pollutant posed to human health. Specifically, the 

Act directed EPA to: 

•	 Identify all pollutants that caused “serious and 

irreversible illness or death.” 

•	 Develop standards to reduce emissions of these 

pollutants to levels that provided an “ample margin 

of safety” for the public. 

While attempting to control air toxics during the 

1970s and 1980s, EPA became involved in many legal, 

scientific, and policy debates over which pollutants to 

regulate and how stringently to regulate them. 

Debates focused on risk assessment methods and 

assumptions, the amount of health risk data needed 

to justify regulation, analyses of the costs to industry 

and benefits to human health and the environment, 

and decisions about “how safe is safe.” 

During this time, EPA was still developing methods to 

assess risk. These methods were essential tools that 

would be needed to establish the scientific basis for 

making risk-based decisions about air toxics. While 

EPA and the scientific community gained valuable 

knowledge about risk assessment methods through 

this work, the chemical-by-chemical regulatory 

approach—an approach based solely on risk—proved 

difficult. In fact, in 20 years, EPA regulated only seven 

pollutants (asbestos, benzene, beryllium, inorganic 

arsenic, mercury, radionuclides, and vinyl chloride). 

Collectively, these standards cut annual air toxics 

emissions by an estimated 125,000 tons. 

5 
MAXIMUM ACHIEVABLE CONTROL TECHNOLOGY—MACT 

EPA’s MACT standards are based on the emissions levels already achieved by the best-performing 

similar facilities. This straightforward, performance-based approach yields standards that are both 

reasonable and effective in reducing toxic emissions. This approach also provides a level economic playing field by ensuring that facilities with good controls are not disadvantaged relative to 

competitors with poorer controls. 

When developing a MACT standard for a particular source category, EPA looks at the level of 

emissions currently being achieved by the best-performing similar sources through clean processes, 

control devices, work practices, or other methods. These emissions levels set a baseline (often 

referred to as the “MACT floor”) for the new standard. At a minimum, a MACT standard must achieve, 

throughout the industry, a level of emissions control that is at least equivalent to the MACT floor. 

EPA can establish a more stringent standard when this makes economic, environmental, and 

public health sense. 

The MA

provide flexibility for industry to determine the most effective way to comply with the standard. 

reduction in emissions or a concentration limit that regulated sources must achieve). Emissions 

CT floor is established differently for existing sources and new sources: 

• For existing sources, the MACT floor must equal the average emissions limitations currently 

achieved by the best-performing 12 percent of sources in that source category, if there are 30 or 

more existing sources. If there are fewer than 30 existing sources, then the MACT floor must equal 

the average emissions limitation achieved by the best-performing five sources in the category. 

• For new sources, the MACT floor must equal the level of emissions control currently achieved 

by the best-controlled similar source. 

limits 

Wherever feasible, EPA writes the final MACT standard as an emissions limit (i.e., as a percent 

The 1990 Clean Air Act Amendments: 


A “Technology First, Then Risk” Approach


Realizing the limitations of a chemical-by-chemical 

decision framework based solely on risk, and acknowledging the gaps in scientific and analytical information, 

Congress adopted a new strategy in 1990, when the 

Clean Air Act was amended. Specifically, Congress 

revised Section 112 of the Clean Air Act to mandate a 

more practical approach to reducing emissions of toxic 

air pollutants. 

This approach has two components. In the first phase, 

EPA develops regulations—MACT standards—requiring sources to meet specific emissions limits that are 

based on emissions levels already being achieved by 

many similar sources in the country. Even in its earliest 

stages, this new “technology-based” approach clearly 

produced real, measurable reductions. In the second 

phase, EPA applies a risk-based approach to assess 

how these technology-based emissions limits are 

reducing health and environmental risks. Based on this 

assessment, EPA may implement additional standards 

to address any significant remaining, or residual, health 

or environmental risks. EPA completed development of 

its strategy for addressing residual risks from air toxics 

in March of 1999. 

WHAT PROGRESS HAS BEEN 

MADE IN REDUCING TOXIC AIR 

POLLUTION? 

As of August 2000, EPA has issued 45 air toxics MACT 

standards under Section 112 of the Clean Air Act 

Amendments. These standards affect 82 categories of 

major industrial sources, such as chemical plants, oil 

refineries, aerospace manufacturers, and steel mills, as 

well as eight categories of smaller sources, such as dry 

cleaners, commercial sterilizers, secondary lead 

smelters, and chromium electroplating facilities. EPA 

6 
has also issued two standards under Section 129 of the 

Clean Air Act to control emissions, including certain 

toxic pollutants, from solid waste combustion facilities 

(one standard for municipal waste combustors and the 

other for medical waste incinerators). Together, these 

standards reduce emissions of over 100 different air 

toxics. When fully implemented, all of these standards will reduce air toxics emissions by about 

1.5 million tons per year—almost 15 times the reductions achieved prior to 1990. Each of the final rules 

developed since 1990 is summarized in an appendix to 

this document (pages 9 to 31). These summaries 

describe the sources for which final rules have been 

issued as of August 2000, the types of pollutants the 

sources emit, and how EPA’s rules are reducing their 

emissions. 

Some of these air toxics rules have the added benefit 

of reducing ground-level ozone (urban smog) and 

particulate matter. This occurs because some air toxics 

are also smog-causing volatile organic compounds 

(VOCs) (e.g., toluene) or particulate matter (e.g., 

chromium). In addition, some of the technologies and 

practices designed to control air toxics also reduce 

VOCs or types of particulate matter that are not currently among the 188 listed air toxics. Reductions of 

smog-causing pollutants and particulate matter are 

important because of the health and environmental 

problems they can cause. Most notably, urban smog 

can cause respiratory problems and can damage vegetation, and particulate matter can cause many detrimental impacts on human health, such as bronchitis, 

lung damage, increased infection, aggravation of asthma, and premature death. In addition many of these 

pollutants can contribute significantly to impaired visibility in places, such as national parks, that are valued 

for their scenic views and recreational opportunities. 

EPA has consistently worked to develop air toxics 

standards that achieve the required reductions in air 

pollution while providing regulated communities with 

as much flexibility as possible in deciding how to 

comply with the standards. For example, under a 

flexible regulation, industries may reduce their emissions by redesigning their processes, capturing and 

recycling emissions, changing work practices, or 

installing any of a variety of control technologies. 

Flexibility helps industries minimize the cost of 

compliance and encourages pollution prevention. To 

provide flexibility, EPA makes every effort to develop 

standards that are based on performance measures 

rather than specific control devices, and that allow 

for equivalent alternative control measures. 

LOOKING AHEAD 

To date, EPA has primarily focused efforts to reduce 

emissions of toxic air pollutants on technology-based 

or MACT emission standards. Over the next few years, 

EPA will continue to work with industry; environmental groups; state, local, and tribal agencies; and other 

interested groups to develop standards for the 

remaining source categories that will reduce air toxics 

emissions even further. By 2002, EPA is scheduled to 

issue 62 technology-based standards covering 96 

remaining source categories. 

EPA anticipates that its technology-based approach 

will continue to prove successful at reducing air toxics. 

Additional air toxics reductions are also expected to 

continue as a result of mobile and other stationary 

source control programs (e.g., controls to reduce 

particulate and volatile organic compound emissions) 

that indirectly reduce toxics. To identify additional 

measures beyond the technology standards that may 

be needed to protect the public health and the environment from toxic air pollutants, EPA will use a more 

risk-based focus. EPA’s efforts underway include 

national air toxics assessment activities, residual risk 

standards, evaluation of the impacts of air toxics 

deposition, data-gathering on mercury emissions 

from coal-fired electric utilities, and implementation 

of an urban air toxics strategy. These efforts are 

explained below. 

National Air Toxics Assessment 

The National Air Toxics Assessment is an ongoing 

comprehensive evaluation by EPA of air toxics in the 

United States. EPA, states, and others are working to 

improve the national toxics inventory of emissions and 

to expand air toxics monitoring networks to obtain 

more air toxics data. This work is expected to help 

focus future efforts to reduce air toxics and resultant 

health effects. 

Residual Risk Standards 

After EPA develops technology-based standards, the 

1990 Clean Air Act Amendments require EPA to assess 

7 
their effectiveness at reducing the health and environmental risks posed by air toxics. Based on this 

assessment, the Agency may implement additional 

standards that address any significant remaining, or 

“residual,” risk. After setting a MACT standard, 

EPA has 8 years (9 years for the earliest standards) 

to examine the risk posed by continued emissions 

from regulated facilities and issue requirements for 

additional controls if necessary to reduce unacceptable 

residual risk. EPA has begun to assess residual risk for 

several source categories, including coke ovens, dry 

cleaning, gasoline distribution, commercial ethylene 

oxide sterilizers, halogenated solvent cleaning, industrial cooling towers, and magnetic tape manufacturing. 

The first residual risk evaluation is scheduled to be 

completed by EPA in 2001 for the coke oven industry. 

Air Toxics Deposition to the Great Waters 

Since 1990, EPA has issued three reports to Congress on 

the deposition of air toxics and their detrimental effects 

on the Great Waters (i.e., the Great Lakes, Chesapeake 

Bay, Lake Champlain, and coastal waters). In these 

reports, EPA lists 15 pollutants of greatest concern, 

most of which have a tendency to persist in the environment and accumulate in organisms such as fish. 

The pollutants of concern are: metals (mercury, cadmium, lead), dioxins, furans, polycyclic organic matter, 

polychlorinated biphenyls (PCBs), pesticides (such as 

chlordane and DDT/DDE), and nitrogen compounds. 

Nitrogen compounds from the deposition of air toxics 

can intensify nutrient enrichment (or eutrophication) of 

coastal waterbodies. EPA’s most recent report, issued in 

2000, provides an update on atmospheric deposition of 

pollutants to the Great Waters and identifies activities that will reduce these pollutants. Several of the 

MACT standards described on pages 9 through 31 are 

expected to substantially cut emissions of mercury, 

dioxins, and other pollutants of concern to the Great 

Waters from sources such as municipal waste combustors and medical waste incinerators, which alone 

account for almost 30 percent of the mercury emissions 

and over 70 percent of the dioxin emissions nationwide 

(1990 baselines). 

Mercury Emissions from Coal-Fired 

Electric Utilities 

Mercury is one of the 188 listed toxic air pollutants. It is 

of concern because it does not degrade but persists in 

the environment. The largest emitter of mercury is 

electric utility plants (primarily coal-fired plants), 

which are estimated to emit approximately one-third of 

all manmade mercury in the United States. EPA is 

currently gathering monitoring data on mercury emissions from coal-fired electric utility plants and expects 

to complete its evaluation no later than December 2000 

on the need to reduce mercury from electric utilities. 

Integrated Urban Air Toxics Strategy 

A key component of future efforts to reduce air toxics 

is the Integrated Urban Air Toxics Strategy released by 

EPA in July 1999. The Strategy presents a framework to 

address air toxics in urban areas and builds on the 

substantial emission reductions already achieved from 

cars, trucks, fuels, and industries such as chemical 

plants and oil refineries. The Strategy outlines actions 

to further reduce emissions of air toxics and to improve 

EPA’s understanding of the health risks posed by air 

toxics in urban areas. The goals of the Strategy are to 

reduce the risk of cancer by 75 percent and to 

substantially reduce non-cancer risks associated with 

air toxics from commercial and industrial sources. 

The Strategy also reflects the need to address any 

disproportionate impacts on sensitive populations 

including children, the elderly, and minority and 

low-income communities. 

FOR FURTHER INFORMATION 

EPA Air Toxics Website 

Internet: www.epa.gov/ttn/uatw 

EPA Office of Air and Radiation 

Internet: www.epa.gov/air/ 

(202) 564-7400 

EPA Office of Transportation and 

Air Quality 

Internet: www.epa.gov/OMSWWW/ 

omshome.htm 

(202) 564-1682 

EPA Office of Chemical Emergency 

Preparedness and Prevention 

Internet: www.epa.gov/swercepp 

(800) 424-9346 

8 
Summaries of EPA’s 


Final Air Toxics MACT Rules


Over the past 10 years, EPA has issued 45 air toxics MACT standards under Section 112 of the 1990 Clean Air Act 

Amendments. These standards, listed below, are summarized on the following pages. Compliance is required within 

3 years unless otherwise specified in the rule. 

Page Standard 

10 Dry Cleaners


10 Coke Oven Batteries at Steel Plants


11 Organic Chemical Production Plants (two rules)


11 Industrial Process Cooling Towers


12 Halogenated Solvent Cleaning Machines


12 Commercial Sterilization and Fumigation Operations


13 Gasoline Distribution Facilities


13 Magnetic Tape Manufacturing


14 Chromium Electroplating and Anodizing Operations


14 Basic Liquid Epoxy Resins and Non-Nylon Polyamide Resins Manufacture


15 Secondary Lead Smelter Industry


15 Petroleum Refining Industry


16 Aerospace Manufacturing and Rework Industry


16 Marine Tank Vessel Loading Operations


17 Wood Furniture Manufacturing


17 Shipbuilding and Ship Repair Industry


18 Printing and Publishing


18 Off-Site Waste Operations


19 Elastomer Production


19 Polyethylene Terephthalate Polymer and Styrene-Based Thermoplastic Polymers Production


20 Primary Aluminum Reduction Industry


21 Pulp and Paper Mills (two rules)


22 Pharmaceutical Production


22 Flexible Polyurethane Foam Production


23 Ferroalloys Production: Ferromanganese and Silicomanganese


23 Polyether Polyols Production


24 Mineral Wool Production


24 Primary Lead Smelters


25 Phosphoric Acid Manufacturing and Phosphate Fertilizer Production (two rules)


25 Wool Fiberglass Manufacturing


26 Portland Cement Manufacturing 


27 Oil and Natural Gas Production and Natural Gas Transmission and Storage (two rules)


28 Steel Pickling


28 Pesticide Active Ingredient Production


29 Generic Rule (four rules: acetal resin production, acrylic and modacrylic fiber production, 


hydrogen fluoride production, and polycarbonate production) 

29 Publicly Owned Treatment Works 

30 Amino Resins and Phenolic Resins Production 

30 Secondary Aluminum Production 

9 
Final rule published September 22, 1993 

•	 Dry cleaning facilities are the largest source of 

perchloroethylene (also called perc) emissions in 

the United States. Because dry cleaners are located 

in many communities across the country, perc 

emissions from dry cleaners are often released in 

close proximity to large numbers of people. 

•	 Perc can cause dizziness, nausea, and headaches 

and is suspected to cause cancer in humans. 

•	 EPA’s rule requires all dry cleaners that use perc 

to implement pollution prevention measures. It 

also contains specific control requirements that 

vary depending on the type of machinery and the 

amount of perc a facility uses. 

Final rule published October 27, 1993 

•	 Coke oven batteries (a group of ovens connected 

by common walls) are used to convert coal into 

coke, which is then used in blast furnaces to convert 

iron ore to iron. 

•	 Coke oven emissions contain benzene (a known 

carcinogen) and other chemicals that can cause 

cancer of the respiratory tract, kidney, and 

prostate. Exposure to coke oven emissions can 

also cause conjunctivitis, severe dermatitis, and 

lesions of the respiratory and digestive systems. 

•	 The rule affects approximately 30,000 dry cleaners 

and will reduce perc emissions at these facilities 

by about 7,300 tons per year. 

•	 EPA’s rule provides guidelines for day-to-day 

operations and sets emissions limits for existing 

sources and even tighter limits for new sources. 

The rule was developed through a formal regulatory negotiation process that involved extensive 

industry participation. It provides industry with a 

menu of compliance options—this flexibility 

should significantly reduce compliance costs. 

•	 The coke oven rule affects 29 existing facilities 

and reduces air toxics by approximately 

1,500 tons per year. 

10 
Final rule published April 22, 1994; additional final rule published May 12, 1998, for 

Tetrahydrobenzaldehyde Production 

•	 EPA’s April 22, 1994 rule reduces emissions of 

131 organic air toxics from chemical manufacturing processes in the Synthetic Organic Chemical 

Manufacturing Industry and from several other 

chemical production processes. The rule applies 

to production of about 385 chemicals. 

•	 The rule requires reductions in toxic organic air 

pollutants emitted from 

process vents, storage 

vessels, transfer racks, 

equipment leaks, and 

wastewater treatment 

systems. 

•	 Emissions averaging is 

allowed in the rule as 

a compliance option to 

give industry flexibility 

in meeting the emissions reduction limits. 

Final rule published September 8, 1994 

•	 Industrial process cooling towers are used to 

remove heat from industrial processes. In the 

past, chromium was added to cooling tower 

waters to prevent equipment corrosion and 

control algae growth. 

•	 Chromium (Chromium VI, the most toxic form, 

is known to cause lung cancer) is ultimately 

released from the cooling towers into the air. 

Most individual industrial process cooling towers 

do not qualify as major sources of air toxics; 

however, almost all cooling towers are part of 

large production facilities (e.g., petroleum 

•	 The rule affects an estimated 310 facilities and 

will reduce air toxics emissions by 510,000 tons 

per year, a 90 percent reduction from the preregulated levels emitted by these facilities. The rule 

will also reduce VOCs by about 1 million tons 

per year, an 80 percent reduction from the preregulated levels emitted by these facilities, and 

equivalent to taking approximately 38 million cars 

off the road. 

•	 The May 12, 1998 rule added tetrahydrobenzaldehyde (THBA) to the list of Synthetic Organic 

Chemical Manufacturing Industry processes. 

THBA is used in the manufacture of paint 

additives. 

•	 Acrolein (a possible human carcinogen) and 

1,3-butadiene (a probable human carcinogen) are 

released during the THBA production process. 

•	 Currently, only one facility in the nation manufactures THBA and would have to comply with 

this rule. 

refineries, chemical manufacturing plants, and 

primary metal producers) that do qualify. 

•	 EPA’s rule prohibits the use of chromium-based 

water treatment chemicals and suggests that 

facilities substitute phosphate-based chemicals. 

•	 The rule affects an estimated 800 cooling towers 

at about 400 major sources nationwide and will 

reduce chromium emissions by 25 tons per year, 

a 100 percent reduction from the preregulated 

levels emitted by these facilities. 

11 
Final rule published December 2, 1994 

•	 Halogenated solvent cleaning machines (also 

known as degreasers) are used to clean oil and 

residues in the manufacturing and assembly of 

metal parts. Halogenated solvent cleaning is not a 

distinct industry, but it is an integral part of many 

industries, such as the aerospace and motor vehicle 

manufacturing industries. There are three basic 

types of solvent cleaning equipment: 

- Batch vapor cleaners, which heat the solvent 

to create a solvent vapor zone within which 

the parts are cleaned. 

- In-line cleaners, which are enclosed devices 

distinguished by a conveyor system used to 

supply a continuous stream of parts for cleaning. In-line cleaners include continuous web 

cleaning machines, which can clean parts such 

as film, coils, wire, and metal strips. 

- Batch cold cleaners, which use liquid solvent 

to remove soils from part surfaces. 

Final rule published December 6, 1994 

•	 A number of industries (including medical 

equipment suppliers; pharmaceutical companies; 

cosmetics manufacturers; spice manufacturers; 

libraries, museums, and archives; and contact 

sterilizers) use ethylene oxide as a sterilant for 

heat- or moisture-sensitive materials or as a 

fumigant to control microorganisms or insects. 

•	 Ethylene oxide (a probable human carcinogen 

that also can cause adverse reproductive and 

developmental effects) is released during these 

operations. 

•	 The rule applies to cleaning machines that 

use methylene chloride, perchloroethylene, 

trichloroethylene, 1,1,1-trichloroethane, carbon 

tetrachloride, chloroform, or any combination of 

these solvents in a total concentration that is 

greater than 5 percent by weight. 

•	 EPA’s rule combines equipment and work practice 

standards that emphasize pollution prevention. 

As an alternative to complying with the equipment standards option, facilities using batch 

vapor or in-line cleaning machines may demonstrate that each solvent cleaning machine emits 

less than an overall solvent emissions limit. 

•	 The rule affects an estimated 9,000 facilities 

that use solvent cleaning machines and will 

reduce air toxics emissions at these facilities by 

85,300 tons per year and VOC emissions by 

81,700 tons per year. 

•	 EPA’s rule sets ethylene oxide emissions limits for 

sterilization chamber vents, chamber exhaust 

vents, and aeration rooms. 

•	 The rule affects an estimated 114 sources and 

will reduce ethylene oxide emissions by about 

1,000 tons per year, a 94 percent reduction from 

the preregulated levels emitted by these sources. 

12 
Final rule published December 14, 1994 

•	 The gasoline distribution standard regulates bulk 

terminals and pipeline breakout stations, which 

transfer and store gasoline as it goes from petroleum refineries to service stations and gasoline 

bulk plants. 

• Approximately 10 toxic air pollulect and treat gas vapors displaced during cargo 

tank loading operations). 

•	 The rule affects an estimated 240 gasoline bulk 

terminals and 20 pipeline breakout stations. It 

will reduce air toxics emissions from these facilities by 2,300 tons per year and VOC 

tants, including benzene and emissions by over 38,000 tons per


toluene, are present in gasoline year. In addition, the collection


vapor. These pollutants are and/or prevention of gasoline evap­


released from gasoline distribu- oration under the final rule is expect­


tion facilities during tank truck ed to result in energy savings of an


and rail car loading operations, estimated 10 million gallons of gaso­


gasoline storage, and equipment line per year.


leaks. 


•	 EPA’s rule requires the use of pollution prevention methods (such 

as improving seals on storage 

tanks and inspecting equipment 

for leaks) and the use of controls 

(such as vapor processors to colFinal rule published December 15, 1994 

•	 Magnetic tape manufacturers make products 

such as audio and video cassettes and computer 

diskettes. 

•	 Toxic air pollutants are released when solvent 

mixtures are used during coating and equipment 

cleaning operations. In addition, particulate air 

toxics may be released when magnetic particles 

are transferred to the coating mixture. 

•	 EPA’s rule requires 95 percent control for most 

types of emission points, including the coating 

operations. For some of these emission points, 

EPA has developed alternative emissions standards, such as one that allows facilities the flexibility to commit to more stringent control of their 

coating operations in lieu of controlling certain 

storage tanks. 

•	 The rule affects an estimated 14 of the 25 facilities 

that manufacture magnetic tape. It will reduce 

emissions of air toxics, most of which are VOCs, 

by 2,300 tons per year. 

13 
Final rule published January 25, 1995 

•	 Chromium electroplating and anodizing operations 

coat metal parts and tools with a thin layer of 

chromium to protect them from corrosion and wear. 

Examples of electroplated parts include appliances, 

automotive parts, and large cylinders used in 

construction equipment and printing presses. 

Anodized parts include miscellaneous aircraft 

components such as wings and landing gears. 

•	 Hexavalent chromium (known to cause lung 

cancer) is released during the electroplating and 

anodizing processes. 

•	 EPA’s rule sets specific emissions limits for new and 

existing chromium electroplating and anodizing 

operations that fall into specific size categories. 

The rule requires facilities to meet emissions limits 

through the use of pollution prevention practices 

and controls. 

•	 The rule affects an estimated 1,500 hard chromium 

electroplating facilities, 2,800 decorative chromium electroplating facilities, and 700 chromium anodizing facilities. It will reduce chromium emissions by 173 tons per year, a 99 percent reduction 

from the preregulated levels emitted by these 

facilities. 

BASIC LIQUID EPOXY RESINS AND NON-NYLON POLYAMIDE 

RESINS MANUFACTURE 

Final rule published March 8, 1995 

•	 Basic liquid epoxy resins are used in the production of glues, adhesives, plastic parts, and surface 

coatings. Non-nylon polyamide or wet strength 

resins are used to improve the strength of paper. 

•	 Epichlorohydrin (strongly suspected of causing 

cancer and known to cause respiratory problems) 

is released during the resin manufacturing process. 

•	 EPA’s rule is based on an epichlorohydrin emissions 

limit, which provides facilities with the flexibility 

to meet the regulation’s requirements with a variety 

of compliance options. The rule also requires 

facilities to implement leak detection and repair 

programs. 

•	 The rule affects all three basic liquid epoxy resins 

manufacturing facilities and all nine non-nylon 

polyamide manufacturing facilities. It will reduce 

epichlorohydrin emissions by 110 tons per year. 

14 
Final rule published June 23, 1995 

•	 Secondary lead smelters produce lead from scrap 

and provide the primary means for recycling leadacid automotive batteries. The basic operations 

performed at these facilities include battery 

breaking, smelting, refining and alloying. 

•	 Secondary lead smelter facilities emit a number of 

toxic air pollutants, including 1,3-butadiene (a 

known human carcinogen) and lead compounds. 

•	 EPA’s rule requires facilities to reduce emissions 

from a number of sources, including smelting 

furnaces, kettles, dryers, and fugitive sources 

such as material handling. 

•	 The rule affects all 23 secondary lead smelters in 

the United States. It will reduce emissions of air 

toxics from these facilities by 1,400 tons per year, 

Final rule published August 18, 1995 

•	 Petroleum refineries process crude oil to produce 

automotive gasoline, diesel fuel, lubricants, and 

other petroleum-based products. 

•	 Toxic air pollutants, including benzene (a known 

human carcinogen) and toluene (known to affect 

the central nervous system and cause developmental problems), are released from storage 

tanks, equipment leaks, process vents, and wastewater collection and treatment systems at these 

facilities. 

•	 EPA’s rule requires facilities to control emissions 

from these sources. The rule allows emissions 

averaging within the petroleum refining facility, 

and provides additional flexibility by permitting 

the use of emissions averaging among emission 

points at petroleum refineries, marine terminal 

loading operations, and gasoline distribution 

facilities located at the same site. 

a 72 percent reduction from the preregulated levels 

emitted by these facilities. In addition, the rule is 

expected to reduce emissions of particulate matter 

(which can cause serious respiratory problems) 

from these facilities by 150 tons per year, and 

carbon monoxide (which can cause adverse health 

effects, including fatigue, nausea, and respiratory 

problems) by 88,000 tons per year. 

AIR TOXICS EMISSIONS 

Pre-rule 

Post-rule 540 tons 

1,940 tons 

•	 The rule affects all petroleum refineries in the 

United States and will reduce emissions of 11 air 

toxics by 53,000 tons per year, a 59 percent reduction 

from the pre-regulated levels emitted by these 

facilities. In addition, the rule is 

expected to 

reduce VOC 

emissions by over 

277,000 tons per 

year, a 60 percent 

reduction from 

preregulated levels 

emitted by these 

facilities. 

15 
Final rule published September 1, 1995 

•	 Aerospace manufacturing and rework facilities 

produce and/or repair aerospace vehicles and 

vehicle parts, such as airplanes, helicopters, 

space vehicles, and missiles. 

•	 Toxic air pollutants such as methylene chloride 

(a probable human carcinogen) and chromium 

(Chromium VI, the most toxic form, is known to 

cause lung cancer) are released from these facilities during paint stripping, cleaning, priming, 

top-coat application, and chemical milling 

maskant operations. 

•	 EPA’s rule requires facilities to eliminate most 

emissions of toxic air pollutants (particularly 

methylene chloride) from paint stripping operations 

and to implement controls that will reduce emissions of air toxics resulting from other operations. 

In addition, many reductions will be achieved 

through housekeeping actions. The final rule 

provides a variety of options for meeting these 

requirements. 

Final rule published September 19, 1995 

•	 Marine tank vessels are used to transport crude oil, 

gasoline, and toxic chemicals among refineries, bulk 

terminals, chemical plants, and pipeline terminals. 

•	 These vessels release toxic air pollutants (including 

benzene, toluene, hexane, xylene, and ethyl benzene) into the air during loading and unloading 

operations. 

•	 EPA’s rule sets limits for both air toxic pollutants 

and VOCs. It requires large marine loading terminals (i.e., terminals that load either 200 million 

•	 The rule provides industry the flexibility to meet 

the required reductions in the most cost-effective 

way, which should yield cost savings for industry 

sources. For example, the rule contains a marketbased emissions averaging provision, which 

allows facilities to overcontrol some emission 

points while undercontrolling others. 

•	 The rule affects an estimated 2,800 aerospace 

manufacturing facilities and will reduce emissions 

of air toxics and VOCs by 123,000 tons per year, a 

60 percent reduction from the preregulated levels 

emitted by these facilities. 

AIR TOXICS AND VOC EMISSIONS 

Pre-rule 

Post-rule 82,000 tons 

205,000 tons 

barrels per year of crude oil, or 10 million barrels 

per year of gasoline) to reduce emissions of VOCs 

by at least 95 percent. It also requires all other 

major sources to reduce air toxic emissions by 

97 percent. 

•	 The rule affects an estimated 30 marine tank vessel 

loading facilities. It will reduce VOC emissions 

from these facilities by approximately 43,000 tons 

per year, of which 4,500 tons are air toxics. 

16 
Final rule published December 7, 1995 

•	 The wood furniture manufacturing industry 

includes cabinet shops and facilities that make 

residential and industrial furniture. 

•	 Toxic air pollutants, including toluene, xylene, 

methanol, and formaldehyde, are released from 

these facilities during finishing, gluing, and 

cleaning operations. These air toxics can cause 

eye, nose, throat, and skin irritation; damage to 

the heart, liver, and kidneys; and reproductive 

effects. 

•	 EPA’s rule limits the amount of hazardous air 

pollutants that can be contained in the coatings 

used for finishing, gluing, and cleaning operations 

(substitutes are available that contain lower quantities of hazardous air pollutants). In addition, 

Final rule published December 15, 1995 

•	 The shipbuilding and repair industry includes 

shipyards that construct and/or repair commercial 

or military vessels, such as barges and tankers. 

•	 Toxic air pollutants such as xylene and toluene 

are released during painting and associated 

cleaning operations. 

•	 EPA’s rule, which is based on pollution prevention 

measures, requires that containers of paint and 

cleansers be kept closed, and that facilities use 

low-VOC coatings for painting and coating operations and handle solvent and paint wastes in a 

manner that minimizes spills and evaporation. 

The rule does not apply to major source facilities 

that use less than 1,000 liters (approximately 

264 gallons) of marine coatings per year, or to 

boatyards that only build or repair recreational 

vessels (marine or freshwater) less than 20 meters 

(about 66 feet) long. 

the rule contains work practice standards such as 

keeping containers closed, training workers, and 

periodically inspecting equipment to locate and 

repair leaks. 

•	 The rule affects an estimated 750 wood furniture 

manufacturing facilities and will reduce air toxics 

emissions by 33,000 tons per year (a 60 percent 

reduction from preregulated levels) and VOC 

emissions by an additional 8,400 tons per year. 

AIR TOXICS EMISSIONS 

Pre-rule 

Post-rule 

55,000 tons 

22,000 tons 

•	 The rule affects an estimated 35 shipbuilding and 

repair facilities and will reduce emissions of air 

toxics from these facilities by 350 tons per year, a 

24 percent reduction from the preregulated levels 

emitted by these facilities. 

17 
Final rule published May 30, 1996 

•	 EPA’s rule covers two distinct segments of the 

printing and publishing industry: 

- Publication rotogravure printers, which 

produce paper products such as catalogues, 

magazines, newspaper inserts, and telephone 

directories. 

- Package-product rotogravure and wide-web 

flexographic facilities that print on paper, 

plastic film, metal foil, and vinyl for use in 

products such as flexible packaging, labels, 

and gift wrap. 

•	 Toxic air pollutants (including toluene, xylene, 

methanol, and hexane) are released from the ink 

systems used by both types of printers. 

•	 For publication rotogravure facilities, EPA’s rule 

limits air toxics emissions to 8 percent of the total 

amount used (for example, facilities that use only 

hazardous-air-pollutant-based solvents would be 

required to recover 92 percent of the air toxics). 

For package-product rotogravure and wide-web 

flexographic facilities, the rule requires 95 percent 

overall control of all organic hazardous air pollutant 

emissions from their presses. 

Final rule published July 1, 1996 

•	 Off-site waste facilities include hazardous waste 

treatment, storage, and disposal facilities; industrial 

wastewater treatment facilities; solvent recycling 

facilities; and used-oil recovery facilities that 

manage hazardous air pollutant-containing materials generated at other facilities. 

•	 A number of toxic air pollutants (including 

chloroform, toluene, formaldehyde, and xylene) 

are released from tanks, process vents, equipment 

leaks, containers, surface impoundments, and 

transfer systems at these facilities. 

•	 EPA’s rule incorporates flexible compliance 

options into its emissions control requirements. 

Facilities may use pollution prevention methods 

(which allow printers to eliminate the use of toxic 

chemicals or to substitute nontoxic chemicals for 

toxic ones), traditional emissions capture and 

control equipment, or a combination of the two. 

•	 The rule affects an estimated 27 publication 

rotogravure facilities and 100 package-product 

rotogravure and wide-web flexographic facilities. 

It will reduce air toxics emissions from publication 

rotogravure printers by about 5,500 tons per year, 

and those from package-product rotogravure and 

wide-web flexographic printers by about 2,100 

tons per year. 

•	 EPA’s rule combines equipment, operations, and 

work practice standards. For example, the rule 

requires that containers be covered and that 

process vents meet 95 percent organic emission 

controls. 

•	 The rule affects an estimated 250 off-site waste 

operation facilities. It will reduce air toxics 

emissions by 43,000 tons per year and VOC 

emissions by 52,000 tons per year. 

18 
Final rule published September 5, 1996 

•	 Elastomers are used in the production of many 

synthetic rubber products, including tires, hoses, 

footwear, adhesives, wire insulation, floor tiles, 

and latexes. 

•	 A number of toxic air pollutants (such as styrene, 

hexane, and toluene) are released during the initial 

stages of the elastomer manufacturing process. 

•	 EPA’s rule encourages the use of pollution prevention techniques to reduce the amount of air 

toxics released during elastomer production. The 

rule sets emissions limits for several specific 

emission points—storage tanks, process vents, 

equipment leaks, and wastewater systems. It also 

contains a market-based emissions averaging provision that allows facilities to overcontrol some 

emissions points while undercontrolling others, 

thus achieving the required reductions in the 

most cost-effective manner possible. 

•	 The rule affects 36 facilities nationwide and will 

reduce air toxics emissions by approximately 

6,400 tons annually, a 50 percent reduction from 

current levels. 

AIR TOXICS EMISSIONS 

Pre-rule 

Post-rule 6,400 tons 

12,800 tons 

•	 EPA developed the rule in partnership with 

industry representatives and other major stakeholders. The Agency estimates that new facilities 

will experience annual cost savings of about 

$5 million under the rule, due to pollution prevention measures. 

•	 The rule affects 66 facilities nationwide and will 

reduce emissions by approximately 3,880 tons 

annually, a 20 percent reduction from current levels. 

AIR TOXICS EMISSIONS 

Pre-rule 19,400 tons 

Post-rule 15,520 tons 

POLYETHYLENE TEREPHTHALATE POLYMER AND STYRENEBASED THERMOPLASTIC POLYMERS PRODUCTION 

Final rule published September 12, 1996 

•	 Polyethylene terephthalate polymers and styrenebased thermoplastics are used in the manufacture 

of such products as polyester fibers, soft drink 

bottles, plastic automotive parts, packing materials, 

and plastic toys. 

•	 A number of toxic pollutants (including styrene, 

butadiene, and methanol) are released into the air 

during polymer production. 

•	 To reduce the amount of air toxics released from 

polymer production facilities, EPA’s rule sets 

emissions limits for several emissions points: 

storage vessels, process vents, equipment leaks, 

and wastewater operations. The rule also limits 

releases from process contact cooling towers at 

some existing and new facilities. 

19 
Final rule published October 7, 1997 

•	 Primary aluminum reduction plants produce 

molten aluminum metal (virgin aluminum) from 

alumina ore. Typically, primary aluminum plants 

are components of larger facilities that prepare a 

variety of finished products. These larger facilities 

also typically include secondary aluminum plant 

operations, which use aluminum metal to make 

products such as cans, aircraft and automotive 

products, and construction materials. Standards 

for secondary aluminum production are covered 

under a separate rule, summarized on page 30. 

•	 Air toxics released during the production of 

molten aluminum metal include hydrogen fluoride 

(which can cause serious respiratory damage) 

and polycyclic organic matter (which is strongly 

suspected of causing cancer and other serious 

health effects). 

•	 Developed in partnership with state regulators, 

industry stakeholders, and tribal governments, 

EPA’s final rule contains an emissions averaging 

provision that allows facilities to overcontrol 

some emissions points while undercontrolling 

others, thus achieving the required reductions in 

the most cost-effective manner possible. As a further 

cost-saving incentive, facilities that consistently 

perform below the levels set in the standard will 

be allowed to reduce the frequency of sampling 

or emissions testing. 

•	 To achieve the required reductions, the final rule 

relies on a combination of pollution prevention 

measures, including work practices, equipment 

modifications, operating practices, housekeeping 

measures, and in-process recycling. 

•	 The rule affects 24 facilities nationwide. It will 

reduce fluoride emissions by about 3,700 tons per 

year, polycyclic organic matter emissions by 

about 2,000 tons per year, and particulate matter 

emissions by 16,000 tons per year. These emission 

levels represent a reduction of approximately 

50 percent from preregulated levels. 

FLUORIDE EMISSIONS 

Pre-rule 

Post 3,700 tons -rule 

7,400 tons 

PARTICULATE MATTER 

EMISSIONS 

Pre-rule 

Post-rule 16,000 tons 

32,000 tons 

POLYCYCLIC ORGANIC MATTER 

EMISSIONS 

Pre-rule 

Post-rule 2,000 tons 

4,000 tons 

20 
Two final rules published April 15, 1998 

•	 Wood and non-wood fiber sources such as cotton, 

linen, and straw are turned into pulp either 

though cooking via chemicals (known as digestion), mechanical grinding, or a combination of 

both. Following digestion or grinding, the resulting 

fibrous mass is washed, screened, and (depending 

on the final product) sometimes bleached. 

•	 A number of toxic air pollutants (including 

chloroform, chlorine, formaldehyde, methanol, 

acetaldehyde, methyl ethyl ketone, and metals) 

are released during cooking, washing, bleaching, 

and chemical recovery processes at these facilities. 

•	 EPA’s air toxics rules are part of an integrated, 

multimedia regulation designed to control pollutant 

releases to the water and air. The integrated rules 

allow the pulp and paper industry to consider all 

regulatory requirements at one time in order to 

select the most effective pollution prevention and 

control technologies. 

•	 EPA has issued two final air toxics standards for 

the pulp and paper industry that cover emissions 

from pulping and bleaching processes at mills 

that chemically pulp wood, and certain bleaching 

processes at non-wood, mechanical, and 

secondary fiber mills. These standards do not 

require controls on paper machines at any mills 

and on pulping operations at non-wood, 

mechanical, and secondary fiber mills. 

•	 The final rules will affect approximately 155 

mills and will reduce air toxics emissions by 

155,000 tons per year, a 60 percent reduction 

from current levels. The rules will also reduce 

VOC emissions by 450,000 tons per year and 

total sulfur emissions by 86,000 tons per year. 

AIR TOXICS EMISSIONS 

(FINAL RULES) 

Pre-rule 

Post-rule 

258,000 tons 

103,000 tons 

21 
Final rule published September 21, 1998 

•	 Pharmaceutical production includes operations 

such as chemical synthesis, formulation, and 

natural extraction, used to produce drugs and 

medications. 

•	 The production of pharmaceuticals results in the 

release of a number of air toxics, including methylene chloride, methanol, toluene, and hydrogen 

chloride. 

•	 This rule, developed in partnership with representatives from industry and states, provides a 

variety of compliance options. Facility operators 

may choose to meet either emission limits or control efficiency requirements for storage tanks and 

process vents. Operators may elect to comply 

with the pollution prevention alternative in lieu 

of the standards for process vents, storage tanks, 

Final rule published October 7, 1998 

•	 This rulemaking affects only flexible polyurethane 

foam that is manufactured at slabstock, molded, 

and rebond polyurethane production facilities. 

These segments of the industry manufacture 

cushions, bedding materials, and other speciality 

products. 

•	 The production of flexible polyurethane foam 

results in the release of air toxics, primarily 

methylene chloride, which is a probable human 

carcinogen that can adversely affect the central 

nervous system. 

•	 This rule is based on pollution prevention techniques and flexible requirements. A variety of compliance options are available to facility operators. As 

a result of the rule, the use of methylene chloride at 

molded foam production facilities will be 

eliminated. 

equipment leaks, and wastewater where the operator has reduced the hazardous air pollutant usage 

for a product process. 

•	 Approximately 100 pharmaceutical production 

facilities nationwide will be affected by this rule. 

When fully implemented, the rule will reduce 

air toxics emissions by 24,000 tons annually, 

a 65 percent reduction from current levels. 

AIR TOXICS EMISSIONS 

Pre-rule 

Post-rule 12,900 tons 

36,900 tons 

•	 Approximately 78 slabstock, 98 molded, and 

21 rebond foam facilities nationwide will be 

affected by this rule. When fully implemented, 

the rule will reduce air toxics emissions by 

11,500 tons annually at slabstock foam facilities 

(a 68 percent reduction from current levels), and 

by 2,300 tons annually at molded foam facilities 

(a 98 percent reduction from current levels). All 

rebond foam facilities are believed to be in compliance with this rule; therefore, no further 

reductions are expected. 

AIR TOXICS EMISSIONS— 

SLABSTOCK AND MOLDED 

FOAM FACILITIES 

P

5,447 tons 

re-rule 

Post-rule 

19,247 tons 

22 
FERROALLOYS PRODUCTION: 

FERROMANGANESE AND SILICOMANGANESE 

Final rule published May 20, 1999 

•	 A ferroalloy is a mixture of iron and one or more 

other elements, such as chromium, manganese, 

or silicon. Ferroalloys are primarily used in the 

manufacturing of steel and cast iron products 

with enhanced or special properties. 

•	 The production of ferroalloys results in the 

release of a number of metallic air toxics, 

including manganese. The variety and quantity of 

pollutants emitted are related to the amount of 

metals present in the raw materials. Manganese 

can adversely affect human health. For example, 

chronic exposure to high levels of manganese 

primarily affects the central nervous system. 

Final rule published June 1, 1999 

•	 Polyether polyols are used as an ingredient in 

lubricants, adhesives, cosmetics, soaps, and 

polymers for urethane production. 

•	 A number of air toxics are released during the 

production of polyether polyols. These include 

ethylene oxide, propylene oxide, toluene, and 

hexane, all of which can cause cancer or other 

adverse health effects. 

•	 EPA’s rule establishes emission limits and control 

efficiency requirements for storage tanks, process 

vents, equipment leaks, and wastewater 

treatment systems. For several of the emission 

units, industry can choose from a number of 

compliance approaches. 

•	 This final rule sets limits for particulate emissions 

from one ferromanganese and silicomanganese 

production plant. Particulate matter is used as a 

surrogate for the air toxic manganese emitted 

from this facility. Particulate control devices are 

known to remove metallic pollutants with 

essentially the same efficiency as they remove 

particulates. 

•	 The facility already has control equipment in place 

to comply with EPA’s rule. This equipment 

reduces air toxics emissions by 99 percent from 

uncontrolled levels. The rule is not expected to 

bring about additional reductions, but will ensure 

continued use and good operation of existing 

control equipment. 

•	 Of the 80 facilities affected by this rule, roughly 

half have already installed emission control 

devices. When fully implemented, the rule will 

reduce air toxic emissions by approximately 

2,000 tons annually, a reduction of 50 percent 

from current levels. 

AIR TOXICS EMISSIONS 

Pre-rule 

Post-rule 2,000 tons 

4,000 tons 

23 
Final rule published June 1, 1999 

•	 Mineral wool is made by melting natural rock, 

blast furnace slag, and other materials in a furnace 

known as a cupola, and then forming the molten 

material into a fiber. Depending on the final 

product, an oil or a phenol/formaldehyde-based 

binder is applied. Fiber to which oil has been 

applied is then sized and bagged or baled. Fiber 

to which a phenol/formaldehyde-based binder 

has been applied is thermoset in a curing oven 

and cooled. 

•	 Mineral wool is used as an industrial and structural 

insulator. It is also added to other products to 

provide structural strength, sound absorbency, or 

fire protection. 

•	 Production of mineral wool can lead to releases of a 

variety of air toxics, including arsenic (a known 

human carcinogen) and beryllium, cadmium, lead, 

and formaldehyde (probable human carcinogens). 

•	 EPA’s rule requires facilities to reduce air toxics 

emissions from existing and new cupolas, using 

particulate matter as a surrogate for the metallic 

toxics (e.g., arsenic, beryllium, cadmium, lead). 

Additionally, facilities must reduce emissions of 

Final rule published June 4, 1999 

•	 Primary lead smelters process lead ore to produce 

lead metal. The majority of this lead is then used 

to manufacture lead-acid batteries. 

•	 A variety of air toxics are released during primary 

lead smelting operations. These include lead, 

arsenic, antimony, and cadmium. 

•	 EPA’s rule will control emissions by setting plantwide lead emission limits. These limits are based 

on pre-existing limits established by the states in 

which affected facilities are located. The rule gives 

owners and operators the flexibility to determine 

how and to what extent each source is controlled 

to achieve the required emission limits. The rule 

carbonyl sulfide from new cupolas, using carbon 

monoxide as a surrogate for carbonyl sulfide. The 

rule also requires reduction of phenol and 

formaldehyde emissions from curing ovens. 

•	 The rule allows flexibility by offering a choice of 

compliance options (emission limits or percent 

reduction standards). The rule’s use of surrogate 

pollutants will also help reduce monitoring and 

emission testing costs. 

•	 The rule will affect 15 mineral wool production 

facilities nationwide. When fully implemented, it 

will reduce air toxics and particulate matter emissions from cupolas, and formaldehyde and phenol emissions from curing ovens, by 260 tons 

annually, a reduction of 76 percent. 

AIR TOXICS EMISSIONS 

Pre-rule 

Post-rule 82 tons 

342 tons 

also details several work practice requirements for 

the control of fugitive dust, and the operation and 

maintenance of air pollution control equipment. 

•	 Three manufacturing facilities will be affected by 

this rule. The emissions limits are based on preexisting state emissions limits. As such, no direct 

emissions reduction can be estimated based solely 

on the emissions limits. EPA expects that as a 

result of following the fugitive dust work practice 

and monitoring requirements, facilities will 

achieve air toxics emission reductions by improving equipment performance and reducing the 

potential for fugitive dust emissions. 

24 
PHOSPHORIC ACID MANUFACTURING 

AND PHOSPHATE FERTILIZER PRODUCTION 

Two final rules published June 10, 1999 

•	 Phosphoric acid is used in the production of 

phosphate-based fertilizers, which are used for 

farming and other agricultural purposes. 

•	 A variety of air toxics can be released to the 

atmosphere during the production of phosphoric 

acid and phosphate fertilizers. 

•	 EPA’s rules require facilities to reduce emissions 

of air toxics from the following emissions points: 

wet process phosphoric acid plants, superphosphoric acid plants, purified phosphoric acid 

plants, phosphate rock dryers, phosphate rock 

calciners, mono- and di-ammonium phosphate 

fertilizer plants, and granular triple superphosphate 

fertilizer plants and storage buildings. The rules 

are structured to limit emissions across process 

lines that include several different emissions 

points. The rules establish a single limit for each 

process line, allowing facilities the flexibility to 

Final rule published June 14, 1999 

•	 Wool fiberglass is a constituent of a variety of 

insulation products, including building and pipe 

insulation. It is produced from sand, feldspar, 

sodium sulfate, anhydrous borax, boric acid, and 

other materials. 

•	 A variety of air toxics are released to the atmosphere during the production of wool fiberglass. 

These include arsenic (a known human carcinogen), and lead and formaldehyde (probable 

human carcinogens). 

•	 EPA’s rule applies to the following types of facilities: 

glass manufacturing furnaces, rotary spin manufacturing lines producing building insulation, 

flame attenuation (FA) manufacturing lines 

producing pipe products, and FA manufacturing 

lines producing heavy-density insulation 

operate and control each line in the most efficient 

manner while still achieving specific emission 

reductions. 

•	 The rules affect an estimated 21 facilities. The 

rules will reduce emissions of toxic air pollutants 

(primarily hydrogen fluoride) by approximately 

345 tons per year, a 57 percent reduction from 

current levels. They will also reduce emissions of 

total fluorides by 1,035 tons per year, and will yield 

small reductions in emissions of heavy metals. 

Total fluorides are known to damage vegetation 

and have other adverse effects on the environment. 

AIR TOXICS EMISSIONS 

Pre-rule 

Post-rule 260 tons 

605 tons 

products. The rule also contains new emission 

test methods for measuring formaldehyde. 

•	 The rule provides owners and operators flexibility 

in meeting the emission limits by encouraging 

process modifications and pollution prevention 

techniques, instead of more costly add-on controls. 

•	 Of the 27 facilities currently manufacturing wool 

fiberglass nationwide, 21 will be affected by this 

rule. The rule will reduce emissions of formaldehyde by 580 tons annually, a reduction of 30 percent. 

The rule will also reduce particulate matter 

emissions by 840 tons per year and emissions 

of toxic metals (including arsenic, chromium, 

and lead) by 20 pounds per year—a reduction of 

30 percent from current levels. 

25 
Final rule published June 14, 1999 

•	 Portland cement is manufactured by grinding 

and heating a mixture of raw materials (e.g., 

limestone, clay, iron ore) in a rotary kiln. The kiln 

is fired by a variety of fuels, including coal, oil, 

gas, coke, and/or various waste materials. After 

firing, the product (called clinker) is cooled and 

then mixed with gypsum to produce portland 

cement. 

•	 A number of harmful air pollutants, including air 

toxics, particulate matter, and hydrocarbons, are 

released during portland cement manufacturing. 

Most of these result from fuel combustion in the 

kiln and from heating and handling of raw 

materials. The health impacts of these pollutants 

include an increased risk of respiratory and 

cardiovascular diseases and cancer. 

•	 This rule sets emission limits for kilns, clinker 

coolers, and materials handling facilities, and 

includes new emission measurement methods. 

In complying with this rule, facility owners and 

operators have the flexibility to determine how 

emission limits will be met. 

•	 Approximately 110 portland cement manufacturing facilities nationwide will be regulated under 

this rule. The rule will reduce air toxics emissions 

by approximately 90 tons per year (a 31 percent 

reduction), particulate matter emissions by 

4,200 tons annually (a 17 percent reduction), 

and hydrocarbons emissions by 220 tons annually 

(a 38 percent reduction). 

AIR TOXICS EMISSIONS


Pre-rule 

Post-rule 

290 tons 

200 tons 

PARTICULATE MATTER 

EMISSIONS 

Pre-rule 

Post-rule 

24,800 tons 

20,600 tons 

HYDROCARBONS EMISSIONS


Pre-rule 

Post-rule 

580 tons 

360 tons 

26 
OIL AND NATURAL GAS PRODUCTION AND NATURAL GAS 

TRANSMISSION AND STORAGE 

Two final rules published June 17, 1999 

•	 Emissions of air toxics from oil and natural gas 

production and natural gas transmission and 

storage occur during separation, upgrade, transport, and storage of crude oil, condensate, natural gas, and related products. Emissions also 

occur as a result of vapor leaks from pumps, compressors, valves, flanges, and other equipment. 

•	 The affected facilities can release a variety of air 

toxics, including benzene (a known human carcinogen) and other volatile organic compounds 

(VOCs) suspected to cause cancer or other serious 

health effects such as birth defects or reproductive effects. VOCs also contribute to the formation 

of ground-level ozone, the primary constituent of 

smog. In addition, the affected facilities can 

release methane, a potent greenhouse gas. 

•	 EPA’s rules require controls for the following 

emission points at oil and natural gas production 

facilities: process vents at some glycol 

dehydration units, tanks with flashing emission 

potential, and some fugitive emission sources. 

Natural gas transmission and storage facilities 

will be required to control emissions from process 

vents at some glycol dehydration units. 

•	 In an effort to increase flexibility, EPA is encouraging facility owners and operators to use pollution 

prevention techniques to reduce emissions from 

process vents at glycol dehydration systems—the 

largest single air pollutant emission point at 

oil and natural gas production facilities. 

•	 The oil and natural gas production rule will 

affect approximately 440 facilities nationwide. It 

will reduce air toxics emissions by an estimated 

31,000 tons annually (a 43 percent reduction), 

VOC emissions by 67,000 tons annually 

(a 45 percent reduction), and methane emissions 

by 7,700 tons annually (a 33 percent reduction). 

•	 The natural gas transmission and storage rule 

will affect approximately seven facilities nationwide. It will reduce air toxics emissions by an 

estimated 430 tons annually (an 18 percent 

reduction), VOC emissions by 610 tons annually 

(a 19 percent reduction), and methane emissions 

by 250 tons annually (a 19 percent reduction). 

AIR TOXICS EMISSIONS— 

OIL AND NATURAL GAS 

PRODUCTION 

Pre-rule 72,000 tons 

Post-rule 41,000 tons 

1,970 tons 

AIR TOXICS EMISSIONS— 

NATURAL GAS TRANSMISSION 

AND STORAGE 

Pre-rule 2,400 tons 

Post-rule 

27 
Final rule published June 22, 1999 

•	 Steel pickling is a process in which an acid 

solution is used to remove the oxide scale that 

forms on steel as it cools from a molten state. 

•	 Hydrochloric acid and chlorine can be released to 

the atmosphere during the steel pickling process. 

Hydrochloric acid is emitted from processing 

tanks used in continuous and batch pickling lines, 

from acid regeneration plants, and from storage 

tanks containing virgin or regenerated acid. 

Chlorine is emitted from acid regeneration plants. 

•	 Chronic exposure to hydrochloric acid can cause 

inflammation of the stomach, respiratory system, 

and skin, as well as sensitivity to sunlight. Acute 

exposure to high levels of chlorine can result in 

vomiting, chest pain, lung problems, and even 

death. At lower levels, chlorine is a potent irritant 

to the eyes, the upper respiratory tract, and the 

lungs. 

•	 EPA’s rule establishes limits for hydrochloric acid 

emissions from pickling lines, acid regeneration 

plants, and acid storage tanks. It also establishes 

Final rule published June 23, 1999 

•	 Pesticide active ingredients (PAIs) are used in the 

manufacture of insecticide, herbicide, and 

fungicide products. These products are typically 

used in the agricultural industry for treating 

insects, rodents, weeds, and other pests. 

•	 A variety of air toxics, including toluene, methanol, 

and hydrochloric acid, can be released to the 

atmosphere during production of PAIs. 

•	 EPA’s rule affects the following points in the PAI 

production process: process vents, storage vessels, 

wastewater and associated treatment residuals, 

limits for chlorine emissions from acid regeneration 

plants. The rule offers flexibility to facility 

operators by providing cost-effective options for 

both emissions control and monitoring. 

•	 This rule will affect approximately 62 steel 

pickling plants and 8 acid regeneration plants. 

When fully implemented, the rule will reduce 

hydrochloric acid emissions by approximately 

2,500 tons per year (a 76 percent reduction from 

current levels) and chlorine emissions by 8.2 tons 

per year (a 30 percent reduction from current 

levels). The controls required by this rule will 

also reduce particulate matter emissions. 

HYDROCHLORIC ACID 

EMISSIONS 

Pre-rule 

Post 800 tons -rule 

3,300 tons 

heat exchange systems, and certain types of equipment. The rule allows facilities the flexibility to 

meet emissions limits for process vents by using 

either an add-on control device or a pollutionprevention alternative. 

•	 Currently, there are approximately 78 PAI 

production facilities that will be affected by this 

rule. When fully implemented, the rule will 

reduce emissions of air toxics by approximately 

2,755 tons per year, a 65 percent reduction from 

current levels. 

28 
GENERIC RULE 

FOR ACETAL RESIN PRODUCTION, ACRYLIC AND MODACRYLIC FIBER PRODUCTION, 

HYDROGEN FLUORIDE PRODUCTION, AND POLYCARBONATE PRODUCTION 

Four final rules published June 29, 1999 

•	 These rules set technology-based emission limits 

for several categories that have five or fewer facilities nationwide. 

•	 The facilities regulated by these rules manufacture a variety of components, including thermoplastics used in industrial applications and 

commercial articles; synthetic fibers used in the 

textile, sporting goods, and aviation industries; 

polycarbonates used in electrical components and 

automotive parts; and fluoride compounds. 

Final rule published October 26, 1999 

•	 Publicly owned treatment works (POTW) treat 

wastewater received from residential, commercial, 

and industrial sources. POTW can release air 

toxics in the form of volatile organic compounds 

in wastewater. 

•	 The primary air toxics emitted by POTW include 

xylenes, methylene chloride, toluene, ethyl benzene, chloroform, tetrachloroethylene, benzene, 

and naphthalene. Each of these air toxics can 

cause adverse health effects provided sufficient 

exposure. For example, exposure to methylene 

chloride (a probable human carcinogen) can 

adversely affect the central nervous system, while 

benzene is known to cause cancer in humans. 

•	 EPA’s rule will reduce air toxics emissions from 

new or reconstructed POTW that are major 

sources of air emissions. EPA is not requiring 

additional controls on existing POTW. 

•	 Some POTW treat wastewater from industrial 

sources whose waste streams are already regulated by industrial air toxics rules. By treating their 

regulated waste streams at a POTW, these industrial sources are able to comply with these other 

•	 A variety of air toxics are sometimes released to 

the atmosphere during the manufacture of these 

products. These air toxics include formaldehyde, 

methanol, and the volatile organic compounds 

methylene chloride, ethyl chloride, and phosgene. 

•	 EPA’s rules will control emissions for all of the 

categories at similar phases of the manufacturing 

process. These phases include storage tanks, 

process vents, equipment leaks, and wastewater. 

•	 The rules will ensure that the nine affected 

facilities maintain or develop emission controls. 

air toxics rules. Under the new POTW rule, plants 

that treat regulated waste streams from industrial 

sources are classified as industrial POTW. All 

other treatment plants are classified as nonindustrial POTW. 

•	 Under EPA’s rule, new or reconstructed nonindustrial POTW will need to either include air 

pollution controls on certain wastewater treatment units or demonstrate through pollution 

prevention techniques an equivalent reduction 

in emissions. New or reconstructed industrial 

POTW must comply with the non-industrial 

standards, or with all other air toxics regulations 

applicable to the industrial sources whose wastewater they are treating, whichever is more stringent. 

•	 EPA estimates that 20 to 30 non-industrial POTW 

would need to control air toxics emissions if they 

elected to reconstruct their existing facilities or 

build a new facility. EPA estimates that fewer 

than five POTW currently meet the definition of 

industrial POTW. The rule is not expected to 

require additional reductions from these sources. 

29 
Final rule published January 20, 2000 

•	 Amino/phenolic resins are primarily used in the 

manufacture of plywood, particle board, adhesives, wood furniture, and plastic parts. 

•	 A number of toxic air pollutants, including 

formaldehyde (a probable human carcinogen), 

phenol, methanol, xylene, and toluene, are 

released during the resin manufacturing process. 

•	 EPA’s rule establishes emission limits or control 

efficiency requirements for several emission 

points: reactor batch process vents, non-reactor 

batch process vents, continuous process vents, 

Final rule published March 23, 2000 

•	 Secondary aluminum plants recover aluminum 

from beverage cans, foundry returns, and other 

aluminum scrap. These facilities release air toxics 

during both preprocessing operations (such as 

aluminum scrap shredding, drying, and decoating) and furnace operations (such as aluminum 

melting, refining, and alloying). 

•	 Secondary aluminum plants emit a variety of 

toxic air pollutants. These air toxics may include 

up to 11 metals, organic compounds, and acid 

gases such as hydrogen chloride and chlorine. 

The health effects associated with exposure to 

these air toxics can include cancer, respiratory 

irritation, and damage to the nervous system. 

•	 EPA’s rule establishes emission standards for 

metals, dioxin/furans, organic hazardous air 

pollutants, and acid gases for larger secondary 

aluminum plants. The rule also establishes 

standards for dioxin/furan emissions from 

smaller secondary aluminum plants. 

•	 Affected sources can achieve the emission 

reductions required by the rule through the use 

of pollution-control equipment and/or through 

a variety of pollution-prevention measures, 

storage tanks, equipment leaks, and heat exchange 

systems. The rule encourages the use of pollution 

prevention measures and provides flexibility by 

allowing the use of a variety of control strategies 

rather than specific control devices. 

•	 The rule affects new and existing amino/phenolic 

resin manufacturing facilities. EPA has identified 

100 existing facilities that may be affected. The 

rule will reduce air toxics emissions by approximately 360 tons per year, a 51 percent reduction 

from 1992 levels. 

including work practices and operating practices. 

The rule provides flexibility to the industry by 

offering alternative compliance and monitoring 

options. To reduce monitoring and emissions 

testing costs, the rule uses particulate matter as 

a surrogate for metals, total hydrocarbons as a 

surrogate for organics, and hydrogen chloride 

as a surrogate for total emissions of hydrogen 

chloride, chlorine, and hydrogen fluoride. 

•	 The rule will affect 80 large secondary aluminum 

plants. Hundreds of smaller plants may be subject to limitations on emissions of dioxin/furans. 

The rule will reduce nationwide emissions of air 

toxics by about 12,420 tons per year, a reduction 

of nearly 70 percent from current levels. In particular, hydrogen chloride emissions will be reduced 

by about 12,370 tons per year or by 73 percent, 

and emissions of metals will be reduced by about 

40 tons per year, a reduction of over 60 percent 

from current levels. 

30 
Summaries of Related Solid Waste 

Incineration Rules 

EPA has also issued final rules to control emissions of certain air toxics from solid waste combustion facilities. These rules 

set emissions limits for new solid waste combustion facilities and provide emissions guidelines for existing solid waste combustion facilities under Section 129 of the Clean Air Act. 

Final rule published December 19, 1995; amended August 25, 1997 

•	 Municipal waste combustors include incinerators 

that burn waste and waste-to-energy plants that 

generate energy from garbage. EPA’s final rule 

applies to all municipal waste combustion units 

with the capacity to burn more than 250 tons of 

garbage per day (known as large municipal waste 

combustion units; EPA has initiated development of 

rules for small municipal waste combustion units). 

•	 Municipal waste combustors release a number of 

pollutants, including cadmium, lead, mercury, 

dioxin, sulfur dioxide, hydrogen chloride, nitrogen 

dioxide, and particulate matter. Dioxin and mercury 

are of particular concern because they are toxic, 

persist in the environment, and bioaccumulate. 

Final rule published September 15, 1997 

•	 Hospital, medical, and infectious waste is solid 

waste produced in the diagnosis, treatment, or 

immunization of humans or animals; it includes 

needles, gauzes, boxes, and packaging materials. 

Fewer than half of all hospitals and a small number 

of nursing homes, pharmaceutical research laboratories, and veterinary clinics use incinerators to 

dispose of their waste. 

•	 A number of toxic air pollutants, including dioxins, 

mercury, lead, and cadmium, are released into the 

air during the incineration process. 

•	 EPA’s rule contains one set of emission requirements for new incinerators and another set for 

existing incinerators. The rule establishes emissions 

•	 EPA’s rule contains strict MACT-based standards 

for new incinerators and emissions limits for 

existing incinerators. 

•	 The rule affects an estimated 164 municipal waste 

combustion units and will significantly reduce air 

toxics emissions (dioxins, lead, cadmium, and 

mercury). The rule will reduce dioxin emissions 

by 99 percent and mercury emissions by 90 percent, 

compared with 1990 emissions levels from these 

sources. Overall emissions of other air pollutants 

(including sulfur dioxide, particulate matter, 

nitrogen oxides, and hydrogen chloride) will be 

reduced by more than 90,000 tons per year. 

limits for nine pollutants (including dioxin, lead, 

cadmium, and mercury). It requires training of 

incinerator operators and establishes requirements 

for appropriate siting of new incinerators. 

•	 The rule affects an estimated 2,400 existing incinerators and will reduce air toxics emissions (dioxins, 

lead, cadmium, and mercury) by more than 

25 tons per year. Dioxins will be reduced by over 

90 percent from the current levels emitted by 

these incinerators. The rule will also reduce other 

air pollutant emissions (particulate matter, carbon 

monoxide, and hydrogen chloride) by over 

7,000 tons per year. 

31