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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

National Emission Standards for 

Hazardous Air Pollutants: Generic

Maximum Achievable Control 

Technology Standards; and 

Manufacture of

Amino/Phenolic Resins; Proposed 

Rule

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Docket No. EPA–HQ–OAR–2012–0133

Via regulations.gov and e-mail

March 10, 2014

COMMENTS OF SIERRA CLUB AND 

CALIFORNIA COMMUNITIES AGAINST TOXICS

Earthjustice submits these comments on behalf of Sierra Club and California 

Communities Against Toxics. EPA’s proposed rule is not strong enough to protect people from 

the health hazards associated with the Generic MACT and Manufacture of Amino/Phenolic 

Resins source category. The record shows that this source has an environmental justice impact 

on African-American and lower income communities. To satisfy the Clean Air Act (CAA or 

Act), EPA must finalize a rule that sets a leak prohibition and establishes up-to-date, stronger 

leak detection and repair requirements and must address and restrict flaring and flared HAP 

emissions. EPA also must not finalize the unlawful and arbitrary affirmative defense. EPA must 

ensure that its risk assessment follows the best available current science to protect the most 

vulnerable and most exposed individuals, including children. 

I. EPA MUST STRENGTHEN THE EMISSION STANDARDS.

EPA refused to strengthen the existing standards to match developments that have 

occurred for many parts of these source categories based purely on its cost-benefit analysis. 

Proposed Rule, 79 Fed. Reg. 1676 (Jan. 9, 2014). Yet EPA’s approach considered only the cost 

per ton of HAP emission reduction, without assessing relevant factors such as: the individual 

HAPs emitted and the impact those HAPs can have at a level below 1 ton; how many people 

would be affected by the potential emission reductions; where they live and if they are in a 

community containing multiple HAP sources, or whether they face a longstanding environmental 

justice impact. EPA also did not consider or address whether the standards would provide any 

“margin of safety” to protect public health, much less whether the margin is “ample.” Thus, EPA 

ignored and violated the plain text of § 112(f)(2) of the Act, 42 U.S.C. § 7412(f)(2). EPA also

did not fulfill the letter or purpose of § 112(d)(6) to ensure that EPA updates the standards when 

developments have occurred that would create stronger protection for public health. EPA’s 
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refusal to strengthen the standards is also arbitrary and capricious. Although it is a positive step

that EPA proposes to update the standards to set MACT floor requirements for the first time 

pursuant to § 112(d)(2)-(3) for certain unregulated emissions, its proposed action would not do 

all that is necessary to fulfill these core legal directives, as discussed in these comments. 

II. EPA MUST REMOVE ALL UNLAWFUL EXEMPTIONS FROM THE 

STANDARDS, INCLUDING BY SETTING LIMITS ON LEAKS AND FLARING.

Commenters urge EPA to follow binding precedent in Sierra Club v. EPA, 551 F.3d 1019 

(D.C. Cir. 2008), and remove all unlawful exemptions from the rules. EPA is legally required to 

remove all unlawful exemptions from the emission standards that have previously existed for 

startup, shutdown, and malfunction (SSM) periods, and not to set any new such exemptions. The 

agency recognizes this is necessary and that it is important for EPA to remove these exemptions 

in this rulemaking. EPA is taking comment on the requirements it must change to comply with 

the D.C. Circuit’s decision.

Commenters support EPA’s recognition of the need to remove all SSM exemptions, 

including to prohibit releases from pressure release devices (PRDs) and require monitoring of 

such devices. 79 Fed. Reg. at 1711, 1713. 

However, EPA has not proposed to remove all such unlawful exemptions. 

1. Equipment leaks are a kind of equipment malfunction. 

EPA may not authorize any such leaks, because this violates Clean Air Act § 302(k) and 

D.C. Circuit precedent. 42 U.S.C. § 7602(k); Sierra Club v. EPA, 551 F.3d 1019 (D.C. Cir. 

2008). Yet EPA has not set any limit on the amount of emissions that can occur during the leak 

detection and leak repair delay periods. And, EPA proposes to define “seal” to allow leaks up to 

500 ppm, which would create another new unlawful exemption. 79 Fed. Reg. at 1715.

Until a leak is detected and a facility repairs it, EPA’s rule allows an unlimited amount of 

HAP emissions to be released. This also violates National Lime Association v. EPA, 233 F.3d 

625 (D.C. Cir. 2000), in which the Court held that EPA must set an emission standard to limit all 

emitted HAPs. If a “seal” regularly allows 500 ppm of emissions to escape, that is also an 

uncontrolled HAP release that violates § 112(d) of the Act and judicial precedent. 

Allowing sources to leak HAP emissions as long as they are below the threshold (e.g., 

10,000 or 500 ppm, as proposed), without setting any limit on these emissions, is equivalent to 

creating an exemption for “out of sight, out of mind” malfunctions. Thus, not setting a limit on 

leaks violates both the plain text and spirit of the Act, § 302(k), and judicial precedent.

In addition, EPA’s proposed definition for a “seal” is actually a new loophole, that would 

exempt leaks from open-ended valves or lines below 500 ppm from the standards. That 
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definition is another type of exemption similar to the SSM exemption the D.C. Circuit found 

unlawful, and EPA should not finalize the definition as proposed. 

Instead of authorizing this unlawful exemption, EPA must prohibit all leaks and require 

the use of leak-less valves and connectors to prevent and control them. EPA also must require 

leak repair to occur, once detected, within the absolute minimum time needed to end each leak. 

All HAP leaks that occur in the intervening time period may cause or contribute to violations of 

the standards. 

2. EPA must prohibit routine flaring, set a cap to limit special flaring, 

ensure its efficiency, and monitor flaring.

EPA is requesting comment on the performance of flares to control HAP emissions. 79 

Fed. Reg. at 1715. But EPA states that it is “not at this time prepared to propose any changes to 

the currently applicable regulations pertaining to the performance of flares in the AMF, PC, and 

APR source categories, but we may revisit the issue in future notices.” Id. EPA is legally 

required to address flares in this rulemaking under § 112(d)(6) and (f)(2). Further, the agency 

must prohibit routine flaring, cap allowable flaring in limited circumstances to prevent 

emergencies, require best practices for use and mandate monitoring of flaring to assure 

compliance and protect communities’ ability to know what is in their air. 

Since these emission standards were set, EPA now has substantial new information on 

flaring, how it works, problems with past flaring, and the impacts it can have. EPA’s 2012 peerreviewed study, noted in the preamble to the proposed rule, and other recent resting has showed

that many flares are not combusting HAPs as efficiently as EPA has long assumed to be the case. 

EPA, Parameters for Properly Designed and Operated Flares, 

www.epa.gov/ttn/atw/flare/2012flaretechreport.pdf.

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 EPA’s enforcement division found the 

same. EPA Enforcement Alert, EPA-325-F-012-002, at 1 (Aug. 2012) (“Through its inspection 

and enforcement programs, EPA has identified many instances where flares have been 

improperly monitored and operated. The consequences are lower combustion efficiency and

potentially significant quantities of excess emissions of volatile organic chemicals, sometimes 

including hazardous air pollutants.”). 

As a result, EPA enforcement cases have led to dramatic reductions in flaring at 

individual facilities. Id.; see, e.g., Marathon and BP Whiting settlements, 

 

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See also “TCEQ 2010 Flare Study”, Texas Commission on Environmental Quality (Aug. 2011), 

http://www.tceq.texas.gov/assets/public/implementation/air/rules/Flare/2010flarestudy/2010-flare-study-finalreport.pdf; “Performance Test of a Steam-Assisted Elevated Flare with Passive FTIR” for Texas City and Detroit, 

Marathon Petroleum Corporation (Sept. 2009 and July 2010), 

http://www.epa.gov/compliance/resources/publications/civil/programs/caa/texascity-report.pdf; 

http://www.epa.gov/compliance/resources/publications/civil/programs/caa/detroit-report.pdf; “PFTIR Tests of 

Steam-Assisted Elevated Flares - Port Arthur”, Flint Hills Resources Port Arthur, LLC (June 2011), 

http://www.epa.gov/compliance/resources/publications/civil/programs/caa/portarthur-report.pdf. 
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http://www.epa.gov/compliance/resources/cases/civil/caa/marathonrefining.html; 

http://www.epa.gov/compliance/resources/cases/civil/caa/bp-whiting.html.

The impact on air quality is significant. “Improper operation of an industrial flare can 

result in hundreds of tons of excess HAP emissions.” EPA, National Enforcement Initiative: 

Cutting Hazardous Air Pollutants, http://www2.epa.gov/enforcement/national-enforcementinitiative-cutting-hazardous-air-pollutants (last updated Feb. 7, 2014). 

EPA must apply all of this new information in this rulemaking. It would be unlawful and 

arbitrary and capricious for the agency not to use the information showing significant new 

information on the combustion efficiency, best practices for the use of flares, and ways to 

prevent, reduce, and monitor flaring -- because they all dramatically reduce the amount of HAPs 

released -- as part of the § 112(d)(6) and § 112(f)(2) rulemakings here. 

First, these changes in flaring use and knowledge about flaring are “developments” 

within the meaning of § 112(d)(6), such that it is EPA is legally required to set stronger 

standards. 42 U.S.C. § 7412(d)(6). The existence of such “developments” makes it “necessary” 

under § 112(d)(6) to revise the existing standards. As EPA has recognized, such “developments” 

include, at least “[a]ny improvements in add-on control technology or other equipment . . . that 

could result in additional emissions reduction,” as well as any new controls, work practices, 

operational procedures, process changes or pollution prevention alternatives. 79 Fed. Reg. at 

1696. By EPA’s own definition, the new data on flaring qualifies as a “development.” Because 

the term “developments” points back to the list of methods to reduce pollution listed in § 

112(d)(2), the new ways to prevent, reduce, improve, and monitor the efficiency of flaring also 

fully qualify as developments that EPA must address here. 42 U.S.C. § 7412(d)(2). Generally in 

its § 112(d)(6) rulemakings, EPA has recognized the need to consider factors listed in § 

112(d)(2), even though it has often refused to set an updated MACT floor as required by § 

112(d)(2)-(3). 

Second, that flares are releasing HAPs into the air, without appropriate § 112(d) limits 

violates National Lime Association. This also violates the Court’s recognition that emission 

standards must apply at all times. When EPA’s standards are allowing HAP releases via badly 

performing flares, this is equivalent to the explicit malfunction exemption that the D.C. Circuit 

and EPA have both recognized as unlawful. 79 Fed. Reg. at 1711 (citing Sierra Club v. EPA). 

These are critical issues for EPA to address in its rulemaking. EPA may not leave it up to the 

public to evaluate the extent to which there are uncontrolled HAP emissions coming from flares 

in this rulemaking. EPA must at least investigate this and ensure that it sets limits on all 

currently uncontrolled HAP emissions from flares, just as it has proposed to do for other 

currently uncontrolled HAP emission points in these source categories. See, e.g., 79 Fed. Reg. at 

1701-03. 
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Third, § 112(f)(2) requires EPA to assess the health risk that remains, with the current 

emission standards in place, and decide whether stronger standards are required to provide an 

“ample margin of safety to protect public health.” 42 U.S.C. § 7412(f)(2); 79 Fed. Reg. at 1680. 

EPA may not fulfill this requirement without accounting for health risk caused by flares -

especially badly performing flares that have even higher emissions of HAPs. Treating the 

emissions and resulting health risk from flares - whether performing normally or performing at 

low efficiency - as zero is indefensible as a scientific matter, and thus both arbitrary and 

unlawful. 

EPA must use the data it has on flaring in order to address this. If EPA believes it does 

not have enough direct information at present, then, at minimum, as EPA has acknowledged, the 

best available science recommends using “defaults,” in such circumstances -- that is, where a risk 

is known to be present but not fully measured. “[Default] options are generic approaches, based 

on general scientific knowledge and policy judgment, that are applied to various elements of the 

risk assessment process when the correct scientific model is unknown or uncertain.” Id.; 79 Fed. 

Reg. at 1693 n.22 (quoting National Academy of Sciences, NRC, Science and Judgment in Risk 

Assessment (1994). EPA has chosen to use such defaults in some aspects of its risk assessment 

in this rulemaking, and must apply a similar approach here. Id. at 1693. The National Academy 

of Sciences has alerted EPA to the problem that it frequently ignores risk -- calling this a 

problem of “missing defaults.” EPA must not allow flaring risk to qualify as such risk. See, e.g., 

NAS, Science and Decisions (2009) at 190-93, 196, 203. EPA must either account for the health 

risk from flares directly using the best available data, or, at least, it must account for this using a 

default. It may not ignore the health risk from flared emissions, as it has proposed to do. Adding 

the health risk from flares is likely to increase the risk metrics EPA considers under § 112(f)(2), 

and require EPA to set stronger standards to protect public health under this provision. 

Finally, although EPA states that it does not currently have source-category specific 

information on flaring, that does not provide an acceptable ground to avoid addressing flaring in 

the current rulemaking. EPA’s own preamble recognizes that flaring is an issue for these source 

categories, or it would not be taking comment and flagging possible future action on this issue. 

EPA has provided no valid basis to distinguish between flares at facilities like refineries and 

chemical plants like the sources under review here. Indeed, such plants often collocated and 

much of the information relevant to flares at refineries is fully relevant to chemical and plastics

plants like those under review using many similar processes. EPA has given no reasoned 

explanation based on the record to avoid applying the important new scientific and technological 

information on flares in this rulemaking. EPA may not lawfully delay action on flares, and doing 

so would be arbitrary. It must apply the best available information it has, collect more, as 

needed, from industry and the states, and ensure that it sets standards in this rulemaking to satisfy 

its Clean Air Act legal duties and protect public health. 

EPA should have sufficient available information to apply the new data on flaring in this 

rulemaking, including from past public submissions on flaring, and from its enforcement division 
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and must investigate the issue in connection with staff who work on the flaring issue there. As 

Dow Chemical recognized, chemical and other companies must adopt the philosophy that “it is 

an unacceptable practice to flare.” Houston 2008, at 18-19 (quoting Steven Krietenstein, Dow 

Chemical Co., Flare Minimization Strategy During Plant Upsets: Freeport (Apr. 12, 2005)). In 

explaining how it is possible to reduce flaring, a Dow Chemical representative stated:

This philosophy had to be accepted at all levels. Management (Leadership) supported the 

project efforts by allowing operations the liberty to slow down the process of upset 

recovery if the efforts would result in less emissions. Under these conditions, production 

rates were third in priority — safety first, flare minimization second, and finally 

production rates. This allowed operations more freedom to think through upset situations 

and take more appropriate action in an effort to reduce flaring. This mindset also opened 

the doors to a larger group to generate further improvements. Even the smallest upset 

events are now managed to reduce flaring.

Id. 

Flares should not be allowed to be routinely used as air control devices, as discussed in 

the 2004 Environmental Integrity Project report.2 As the Houston Report explained, flaring 

causes additional, harmful emissions, which are – like fugitives – likely to be underestimated and 

not taken seriously enough. 

Regular flaring is a problem, not a solution, and so EPA must follow the data and prohibit 

or ensure less reliance on flaring for these source categories.

Flare emissions are generally calculated based on the assumption 

that flaring destroys 98 to 99 percent of the VOCs sent to the flare. 

But, real-world factors, like weather (e.g., high winds) or operating 

conditions (e.g., poor steam ratio) can result in significantly higher 

emissions. Because flares are significant sources of toxic 

emissions, they should be strictly limited. Their sole purpose 

should be treating large volumes of gases that are released as a 

result of emergency facility failures and cannot be recovered. 

Unfortunately, instead of using flares for emergencies, companies 

often use flares as a part of routine operations. In some cases, 

TCEQ has even permitted facilities to flare emissions during 

routine operation. California’s South Coast Air Quality 

Management District found that between 1999 and 2003, only 4 

percent of flaring events could be attributed to emergencies. 

Similarly, EPA investigations found that flaring “frequently occurs 

in routine, non-emergency situations or is used to bypass pollution 

 

2 Envtl. Integrity Project, Gaming the System: How Off-the-Books Industrial Upset Emissions Cheat the Public Out 

of Clean Air 11 (Aug. 2004), http://www.environmentalintegrity.org/news_reports/Report_Gaming_System.php.
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control equipment. This results in unacceptably high releases of 

sulfur dioxide and other noxious pollutants...”3

Commenters believe that the Texas Petrochemicals Houston plant installed a flare gas 

recovery system that reduced its butadiene emissions dramatically, and EPA must investigate 

and consider this tremendous reduction.4The same plant also put in a remote sensing laser 

system. The installation of this laser system demonstrates the value and need for EPA to require 

the use of remote sensing technology as a routine matter for all current sources. As discussed in 

a 2009 news report: 

As a result of enhanced detection by the fence line monitors and 

Texas Petrochemicals’ quicker response to emissions events, 

emissions from the flare decreased 90 percent. Volatile organic 

compounds, contributors to ozone, decreased from 230,000 pounds 

per year in 2004 to 26,000 pounds per year in 2007. Butadiene 

from the flare decreased from an average of 54,000 pounds per 

year to 5,300 pounds per year during the same period.5

EPA must consider these data and collect other similar data to perform the current rulemaking.

Due to the new information EPA now has that flares are less efficient and more harmful 

than previously understood, EPA should consider prohibiting the use of flaring, and requiring 

complete capture through flare gas recovery systems.6 As example problems, a Marathon 2010 

report found that:

 A flare can be operated with greater than 300 BTU/scf vent 

gas net heating value and with acceptable exit gas 

velocities and still be over-steamed.

 Combustion efficiency becomes erratic and generally 

begins to decline sharply once the flame transitions from a 

clean, visible flame to one that is invisible. However, not 

all transparent flames have poor combustion efficiency.

 

3 Houston 2008, supra note 160, at 22 (quoting EPA, Enforcement Alert, Vol. 3, No.9 (Oct. 2000) and citing 

SCAQMD, EVALUATION REPORT ON EMISSIONS FROM FLARING OPERATIONS AT REFINERIES 2, tbl. 1 (2004)). 

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Id. at 17.

5 Env’t News Service, Texas Petrochemicals Must Spend $20M to Clean Houston Air (Apr. 22, 2009) (attached in 

Appendix), available at http://www.ens-newswire.com/ens/apr2009/2009-04-22-092.html.

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See, e.g., Cade et al., Marathon Petroleum Co., Steam Contribution to Combustion Zone Gas in Variable Wind 

Conditions (June 22, 2010); Marathon Petroleum Co., Performance Test of a Steam-Assisted Elevated Flare With 

Passive FTIR, Final Report (May 2010); Marathon Petroleum Co., Performance Test of a Steam‐Assisted Elevated 

Flare with Passive FTIR ‐ Detroit (Nov. 2010); The University of Texas at Austin, The Center for Energy and 

Environmental Resources, TCEQ 2010 Flare Study Final Report at 29 (Aug. 1, 2011) (“The most efficient flare 

operation, as measured by the DRE and CE, for the flare operating conditions tested, was achieved at or near the 

incipient smoke point (ISP). Higher efficiencies could have been achieved with steam or air assist slightly less than 

the ISP assist value but this condition, i.e., a smoking flare, would not have been in compliance with 40 CFR § 

60.18. Therefore, the minimum levels of steam or air assist that comply with the flare manufacturer’s 

recommendations should be used when possible.”).
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 Combustion efficiency declines with increased steam to 

hydrocarbon ratios. The same general trends were observed 

in flare efficiency performance regardless of vent gas 

composition or turndown factors.

 The PFTIR measures a single point within the plume and 

not the composite.

 Variations in chemical composition within the plume itself 

may influence results.7

EPA should also consider requiring sources to develop flare minimization plans, conduct root 

cause analyses of flaring events, and improve flare monitoring, for all of the reasons discussed in 

the 2008 Houston Report.8

As additional examples, from the Houston Report:

California’s Bay Area Air Quality Management District prohibits 

flaring in non-emergencies unless the flaring is consistent with a 

facility’s flare minimization plan, which must include all feasible 

flaring prevention measures. The district found that adding 

compressor capacity and instituting better flare management 

practices resulted in an 85 percent reduction in VOC emissions 

between 2002 and 2005. California’s South Coast Air Quality 

Management District flaring rule requires: (1) improved 

monitoring, (2) flaring only as a result of emergency, shutdown, 

startup, turnaround, or essential operational need, and (3) 

minimization of flare emissions during such events. The district 

estimates that its rule will reduce flare emissions, including VOC 

emissions, by more than 50 percent from 2003 levels, by 2010.9

Like preventing equipment leaks, there is evidence that reducing flaring saves money for the 

industry itself. For example, in 2005, Dow reported that it had saved $2.5 million by capturing 

and rerouting hydrocarbons for reprocessing and use.10

Addressing and Controlling Flaring

At minimum, EPA has and could have no valid basis for not applying the best available 

information on restriction of flaring, such as the California standards, and the agency’s own 

settlements with facilities, to reduce and prevent the use of flaring here under § 112(d)(6) and 

(f)(2). Because flaring creates an unlimited loophole for HAP releases, and has not worked the 

way the agency previously understood to reduce HAP emissions, EPA should prevent the routine 

 

7 Marathon May 2010 Report, id. at 3-45.

8

Id. at 22-23. 

9

Id. at 23.

10 Id. (citing Steven Krietenstein, Dow Chemical Co., Flare Minimization Strategy During Plant Upsets: Freeport 

(April 12, 2005)).
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use of flaring as a control method. Instead, EPA should authorize only limited flaring, with a set 

limit or cap, in circumstances where data show this is essential to prevent accidents or 

explosions, and require necessary monitoring to assure compliance. 

EPA also must set the proper parameters, e.g., on mixing to avoid flame quenching or 

oversteaming, and on heating value. Its own enforcement division has recognized specific 

practices needed to address these problems and EPA must review and apply the experience of 

recent enforcement inspections, evaluations, and settlements in this rulemaking. See, e.g., EPA 

Enforcement Alert, EPA-325-F-012-002, at 3 (Aug. 2012). 

III. EPA MAY NOT PROMULGATE AN AFFIRMATIVE DEFENSE TO CIVIL 

PENALTIES FOR MALFUNCTIONS.

EPA proposes to create an affirmative defense to civil penalties for the standards. 79

Fed. Reg. at 1711 (proposing, e.g., 40 C.F.R. §§ 631.1100(h), 63.1400(l)). The affirmative 

defense provision is unlawful, arbitrary, and harmful and should not be finalized. 

The statute makes clear how the courts are to assess civil penalties, whether a case is 

brought by EPA or a citizen. 42 U.S.C. § 7413(e). Congress plainly intended citizens to be able 

to enforce emission standards under the CAA using the full range of civil enforcement 

mechanisms available to the government, and, in the HAP context, subject only to the limitation 

that government not be “diligently prosecuting” its own civil enforcement action. CAA § 304(a), 

(b)(1)(B), 42 U.S.C. § 7604(a), (b)(1)(B). EPA’s rule proposal, by shifting this careful balance 

and contravening these mandates, violates the CAA. 

The affirmative defense that EPA proposes to allow in case of malfunctions violates the 

Act and goes directly against congressional intent in two ways. First, Congress expressed a clear 

intent that courts, not the agency, are responsible for determining the amount of civil penalties 

available, including by prescribing how judges determine the size of civil penalties whenever 

they are sought, and thus Congress flatly barred EPA from limiting when a court can assess civil 

penalties for a violation of standards. See Chevron, U.S.A., Inc. v. Natural Res. Def. Council, 

Inc., 467 U.S. 837, 842-43 (1984); 42 U.S.C. §§ 7604(a), 7413(e). In this proposal, EPA acts 

outside of its delegated authority to limit civil penalties available in citizen suits or its own 

enforcement actions. See City of Arlington v. FCC, 133 S. Ct. 1863, 1871 n.3 (2013). Second, the 

proposal will impermissibly chill citizen participation, and the ability to win an effective, 

deterrent remedy in CAA enforcement actions. 

The affirmative defense is fatally flawed because EPA does not have the authority to 

decide when civil penalties will not be allowed. The CAA itself spells out the only limits that 

Congress intended to impose on citizens’ ability to seek and recover penalties in enforcement 

suits under CAA § 304, 42 U.S.C. § 7604. See 42 U.S.C. § 7413(e). By attempting to impose 

additional agency-created limits, EPA exceeds its authority.
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Congressional intent on civil penalties is clear—they are a remedy available for 

enforcement by citizen plaintiffs, and the Act gives judges a list of factors they must consider in 

assessing them. As such, EPA cannot interpret the statute to contravene that intent.11 By 

attempting to rewrite these provisions, via regulation, EPA has done just that. 

The CAA grants EPA discretion only with respect to the amount of administrative 

penalties the agency itself imposes, allowing EPA to “compromise, modify, or remit, with or 

without conditions, any administrative penalty which may be imposed under [subsection 

113(d)].” 42 U.S.C. § 7413(d)(2)(B) (emphasis added). There is no similar grant of authority to 

EPA to compromise, modify or limit civil penalties that a court may impose under section 113(e) 

or section 304. The explicit reference to EPA’s ability to modify penalties in one subsection and 

its absence in the other subsection of the same provision can only be understood as an intentional 

decision by Congress that EPA may not contravene by rule.

Congress’s intent to bar EPA from promulgating regulations like the affirmative defense 

is similarly apparent in CAA § 304. CAA § 304(a) gives EPA no functions to perform, thus 

barring it from supplanting district courts’ jurisdiction. 42 U.S.C. § 7604(a). That provision only 

makes EPA the target of citizen suits. See id. By contrast, § 304(b) specifically requires EPA to 

promulgate regulations governing how citizens give notice of citizen suits. Id. § 7604(b). Again,

the express grant of authority to EPA in one subsection and its absence in the other must be 

given effect: EPA has no authority to block district courts from providing the remedy Congress 

specifically made available. 

A facility must not be able to evade civil penalties that apply when the congressionally 

mandated factors in the statute are met.12 See 42 U.S.C. § 7413(e) (listing factors). It would be 

improper for a court to fail to consider these factors, or to override them based on its 

consideration of different factors invented by EPA in the affirmative defense. Further, it would 

be improper for a court to fail to make its own determination of what civil penalties are 

 

11 See Chevron, 467 U.S. at 842-43; see also Barnhart v. Sigmon Coal Co., Inc., 534 U.S. 438, 462 (2002) (“We will 

not alter the text in order to satisfy the policy preferences of the Commissioner.”); North Carolina v. EPA, 531 F.3d 

896, 910 (D.C. Cir. 2008) (“All the policy reasons in the world cannot justify reading a substantive provision out of 

a statute.”).

12 The proposed exemption would also be barred under Chevron step two or found to be arbitrary and capricious. 

Even if there exists some ambiguity, it is unreasonable to construe the statute as permitting EPA to short-circuit the 

consideration of specifically listed factors. See Chevron, 467 U.S. at 843 (explaining that if the statute does not 

answer the question at issue, “the question for the court is whether the agency’s answer is based on a permissible 

construction of the statute”); S. Coast Air Quality Mgmt. Dist. v. EPA, 472 F.3d 882, 895 (D.C. Cir. 2006) (“We 

further hold that EPA’s interpretation of the Act in a manner to maximize its own discretion is unreasonable because 

the clear intent of Congress in enacting the 1990 Amendments was to the contrary.”); see also Gen. Instrument 

Corp. v. F.C.C., 213 F.3d 724, 732 (D.C. Cir. 2000) (explaining that “an arbitrary and capricious claim and a 

Chevron step two argument overlap”); Motor Vehicle Mfrs. Ass’n of U.S., Inc. v. State Farm Mut. Auto. Ins. Co., 

463 U.S. 29, 42-43 (1983) (explaining that agency acts in arbitrary and capricious manner if it fails to consider 

“relevant factors” or “entirely fail[s] to consider an important aspect of the problem”). By “upset[ting] the statutory 

balance struck by Congress,” as discussed above, the affirmative defense is unreasonable under Chevron step two. 

Int’l Alliance of Theatrical & Stage Employees v. N.L.R.B, 334 F.3d 27, 35 (D.C. Cir. 2003).
11

“appropriate” under CAA § 304(a), regardless of whether the conditions invented by EPA in the 

affirmative defense have been satisfied.13 A fortiori it is impermissible for EPA to attempt to 

displace the § 113(e) factors or in any way alter their significance by creating a bar to penalties if 

certain agency-defined considerations are met instead.

The affirmative defense will chill and impede citizen participation in CAA enforcement 

also will be hindered, in violation of citizens’ rights to protect themselves from pollution and in 

direct conflict with congressional intent. The affirmative defense would likely be used on a 

routine basis by polluters seeking to avoid penalties, just as the malfunction exemption was. As 

a result, citizens who seek the assessment of civil penalties against polluters in order to protect 

themselves and achieve the Act’s goals would be forced to engage in time consuming and 

expensive fact-intensive disputes over the applicability of the affirmative defense regardless of 

whether a company has violated its emission standards. Congress did not intend or authorize any

such barriers to enforcement. To the contrary, it provided that Courts may always impose 

penalties on companies that violate their emission standards and required only that courts 

consider the § 113(e) factors in deciding what penalty, if any, to apply. By superimposing an 

additional agency-invented barrier to penalties, the affirmative defense would deter and impede 

citizen enforcement, limiting its effectiveness as a means to prevent and deter violations. As the 

Supreme Court explained: “To the extent that [civil penalties] encourage defendants to 

discontinue current violations and deter them from committing future ones, they afford redress to 

citizen plaintiffs who are injured or threatened with injury as a consequence of ongoing unlawful 

conduct.” Friends of the Earth, Inc. v. Laidlaw Envtl. Servs. (TOC), Inc., 528 U.S. 167, 186 

(2000).14

Thus, the affirmative defense also runs counter to Congressional intent to encourage 

citizen enforcement: (1) the burden it places on citizens makes it less likely that they will enforce 

the Act, see, e.g., Pennsylvania v. Del. Valley Citizens’ Council for Clean Air, 478 U.S. 546, 560 

(1986); and (2) several of the factors at issue in the affirmative defense undercut Congress’s 

intent that citizen suit enforcement should avoid re-delving into “technological or other 

considerations.” Natural Res. Def. Council v. Train, 510 F.2d 692, 723-24 (D.C. Cir. 1974). 

Both result from the technical burden EPA imposes on affected citizens with the affirmative 

defense, and both render the defense impermissible. 

Further, a violation of emission standards that occurs during a malfunction is just as 

much a violation as any other. Allowing only injunctive relief for such violations of emission 

standards is equivalent to providing no remedy for such a violation, except future corrective 

action. This violates sections 302(k) and 112 of the Act, as explained in Sierra Club v. EPA, 551 

 

13 It is also improper for EPA to fail to consider the section 113(e)(1) factors in situations in which it is setting the 

penalty. CAA § 113(e)(1), 42 U.S.C. § 7413(e)(1); see also N.Y. Cross Harbor R.R. v. Surface Transp. Bd., 374 

F.3d 1177, 1184 (D.C. Cir. 2004) (holding that “Board’s failure to balance the competing interests . . . requires” 

vacatur of agency action).

14 S. Rep. No. 101-228, at 373 (1989), reprinted in 1990 U.S.C.C.A.N. 3385, 3756. 
12

F.3d 1019 (D.C. Cir. 2008), because it exempts malfunctions from the primary deterrent 

consequence of having an emission standard established by the Act: paying a penalty for 

violating it. 42 U.S.C. §§ 7413(b), 7604(a). When the affirmative defense is used, all that is left 

is injunctive relief. But injunctive relief only applies prospectively, thereby allowing past 

violations to occur as if there were no emission standard in force. Rather than ensure that the 

emission standards apply continuously, the affirmative defense creates an after-the-fact 

exemption that is equivalent to the exemption that the D.C. Circuit struck down as 

unlawful. Injunctive relief is still available to try to prevent further future violations, but that 

provides no remedy for a past violation. And, if polluting facilities know that they will face no 

civil penalties if they violate the emission standards due to a malfunction, the deterrent power of 

enforcement actions will be severely limited, if not eliminated, even though there is an emission 

standard on the books. By nullifying the Act’s provision for civil penalties for malfunctions, 

EPA has created an exemption from the emission standards for certain past violations that is 

unlawful and arbitrary. 

EPA seeks to rely on a Fifth Circuit case that upheld EPA’s authority to partially approve 

an affirmative defense provision in a state implementation plan (“SIP”). 79 Fed. Reg. at 1711

(citing Luminant Generation Co. v. EPA, 714 F.3d 841 (5th Cir. 2013)). That decision does not 

affirm EPA’s action in all regards or in all jurisdictions. There is good reason why the D.C. 

Circuit should not follow the Fifth Circuit’s decision and why EPA should decide that it will not 

do so in this rulemaking. It is the D.C. Circuit, not the Fifth Circuit, that will have jurisdiction 

over EPA’s final rule in this rulemaking. 

First, Luminant does not even address § 304(a)’s grant of exclusive jurisdiction to district 

courts to hear enforcement cases and apply any civil penalties. Second, the Fifth Circuit’s 

conclusion that § 113(e)(1) is “ambiguous” conflicts with binding D.C. Circuit case law. The 

Fifth Circuit held that § 113 was ambiguous because it “does not discuss whether a state may 

include in its SIP the availability of an affirmative defense against civil penalties for unplanned 

[startup, shutdown, or malfunction] activity,” and thus deferred to EPA. 714 F.3d at 852. That 

analysis assumes that so long as the Act does not explicitly say whether EPA has authority, the 

Act is ambiguous. But such analysis is squarely foreclosed in the D.C. Circuit:

To suggest ... that Chevron step two is implicated any time a statute does not 

expressly negate the existence of a claimed administrative power (i.e. when the 

statute is not written in “thou shalt not” terms), is both flatly unfaithful to the 

principles of administrative law ..., and refuted by precedent.

Rwy. Labor Executives’ Ass’n v. Nat’l Mediation Bd., 29 F.3d 655, 671 (D.C. Cir. 1994) (en 

banc) (emphasis in original); accord, e.g., Shays v. FEC, 414 F.3d 76, 108 (D.C. Cir. 2005); Am. 

Petroleum Inst. v. EPA, 52 F.3d 1113, 1120 (D.C. Cir. 1995); Ethyl Corp. v. EPA, 51 F.3d 1053,

1060 (D.C. Cir. 1995); see also Friends of the Earth v. EPA, 446 F.3d 140, 146 (D.C. Cir. 2006) 
13

(refusing EPA request to follow Second Circuit in rejecting plain meaning of Clean Water Act 

because D.C. Circuit’s case law on statutory interpretation differs from Second Circuit’s).

In addition to these problems, EPA has failed to demonstrate a rational justification for an 

affirmative defense to penalties to be written into the regulations and cause the harm that will 

result. In view of EPA’s prosecutorial discretion and the resulting harm to deterrence, the 

affirmative defense in a regulation is arbitrary and capricious. Importantly, EPA has discretion 

to decide what cases to prosecute, to consider settlements, and to request civil penalties in a caseby-case manner, as long as it acts consistent with the Clean Air Act to protect clean air as its top 

priority, see 42 U.S.C. § 7401. EPA also has the authority to over-file or start prosecuting a 

citizen enforcement matter, if it believes civil penalties should not be sought in a specific case. 

See 42 U.S.C. § 7604(b)(1)(B) (barring citizen suit if EPA or a State has commenced and is 

diligently prosecuting the case). 

In the cases EPA chooses not to bring and which affected citizens bring instead, 

promulgating this affirmative defense is equivalent to giving polluters “get out of jail free” cards 

for serious emission exceedances and MACT violations. Polluters are likely to claim that any 

violation of the standard is due to a malfunction in order to evade the requirements. Allowing 

polluters to evade financial penalties—which are the real teeth of the standards—through this 

type of measure is likely to lead to polluters simply ignoring or factoring potential standard 

violations into their cost of doing business, rather than actually trying to prevent malfunctions 

and violations of the standards as a way to avoid financial losses from the application of 

penalties. EPA has provided no evidence that an affirmative defense for malfunctions would 

serve the purpose of section 112, to protect people from toxic air pollution. Instead, the defense 

contradicts the basic goal of section 112 to protect public health. 

Assuming arguendo that EPA has authority to promulgate any type of affirmative 

defense to penalties for malfunctions, EPA should also promulgate the following provisions:

1. A specific amount of compensatory penalties should apply to each malfunction 

(consistent with the Act). These funds should be dedicated to enforcement, inspections, and 

monitoring in the local community around the specific facility, to create greater assurance that 

such malfunctions will not happen again.

2. A limitation on the affirmative defense so that it cannot be used by a specific 

facility or company more than once within a set period of time, such as 10 years. The 

affirmative defense should become automatically unavailable to a facility that has previously had 

a malfunction within the last 10 years, to ensure that this defense does not swallow the value of 

the standards. 

3. Prompt public reporting and notification requirements for malfunctions, or any 

emission exceedance that occurs of which an operator is aware. Specifically, EPA must require 

that when a facility provides EPA with a notification of a malfunction or emission standard 
14

exceedance under the regulations, this notice will be made publicly available on EPA’s website 

within 7 days. In addition, EPA must promulgate the requirement that when such notification is 

made, the facility must also provide for same-day community notification of the malfunction or 

emission standard exceedance, through an appropriate public forum that is designed to reach 

residents who live near the facility, including but not limited to a notice on the facility’s own 

website (if it has one), a written notice to the local municipality and local school district, a press 

release to the local newspaper, radio, and TV news station that contains information community 

members may need to protect themselves and their families from the additional air pollution. It 

is important that malfunction reports be electronically reported, be made publicly available as 

soon as possible, and include all known information on emissions so that the public can evaluate 

associated health risks. Further, EPA should not allow facilities to wait until the next semiannual 

report to report malfunctions, as it has proposed to do. 

Commenters urge EPA not to adopt an affirmative defense that undermines citizen rights 

and remedies under the Clean Air Act. People living near the facilities in the source categories 

under review are exposed to hazardous air pollution that no one should have to face simply 

because of where they live. Attempting to take away a right granted to citizens by Congress 

through an agency regulation sets a dangerous precedent. EPA must work to expand and protect 

the ability of people harmed by air pollution to seek all appropriate and available forms of relief 

in court. EPA must not retract or weaken citizen rights and remedies, as this proposal does, by 

making it more difficult for people to win meaningful relief from facilities releasing toxic air 

pollution into their communities in cases that EPA chooses not to bring.

IV. EPA MUST REQUIRE THE USE OF REMOTE SENSING DEVICES AND 

CONTINUOUS AIR TOXICS MONITORING.

EPA needs to require remote sensing and continuous air toxics monitoring technologies 

to track and measure emissions. Remote sensing and continuous air toxics monitoring are the 

best ways to accurately measure air toxics emissions from all these facilities. All emissions data 

EPA currently has are primarily estimates subject to significant error in the estimation 

calculations. Remote sensing and continuous monitoring are essential.

The 2008 Houston Report demonstrates the need for improved monitoring. It also 

provides information on technologies available to assess the emissions coming from a chemical 

plant. In particular, it describes the use of example technologies that EPA should require here:

 Differential Absorption Light Detection and Ranging (DIAL)—These 

systems are used extensively in Europe and are being used in Canada. The 

systems use ultraviolet and infrared lasers to measure pollutants, including 

criteria pollutant, light aromatics, methane and total hydrocarbons. The 

DIAL system has been validated in European studies for hydrocarbon 

emissions and its results, while generally found to be conservative, have 

proven more accurate than prior estimates based on emission factors.
15

 Solar Occultation Flux (SOF) — These systems can quantify pollutants, 

much like the DIAL system, and are used in Sweden to monitor whole 

plant emissions. SOF systems are less expensive than DIAL, but they are 

dependent on high sun and steady winds.15

Available technology includes gas chromatography, and laser sensing. EPA must 

consider the CEREX UV Hound. EPA must consider Accusense. EPA has significant 

information on this type of technology and cannot ignore its significant value for the current 

rulemaking. 

EPA must require continuous emission monitoring as it has done for other sources, and 

should consult the Institute of Clean Air Companies regarding the available technology to 

perform continuous monitoring – including for CO, CO2, H2S, NO, NO2, SO2, O2, THC, Hg, 

HCl, and opacity.16 EPA has also recognized that CEMS should be used for lead.17 In addition 

or in the alternative, EPA should also require performance tests at minimum every year, as it has 

required for other source categories.18

V. EPA MUST FINALIZE ADDITIONAL MEASURES TO ASSURE 

COMPLIANCE.

The past history of the SSM exemption and compliance problems for these source 

categories demonstrate the need for strong and more frequent monitoring, testing, and reporting 

requirements described above, and additional enforcement provisions. EPA must implement 

strong enforcement provisions to prevent and remedy emission spikes, malfunctions and other 

violations in a way that will be enforceable by citizens in the Title V permits for these source 

categories.19 Considering that the emissions from these source categories cause disproportionate 

risk in minority and economically disadvantaged communities, additional monitoring and 

stronger enforcement provisions would help provide environmental justice.

For these reasons, first, EPA must write standards that ensure prompt compliance, 

pursuant to the deadlines set by the Act. Section 112 includes strict compliance provisions for 

residual risk standards and all other section 112(d) standards.20 EPA also must ensure that strict 

monitoring and enforcement provisions are part of its standards to enforce the permit condition 

 

15 Houston 2008, supra note 160, at 19. 

16 See, e.g., 40 C.F.R. § 63.1350 (cement kilns – requiring installation of CEMS for mercury, PM, HCl, THC, and 

more frequent monitoring tests for other pollutants); Inst. of Clean Air Companies, Continuous Emissions 

Monitoring Systems (CEMS), http://www.icac.com/i4a/pages/Index.cfm?pageID=3402.

17 See, e.g., 40 C.F.R. § 63.543(l) (“Except as provided in paragraphs (l)(2) or (3) of this section, all new or 

reconstructed sources subject to the requirements under § 63.543 must install, calibrate, maintain, and operate a 

CEMS for measuring lead emissions.”).

18 See, e.g., 40 C.F.R. § 63.543(g)(1), (i) (secondary lead – requiring annual tests to ensure compliance with lead and 

THC standards).

19 See, e.g., NYPIRG & Earth Day Coalition, The Proof Is In the Permit: How to Make Sure a Facility in Your 

Community Gets an Effective Title V Air Pollution Permit (June 19, 2000), available at

http://www.epa.gov/oar/oaqps/permits/partic/proof.html. 

20 42 U.S.C. § 7412(f)(4) (prohibiting non-compliance with a residual risk standard starting 90 days after 

promulgation); id. § 7412(i)(3) (requiring EPA to “provide for compliance as expeditiously as practicable, but in no 

event later than 3 years after the effective date of such standard” with narrow exceptions). 
16

requirements of the Act. The Clean Air Act requires permits to contain “conditions as are 

necessary to assure compliance with applicable requirements of [the Act].”21 40 C.F.R. Part 70 

adds detail to this requirement. 40 C.F.R. § 70.6(a)(3) requires “monitoring sufficient to yield 

reliable data from the relevant time period that are representative of the source’s compliance.” 

Section 70.6(c)(1) requires all Part 70 permits to contain “testing, monitoring, reporting, and 

recordkeeping requirements sufficient to assure compliance with the terms and conditions of the 

permit.”22 EPA should fully review the monitoring requirements it has proposed and ensure that 

they are stringent enough so that EPA, states, and citizens can easily assess whether a facility is 

in full compliance with the standards within a short period of time of any violation. 

Second, EPA must promulgate specific public reporting and notification requirements for 

malfunctions, or any emission exceedance that occurs. EPA proposes to require malfunction 

reporting to EPA as part of a periodic compliance report, which may occur as long as 45 days

after the alleged malfunction, if a source intends to take advantage of an affirmative defense.23

EPA should require this reporting regardless whether a facility intends to try to take advantage of 

an affirmative defense (which EPA should not authorize). However, even EPA’s proposed 

reporting requirement provides only delayed, after-the-fact information to the community. For 

people near the facility, a written report as long as 45 days later, is too late to find out about 

emission spikes and alleged malfunctions that may have threatened public health. 

EPA must require telephone reporting by the facility no later than 24 hours after the 

malfunction or exceedance. EPA must require that when a facility provides EPA with telephone 

notification of a malfunction or emission exceedance under the regulations, this notice will be 

made publicly available on EPA’s website and through ECHO within 24 hours. 

EPA should require that the EPA Administrator provide this information to its Regional 

office within 24 hours of receiving notification, and direct the Regional office to notify the local 

community on the Internet, by direct communication, and through all available means. 

In addition, EPA must promulgate the requirement that when such notification is made, 

the facility must also provide for community notification of the malfunction or emission standard 

exceedance within 24 hours, through an appropriate public forum that is designed to reach 

residents who live near the facility, including but not limited to a notice on the facility’s own 

website (if it has one), a written notice to the local municipality and local school district and a 

press release to the local newspaper, radio, and TV news station that contains any information 

community members may need to try to protect themselves and their families from the additional 

air pollution. Commenters support EPA’s proposal to require reporting of malfunctions, but it is 

important that this information be reported more quickly, be electronically reported, be made 

publicly available, and include all known information on emissions so that the public can 

evaluate associated health risks.

EPA should also require a written report to be submitted within 7 days, and use the same 

distribution method as outlined above, including publication on ECHO, EPA’s Regional website, 

 

21 42 U.S.C. § 7661c(a).

22 40 C.F.R. § 70.6(a)(3). 

23 79 Fed. Reg. at 1720 (proposing 40 C.F.R. § 63.1100(h)(2)).
17

and distribution to active local community members who are interested (such as through setting 

up an email list, a local listserv, Twitter, and other media). 

In the written report, EPA should require the facility to report: (1) the nature of the event; 

(2) the duration of the event; (3) estimate of emissions released during the event; and (4) a 

description and timing of corrective actions that were taken and any planned to be taken. 

Fourth and very importantly, reporting of malfunctions or other exceedances is not 

enough to protect the most exposed people from the HAP emissions from the source categories 

under review in this rulemaking. EPA also must promulgate additional requirements that apply 

in the event of a malfunction or violation of the numerical emission standards. The Clean Air 

Act requires continuous compliance with the emission standards.24 The data from Texas 

demonstrate significant spikes in emissions and an unusual record of exceedances and violations 

that EPA cannot ignore for the chemical production industry. EPA must take action to protect 

local communities from health risk caused by these sources. Facilities must not be able to emit 

in an unlimited manner for an unlimited period of time.

In addition to requiring reporting of exceedances and malfunctions as described above, 

when such an event occurs:

1. EPA must require automatic shut-off of the malfunctioning equipment or process 

for the time needed to take corrective action whenever an exceedance or malfunction occurs.

2. EPA must assign responsibility and liability to the plant manager or a high-up 

staff member which allows only that person to restart the equipment or process. 

3. EPA must require specific corrective measures to be taken immediately to remedy 

and prevent recurrence of the malfunction or violation. 

4. For a facility that has had 1 or more malfunction, exceedance, or other violation 

incident in the prior month, written authorization by EPA must be required to restart equipment 

or processes. EPA should only authorize restart after making a public determination that 

provides information on the corrective measures that EPA is requiring. EPA should release this 

public determination on the Internet and require its Regional office to communicate this 

determination to all interested members of the public, including local community representatives. 

5. If a facility has more than 4 exceedances or malfunctions during the same quarter, 

then EPA must require automatic shut down of the operation for a period of time needed to 

conduct and publish a full investigation and ensure systematic correction of the problem/s.

6. EPA should create a community complaint mechanism in the standards that 

ensures that citizen complaints of clouds, plumes, exceedances, odors, other air pollution 

incidents or health concerns receive an immediate response, in which EPA commits to initiate an 

investigation and provide a publicly available report of the result of the investigation, including 

whether it leads to an enforcement outcome from EPA’s enforcement division within 7 days. 

 

24 See Sierra Club v. EPA, 551 F.3d 1019, 1028 (D.C. Cir. 2008).
18

VI. EPA MUST FOLLOW THE BEST AVAILABLE SCIENCE TO ASSESS AND 

REDUCE HEALTH RISK FOR EXPOSED COMMUNITY MEMBERS AS 

REQUIRED BY § 112(F)(2).

Although EPA states that it is taking a conservative, health-protective approach, and it 

has made some progress in recent years, the agency still lags well behind the best available, 

current science to address the real-world health risk for the individual most exposed to the 

current source categories. EPA must finally act to apply this science in the current rulemaking 

and all other health risk rulemakings under the Clean Air Act under § 112(f)(2). 

In particular, EPA has no valid excuse to avoid following the recommendations of the 

National Academy of Sciences and its own Science Advisory Board on the below-discussed key 

issues that affect the most-exposed and most vulnerable populations, especially children and 

environmental justice communities. 

EPA must consider the science, and update and strengthen its risk assessment in, at least, 

each of the following ways before finalizing the rule: 

 Account for individual-level vulnerability in this risk assessment by better 

incorporating the vulnerability of children, early-life exposures, and the developing 

fetus into risk assessment methods:

 Account for increased susceptibility by using age-dependent 

adjustment factors for all carcinogens, not just known mutagens.

 Pre-natal susceptibility: Account for increased susceptibility by using a 

pre-natal adjustment factor for all carcinogens of at least 10X.

 For chronic non-cancer risk, consult and apply child-specific reference 

values (such as those created by California EPA scientists), where 

available.

 If child-specific reference values are unavailable, consult science on 

early exposure impacts, and use an additional default factor of at least 

10X.

 Account for vulnerability due to residence in a community that is highly exposed, by 

including factors to account for increased vulnerability based on demographic 

differences, as part of the risk assessment. EPA also must fully integrate the findings 

of its environmental justice analyses into this risk assessment and rulemaking, and set 

stronger pollution limits to provide environmental justice.

 Assess the cumulative burden of exposures to multiple pollutants and sources via 

multiple pathways:

 Assess and aggregate exposure from multiple pathways – including by 

adding inhalation and non-inhalation-based cancer risks.

 Include the interaction of multiple pollutants.

 Account for exposure to multiple sources. Until EPA has a specific 

mechanism for estimating total exposures, a default or uncertainty 

factor of at least 10X should be used to provide overburdened 
19

communities with the protection they need now. 

 Account for cumulative impacts of multiple exposures and vulnerabilities by shifting 

the level of risk which triggers policy action. 

 Reduce EPA’s benchmark of what it considers acceptable lifetime cancer risk 

instead of relying on the outdated upper limit of 100-in-a-million. 

 Use a Margin of Exposure (MOE) framework for non-cancer impacts and 

adjust the target MOE according to known vulnerability factors.

 In the face of increasing evidence calling into question the assumption of a safe or 

acceptable level of exposure, EPA should also consider changing its approach to risk 

assessment to support reducing risks to the lowest possible level, to protect public 

health, rather than suggesting that there is always a safe or acceptable level. As EPA 

itself has recognized, there are many uncertainties suggesting its risk assessment is an 

underestimate and only addresses part of the picture.

Each of the above-listed risk issues is a factor that is relevant to EPA’s risk assessment, 

on which there is science that EPA should apply, and which EPA is legally required to address in 

order to fulfill its duty to assess health risk and provide the “ample margin of safety to protect 

public health” under § 112(f)(2). EPA has provided no reasoned explanation for not applying the 

current science to address these risk factors. And, as shown in the additional information on 

these issues summarized below, EPA can have no valid basis for ignoring the science from 

experts such as the National Academy of Sciences, Science Advisory Board, and other expert 

regulators, such as California EPA’s Office of Health Hazard Assessment (OEHHA). EPA must 

direct its scientists to apply each of the scientific bases and tools currently available that EPA is 

ignoring and must address. 

It would be both unlawful under § 112(f)(2) for EPA to ignore the health risks outlined 

above, and arbitrary and capricious for EPA to avoid applying the best available science here. It 

also would be unacceptable and unfair for EPA to ignore the current scientific and regulatory 

tools available for communities bombarded by toxic air pollution from the current source 

categories and many others. 

If EPA wishes to act on its stated commitment to environmental justice, it will finally 

start using the science available now to address these impacts and risks, while also working to 

continue to update its risk assessment approaches. 

A. Account for individual-level vulnerability in risk assessment by better 

incorporating the vulnerability of children, early-life exposures, and the 

developing fetus into risk assessment methods.

The National Academy of Sciences (“NAS”) reports and other new scientific and policy 

developments direct that EPA must better account for vulnerability and variability. See

Appendix B-C. In particular, the science is now clear that “children are not ‘little adults’” when 
20

it comes to toxic chemicals.25 They are both susceptible to greater harm from exposure to toxic 

chemicals, because they are still growing and developing, and they are exposed to such 

chemicals at a greater rate than adults because of age-specific behaviors and physiological 

characteristics. Second, EPA must also better account for other types of human variability 

because some people exposed to the same amount of a pollutant experience greater health risk 

due to other factors, such as genetics and baseline health status. Socioeconomic status has been 

shown to act as a proxy for other types of human variability to chemical risk that EPA has not 

adequately addressed in its risk assessment. 

This section discusses key ways in which EPA must better address both the greater risk to 

children (including from early-in-life exposure to toxic chemicals), and other important types of 

human variability. Appendix B and C of this document summarize the significant body of 

scientific and policy developments on children’s health and environmental justice which 

illustrates the need for updates to EPA’s risk assessment approach. 

1. Children’s Risk and Early-Life Exposures 

a. Account for increased early life susceptibility by using agedependent adjustment factors for all carcinogens.

EPA’s cancer risk assessment in this rulemaking does not adequately account for earlylife exposure or the greater risk to and susceptibility of children. For cancer risk assessment, 

EPA should follow the science and account for increased early-life susceptibility by applying 

age-dependent adjustment factors for all carcinogens emitted by a source category. 

EPA has restricted its application of age-dependent adjustment factors, as discussed in 

the 2005 Guidelines and Supplemental Guidance for Assessing Susceptibility from Early-Life 

Exposure to Carcinogens, to those hazardous air pollutants (“HAPs”) included in EPA’s list of 

carcinogens that act by a mutagenic mode of action.26 It therefore has not applied age-dependent 

adjustment factors to assess cancer risk from all of the carcinogens emitted by a source category. 

The NAS recognized this as a “missing” default in EPA’s approach that it should address and 

account for.27 

Instead of taking the approach of the 2005 Guidelines and Supplemental Guidance to 

limit the use of age-dependent adjustment factors to only some carcinogens, EPA must follow 

 

25 National Research Council, “Pesticides in the Diets of Infants and Children” at 3 (1993).

26 See EPA, “Guidelines for Carcinogen Risk Assessment,” EPA/630/P-03/001F, at 1-19 to 1-20 (Mar. 2005), 

http://www.epa.gov/raf/publications/pdfs/CANCER_GUIDELINES_FINAL_3-25-05.PDF; EPA, “Supplemental 

Guidance for Assessing Susceptibility from Early-Life Exposure to Carcinogens,” EPA/630/R-03/003F (2005), 

http://www.epa.gov/raf/publications/pdfs/childrens_supplement_final.pdf; see, e.g., EPA OAQPS, “National 

Emissions Standards for Hazardous Air Pollutants: Secondary Lead Smelters, Summary of Public Comments and 

Responses,” at 72-73 (11-14-11), EPA-HQ-OAR-2011-0344-0167.

27 NAS 2009 at 196 (Tbl. 6-3 - Examples of “Missing” Defaults in EPA “Default” Dose-Response Assessments).
21

the lead of OEHHA by using age-dependent adjustment factors for all carcinogens.28 Because 

OEHHA has provided robust scientific support for this approach, using these factors to assess 

cancer risk for all carcinogens would be consistent with the NAS recommendations. As the NAS 

explained: “EPA needs methods for explicitly considering in cancer risk assessment . . .

chemicals that do not meet the threshold of evidence that the agency is considering for judging 

whether a chemical has a mutagenic mode of action . . . . Special attention should be given to 

hormonally active compounds and genotoxic chemicals that do not meet the threshold of 

evidence requirements.”29

The 2005 Guidelines recognized that updates would be needed if more data become 

available.30 Now that such data are available, including from the NAS and OEHHA, the agency 

must update its approach promptly. EPA should immediately implement the OEHHA agedependent adjustment factors for all carcinogens, and EPA should also update the 2005 

Guidelines to fully reflect current science as described in OEHHA’s 2009 review of the scientific 

literature on increased susceptibility to carcinogens from early life exposures.31 

b. Pre-natal susceptibility: Account for increased susceptibility to 

pre-natal exposures by using pre-natal adjustment factors for 

all carcinogens.

EPA’s risk assessment also does not take into account increased susceptibility to 

carcinogens due to pre-natal exposures. The 2005 Supplemental Guidance recognized the 

scientific findings of increased susceptibility to carcinogens resulting from pre-natal exposure, 

but did not develop adjustment factors to account for increased cancer risk resulting from prenatal exposures.32

 For example, EPA recognized that “[e]xposures that are of concern extend 

from conception through adolescence and also include pre-conception exposures of both 

parents.”33 The NAS identified the lack of accounting for “in utero periods” of exposure as a 

major omission in EPA’s 2005 cancer guidelines.34

OEHHA conducted its own review of the scientific literature to account for pre-natal 

 

28 Cal. EPA, OEHHA, “Technical Support Document for Cancer Potency Factors: Methodologies for Derivation, 

Listing of Available Values, and Adjustments to Allow for Early Life Stage Exposures” 3-4, 50-51 (May 2009), 

http://www.oehha.ca.gov/air/hot_spots/2009/TSDCancerPotency.pdf, and 

http://oehha.ca.gov/air/hot_spots/tsd052909.html.

29 NAS 2009 at 112 (ch. 4) (describing the fact that “in utero periods and nonmutagenic chemicals were not 

covered” by EPA’s 2005 guidelines, as significant omissions).

30 See EPA, 2005 Supp. Guidance at 21, 31 (“EPA expects to expand this Supplemental Guidance to specifically 

address modes of action other than mutagenicity when sufficient data are available and analyzed.”).

31 Cal. EPA, OEHHA, TSD for Cancer Potency Factors, supra note 28.

32 EPA, 2005 Supp. Guidance at 4-5, 14 & tbl. 1a (A-1) (discussing research on human and animal cancer risks 

from prenatal exposure).

33 EPA 2005 Guidelines for Carcinogen Risk Assessment, EPA/630/P-03/001F, at 1-16. 

34 NAS 2009 at 112-13; see also id. at 112, 196 (noting that it is a “missing” default that EPA recognizes in utero 

carcinogenic activity, but fails to take account of it or calculate any risk for it as “EPA treats the prenatal period as 

devoid of sensitivity to carcinogenicity”).
22

susceptibility and exposures, which EPA should also consult and use.35 It has also developed 

methods and adjustment factors to account for pre-natal susceptibility and exposures that EPA 

should use.36 In its new risk assessment guidelines, OEHHA includes procedures for exposure 

assessment during fetal development, which EPA should evaluate.37 OEHHA specifically 

discusses the use of a 10X adjustment factor for cancer risk due to pre-natal to age 2 exposures, 

and EPA should consider using at least this same factor.38 

EPA should consult the science OEHHA has used to develop this well-supported factor, 

and should then use at least a 10X adjustment factor for all carcinogens to assess health risk due 

to pre-natal exposure. 

c. For chronic non-cancer risk, consult and apply child-specific 

reference values, where available. 

Most of EPA’s IRIS toxicity threshold values (reference concentrations and reference 

doses) used for chronic non-cancer risk assessment do not incorporate the latest science on 

increased susceptibility of children.39 EPA needs to account for early exposure and the greater 

risk to and susceptibility of children in its risk assessment, including for cadmium and lead, 

which it has recognized are emitted by the source categories under review in this rulemaking. 

OEHHA child-specific health values include reference doses for cadmium, chlordane, 

heptachlor, manganese, methoxychlor, nickel, and pentachlorophenol, and a benchmark for lead. 

A full list, with links to each scientific determination document, is available here: OEHHA, 

Table of all child-chRDs Finalized to Date (last updated 06/22/09), 

http://oehha.ca.gov/public_info/public/kids/chrdtable.html. OEHHA has generated these childspecific reference values based on the latest science to take into account children’s greater 

exposure and greater vulnerability. 

At least until the IRIS values fully account for the increased risk caused by early-life 

 

35 See Cal. EPA, OEHHA, “Technical Support,” supra note 28, App. J: “In Utero and Early Life Susceptibility to 

Carcinogens: The Derivation of Age-at-Exposure Sensitivity Measures” – conducted by OEHHA’s Reproductive 

and Cancer Hazard Assessment Branch,” .http://oehha.ca.gov/air/hot_spots/2009/AppendixJEarly.pdf.

36 Id. App. J at 7-8 & tbl. 1.

37 See Cal. EPA, OEHHA, Air Toxics Hot Spots Program Risk Assessment Guidelines, Technical Support 

Document for Exposure Assessment and Stochastic Analysis, Scientific Panel Review Draft at 1-6 to 1-7 (Feb. 

2012) (“OEHHA 2012 Guidelines”).

38 See id.

39 OEHHA has explained why child-specific reference doses or values are needed and provided a list of chemicals. 

See, e.g., Cal. EPA, OEHHA, “Prioritization of Toxic Air Contaminants - Children’s Environmental Health 

Protection Act” (Oct. 2001), 

http://oehha.ca.gov/air/toxic_contaminants/pdf_zip/SB25%20TAC%20prioritization.pdf; Cal. EPA, OEHHA, 

“Development of Health Criteria for School Site Risk Assessment Pursuant to Health and Safety Code 901(g): 

Identification of Potential Chemical Contaminants of Concern at California School Sites, Final Report” (June 2002), 

http://oehha.ca.gov/public_info/public/kids/pdf/ChildHealthreport60702.pdf.
23

exposure to an emitted pollutant, EPA should use the OEHHA child-specific reference doses or 

benchmarks available to assess chronic non-cancer health risk from ingestion for certain 

pollutants. EPA should also assess such risk from inhalation by using standard methods to 

translate these values into child-specific reference concentrations to assess inhalation-based risk. 

d. Where child-specific reference values are unavailable, consult 

science on early exposure impacts and use an additional 

default or uncertainty factor.

The increased susceptibility of children, while known to exist, has not been quantified for 

many toxic chemicals. Until EPA has child-specific or child-based reference values available for 

a given pollutant, EPA should apply a default or uncertainty factor of at least 10 to account for 

increased risk from early-life exposures for non-cancer risk assessment. 

This would be consistent with the NAS recommendation on the need for EPA to use 

default factors to account for greater risk,40 with the science developed and considered by 

OEHHA, and with the 10X factor enacted by Congress in the Food Quality Protection Act. 

Specifically, as the SAB report explained:

California EPA/OEHHA has determined that inhalation dosimetry 

for children is sufficiently different from adults to warrant a full 

10-fold intra-individual pharmacokinetic uncertainty factor (i.e., an 

extra 3-fold PK uncertainty for children relative to the IRIS 

method) as a default approach. In setting non-cancer reference 

exposure levels (RELs), Cal EPA/OEHHA also considers that 

children may be outliers in terms of chemical susceptibility and on 

a case-specific basis adds a children’s pharmacodynamic factor of 

3-fold, making the inhalation risk for children as much as 10 times 

greater than adults.

41

In addition, Congress has recognized this science in its unanimous vote on toxics 

legislation passed in 1996 – the Food Quality Protection Act (“FQPA”) – in which Congress 

found the need to use and enacted a Ten-fold Margin of Safety, or “10X factor.” Specifically, 

the Act provides that “an additional tenfold margin of safety for the pesticide chemical residue 

and other sources of exposure shall be applied for infants and children to take into account 

potential pre- and post-natal toxicity and completeness of the data with respect to exposure and 

toxicity to infants and children.”42 Congress’s recognition of the need to use this default factor 

provides a model that EPA should consider and incorporate into this and other residual risk 

assessments. It would be appropriate and within EPA’s authority under the Clean Air Act 

 

40 NAS 2009 at 190-93, 203.

41 SAB May 2010 at 34 (May 2010) (citing Cal. EPA, OEHHA, “Technical Support,” supra.) 

42 21 U.S.C. § 346a(b)(2)(C) (requiring that, in establishing, modifying, leaving in effect, or revoking a tolerance or 

exemption for a pesticide chemical residue, “for purposes of clause (ii)(I) an additional tenfold margin of safety for 

the pesticide chemical residue and other sources of exposure shall be applied” to protect infants and children).
24

section 112(f)(2) to determine that EPA must similarly use a children’s ten-fold margin of safety 

factor here, consistent with the Clean Air Act’s “margin of safety” requirement.43 In doing so, 

EPA may rely directly on the science itself, and also on the unanimous guidance from Congress, 

provided in the FQPA, that the existing evidence of increased harm requires significant action to 

protect children from toxic exposure. 

Further, the child-specific reference doses that OEHHA has created for some pollutants 

provide support for the use of an additional Ten-fold Margin of Safety Factor. EPA’s current 

reference values are generally one order of magnitude less protective (i.e., larger) than the values 

that California has recognized as needed to protect children, based on the currently available 

science and a specific assessment of research relevant to early life exposures, as shown in the 

chart attached as Appendix D.

2. Include factors to account for increased vulnerability based on 

demographic differences, as part of the risk assessment. 

EPA found disparity in the risks created by the source categories under review, with more 

impact falling on African-American and lower income communities. 

The NAS report identified significant flaws in EPA’s assessment of individual variability 

in risk assessments that could result in significant underestimation of risk. In particular, EPA 

must fully account for the fact that people can be more vulnerable to toxic pollution due to 

various physiological, societal, demographic, and exposure history differences and can therefore 

experience greater health risk from the same amount of a toxic chemical exposure.44 As the 

NAS has observed, performing risk assessment that is meaningful for communities that already 

face a significant amount of pollution and communities concerned about environmental justice 

“requires an ability to evaluate multiple agents or stressors simultaneously—to consider 

exposures not in isolation but in the context of other community exposures and risk factors.”45 

Addressing this issue is particularly important for EPA because of the need to consider and 

address environmental justice as mandated by Exec. Order 12898.

Communities that have minority and lower income populations and communities with 

higher than average levels of cancer, respiratory, and other health problems, as well as a lack of 

 

43 42 U.S.C. § 7412(f)(2). 

44 See, e.g., NAS 2009 at 135-39, 145-51 (explaining that “[h]ow the population responds to chemical insults 

depends on individual responses, which vary among individuals”; and “[i]f the sensitive people constitute a distinct 

group either because of their numbers or because of identifiable characteristics—such as ethnicity, genetic 

polymorphism, functional or health status, or disease—they should be considered for separate treatment in the 

overall risk assessment”); id. at 112 (noting that EPA’s guidelines do not address variability due to factors “such as 

age, ethnic group, socioeconomic status, or other attributes,” and explaining that “there is a need for a nonzero 

default to address the variation in the population expected in the absence of chemical-specific data”); see also id. at 

134 (discussing various factors and recommending that “much more emphasis needs to be placed on describing the 

ranges of susceptibility and risk”); see also id. at 177-82, 196.

45 Id. at 214-15.
25

access to health care, are likely to be more vulnerable to the impact of toxic air pollution.46 

Where a rule affects communities that are disproportionately minority or lower income, EPA 

cannot ignore this greater risk in its assessment. As a key starting point, EPA must assess the 

greater health risk based on socioeconomic status found in epidemiological research studies.47 

As the NAS recognized, “there is growing epidemiologic evidence of interactions between 

environmental stressors and place-based and individual-based psychosocial stressors, driven in 

part by the spatial and demographic concordance between physical and chemical environmental 

exposures and socioeconomic stressors,” and there is also a growing field of information on 

social epidemiology, which addresses the relationship between social factors and disease in 

human populations.48 Data describing these factors are available from the Center for Disease 

Control’s Environmental Public Health Tracking (“EPHT”) Program, the U.S. Agency for Toxic 

Substances and Disease Registry, state and local health agencies, and academic researchers,49

and EPA must consider and use such information in its risk assessment.

Further, EPA must recognize and evaluate the need to consider socioeconomic factors not 

only as part of an environmental justice analysis, but also as part of EPA’s consideration of both 

vulnerability and variability, as core elements of the risk assessment itself. EPA has been 

assessing the demographics of affected communities, pursuant to CAA § 112(f) and the 

Environmental Justice Executive Order 12898.50 This is necessary and important to continue. 

However, in addition to looking at the demographic census data on race, ethnicity, poverty level, 

and similar factors, EPA must also assess the starting point or baseline overall health status of 

the affected individuals and communities using the best available data at a local and national 

level, including the baseline cancer levels, respiratory problems, and health problems associated 

with the toxic chemicals emitted by a source category. Doing so would be consistent with the 

1999 Residual Risk Report.51 Further, EPA has significant research available on which it must 

draw to incorporate “overall health” into its risk assessment. For example, the American Lung 

Association has published research showing that African Americans are at a much higher risk of 

lung cancer than white Americans, and that African-American men have a 37 percent higher risk 

 

46 See, e.g., Chari et al., Integrating Susceptibility, at 1078 & nn.5-10 (citing research); see also Cal. EPA, OEHHA, 

“Cumulative Impacts,”supra, at 6, 10, 12-17.

47 NAS 2009 at 109-10 & tbl. 4-1 (describing the need to consider increased susceptibility due to prior and 

concurrent exposures; and to “social and economic factors”); id. at 220-21 (describing ways to assess cumulative 

risk including by consideration of “epidemiologic concepts” and information, and by considering “what the burden 

of disease is in the context of simultaneous exposure to a number of stressors”); id. at 230 (discussing the role of 

epidemiology and surveillance data).

48 Id. at 230-33.

49 Id. at 232 (describing data available on health status, and patterns of diseases and exposures).

50 Exec. Order 12898, “Federal Actions To Address Environmental Justice,” supra.

51 U.S. EPA, “Residual Risk Report to Congress” at 42, 67 (Mar. 1999), EPA-453/R-99-00 (discussing factor of 

“overall health” and recognizing the need to consider sensitive subpopulations that “consist of a specific set of 

individuals who are particularly susceptible to adverse health effects because of physiological (e.g., age, gender, preexisting conditions), socioeconomic (e.g., nutrition), or demographic variables, or significantly greater levels of 

exposure,” based on various demographic factors).
26

of lung cancer than white men.52 EPA must collect and consider this type of health information 

as part of each risk assessment that disproportionately affects particular minority groups and 

communities, like the one in the rulemaking now in progress. 

Thus far, EPA has failed to adequately assess human variability, particularly the 

increased vulnerability of different socioeconomic groups, or to incorporate the information 

gained from the environmental justice analysis into its risk assessment. In this rulemaking, EPA 

has recognized that there are disproportionate impacts, e.g., on African Americans and low 

income people (living below the poverty level), but EPA did not incorporate the additional 

vulnerability this represents at all into its risk assessment. As the NAS discussed, “EPA should 

compile relevant data related to socioeconomic status (SES), which may serve as a proxy for 

numerous individual risk factors . . . and may be a more direct measure of vulnerability than 

could reasonably be assembled by looking at all relevant individual risk factors.”53 EPA should 

follow the NAS recommendations and science to do so in its residual risk assessment. 

In addition, EPA should simply use a default factor to account for socioeconomic and 

other community-based stressors, just as it does to account for intrinsic biological factors.54 For 

example, it traditionally uses a factor of 100 to account for the use of animal studies, when 

translating such studies to assess human impacts. The Food Quality Protection Act directed EPA 

to use a factor of 10 to account for in utero exposure. California’s Office of Environmental 

Health Hazard Assessment uses a similar factor to account for in utero exposure. EPA also uses 

age-dependent adjustment factors in other contexts. EPA should do the same to account for 

increased vulnerability based on socioeconomic factors or the presence of multiple sources to 

which a community is exposed. 

B. Assess the cumulative burden of exposures to multiple pollutants and sources 

via multiple pathways

1. Perform multipathway assessment for all persistent and all 

bioaccumulative pollutants. 

EPA must assess multipathway (i.e., non-inhalation) risk for all metals and all other 

pollutants with a persistent or bioaccumulative impact, as OEHHA does. Instead, EPA generally 

restricts its multipathway risk screening assessment to only those contaminants identified in the 

2003 Risk Assessment Guidance as being both persistent and bioaccumulative in the 

 

52 Am. Lung Ass’n, “Too Many Cases, Too Many Deaths: Lung Cancer in African Americans” at 1 (2010), 

http://www.lungusa.org/assets/documents/publications/lung-disease-data/ala-lung-cancer-in-african.pdf (explaining 

higher risk to African Americans even though primary factor for lung cancer, i.e., cigarette smoke exposure, is lower 

than for whites); see also State of Lung Disease in Diverse Communities: 2010, available at www.LungUSA.org.

53 NAS 2009 at 226 (citing O’Neill et al. (2003)). 

54 Rachel Morello-Frosch, Zuk, Jerrett, Shamasunder & Kyle, Understanding The Cumulative Impacts of 

Inequalities in Environmental Health: Implications for Policy, 30(5) Health Affairs 879, 883 (2011).
27

environment (i.e., PB-HAPs).55 EPA’s 2003 list of 14 PB-HAPs is incomplete, however, 

because it ignores other HAPs which present a multipathway risk.56 

EPA’s choice to restrict its analysis to only certain contaminants that bioaccumulate is 

not supported by the 2003 Guidance which states that “multipathway risk assessment may be 

appropriate generally when air toxics that persist and which also may bioaccumulate and/or 

biomagnify are present in releases.”57 This guidance does not direct that the multipathway 

assessment be limited to only those contaminants listed as PB-HAPs, but that is how EPA has 

applied it. The choice to exclude those contaminants which persist and accumulate in soils 

underestimates risks from HAPs. The 2003 guidance document recognized deposition of 

persistent HAPs as a source of soil contamination presenting a potentially significant route of 

exposure, particularly for children.

58

Based on EPA’s own guidance, and based on recent scientific information compiled by 

OEHHA, EPA must perform a full multipathway risk assessment for all metals. California 

OEHHA has recommended a multipathway assessment for metals based on scientific research.59 

EPA should consider and apply this science in its risk assessment.

EPA simply may not assume that the ingestion and other multipathway risks are zero for 

persistent pollutants when science shows otherwise. The failure to assess multipathway risk 

from exposure to all PB-HAPs, both individually and cumulatively, results in an underestimate 

of the health risks of HAP emissions.

The following is a list of top priority pollutants for EPA to add to its list of 14 chemicals 

for which multipathway risk should be evaluated, as well as all metals. These chemicals have 

been shown to have a significant potential for deposition and retention within the environment. 

Air emissions of these compounds therefore present a risk to nearby communities via dermal, 

ingestion, and other non-inhalation pathways that are currently not being considered in its 

residual risk assessment. For extensive documentation on the rationale for multipathway 

analysis for these compounds and multipathway exposure parameters please review the OEHHA 

2012 Guidelines for Exposure Assessment.60

i. Arsenic

ii. Hexavalent chromium

 

55 See, e.g., “Draft Residual Risk Assessment for the Ferroalloys Source Category” (Oct. 2011) at 10, EPA-HQOAR-2010-0895-0046 (only analyzing multipathway risk for pollutants on EPA’s outdated PB-HAP list even 

though arsenic is a persistent pollutant and is also emitted).

56 EPA, “PB-HAP Compounds, Risk Assessment and Modeling – Air Toxics Risk Assessment Reference Library, 

Vol. I Tech. Resource Manual, Ch. 4 Air Toxics: Chemicals, Sources, and Emissions Inventories,” at 4-10, Exhibit 

4-2 (2003), http://www.epa.gov/ttn/fera/risk_atra_vol1.html; http://www.epa.gov/ttn/fera1risk_atra_vol 1.html.

57 Id., Part III, Ch. 14“Human Health Risk Assessment: Multipathway,” at 14-1(emphasis added).

58 Id. ch. 20.

59 OEHAA 2012 Guidelines, Appendix E, at E-5, E-10 to E-12, http://oehha.ca.gov/air/hot_spots/SRP/index.html. 

60 Id. App. E.
28

iii. Nickel

iv. Diethylhexylphthalate

v. Beryllium

vi. Selenium

In addition to these six listed by OEHHA, we also urge EPA to assess the persistent effects of 

manganese and naphthalene and add these to the PBT list for similar reasons. Manganese is a 

pollutant to which children have particular exposure and vulnerability, and there is evidence that 

it can pose a multipathway risk due to elevated levels in soils around major emission sources.61 

Naphthalene is a polycyclic aromatic hydrocarbon (PAH) and as such must be considered in the 

POM category which is listed as a PB HAP. Naphthalene has been demonstrated to be persistent 

and to bioaccumulate in biota, particularly shellfish.62

2. Perform multipathway assessment for all pathways of exposure, 

including those that particularly affect children.

EPA should recognize that the science shows additional pathways that it has not 

addressed for certain pollutants, for which it does recognize the need for a multipathway 

assessment. For example, OEHHA has recognized that breast milk exposure can be a pathway 

that creates health risk due to lead.63 EPA should evaluate the research on various pathways of 

toxic exposure discussed by OEHHA.

In addition, science shows that EPA has been relying on outdated estimates of incidental 

soil ingestion exposures and EPA must update these values to ensure that it considers the urban 

child scenario in its multipathway risk assessment.64 Risk assessment of exposure to soil 

contaminants should evaluate both direct exposure, hand-to-mouth, and indirect, object-to-mouth 

exposure. Indirect hand-to-mouth activity is the exposure from young children who touch an 

 

61 See, e.g., ATSDR, “Draft Toxicological Profile for Manganese” at 12 (Sept. 2012) (“Manganese concentrations in 

soil may be elevated when the soil is in close proximity to a mining source or industry using manganese and may 

therefore pose a risk of excess exposure to children who ingest contaminated soil.”) 

http://www.atsdr.cdc.gov/ToxProfiles/tp151.pdf ; see also Cal. EPA, OEHHA, “Development of Health Criteria for 

School Site Risk Assessment Pursuant to Health and Safety Code Section 901(g): Child-Specific Reference Doses 

(chRDs) for School Site Risk Assessment: Manganese and Pentachlorophenol,” at 10 (June 2006) (discussing 

science showing that manganese can accumulate in the brain and showing that ingestion of high levels of manganese 

is associated with harm).

62 R. Yender et al., NOAA, “Managing Seafood Safety after an Oil Spill,” (Nov. 2002).

63 OEHHA 2012 Guidelines, supra note 37, App. E, at E-12, tbl. E3. 

64 As an additional problem, California’s lead in soil standard is more stringent than EPA’s due to more recent 

science on the harm of lead exposure. EPA has recognized that its standard is based on out-dated information about 

lead, that previously assumed children’s blood-lead levels below 10.0 ug/dL was safe. EPA now admits that number 

is not protective, but has not updated its soil standard. See, e.g., “EPA fails to revise key lead-poisoning hazard 

standards,” USA Today (Mar. 10, 2013), http://www.usatoday.com/story/news/nation/2013/03/10/epa-has-notrevised-lead-hazard-standards-for-dust-and-soil/1971209 (“The EPA has not revised key hazard standards that 

protect children from lead poisoning since 2001, despite science showing harms at far lower levels of exposure than 

previously believed.”); Children’s Health Advisory Protection Comm., Letter to Administrator Jackson Regarding 

Childhood Lead Poisoning (Mar. 29, 2012), 

http://yosemite.epa.gov/ochp/ochpweb.nsf/content/chpac_childhood_lead_poison_letter.htm.
29

object or food with soil contaminated hands and then put that object or food into their mouths. 

Published studies show that there is noticeable indirect hand-to-mouth activity in infants and 

children. In fact, one study found that, on average, a toddler will touch an object and then put 

that object into his or her mouth 15 times in one hour. At the high end of the study’s 

distribution (90th percentile), that rate rises to 66 times per hour.65 This same study found a 

statistically significant positive correlation between the frequency of object or food in mouth 

activity and blood lead levels. The 2011 update to EPA’s Exposure Factors Handbook includes 

more recent studies and estimates of hand-to-mouth behavior, which must be used to assess risks 

from exposures to contaminated soils.66

3. Better account for the aggregate impact of inhalation and 

multipathway cancer and chronic non-cancer risk by adding each 

type of similar risk together for all pollutants.

The purpose of the multipathway assessment is to allow EPA to look overall at a person’s 

exposure – not just inhalation, and not just other exposure pathways, in isolation. To do so, EPA 

must add inhalation and multipathway risk. Failing to add up each type of risk in order to come 

up with a total cancer risk number and a total non-cancer number, and then (as further discussed 

below), a cumulative burden metric makes EPA’s overall risk assessment incomplete.

A major problem is that EPA does a screening exercise for multipathway risk and then 

often decides not to do a full multipathway risk assessment. 67 This is problematic for two 

reasons. First, it withholds information from the public on the amount of non-inhalation risk. 

Second, it hampers EPA’s ability to perform a full, cumulative analysis taking into account all 

the relevant exposures. EPA should ensure that for each risk assessment it fully assesses 

multipathway or non-inhalation risk, and that it also combines this with inhalation risk, to come 

up with a cumulative risk level that EPA and the public can then analyze in the rulemaking 

process. 

C. Include Multiple Pollutants. 

1. Assess the combined total of each type of risk for multiple pollutants. 

EPA must assess the total and synergistic cancer risk and total chronic non-cancer risk for 

different pollutants. For example, as OEHHA found, “[t]he potential neurotoxicity of arsenic in 

children, possibly in combination with other environmental agents, is also a concern. Studies in 

 

65

 Ko, S., Schaefer et al., Relationships of Video Assessments of Touching and Mouthing Behaviors During Outdoor 

Play in Urban Residential Yards to Parental Perceptions of Child Behaviors and Blood Lead Levels, 17 J. of 

Exposure Science and Environ. Epidemiology 47 (2007).

66 EPA, Exposure Factors Handbook, 2011 Edition (http://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=236252). 

67 “Draft Residual Risk Assessment for the Ferroalloys Source Category” (Oct. 2011) at 27-31, EPA-HQ-OAR2010-0895-0046 (although the screening analysis showed mercury levels that were 4 times EPA’s screening 

threshold and POM levels that were 60 times EPA’s screening threshold, EPA did not perform a full multipathway 

analysis or add the multipathway risks to the inhalation risks for POM, which EPA also identified as an inhalationbased cancer risk driver).
30

mice (Meija et al., 1997) indicate combined effects of lead and arsenic on the central nervous 

system that were not observed with either metal alone.”68 

In addition, EPA evaluates total cancer risk (using the maximum individual risk or 

“MIR”) and chronic non-cancer risk (using the target-organ specific hazard index “TOSHI”) 

based on the combined exposure to pollutants with a common health impact.69 EPA should 

apply these same principles to create a mechanism for assessing the total acute risk to chemical 

mixtures, such as a TOSHI, that aggregates the acute impacts on the same organ systems for all 

pollutants. 

2. Assess the total cumulative risk burden from all pollutants.

EPA must create a metric to assess the total and cumulative risk burden, rather than only 

looking at each type of risk in a discrete, separate way.70 EPA should be integrating its 

assessments and performing a “comprehensive risk assessment” as the NAS has emphasized.71 

After first assessing the total cancer, chronic non-cancer, and acute risks, for both inhalation and 

multipathway exposure, EPA also must create a metric to assess the total bundle of risks.72 EPA 

must aggregate health risk for each pollutant, and each type of health risk, to create a cumulative 

risk determination for the individual “most exposed” to emissions as the Act requires.73 

Unless and until EPA creates a combined health risk metric, it is unclear how it can make 

an ample margin of safety determination that is based on the full picture of health risk for a 

source category and that can be compared to other source categories. EPA must assess the full 

cumulative burden for public health. By failing to perform a full, cumulative risk assessment, 

EPA fails to gather the information needed to assess whether the risk to public health is 

acceptable under CAA § 112(f)(2).

D. Account for Multiple Sources. 

EPA must assess and account for the cumulative impact and risk caused by exposure to 

multiple source categories’ toxic air emissions. In many communities containing sources of 

toxic air emissions, there are many other nearby sources of toxic air emissions within the 3, 5, 

10, and the full 50 km radius of EPA’s residual risk assessment. Such exposures increase the 

 

68 Cal. EPA, OEHHA, “Prioritization of Toxic Air Contaminants - Children’s Environmental Health Protection Act, 

Arsenic and Arsenic Compounds” at Arsenic-2 (Part II) (Oct. 2001).

69 See, e.g., EPA, OAQPS, “Residual Risk Assessment for the Secondary Lead Smelting Source Category” at 26 

(Dec. 2011), EPA-HQ-OAR-2011-0344-0160.

70 See, e.g., NAS 2009 at 177 (“The underlying scientific and risk-management considerations point to the need for 

unification of cancer and noncancer approaches in which chemicals are put into a common analytic framework 

regardless of type of outcome.”).

71 Id. at 131; see also id. at 132-33 (discussing related issues).

72 Cal. EPA, OEHHA, “Cumulative Impacts,” supra at 19-21, 25 (describing total “pollution burden” as sum of 

exposures, public health effects, and environmental effects); EPA, “Concepts, Methods and Data Sources,” supra, 

at 4-42 to 4-46.

73 42 U.S.C. § 7412(f)(2).
31

vulnerability of a community to new and additional toxic air emissions.

74

 Further, EPA’s own 

environmental justice analysis has found that the sources covered by the rulemaking under 

review here, like other sources of toxic air pollution listed under CAA section 112, such as lead 

smelters, chromium electroplaters, and many others frequently create disproportionate health risk 

for minority and lower income communities. This problem is exacerbated by the fact that 

multiple sources of pollution are more likely to be more concentrated in minority and lower 

income communities, creating a serious environmental justice problem.75 

Therefore, in addition to performing a cumulative assessment from each source category 

alone, EPA also must perform a cumulative analysis that considers source categories’ individual 

impact and risk with that of other sources to which people are exposed.76 EPA has 

acknowledged the importance of addressing multiple source exposures, by stating that it 

“understands the potential importance of considering an individual’s total exposure to HAP in 

addition to considering exposure to HAP emissions from the source category and facility,” and 

that it is “interested in placing source category and facility-wide HAP risks in the context of total 

HAP risks from all sources combined in the vicinity of each source.”77 And, EPA has also 

recognized this need in its recent risk report.78 Yet, so far EPA has failed to follow through on 

this. Although EPA has looked at all sources within a source category, it generally has not 

looked at other exposures. Although EPA has calculated what it calls “facility-wide” risk for 

different sources collocated at the same address, it has not used that number to set standards, and 

it has ignored different sources across the street or in close proximity. 79 Fed. Reg. at 1691.79 

In this rulemaking, EPA recognized that there are sources contributing over 50% to the 

cancer risk above 1-in-1 million and other health risk metrics. But it has provided no discussion 

 

74 See, e.g., NAS 2009 at 214.

75 See, e.g., Cal. EPA, OEHHA, “Cumulative Impacts,” supra. 

76 We support EPA’s recognition of the need to assess whether the maximum exposed individual is exposed to 

emissions from more than one source within each source category, as it does using the AERMOD modeling tool. 

We also appreciate that EPA has considered facility-wide risk in this rulemaking. However, that assessment offers

only part of the picture. And, even on both of these issues, EPA has provided very little information about what it 

included in such assessments. EPA often just states numbers found for facility-wide risk, without explaining where 

those numbers came from, how they were calculated, or what emission sources they cover. 

77 NESHAP: Mineral Wool Production and Wool Fiberglass Manufacturing, 76 Fed. Reg. 72,770, 72,786 (Nov. 25, 

2011). 

78 U.S. EPA, “Concepts, Methods and Data Sources,” supra, at xxxii (defining a cumulative risk assessment as 

including “aggregate exposures by multiple pathways, media and routes over time, plus combined exposures to 

multiple contaminants from multiple sources”).

79 The same problem has occurred in other similar rulemaking. See, e.g., EPA, OAQPS, “Residual Risk Assessment 

for the Secondary Lead Smelting Source Category” (Dec. 2011), EPA-HQ-OAR-2011-0344-0160; “Draft Residual 

Risk Assessment for the Mineral Wool Production and Wool Fiberglass Manufacturing Source Categories” at 23 tbl. 

3.1-1; id. at 30 tbl. 4.1-1 (Sept. 2011), EPA-HQ-OAR-2010-1042-0086; “Residual Risk Assessment for the Chromic 

Acid Anodizing, Decorative Chromium Electroplating, and Hard Chromium Electroplating Source Categories” 

(Aug. 2012), EPA-HQ-OAR-2010-0600-0630; “Draft Residual Risk Assessment for 7 Chemical Source Categories” 

(Nov. 2011), EPA-HQ-OAR-2011-0435-0018; “Draft Residual Risk Assessment for the Ferroalloys Source 

Category” at 27-31 (Oct. 2011) EPA-HQ-OAR-2010-0895-0046; “Residual Risk Assessment for the Oil and Gas 

Production and Natural Gas Transmission and Storage Source Categories,” (Apr. 2012) EPA-HQ-OAR-2010-0505-

4558.
32

of the collocated sources at a given facility or how it reached the percentages listed in the Tables 

in its risk assessment on facility-wide risk, to inform the public. It has provided no reasoned 

justification for using 50% facility-wide risk contribution as a relevant benchmark for action

here. Nor, did it discuss or consider the reductions in facility-wide risk that would occur if it 

were to strengthen regulation of the source categories under review in this rulemaking.

EPA’s failure to assess the combined, cumulative impact on health risk from multiple 

pollution source categories conflicts with the recommendation from the Scientific Advisory 

Board that in May 2010 urged EPA to incorporate cumulative risk into its residual risk analysis. 

The SAB stated that “RTR assessments will be most useful to decision makers and communities 

if results are presented in the broader context of aggregate and cumulative risks, including 

background concentrations and contributions from other sources in the area.”80 

To perform a cumulative risk or impact analysis, EPA should combine current baseline 

emissions, exposures, and health impacts in addition to those of the specific source category EPA 

is reviewing. The NAS explained the need for “[i]ncorporation of background additivity to 

account for . . . [a]dditional sources of exposure to the same chemical or to similarly acting 

chemicals (including endogenous sources). . . .”81 As part of this analysis, EPA should aggregate 

or add the emissions for the most-exposed communities coming from: (1) the source category 

(including all individual sources within it); (2) facility-wide risk from collocated sources outside 

of this category; and (2) all other sources of toxic air pollution in the area. Virtually all of the 

existing federal air toxics standards (under section 112(d)) require periodic testing and 

monitoring, and this is something EPA must ensure is included in all rules as it updates them. 

Using these data, EPA can aggregate the community’s exposure and assess the full health threats 

faced by the affected community, including from the source under review. 

EPA must also consider the research that has already occurred to assess health risk from 

toxic air pollution in urban communities nationwide.82 EPA should also draw on the OEHHA 

cumulative assessment approach.83 EPA should consult with OEHHA and investigate the 

scientific approach it is using to address cumulative impacts, and consider and apply a similar 

science-based approach in its residual risk assessment. 

Further, the NAS has recommended that EPA evaluate “background exposures and 

vulnerability factors,” as well as use “epidemiologic and toxicologic evidence” in its risk 

 

80 SAB May 2010 at ii, supra note 41, at 10. 

81 NAS 2009 at 180 (explaining that this may require the use of default factors).

82 See, e.g., Rachel Morello-Frosch & Bill M. Jesdale, Envtl. Health Perspectives, Separate and Unequal: 

Residential Segregation and Estimated Cancer Risks Associated with Ambient Air Toxics in U.S. Metropolitan 

Areas, 114(3) Envtl. Health Perspectives 386 (2006) (assessing toxic air pollution cancer risk for 309 metropolitan 

areas encompassing 45,710 tracts); “National Air Toxics Program: The Integrated Urban Strategy,” 64 Fed. Reg. 

38,706, 38,738 (July 19, 1999). 

83 See, e.g., Cal. EPA, “Cumulative Impacts,” supra.
33

assessment.

84

 Rather than separating an environmental justice analysis and considerations of 

inequality from the risk assessment, considering these factors as part of the cumulative risk 

assessment – because of the increased vulnerability created – would be a more effective, 

meaningful, and scientific approach. 

EPA stated in this rulemaking that “we are interested in placing source category and 

facility-wide HAP risks in the context of total HAP risks from all sources combined in the 

vicinity of each source,” but that “we are concerned about the uncertainties of doing so.” 79 Fed. 

Reg. at 1696. EPA has failed to explain why this would “make the assessments too unreliable,” 

rather than providing additional information on additional health risks that it is currently 

ignoring, so that EPA could then take a scientifically defensible approach to protect public 

health, with a more complete view of the most-exposed person’s risks. 

In assessing a source category’s emission contributions in affected communities and 

considering whether these contributions cause the most-exposed people to experience an 

unacceptable level of public health risk when combined with the existing baseline from past 

emissions, other HAP emissions, and the community’s health status, EPA can describe and 

manage uncertainties, as it does in other aspects of the risk assessment, 79 Fed. Reg. at 1691-95,

and other federal agencies do for many other analyses.85 Uncertainties do not justify refusing to 

assess and address the severe cumulative harm and risk to local communities from the source 

categories under review here (or other air toxics sources). Much of risk assessment is about 

managing uncertainties, and that is not reason for EPA to avoid appropriately regulating sources 

under § 112(f)(2). Rather, there is no excuse for treating an unknown amount of additional risk 

as a missing default, to use the NAS term.

As a scientific and policy matter, where there is exposure to air toxic emissions beyond 

the individual source category, the level of total risk that is occurring, including the baseline 

health risk and the risk from other sources, is greater. Thus, the total risk that is unacceptable for 

the most-exposed person must in fact be lower for each source category that person is exposed 

to, because it combines with other risks to create a total risk from all regulated source categories 

 

84 NAS 2009 at 221-23 (discussing Menzie et al. 2007 model); id. at 230 (discussing the role of epidemiology and 

surveillance data).

85 See, e.g., 42 U.S.C. §§ 7475(a)(3), 7503(a)(1) (requiring a localized, cumulative assessment of whether or not a 

new or modified source’s additional emissions will cause an attainment area to deteriorate, or will make it difficult 

for a nonattainment area to make progress toward achieving the national ambient air quality standards); New York v. 

EPA, 443 F.3d 880, 883 n.1 (D.C. Cir. 2006) (citing New York v. EPA, 413 F.3d 3, 11-14 (D.C. Cir. 2005)); see also 

40 C.F.R. § 1508.27(b)(7) (requiring a consideration of “[w]hether the action is related to other actions with 

individually insignificant but cumulatively significant impacts. Significance exists if it is reasonable to anticipate a 

cumulatively significant impact on the environment. Significance cannot be avoided by terming an action 

temporary or by breaking it down into small component parts”); see also 40 C.F.R. § 1508.7;Nat’l Wildlife Fed’n v. 

Nat’l Marine Fisheries Serv., 524 F.3d 917, 930 (9th Cir. 2008) (applying 16 U.S.C. § 1536(a)(2) to enforce the 

Endangered Species Act duty to ensure against jeopardy which includes the requirement to assess a newly proposed 

action in the context of all other impacts, and determine whether or not the specific action will “tip a species from a 

state of precarious survival into a state of likely extinction,” or, where baseline conditions already jeopardize a 

species, whether it will “deepen[] the jeopardy by causing additional harm”).
34

which must be minimized. Looking at a source category’s contribution of risk in isolation is 

equivalent to ignoring the facts and pretending other health risks are not occurring. EPA may 

not decide that it is okay for a person to be exposed at a higher level simply because they live in 

a community where they are exposed to multiple sources of air pollution. That is the opposite of 

what EPA is required to do – protect the people in local communities who are most exposed and 

most vulnerable to air pollution. It also conflicts with EPA’s own commitment to consider and 

provide environmental justice to overburdened communities.

At minimum, until EPA develops a data-driven approach to comprehensively model 

cumulative risk or impacts from multiple sources, EPA must not treat multiple source exposure 

as a missing default, or ignored amount of health risk. EPA must incorporate an explicit default 

or uncertainty factor to adjust the degree to which each individual source category is contributing 

to the total risk experienced by the most-exposed individuals. For example, wherever there is 

evidence that the source category is contributing pollutants on top of a history of other exposures 

or is contributing pollutants in addition to other source categories, the “unacceptable” level of 

cancer, non-cancer chronic, and acute risk from the source category must be adjusted downward 

based on the number of other facilities contributing HAP exposure risks (such that no single 

source category could consume all of it, when the most-exposed person is exposed to many other 

source categories). For a source category in an area with up to 10 other HAP-emitting facilities, 

this default or uncertainty factor should equal at least 10, consistent with the common scientific 

use of this factor for other kinds of vulnerability.86 

E. Account for Additional Risk and Uncertainty. 

In addition to and related to many of the issues already discussed, EPA must stop treating 

various types of risk as zero when the science shows risk is present; simply because EPA has not 

yet developed a risk function for a pollutant, type of exposure, or type of risk, does not mean risk 

does not exist and can be ignored.87 As the NAS explained, EPA should use “explicitly stated 

defaults to take the place of implicit or missing defaults,” and “[k]ey priorities should be 

development of default approaches to support risk estimation for chemicals lacking chemicalspecific information to characterize individual susceptibility to cancer . . . and to develop a doseresponse relationship.”88

1. EPA must not treat risk as zero for a pollutant for which it has no 

reference value.

As the NAS explained, it is a problem that “agents that have not been examined 

sufficiently in epidemiologic or toxicologic studies are insufficiently included in or even 

 

86 For areas with more facilities, which cause an even greater level of health risk combined, the UF should be 

adjusted accordingly, i.e., 11-20 facilities would result in an UF of 20, and more than 20 would result in an UF of 

100, so the source category’s contribution is no higher than 1/100 of the threshold.

87 See, e.g., NAS 2009 at 203-04, 207.

88 Id. at 207. 
35

excluded from risk assessments” by EPA.89 Many chemicals have no cancer slope factor, RfD, 

RfC.90 It is not appropriate to treat such compounds “as though they pose no risk that should be 

subject to regulation.”91 The NAS has recommended that EPA develop “explicit defaults to use 

in place of missing defaults,” including for its “untested-chemical assumption,” i.e., that a 

chemical with no reference value poses no risk.92

Where there is no reference value for a pollutant, EPA may not simply ignore health risks 

associated with these pollutants completely in its analysis by hiding behind uncertainty. Section 

112 requires EPA to address and regulate all emitted HAPs. EPA states that the lack of reference 

values “could result in quantitative estimates understating HAP risk.”

93

 In fact, an 

understatement of risk for pollutants that are excluded from the analysis is certain because EPA 

has performed no quantitative assessment of health risk for those pollutants at all. The absence 

of a reference value means that EPA does not know by how much it is underestimating risk to 

human health, but it does know that its assessment is an underestimation. 

Although EPA makes these general statements in the preamble, it does not advise the 

public as to which pollutants in this rulemaking are chemicals for which EPA has failed to assess 

risk at all quantitatively due to the lack of reference values, or pollutants for which EPA has only 

performed what it calls a qualitative assessment.94 To inform the public and fulfill its notice and 

comment duty under the Clean Air Act, EPA must provide information on which chemicals these 

are, and seek additional information regarding these specific pollutants, before deciding not to 

assess health risk from them at all quantitatively. 

In the absence of an available reference dose, EPA must, at minimum, add an uncertainty 

factor to account for the additional risk that a HAP likely causes, until such time as EPA does 

have a reference value to use. Using a protective uncertainty factor – developed based on the 

best available science – would allow EPA to satisfy its legal duty under section 112(f)(2) to 

prevent unacceptable health risk, and ensure an “ample margin of safety to protect public 

health.”95 The NAS has described an approach EPA can use to account for this risk, and 

explained that this approach “is based on the notion that for virtually all chemicals it is possible 

to say something about the uncertainty distribution regarding dose-response relationships.”96 For 

 

89 Id. at 193.

90 Id. at 203.

91 Id. at 193.

92 Id. at 203.

93 79 Fed. Reg. at 1693.

94 Id. (“Further, HAP not included in the quantitative assessment are assessed qualitatively and considered in the risk 

characterization that informs the risk management decisions, including with regard to consideration of HAP 

reductions achieved by various control options.”)

95 42 U.S.C. § 7412(f)(2).

96 NAS 2009 at 203 (emphasis added).
36

example, EPA can use information on chemical structure, available toxicologic tests and model 

or experimental data, and data on similar chemicals that have been studied.97

Section 112(f)(2) of the CAA creates a critical duty and opportunity for EPA to conduct a 

comprehensive and protective analysis of risk to public health and the environment. In view of 

this, it is a serious problem for EPA’s analysis that some pollutants continue to have no reference 

values.98 Over twenty years after the Clean Air Act was amended, sufficient studies for some 

pollutants have not been conducted to calculate reference doses, reference concentrations, or 

potency values. Moreover, the Integrated Risk Information System (“IRIS”) review process has 

been bogged down for many pollutants as the Government Accountability Office recently 

documented.99 As the Center for Progressive Reform (“CPR”) has recognized, EPA should 

prevent the delay in this process from undermining its residual risk analysis for source categories 

under review.100 

For pollutants currently under IRIS assessment, EPA must use the best available 

scientific information from the IRIS review during current rulemakings.

101

 At minimum, EPA 

must account for the lack of reference values or the lack of an up-to-date final IRIS assessment 

rather than just allowing important rulemakings to go by without any consideration of health risk 

due to such pollutants.102

 

97 Id. at 204.

98 See, e.g., 79 Fed. Reg. at 1693. 

99 U.S. Gov’t Accountability Office, GAO-12-42, Chemical Assessments: Challenges Remain with EPA’s 

Integrated Risk Information System Program 17-18 (2011).

100 See Rena Steinzor et al., Setting Priorities for IRIS: 47 Chemicals that Should Move to the Head of the RiskAssessment Line, Ctr. For Progressive Reform (Dec. 2010), 

(http://www.progressivereform.org/articles/IRIS_Priorities_1010.pdf. CPR’s analysis of IRIS offers a critical 

expose of these problems. EPA’s IRIS: A Database With Blind Spots, Ctr. For Progressive Reform, 

http://www.progressivereform.org/iris.cfm (last visited June 27, 2013). See also Gov’t Accountability Office, GAO11-278, “High Risk Series: An Update” (2011); Gov’t Accountability Office, GAO-09-774T, 

http://www.gao.gov/new.items/d11278.pdf; Gov’t Accountability Office, “EPA Chemical Assessments: Process 

Reforms Offer the Potential to Address Key Problems,” (2009); Gov’t Accountability Office, GAO-08-743T, 

http://www.gao.gov/new.items/d09774t.pdf; Gov’t Accountability Office, “Toxic Chemicals: EPA’s New 

Assessment Process Will Increase Challenges EPA Faces in Evaluating and Regulating Chemicals” (2008); Gov’t 

Accountability Office, GAO-08-440, 29, (2008), http://www.gao.gov/new.items/d08743t.pdf; Gov’t Accountability 

Office, “Chemical Assessments: Low Productivity and New Interagency Review Process Limit the Usefulness and 

Credibility of EPA’s Integrated Risk Information System” (2008), http://www.gao.gov/new.items/d08440.pdf.

101 Integrated Risk Information System (IRIS); Announcement of 2012 Program, 77 Fed. Reg. 26,751 (May 7, 

2012). 

102 See, e.g., Draft Residual Risk Assessment for the Mineral Wool Production and Wool Fiberglass Manufacturing 

Source Categories at 23 tbl. 3.1-1; id. at 30 tbl. 4.1-1 (Sept. 2011), EPA-HQ-OAR-2010-1042-0086 (due to lack of 

reference value for hydrogen fluoride (HF), antimony, and other pollutants, EPA failed to account for any health risk 

from these pollutants). Similarly, there is no reference value for lead, and no safe level of lead exposure. Although 

information exists regarding how EPA could try to address this (such as using California’s benchmark for action of 

avoiding a blood-lead level increase of 1.0 ug/dL), EPA regularly assesses only whether a source, alone, will cause 

an exceedance of the 2008 Lead National Ambient Air Quality Standards, instead of evaluating how to prevent harm 

from the lead emissions of a source category, in combination with other pollutants and other sources. See, e.g., id. at 

11; “Secondary Lead Smelting Residual Risk Assessment” at 12 (Dec. 2011), EPA-HQ-OAR-2011-0344-0160. 
37

2. EPA must account for the cumulative risk of upsets and malfunctions, 

instead of ignoring this risk.

As another example of the problem of ignoring health risk in its assessment, EPA ignores 

the higher emissions caused by malfunction or upset emissions, which can accumulate and 

combine to increase public health impacts and risk. Its acute risk assessment uses a factor of 10 

(or only 2 for equipment leaks), which fails to adequately account for additional health risk from 

malfunctions. “Upsets are a significant problem for many areas, including rural ones, but they 

are a particular problem for the predominantly lower income communities of color surrounding 

many refinery and chemical complexes.”103 Malfunction or upset events increase emissions and 

thereby pose increased health risks which EPA must consider. Where control equipment fails, 

emissions could be at least 100 times greater (e.g., in the circumstance where a control device 

has 99% efficiency, such that an uncontrolled release would cause 100 times the usual amount of 

emissions).

Failing to look at the true potential for spikes in emissions over a person’s lifetime may 

underestimate acute risk, cancer risk and the amount of chronic risk based on pollutants that 

persist in the environment, such as PCBs, POM, lead, and cadmium. Ignoring these emission 

spikes is equivalent to treating additional health risk caused by exceedances as zero. EPA knows 

that there is additional risk from malfunctions and violations, and that this additional risk should 

not be ignored in its risk assessment. 

To assess the health risk from malfunctions, EPA has information available or can collect 

information on major sources’ malfunction and violation histories.104 Moreover, EPA regularly 

uses statistical methods and probability factors, which are readily available tools that EPA can 

also use to assess health risk due to malfunctions, to set clean air standards. Further, to calculate 

acute health risk, EPA uses what it calls a “worst case” scenario approach that attempts to 

account for some variability under the existing standard, which (although this does not fully do 

so) shows that the agency could similarly add a factor to account for malfunctions for acute and 

other types of health risk.

 

103 Envtl. Integrity Project, Gaming the System: How Off-the-Books Industrial Upset Emissions Cheat the Public 

Out of Clean Air at 1-2 (Aug. 2004) (finding significant likelihood of an upset at refineries, chemical plants, gas 

plants and a carbon black plant, and finding that the resulting emissions release is many times higher than the 

amount of otherwise-reported annual emissions),

http://www.environmentalintegrity.org/news_reports/Report_Gaming_System.php.

104 See, e.g., EPA, Enforcement and Compliance History Online (ECHO), www.epa.gov/echo; Kelly Haragan, Envtl. 

Integrity Project, “Gaming the System: How Off-the-Books Industrial Upset Emissions Cheat the Public Out of 

Clean Air” (Aug. 2004), 1-2, 5, http://www.environmentalintegrity.org/news_reports/Report_Gaming_System.php 

(finding significant likelihood of an upset at refineries, chemical plants, gas plants and a carbon black plant, and 

finding that the resulting emissions release is many times higher than the amount of otherwise-reported annual 

emissions and that “releases from upsets actually dwarf a facility’s routine emissions.”).
38

In addition, EPA must not underestimate acute health risk from equipment leaks as it has 

proposed to do in this rulemaking. EPA found significant numbers for acute health risk from 

these source categories, often above 1. Yet, EPA also stated that it was only using a default 

factor of 2 to account for such health risk from equipment leaks, rather than the factor of 10 it 

used for all other such risk. 79 Fed. Reg. at 1688. When leaks can continue indefinitely and 

there is no limit on the amount of HAPs may come from such leaks, EPA has given no valid 

basis for using such a low factor to account for the risk from these sources. 

F. Account for Cumulative Impacts of Multiple Exposures and Vulnerabilities 

by Shifting the Level of Risk Which Triggers Policy Action. 

EPA has a longstanding policy of assuming that it is possible to find a safe or acceptable 

level of cancer and other kinds of health risks. Currently available science debunks this 

assumption because there is so much uncertainty built into EPA’s risk assessment, and because 

EPA lacks information on so many pollutants. For communities overburdened by pollution, this 

policy is especially problematic. 

As a major example, EPA should recognize that cancer risk from a major industrial 

source category of toxic air pollution (listed under CAA § 112) that is 100-in-1 million or less 

cannot be presumed safe or “acceptable.” Since 1990, however, EPA has made this assumption. 

EPA based this assumption not on scientific information about cancer risk, but on an unusual 

study of people’s perceptions of their own risk from 1988, known as the Survey of Societal Risk 

(July 1988), to consider various types of health risks at that time.105 Using a comparison of 

cancer risk to other kinds of hazards Americans then faced in their daily lives, EPA effectively 

chose a number out of a hat that it would consider acceptable. EPA looked at an odd collection 

of risks, such as dangers from driving a car, and found that “the presumptive level established for 

MIR [maximum individual risk of cancer] of approximately 1 in 10 thousand is within the range 

for individual risk in the survey, and provides health protection at a level lower than many other 

risks common ‘in the world in which we live.’”106

EPA has failed to revisit or update this number for the decades since, even though 

scientists have made breakthroughs on early-life exposure and children’s vulnerability; 

biomonitoring and other data on adult body burdens of chemicals; the vulnerability of 

overburdened communities, including socioeconomic disparities; and on ways to analyze and 

control the impacts of pollutants on human health. 

LANDMARKS SINCE 1990

 

105 Benzene Rule Docket No. OAQPS 79-3, Part I, Docket Item X-B-1, EPA Air Docket (cited at Nat’l Emission 

Standards for Hazardous Air Pollutants; Benzene Emissions from Maleic Anhydride Plants, Ethylbenzene/Styrene 

Plants, Benzene Storage Vessels, Benzene Equipment Leaks, and Coke By-Product Recovery Plants, 53 Fed. Reg. 

28,496, at 28,512-13 (July 28, 1988)).

106 54 Fed. Reg. 38,044, 38,046 (Sept. 14, 1989) (emphasis added) (quotation omitted).
39

1990 Clean Air Act Amendments required technology-based control for hazardous air 

pollutants and 8-year review of residual health risk to ensure protection of 

communities.

1993 National Research Council published Pesticides in the Diets of Infants and 

Children, finding that children are not little adults, and have greater exposures and 

susceptibility.

1994 President Clinton signed Executive Order 12898 on Environmental Justice.

1996 Food Quality Protection Act passed unanimously with a 10-Fold Children’s 

Safety Factor.

Safe Drinking Water Act amendments required attention to susceptibility of 

children.

EPA announced a new National Agenda to Protect Children’s Health.

1997 President Clinton signed the Children’s Environmental Health Executive Order 

13045.

2000 EPA first published America’s Children and the Environment. 

2009 National Academy of Science published Science and Decisions: Advancing Risk 

Assessment.

2009 Then-EPA Administrator Jackson declared environmental justice and children’s 

health priorities.

2011 EPA announced Plan EJ 2014 including rulemaking and science goals.

It is time for EPA scientists and science policymakers to revisit the outdated assumption 

EPA makes regarding what level of cancer risk triggers policy interventions. EPA’s own policy 

regarding carcinogens recognizes that they have no safe threshold of exposure. EPA has 

appropriately recognized that cancer risks add up to increase lifetime risk. EPA cannot reconcile 

what it knows – and does not know – about carcinogens with its outdated presumption that a 

cancer risk of 100-in-1 million is acceptable. 

Importantly, EPA’s presumption regarding cancer risk ignores the experience of 

communities exposed to multiple sources and types of sources of pollution. Even if some level 

of risk might otherwise be acceptable, that cannot be assumed to be true for communities 

exposed to more than one source that is causing that level of health risk. EPA has a 

responsibility to address the science on cumulative impacts and risk and update its assumptions 

accordingly, to acknowledge that cancer risks below 100-in-1 million cannot be presumed safe.
40

EPA should also reform how it evaluates chronic and acute hazard indices, in which a 

risk number below 1 does not result in policy changes or standards. EPA should instead factor in 

uncertainties and vulnerability factors that adjust the “acceptable level of risk.” This is currently 

done under FQPA when EPA uses factors to determine a Target Margin of Exposure and risks 

below this level warrant increased scrutiny and changes to allowable exposures.107

In the face of increasing evidence which challenges the assumption of a safe or 

acceptable level of exposure, EPA should also update its risk assessment approach to reduce 

risks to the lowest possible level, to protect public health, rather than suggesting that there is a 

safe or acceptable level. EPA must recognize that it does not know what, if any, would be a 

“safe” level. It has no valid basis for stating to the public that exposure to lifetime cancer health 

risks below 100-in-1 million can be presumed safe, and it has failed to provide any evidence for 

this conclusion in connection with the current source categories under review. 

* * *

Thank you for your consideration of these comments which EPA should adopt to follow 

the Clean Air Act and protect public health from the source categories under review in this 

rulemaking. An accompanying CD-ROM, sent by U.S. Mail, contains documents cited in these 

comments for EPA’s review.

For further information regarding these comments, please contact Emma Cheuse or Jim 

Pew at Earthjustice (jpew@earthjustice.org, echeuse@earthjustice.org) or (202) 667-4500.

 

107 See, e.g., EPA, “Sulfuryl Fluoride; Proposed Order Granting Objections to Tolerances and Denying Request for a 

Stay, Proposed Rule,” 76 Fed. Reg. 3422, 3427 (Jan. 19, 2011) (explaining use of MOE).
41

APPENDIX A: ADDITIONAL SOURCES

In general, for further information on each of the topics discussed here, the agency 

should consult the following sources:

1. George Alexeef et al., A Screening Method for Assessing Cumulative Impacts, 9 Int’l 

Journal of Envtl. Research and Pub. Health 648-659 (2012); doi:10.3390/ijerph9020648.

2. Ramya Chari et al., Integrating Susceptibility into Environmental Policy: An Analysis of 

the National Ambient Air Quality Standard for Lead, 9 Int’l Journal of Envtl. Research 

Pub. Health1077-1096 (2012).

3. Peter L. deFur et al., Vulnerability as a Function of Individual and Group Resources in 

Cumulative Risk Assessment, 115(5) Envtl. Health Perspectives 817-24 (2007).

4. Kelly Haragan, “Gaming the System: How Off-the-Books Industrial Upset Emissions 

Cheat the Public Out of Clean Air,” Envtl. Integrity Project (Aug. 2004),

http://www.environmentalintegrity.org/news_reports/Report_Gaming_System.php.

5. Sarah Janssen et al., Strengthening Toxic Chemical Risk Assessments to Protect Human 

Health, NRDC, Sci. & Envtl. Health Network, Issue Paper, (Feb. 2012). 

6. Kristen Lombardi, “‘Upset’ emissions: Flares in the air, worry on the ground,” The Ctr. 

for Pub. Integrity, (May 31, 2013, 11:57 AM), 

http://www.publicintegrity.org/2013/05/21/12654/upset-emissions-flares-air-worryground.

7. Paul Mohai, Byoung-Suk Kweon, Sangyun Lee & Kerry Ard, Air Pollution Around 

Schools Is Linked to Poorer Student Health And Academic Performance, 30(5) Health 

Affairs 852 (published online May 4, 2011; 10.1377/hlthaff.2011.0077).

8. Rachel Morello-Frosch et al.,, Understanding the Cumulative Impacts of Inequalities In 

Environmental Health: Implications for Policy, 30(5) Health Affairs (2011).

9. Rachel Morello-Frosch & Bill M. Jesdale, Separate and Unequal: Residential Segregation 

and Estimated Cancer Risks Associated with Ambient Air Toxics in U.S. Metropolitan 

Areas, 114(3) Envtl. Health Perspectives 386 (2006). 

10. Nat’l Research Council, Nat’l Acad. of Sciences, Science and Decisions: Advancing Risk 

Assessment (2009).http://www.nap.edu/catalog.php?record_id=12209.

11. Nat’l Acad. of Sciences, Phthalates and Cumulative Risk Assessment: The Tasks Ahead

(2008).

12. Office of Envt’l Health Hazard Assessment, “Air Toxics Hot Spots Risk Assessment 

Guidelines: Technical Support Document for Exposure Assessment and Stochastic 
42

Analysis, Scientific Review Panel Draft,” Cal. EPA (June 20, 2012), 

http://oehha.ca.gov/air/hot_spots/SRP/index.html.

13. Office of Envt’l Health Hazard Assessment, California Communities Environmental 

Health Screening Tool (CalEnviroScreen 1.0), Cal. EPA (April 2013), 

http://oehha.ca.gov/ej/ces042313.html. 

14. Office of Envt’l Health Hazard Assessment, Technical Support Document for Cancer 

Potency Factors: Methodologies for Derivation, Listing of Available Values, and 

Adjustments to Allow for Early Life Stage Exposures, Cal. EPA (May 2009), 

http://oehha.ca.gov/air/hot_spots/tsd052909.html.

15. Office of Envt’l Health Hazard Assessment, Appendix J: “In Utero and Early Life 

Susceptibility to Carcinogens: The Derivation of Age-at-Exposure Sensitivity Measures,”

Cal. EPA (May 2009), 

http://oehha.ca.gov/air/hot_spots/tsd052909.html,http://oehha.ca.gov/air/hot_spots/2009/

AppendixJEarly.pdf.

16. Office of Envt’l Health Hazard Assessment, “Cumulative Impacts: Building a Scientific 

Foundation,” Cal. EPA (Dec. 31, 2010), http://oehha.ca.gov/ej/pdf/CIReport123110.pdf.

17. Office of Envt’l Health Hazard Assessment, Child-specific Health Reference Doses, Cal. 

EPA (June 22, 2009), http://oehha.ca.gov/public_info/public/kids/chrdtable.html

18. Dawn Reeves, Sierra Club Calls For EPA To Address Cumulative Impacts Under NEPA, 

Inside EPA, Vol. 33, No. 5 (Aug. 31, 2012).

19. James L. Sadd et al., Playing It Safe: Assessing Cumulative Impact and Social 

Vulnerability through an Environmental Justice Screening Method in the South Coast Air 

Basin, California, 8 Int’l Journal of Envtl. Research and Pub. Health 1441-1459 (2011). 

20. Elizabeth Shogren & Robert Bennincasa, “Baton Rouge’s Corroded, Overpolluting 

Neighbor: Exxon Mobil,” Nat’l Pub. Radio, (May 30, 2013, 4:29 PM), 

http://www.npr.org/2013/05/30/187044721/baton-rouge-s-corroded-overpollutingneighbor-exxon.

21. Letter from Pamela Shubat, Chair, Children’s Health Protection Advisory Committee, to 

Lisa Jackson, Administrator, EPA (Oct. 21, 2010), 

http://yosemite.epa.gov/ochp/ochpweb.nsf/content/CHPAC_NRC_Report.htm.

22. Sierra Club, “The State of Detroit’s Environment: An Initial Assessment Using the 

Framework of Environmental Justice (2013).

23. Jason Su et al., An Index for Assessing Demographic Inequalities in Cumulative 

Environmental Hazards with Application to Los Angeles, California, 43(20) Envtl. Sci. 

Tech. 7626–7634 (2009)).
43

24. U.S. EPA, “Report of the Task Group of the Children’s Health Protection Advisory 

Comm. on America’s Children & the Env’t,” 3d Ed. (2010). (2010), 

25. U.S. EPA, Sci. Advisory Bd., Review of EPA’s draft entitled, “Risk and Technology 

Review (RTR) Risk Assessment Methodologies: For Review by the EPA’s Science 

Advisory Board with Case Studies – MACT I Petroleum Refining Sources and Portland 

Cement Manufacturing,” EPA-SAB-10-007 (May 2010).
44

APPENDIX B: SCIENTIFIC AND POLICY DEVELOPMENTS

Summary of Major Developments Relevant to 

Children’s Health Risk and Environmental Justice

In recent decades, many major scientific and policy developments have occurred, all directing 

that the federal government – and, in particular, EPA – must fully account for health risk to 

children due to early-in-life exposure, and for the need to consider and provide environmental 

justice. Science now shows that “[e]nvironmental contaminants can affect children quite 

differently than adults, both because children may be more highly exposed to contaminants and 

because they may be more vulnerable to the toxic effects of contaminants.”108 

 In 1993, the National Research Council published Pesticides in the Diets of Infants and 

Children, finding that children are not little adults, and have greater exposures and 

susceptibility.109

 In 1994, President Clinton signed Executive Order 12898 on Environmental Justice.110

 In 1996, Congress enacted the Food Quality Protection Act and the Safe Drinking Water 

Act amendments, which explicitly require consideration of the susceptibility of children 

and due to early exposure.111 This same year, EPA announced a new National Agenda to 

Protect Children’s Health.

 

108 U.S. EPA, “America’s Children & the Env’t,” 3d Ed. at 8 (2013).

109 Nat’l Research Council, “Pesticides in the Diets of Infants and Children” (1993); see also Hugh A. Barton et al., 

Assessing Susceptibility from Early-Life Exposure to Carcinogens, 113(9) Envtl. Health Perspectives 1125 (2005); 

Dale Hattis et al., Age-Related Differences in Susceptibility to Carcinogenesis: a Quantitative Analysis of Empirical 

Animal Bioassay Data, 112(11) Envtl. Health Perspectives 1152 (2004).

110 Exec. Order No. 12898, 3 C.F.R. 859 (1995), reprinted as amended in 42 U.S.C. § 4321 (1998). 

111 21 U.S.C. § 346a(b)(2)(C) (requiring that, in taking certain actions on pesticides “an additional tenfold margin of 

safety for the pesticide chemical residue and other sources of exposure shall be applied for infants and children to 

take into account potential pre- and post-natal toxicity and completeness of the data with respect to exposure and 

toxicity to infants and children”) (emphasis added); 42 U.S.C. § 300g-1(b)(1)(C) (requiring that, in selecting 

unregulated contaminants for consideration, EPA “shall take into consideration, among other factors of public health 

concern, the effect of such contaminants upon subgroups that comprise a meaningful portion of the general 

population (such as infants, children, pregnant women, the elderly, individuals with a history of serious illness, or 

other subpopulations) that are identifiable as being at greater risk of adverse health effects due to exposure to 

contaminants in drinking water than the general population”) (emphasis added); id. § 300j-18(a)(1) (requiring EPA 

to “identify groups within the general population that may be at greater risk than the general population of adverse 

health effects from exposure to contaminants in drinking water. The study shall examine whether and to what degree 

infants, children, pregnant women, the elderly, individuals with a history of serious illness, or other subpopulations 

that can be identified and characterized are likely to experience elevated health risks, including risks of cancer, from 

contaminants in drinking water. . . .”) (emphasis added). 
45

 In 1997 the President issued the Children’s Environmental Health Executive Order (No. 

13045) on the need to address risks to children.112

 In 2000, EPA first published America’s Children and the Environment, which it has since 

updated.113

 In 2006, EPA issued new guidance on protecting children from environmental health 

risks as part of the rulemaking process.114 Among other things, this Guide, at 8, 

recognized the problem of disproportionate risk to children because they may be more 

sensitive to pollution and exposed at a higher rate than adults because of their 

developmental stage. This Guide also recognized the need “to think in terms of the broad 

range of early life, pre-natal and post-natal, environmental exposures that may affect the 

incidence of disease or alter development.”115

 In 2008, EPA updated the Child-Specific Exposure Factors Handbook.116 

 In 2008 and 2009, the major National Academy of Sciences reports – Science and 

Decisions: Advancing Risk Assessment (“NAS 2009”), and Phthalates and Cumulative 

Risk Assessment: The Tasks Ahead (2008) – were released, re-emphasizing the 

importance of addressing real-world risk to children and cumulative health risk. 

 In 2009, EPA Administrator Jackson declared environmental justice and children’s health 

priorities. 

 In 2010, EPA Administrator Jackson issued EPA’s Action Development Process: Interim 

Guidance on Considering Environmental Justice During the Development of an 

Action.

117

 In 2011, EPA Administrator Jackson announced Plan EJ 2014 including rulemaking and 

science goals to finally achieve the goals of the 1994 Environmental Justice Executive 

Order.118 EPA continues to work to issue guidance that will advance these goals. 

In addition, in recent years, EPA’s Children’s Health Protection Advisory Committee has 

recommended addressing the developmental origins of adult disease that come from childhood 

 

112 Exec. Order 13045, 62 Fed. Reg. 19,885 (Apr. 21, 1997). 

113 U.S. EPA, “American’s Children and the Env’t” (3d ed. 2013), 

http://www.epa.gov/opeedweb/children/publications/index.html. 

114 U.S. EPA, “Guide to Considering Children’s Health When Developing EPA Actions: Implementing Executive 

Order 13045 and EPA’s Policy on Evaluating Health Risks to Children” (2006), 

http://yosemite.epa.gov/ochp/ochpweb.nsf/content/ADPguide.htm/$File/EPA_ADP_Guide_508.pdf. 

115 Id.

116 U.S. EPA, Child-Specific Exposure Factors Handbook (2008).

117 U.S. EPA, “EPA’s Action Development Process: Interim Guidance on Considering Environmental Justice 

During the Development of an Action” (2010). http://www.epa.gov/compliance/ej/resources/policy/ejrulemaking.html. 

118

 Plan EJ 2014, U.S. EPA, http://www.epa.gov/compliance/ej/plan-ej/index.html. 
46

exposure to air pollution and other environmental contaminants.119 Similarly, the Committee has 

recommended that EPA incorporate a more robust analysis of childhood and pre-natal exposure 

to environmental contaminants into its risk assessment method.120 

The Science Advisory Board (SAB) has also urged EPA to address the greater risk to 

children from hazardous air pollution.121 As the SAB further explained: “California’s Office of 

Environmental Health Hazard Assessment (OEHHA) has very recently updated its methodology 

in ways that could affect the development of RfC and URE (unit risk estimate) values. EPA 

should examine these developments to make sure that the RTR process adequately covers 

children’s risks.”122

Finally, during the last decade, OEHHA has also released a number of groundbreaking 

scientific determinations and protocols to consider and address children’s health, early life 

exposure, and cumulative impacts, which are cited in this document, above, and are all available 

at http://oehha.ca.gov/. 

 

119 U.S. EPA, Report of the Task Group of the Children’s Health Protection Advisory Comm. on America’s Children 

& the Env’t, 3d Ed. (2010).), 

http://yosemite.epa.gov/ochp/ochpweb.nsf/content/ACETask.htm/$file/ACE%20Task%20Group%20Report.pdf. 

120 Letter from Pamela Shubat, Chair, Children’s Health Protection Advocacy Council, CHPAC to Lisa Jackson, 

Administrator, U.S. EPA, (Oct. 21, 2010) (“CHPAC recommends that EPA staff scientists participating in the 

upcoming discussions bring the concern of early life stage exposure and sensitivity to the conversations that will 

take place concerning optimizing risk assessment practice.”), 

http://yosemite.epa.gov/ochp/ochpweb.nsf/content/CHPAC_NRC_Report.htm. 

121 U.S. EPA, Sci. Advisory Bd., Review of EPA’s draft entitled, “Risk and Technology Review (RTR) Risk 

Assessment Methodologies: For Review by the EPA’s Science Advisory Board with Case Studies – MACT I 

Petroleum Refining Sources and Portland Cement Manufacturing, EPA-SAB-10-007 (May 2010), at 7 (stating that 

“an overarching concern with the Agency’s chronic inhalation exposure estimates is that children’s exposures do not 

appear to have been adequately addressed”); see also id. at 34 n.13 (“In particular is the question of whether the 

interindividual variability factor for non-carcinogens and the standard cancer unit risk derivation adequately covers 

children. If it does not, it is a potentially significant uncertainty given the greater intake rate of children via 

inhalation and sensitivity to carcinogens and other toxicants.”).

122 Id. 
47

APPENDIX C: CHILD-SPECIFIC NON-CANCER CHART

Non-Cancer Health Risk:

Comparison of Cal. EPA OEHHA Child-specific health reference values

to U.S. EPA reference values

Chemical OEHHA 

Childhealth 

Reference 

Dose 

(chRD) or 

value*

U.S. EPA 

Chronic Oral 

Reference Dose 

(RfD)

Difference 

Between 

OEHHA and 

U.S. EPA

Order of 

Magnitude

Difference 

between 

OEHHA and 

U.S. EPA

Atrazine 0.006 0.035 6 1

Cadmium 0.000011 0.0005 (water) 45 1

0.001(food) 91 2

Chlordane 0.000033 0.0005 15 1

Chlorpyrifos 0.0001 0.0003 3 -

Deltamethrin 0.0001 0.01 100 2

Heptachlor 0.00003 0.0005 17 1

Heptachlor 

epoxide

0.000013 0.000013 1 -

Manganese 0.03 0.14 5 1

Methoxychlor 0.00002 0.005 250 2

Nickel 0.011 0.02 2 -

Pentachlorophe

nol

0.001 0.005 5 -

Lead

OEHHA 

action level*

EPA has not updated its action 

levels; CDC has reduced (2012).

1 (as a 

blood-level 

increase)

10 (5 - as a total) 10 (5 - as a total) 1

* All units are in mg/kg-day except lead which is in μg/dL blood. The lead value is not a 

dose. For lead this is a health benchmark indicating the increase in a child’s blood lead 

concentration showing protective action is needed.

Source: Office of Environmental Health Hazard Assessment (OEHHA), Cal. EPA

(Table of all child-specific reference doses finalized as of 06/22/09, 

http://oehha.ca.gov/public_info/public/kids/chrdtable.html)