National Emissions Standards for Hazardous Air 

Pollutants:

Flexible Polyurethane Foam Production

Summary of Public Comments and Responses on Proposed Rule 

(78 FR 66108, November 4, 2013)

U.S. Environmental Protection Agency

Office of Air Quality Planning and Standards

Sector Policies and Programs Division

Research Triangle Park, NC 27711
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Table of Contents

Page

Table of Contents...........................................................................................................................................i

List of Acronyms and Units of Measure.......................................................................................................ii

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

2. Summary of Public Comments................................................................................................................2

2.1. Risk Assessment................................................................................................................................3

2.2. Startup, Shutdown and Malfunction..................................................................................................8

2.3. Miscellaneous Comments..................................................................................................................9
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List of Acronyms and Units of Measure

ABA auxiliary blowing agent

AEGL acute exposure guideline levels 

ATSDR Agency for Toxic Substances and Disease Registry

CAA Clean Air Act

CEM continuous emissions monitor

CFR Code of Federal Regulations

CRWI Coalition for Responsible Waste Incineration

EPA Environmental Protection Agency

EJ environmental justice

EO executive order

ERPG Emergency Response Planning Guidelines 

FPUF flexible polyurethane foam

HAP hazardous air pollutants

HEM-3 Human Exposure Model, Version 1.1.0

HON Hazardous Organic NESHAP

LDAR leak detection and repair

MACT maximum achievable control technology

NACAA National Association of Clean Air Agencies

NCDENR North Carolina Department of Environment and Natural Resources

NESHAP National Emissions Standards for Hazardous Air Pollutants

PB-HAP hazardous air pollutants known to be persistent and bio-accumulative in the 

environment 

PFA Polyurethane Foam Association

ppm parts per million

REL reference exposure level 

RfC reference concentration

RTR residual risk and technology review

SAB Science Advisory Board

SIP state implementation plan

SSM startup, shutdown and malfunction

tpy tons per year

WWW world wide web
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1. Introduction

On November 4, 2013 (78 FR 66108), the U.S. Environmental Protection Agency (EPA) 

proposed to revise the National Emission Standards for Hazardous Air Pollutants (NESHAP) for 

Flexible Polyurethane Foam Production under the authority of section 112 of the Clean Air Act 

(CAA). This document presents summaries of the comments that were submitted in response to 

this action and our responses to those comments for all the comments not discussed in the 

preamble to the final rule. Within each comment summary, the EPA provides one or more 

Docket ID numbers for commenters who raised particular issues. However, the list of commenter 

ID numbers is not meant to be exhaustive. The EPA does not individually identify each and 

every commenter who made a certain point in all instances, particularly in cases where multiple 

commenters express essentially identical arguments. Although portions of the preamble to the 

final rule are paraphrased in this document, to the extent any ambiguity is introduced by 

paraphrasing, the preamble itself remains the definitive statement of the rationale for the final 

rule.

The comments to which we are responding were submitted in 8 letters from industry 

representatives, governmental entities, environmental advocacy groups, and citizens during the 

public comment period. In addition, the EPA received one comment letter from an industry 

group following the close of the comment period. Although the EPA is not required to respond to 

this late comment, to the extent practicable, the EPA often attempts to respond to late comments 

and our responses to the comments from this group are also presented in this document.

A list of the commenters, their affiliations, and the EPA docket number assigned to their 

correspondence is presented in Table 1-1. For simplicity, only the last four digits of the 

document numbers specific to each commenter are presented in this document (e.g., 0051, 

instead of EPA-HQ-OAR-2012-0510-0051). The EPA Docket contains all comment letters 

submitted and the comments are available for viewing at the EPA Docket Center Reading Room, 

or electronically through http://www.regulations.gov by searching Docket ID No. EPA-HQOAR-2012-0510 by docket number.
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Table 1. List of Commenters on 40 CFR Part 63 Subpart III, 

Proposed November 4, 2013 (78 FR 66108)

Docket No. 

EPA-HQOAR-2012-

0510 Commenter Name Affiliation

0051 Anonymous Not provided

0052 Nancy Jones North Carolina Dept. of Environment and Natural 

Resources (NCDENR)

0053 Shelia Holman North Carolina Dept. of Environment and Natural 

Resources (NCDENR)

0054 Robert H. Colby National Association of Clean Air Agencies

(NACAA)

0055 Jim Pew, Emma Cheuse Sierra Club

0056 Melvin Keener

Coalition for Responsible Waste Incineration

(CRWI)

0057 Natalie Varela Private citizen

0058 Robert Luedeka Polyurethane Foam Association (PFA)

0059

(late comment) Robert Luedeka Polyurethane Foam Association (PFA)

2. Summary of Public Comments

The following sections of this document summarize the public comments received on 

the proposal and present the EPA’s responses to those comments. The comment summaries are 

grouped by topic in Sections 2.1 through 2.4 as follows:

 Section 2.1–Risk Assessment 

 Section 2.2–Technology Review

 Section 2.3–Affirmative Defense and Startup, Shutdown, and Malfunction

 Section 2.4–Miscellaneous Comments

The comment summaries are numbered sequentially (1, 2, 3, etc.) throughout the 

document, regardless of section.
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2.1. Risk Assessment

1. Comment: Commenters 0052 and 0053–NCDENR reviewed the data used in the risk 

modeling and found a North Carolina facility included in the modeling database that should not 

have been included. The commenters stated that the Hickory Springs Manufacturing – Conover 

Complex facility is not a major source for HAP subject to 40 CFR part 63 subpart III but is an 

area source. Commenter 0052 provided the current facility operating permit to show that the 

facility is subject to 40 CFR part 63 subpart OOOOOO (the FPUF production and fabrication 

area source NESHAP) rather than 40 CFR part 63 subpart III. 

Response: We have reviewed the submitted information and agree that this facility is not 

subject to 40 CFR part 63 subpart III and does not need to be included in the modeling database 

for the flexible polyurethane foam (FPUF) production source category. We determined that it is 

not necessary to perform additional modeling with this revision, as this change would decrease 

emissions from the source category and would not affect the cost-effectiveness of the control 

measures considered. Thus, this change to the modeling database would not affect our decision 

that it is not necessary to revise the MACT standard for this source category pursuant to our 

review under CAA section 112(d)(6) and, to the extent it has any effect on our decision pursuant 

to CAA section 112(f)(2) that the existing standard provides an ample margin of safety, it would 

provide further support. 

2. Comment: Commenter 0054–NACAA recommends using potential or allowable 

emissions, rather than actual emissions in evaluating residual risk. The commenter expresses

concern with the use of actual emissions in parts of the risk analysis. The commenter argues that, 

since facility emissions could increase over time for a variety of reasons, the use of potential or 

allowable emissions is more appropriate. The commenter believes an analysis based on actual 

emissions from a single point in time could underestimate the residual risk from a source 

category. Further, the commenter notes that the major source HAP thresholds are based on 

potential-to-emit, as opposed to actual emissions, and air agencies issue permits based on 

potential emissions. According to the commenter, limiting the scope of a risk evaluation to actual 

emissions would be inconsistent with the applicability section of Part 63 rules. The commenter is

pleased to see that the EPA used allowable emissions in some areas of the rulemaking, but is

concerned that the EPA used actual emissions in parts of its risk analysis. Commenter 0054

encourages the EPA to use allowable emissions in the future, including in assessing acute health 

risks.

Response: Consistent with previous risk assessments, the EPA considers both allowable 

and actual emissions in assessing chronic risks under section 112(f)(2). (See, e.g., National 

Emission Standards for Coke Oven Batteries (70 FR 19998-19999, April 15, 2005); proposed 

and final National Emission Standards for Organic Hazardous Air Pollutants from the Synthetic 

Organic Chemical Manufacturing Industry (71 FR 34428, June 14, 2006, and 71 FR 76603, 

December 21, 2006). This approach is both reasonable and consistent with the flexibility 

inherent in the Benzene NESHAP framework for assessing acceptable risk and ample margin of 

safety. As a general matter, modeling allowable emission levels is inherently reasonable since 
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this reflects the maximum level sources could emit and still comply with national emission 

standards. But it is also reasonable to consider actual emissions, where such data are available, in 

acceptable risk and ample margin of safety. See National Emission Standards for Coke Oven 

Batteries, 70 FR 19992, 19998 (April 15, 2005). The commenter claims that limiting our review 

to actual emissions would be inconsistent with the applicability section of Part 63 rules. As 

explained, however, we did not limit our review to actual emissions. 

Finally, the commenter urges the Agency to rely on allowable emissions for purpose of 

our acute assessment. The use of allowable emissions was not considered due to the conservative 

assumptions used to gauge worst-case potential acute health effects. The conservative 

assumptions built into the screen include: (1) use of peak 1-hour emissions that are on average 

ten times the annual average 1-hour emission rates; (2) that all emission points experience peak 

emissions concurrently; (3) worst-case meteorology (from 1 year of local meteorology); and (4) 

that a person is located downwind at the point of maximum impact during this same 1­hour 

period. Thus, performing an acute screen based on allowable emissions would be overly 

conservative and at best, of questionable utility to decision makers.

3. Comment: Commenter 0054-NACAA states that the use of Acute Exposure Guideline 

Levels (AEGLs) or Emergency Response Planning Guidelines (ERPGs) in residual risk 

assessments is not appropriate and does not ensure that public health is adequately protected 

from the acute impacts of HAP exposure. These limits were developed for accidental release 

emergency planning and are not appropriate for assessing daily human exposure scenarios. In the 

December 2002 EPA document, "A Review of the Reference Dose and Reference Concentration 

Processes," EPA stated that the primary purpose of the Acute Exposure Guideline Level (AEGL)

program is to develop guidelines for once-in-a-lifetime, short-term exposures to airborne 

concentrations of acutely toxic chemicals. They are not meant to evaluate the acute impacts from 

routine emissions that occur over the life of a facility. Unlike the reference concentrations (RfCs) 

for chronic exposures, the AEGLs and ERPGs do not include adequate safety and uncertainty 

factors and cannot be relied upon to protect the public from the adverse effects of exposure to 

toxic air pollutants. The commenter supports the EPA’s increased reliance on the California 

Reference Exposure Levels (RELs) to address acute exposures in the residual risk assessments, 

and the commenter continued to urge EPA to use RELs for these assessments. 

Response: To better characterize the potential health risks associated with estimated

acute exposures to HAP, and in response to a key recommendation from the SAB’s peer review 

of the EPA’s RTR risk assessment methodologies,1 we generally examine a wider range of

available acute health metrics (e.g., RELs, AEGLs) than we do for our chronic risk assessments. 

This is in response to the SAB’s acknowledgement that there are generally more data gaps and 

inconsistencies in acute reference values than there are in chronic reference values. In some 

cases, when Reference Value Arrays2for HAP have been developed, we consider additional

 

1 11 The SAB peer review of RTR Risk Assessment Methodologies is available at: 

http://yosemite.epa.gov/sab/sabproduct.nsf/4AB3966E263D943A8525771F00668381/$File/EPASAB-10-007-

unsigned.pdf.

2 U.S. EPA. (2009) Chapter 2.9 Chemical Specific Reference Values for Formaldehyde in Graphical Arrays of 

Chemical-Specific Health Effect Reference Values for Inhalation Exposures (Final Report). U.S. Environmental 

Protection Agency, Washington, DC, EPA/600/R–09/061, and available on-line at 

http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=211003.
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acute values (i.e., occupational and international values) to provide a more complete risk 

characterization. As discussed in the preamble to the proposed rule (78 FR 66115), the exposure 

guidelines EPA considers depends on which exposure guidelines are available for the various 

hazardous air pollutants emitted by the relevant source category. The various guidelines that 

EPA may consider in assessing the potential for risks from acute exposures, include the 

California acute REL, and AEGL and ERPG values, 

4. Comment: Commenter 0054-NACAA notes that, in assessing the cancer risks related to 

the source category, EPA uses long-term concentrations affecting the most highly exposed 

census block for each facility. The commenter believes this analysis dilutes the effect of sources’ 

emissions by estimating the impact at the centroid of the census block instead of at the property 

line or wherever the maximum exposed individual is. Since census blocks can be large 

geographically, depending on the population density, the maximum point of impact can be far 

from the centroid, including at or near the property line where people may live or work. Further, 

the commenter notes, while it is possible that population distribution is homogenous over a 

census block, this assumption is not necessarily accurate in considering the predicted impacts 

from the location of a source. The commenter argues that using the Human Exposure Model-3 

(HEM-3), EPA can identify the maximum individual risk at any point in a census block that is 

within a 50-kilometer radius from the center of the modeled facility. Based on HEM-3’s power 

and ability, the commenter suggests that EPA abandon its use of the predicted chronic exposures 

at the census block centroid as surrogates for the exposure concentrations for all people living in 

that block. Rather, commenter 0054 recommends that EPA use the truly maximum individual 

risk, irrespective of its location in the census block, in its section 112(f)(2) risk assessments. 

With respect to the development of screening estimates of acute exposures and risk for noncancer health effects, the commenter is pleased that EPA did not focus on the centroid of the 

census blocks.

Response: As we have explained in previous RTRs, such as the Hazardous Organic 

NESHAP (HON) RTR (71 FR 76603, December 21, 2006), the EPA believes that, in a nationalscale assessment of lifetime inhalation exposures and health risks from facilities in a source 

category, it is appropriate to identify exposure locations where it may be reasonably expected 

that an individual will spend a majority of his or her lifetime. Further, in determining chronic 

risks, the EPA believes that it is appropriate to use census block information on where people 

actually reside, rather than points at the property line, to locate the estimation of exposures and 

risks to individuals living near such facilities. If a population did indeed live just outside of the 

property line of a facility, then it would result in a census block near the property line.

To estimate ambient concentrations for evaluating long-term exposures, the Human 

Exposure Model (HEM) uses the geographic centroids of census blocks as dispersion model 

receptors. The census block centroids are generally good surrogates for where people live within 

a census block. A census block generally encompasses about 40 people or 10-15 households. 

We agree with the commenter that in some cases where a census block is large the 

centroid may not be representative of the block’s residential locations. Risk estimates based on 

such centroids can be underestimated if there are residences nearer to a facility than the centroid, 

and overestimated if the residences are farther from the facility than the centroid. Although the 

 
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risk assessment documentation available in the docket for the proposal rule did not explain this 

aspect of our analysis, to avoid underestimating the maximum individual risk associated with a 

facility, we examined aerial images of all large census blocks within one kilometer of any 

emission source. (Experience from previous risks characterizations shows that in most cases the 

MIR is located within 1 km of the facility boundary.) If the block centroid did not represent the 

residential locations, we considered a location that better represented where people reside in that 

census block. If residential locations could not be represented by a single receptor (that is, the 

residences were spread out over the block), we added additional receptors for residences nearer 

to the facility than the centroid. 

For this source category, we added several receptors for census blocks where the centroid 

location was not representative of the residential locations. We have revised risk assessment 

documentation to provide additional information on these changes in Appendix 7 of the Residual 

Risk Assessment for the Flexible Polyurethane Foam Production Source Category.

Commenter 54 stated that they were pleased our acute and noncancer risk analyses do not 

focus on the centroid of the census blocks. This statement is correct for our acute analysis, which 

assumes a person is located downwind at the point of maximum impact, but no nearer to the 

source than 100 meters. However, chronic effects other than cancer are expressed in terms of the 

hazard quotient (HQ) for inhalation, which is calculated for each HAP at each census block 

centroid. As indicated above, in cases where we determined the centroid did not represent the 

residential area for a large census block, we added additional receptors to better represent 

residential locations.

5. Comment: Commenter 0054-NACAA and commenter 0057–private citizen believe 

improvements are needed in the EPA’s methods of evaluating environmental justice (EJ). 

Commenter 0057 notes that the analysis emphasizes the demographics of the nearby 

neighborhoods to these 13 manufacturers, and that the EPA identifies that there is a higher 

likelihood for African Americans to be within 3 miles of these sites. The commenter states that, 

since the EPA has determined that risks from this site are acceptable for all populations, the EPA 

claims it is not an environmental justice issue. The commenter argues that in order to better serve 

the purposes of Executive Order 12898 Federal Actions to Address Environmental Justice in 

Minority Populations and Low‐Income Populations, the EPA should conduct a more thorough 

Environmental Justice report than provided by Environmental Justice Review: Flexible 

Polyurethane Foam Production, and should identify the demographic characteristics of the most 

highly affected individuals or communities. The commenter also recommends that the EJ report 

provide the actual locations of the manufacturing sites, to demonstrate trends by regions or any 

interstate trends.

Commenter 0054 recommends that EPA conduct the demographic analysis on individuals 

projected to experience a facility-wide risk greater than 1-in-1-million and also on individuals 

living within five kilometers of the facility, regardless of projected risk, consistent with the 

approach used for the Hard and Decorative Chromium Electroplating and Chromium Anodizing 

Tanks source category. The commenter notes that EPA determined that the ratio of African 

Americans living within three miles (4.8 kilometers) of any source affected by this rule is 48 

percent higher than the national average. The commenter argues that EPA failed to address the 

disproportionate impact on African Americans even though the agency’s Interim Guidance on 

Considering Environmental Justice During the Development of an Action, states that the agency 

should consider addressing existing disproportionate impacts on minority, low-income, or 
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indigenous populations during rulemaking. Commenter 0054 also recommends that EPA rule 

writers work with the EPA Office of Environmental Justice to develop criteria and specific 

guidance on how to interpret and apply the outcome of these types of analyses in the rulemaking 

process.

Response: Under EO 12898, the EPA is directed to the greatest extent practicable and 

permitted by law, to make EJ part of its mission by identifying and addressing, as appropriate, 

disproportionately high and adverse human health or environmental effects of their programs, 

policies and activities on minority populations and low-income populations in the United States. 

Consistent with Executive Order (EO) 12898 and the Presidential Memorandum that 

accompanies it, the EPA’s EJ policies promote EJ by focusing attention and Agency efforts on 

addressing the types of environmental harms and risks that are prevalent among minority, lowincome and indigenous populations. EO 12898 and the Agency’s EJ policies do not mandate 

particular outcomes from an action, but they stipulate that decisions involving the action be 

informed by a consideration of EJ issues. 

As noted at proposal (78 FR 66123), we determine whether or not to conduct a 

demographics analysis considering a combination of factors, including the MIR, non-cancer 

TOSHI, population around the facilities in the source category and other relevant factors. For the 

FPUF production source category, our analyses show that actual emissions result in no 

individuals being exposed to cancer risk greater than 1-in-1 million, a non-cancer TOSHI greater 

than 1, or an acute HQ greater than 1. Therefore, no individuals experience high and adverse 

human health effects, regardless of whether those individuals are in minority, low-income or 

indigenous populations. However, we did conduct a proximity analysis to identify the 

demographic characteristics of the populations near FPUF production facilities, and the results of 

that analysis were considered in our rulemaking decisions. We also note that we are working 

with the Office of Environmental Justice in an ongoing effort to develop new tools for 

considering environmental justice in rulemakings. 

We thank the commenter for providing feedback that it would be helpful for the EJ report 

to include the manufacturing site locations. We have added a map of the FPUF locations to the

Final Environmental Justice Review: Flexible Polyurethane Foam Production document, and we 

will consider including similar information in future EJ documents.

6. Comment: Commenter 0059-PFA remarked that emissions from FPUF production 

facilities are not hazardous to area communities and population groups, and existing air emission 

data and worker health information collected by the commenter demonstrate that these facilities 

do not pose any environmental hazards to the surrounding community or the workforce. The 

commenter also noted that the facilities are subject to periodic air monitoring and do not have a 

history of compliance problems. Thus, the commenter believes that even without the proposed 

changes to the FPUF NESHAP, there are no environmental or health hazards associated with 

emissions from the FPUF production source category. 

Response: The EPA generally agrees with the commenter. Based on the results of our 

risk assessment for current actual emissions from the source category, we have determined that 

the risks from the FPUF production source category are acceptable and provide an ample margin 

of safety to protect public health and prevent an adverse environmental effect. The final 

amendments to the FPUF production NESHAP prohibiting the use of HAP or HAP-based 
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auxiliary blowing agents (ABAs), which are not currently used but were once widely used by the 

FPUF production industry, will ensure that no future emissions or risk increases occur due to 

these HAP. 

2.2. Startup, Shutdown and Malfunction

7. Comment: Commenter 0055-Sierra Club urges the EPA not to adopt the affirmative 

defense provisions. The commenter states that the affirmative defense provisions are unlawful 

and harmful. The commenter argues that 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, according to CAA 

section 304(b)(1)(B). The commenter observes that the CAA gives the EPA minimal discretion 

that only applies to administrative penalties which may be imposed under subsection 113(d), but 

no authority to compromise, modify or limit civil penalties that a court may impose under section 

113(e) or section 304. The commenter further states that the proposal will impermissibly chill 

citizen participation and the ability to win an effective, deterrent remedy in CAA enforcement 

actions. The commenter asserts that the burden the affirmative defense places on citizens makes 

it less likely that they will enforce the CAA. 

The commenter also states that if the EPA had the authority to promulgate any 

affirmative defense to penalties for malfunction, it should also promulgate strong reporting, 

monitoring, and other compliance measures, require a specific monetary penalty for each 

malfunction, and require that the affirmative defense cannot be used by a specific facility or 

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

In contrast, Commenter 0059 – PFA argues that the EPA has the authority to develop an 

affirmative defense, and the affirmative defense provides tools to ensure that future malfunctions 

do not occur or are corrected promptly if they do. The commenter points out that no systems, 

including emissions control systems, are perfect and that machinery malfunctions are unfortunate 

occurrences of everyday life in modern society. In support of the inclusion of an affirmative 

defense the commenter contends that: (1) the affirmative defense the EPA proposes provides the 

court discretion, as “the merits” of the affirmative defense “are independently and objectively 

evaluated in a judicial or administrative proceeding,” (2) the EPA proposes elements that a 

defendant must prove by a preponderance of the evidence to establish an affirmative defense, 

such as proving that the violation was caused by a “sudden, infrequent, and unavoidable failure 

of air pollution control, process equipment, or a process to operate in a normal or usual manner,” 

(3) a defendant who successfully establishes an affirmative defense is not permitted to continue 

emitting HAPs above the applicable emission threshold; and (4) the EPA is not charting new 

territory by establishing an affirmative defense for this rule, and the United States Court of 

Appeals for the Fifth Circuit recently upheld the EPA’s view that an affirmative defense 

provision is consistent with CAA section 113(e) (Luminant Generation Co. LLC v. United States 

EPA, 714 F.3d 841 (5th Cir. Mar. 25, 2013). 

A third commenter 0056-CRWI suggests several modifications to the affirmative defense 

provisions concerning the phrase “preponderance of evidence,” as is used in paragraph 

63.1290(e)(1); the use of the words “any” and “all”; the requirement for “properly signed, 

contemporaneous operating logs”; the definition of malfunction; and the formal root cause 

analyses. 
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Response: The EPA received several comments on the affirmative defense to civil 

penalties for violations caused by malfunctions that the EPA proposed to include in the rule. 

One commenter supported the affirmative defense. Two other commenters opposed the 

affirmative defense or various components of the affirmative defense. 

Recently, the United States Court of Appeals for the District of Columbia Circuit vacated 

an affirmative defense in one of the EPA’s Section 112 regulations. NRDC v. EPA, No. 10-1371 

(D.C. Cir. April 18, 2014) 2014 U.S. App. LEXIS 7281 (vacating affirmative defense provisions 

in Section 112 rule establishing emission standards for Portland cement kilns). The court found 

that the EPA lacked authority to establish an affirmative defense for private civil suits and held 

that under the CAA, the authority to determine civil penalty amounts in such cases lies 

exclusively with the courts, not the EPA. Specifically, the Court found: “As the language of the 

statute makes clear, the courts determine, on a case-by-case basis, whether civil penalties are 

‘appropriate.’” See NRDC, 2014 U.S. App. LEXIS 7281 at *21 (“[U]nder this statute, deciding 

whether penalties are ‘appropriate’ in a given private civil suit is a job for the courts, not EPA.”). 

The EPA is not including a regulatory affirmative defense provision in the final rule. In the event 

that a source fails to comply with an applicable CAA section 112 standards as a result of a 

malfunction event, the EPA’s ability to exercise its case-by-case-enforcement discretion to 

determine an appropriate response provides sufficient flexibility in such circumstances as is 

explained in more detail in the preamble to the final rule. Further, as the D.C. Circuit recognized, 

in an EPA or citizen enforcement action, the court has the discretion to consider any defense 

raised and determine whether penalties are appropriate. Cf. NRDC, 2014 U.S. App. LEXIS 7281 

at *24 (arguments that violation were caused by unavoidable technology failure can be made to 

the courts in future civil cases when the issue arises). The same is true for the presiding officer in 

EPA administrative enforcement actions. In light of the EPA’s decision not to include the 

affirmative defense in the final rule, we are not responding to the comments opposing the 

affirmative defense or to comments recommending revisions to a regulatory affirmative defense 

provision. With respect to comments that supported the affirmative defense the preamble to the 

final rule explains in detail the EPA’s reasons for not including an affirmative defense provision 

in the final rule. 

2.3. Miscellaneous Comments

8. Comment: Commenter 0058 PFA - The PFA agrees with the review and 

recommendations of the EPA concerning the effectiveness of the initial MACT standard and that 

further controls to reduce residual risks are unnecessary. The commenter also concurs with the 

EPA's proposal to add an affirmative defense to civil penalties for violations of emission 

standards that are caused by equipment malfunctions and commends the EPA for recognizing 

that, in spite of diligent efforts to properly maintain equipment, emission standards may be 

violated under circumstances beyond the control of the source. Commenter 0057 – Private 

Citizen supports the proposed prohibition of the use of HAP or HAP based ABAs and the 

requirements for periods of startup, shutdown and malfunction. 

Response: We acknowledge the commenters’ support for the EPA’s proposed rule 

requirements. We discuss the affirmative defense in our responses in section 2.2 of this 

document. 
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9. Comment: Commenter 0051- Anonymous states that the NSPS and MACT regulations 

should have explicit requirements for the types of activities that would trigger a recertification of 

continuous emissions monitors (CEMs). The commenter suggests requirements similar to the 40 

CFR Part 75 CEM requirements, such as CEM replacement, sampling line replacement, major 

CEM components, etc. should be used. The commenter adds that the regulation should state how 

data collected from a CEM should be handled from the time period the "upgraded" CEM was 

restarted until it was re-certified (e.g., data reported as downtime or good data, how exceedances 

should be handled). 

Response: The FPUF MACT standards do not include CEM requirements; therefore, the 

commenter’s remarks are beyond the scope of this rule.