Risk and Technology Review

for the National Emissions 

Standards for Air Toxics

Presentation for the 

Clean Air Act Advisory Committee (CAAAC)

Economic Incentives and Regulatory 

Innovation Subcommittee

Meeting

January 11, 2011

Point of Contact: Chuck French, U.S. EPA
Outline and Purpose

 Provide brief summary of the Clean Air 

Act requirements for air toxics

 Describe what EPA considers in the 

Risk and Technology Reviews (RTRs) of 

the Emissions Standards

 Provide brief summary of the status 

and schedule of the RTR Program
What Does the Clean Air Act

Require for Air Toxics?

 Identify significant source categories of emissions and 

develop technology-based standards for each category

 These standards are commonly known as Maximum Achievable 

Control Technology, or MACT standards

 Based on performance of the best facilities

 Every 8 years after MACT standards are developed, we 

must perform a “Technology Review” for the MACT 

standards.

 Within 8 years of the MACT standard, we must also 

perform a “Risk Review.”
What is Involved in the 

Technology Review?

 We search for and evaluate advances in practices, 

processes and control technologies.

 If we identify cost-effective approaches to further 

reduce emissions, we revise the MACT standards as 

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reduce emissions, we revise the MACT standards as 

appropriate.

 At the same time that we conduct the technology 

review, we also assess the MACT standard to:

 Address significant unregulated emission points

 Require consistent monitoring and add electronic 

compliance reporting

 Fix administrative requirements that are duplicative or 

inconsistent
What is Involved in the 

Risk Review?

 We assess the remaining risks due to air toxics 

emissions after implementation of the MACT standards, 

and revise the standards, if appropriate.

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 To assess risks we gather data on emissions, processes 

and facilities, and apply models to estimate:

 Cancer risks

 Chronic non-cancer risks

 Acute non-cancer risks
We follow a 2 step approach:

• If the risk of cancer is greater than about 100 in-a-million, risks are 

not “acceptable” and must be reduced irrespective of costs. 

• If risk is less than 100 in-a-million but greater than 1 in-a-million, we assess 

available controls and, if cost-effective, propose action to reduce risks

What is the Decision 

Framework for Cancer Risk?

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“Ample Margin 

of Safety” met,

no action 

needed.

Revise standard, 

if appropriate, to 

achieve an 

“ample margin of 

safety”

Risk “unsafe”, 

action needed

Risk of Cancer

1 in-a-million 100 in-a-million

available controls and, if cost-effective, propose action to reduce risks
What Other Health Factors Do We 

Consider When Making RTR Decisions?

 What is the likelihood of adverse noncancer effects?

 What are the uncertainties and degree of confidence in:

 Emissions and source data?

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 Health data and toxicity values?

 How conservative are the risk estimates?

 What are the overall facility-wide risks?

 Are there disparate demographic risks?

 Are there higher risks for sensitive subpopulations

(e.g., children, subsistence fisher populations)?
What Other Factors Do We Consider 

When Making RTR Decisions?

 How much reduction in risks would each of the 

control options achieve? 

 What are the costs compared to total revenues?

 Impacts to small businesses?

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 Will the controls achieve co-benefit reductions of 

other pollutants (e.g., criteria air pollutants)?

 Are there disadvantages of these controls such as 

increases in other types of pollution

 formation of nitrogen oxides by thermal oxidizers?

 creation of greenhouse gases?

 impacts to other media?
Interaction Between Risk Review 

and Technology Review

 For both the risk and technology reviews, we 

evaluate control options.

 In most cases, we have flexibility in how we 

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 In most cases, we have flexibility in how we 

revise MACT standards.

 After evaluating control options for both reviews, 

we choose options that are cost-effective and 

reduce risks and risk disparities the most.
RTR and Sector Approaches

 RTR is part of EPA multi-pollutant sector approaches.

 RTR is done in parallel to other EPA statutory activities 

such as NSPS and CTGs reviews.

 Combining Combining RTR with multi RTR with multi-pollutant pollutant sector approaches sector approaches 

allows for:

 More informed data collection;

 Aligning of regulatory development timelines;

 Consideration of all pollutants in standards development and all 

emission points; 

 Consolidation of requirements when possible; and

 Consistency in monitoring, testing and reporting requirements.

 This approach does not mean only one rulemaking.

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General RTR Status

 We are required to perform RTR for about 96 standards.

 RTR has been completed for 12 standards.

 Suit filed by Sierra Club on January 14, 2009 because 

EPA missed deadlines for 28 source categories.

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 We have negotiated schedules, but are still waiting for 

final decision by the Court. 

 Current schedule is to complete RTR for most of these 

28 categories over the next 1-3 years.

 For some priority categories (e.g., steel production, and 

oil & gas production), we plan to do the RTRs in the 

context of sector projects.
For More Information

 RTR website:

 http://www.epa.gov/ttn/atw/rrisk/rtrpg.html

Contact Chuck French

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

 Email: French.chuck@epa.gov

 Phone: 919-541-7912

Thank You!