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Mobile Source Air Toxics
This page presents information on mobile source air toxics and strategies for reducing risk to the public from these pollutants.
- What are Mobile Source Air Toxics?
- What is EPA Doing About Mobile Source Air Toxics?
- What You Can Do
- Assessment
- Regulations
- Reducing Risk in Communities
Archive for Mobile Source Air Toxics
NOTE: You will need Adobe Acrobat Reader, available as a free download, to view some of the files on this page. See EPA's PDF page to learn more about PDF, and for a link to the free Acrobat Reader.
What Are Mobile Source Air Toxics?
Mobile source air toxics are compounds emitted from highway vehicles and nonroad equipment which are known or suspected to cause cancer or other serious health and environmental effects.
- Fact Sheet: Air Toxics from Motor Vehicles (PDF) (5 pp, 13K, EPA400-F-92-004, August 1994)
- EPA has conducted an extensive review of the literature to produce
a list of the compounds identified in the exhaust or evaporative
emissions from onroad and nonroad equipment, using baseline as
well as alternative fuels (e.g., ethanol, biodiesel, compressed natural
gas). This list, the Master List of Compounds Emitted by Mobile
Sources, and the documentation for the development of the list
are available here:
- Master List of Compounds Emitted by Mobile Sources (Excel, 725K)| PDF Version (16 pp, 1.5MB, EPA420-B-06-002)
- Final Report Master List prepared by ENVIRON International Corporation (PDF) (58 pp, 717K, EPA420-R-06-005, February 2006)
- Air Quality Planning
and Standards: EPA maintains a valuable online resource center
for information regarding air quality, toxic air pollutants, health
effects, technical reports, assessment data, regulations, and
air quality programs. Particular areas of interest are:
- About Air Toxics, Health, and Ecological Effects provides a wealth of information on health and ecological effects of air toxic pollutants.
- Health Effects Notebook for Hazardous Air Pollutants provides detailed information about the health effects of hazardous air pollutants (HAPs) available in separate fact sheets, for nearly every HAP specified in the Clean Air Act Amendments of 1990.
What is EPA Doing About Mobile Source Air Toxics?
In February 2007, EPA finalized a rule to reduce hazardous air pollutants from mobile sources (Control of Hazardous Air Pollutants from Mobile Sources, February 9, 2007). The rule will limit the benzene content of gasoline and reduce toxic emissions from passenger vehicles and gas cans. EPA estimates that in 2030 this rule would reduce total emissions of mobile source air toxics by 330,000 tons and VOC emissions (precursors to ozone and PM2.5) by over 1 million tons.
By 2010, EPA's existing programs will reduce mobile source air toxics by over one million tons from 1999 levels. In addition to controlling pollutants such as hydrocarbons, particulate matter, and nitrogen oxides, EPA's recent regulations controlling emissions from highway vehicles and nonroad equipment also result in large air toxic reductions. Furthermore, EPA has programs under development that would provide additional benefits from further controls for small nonroad gasoline engines and diesel locomotive and marine engines. Finally, EPA has developed a variety of programs to reduce risk in communities, such as Clean School Bus USA, the Voluntary Diesel Retrofit Program, and National Clean Diesel Campaign.
What You Can Do?
EPA has developed a variety of information materials on how you can help reduce emissions and exposure to air pollutants from mobile sources.
Assessment
- Risk
- Emissions
- Air Quality & Exposure Monitoring
- Health Effects
- Modeling & Analysis Tools
- Technical Analysis Plan
Risk
- National-Scale Air Toxics Assessment for 1999 includes 177 air toxics, a subset of the air toxics on the Clean Air Act's list of 187 air toxics, as well as diesel particulate matter, an indicator of diesel exhaust.
- Philadelphia Toxic Air Pollutants Risk Reduction Project: EPA and Philadelphia Air Management Services are conducting a joint project called the "Philadelphia Toxic Air Pollutants Risk Reduction Project" to help reduce the threat to their health which Philadelphia's residents face from exposure to air toxics.
- Portland,
Oregon Air Toxics Assessment:
EPA is helping to support this refined local scale assessment
led by the Oregon Department of Environmental Quality.
Emissions
- National Toxics Inventory Data and Documentation provides county level inventory data for on-highway vehicles, nonroad sources, aircraft, commercial marine vessels, and locomotives.
Air Quality and Exposure Monitoring
- Air Toxics Monitoring centers around the exchange of air toxics monitoring-related information.
- California
Air Resources Board School Bus Study was conducted to characterize the range of children's exposures
to air toxics during their school bus commute.
Health Effects
- Integrated Risk Information System (IRIS) features a database of human health effects that may result from exposure to various substances found in the environment.
- Health
Assessment Document for Diesel Exhaust includes the final
health assessment document that examines information regarding
the possible health hazards associated with exposure to diesel
engine exhaust.
- Fact Sheet: Diesel Exhaust and School Bus Idling (PDF) (2 pp, 442K, EPA420-F-03-005, April 2003) looks at school bus diesel exhaust and school children.
- Discussion Paper on diesel health assessment issues.
- Fact Sheet: Diesel Exhaust in the United States (PDF) (4 pp, 412K, EPA420-F-03-022, June 2003) with overview of diesel exhaust health effects and options for reducing pollution from diesel vehicles.
- Clean School Bus USA: Human Health provides general information on health effects of diesel exhaust and who is at risk.
- These pages contain cancer and non-cancer inhalation risk assessment
documents. Mobile sources account for the majority of nationwide
emissions of these hazardous air pollutants.
- Health Assessment of 1,3-Butadiene
- Carcinogenic Effects of Benzene
- Benzene (Noncarcinogenic) (PDF) (180 pp, 1.5MB, EPA635-R-02-001, October 2002)
- Acrolein (PDF) (106 pp, 329K, EPA635-R-03-003, May 2003)
- Agency for Toxic Substances and Disease Registry is an agency of the U.S. Department of Health and Human Services
that conducts assessments of health risks from a variety of substances.
- ATSDR Toxic Frequently Asked Questions is a series of summaries about hazardous substances.
- 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.
- Toxicology
and Environmental Health Information Program (TEHIP) is a comprehensive toxicology and environmental health web site
that includes access to resources produced by TEHIP and by other
government agencies and organizations.
Modeling and Analysis Tools
- NMIM National Mobile Inventory Model
- MOBILE6.2 Toxics Module for MOBILE6 Highway Vehicle Emission Factor Model
- Example Application of Modeling Toxics Air Pollutants in Urban Areas (PDF) (111 pp, 5.7MB, EPA454-R-02-003, June 2002). This report presents a case study of dispersion modeling in Houston for selected HAPs, using an approach which estimates highway vehicle toxic emissions along specific roadways.
- Support Center for Regulatory Air Models is EPA's source of information on air quality models for air toxics and criteria pollutants.
- Fate, Exposure, and Risk Analysis provides modeling tools for evaluation of health risks from air toxics and criteria pollutants. The HAPEM6 exposure model, which was used to support assessments in the final Mobile Source Air Toxics Rule, signed February 9, 2007, is available on this site.
- Consolidated Human Activities Database contains human activity data for use in inhalation exposure assessment.
- Human Exposure Database System is an integrated database system that contains chemical measurements, questionnaire responses, documents, and other information related to EPA research studies of the exposure of people to Environmental contaminants.
Technical Analysis Plan
- As part of its April 2001 mobile source air toxics rulemaking,
EPA identified four critical areas of research on mobile source
air toxics where there are data gaps, and committed to a technical
analysis plan to address these gaps. These areas were:
- emissions of air toxics from nonroad sources
- improved estimation of exposure in microenvironments
- characterizing mobile source "hot spots"
- improved understanding of effectiveness and costs of control strategies.
- Summary of Key Research Projects
- California
Air Resources Board School Bus Study
Regulations
Regulatory Documentation
Withdrawal of Direct Final Rule: Control of Hazardous Air Pollutants from Mobile Sources: Early Credit Technology Requirement Revision (published May 9, 2008)
Withdrawal of Direct Final Rule | PDF Version (1 page, 68K)
On March 12, 2008, EPA published a direct final rule (DFRM) and a parallel proposal to revise the February 26, 2007 mobile source air toxics rule's requirements that specify the benzene control technologies that qualify a refiner to generate early benzene credits. We stated in that direct final rule that if we received adverse comments by April 11, 2008, the direct final rule would not take effect and we would publish a timely withdrawal in the Federal Register. We received adverse comment on the rule and are withdrawing the direct final rule. We will address those comments in any subsequent final action, which will be based on the parallel proposed rule.
Direct Final Rule and Proposed Rule: Control of Hazardous Air Pollutants from Mobile Sources: Early Credit Technology Requirement Revision (published March 12, 2008)
EPA is taking direct final action to revise the February 26, 2007, mobile source air toxics rule's requirements that specify the benzene control technologies that qualify a refiner to generate early benzene credits.
- Direct Final Rule | PDF Version (5 pp, 75K)
- Proposed Rule | PDF Version (5 pp, 72K)
- Fact Sheet: Regulatory Announcement: Direct Final Rulemaking Revising Mobile Source Air Toxics Early Credit Technology Requirement | PDF Version (3 pp, 97K, EPA420-08-007, March 2008)
- Supporting Documentation: Information related to the development of this proposal can be found on the electronic docket at www.regulations.gov. NOTE: To access the docket, select "Advanced Search," then Docket Search, and type "EPA-HQ-OAR-2005-0036" as the Docket ID.
- Public Participation Opportunities: EPA welcomes your comments on this Proposed Rulemaking. Comments must be submitted by April 11, 2008. All comments should be identified by Docket ID "EPA-HQ-OAR-2005-0036" and submitted by one of the following methods: 1) Internet: www.regulations.gov 2) E-mail: A-and-R-Docket@epa.gov 3) Mail: Air and Radiation Docket and Information Center, U.S. Environmental Protection Agency, Mailcode 6102T, 1200 Pennsylvania Ave., NW, Washington, DC 20460 4) Hand Delivery: EPA Docket Center, 3340 EPA West Building, 1301 Constitution Ave., NW, Washington, DC.
Final Rule: Control of Hazardous Air Pollutants from Mobile Sources (published February 26, 2007)
EPA is finalizing new standards that would establish stringent new controls on gasoline, passenger vehicles, and gas cans to further reduce emissions of benzene and other mobile source air toxics.
- Final Rule:
- Pages 8427-8476 | PDF Version (50 pp, 1.13M)
- Pages 8477-8526 | PDF Version (50 pp, 769K)
- Pages 8527-8570 | PDF Version (44 pp, 763K)
- Fact Sheet: Control of Hazardous Air Pollutants from Mobile Sources | PDF Version (5 pp, 143K, EPA420-F-07-017, February 2007)
- The entire Summary and Analysis of Comments (PDF) (204 pp, 1.2MB, EPA420-R-07-003, February 2007) Instead of downloading the entire document, you can access the individual chapters of the Summary and Analysis of Comments.
- The entire Regulatory Impact Analysis (PDF) (807 pp, 15.6MB, 420-R-07-002, February 2007) Instead of downloading the entire document, you can access the individual chapters of the Regulatory Impact Analysis.
- Technical Support Documents:
- Cold Temperature Effects on Vehicle HC Emissions (PDF) (12 pp, 221K, EPA420-D-06-001, February 2006)
- Estimating Emissions Associated with Portable Fuel Containers (PFCs) (PDF) (30 pp, 628K, EPA420-R-07-001, February 2007)
- Technical Support Document for the Final Mobile Source Air Toxics Rule: Ozone Modeling (PDF) (51 pp, 1.2MB, EPA454-R-07-003, February 2007)
- National Scale Modeling of Air Toxics for the Mobile Source Air Toxics Rule; Technical Support Document (PDF) (215 pp, 10.3MB, EPA454-R-07-002, February 2007)
- Final Report of the Small Business Advocacy Review Panel:
Executive Summary (PDF) (12 pp, 1.0MB, EPA420-S-05-901, November 8, 2005)
Final Panel Report (PDF) (107 pp, 693K, EPA420-R-05-901, November 8, 2005)
NOTE: Since some files are so large, it may take a long time to download the files even with a high-speed connection. Large downloads work best when you are not attempting to run other applications on your computer and when traffic on your network is low.
Proposed Rule: Control of Hazardous Air Pollutants from Mobile Sources (published March 29, 2006)
- Fact Sheet: Control of Hazardous Air Pollutants from Mobile Sources | PDF Version (5 pp, 324K, EPA420-F-06-021, February 2006)
- Notice: Preamble
and Regulations (PDF) (161 pp, 1.5MB, published March
29, 2006)
- pages 15803-15852 | PDF Version (50 pp, 1MB)
- pages 15853-15902 | PDF Version (50 pp, 561K)
- pages 15903-15952 | PDF Version (50 pp, 557K)
- pages 15953-15963 | PDF Version (11 pp, 165K)
- The entire Regulatory Impact Analysis (Zip file of PDF) (10MB, EPA420-D-06-004, February 2006) Instead of downloading the entire document, you can access individual chapters of the Regulatory Impact Analysis.
- Technical Support Documents:
- Cold Temperature Effects on Vehicle HC Emissions (PDF) (12 pp, 221K, EPA420-D-06-001, February 2006)
- Estimating Emissions Associated with Portable Fuel Containers (PFCs) (PDF) (30 pp, 499K, EPA420-D-06-003, February 2006)
- Technical Support Document for the Proposed Mobile Source Air Toxics Rule: Ozone Modeling (PDF) (49 pp, 1.6MB, February 2006)
- National Scale Modeling of Air Toxics for the Mobile Source Air Toxics Rule; Technical Support Document (PDF) (224 pp, 9.4MB, EPA454-R-06-002, January 2006)
- Final Report of the Small Business Advocacy Review Panel:
Executive Summary (PDF) (12 pp, 1.0MB, EPA420-S-05-901, November 8, 2005)
Final Panel Report (PDF) (107 pp, 693K, EPA420-R-05-901, November 8, 2005)
- Notice: Revisions to the List of Product Categories Scheduled for Regulation Under Section (183)(e) of the Clean Air Act (CAA) | PDF Version (5 pp, 110K)
NOTE: Since the file is so large, it may take a long time to download even with a high-speed connection. Large downloads work best when you are not attempting to run other applications on your computer and when traffic on your network is low. (Free zip software is available at http://www.download.com
Final Rule: Control of Emissions of Hazardous Air Pollutants from Mobile Sources: Default Baseline Revision (published October 6, 2005)
- Notice: Control of Emissions of Hazardous Air Pollutants From Mobile Sources: Default Baseline Revision (PDF) (6 pp, 74K)
- Fact Sheet: Final Rulemaking to Revise MSAT Default Baseline Values | PDF Version (2 pp, 44K, EPA420-F-05-034, September 2005)
Proposed Rule: Control Emissions of Hazardous Air Pollutants from Mobile Sources: Default Baseline Revision (January 4, 2005)
- Press Advisory: EPA Proposes Adjustments in Air Toxics Baseline for Certain Gasoline Refiners and Importers. (December 22, 2004)
- Notice: Preamble and Regulations | PDF Version (8 pp, 132K)
- Fact Sheet: Notice of Proposed Rulemaking to Revise MSAT Default Baseline Values | PDF Version (3 pp, 26K, EPA420-F-04-014, December 2004)
- Mobile Source Air Toxics Rule Questions and Answers (PDF) (8 pp, 28K, EPA420-F-01-031, October 12, 2001)
- Notice: Preamble and Regulations | PDF Version (45 pp, 290K)
- Press Release: New Toxic Emission Standards Set for Gasoline (December 21, 2000)
- Fact Sheet: Control of Emissions of Hazardous Air Pollutants from Mobile Sources (PDF) (3 pp, 40K, EPA420-F-00-055, December 2000)
- Technical Support Document: Control of Emissions of Hazardous Air Pollutants from Motor Vehicles and Motor Vehicle Fuels (PDF) (195 pp, 415K, EPA420-R-00-023, December 2000)
- Response to Comments: Control of Emissions of Hazardous Air Pollutants from Mobile Sources (PDF) (140 pp, 415K, EPA420-R-00-024, December 2000)
- Notice: Preamble and Regulations | PDF Version (49 pp, 412K)
- Draft Technical Support Document: Control of Emissions of Hazardous Air Pollutants from Motor Vehicles and Motor Vehicle Fuels (PDF) (162 pp, 502K, PA420-D-00-003, July 2000)
- Fact Sheet: Proposed Rule to Control Emissions of Hazardous Air Pollutants from Mobile Sources (PDF)(4 pp, 13K, EPA420-F-00-025, July 2000)
Implementation & Support
MSAT2 Questions and Answers (PDF) (6 pp, 66K, EPA420-F-07-053)
Guidance to Parties Submitting Mobile Source Air Toxics Baseline Applications
- MSAT2 Benzene Baseline Template (Excel) (28K): The Final Rule for the Control of Hazardous Air Pollutants From Mobile Sources (72 FR 8428, February 26, 2007), also known as "MSAT2" allows a refiner to generate early benzene credits if the refiner meets certain requirements, including applying for a benzene baseline (and provided the application is ultimately approved by EPA). This template may be used to submit some of the benzene baseline application information required by the regulations. Questions may be directed to John Weihrauch, (202) 343-9477, or weihrauch.john@epa.gov.
- Guidance to Parties Submitting Mobile Source Air Toxics Baseline Applications (PDF) (5 pp, 11K, EPA420-F-01-017, June 2001)
- Spreadsheet templates Excel (14K) or WK4 (5K)
Reducing Risk in Communities
- Air Toxics Community Assessment and Risk Reductions Database has been compiled to provide a resource of planned, completed, and ongoing community level air toxics assessments around the country.
- Clean School Bus USA is EPA's national partnership to minimize pollution from school buses. Leaders from corporate America, children's health, environmental and governmental organizations gather to design a plan to reduce children's exposure to diesel exhaust by eliminating unnecessary school bus idling, installing effective emission control systems on newer buses and replacing the oldest buses in the fleet with newer ones. For more information contact the Clean School Bus USA Team at (734) 214-4780 or email: CleanSchoolBusUSA@epa.gov.
- EPA's Voluntary Diesel Retrofit Program works to reduce pollution, including air toxics, resulting from existing diesel vehicles and equipment by encouraging fleet owners to install pollution-reducing devices on the vehicles and to use cleaner-burning diesel fuel.
- Best Workplaces for Commuters is a voluntary program, now administered by the Center for Urban Transportation Research (CUTER), offering innovative solutions to commuting challenges faced by employers and employees. Reducing vehicle miles traveled is an effective way to reduce air toxics risk in communities.
- State and Local Transportation Resources Grants and Funding provides links to federal funding sources available to state and local agencies for projects relating to transportation and air quality. Funding sources both within and outside EPA are included.
- Green Communities is designed to help communities access the tools and information that would help them become more sustainable, green communities.
- Tools for Schools program is a comprehensive resource to maintain healthy air in school buildings by identifying, correcting and preventing indoor air quality problems.
- Cleveland
Clean Air Century Campaign Update (March 2005): EPA selected Cleveland to host the first demonstration of a new
approach to air toxics control that will serve as a model for
communities nationwide. The pilot will address pollutants from
many sources, both indoors and outdoors, and will put into place
a risk reduction program to combat serious urban toxic air pollutants
in the city. The project has three goals: reduce risks from air
toxics in Cleveland within a year, ensure the project is sustainable,
and ensure the approach can be replaced by other communities.
- Portland,
Oregon Air Toxics Assessment: EPA is helping to support this refined local scale assessment
led by the Oregon Department of Environmental Quality.
- Philadelphia Toxic Air Pollutants Risk Reduction Project EPA and Philadelphia Air Management Services are conducting a joint project called the "Philadelphia Toxic Air Pollutants Risk Reduction Project" to help reduce the threat to their health which Philadelphia's residents face from exposure to air toxics.
- Example Application of Modeling Toxic Air Pollutants in Urban Areas (PDF, 111 pages, 5.6M) (EPA454-R-02-003, June 2002). This report presents a case study of dispersion modeling in Houston for selected Hazardous Air Pollutants (HAPs) using an approach which estimates highway vehicle toxic emissions along specific roadways.
- West Oakland
Pilot Project: This resident-led initiative resulted in a series of solutions
for reducing exposure to diesel pollution in the heavily impacted
West Oakland community.
For further information, contact EPA's Assessment and Standards Division at asdinfo@epa.gov or 734-214-4636.