Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards

Federal RegisterApr 28, 2014

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 79, 80, 85, 86, 600, 1036, 1037, 1039, 1042, 1048, 1054, 1065, and 1066

[EPA-HQ-OAR-2011-0135; FRL 9906-86-OAR]

RIN 2060-AQ86

Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Final rule.

SUMMARY:

This action establishes more stringent vehicle emissions standards and will reduce the sulfur content of gasoline beginning in 2017, as part of a systems approach to addressing the impacts of motor vehicles and fuels on air quality and public health. The gasoline sulfur standard will make emission control systems more effective for both existing and new vehicles, and will enable more stringent vehicle emissions standards. The vehicle standards will reduce both tailpipe and evaporative emissions from passenger cars, light-duty trucks, medium-duty passenger vehicles, and some heavy-duty vehicles. This will result in significant reductions in pollutants such as ozone, particulate matter, and air toxics across the country and help state and local agencies in their efforts to attain and maintain health-based National Ambient Air Quality Standards. Motor vehicles are an important source of exposure to air pollution both regionally and near roads. These vehicle standards are intended to harmonize with California's Low Emission Vehicle program, thus creating a federal vehicle emissions program that will allow automakers to sell the same vehicles in all 50 states. The vehicle standards will be implemented over the same timeframe as the greenhouse gas/fuel efficiency standards for light-duty vehicles (promulgated by EPA and the National Highway Safety Administration in 2012), as part of a comprehensive approach toward regulating emissions from motor vehicles.

DATES:

This final rule is effective on June 27, 2014. The incorporation by reference of certain publications listed in this regulation is approved by the Director of the Federal Register as of June 27, 2014.

ADDRESSES:

EPA has established a docket for this action under Docket ID No. EPA-HQ-OAR-2011-0135. All documents in the docket are listed on the

www.regulations.gov

Web site. Although listed in the index, some information is not publicly available, e.g., CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the Internet and will be publicly available only in hard copy form. Publicly available docket materials are available either electronically in

www.regulations.gov

or in hard copy at the Air and Radiation Docket and Information Center, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave. NW., Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is (202) 566-1744, and the telephone number for the Air Docket is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT:

JoNell Iffland, Office of Transportation and Air Quality, Assessment and Standards Division (ASD), Environmental Protection Agency, 2000 Traverwood Drive, Ann Arbor MI 48105; Telephone number: (734) 214-4454; Fax number: (734) 214-4816; Email address:

iffland.jonell@epa.gov

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this action apply to me?

Entities potentially affected by this rule include gasoline refiners and importers, ethanol producers, ethanol denaturant producers, butane and pentane producers, gasoline additive manufacturers, transmix processors, terminals and fuel distributors, light-duty vehicle manufacturers, independent commercial importers, alternative fuel converters, and manufacturers and converters of vehicles between 8,500 and 14,000 lbs gross vehicle weight rating (GVWR).

Potentially regulated categories include:

Category

NAICS

Code

SIC

Code

Examples of potentially affected entities

Industry

324110

2911

Petroleum refineries (including importers).

Industry

325110

2869

Butane and pentane manufacturers.

Industry

325193

2869

Ethyl alcohol manufacturing.

Industry

324110, 211112

2911, 1321

Ethanol denaturant manufacturers.

Industry

211112

1321

Natural gas liquids extraction and fractionation.

Industry

325199

2869

Other basic organic chemical manufacturing.

Industry

486910

4613

Natural gas liquids pipelines, refined petroleum products pipelines.

Industry

424690

5169

Chemical and allied products merchant wholesalers.

Industry

325199

2869

Manufacturers of gasoline additives.

Industry

424710

5171

Petroleum bulk stations and terminals.

Industry

493190

4226

Other warehousing and storage-bulk petroleum storage.

Industry

336111, 336112

3711

Light-duty vehicle and light-duty truck manufacturers.

Industry

811111, 811112, 811198

7538, 7533, 7534

Independent commercial importers.

Industry

335312, 336312, 336322, 336399, 811198

3621, 3714, 3519, 3599, 7534

Alternative fuel converters.

Industry

333618, 336120, 336211, 336312

3699, 3711, 3713, 3714

On-highway heavy-duty engine & vehicle (>8,500 lbs GVWR) manufacturers.

North American Industry Classification System (NAICS).

Standard Industrial Classification (SIC).

This table is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely to be regulated by this action. This table lists the types of entities that EPA is now aware could potentially be regulated by this action. Other types of entities not listed in the table could also be regulated. To determine whether your activities are regulated by this action, you should carefully examine the applicability criteria in 40 CFR parts 79,

80, 85, 86, 600, 1036, 1065, and 1066 and the referenced regulations. If you have any questions regarding the applicability of this action to a particular entity, consult the person listed in the preceding

FOR FURTHER INFORMATION CONTACT

section.

B. Did EPA conduct a peer review before issuing this action?

This regulatory action was supported by influential scientific information. Therefore, EPA conducted peer reviews in accordance with OMB's Final Information Quality Bulletin for Peer Review. EPA conducted several peer reviews in connection with data supporting the Tier 3 program, including new research on the effects of fuel properties changes (including sulfur effects) on exhaust and evaporative emissions of Tier 2 vehicles. The refinery-by-refinery cost model was also peer reviewed. The peer review reports are located in the docket for today's action, as well as the agency's response to the peer review comments.

Table of Contents

I. Executive Summary and Program Overview

A. Introduction

B. Overview of the Tier 3 Program

1. Major Public Comments and Key Changes From the Proposal

2. Key Components of the Tier 3 Program

C. What will the impacts of the standards be?

II. Why is EPA taking this action?

A. Basis for Action Under the Clean Air Act

1. Clean Air Act Section 202

2. Clean Air Act Section 211

B. Overview of Public Health Impacts of Motor Vehicles and Fuels

1. Ozone

2. Particulate Matter

3. Oxides of Nitrogen and Sulfur

4. Carbon Monoxide

5. Mobile Source Air Toxics

6. Near-Roadway Pollution

7. Environmental Impacts of Motor Vehicles and Fuels

III. How would this rule reduce emissions and air pollution?

A. Effects of the Vehicle and Fuel Changes on Mobile Source Emissions

1. How do vehicles produce the emissions addressed in this action?

2. How will the changes to gasoline sulfur content affect vehicle emissions?

B. How will emissions be reduced?

1. NO

2. VOC

3. CO

4. Direct PM

2.5

5. Air Toxics

6. SO

7. Greenhouse Gases

C. How will air pollution be reduced?

1. Ozone

2. Particulate Matter

3. Nitrogen Dioxide

4. Air Toxics

5. Visibility

6. Nitrogen and Sulfur Deposition

7. Environmental Justice

IV. Vehicle Emissions Program

A. Tier 3 Tailpipe Emission Standards for Light-Duty Vehicles, Light-Duty Trucks, and Medium-Duty Passenger Vehicles

1. How the Tier 3 Program is harmonized with the California LEV III Program

2. Summary of the Tier 3 FTP and SFTP Tailpipe Standards

3. FTP Standards

4. SFTP Standards

5. Feasibility of the NMOG+NO

and PM Standards

6. Impact of Gasoline Sulfur Control on the Effectiveness of the Vehicle Emission Standards

7. Other Provisions

B. Tailpipe Emissions Standards for Heavy-Duty Vehicles

1. Overview and Scope of Vehicles Regulated

2. HDV Exhaust Emissions Standards

3. Supplemental FTP Standards for HDVs

4. HDV Emissions Averaging, Banking, and Trading

5. Feasibility of HDV Standards

6. Other HDV Provisions

C. Evaporative Emissions Standards

1. Tier 3 Evaporative Emission Standards

2. Program Structure and Implementation Flexibilities

3. Technological Feasibility

4. Heavy-Duty Gasoline Vehicle (HDGV) Requirements

5. Evaporative Emission Requirements for FFVs

6. Test Procedures and Certification Test Fuel

D. Improvements to In-Use Performance of Fuel Vapor Control Systems

1. Reasons for Adding a Leak Test Standard

2. Nature, Scope and Timing of Leak Standard

3. Leak Standard Test Procedure

4. Certification and Compliance

a. In-Use Verification Program (IUVP) Requirements for the Leak Standard

E. Onboard Diagnostic System Requirements

1. Onboard Diagnostic (OBD) System Regulation Changes—Timing

2. Revisions to EPA OBD Regulatory Requirements

3. Provisions for Emergency Vehicles

4. Future Considerations

F. Emissions Test Fuel

1. Gasoline Emissions Test Fuel: Ethanol Content and Volatility

2. Other Gasoline Emissions Test Fuel Specifications

3. Flexible Fuel Vehicle Exhaust Emissions Test Fuel

4. Implementation Schedule

5. Implications of Emission Test Fuel Changes on CAFE Standards, GHG Standards, and Fuel Economy Labels

6. Consideration of Test Fuel for Nonroad Engines and Highway Motorcycles

7. CNG and LPG Emissions Test Fuel Specifications

G. Small Business Provisions

1. Lead Time and Relaxed Interim Standards

2. Assigned Deterioration Factors

3. Reduced Testing Burden and OBD Requirements

4. Hardship Relief

5. Eligibility for the Flexibilities

H. Compliance Provisions

1. Exhaust Emission Test Procedures

2. Reduced Test Burden

3. Miscellaneous Provisions

4. Manufacturer In-Use Verification Program (IUVP) Requirements

V. Fuel Program

A. Overview

1. Background

2. Summary of Final Tier 3 Fuel Program Standards

B. Annual Average Sulfur Standard

C. Per-Gallon Sulfur Caps

1. Standards

2. Requirements for Gasoline Additives

D. Averaging, Banking, and Trading Program

1. How will the ABT Program assist with compliance?

2. ABT Modeling

3. Eligibility

4. Credit Generation and Use

5. Credit Trading Provisions

6. ABT Provisions for Small Refiners and Small Volume Refineries

7. Deficit Carryforward

E. Additional Program Flexibilities

1. Regulatory Flexibility Provisions

2. Provisions for Refiners Facing Hardship Situations

F. Compliance Provisions

1. Registration, Reporting, and Recordkeeping Requirements

2. Sampling and Testing Requirements

3. Small Refiner Compliance

4. Small Volume Refinery Compliance

5. Attest Engagements, Violations, and Penalties

6. Special Fuel Provisions and Exemptions

G. Standards for Oxygenates (Including Denatured Fuel Ethanol) and Certified Ethanol Denaturants

H. Standards for Fuel Used in Flexible Fueled Vehicles

I. Sulfur Standards for Purity Butane and Purity Pentane Streams Blended into Gasoline

J. Standards for CNG and LPG

K. Refinery Air Permitting Interactions

1. Proposal

2. Updated Assessment of Tier 3 Refinery Changes and Permitting Implications

3. Comments and Responses

L. Refinery Feasibility

1. Comments Received

2. Is it feasible for refiners to comply with a 10 ppm average sulfur standard?

3. Can refiners meet the January 1, 2017 start date?

M. Statutory Authority for Tier 3 Fuel Controls

1. Section 211(c)(1)(A)

2. Section 211(c)(1)(B)

3. Section 211(c)(2)(B)

4. Section 211(c)(2)(C)

VI. Technical Amendments and Regulatory Streamlining

A. Fuel Program Amendments

1. Fuels Program Regulatory Streamlining

2. Performance-Based Measurement Systems (PBMS)

3. Downstream Pentane Blending

4. Acceptance of Top Tier Deposit Control Test Data

5. Potential Broader Regulatory Streamlining Through Program Restructuring

B. Engine, Vehicle and Equipment Programs Amendments

1. Fuel Economy Labeling

2. Removing Obsolete Regulatory Text

3. Motorcycle Driving Schedules

4. Updating Reference Procedures

VII. What are the cost impacts of the rule?

A. Estimated Costs of the Vehicle Standards

1. What changes have been made to vehicle program costs since proposal?

2. Summary of Vehicle Program Costs

B. Estimated Costs of the Fuel Program

1. Overview

2. Methodology

3. Fuel Program Costs

4. Other Cost Estimates

C. Summary of Program Costs

VIII. What are the estimated benefits of the rule?

A. Overview

B. Quantified Human Health Impacts

C. Monetized Benefits

D. What are the limitations of the benefits analysis?

E. Illustrative Analysis of Estimated Monetized Impacts Associated With the Rule in 2018

IX. Alternatives Analysis

A. Vehicle Emission Standards

1. Shorter NMOG+NO

Standard Phase-in

2. NMOG+NO

Standards Phase-in and Early Tier 3 Credits

3. NMOG+NO

Standards

4. PM Standards

5. Higher Ethanol Content of Emissions Test Fuel

B. Fuel Sulfur Standards

1. Annual Average Sulfur Standard

2. Refinery Gate Sulfur Cap

C. Program Start Date

X. Economic Impact Analysis

A. Introduction

B. Vehicle Sales Impacts

C. Impacts on Petroleum Refinery Sector Production

D. Employment Impacts

1. Employment Impacts in the Auto Sector

2. Refinery Employment Impacts

XI. Public Participation

XII. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive Order 13563: Improving Regulation and Regulatory Review

B. Paperwork Reduction Act

C. Regulatory Flexibility Act

1. Overview

2. Background

3. Reason for Today's Rule

4. Legal Basis for Agency Action

5. Summary of Potentially Affected Small Entities

6. Reporting, Recordkeeping, and Compliance

7. Related Federal Rules

8. Steps Taken To Minimize the Economic Impact on Small Entities

D. Unfunded Mandates Reform Act

E. Executive Order 13132: Federalism

F. Executive Order 13175: Consultation and Coordination With Indian Tribal Governments

G. Executive Order 13045: Protection of Children From Environmental Health Risks and Safety Risks

H. Executive Order 13211: Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use

I. National Technology Transfer and Advancement Act

J. Executive Order 12898: Federal Actions To Address Environmental Justice in Minority Populations and Low-Income Populations

K. Congressional Review Act

XIII. Statutory Provisions and Legal Authority

I. Executive Summary and Program Overview

A. Introduction

In this action, EPA is finalizing a major program designed to reduce air pollution from passenger cars and trucks. This program includes new standards for both vehicle emissions and the sulfur content of gasoline, considering the vehicle and its fuel as an integrated system. We refer to this program as the “Tier 3” vehicle and fuel standards.

This rule is part of a comprehensive approach to address the impacts of motor vehicles on air quality and public health. Over 149 million Americans are currently experiencing unhealthy levels of air pollution, which are linked with respiratory and cardiovascular problems and other adverse health impacts that lead to increased medication use, hospital admissions, emergency department visits, and premature mortality.

Motor vehicles are a particularly important source of exposure to air pollution, especially in urban areas. By 2018, we project that in many areas that are not attaining health-based ambient air quality standards (i.e., “nonattainment areas”), passenger cars and light trucks will contribute 10-25 percent of total nitrogen oxides (NO

) emissions, 15-30 percent of total volatile organic compound (VOC) emissions, and 5-10 percent of total direct particulate matter (PM

2.5

) emissions.

These compounds form ozone, PM, and other air pollutants, whose health and environmental effects are described in more detail in Section II. Cars and light trucks also continue to be a significant contributor to air pollution directly near roads, with gasoline vehicles accounting for more than 50 percent of near-road concentrations of some criteria and toxic pollutants.

More than 50 million people live, work, or go to school in close proximity to high-traffic roadways, and the average American spends more than one hour traveling along roads each day.

4 5

Over 80 percent of daily trips use personal vehicles.

The 149 million represents people living in O

, PM

2.5

, PM

, and SO

nonattainment areas. Data come from Summary Nonattainment Area Population Exposure Report, current as of December 5, 2013 at:

http://www.epa.gov/oar/oaqps/greenbk/popexp.html

and contained in Docket EPA-HQ-OAR-2011-0135.

Mobile source contributions derived from inventories developed for this rule. For more information on these inventories see the Emissions Inventory Technical Support Document (TSD) for the final Tier 3 Rule, Docket ID No. EPA-HQ-OAR-2011-0135.

For example, see Fujita, E.M; Campbell, D.E.; Zielinska, B.; Arnott, W.P.; Chow, J.C. (2011) Concentrations of Air Toxics in Motor Vehicle-Dominated Environments. Health Effects Institute Research Report 156. Available at

http://www.healtheffects.org

U.S. Census Bureau (2011). Current Housing Reports, Series H150/09, American Housing Survey for the United States: 2009. U.S. Government Printing Office, Washington, DC. Available at

http://www.census.gov/hhes/www/housing/ahs/ahs09/ahs09.html

. (Note that this survey includes estimates of homes within 300 feet of highways with four or more lanes, railroads, and airports.)

Drago, R. (2011). Secondary activities in the 2006 American Time Use Survey. U.S. Bureau of Labor Statistics Working Paper 446. Available at

http://www.bls.gov

Santos, A.; McGuckin, N, Yukiko Nakamoto, H.; Gray, D.; Liss, S. (2011) Summary of Travel Trends: 2009 National Household Travel Survey. Federal Highway Administration report no FHWA-PL-11-022. Available at

http://nhts.ornl.gov/publications.shtml

The standards set forth in this rule will significantly reduce levels of multiple air pollutants (such as ambient levels of ozone, PM, nitrogen dioxide (NO

), and mobile source air toxics (MSATs)) across the country, with immediate benefits from the gasoline sulfur control standards starting in 2017. These reductions will help state and local agencies in their effort to attain and maintain health-based National Ambient Air Quality Standards (NAAQS). Few other national strategies exist that will deliver the same magnitude of multi-pollutant reductions and associated public health protection that is projected to result from the Tier 3 standards. Without this action to reduce nationwide motor vehicle emissions, areas would have to adopt other, less cost-effective measures to reduce emissions from other sources under their state or local authority. In the absence of additional controls, certain areas would continue to have ambient ozone concentrations exceeding the NAAQS in the future. See Section III.C for more details.

The Clean Air Act authorizes EPA to establish emissions standards for motor vehicles to address air pollution that may reasonably be anticipated to endanger public health or welfare

(section 202). EPA also has authority to establish fuel controls to address such air pollution (section 211). These statutory authorities are described in Section II.A.

The vehicle and gasoline sulfur standards we are finalizing represent a “systems approach” to reducing vehicle exhaust and evaporative emissions by addressing the vehicle and fuel as a system. The systems approach enables emission reductions that are both technologically feasible and cost-effective beyond what would be possible looking at vehicle and fuel standards in isolation. We first applied such an approach with our Tier 2 vehicle/gasoline sulfur standards (finalized in 2000).

We believe that a similar approach for the Tier 3 standards is a cost-effective way to achieve substantial additional emissions reductions.

65 FR 6698 (February 10, 2000).

The Tier 3 standards include new light- and heavy-duty vehicle emission standards for exhaust emissions of VOC (specifically, non-methane organic gases, or NMOG), NO

, and PM, as well as new evaporative emissions standards. The fully phased-in standards for light-duty vehicle, light-duty truck, and medium-duty passenger vehicle tailpipe emissions are an 80 percent reduction in fleet average NMOG+NO

compared to current standards, and a 70 percent reduction in per-vehicle PM standards. The fully phased-in Tier 3 heavy-duty vehicle tailpipe emissions standards for NMOG+NO

and PM are on the order of 60 percent lower than current standards. Finally, the fully phased-in evaporative emissions standards represent a 50 percent reduction from current standards.

The vehicle emission standards, combined with the reduction of gasoline sulfur content from the current 30 parts per million (ppm) average down to a 10 ppm average, will result in dramatic emissions reductions for NO

, VOC, direct PM

2.5

, carbon monoxide (CO) and air toxics. For example, in 2030, when Tier 3 vehicles will make up the majority of the fleet as well as vehicle miles traveled, NO

and VOC emissions from on-highway vehicles will be reduced by about 21 percent, and CO emissions will be reduced by about 24 percent. National emissions of many air toxics from on-highway vehicles will also be reduced by 10 to nearly 30 percent. Reductions will continue beyond 2030 as more of the fleet is composed of vehicles meeting the fully phased-in Tier 3 standards. For example, the Tier 3 program will reduce on-highway emissions of NO

and VOC nearly 31 percent by 2050, when vehicles meeting the fully phased-in Tier 3 standards will comprise almost the entire fleet.

Gasoline vehicles depend to a great degree on catalytic converters to reduce levels of pollutants in their exhaust, including NMOG and NO

, as well as PM (specifically, the volatile hydrocarbon fraction), CO, and most air toxics. The catalytic converters become significantly less efficient when exposed to sulfur. The Tier 2 rulemaking required refiners to take steps to reduce sulfur levels in gasoline by approximately 90 percent, to an average of 30 ppm. As discussed in Section IV.A.6, subsequent research provides a compelling case that even this level of sulfur not only degrades the emission performance of vehicles on the road today, but also inhibits necessary further reductions in vehicle emissions performance to reach the Tier 3 standards. Thus, the 10 ppm average sulfur standard for Tier 3 is significant in two ways: it enables vehicles designed to the Tier 3 tailpipe exhaust standards to meet these standards in-use for the duration of their useful life, and it facilitates immediate emission reductions from all the vehicles on the road at the time the fuel sulfur controls are implemented. EPA is not the first regulatory agency to recognize the need for lower-sulfur gasoline. Agencies in Europe and Japan have already imposed gasoline sulfur caps of 10 ppm, and the State of California is already averaging 10 ppm sulfur with a per gallon cap of 20 ppm. Other states are preempted by the Clean Air Act from adopting new fuel programs to meet air quality objectives. Consequently, they could not receive the air quality benefits of lower sulfur gasoline without federal action.

This action is one aspect of a comprehensive national program regulating emissions from motor vehicles. EPA's final rule for reducing greenhouse gas (GHG) emissions from light-duty (LD) vehicles starting with model year (MY) 2017 (referred to here as the “2017 LD GHG” standards) is another aspect of this comprehensive program.

The Tier 3 program addresses interactions with the 2017 LD GHG rule in a manner that aligns implementation of the two actions, to achieve significant criteria pollutant and GHG emissions reductions while providing regulatory certainty and compliance efficiency. As vehicle manufacturers introduce new vehicle platforms for compliance with the GHG standards, they will be able to design them for compliance with the Tier 3 standards at the same time. The Tier 3 standards are also closely coordinated with California's Low Emission Vehicle (LEV) III program to create a vehicle emissions program that will allow automakers to sell the same vehicles in all 50 states. (In December 2012 EPA approved a waiver of Clean Air Act preemption for the California Air Resources Board's (CARB's) LEV III program with compliance beginning in 2015. Twelve states adopted the LEV III program under Section 177 of the Clean Air Act.

) We have worked closely with individual vehicle manufacturers and their trade associations, who have emphasized the importance of a harmonized national program. Together, the Tier 3, 2017 LD GHG, and LEV III standards will provide significant reductions in GHGs, criteria pollutants and air toxics from motor vehicles while streamlining programs and enabling manufacturers to design a single vehicle for nationwide sales, thus reducing their costs of compliance. In this way, the Tier 3 program responds to the May 21, 2010 Presidential Memorandum that requested that EPA develop a comprehensive approach toward regulating motor vehicles, including consideration of non-GHG emissions standards.

EPA's GHG standards are part of a joint National Program with the National Highway Traffic Safety Administration, which also set coordinated standards for Corporate Average Fuel Economy (CAFE). 77 FR 62623 (October 15, 2012).

These states include Connecticut, Delaware, Maryland, Maine, Massachusetts, New Jersey, New York, Oregon, Pennsylvania, Rhode Island, Washington, and Vermont.

The Presidential Memorandum is found at:

http://www.whitehouse.gov/the-press-office/presidential-memorandum-regarding-fuel-efficiency-standards

As part of the systems approach to this program, we have considered the types of fuels on which vehicles will be operating in the future. In particular, the renewable fuels mandate that was revised by the Energy Independence and Security Act (EISA) and is being implemented through the Renewable Fuel Standards program (RFS2)

is resulting in the use of significant amounts of ethanol-blended gasoline. We are updating the specifications of the emissions test fuel with which vehicles demonstrate compliance with emissions standards, in order to better reflect the ethanol content and other properties of gasoline that is in use today and is expected in future years.

75 FR 14670 (March 26, 2010).

Section I provides an overview of the vehicle and fuel standards we are finalizing as well as the impacts of the standards. The public health issues and statutory requirements that have prompted this action are described in Section II, and our discussion of how

the Tier 3 standards will reduce emissions and air pollution is presented in Section III. Details of the standards and how they will be implemented can be found in Sections IV through VI. Sections VII through X contain our discussion of the standards' technological feasibility and costs, benefits, and economic impacts. Sections XI through XIII address public participation, statutory and executive orders, and statutory provisions and legal authority under the Clean Air Act covered in this rulemaking.

This final rule is based on extensive public input received in response to EPA's Tier 3 proposal. The proposal was signed and posted on the EPA Web site on March 29, 2013, and published in the

Federal Register

on May 21, 2013. EPA held two public hearings in Philadelphia and Chicago in April 2013. In response to stakeholder requests, EPA extended the public comment period to July 1, 2013. We received more than 200,000 public comments. A broad range of stakeholders provided comments, including state and local governments, auto manufacturers, emissions control suppliers, refiners, fuel distributors and others in the petroleum industry, renewable fuels providers, environmental organizations, consumer groups, labor groups, private citizens, and others. Some of the issues raised in comments included lead time and the program's start date, the vehicle manufacturers' support for a 50-state program harmonized with California, the need for and degree of gasoline sulfur control (including the level of the sulfur cap), the ethanol content of vehicle certification test fuel, and various details on the flexibilities and other program design features of both the vehicle and fuels standards.

B. Overview of the Tier 3 Program

In the 14 years since EPA established the Tier 2 Vehicle Program, manufacturers of light-duty vehicles and automotive technology suppliers have continued to develop a wide range of improved technologies capable of reducing vehicle emissions. The California LEV II program has been instrumental in the continuous technology improvements by requiring year after year reductions in fleet average hydrocarbon levels, in addition to requiring the introduction of advanced exhaust and evaporative emission controls in partial zero emission vehicles (PZEVs). This technological progress has made it possible for manufacturers to achieve emission reductions well beyond the requirements of the Tier 2 program if gasoline sulfur levels are lowered further.

As a result, in conjunction with lower gasoline sulfur standards, we are establishing new Tier 3 standards for exhaust emissions of NMOG, NO

, and PM, as well as for evaporative hydrocarbon emissions. These vehicle emissions standards will phase in beginning with MY 2017. The structure of the Tier 3 standards is very similar to that of the existing Tier 2 program. As with the Tier 2 program, the standards will apply to all light-duty vehicles (LDVs, or passenger cars), light-duty trucks (LDT1s, LDT2s, LDT3s, and LDT4s) and Medium-Duty Passenger Vehicles (MDPVs). We also are establishing separate but closely related standards for heavy-duty vehicles up to 14,000 lbs Gross Vehicle Weight Rating (GVWR).

We have concluded that the vehicle emissions standards, in conjunction with the reductions in fuel sulfur also required by this action, are feasible across the fleet in the timeframe provided.

These heavy-duty vehicles were not included in the Tier 2 program but were subject to standards in a subsequent rule covering the heavy-duty sector (66 FR 5002, January 18, 2001).

Auto manufacturers have stressed the importance of being able to design, produce, and sell a single fleet of vehicles in all 50 states that complies with both the Tier 3 and California LEV III programs, as well as the greenhouse gas (GHG)/Corporate Average Fuel Economy (CAFE) programs in the same timeframe. To that end, we worked closely with the California Air Resources Board and vehicle manufacturers to align the two programs as closely as possible. This consistency among the federal and California programs means that manufacturers do not need to design unique versions of vehicles with different emission control hardware and calibrations for different geographic areas. This allows manufacturers to avoid the additional costs of parallel design, development, calibration, and manufacturing. We also have designed the Tier 3 program to be implemented in the same timeframe as the GHG emissions and fuel economy standards for model years 2017-2025. We expect that in response to these programs, manufacturers will be developing entirely new powertrains for most of their vehicles. Because the Tier 3 standards will phase in over the same timeframe, manufacturers are in a better position to simultaneously respond to all of these requirements.

Overall, the final Tier 3 program is very similar to the program we proposed. As discussed below and throughout this preamble, the program phases in over several years—with the primary vehicle emission standards starting in Model Year (MY) 2017 (2018 for heavier vehicles) and the gasoline sulfur control provisions beginning in 2017.

As discussed above, we received a large number and wide range of comments on the proposed rule. Several comments raise particularly significant issues concerning some fundamental components of the Tier 3 program, including when the vehicle-related and fuel-related requirements begin. We briefly discuss these key issues in this section, and in more detail later in this preamble. The Summary and Analysis of Comments document provides our responses to the comments we received; it is located in the docket for this rulemaking and also on EPA's Web site at

www.epa.gov/otaq/tier3.htm

1. Major Public Comments and Key Changes From the Proposal

a. Start Date and Lead Time Issues

(1) Gasoline Sulfur Control Program

Many stakeholders commented on the proposed 2017 start date of the Tier 3 program, with state and NGO organizations supporting finalizing the standards as proposed. Conversely, refiners, importers, and others in the fuel industry commented that they believed the proposed start date would not provide a sufficient amount of lead time to meet the requirements of the Tier 3 program, and that EPA has historically provided at least four years of lead time in previous fuels rulemakings. These commenters noted that five years of lead time is needed to allow for necessary refinery changes to be made during a refinery's normal turnaround/shutdown schedule (these occur every four years, on average) and to allow adequate time for the permitting process. These commenters also stated that, given the proposed flexibility provisions for vehicles, that a 2017 fuel program start date was not truly needed to enable the vehicle technology. Further, these commenters stated that they believed insufficient lead time would drive up the costs for regulated entities as they would need to do unscheduled shutdowns to install and/or revamp equipment to meet the proposed standards. Lastly, they stated that the uncertainty regarding the potential availability of credits would make meeting a 2017 start date more challenging.

As discussed in greater detail in Section V below, we are finalizing the proposed start date of January 1, 2017. We understand refiners' concerns,

including their concerns over the necessary capital investments and potential off-cycle turnarounds/shutdowns to make refinery modifications for Tier 3. In light of these concerns, we are finalizing additional flexibilities beyond those already in the proposal and we are confident that the program being finalized today addresses these concerns. Considering all the flexibilities offered to regulated parties, there is, in effect, nearly 6 years of time to comply provided for those refineries that may need it. As discussed in Section V.D, we are finalizing a credit averaging, banking, and trading (ABT) program that will allow for a smooth transition from the Tier 2 to Tier 3 ABT programs (including provisions for early credit generation beginning in 2014). These early credit provisions, coupled with the ability to carry over credits from Tier 2 into Tier 3 (an additional flexibility being finalized today that was not part of the proposal), will allow for early actions to reduce sulfur levels by some refineries to be used to delay the need for actions at other refineries until 2020. This structure of the ABT program allows refiners and importers the flexibility to choose the most economical compliance strategy—investment in technology, use of credits, or both—for meeting the Tier 3 average gasoline sulfur standard. In addition, approved small refiners and small volume refineries are given an additional three years from the January 1, 2017, Tier 3 program start date to comply (January 1, 2020).

We proposed that the Tier 2 ABT program would not only be separate from the Tier 3 ABT program, but that it would also end at the start of the Tier 3 program in 2017. The implications of this meant that any Tier 2 credits generated after 2012 would run the risk of expiring before the end of their full five-year life if they were not used before January 1, 2017. Commenters requested that EPA consider allowing such Tier 2 “banked” credits to receive their full five-year life. This would eliminate any incentive refiners may have to use these credits prior to the end of the Tier 2 program to raise their in-use sulfur levels. The ABT program that we are finalizing today enables a seamless transition from Tier 2 to Tier 3, including an allowance for Tier 2 banked credits to be used for their full five-year life or through December 31, 2019, whichever is earlier. Not only does this provision effectively provide more lead time and flexibility for refiners and importers, but we believe these banked credits will help to provide certainty of the availability of credits for refiners and importers who may want to rely on them for compliance.

Finally, as discussed in Section V.E.2, we are also finalizing hardship provisions that allow refiners to petition for delayed compliance, on a case-by-case basis, for situations of extreme hardship or extreme unforeseen circumstances. These provisions, similar to those implemented in past fuel rulemakings, provide a safety valve should all the other flexibilities provided prove insufficient. As part of these hardship provisions, we are finalizing the ability for refiners to carry a deficit for up to 3 years, providing them with yet additional flexibility during the transition to Tier 3 should it prove necessary.

(2) Vehicle Emission Control Program

There were no major concerns raised for the proposed MY 2017 start date for lighter light-duty vehicles, although commenters from the auto manufacturing industry raised concerns about the lead time we proposed for heavier light-duty vehicles. Specifically, commenters pointed to Clean Air Act section 202(a)(3)(C) that, for vehicles over 6,000 lbs GVWR, requires that EPA emission standards provide at least four years of lead time and three years of regulatory stability.

In light of this statutory requirement, in addition to the primary declining fleet average standards starting in MY 2018 for heavier vehicles, EPA proposed an alternative phase-in schedule for any manufacturer that prefers a longer lead time and annual stability for these vehicles in lieu of the declining fleet average standards option. The commenters stated that the proposed alternative pathway would be too difficult to take advantage of in comparison to the primary program and thereby failed to comply with the Clean Air Act.

In considering these comments, EPA also considered that during the development of the Tier 3 program and in their comments, the same auto industry commenters consistently urged EPA to design the Tier 3 program to harmonize with the California LEV III standards as closely and as early as possible. As discussed in detail below in Section IV.A, extensive data that EPA has generated or received continue to support the conclusion that the primary fleet-average standards provide a compliance path that is feasible across the industry and that closely harmonizes with LEV III. EPA believes that we have reasonably resolved these somewhat competing concerns—early harmonization vs. additional lead time—by finalizing the primary declining fleet average standards as proposed while also finalizing revised alternative phase-in compliance schedules (see Section IV.A.2.c). In response to the comments on this topic, we have revised the alternative phase-in schedules to reduce their associated burden for manufacturers, while still maintaining environmental benefits that are equivalent to the primary program. We also include provisions in the percent-of-sales phase-in alternatives that allow manufacturers to exclude vehicle models that begin their 2019 model year production early in 2018, in order to provide four years of lead time.

b. Emissions Test Fuel

In-use gasoline has changed considerably since EPA last revised specifications for the test gasoline used in emissions testing of light- and heavy-duty vehicles. Perhaps most importantly, gasoline containing 10 percent ethanol by volume (E10) has replaced non-oxygenated gasoline (E0) across the country. As a result, we are updating federal emissions test fuel specifications to better match in-use fuel.

In the NPRM, EPA proposed that the specified gasoline for emissions testing be changed from E0 to E15 as a forward-looking approach. Since then, several factors have led EPA to reconsider that approach, including minimal proliferation on a national scale of stations offering E15 and the complexities that E15 would introduce for long-term harmonization with California's use of E10 in their LEVIII program. We received comments from a broad set of stakeholders including the auto and oil industries, states, and NGOs with a general consensus that E15 would not be appropriate as the official test fuel at this time. Ethanol industry commenters supported E15 certification fuel, but provided no timeline by which this blend level would be representative of in-use fuel. In light of the comments received and EPA's assessment of the current and projected levels of ethanol in gasoline in use, we are finalizing E10 as the new emissions test fuel.

In deciding to finalize E10 test fuel, EPA considered whether to change the volatility of the test fuel, typically expressed as pounds per square inch (psi) Reid Vapor Pressure (RVP). As discussed in detail in Section IV.F, after considering technical and policy implications as well as stakeholder comments, we have concluded that the most appropriate approach is to maintain an RVP of 9 psi for the E10 emissions test fuel at this time. EPA considered raising test fuel RVP to 10

psi, but decided to leave it unchanged at 9 psi based on what would have been the associated increase in stringency of the Tier 3 evaporative standard with 10 psi and the loss of regulatory harmony on evaporative emissions with California's LEV III program.

As a result, after reassessing market trends and considering comments, EPA concludes that the most appropriate approach is to finalize an ethanol content of 10 percent and an RVP of 9 psi for emissions test gasoline. We will continue to monitor ethanol trends in the gasoline market, as discussed later in this preamble.

c. Gasoline Sulfur Caps

As described in more detail in Section V.C. we proposed two options for the Tier 3 per-gallon sulfur caps—maintaining the Tier 2 refinery gate sulfur cap of 80 ppm (with a 95 ppm downstream sulfur cap), and lowering to a 50 ppm refinery gate sulfur cap beginning January 1, 2020 (with a 65 ppm downstream cap). We received comments supporting lower per-gallon caps which noted potential environmental benefits, greater certainty that vehicles would see lower and more uniform gasoline sulfur levels, and the ability to enable new vehicle technologies requiring very low sulfur levels. Conversely, comments received in support of maintaining the Tier 2 per-gallon caps cited concerns on cost, flexibility for turnarounds/unplanned shutdowns (due to refinery fires, natural disasters, etc.), and gasoline supply and/or price impacts.

Analysis performed since the time of the proposal found that a lower refinery gate cap would likely result in higher costs to the fuels industry and a decreased ability to handle off-spec product (potentially impacting gasoline supply and pricing), without any significant increase in the nationwide emissions reductions provided by the Tier 3 program. Thus, in today's action we are retaining the Tier 2 per-gallon sulfur caps. The 80 ppm refinery gate cap will provide refiners needed flexibility in allowing for naturally-occurring fuel batch variability, as well as more certainty that they will be able to continue producing and distributing gasoline during turnarounds/upsets to avoid a total shutdown. It will also provide more certainty for transmix processors, additive manufacturers, and other downstream parties in producing gasoline.

However, we do understand commenters' concerns that retaining the Tier 2 sulfur caps might create regional differences in the benefits of the Tier 3 program. Therefore we will continue to monitor in-use sulfur levels and their impact on vehicle emissions to ascertain whether a future reduction in the per-gallon cap may be necessary.

d. Effect of Gasoline Sulfur on Tier 3 Vehicle Emissions

The need for and level of gasoline sulfur control was a key issue raised in public comments. The petroleum industry raised concerns that there was insufficient basis for the proposed 10 ppm average sulfur level, while auto manufacturers and emissions control equipment manufacturers stressed that the feasibility of the Tier 3 vehicle standards was dependent on near-zero gasoline sulfur levels. This issue is discussed in detail below in Section IV.A.6. In sum, EPA believes that the range of studies conducted by EPA and others in recent years, along with the comments submitted by the auto industry and emissions control manufacturers during the comment period and more recently, strongly reinforce our conclusion that the impact of gasoline sulfur poisoning on exhaust catalyst performance is significant.

Sulfur is a well-known catalyst poison. The nature of sulfur's interactions with active catalytic materials is complex and varies with catalyst composition, exhaust gas composition, and exhaust temperature. Thus, even if a manufacturer were able to certify a new vehicle to the new stringent standards, the manufacturer's ability to maintain the emission performance of that vehicle in-use is greatly jeopardized if the vehicle is being operated on gasoline sulfur levels greater than 10 ppm. In fact, due to the variation in actual vehicle operation, any amount of gasoline sulfur will deteriorate catalyst efficiency. Vehicle manufacturers and suppliers, both individually and through their trade associations, stressed the need for gasoline sulfur to be reduced to near zero levels in order for them to meet the proposed standards. However, we believe that a 10 ppm average sulfur level is sufficiently low to enable compliance with the Tier 3 vehicle standards, and as described below and in Section V, reducing sulfur levels further would cause sulfur control costs to quickly escalate.

Taken together, this information provides a compelling argument that the fleetwide Tier 3 vehicle standards are achievable only with a reduction of gasoline sulfur content from the current 30 ppm average down to a 10 ppm average.

e. SFTP (US06) PM Standard for Light-Duty Vehicles

The final Tier 3 vehicle standards are largely unchanged from their proposed levels. One change from the proposal is the PM emissions standards as measured on the US06 test cycle. The US06 cycle is part of the composite Supplemental Federal Test Procedure (SFTP) and simulates aggressive driving. The US06 PM standards are part of the suite of Tier 3 tailpipe standards that limit emissions under a wide range of common vehicle driving conditions. Newer emissions test data presented in the NPRM, as well as more recent additional test data submitted in public comments, show that a numerically lower US06 PM standard is feasible and appropriately reflects the actual emissions performance achieved by many vehicles in the fleet today while preventing increased emissions in the future.

Taken together, the test results clearly show that most current light-duty vehicles—regardless of engine technology, emission control strategy, or vehicle size—are performing at much lower US06 emission levels than previously documented. Based on these newer data, we believe that it is appropriate to finalize a numerically lower US06 PM emission standard for LDVs, LDTs, and MDPVs, and to set a single standard for both lighter and heavier vehicles in this vehicle segment. In general, the final US06 PM standard for these vehicles begins to phase in at a level of 10 mg/mi in MYs 2017 and 2018, stepping down to a level of 6 mg/mi in MY2019. See Section IV.A.4.b for additional discussion of the US06 standards and how they will phase in.

2. Key Components of the Tier 3 Program

a. Tailpipe Standards for Light-Duty Vehicle, Light-Duty Truck, and Medium-Duty Passenger Vehicle Tailpipe Emissions

We are establishing a comprehensive program that includes new fleet-average standards for the sum of NMOG and NO

tailpipe emissions (presented as NMOG+NO

) as well as new per-vehicle standards for PM.

These standards, when applied in conjunction with reduced gasoline sulfur content, will result in very significant improvements in vehicle emissions from the levels of the Tier 2 program. For these pollutants, the standards are measured on test procedures that represent a range of

vehicle operation, including the Federal Test Procedure (or FTP, simulating typical driving) and the Supplemental Federal Test Procedure (or SFTP, a composite test simulating higher ambient temperatures, higher vehicle speeds, and quicker accelerations). In addition to the standards, we are extending the regulatory useful life period during which the standards apply (see Section IV.A.7.b below) and making test fuel more representative of expected real-world fuel (see Section I.B.2.e below). The final standards are in most cases identical to those of California's LEVIII program, which provides the 50-state harmonization strongly supported by the auto industry.

A discussion of the reasons for combining NMOG and NO

for this purpose is in Section IV.A.3.a below.

As proposed, the new Tier 3 FTP and SFTP NMOG+NO

standards are fleet-average standards, meaning that a manufacturer calculates the average emissions of the vehicles it sells in each model year and compares that average to the applicable standard for that model year. The manufacturer certifies each of its vehicles to a per-vehicle “bin” standard (see Section IV.A.2) and sales-weights these values to calculate its fleet-average NMOG+NO

emissions for each model year. Table I-1 summarizes the fleet average standards for NMOG+NO

evaluated over the FTP. The standards for light-duty vehicles begin in MY 2017 at a level representing a 46 percent reduction from the Tier 2 requirements. For the light-duty fleet over 6000 lbs GVWR, and MDPVs, the standards apply beginning in MY 2018. As shown, these fleet-average standards decline during the first several years of the program, becoming increasingly stringent until ultimately reaching an 81 percent reduction when the transition is complete. The FTP NMOG+NO

program includes two separate sets of declining fleet-average standards, with LDVs and small light trucks in one grouping and heavier light trucks and MDPVs in a second grouping, that converge at 30 milligrams per mile (mg/mi) in MY 2025 and later. As mentioned above, we are also providing alternative percent phase-in schedules for this and the other light-duty standards.

Table I-1—Tier 3 LDV, LDT, and MDPV Fleet Average FTP NMOG+NO

Standards

[mg/mi]

Model year

2017

2018

2019

2020

2021

2022

2023

2024

2025 and later

LDV/LDT1

LDT2,3,4 and MDPV

101

For LDV and LDTs above 6000 lbs GVWR and MDPVs, the fleet average standards apply beginning in MY 2018.

These standards apply for a 150,000 mile useful life. Manufacturers can choose to certify some or all of their LDVs and LDT1s to a useful life of 120,000 miles. If a vehicle model is certified to the shorter useful life, a proportionally lower numerical fleet-average standard applies, calculated by multiplying the respective 150,000 mile standard by 0.85 and rounding to the nearest mg. See Section IV.A.7.c.

Similarly, as proposed, the NMOG+NO

standards measured over the SFTP are fleet-average standards, declining from MY 2017 until MY 2025, as shown in Table I-2. In this case, the same standards apply to both lighter and heavier vehicles in the light-duty fleet. In MY 2025, the SFTP NMOG+NO

standard reaches its final fleet average level of 50 mg/mi.

Table I-2—Tier 3 LDV, LDT, and MDPV Fleet Average SFTP NMOG+NO

Standards

[mg/mi]

Model year

2017

2018

2019

2020

2021

2022

2023

2024

2025 and later

NMOG + NO

103

For LDVs and LDTs above 6000 lbs GVWR and MDPVs, the fleet average standards apply beginning in MY 2018.

As proposed, manufacturers can also earn credits if their fleet average NMOG+NO

performance is better than the applicable standard in any model year. Credits that have been previously banked or obtained from other manufacturers can be used, or credits can be traded to other manufacturers. Manufacturers would also be allowed to carry forward deficits in their credit balance. (See Sections IV.A.7.a and IV.A.7.m).

We are also establishing PM standards as part of the Tier 3 program, for both the FTP and US06 cycles (as described above, US06 is a component of the SFTP test). Research has demonstrated that the level of PM from gasoline light-duty vehicles is more significant than previously thought.

Although many vehicles today are performing at or near the levels of the new standards, the data indicate that improvements, especially in high-load fuel control and in the durability of engine components, are possible.

Nam, E.; Fulper, C.; Warila, J.; Somers, J.; Michaels, H.; Baldauf, R.; Rykowski, R.; and Scarbro, C. (2008). Analysis of Particulate Matter Emissions from Light-Duty Gasoline Vehicles in Kansas City, EPA420-R-08-010. Assessment and Standards Division Office of Transportation and Air Quality U.S. Environmental Protection Agency Ann Arbor, MI, April 2008.

Under typical driving, as simulated by the FTP, the PM emissions of most current-technology gasoline vehicles are fairly low at certification and in use, well below the Tier 2 PM standards. At the same time we see considerable variation in PM emissions among vehicles of various makes, models, and designs. As a result, as proposed, we are setting the new FTP PM standard at a level that will ensure that all new vehicles perform at the level already being achieved by well-designed Tier 2 vehicles. The PM standards apply to each vehicle separately (i.e., not as a fleet average). Also, in contrast to the declining NMOG+NO

standards, the

PM standard on the FTP for certification testing is 3 mg/mi for all vehicles and for all model years. As for the NMOG+NO

standards, for vehicles over 6000 lbs GVWR, the FTP PM standard applies beginning in MY 2018. Manufacturers can phase in their vehicle models as a percent of U.S. sales through MY 2022. Most vehicles are already performing at this stringent PM level, and the primary intent of the standard is to bring all light-duty vehicles to the typical level of PM performance being demonstrated by many of today's vehicles.

As proposed, the Tier 3 program also includes a temporary in-use FTP PM standard of 6 mg/mi for the testing of in-use vehicles that applies during the percent phase-in period only. This in-use standard will address the in-use variability and durability uncertainties that accompany the introduction of new technologies. Table I-3 presents the FTP certification and in-use PM standards and the phase-in percentages.

Table I-3—Phase-In for Tier 3 FTP PM Standards

2017

2018

2019

2020

2021

2022 and later

Phase-In (percent of U.S. sales)

100

Certification Standard (mg/mi)

In-Use Standard (mg/mi)

For LDVs and LDTs above 6000 lbs GVWR and MDPVs, the FTP PM standards apply beginning in MY 2018.

Manufacturers comply in MY 2017 with 20 percent of their LDV and LDT fleet under 6,000 lbs GVWR, or alternatively with 10 percent of their total LDV, LDT, and MDPV fleet.

Finally, as discussed in Section I.B.1.e above, the Tier 3 program includes PM standards evaluated over the US06 driving cycle (the US06 is one part of the SFTP procedure) of 10 mg/mi through MY 2018 and of 6 mg/mi for 2019 and later model years, for light-duty vehicles. As in the case of the FTP PM standards, the intent of the US06 PM standard is to bring the emission performance of all vehicles to that already being demonstrated by many vehicles in the current light-duty fleet.

b. Heavy-Duty Vehicle Tailpipe Emissions Standards

As discussed in detail in Section IV.B, we are setting Tier 3 exhaust emissions standards for complete heavy-duty vehicles (HDVs) between 8,501 and 14,000 lbs GVWR. Vehicles in this GVWR range are often referred to as Class 2b (8,501-10,000 lbs) and Class 3 (10,001-14,000 lbs) vehicles, and are typically heavy-duty pickup trucks and work or shuttle vans. Most are built by companies with even larger light-duty truck markets, and as such they frequently share major design characteristics and emissions control technologies with their LDT counterparts. However, in contrast to the largely gasoline-fueled LDT fleet, roughly half of the heavy-duty pickup and van fleet in the U.S. is diesel-fueled. This is an important consideration in setting emissions standards, as diesel engine emissions control strategies differ from those of gasoline engines.

As proposed, the key elements of the Tier 3 program for HDVs parallel those being adopted for passenger cars and LDTs, with adjustments in standard levels, emission test requirements, and implementation schedules appropriate to this sector. These key elements include combined NMOG+NO

declining fleet average standards, a phase-in of PM standards, adoption of a new emissions test fuel for gasoline-fueled vehicles, extension of the regulatory useful life to 150,000 miles or 15 years (whichever occurs first), and a first-ever requirement for HDVs to meet standards over an SFTP drive cycle that addresses real-world driving modes not well-represented by the FTP cycles.

We are adopting the Class 2b and Class 3 fleet average NMOG+NO

standards shown in Table I-4, as proposed. The standards become more stringent in successive model years from 2018 to 2022, with voluntary standards made available in 2016 and 2017, all of which are set at levels that match those of California's LEV III program for these classes of vehicles. Each covered HDV sold by a manufacturer in each model year contributes to this fleet average based on the mg/mi NMOG+NO

standard level of the “bin” declared for it by the manufacturer, who chooses from a set of seven discrete Tier 3 bins specified in the regulations. These bin standards then become the compliance standards for the vehicle over its useful life, with some adjustment provided for in-use testing in the early model years of the program.

As proposed, manufacturers can also earn credits for fleet average NMOG+NO

levels below the standard in any model year. Tier 3 credits that were previously banked, obtained from other manufacturers, or transferred across the Class 2b/Class 3 categories can be used to help demonstrate compliance. Unused credits expire after 5 model years. Manufacturers will also be allowed to carry forward deficits in their credit balance for up to 3 model years.

Table I-4—Tier 3 HDV Fleet Average FTP NMOG+NO

Standards

[mg/mi]

Voluntary

Required program

Model Year

2016

2017

2018

2019

2020

2021

2022 and later.

Class 2b

333

310

278

253

228

203

178.

Class 3

548

508

451

400

349

298

247.

We are adopting the proposed FTP PM standards of 8 mg/mi and 10 mg/mi for Class 2b and Class 3 HDVs, respectively, phasing in as an increasing percentage of a manufacturer's sales per year. We are adopting the same phase-in schedule as for the light-duty sector during model years 2018-2019-2020-2021: 20-40-70-100 percent, respectively, and a more flexible but equivalent alternative PM phase-in is also being adopted. Tier 3 HDVs will

also be subject to CO and formaldehyde exhaust emissions standards that are more stringent than the existing standards.

Finally, we are setting first-ever nationwide SFTP standards for HDVs to ensure a robust overall control program that precludes high off-FTP cycle emissions by having vehicle designers consider them in their choice of compliance strategies. As for light-duty vehicles, we are requiring that SFTP compliance be based on a weighted composite of measured emissions from testing over the FTP cycle, the SC03 cycle, and an aggressive driving cycle, with the latter tailored to various HDV sub-categories: the US06 cycle for most HDVs, the highway portion of the US06 cycle for low power-to-weight Class 2b HDVs, and the LA-92 (or “Unified”) cycle for Class 3 HDVs. The SFTP standards are the same as those adopted for California LEV III vehicles, and apply to NMOG+NO

, PM, and CO emissions.

The HDV program outlined above and described in detail in Section IV.B is substantially what we proposed. Commenters generally supported the scope, stringency, and implementation phase-in of this program. However, some industry commenters requested changes to some specific provisions of the proposal, and the program we are adopting reflects improvements we have made in response. These are: (1) A limited allowance for engine certification of Class 3 complete diesel vehicles to avoid a potential need for dual chassis- and engine-based certification and to better harmonize with LEV III, (2) relaxed interim in-use testing standards to facilitate a smooth transition to the Tier 3 standards and to better harmonize with LEV III, (3) adoption of combined NMOG+NO

standards for the two highest (interim) bins, with a restriction placed on NO

levels in certification testing, to enhance the utility of these bins and to better harmonize with LEV III, and (4) a provision in the percent-of-sales phase-in alternative to allow manufacturers to exclude vehicle models that begin their 2019 model year production early in 2018, in order to provide four years of lead time. Commenters also requested relaxed standards for testing at high altitudes and changes to the credits program structure for generation of early credits and use of LEV III-based “vehicle emission credits”, but we did not adopt these for reasons explained in Section IV.B.

Overall, we expect the Tier 3 program we are adopting for HDVs to result in substantial reductions in harmful emissions from this large fleet of work trucks and vans. The fully-phased in Tier 3 standards levels for NMOG+NO

and PM are on the order of 60 percent lower than the current standards that took full effect in the 2009 model year.

c. Evaporative Emission Standards

Gasoline vapor emissions from vehicle fuel systems occur when a vehicle is in operation, when it is parked, and when it is being refueled. These evaporative emissions, which occur on a daily basis from gasoline-powered vehicles, are primarily functions of temperature, fuel vapor pressure, and activity. EPA first instituted evaporative emission standards in the early 1970s to address emissions when vehicles are parked after being driven. These are commonly referred to as hot soak plus diurnal emissions. Over the subsequent years the test procedures have been modified and improved and the standards have become more numerically stringent. We have addressed emissions which arose from new fuel system designs by putting in place new requirements such as running loss emission standards and test procedure provisions to address permeation emissions. Subsequently standards were put in place to control refueling emissions from all classes of gasoline-powered motor vehicles up to 10,000 lbs GVWR. Evaporative and refueling emission control systems have been in place for most of these vehicles for many years. These controls have led to significant reductions, but evaporative and refueling emissions still constitute 30-40 percent of the summer on-highway mobile source hydrocarbon inventory. These fuel vapor emissions are ozone and PM precursors, and also contain air toxics such as benzene.

To control evaporative emissions, EPA is establishing more stringent standards that will require covered vehicles to have essentially zero fuel vapor emissions in use. These include more stringent evaporative emissions standards, new test procedures, and a new fuel/evaporative system leak emission standard. The program also includes refueling emission standards for all complete heavy-duty gasoline vehicles (HDGVs) over 10,000 lbs GVWR. EPA is including phase-in flexibilities as well as credit and allowance programs. The standards, harmonized with California's “zero evap” standards, are designed to allow for a use of common technology in vehicle models sold throughout the U.S. The level of the standard remains above zero to account for nonfuel background emissions from the vehicle hardware.

Requirements to meet the Tier 3 evaporative emission regulations phase in over a six model year period. We are finalizing three options for the 2017 model year, but after that the sales percentage requirements are 60 percent for MYs 2018 and 2019, 80 percent for model years 2020 and 2021, and 100 percent for model years 2022 and later. In Table I-5 we present the Tier 3 evaporative hot soak plus diurnal emission standards by vehicle class. The standards are approximately a 50 percent reduction from the existing standards. To enhance flexibility and reduce costs, EPA is finalizing provisions that allow manufacturers to generate allowances through early certifications (basically before the 2017 model year) and to demonstrate compliance using averaging concepts. Manufacturers may comply on average within each of the four vehicle categories, but not across these categories. EPA is not making any changes to the existing light-duty running loss or refueling emission standards, with the exception of the certification test fuel requirement discussed in Section I.B.2 below.

Table I-5—Tier 3 Evaporative Emission Standards

[g/test]

Vehicle class

Highest hot soak +

diurnal level

(over both 2-day and

3-day diurnal tests)

LDV, LDT1

0.300

LDT2

0.400

LDT3, LDT4, MDPV

0.500

HDGVs

0.600

Flexible Fuel Vehicles (FFVs) must meet the same evaporative emission standards as non-FFVs using Tier 3 emissions certification test fuel. However, FFVs must meet the refueling emission standards using 10 psi RVP fuel to account for emissions resulting from commingling with non-E85 blends that may be in the vehicle's fuel tank.

EPA is establishing the canister bleed emission test procedure and emission standard to help ensure fuel vapor emissions are eliminated. Under this provision, manufacturers are required to measure diurnal emissions over the 2-day diurnal test procedure from just the fuel tank and the evaporative emission canister and comply with a 0.020 gram per test (g/test) standard for all LDVs, LDTs, and MDPVs, without averaging. The corresponding canister bleed test standard for HDGVs is 0.030 g/test. The Tier 3 evaporative emission standards will be phased in over a period of six model years between MY 2017 and MY

2022, with the leak test phasing in beginning in 2018.

Data from in-use evaporative emissions testing indicates that vapor leaks from vehicle fuel/evaporative systems are found in the fleet and that even very small leaks have the potential to make significant contributions to the mobile source VOC inventory. To help address this issue, we are also adding a new standard and test procedure to control vapor leaks from vehicle fuel and vapor control systems. The standard will prohibit leaks with a cumulative equivalent diameter of 0.02 inches or greater. We are adding this simple and inexpensive test and emission standard to help ensure vehicles maintain zero fuel vapor emissions over their full useful life. New LDV, LDT, MDPV, and HDGV equal to or less than 14.000 lbs GVWR meeting the Tier 3 evaporative emission regulations are also required to meet the leak standard beginning in the 2018 model year. Manufacturers must comply with the leak standard phase-in on the same percentage of sales schedule as that for the Tier 3 evaporative emission standards. Manufacturers will comply with the leak emission standard during certification and in use. The leak emission standard does not apply to HDGVs above 14,000 lbs GVWR.

EPA is also establishing new refueling emission control requirements for all complete HDGVs equal to or less than 14,000 lbs GVWR (i.e., Class 2b/3 HDGVs), starting in the 2018 model year, and for all larger complete HDGVs by the 2022 model year. The existing refueling emission control requirements apply to complete Class 2b HDGVs, and EPA is extending those requirements to other complete HDGVs, since the fuel and evaporative control systems on these vehicles are very similar to those on their lighter-weight Class 2b counterparts.

d. Onboard Diagnostic Systems (OBD)

EPA and CARB both have OBD regulations applicable to the vehicle classes covered by the Tier 3 emission standards. In the past the requirements have been very similar, so most manufacturers have met CARB OBD requirements and, as permitted in our regulations, EPA has generally accepted compliance with CARB's OBD requirements as satisfying EPA's OBD requirements. Over the past several years CARB has upgraded its requirements to help improve the effectiveness of OBD in ensuring good in-use exhaust and evaporative system emissions performance. We have reviewed these provisions and agree with CARB that these revisions will help to improve in-use emissions performance, while at the same time harmonizing with the CARB program. Toward that end, we are adopting and incorporating by reference the current CARB OBD regulations, effective for the 2017 MY, with a few minor differences including phase-in flexibility provisions and specific additions to enhance the implementation of the leak standard. EPA is retaining the provision that certifying with CARB's program would permit manufacturers to seek a separate EPA certificate on that basis.

e. Emissions Test Fuel

As described above, after reassessing market trends and considering comments, EPA is finalizing E10 as the ethanol blend level in emissions test gasoline for Tier 3 light-duty and heavy-duty gasoline vehicles. We will continue to monitor the in-use gasoline supply and based on such review may initiate rulemaking action to revise the specifications for emissions test fuel to include a higher ethanol blend level. EPA is also making additional changes that are consistent with CARB's LEV III emissions test fuel specifications, including new specifications for octane, distillation temperatures, aromatics, olefins, sulfur and benzene. (See Section IV.F below for a detailed discussion of all the revised emission test fuel parameters.)

As discussed in Sections IV.A.7.d (tailpipe emission testing) and IV.C.5.b (evaporative emission testing), we are requiring certification of all Tier 3 light-duty and chassis-certified heavy-duty gasoline vehicles on federal E10 test fuel. The new test fuel specifications will apply to new vehicle certification, assembly line, and in-use testing.

With a change in the ethanol content of the test fuel, EPA also needed to consider whether a change is warranted in the volatility of the test fuel, typically expressed as pounds per square inch (psi) Reid Vapor Pressure (RVP). As discussed in detail in Section IV.F below, after considering several technical and policy implications as well as stakeholder comments, EPA has concluded that the most appropriate approach is to maintain an RVP of 9 psi for the E10 certification fuel at this time.

In addition to finalizing a new E10 emissions test fuel, we are also finalizing detailed specifications for the E85 emissions test fuel used for flexible fuel vehicle (FFV) certification, as discussed in Section IV.F.3.

This will resolve uncertainty and confusion in the certification of FFVs designed to operate on ethanol levels up to 83 percent. Furthermore, we allow vehicle manufacturers to request approval for an alternative certification fuel such as a high-octane 30 percent ethanol by volume blend (E30) for vehicles that may be optimized for such fuel.

Flexible fuel vehicles are currently required to meet emissions certification requirements using both E0 and E85 test fuels. However, there were no detailed regulatory specifications regarding the composition of E85 test fuels before those finalized today.

f. Fuel Standards

Under the Tier 3 fuel program, gasoline must contain no more than 10 ppm sulfur on an annual average basis beginning January 1, 2017. Similar to the Tier 2 gasoline program, the Tier 3 program will apply to gasoline in the U.S. and the U.S. territories of Puerto Rico and the Virgin Islands, excluding California. The program will result in gasoline that contains, on average, two-thirds less sulfur than it does today. In addition, following discussions with numerous refiners and other segments of the fuel market (e.g., pipelines, terminals, marketers, ethanol industry representatives, transmix processors, additive manufacturers, etc.), the Tier 3 fuel program contains considerable flexibility to ease both initial and long-term implementation of the program. The program that we are finalizing today includes an averaging, banking, and trading (ABT) program that allows refiners and importers to spread out their investments over nearly a 6-year period through the use of an early credit program and then rely on ongoing nationwide averaging to meet the 10 ppm sulfur standard. In addition there is a three-year delay for small refiners and “small volume refineries”. As a result of the early credit program, we anticipate considerable reductions in gasoline sulfur levels prior to 2017, with a complete transition to the 10 ppm average occurring by January 1, 2020. For more information on the gasoline sulfur program flexibilities, refer to Section V.E.

Under today's Tier 3 gasoline sulfur program, we are maintaining the current 80 ppm refinery gate and 95 ppm downstream per-gallon caps. We also evaluated and sought comment on the potential of lowering the per-gallon caps. While there are advantages and disadvantages with each of the sulfur cap options that we proposed, we believe that retaining the current Tier 2 sulfur caps is prudent at this time, as explained in more detail in Section V.C. Further, the stringency of the 10 ppm annual average standard will result in reduced gasoline sulfur levels nationwide. Today's program requires

that manufacturers of gasoline additives that are used downstream of the refinery at less than 1 volume percent must limit the sulfur contribution to the finished gasoline from the use of their additive to less than 3 ppm when the additive is used at the maximum recommended treatment rate (see Section V.C.2). This requirement will preclude the unnecessary use of high sulfur content additives in gasoline.

The vehicle emissions standards finalized today are fuel-neutral (i.e., they are applicable regardless of the type of fuel that the vehicle is designed to use). There currently are no sulfur standards for the fuel used in compressed natural gas (CNG) and liquid propane gas (LPG) vehicles. We requested comment on whether it is necessary for EPA to establish sulfur standards for CNG and LPG to enable them meeting more stringent vehicle emissions standards. EPA is deferring finalizing in-use sulfur requirements for CNG/LPG in this final rule to provide additional time to work with stakeholders to collect data on current CNG/LPG sulfur content, to determine whether additional control of in-use CNG/LPG sulfur content is needed, and to evaluate the feasibility and costs associated with potential additional sulfur controls (see Section V.J). Given that the information provided suggests that CNG/LPG sulfur levels tend to be low already, the vehicle emissions standards finalized today will apply to CNG/LPG vehicles in addition to vehicles fueled on gasoline, diesel fuel, or any other fuel. The sulfur content of highway diesel fuel is already required to meet a 15 ppm sulfur cap, which is sufficient for diesel fuel vehicles to meet the Tier 3 emissions standards.

As the number of flex-fuel vehicles (FFVs) in the in-use fleet increases, it is becoming increasingly important that all fuels used in FFVs, not just gasoline, meet fuel quality standards. A lack of clarity regarding the standards that apply to fuels used in FFVs could also act to impede the further expansion of ethanol blended fuels with concentrations greater than 15 volume percent, which is important to satisfying the requirements of the RFS2 program. Hence, we sought comment on appropriate regulatory mechanisms to implement in-use quality standards for E51-83 and E16-50 in the Tier 3 proposal. Additional work is needed on some issues that could not be accommodated within the timeline for this Tier 3 final rule. Therefore, we are choosing not to finalize these provisions at this time. We intend to finalize in-use fuel quality standards for E51-83 and perhaps E16-50 as well in a follow-up final rule.

g. Regulatory Streamlining and Technical Amendments

This action also includes a number of items to help streamline the in-use fuels regulations at 40 CFR parts 79 and 80. The majority of these items involve clarifying vague or inconsistent language, removal or updating of outdated provisions, and decreasing in frequency and/or volume of reporting burden where data are no longer needed or are redundant with other EPA fuels programs. In general, we believe that these changes will reduce the burden on industry and allow the standards and resulting environmental benefits to be achieved as early as possible with no expected loss in environmental control. In some cases, these regulatory streamlining items are non-substantive amendments that correct minor errors or inconsistencies in the regulations.

The regulatory streamlining items that we are finalizing for the in-use fuels regulations are changes that we believe are straightforward and should be made quickly.

This action also includes a variety of technical amendments to certification-related requirements for engine and vehicle emission standards; adjusting the fuel economy label provisions to correspond to the new Tier 3 standards, removing obsolete regulatory text, and making several minor corrections and clarifications.

Please refer to Section VI for a complete discussion of technical amendments and regulatory streamlining provisions and issues.

C. What will the impacts of the standards be?

The final Tier 3 vehicle and fuel standards together will reduce dramatically emissions of NO

, VOC, PM

2.5

, and air toxics. The gasoline sulfur standards, which will take effect in 2017, will provide large immediate reductions in emissions from existing gasoline vehicles and engines. NO

emissions are projected to be reduced by about 260,000 tons, or about 10 percent of emissions from on-highway vehicles, in 2018, and these emission reductions will increase over time as newer vehicles become a larger percentage of the fleet. In 2030, when 70 percent of the miles travelled are projected to be from vehicles that meet the fully phased-in Tier 3 standards, we expect the NO

and VOC emissions to be reduced by about 330,000 tons and 170,000 tons, respectively, or 25 percent and 16 percent of emissions from on-highway vehicles compared to their 2030 levels without the Tier 3 program. Emissions of CO are projected to decrease by almost 3.5 million tons, or 24 percent of emissions from on-highway vehicles. Emissions of many air toxics will also be reduced, including benzene, 1,3-butadiene, acetaldehyde, formaldehyde, acrolein and ethanol, with reductions projected to range from 10 to nearly 30 percent of national emissions from on-highway vehicles. We expect these reductions to continue beyond 2030 as more of the fleet continues to turn over to Tier 3 vehicles; for example, by 2050, when nearly all of the fleet will have turned over to vehicles meeting the fully phased-in Tier 3 standards, we estimate the Tier 3 program will reduce on-highway emissions of NO

and VOC nearly 31 percent from the level of emissions projected without Tier 3 controls.

To estimate the benefits of the final Tier 3 rule, we performed air quality modeling for the year 2030.

These reductions in emissions of NO

, VOC, PM

2.5

and air toxics from the Tier 3 standards are projected to lead to significant decreases in ambient concentrations of ozone, PM

2.5

and air toxics (including notable nationwide reductions in benzene concentrations) by 2030, and will immediately reduce ozone in 2017 when the sulfur controls take effect. Additional information on the emission and air quality impacts of the final Tier 3 program is presented in Sections III.B and C.

Exposure to ambient concentrations of ozone, PM

2.5

, and air toxics is linked to adverse human health impacts such as premature deaths as well as other important public health and environmental effects (see Section II.B). The final Tier 3 standards are expected to reduce these adverse impacts and yield significant benefits, including those we can monetize and those we are unable to quantify. We estimate that by 2030, the emission reductions of the Tier 3 standards will annually prevent between 660 and 1,500 PM-related premature deaths, between 110 and 500 ozone-related premature deaths, 81,000 work days lost, 210,000 school absence days, and approximately 1.1 million minor restricted-activity days. The estimated annual monetized health benefits of the Tier 3 standards in 2030 (2011$) is between $7.4 and $19 billion, assuming a 3-percent discount rate (or between $6.7 billion and $18 billion assuming a 7-percent discount rate). We project the final fuel standards to cost on average 0.65 cent (i.e., less than a penny) per gallon of gasoline, and the final vehicle standards to have an

average cost that increases in proportion to the increase in stringency during the phase-in period, from $28 per vehicle in 2017 to $72 per vehicle in 2025, when the standards are fully phased in. We estimate the annual cost of the overall program in 2030 will be approximately $1.5 billion, and the 2030 benefits will be between 4.5 and 13 times the costs of the program.

The estimated benefits in Table I-6 include all of the human health impacts we are able to quantify and monetize at this time. However, the full complement of human health and welfare effects associated with PM, ozone and air toxics remain unquantified because of current limitations in methods and/or available data. As a result, the health benefits quantified in this section are likely underestimates of the total benefits attributable to the final standards. See Sections VII and VIII for detailed descriptions of the costs and benefits of this action.

Table I-6—Summary of Estimated Annual Benefits and Costs Associated With the Final Tier 3 Program

[Billions, 2011$]

Description

2030

Vehicle Program Costs

$0.76

Fuels Program Costs

$0.70

Total Estimated Costs

$1.5

Total Estimated Health Benefits:

3 percent discount rate

$7.4-$19

7 percent discount rate

$6.7-$18

Annual Net Benefits (Total Benefits−Total Costs):

3 percent discount rate

$5.9-$18

7 percent discount rate

$5.2-$17

Notes:

All estimates represent annual benefits and costs anticipated for the year 2030. Totals are rounded to two significant digits and may not sum due to rounding.

The calculation of annual costs does not require amortization of costs over time. Therefore, the estimates of annual cost do not include a discount rate or rate of return assumption (see Section VII of the preamble for more information on vehicle and fuel costs).

Total includes ozone and PM2

5 estimated benefits. Range was developed by adding the estimate from the Bell et al., 2004 ozone premature mortality function to PM2

5-related premature mortality derived from the American Cancer Society cohort study (Krewski et al., 2009) for the low estimate and ozone premature mortality derived from the Levy et al., 2005 study to PM2

5-related premature mortality derived from the Six-Cities (Lepeule et al., 2012) study for the high estimate.

Annual benefits analysis results reflect the use of a 3 percent and 7 percent discount rate in the valuation of premature mortality and nonfatal myocardial infarctions, consistent with EPA and OMB guidelines for preparing economic analyses.

Valuation of premature mortality based on long-term PM exposure assumes discounting over the SAB recommended 20-year segmented lag structure described in the Regulatory Impact Analysis for the 2012 PM National Ambient Air Quality Standards (December, 2012).

Not all possible benefits are quantified and monetized in this analysis; the total monetized benefits presented here may therefore be underestimated. Potential benefit categories that have not been quantified and monetized, due to current limitations in methods and/or data availability, are listed in Table VIII-2. For example, we have not quantified a number of known or suspected health and welfare effects linked with reductions in ozone and PM (e.g., reductions in heart rate variability, reduced material damage to structures and cultural monuments, and reduced eutrophication in coastal areas). We are also unable to quantify health and welfare benefits associated with reductions in air toxics.

II. Why is EPA taking this action?

The Clean Air Act authorizes EPA to establish emissions standards for motor vehicles to address air pollution that may reasonably be anticipated to endanger public health or welfare. EPA also has authority to establish fuel controls to address such air pollution. These statutory requirements are described in Section II.A.

Emissions from motor vehicles and their fuels contribute to ambient levels of ozone, PM, NO

, sulfur dioxide (SO

) and CO, which are all pollutants for which EPA has established health-based NAAQS. These pollutants are linked with respiratory and/or cardiovascular problems and other adverse health impacts leading to increased medication use, hospital admissions, emergency department visits, and premature mortality. Over 149 million people currently live in areas designated nonattainment for one or more of the current NAAQS for ozone, PM

2.5

, PM

, and SO

Data come from Summary Nonattainment Area Population Exposure Report, current as of December 5, 2013 at:

http://www.epa.gov/oar/oaqps/greenbk/popexp.html

and contained in Docket EPA-HQ-OAR-2011-0135.

Motor vehicles also emit air toxics, and the most recent available data indicate that the majority of Americans continue to be exposed to ambient concentrations of air toxics at levels which have the potential to cause adverse health effects, including cancer, immune system damage, and neurological, reproductive, developmental, respiratory, and other health problems.

A more detailed discussion of the health and environmental effects of these pollutants is included in Section II.B.

U.S. EPA. (2011) Summary of Results for the 2005 National-Scale Assessment.

www.epa.gov/ttn/atw/nata2005/05pdf/sum_results.pdf

Cars and light trucks also continue to be a significant contributor to air pollution directly near roads, with gasoline vehicles accounting for more than 50 percent of near-road concentrations of some criteria and toxic pollutants.

More than 50 million people live, work, or go to school in close proximity to high-traffic roadways, and the average American spends more than one hour traveling each day, with over 80 percent of daily trips occurring by personal vehicle.

Exposure to traffic-related pollutants has been linked with adverse health impacts such as respiratory problems (particularly in asthmatic children) and cardiovascular problems.

http://www.healtheffects.org.

Rowangould, G.M. (2013) A census of the US near-roadway population: public health and environmental justice considerations. Transportation Research Part D 25: 59-67.

U.S. Census Bureau (2011). Current Housing Reports, Series H150/09, American Housing Survey for the United States: 2009. U.S. Government Printing Office, Washington, DC. Available at

http://www.census.gov/hhes/www/housing/ahs/ahs09/ahs09.html.

Drago, R.(2011). Secondary activities in the 2006 American Time Use Survey. U.S. Bureau of Labor Statistics Working Paper 446. Available at

http://www.bls.gov.

U.S. Department of Transportation, Bureau of Transportation Statistics. (2003) National Household Travel Survey 2001 Highlights Report. Government Printing Office, Washington, DC. Available at

http://www.bts.gov/publications/highlights_of_the_2001_national_household_travel_survey/.

http://nhts.ornl.gov/publications.shtml.

In the absence of additional controls such as Tier 3 standards, many areas will continue to have ambient ozone and PM

2.5

concentrations exceeding the NAAQS in the future. States and local areas are required to adopt control measures to attain the NAAQS and, once attained, to demonstrate that control measures are in place sufficient to maintain the NAAQS for ten years (and eight years later, a similar demonstration is required for another ten-year period). The Tier 3 standards will be a critical part of many areas' strategies to attain and maintain the NAAQS. Maintaining the NAAQS has been challenging for some areas in the past, particularly those where high population growth rates lead to significant annual increases in vehicle trips and vehicle miles traveled. Our air quality modeling for this final rule, which is described in more detail in Section III.C, projects that in 2018 a significant number of counties outside

CA will be within 10 percent of the 2008 ozone NAAQS, in the absence of additional controls. These counties in particular will benefit from the Tier 3 standards as they work to ensure long-term maintenance of the NAAQS.

Section III provides more detail on how we expect this action will reduce motor vehicle emissions and ambient levels of pollution. We project that the Tier 3 program will meaningfully reduce ozone concentrations as early as 2017 (the first year of the program), and even more significantly in 2030. The estimated reductions are of significant enough magnitude to bring ozone levels in some counties from above the standard to below the standard, even without any additional controls. We also project that the Tier 3 standards will reduce ambient PM

2.5

concentrations.

Without this action to reduce nationwide motor vehicle emissions, areas would have to adopt other measures to reduce emissions from other sources under their state or local authority. Few other measures exist for providing multi-pollutant reductions of the same magnitude and cost-effectiveness as those expected from the Tier 3 standards. Furthermore, most states do not have the authority to lower the sulfur in gasoline, which is needed to immediately reduce emissions from the existing fleet and also enable new vehicles to meet the Tier 3 emissions standards throughout their useful life.

The projected reductions in ambient ozone and PM

2.5

that will result from the Tier 3 standards will provide significant health benefits. We estimate that by 2030, the standards will annually prevent between 660 and 1,500 PM-related premature deaths, between 110 and 500 ozone-related premature deaths, 81,000 work days lost, 210,000 school absence days, and approximately 1.1 million minor restricted-activity days (see Section VIII for more details). This action will also reduce air toxics; for example, we project that in 2030, the Tier 3 standards will decrease ambient benzene concentrations by 10-25 percent in some urban areas. Furthermore, the Tier 3 standards will reduce traffic-associated pollution near major roads.

EPA is finalizing Tier 3 vehicle and fuel standards as part of a comprehensive nationwide program for regulating all types of air pollution from motor vehicles. EPA recently finalized standards to reduce GHG emissions from light-duty vehicles, starting with model year 2017.

The Tier 3 standards in this final rule, which address non-GHGs, will be implemented on the same timeframe, thus allowing manufacturers to optimize their vehicle redesigns over both sets of standards. Furthermore, the Tier 3 vehicle and fuel standards are also closely aligned with California's LEV III program, in such a way that manufacturers will be able to design a single vehicle for nationwide sales. This reduces the cost of compliance for auto manufacturers.

77 FR 62623 (October 15, 2012).

This Tier 3 rulemaking responds to the President's request in his May 2010 memorandum for EPA to review the adequacy of its existing non-GHG standards for new motor vehicles and fuels, and to promulgate new standards, if necessary, as part of a comprehensive approach to regulating motor vehicles.

Based on our review, we have concluded that improved vehicle technology, combined with lower sulfur gasoline, make it feasible and cost-effective to reduce emissions well below the current Tier 2 levels. These emission reductions are necessary to reduce air pollution that is (and projected to continue to be) at levels that endanger public health and welfare.

The Presidential Memorandum is found at:

http://www.whitehouse.gov/the-press-office/presidential-memorandum-regarding-fuel-efficiency-standards

A. Basis for Action Under the Clean Air Act

1. Clean Air Act Section 202

We are setting motor vehicle emission standards under the authority of section 202 of the Clean Air Act. Section 202(a) provides EPA with general authority to prescribe vehicle standards, subject to any specific limitations elsewhere in the Act. EPA is setting standards for larger light-duty trucks and MDPVs under the general authority of section 202(a)(1) and under section 202(a)(3), which requires that standards applicable to emissions of hydrocarbons, NO

, CO and PM from heavy-duty vehicles

reflect the greatest degree of emission reduction available for the model year to which such standards apply, giving appropriate consideration to cost, energy, and safety. In addition, section 202(k) provides EPA with authority to issue and revise regulations applicable to evaporative emissions of hydrocarbons from all gasoline-fueled motor vehicles during: (1) Operation, and (2) over 2 or more days of nonuse; under ozone-prone summertime conditions. Regulations under section 202(k) shall take effect as expeditiously as possible and shall require the greatest degree of emission reduction achievable by means reasonably expected to be available for production during any model year to which the regulations apply, giving appropriate consideration to fuel volatility, and to cost, energy, and safety factors associated with the application of the appropriate technology. Further, section 206 and in particular section 206(d) of the Clean Air Act authorizes EPA to establish methods and procedures for testing whether a motor vehicle or motor vehicle engine conforms with section 202 requirements.

LDTs that have gross vehicle weight ratings above 6000 lbs and all MDPVs are considered “heavy-duty vehicles” under the CAA. See section 202(b)(3)(C). For regulatory purposes, we generally refer to those LDTs which are above 6000 lbs GVWR and at or below 8500 lbs GVWR as “heavy light-duty trucks” made up of LDT3s and LDT4s, and we have defined MDPVs primarily as vehicles between 8500 and 10000 lbs GVWR designed primarily for the transportation of persons. See 40 CFR 86.1803-01.

2. Clean Air Act Section 211

We are adopting gasoline sulfur controls pursuant to our authority under section 211(c)(1) of the CAA. This section allows EPA to establish a fuel control if at least one of the following two criteria is met: (1) The emission products of the fuel cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare; or (2) the emission products of the fuel will impair to a significant degree the performance of any emissions control device or system which is either in general use or which the Administrator finds has been developed to a point where in a reasonable time it will be in general use were the fuel control to be adopted. We are finalizing gasoline sulfur controls based on both of these criteria. Under the first criterion, we believe that gasoline with current levels of sulfur contributes to ambient levels of air pollution that endanger public health and welfare, as described in Section II.B. Under the second criterion, we believe that gasoline sulfur impairs the emissions control systems of vehicles, as discussed in Section III.A.2.

B. Overview of Public Health Impacts of Motor Vehicles and Fuels

Motor vehicles emit pollutants that contribute to ambient concentrations of ozone, PM, NO

, CO, and air toxics. Motor vehicles are significant contributors to emissions of VOC and NO

, which contribute to the formation of both ozone and PM

2.5

. Over 149 million people currently live in counties designated nonattainment for one or more of the NAAQS, and this figure does not include the people living in areas with a risk of exceeding the

NAAQS in the future.

The majority of Americans continue to be exposed to ambient concentrations of air toxics at levels which have the potential to cause adverse health effects.

In addition, populations who live, work, or attend school near major roads experience elevated exposure concentrations to a wide range of air pollutants.

Data come from Summary Nonattainment Area Population Exposure Report, current as of December 5, 2013 at:

http://www.epa.gov/oar/oaqps/greenbk/popexp.html

and contained in Docket EPA-HQ-OAR-2011-0135.

U.S. EPA. (2011) Summary of Results for the 2005 National-Scale Assessment.

www.epa.gov/ttn/atw/nata2005/05pdf/sum_results.pdf

Health Effects Institute Panel on the Health Effects of Traffic-Related Air Pollution. (2010) Traffic-related air pollution: a critical review of the literature on emissions, exposure, and health effects. HEI Special Report 17. Available at

http://www.healtheffects.org].

EPA has already adopted many emission control programs that are expected to reduce ambient pollution concentrations. As a result of these programs, the number of areas that continue to violate the ozone and PM

2.5

NAAQS or have high levels of air toxics is expected to continue to decrease. However, the baseline air quality modeling completed for this rule predicts that without additional controls there will continue to be a need for reductions in ozone, PM

2.5

and air toxics concentrations in some locations in the future. Section III.C of this preamble presents the air quality modeling results for this action.

1. Ozone

a. Background

Ground-level ozone pollution is typically formed through reactions involving VOC and NO

in the lower atmosphere in the presence of sunlight. These pollutants, often referred to as ozone precursors, are emitted by many types of pollution sources, such as highway and nonroad motor vehicles and engines, power plants, chemical plants, refineries, makers of consumer and commercial products, industrial facilities, and smaller area sources.

The science of ozone formation, transport, and accumulation is complex. Ground-level ozone is produced and destroyed in a cyclical set of chemical reactions, many of which are sensitive to temperature and sunlight. When ambient temperatures and sunlight levels remain high for several days and the air is relatively stagnant, ozone and its precursors can build up and result in more ozone than typically occurs on a single high-temperature day. Ozone and its precursors can be transported hundreds of miles downwind from precursor emissions, resulting in elevated ozone levels even in areas with low local VOC or NO

emissions.

b. Health Effects of Ozone

This section provides a summary of the health effects associated with exposure to ambient concentrations of ozone.

The information in this section is based on the information and conclusions in the February 2013 Integrated Science Assessment for Ozone (Ozone ISA) prepared by EPA's Office of Research and Development (ORD).

The Ozone ISA concludes that human exposures to ambient concentrations of ozone are associated with a number of adverse health effects and characterizes the weight of evidence for these health effects.

The discussion below highlights the Ozone ISA's conclusions pertaining to health effects associated with both short-term and long-term periods of exposure to ozone.

Human exposure to ozone varies over time due to changes in ambient ozone concentration and because people move between locations which have notable different ozone concentrations. Also, the amount of ozone delivered to the lung is not only influenced by the ambient concentrations but also by the individuals breathing route and rate.

U.S. EPA. Integrated Science Assessment of Ozone and Related Photochemical Oxidants (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-10/076F, 2013. The ISA is available at

http://cfpub.epa.gov/ncea/isa/recordisplay.cfm?deid=247492#Download

The ISA evaluates evidence and draws conclusions on the causal relationship between relevant pollutant exposures and health effects, assigning one of five “weight of evidence” determinations: causal relationship, likely to be a causal relationship, suggestive of a causal relationship, inadequate to infer a causal relationship, and not likely to be a causal relationship. For more information on these levels of evidence, please refer to Table II in the Preamble of the ISA.

For short-term exposure to ozone, the Ozone ISA concludes that respiratory effects, including lung function decrements, pulmonary inflammation, exacerbation of asthma, respiratory-related hospital admissions, and mortality, are causally associated with ozone exposure. It also concludes that cardiovascular effects, including decreased cardiac function and increased vascular disease, and total mortality are likely to be causally associated with short-term exposure to ozone and that evidence is suggestive of a causal relationship between central nervous system effects and short-term exposure to ozone.

For long-term exposure to ozone, the Ozone ISA concludes that respiratory effects, including new onset asthma, pulmonary inflammation and injury, are likely to be a causally related with ozone exposure. The Ozone ISA characterizes the evidence as suggestive of a causal relationship for associations between long-term ozone exposure and cardiovascular effects, reproductive and developmental effects, central nervous system effects and total mortality. The evidence is inadequate to infer a causal relationship between chronic ozone exposure and increased risk of lung cancer.

Finally, interindividual variation in human responses to ozone exposure can result in some groups being at increased risk for detrimental effects in response to exposure. The Ozone ISA identified several groups that are at increased risk for ozone-related health effects. These groups are people with asthma, children and older adults, individuals with reduced intake of certain nutrients (i.e., Vitamins C and E), outdoor workers, and individuals having certain genetic variants related to oxidative metabolism or inflammation. Ozone exposure during childhood can have lasting effects through adulthood. Such effects include altered function of the respiratory and immune systems. Children absorb higher doses (normalized to lung surface area) of ambient ozone, compared to adults, due to their increased time spent outdoors, higher ventilation rates relative to body size, and a tendency to breathe a greater fraction of air through the mouth. Children also have a higher asthma prevalence compared to adults. Additional children's vulnerability and susceptibility factors are listed in Section XII.G.

c. Current and Projected Concentrations of Ozone

Concentrations that exceed the level of the ozone NAAQS occur in many parts of the country, including major population centers such as Atlanta, Baltimore, Chicago, Dallas, Houston, New York, Philadelphia, and Washington, DC. In addition, our modeling without the Tier 3 controls projects that in the future we will continue to have many counties that will have ambient ozone concentrations above the level of the NAAQS (see Section III.C.1). States will need to meet the standard in the 2015-2032 time frame for the 2008 ozone NAAQS. The emission reductions and significant ambient ozone improvements from this rule, which will take effect starting in 2017, will be helpful to states as they work to attain and maintain the ozone NAAQS.

The primary and secondary NAAQS for ozone are 8-hour standards with a level of 0.075 ppm. The most recent revision to the ozone standards was in 2008; the previous 8-hour ozone standards, set in 1997, had a level of 0.08 ppm. In 2004, the U.S. EPA

designated nonattainment areas for the 1997 8-hour ozone NAAQS.

As of December 5, 2013, there were 39 ozone nonattainment areas for the 1997 ozone NAAQS composed of 216 full or partial counties with a total population of over 112 million. Nonattainment designations for the 2008 ozone standard were finalized on April 30, 2012 and May 31, 2012.

As of December 5, 2013, there were 46 ozone nonattainment areas for the 2008 ozone NAAQS, composed of 227 full or partial counties, with a population of over 123 million. As of December 5, 2013, over 135 million people are living in ozone nonattainment areas.

69 FR 23858 (April 30, 2004).

A nonattainment area is defined in the Clean Air Act (CAA) as an area that is violating an ambient standard or is contributing to a nearby area that is violating the standard.

77 FR 30088 (May 21, 2012) and 77 FR 34221 (June 11, 2012).

The 135 million total is calculated by summing, without double counting, the 1997 and 2008 ozone nonattainment populations contained in the Summary Nonattainment Area Population Exposure report (

http://www.epa.gov/oar/oaqps/greenbk/popexp.html

). If there is a population associated with both the 1997 and 2008 nonattainment areas, and they are not the same, then the larger of the two populations is included in the sum.

States with ozone nonattainment areas are required to take action to bring those areas into attainment. The attainment date assigned to an ozone nonattainment area is based on the area's classification. Most ozone nonattainment areas were required to attain the 1997 8-hour ozone NAAQS in the 2007 to 2013 time frame and then to maintain it thereafter.

The attainment dates for areas designated nonattainment for the 2008 8-hour ozone NAAQS are in the 2015 to 2032 timeframe, depending on the severity of the problem in each area. In addition, EPA is currently working on a review of the ozone NAAQS. If EPA revises the ozone standards pursuant to that review, the attainment dates associated with areas designated nonattainment for that NAAQS would be 5 or more years after the final rule is promulgated, depending on the severity of the problem in each area.

The Los Angeles South Coast Air Basin 8-hour ozone nonattainment area and the San Joaquin Valley Air Basin 8-hour ozone nonattainment area are designated as Extreme and will have to attain before June 15, 2024. The Sacramento, Coachella Valley, Western Mojave and Houston 8-hour ozone nonattainment areas are designated as Severe and will have to attain by June 15, 2019.

EPA has already adopted many emission control programs that are expected to reduce ambient ozone levels. As a result of these and other federal, state and local programs, 8-hour ozone levels are expected to improve in the future. However, even with the implementation of all current state and federal regulations, there are projected to be counties violating the ozone NAAQS well into the future. Thus additional federal control programs, such as Tier 3, can assist areas with attainment dates in 2018 and beyond in attaining the NAAQS as expeditiously as practicable and may relieve areas with already stringent local regulations from some of the burden associated with adopting additional local controls.

2. Particulate Matter

a. Background

Particulate matter is a highly complex mixture of solid particles and liquid droplets distributed among numerous atmospheric gases which interact with solid and liquid phases. Particles range in size from those smaller than 1 nanometer (10

−

meter) to over 100 micrometer (μm, or 10

−

meter) in diameter (for reference, a typical strand of human hair is 70 μm in diameter and a grain of salt is about 100 μm). Atmospheric particles can be grouped into several classes according to their aerodynamic and physical sizes, including ultrafine particles (<0.1 μm), accumulation mode or `fine' particles (<1 to 3 μm), and coarse particles (>1 to 3 μm).

For regulatory purposes, fine particles are measured as PM

2.5

and inhalable or thoracic coarse particles are measured as PM

10-2.5

, corresponding to their size (diameter) range in micrometers. The EPA currently has standards that measure PM

2.5

and PM

U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F. Figure 3-1.

Regulatory definitions of PM size fractions, and information on reference and equivalent methods for measuring PM in ambient air, are provided in 40 CFR Parts 50, 53, and 58. With regard to national ambient air quality standards (NAAQS) which provide protection against health and welfare effects, the 24-hour PM

standard provides protection against effects associated with short-term exposure to thoracic coarse particles (i.e., PM

10-2.5

Particles span many sizes and shapes and may consist of hundreds of different chemicals. Particles are emitted directly from sources and are also formed through atmospheric chemical reactions; the former are often referred to as “primary” particles, and the latter as “secondary” particles. Particle concentration and composition varies by time of year and location, and in addition to differences in source emissions, is affected by several weather-related factors, such as temperature, clouds, humidity, and wind. A further layer of complexity comes from particles' ability to shift between solid/liquid and gaseous phases, which is influenced by concentration and meteorology, especially temperature.

Fine particles are produced primarily by combustion processes and by transformations of gaseous emissions (e.g., sulfur oxides (SO

), oxides of nitrogen, and volatile organic compounds (VOC)) in the atmosphere. The chemical and physical properties of PM

2.5

may vary greatly with time, region, meteorology, and source category. Thus, PM

2.5

may include a complex mixture of different components including sulfates, nitrates, organic compounds, elemental carbon and metal compounds. These particles can remain in the atmosphere for days to weeks and travel hundreds to thousands of kilometers.

b. Health Effects of PM

Scientific studies show ambient PM is associated with a broad range of health effects. These health effects are discussed in detail in the December 2009 Integrated Science Assessment for Particulate Matter (PM ISA).

The PM ISA summarizes health effects evidence associated with both short- and long-term exposures to PM

2.5

, PM

10-2.5

, and ultrafine particles. The PM ISA concludes that human exposures to ambient PM

2.5

concentrations are associated with a number of adverse health effects and characterizes the weight of evidence for these health outcomes.

The discussion below highlights the PM ISA's conclusions pertaining to health effects associated with both short- and long-term PM exposures. Further discussion of health effects associated with PM

2.5

can also be found in the rulemaking documents for the most recent review of the PM NAAQS completed in 2012.

43 44

U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F.

The causal framework draws upon the assessment and integration of evidence from across epidemiological, controlled human exposure, and toxicological studies, and the related uncertainties that ultimately influence our understanding of the evidence. This framework employs a five-level hierarchy that classifies the overall weight of evidence and causality using the following categorizations: causal relationship, likely to be causal relationship, suggestive of a causal relationship, inadequate to infer a causal relationship, and not likely to be a causal relationship (U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F, Table 1-3).

78 FR 3086 (January 15, 2013), pages 3103-3104.

77 FR 38890 (June 29, 2012), pages 38906-38911.

The EPA concludes that a causal relationship exists between both long-

and short-term exposures to PM

2.5

and premature mortality and cardiovascular effects and a likely causal relationship exists between long- and short-term PM

2.5

exposures and respiratory effects. Further, there is evidence suggestive of a causal relationship between long-term PM

2.5

exposures and other health effects, including developmental and reproductive effects (e.g., low birth weight, infant mortality) and carcinogenic, mutagenic, and genotoxic effects (e.g., lung cancer mortality).

These causal inferences are based not only on the more expansive epidemiological evidence available in this review but also reflect consideration of important progress that has been made to advance our understanding of a number of potential biologic modes of action or pathways for PM-related cardiovascular and respiratory effects (U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F, chapter 5).

As summarized in the Final PM NAAQS rule, and discussed extensively in the 2009 PM ISA, the scientific evidence available since the completion of the 2006 PM NAAQS review significantly strengthens the link between long- and short-term exposure to PM

2.5

and premature mortality, while providing indications that the magnitude of the PM

2.5

- mortality association with long-term exposures may be larger than previously estimated.

46 47

The strongest evidence comes from recent studies investigating long-term exposure to PM

2.5

and cardiovascular-related mortality. The evidence supporting a causal relationship between long-term PM

2.5

exposure and mortality also includes consideration of new studies that demonstrated an improvement in community health following reductions in ambient fine particles.

78 FR 3103-3104 (January 15, 2013).

U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F, chapter 6 (Section 6.5) and chapter 7 (Section 7.6).

Several studies evaluated in the 2009 PM ISA have examined the association between cardiovascular effects and long-term PM

2.5

exposures in multi-city studies conducted in the U.S. and Europe. While studies were not available in the 2006 PM NAAQS review with regard to long-term exposure and cardiovascular-related morbidity, studies published since then have provided new evidence linking long-term exposure to PM

2.5

with an array of cardiovascular effects such as heart attacks, congestive heart failure, stroke, and mortality. This evidence is coherent with studies of short-term exposure to PM

2.5

that have observed associations with a continuum of effects ranging from subtle changes in indicators of cardiovascular health to serious clinical events, such as increased hospitalizations and emergency department visits due to cardiovascular disease and cardiovascular mortality.

U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F, chapter 2 (section 2.3.1 and 2.3.2) and chapter 6.

As detailed in the 2009 PM ISA, extended analyses of studies available in the 2006 PM NAAQS review as well as epidemiological studies conducted in the U.S. and abroad published since then provide stronger evidence of respiratory-related morbidity effects associated with long-term PM

2.5

exposure. The strongest evidence for respiratory-related effects is from studies that evaluated decrements in lung function growth (in children), increased respiratory symptoms, and asthma development. The strongest evidence from short-term PM

2.5

exposure studies has been observed for increased respiratory-related emergency department visits and hospital admissions for chronic obstructive pulmonary disease (COPD) and respiratory infections.

The body of scientific evidence detailed in the 2009 PM ISA is still limited with respect to associations between long-term PM

2.5

exposures and developmental and reproductive effects as well as cancer, mutagenic, and genotoxic effects, but is somewhat expanded from the 2006 review. The strongest evidence for an association between PM

2.5

and developmental and reproductive effects comes from epidemiological studies of low birth weight and infant mortality, especially due to respiratory causes during the post-neonatal period (i.e., 1 month to 12 months of age).

With regard to cancer effects, “[m]ultiple epidemiologic studies have shown a consistent positive association between PM

2.5

and lung cancer mortality, but studies have generally not reported associations between PM

2.5

and lung cancer incidence.”

U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F. pg 2-13.

Specific groups within the general population are at increased risk for experiencing adverse health effects related to PM exposures.

52 53 54 55

The evidence detailed in the 2009 PM ISA expands our understanding of previously identified at-risk populations and lifestages (i.e., children, older adults, and individuals with pre-existing heart and lung disease) and supports the identification of additional at-risk populations (e.g., persons with lower socioeconomic status, genetic differences). Additionally, there is emerging, though still limited, evidence for additional potentially at-risk populations and lifestages, such as those with diabetes, people who are obese, pregnant women, and the developing fetus.

U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F. Chapter 8 and Chapter 2.

77 FR 38890 (June 29, 2012).

78 FR 3104 (January 15, 2013).

U.S. EPA. (2011). Policy Assessment for the Review of the PM NAAQS. U.S. Environmental Protection Agency, Washington, DC, EPA/452/R-11-003. section 2.2.1.

U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F. Chapter 8 and Chapter 2 (Section 2.4.1).

For PM

10-2.5

, the 2009 PM ISA concluded that available evidence was suggestive of a causal relationship between short-term exposures to PM

10-2.5

and cardiovascular effects (e.g., hospital admissions and ED visits, changes in cardiovascular function), respiratory effects (e.g, ED visits and hospital admissions, increase in markers of pulmonary inflammation), and premature mortality. Data were inadequate to draw conclusions regarding the relationships between long-term exposure to PM

10-2.5

and various health effects.

57 58 59

U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F. Section 2.3.4 and Table 2-6.

78 FR 3167-8 (January 15, 2013).

77 FR 38947-51 (June 29, 2012).

For ultrafine particles, the 2009 PM ISA concluded that the evidence was suggestive of a causal relationship between short-term exposures and cardiovascular effects, including changes in heart rhythm and vasomotor function (the ability of blood vessels to expand and contract). It also concluded that there was evidence suggestive of a causal relationship between short-term exposure to ultrafine particles and respiratory effects, including lung function and pulmonary inflammation,

with limited and inconsistent evidence for increases in ED visits and hospital admissions. Data were inadequate to draw conclusions regarding the relationship between short-term exposure to ultrafine particle and additional health effects including premature mortality as well as long-term exposure to ultrafine particles and all health outcomes evaluated.

60 61

U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F. Section 2.3.5 and Table 2-6.

78 FR 3121 (January 15, 2013).

c. Current and Projected Concentrations of PM

2.5

There are two primary NAAQS for PM

2.5

: an annual standard (12.0 micrograms per cubic meter (μg/m

)) and a 24-hour standard (35 μg/m

), and two secondary NAAQS for PM

2.5

: an annual standard (15.0 μg/m

) and a 24-hour standard (35 μg/m

). The initial PM

2.5

standards were set in 1997 and revisions to the standards were finalized in 2006 and in December 2012. The December 2012 rule revised the level of the primary annual PM

2.5

standard from 15.0 μg/m

to 12.0 μg/m

U.S. EPA (2012). National Ambient Air Quality Standards for Particulate Matter.

http://www.epa.gov/PM/2012/finalrule.pdf

. 78 FR 3164.

There are many areas of the country that are currently in nonattainment for the annual and 24-hour PM

2.5

NAAQS. Our modeling without the Tier 3 controls projects that in the future we will continue to have many areas that will have ambient PM

2.5

concentrations above the level of the NAAQS (see Section III.C.2). States will need to meet the 2006 24-hour standards in the 2015-2019 timeframe and the 2012 primary annual standard in the 2021-2025 timeframe. The emission reductions and improvements in ambient PM

2.5

concentrations from this action, which will take effect starting in 2017, will be helpful to states as they work to attain and maintain the PM

2.5

NAAQS.

In 2005 the EPA designated 39 nonattainment areas for the 1997 PM

2.5

NAAQS.

As of December 5, 2013, over 68 million people lived in the 24 areas that are still designated as nonattainment for the 1997 annual PM

2.5

NAAQS. These PM

2.5

nonattainment areas are comprised of 135 full or partial counties. EPA anticipates making initial area designation decisions for the 2012 primary annual PM

2.5

NAAQS in December 2014, with those designations likely becoming effective in early 2015.

On November 13, 2009 and February 3, 2011, the EPA designated 32 nonattainment areas for the 2006 24-hour PM

2.5

NAAQS.

As of December 5, 2013, 28 of these areas remain designated as nonattainment, and they are composed of 104 full or partial counties with a population of over 65 million. In total, there are currently 39 PM

2.5

nonattainment areas with a population of over 84 million people.

70 FR 19844 (April 14, 2005).

U.S. EPA (2012). Fact Sheet: Implementing the Standards.

http://www.epa.gov/airquality/particlepollution/2012/decfsimp.pdf.

74 FR 58688 (November 13, 2009) and 76 FR 6056 (February 3, 2011).

Data come from Summary Nonattainment Area Population Exposure Report, current as of July 31, 2013 at:

http://www.epa.gov/oar/oaqps/greenbk/popexp.html

and contained in Docket EPA-HQ-OAR-2011-0135.

States with PM

2.5

nonattainment areas will be required to take action to bring those areas into attainment in the future. Designated nonattainment areas not currently attaining the 1997 annual PM

2.5

NAAQS are required to attain the NAAQS by 2015 and will be required to maintain the 1997 annual PM

2.5

NAAQS thereafter. The 2006 24-hour PM

2.5

nonattainment areas are required to attain the 2006 24-hour PM

2.5

NAAQS in the 2015 to 2019 time frame and will be required to maintain the 2006 24-hour PM

2.5

NAAQS thereafter. Areas to be designated nonattainment for the 2012 primary annual PM

2.5

NAAQS will likely be required to attain the 2012 NAAQS in the 2021 to 2025 time frame. The Tier 3 standards finalized here begin taking effect in 2017.

The EPA has already adopted many mobile source emission control programs that are expected to reduce ambient PM concentrations. As a result of these and other federal, state and local programs, the number of areas that fail to meet the PM

2.5

NAAQS in the future is expected to decrease. However, even with the implementation of all current state and federal regulations, there are projected to be counties violating the PM

2.5

NAAQS well into the future. Thus additional federal control programs, such as Tier 3, can assist areas with attainment dates in 2017 and beyond in attaining the NAAQS as expeditiously as practicable and may relieve areas with already stringent local regulations from some of the burden associated with adopting additional local controls.

d. Current Concentrations of PM

In the December 2012 action in which the EPA promulgated the revised primary annual PM

2.5

NAAQS, the EPA also retained the existing primary and secondary 24-hour PM

standards at 150 µg/m

. As of December 5, 2013, over 11 million people live in the 40 areas that are designated as nonattainment for the PM

NAAQS. There are 33 full or partial counties that make up the PM

nonattainment areas.

3. Oxides of Nitrogen and Sulfur

a. Background

Nitrogen dioxide (NO

) is a member of the NO

family of gases. Most NO

is formed in the air through the oxidation of nitric oxide (NO) emitted when fuel is burned at a high temperature. Sulfur dioxide (SO

), a member of the sulfur oxide (SO

) family of gases, is formed from burning fuels containing sulfur (e.g., coal or oil derived), extracting gasoline from oil, or extracting metals from ore.

and NO

and their gas phase oxidation products can dissolve in water droplets and further oxidize to form sulfuric and nitric acid which react with ammonia to form sulfates and nitrates, both of which are important components of ambient PM. The health effects of ambient PM are discussed in Section II.B.2.b of this preamble. NO

and VOC are the two major precursors of ozone. The health effects of ozone are covered in Section II.B.2.1.b.

b. Health Effects of NO

The most recent review of the health effects of oxides of nitrogen completed by the EPA can be found in the 2008 Integrated Science Assessment for Nitrogen Oxides (NO

ISA).

The EPA concluded that the findings of epidemiologic, controlled human exposure, and animal toxicological studies provide evidence that is sufficient to infer a likely causal relationship between respiratory effects and short-term NO

exposure. The 2008 NO

ISA concluded that the strongest evidence for such a relationship comes from epidemiologic studies of respiratory effects including increased respiratory symptoms, emergency department visits, and hospital admissions. Based on both short- and long-term exposure studies, the 2008 NO

ISA concluded that individuals with preexisting pulmonary conditions (e.g., asthma or COPD), children, and older adults are potentially at greater risk of NO

-related respiratory effects. Based on findings from controlled human exposure studies, the 2008 NO

ISA also drew two broad conclusions regarding airway responsiveness following NO

exposure. First, the NO

ISA concluded that NO

exposure may enhance the sensitivity to allergen-induced decrements in lung function and increase the allergen-induced airway inflammatory response following 30-minute exposures of asthmatic adults to NO

concentrations as low as 260 ppb. Second, exposure to NO

has been found to enhance the inherent responsiveness of the airway to subsequent nonspecific challenges in controlled human exposure studies of healthy and asthmatic adults. Small but statistically significant increases in nonspecific airway hyperresponsiveness were reported for asthmatic adults following 30-minute exposures to 200-300 ppb NO

and following 1-hour exposures of asthmatics to 100 ppb NO

. Enhanced airway responsiveness could have important clinical implications for asthmatics since transient increases in airway responsiveness following NO

exposure have the potential to increase symptoms and worsen asthma control. Together, the epidemiologic and experimental data sets form a plausible, consistent, and coherent description of a relationship between NO

exposures and an array of adverse health effects that range from the onset of respiratory symptoms to hospital admission.

U.S. EPA (2008).

Integrated Science Assessment for Oxides of Nitrogen—Health Criteria (Final Report).

EPA/600/R-08/071. Washington, DC: U.S.EPA.

In evaluating a broader range of health effects, the 2008 NO

ISA concluded evidence was “suggestive but not sufficient to infer a causal relationship” between short-term NO

exposure and premature mortality and between long-term NO

exposure and respiratory effects. The latter was based largely on associations observed between long-term NO

exposure and decreases in lung function growth in children. Furthermore, the 2008 NO

ISA concluded that evidence was “inadequate to infer the presence or absence of a causal relationship” between short-term NO

exposure and cardiovascular effects as well as between long-term NO

exposure and cardiovascular effects, reproductive and developmental effects, premature mortality, and cancer.

The conclusions for these health effect categories were informed by uncertainties in the evidence base such as the independent effects of NO

exposure within the broader mixture of traffic-related pollutants, limited evidence from experimental studies, and/or an overall limited literature base.

U.S. EPA (2008).

Integrated Science Assessment for Oxides of Nitrogen—Health Criteria (Final Report).

EPA/600/R-08/071. Washington, DC: U.S.EPA.

c. Health Effects of SO

Information on the health effects of SO

can be found in the 2008 Integrated Science Assessment for Sulfur Oxides (SO

ISA).

Short-term peaks of SO

have long been known to cause adverse respiratory health effects, particularly among individuals with asthma. In addition to those with asthma (both children and adults), potentially sensitive groups include all children and the elderly. During periods of elevated ventilation, asthmatics may experience symptomatic bronchoconstriction within minutes of exposure. Following an extensive evaluation of health evidence from epidemiologic and laboratory studies, the EPA concluded that there is a causal relationship between respiratory health effects and short-term exposure to SO

. Separately, based on an evaluation of the epidemiologic evidence of associations between short-term exposure to SO

and mortality, the EPA concluded that the overall evidence is suggestive of a causal relationship between short-term exposure to SO

and mortality.

U.S. EPA. (2008).

Integrated Science Assessment (ISA) for Sulfur Oxides—Health Criteria (Final Report).

EPA/600/R-08/047F. Washington, DC: U.S. Environmental Protection Agency.

d. Current Concentrations of NO

The EPA most recently completed a review of the primary NAAQS for NO

in January 2010. There are two primary NAAQS for NO

: an annual standard (53 ppb) and a 1-hour standard (100 ppb). The EPA promulgated area designations in the

Federal Register

on February 17, 2012. In this initial round of designations, all areas of the country were designated as “unclassifiable/attainment” for the 2010 NO

NAAQS based on data from the existing air quality monitoring network. The EPA and state agencies are working to establish an expanded network of NO

monitors, expected to be deployed in the 2014-2017 time frame. Once three years of air quality data have been collected from the expanded network, the EPA will be able to evaluate NO

air quality in additional locations.

70 71

U.S. EPA. (2012). Fact Sheet—Air Quality Designations for the 2010 Primary Nitrogen Dioxide (NO

) National Ambient Air Quality Standards.

http://www.epa.gov/airquality/nitrogenoxides/designations/pdfs/20120120FS.pdf.

U.S. Environmental Protection Agency (2013). Revision to Ambient Nitrogen Dioxide Monitoring Requirements. March 7, 2013.

http://www.epa.gov/airquality/nitrogenoxides/pdfs/20130307fr.pdf.

e. Current Concentrations of SO

The EPA most recently completed a review of the primary SO

NAAQS in June 2010. The current primary NAAQS for SO

is a 1-hour standard of 75 ppb. The EPA finalized the initial area designations for 29 nonattainment areas in 16 states in a notice published in the

Federal Register

on August 5, 2013. In this first round of designations, EPA only designated nonattainment areas that were violating the standard based on existing air quality monitoring data provided by the states. The Agency did not have sufficient information to designate any area as “attainment” or make final decisions about areas for which additional modeling or monitoring is needed (78 FR 47191, August 5, 2013). EPA anticipates designating areas for the revised SO

standard in multiple rounds.

4. Carbon Monoxide

Carbon monoxide (CO) is a colorless, odorless gas emitted from combustion processes. Nationally and, particularly in urban areas, the majority of CO emissions to ambient air come from mobile sources.

a. Health Effects of Carbon Monoxide

Information on the health effects of CO can be found in the January 2010 Integrated Science Assessment for Carbon Monoxide (CO ISA).

The CO ISA concludes that ambient concentrations of CO are associated with a number of adverse health effects.

This section provides a summary of the health effects associated with exposure to ambient concentrations of CO.

U.S. EPA, (2010). Integrated Science Assessment for Carbon Monoxide (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-09/019F, 2010. Available at

http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=218686

The ISA evaluates the health evidence associated with different health effects, assigning one of five “weight of evidence” determinations: causal relationship, likely to be a causal relationship, suggestive of a causal relationship, inadequate to infer a causal relationship, and not likely to be a causal relationship. For definitions of these levels of evidence, please refer to Section 1.6 of the ISA.

Personal exposure includes contributions from many sources, and in many different environments. Total personal exposure to CO includes both ambient and nonambient components; and both components may contribute to adverse health effects.

Controlled human exposure studies of subjects with coronary artery disease show a decrease in the time to onset of exercise-induced angina (chest pain) and electrocardiogram changes following CO exposure. In addition, epidemiologic studies show associations between short-term CO exposure and cardiovascular morbidity, particularly increased emergency room visits and hospital admissions for coronary heart

disease (including ischemic heart disease, myocardial infarction, and angina). Some epidemiologic evidence is also available for increased hospital admissions and emergency room visits for congestive heart failure and cardiovascular disease as a whole. The CO ISA concludes that a causal relationship is likely to exist between short-term exposures to CO and cardiovascular morbidity. It also concludes that available data are inadequate to conclude that a causal relationship exists between long-term exposures to CO and cardiovascular morbidity.

Animal studies show various neurological effects with in-utero CO exposure. Controlled human exposure studies report central nervous system and behavioral effects following low-level CO exposures, although the findings have not been consistent across all studies. The CO ISA concludes the evidence is suggestive of a causal relationship with both short- and long-term exposure to CO and central nervous system effects.

A number of studies cited in the CO ISA have evaluated the role of CO exposure in birth outcomes such as preterm birth or cardiac birth defects. The epidemiologic studies provide limited evidence of a CO-induced effect on preterm births and birth defects, with weak evidence for a decrease in birth weight. Animal toxicological studies have found perinatal CO exposure to affect birth weight, as well as other developmental outcomes. The CO ISA concludes the evidence is suggestive of a causal relationship between long-term exposures to CO and developmental effects and birth outcomes.

Epidemiologic studies provide evidence of associations between ambient CO concentrations and respiratory morbidity such as changes in pulmonary function, respiratory symptoms, and hospital admissions. A limited number of epidemiologic studies considered copollutants such as ozone, SO

, and PM in two-pollutant models and found that CO risk estimates were generally robust, although this limited evidence makes it difficult to disentangle effects attributed to CO itself from those of the larger complex air pollution mixture. Controlled human exposure studies have not extensively evaluated the effect of CO on respiratory morbidity. Animal studies at levels of 50-100 ppm CO show preliminary evidence of altered pulmonary vascular remodeling and oxidative injury. The CO ISA concludes that the evidence is suggestive of a causal relationship between short-term CO exposure and respiratory morbidity, and inadequate to conclude that a causal relationship exists between long-term exposure and respiratory morbidity.

Finally, the CO ISA concludes that the epidemiologic evidence is suggestive of a causal relationship between short-term concentrations of CO and mortality. Epidemiologic studies provide evidence of an association between short-term exposure to CO and mortality, but limited evidence is available to evaluate cause-specific mortality outcomes associated with CO exposure. In addition, the attenuation of CO risk estimates which was often observed in copollutant models contributes to the uncertainty as to whether CO is acting alone or as an indicator for other combustion-related pollutants. The CO ISA also concludes that there is not likely to be a causal relationship between relevant long-term exposures to CO and mortality.

b. Current Concentrations of CO

There are two NAAQS for CO: an 8-hour standard (9 ppm) and a 1-hour standard (35 ppm). The primary NAAQS for CO were retained in August 2011. There are currently no CO nonattainment areas; as of September 27, 2010, all CO nonattainment areas were redesignated to maintenance areas. The designations were based on the existing community-wide monitoring network. EPA is making changes to the ambient air monitoring requirements for CO. The new requirements are expected to result in approximately 52 CO monitors operating near roads within 52 urban areas by January 2015 (76 FR 54294, August 31, 2011).

5. Mobile Source Air Toxics

Light-duty vehicle emissions contribute to ambient levels of air toxics known or suspected as human or animal carcinogens, or that have noncancer health effects. The population experiences an elevated risk of cancer and other noncancer health effects from exposure to the class of pollutants known collectively as “air toxics.”

These compounds include, but are not limited to, benzene, 1,3-butadiene, formaldehyde, acetaldehyde, acrolein, polycyclic organic matter, and naphthalene. These compounds were identified as national or regional risk drivers or contributors in the 2005 National-scale Air Toxics Assessment and have significant inventory contributions from mobile sources.

U.S. EPA. (2011) Summary of Results for the 2005 National-Scale Assessment.

www.epa.gov/ttn/atw/nata2005/05pdf/sum_results.pdf

U.S. EPA (2011) 2005 National-Scale Air Toxics Assessment.

http://www.epa.gov/ttn/atw/nata2005

a. Health Effects of Air Toxics

i. Benzene

The EPA's Integrated Risk Information System (IRIS) database lists benzene as a known human carcinogen (causing leukemia) by all routes of exposure, and concludes that exposure is associated with additional health effects, including genetic changes in both humans and animals and increased proliferation of bone marrow cells in mice.

77 78 79

EPA states in its IRIS database that data indicate a causal relationship between benzene exposure and acute lymphocytic leukemia and suggest a relationship between benzene exposure and chronic non-lymphocytic leukemia and chronic lymphocytic leukemia. EPA's IRIS documentation for benzene also lists a range of 2.2 × 10

−6

to 7.8 × 10

−6

as the unit risk estimate (URE) for benzene.

80 81

The International Agency for Research on Carcinogens (IARC) has determined that benzene is a human carcinogen and the U.S. Department of Health and Human Services (DHHS) has characterized benzene as a known human carcinogen.

82 83

U.S. EPA. (2000). Integrated Risk Information System File for Benzene. This material is available electronically at:

http://www.epa.gov/iris/subst/0276.htm

International Agency for Research on Cancer, IARC monographs on the evaluation of carcinogenic risk of chemicals to humans, Volume 29, Some industrial chemicals and dyestuffs, International Agency for Research on Cancer, World Health Organization, Lyon, France 1982.

Irons, R.D.; Stillman, W.S.; Colagiovanni, D.B.; Henry, V.A. (1992). Synergistic action of the benzene metabolite hydroquinone on myelopoietic stimulating activity of granulocyte/macrophage colony-stimulating factor in vitro, Proc. Natl. Acad. Sci. 89:3691-3695.

A unit risk estimate is defined as the increase in the lifetime risk of an individual who is exposed for a lifetime to 1 μg/m3 benzene in air.

U.S. EPA. (2000). Integrated Risk Information System File for Benzene. This material is available electronically at:

http://www.epa.gov/iris/subst/0276.htm

International Agency for Research on Cancer (IARC). (1987). Monographs on the evaluation of carcinogenic risk of chemicals to humans, Volume 29, Supplement 7, Some industrial chemicals and dyestuffs, World Health Organization, Lyon, France.

U.S. Department of Health and Human Services National Toxicology Program. (2011). 12th Report on Carcinogens. Available at:

http://ntp.niehs.nih.gov/?objectid=03C9AF75-E1BF-FF40-DBA9EC0928DF8B15

A number of adverse noncancer health effects including blood disorders, such as preleukemia and aplastic anemia, have also been associated with

long-term exposure to benzene.

84 85

The most sensitive noncancer effect observed in humans, based on current data, is the depression of the absolute lymphocyte count in blood.

86 87

EPA's inhalation reference concentration (RfC) for benzene is 30 μg/m

. The RfC is based on suppressed absolute lymphocyte counts seen in humans under occupational exposure conditions. In addition, recent work, including studies sponsored by the Health Effects Institute, provides evidence that biochemical responses are occurring at lower levels of benzene exposure than previously known.

88 89 90 91

EPA's IRIS program has not yet evaluated these new data. EPA does not currently have an acute reference concentration for benzene. The Agency for Toxic Substances and Disease Registry (ATSDR) Minimal Risk Level (MRL) for acute exposure to benzene is 29 μg/m

for 1-14 days exposure.

92 93

Aksoy, M. (1989). Hematotoxicity and carcinogenicity of benzene. Environ. Health Perspect. 82: 193-197.

Goldstein, B.D. (1988). Benzene toxicity. Occupational medicine. State of the Art Reviews. 3: 541-554.

Rothman, N., G.L. Li, M. Dosemeci, W.E. Bechtold, G.E. Marti, Y.Z. Wang, M. Linet, L.Q. Xi, W. Lu, M.T. Smith, N. Titenko-Holland, L.P. Zhang, W. Blot, S.N. Yin, and R.B. Hayes. (1996). Hematotoxicity among Chinese workers heavily exposed to benzene. Am. J. Ind. Med. 29: 236-246.

U.S. EPA. (2002). Toxicological Review of Benzene (Noncancer Effects). Environmental Protection Agency, Integrated Risk Information System (IRIS), Research and Development, National Center for Environmental Assessment, Washington DC. This material is available electronically at

http://www.epa.gov/iris/subst/0276.htm

Qu, O.; Shore, R.; Li, G.; Jin, X.; Chen, C.L.; Cohen, B.; Melikian, A.; Eastmond, D.; Rappaport, S.; Li, H.; Rupa, D.; Suramaya, R.; Songnian, W.; Huifant, Y.; Meng, M.; Winnik, M.; Kwok, E.; Li, Y.; Mu, R.; Xu, B.; Zhang, X.; Li, K. (2003). HEI Report 115, Validation & Evaluation of Biomarkers in Workers Exposed to Benzene in China.

Qu, Q., R. Shore, G. Li, X. Jin, L.C. Chen, B. Cohen, et al. (2002). Hematological changes among Chinese workers with a broad range of benzene exposures. Am. J. Industr. Med. 42: 275-285.

Lan, Qing, Zhang, L., Li, G., Vermeulen, R., et al. (2004). Hematotoxically in Workers Exposed to Low Levels of Benzene. Science 306: 1774-1776.

Turtletaub, K.W. and Mani, C. (2003). Benzene metabolism in rodents at doses relevant to human exposure from Urban Air. Research Reports Health Effect Inst. Report No.113.

U.S. Agency for Toxic Substances and Disease Registry (ATSDR). (2007). Toxicological profile for benzene. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service.

http://www.atsdr.cdc.gov/ToxProfiles/tp3.pdf

A minimal risk level (MRL) is defined as an estimate of the daily human exposure to a hazardous substance that is likely to be without appreciable risk of adverse noncancer health effects over a specified duration of exposure.

ii. Formaldehyde

In 1991, EPA concluded that formaldehyde is a carcinogen based on nasal tumors in animal bioassays.

An Inhalation Unit Risk for cancer and a Reference Dose for oral noncancer effects were developed by the Agency and posted on the IRIS database. Since that time, the National Toxicology Program (NTP) and International Agency for Research on Cancer (IARC) have concluded that formaldehyde is a known human carcinogen.

95 96 97

EPA. Integrated Risk Information System. Formaldehyde (CASRN 50-00-0)

http://www.epa.gov/iris/subst/0419/htm

National Toxicology Program, U.S. Department of Health and Human Services (HHS), 12th Report on Carcinogens, June 10, 2011.

IARC Monographs on the Evaluation of Carcinogenic Risks to Humans Volume 88 (2006): Formaldehyde, 2-Butoxyethanol and 1-tert-Butoxypropan-2-ol.

IARC Mongraphs on the Evaluation of Carcinogenic Risks to Humans Volume 100F (2012): Formaldehyde.

The conclusions by IARC and NTP reflect the results of epidemiologic research published since 1991 in combination with previous animal, human and mechanistic evidence. Research conducted by the National Cancer Institute reported an increased risk of nasopharyngeal cancer and specific lymphohematopoietic malignancies among workers exposed to formaldehyde.

98 99 100

A National Institute of Occupational Safety and Health study of garment workers also reported increased risk of death due to leukemia among workers exposed to formaldehyde.

101

Extended follow-up of a cohort of British chemical workers did not report evidence of an increase in nasopharyngeal or lymphohematopoietic cancers, but a continuing statistically significant excess in lung cancers was reported.

102

Finally, a study of embalmers reported formaldehyde exposures to be associated with an increased risk of myeloid leukemia but not brain cancer.

103

Hauptmann, M..; Lubin, J. H.; Stewart, P. A.; Hayes, R. B.; Blair, A. 2003. Mortality from lymphohematopoetic malignancies among workers in formaldehyde industries. Journal of the National Cancer Institute 95: 1615-1623.

Hauptmann, M..; Lubin, J. H.; Stewart, P. A.; Hayes, R. B.; Blair, A. 2004. Mortality from solid cancers among workers in formaldehyde industries. American Journal of Epidemiology 159: 1117-1130.

100

Beane Freeman, L. E.; Blair, A.; Lubin, J. H.; Stewart, P. A.; Hayes, R. B.; Hoover, R. N.; Hauptmann, M. 2009. Mortality from lymphohematopoietic malignancies among workers in formaldehyde industries: The National Cancer Institute cohort. J. National Cancer Inst. 101: 751-761.

101

Pinkerton, L. E. 2004. Mortality among a cohort of garment workers exposed to formaldehyde: an update. Occup. Environ. Med. 61: 193-200.

102

Coggon, D, EC Harris, J Poole, KT Palmer. 2003. Extended follow-up of a cohort of British chemical workers exposed to formaldehyde. J National Cancer Inst. 95:1608-1615.

103

Hauptmann, M,; Stewart P. A.; Lubin J. H.; Beane Freeman, L. E.; Hornung, R. W.; Herrick, R. F.; Hoover, R. N.; Fraumeni, J. F.; Hayes, R. B. 2009. Mortality from lymphohematopoietic malignancies and brain cancer among embalmers exposed to formaldehyde. Journal of the National Cancer Institute 101:1696-1708.

Health effects of formaldehyde in addition to cancer were reviewed by the Agency for Toxics Substances and Disease Registry in 1999

104

and supplemented in 2010,

105

and by the World Health Organization.

106

These organizations reviewed the literature concerning effects on the eyes and respiratory system, the primary point of contact for inhaled formaldehyde, including sensory irritation of eyes and respiratory tract, pulmonary function, nasal histopathology, and immune system effects. In addition, research on reproductive and developmental effects and neurological effects were discussed.

104

ATSDR. 1999. Toxicological Profile for Formaldehyde, U.S. Department of Health and Human Services (HHS), July 1999.

105

ATSDR. 2010. Addendum to theToxicological Profile for Formaldehyde. U.S. Department of Health and Human Services (HHS), October 2010.

106

IPCS. 2002. Concise International Chemical Assessment Document 40. Formaldehyde. World Health Organization.

EPA released a draft Toxicological Review of Formaldehyde—Inhalation Assessment through the IRIS program for peer review by the National Research Council (NRC) and public comment in June 2010.

107

The draft assessment reviewed more recent research from animal and human studies on cancer and other health effects. The NRC released their review report in April 2011.

108

The EPA is currently revising the draft assessment in response to this review.

107

EPA (U.S. Environmental Protection Agency). 2010. Toxicological Review of Formaldehyde (CAS No. 50-00-0)—Inhalation Assessment: In Support of Summary Information on the Integrated Risk Information System (IRIS). External Review Draft. EPA/635/R-10/002A. U.S. Environmental Protection Agency, Washington DC [online]. Available:

http://cfpub.epa.gov/ncea/irs_drats/recordisplay.cfm?deid=223614.

108

NRC (National Research Council). 2011. Review of the Environmental Protection Agency's Draft IRIS Assessment of Formaldehyde. Washington DC: National Academies Press.

http://books.nap.edu/openbook.php?record_id=13142

iii. Acetaldehyde

Acetaldehyde is classified in EPA's IRIS database as a probable human carcinogen, based on nasal tumors in rats, and is considered toxic by the inhalation, oral, and intravenous routes.

109

The URE in IRIS for

acetaldehyde is 2.2 × 10

−6

per μg/m

110

Acetaldehyde is reasonably anticipated to be a human carcinogen by the U.S. DHHS in the 12th Report on Carcinogens and is classified as possibly carcinogenic to humans (Group 2B) by the IARC.

111 112

EPA is currently conducting a reassessment of cancer risk from inhalation exposure to acetaldehyde.

109

U.S. EPA (1991). Integrated Risk Information System File of Acetaldehyde. Research and Development, National Center for Environmental Assessment, Washington, DC. This material is available electronically at

http://www.epa.gov/iris/subst/0290.htm

110

U.S. EPA (1991). Integrated Risk Information System File of Acetaldehyde. This material is available electronically at

http://www.epa.gov/iris/subst/0290.htm

111

NTP. (2011). Report on Carcinogens, Twelfth Edition. Research Triangle Park, NC: U.S. Department of Health and Human Services, Public Health Service, National Toxicology Program. 499 pp.

112

International Agency for Research on Cancer (IARC). (1999). Re-evaluation of some organic chemicals, hydrazine, and hydrogen peroxide. IARC Monographs on the Evaluation of Carcinogenic Risk of Chemical to Humans, Vol 71. Lyon, France.

The primary noncancer effects of exposure to acetaldehyde vapors include irritation of the eyes, skin, and respiratory tract.

113

In short-term (4 week) rat studies, degeneration of olfactory epithelium was observed at various concentration levels of acetaldehyde exposure.

114 115

Data from these studies were used by EPA to develop an inhalation reference concentration of 9 μg/m

. Some asthmatics have been shown to be a sensitive subpopulation to decrements in functional expiratory volume (FEV1 test) and bronchoconstriction upon acetaldehyde inhalation.

116

The agency is currently conducting a reassessment of the health hazards from inhalation exposure to acetaldehyde.

113

U.S. EPA (1991). Integrated Risk Information System File of Acetaldehyde. This material is available electronically at

http://www.epa.gov/iris/subst/0290.htm

114

U.S. EPA. (2003). Integrated Risk Information System File of Acrolein. Research and Development, National Center for Environmental Assessment, Washington, DC. This material is available electronically at

http://www.epa.gov/iris/subst/0364.htm

115

Appleman, L.M., R.A. Woutersen, and V.J. Feron. (1982). Inhalation toxicity of acetaldehyde in rats. I. Acute and subacute studies. Toxicology. 23: 293-297.

116

Myou, S.; Fujimura, M.; Nishi K.; Ohka, T.; and Matsuda, T. (1993) Aerosolized acetaldehyde induces histamine-mediated bronchoconstriction in asthmatics. Am. Rev. Respir.Dis.148(4 Pt 1): 940-943.

iv. Acrolein

EPA most recently evaluated the toxicological and health effects literature related to acrolein in 2003 and concluded that the human carcinogenic potential of acrolein could not be determined because the available data were inadequate. No information was available on the carcinogenic effects of acrolein in humans and the animal data provided inadequate evidence of carcinogenicity.

117

The IARC determined in 1995 that acrolein was not classifiable as to its carcinogenicity in humans.

118

117

U.S. EPA. (2003). Integrated Risk Information System File of Acrolein. Research and Development, National Center for Environmental Assessment, Washington, DC. This material is available at

http://www.epa.gov/iris/subst/0364.htm

118

International Agency for Research on Cancer (IARC). (1995). Monographs on the evaluation of carcinogenic risk of ch

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