Summary of Public Comments and Responses for the Risk and Technology Reviews for Surface Coating of Metal Cans and Surface Coating of Metal Coil National Emission Standards for Hazardous Air Pollutants

December 17, 2019

Summary of Public Comments and Responses for the Risk and Technology Reviews for Surface Coating of Metal Cans and Surface Coating of Metal Coil NESHAP

                     U. S. Environmental Protection Agency
                 Office of Air Quality Planning and Standards
                Sector Policies and Programs Division (D243-02)
                 Research Triangle Park, North Carolina 27711

The primary contact regarding questions or comments on this document is:

Paula Hirtz<PHONE_NUMBER><EMAIL_ADDRESS>U.S. Environmental Protection Agency
OAQPS/Sector Policies and Programs Division (D243-02)
Research Triangle Park, North Carolina 27711

                               TABLE OF CONTENTS

                                                                           Page
1.0	Introduction	1
2.0	List of Commenters	2
3.0	General Support for the Proposed Actions	3
4.0	Risk Modeling and Determination	3
5.0	Technology Reviews	27
6.0	Electronic Reporting Provisions	30
7.0	Startup, Shutdown, Malfunction (SSM) Provisions	40
8.0	Test Methods and Ongoing Emissions Compliance Demonstrations Requirement	42
9.0	Proposed Compliance Dates	45

List of Acronyms and Abbreviations

AEGL	Acute Exposure Guideline Levels
AERMOD	American Meteorological Society/EPA Regulatory Model
ATSDR	Agency for Toxic Substances and Disease Registry
CAA	Clean Air Act
CalEPA	California Environmental Protection Agency
CDX	Central Data Exchange
CEDRI	Compliance and Emissions Data Reporting Interface
CFR	Code of Federal Regulations
DNA	deoxyribonucleic acid
EPA	U. S. Environmental Protection Agency
ERPG	Emergency Response Planning Guidelines
FQPA	Food Quality Protection Act
FR	Federal Register
HAP	Hazardous Air Pollutant
HEM	Human Exposure Model
HON	Hazardous Organic NESHAP
HQ	hazard quotient
IRIS	Integrated Risk Information System
MACT	Maximum Achievable Control Technology
MIR	Maximum Individual Risk
MOA 	mode of action
NAS	National Academy of Sciences
NESHAP	National Emission Standards for Hazardous Air Pollutants
NRC	National Research Council
OAQPS	Office of Air Quality Planning and Standards
OEHHA	California's Office of Environmental Health Hazard Assessment
PB-HAP	persistent and bioaccumulative HAP
REL	CalEPA Reference Exposure Level
RfC	Reference Concentration
RfD	Reference Dose
RTR	Residual Risk and Technology Review
SAB	Science Advisory Board
SSM	startup, shutdown, and malfunction
TOSHI	Target Organ-Specific Hazard Index
UF	Uncertainty Factor
U.S.C.	United States Code

Introduction
On June 4, 2019, the Environmental Protection Agency (EPA) proposed revisions to the National Emission Standards for Hazardous Air Pollutants (NESHAP) for two source categories in a single Federal Register (FR) notice:
Surface Coating of Metal Cans (40 Code of Federal Register (CFR) part 63, subpart KKKK); and
Surface Coating of Metal Coil (40 CFR part 63, subpart SSSS).
Some of the more significant comments and responses appear in the single preamble for the action for both final rules. This document contains summaries of all the public comments that the EPA received on the proposed standards (comments that are summarized and addressed in the preamble to the proposed rule are also summarized in this document for completeness). Copies of all comment letters submitted to the EPA on the proposed rulemaking are available at the EPA Docket Center Public Reading Room. Comment letters are also available electronically through http://www.regulations.gov by searching for the following dockets:
Docket ID No. EPA-HQ-OAR-2017-0684 for subpart KKKK; and
Docket ID No. EPA-HQ-OAR-2017-0685 for subpart SSSS.

List of Commenters
The EPA received five unique comment letters after June 4, 2019 on the proposed revisions to the NESHAP for the proposed residual risk and technology reviews (RTRs) and proposed amendments. Two of the five comment letters were submitted to both Docket ID No. EPA-HQ-OAR-2017-0684 and Docket ID No. EPA-HQ-OAR-2017-0685. The commenter, affiliation, and item number are listed in Table 2-1. The two letters that were submitted to both dockets are identified in the remainder of this document by their entry in Docket ID No. EPA-HQ-OAR-2017-0684 for convenience.
Table 2-1. Public Comments Received after the RTRs for Surface Coating of Metal Cans and Surface Coating of Metal Coil
Metal Can Docket Number
Metal Coil Docket Number
Commenter and Affiliation
EPA-HQ-OAR-2017-0684-0043
                                       -
Anonymous
                                       -
EPA-HQ-OAR-2017-0685-0045
Anonymous
EPA-HQ-OAR-2017-0684-0044 (letter) and -0045 (attachments)
EPA-HQ-OAR-2017-0685-0046 (letter) and -0047 (attachments)
Emma Cheuse,
Earth Justice on behalf of California Communities Against Toxics and Sierra Club
                                       -
EPA-HQ-OAR-2017-0685-0048
Curt Wells,
Senior Director of Regulatory Affairs, The Aluminum Association
EPA-HQ-OAR-2017-0684-0046
EPA-HQ-OAR-2017-0685-0049
Sylvester A. Giustino, Director of Government Relations and Technical Affairs, Can Manufacturers Institute (CMI)

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General Support for the Proposed Actions
3.1 Comment: One commenter (0685-0045) expressed general support for the regulation of HAP emissions from the surface coating of metal cans and metal coils.
3.1 Response: The EPA acknowledges the commenter's support.
Risk Modeling and Determination
4.1 Comment: One commenter (0684-0046) supported the EPA's decision, based on the Agency's risk modeling, not to make any revisions to the numerical emission limits contained in the current NESHAP for the Surface Coating of Metal Cans. One commenter (0685-0048) supported the EPA's decision, based on the Agency's risk modeling, not to require additional controls or to make any revisions to the numerical emission limits contained in the current NESHAP for the Surface Coating of Metal Coil.
4.1 Response: The EPA acknowledges the commenter's support.
4.2 Comment: One commenter (0684-0044) disagreed with the EPA's determination that the public health risk posed by these source categories after implementation of MACT is acceptable because the EPA underestimated risks from acute exposures by relying on inappropriate AEGL and ERPG risk benchmarks rather than the correct REL values. The commenter stated that the AEGLs and ERPGs are designed only for emergency exposure response and cannot be considered health protective for community members facing potentially repeat exposures over a lifetime to emission spikes.  The commenter contended that RELs are the appropriate metric to use because they represent the best peer-reviewed science of acute community health effects. The commenter concluded that the EPA is underestimating acute risks by using inappropriate health reference values.
4.2 Response: The dose-response values the EPA considers for acute screening analyses depend on which acute dose-response values are available for the HAP emitted. The EPA uses available acute RELs, AEGLs, and ERPGs to screen for potential acute health hazards. Small quantities of 1,3-butadiene, benzene, and nickel emissions were reported for the Metal Coil source category. Based on the EPA's examination of the acute RELs for these HAP, including the methodology used in the derivation of the values (e.g., application of uncertainty factors, effect upon which the value is based), we have determined that they are not appropriate for the EPA's residual risk reviews. For additional discussion of this topic refer to the response to Comment 4.10 and the Metal Coil Risk Assessment Report in the Surface Coating of Metal Coil Docket for this action.

It is often the case that all the different types of acute dose-response values are not available for a given HAP. In these instances, the EPA describes the potential acute health hazard in relation to the acute dose-response values that are available. Importantly, when interpreting the results, we are careful to identify the dose-response value being used and consider the potential health implications associated with any specific dose-response value being exceeded.

For the acute screening assessments, we use the health protective assumptions that every process releases its peak hourly emissions at the same hour, that the worst-case dispersion conditions occur at that same hour, and that an individual is present at the location of maximum HAP concentration for that hour. In addition, an AEGL-1 is established to protect the general population, including susceptible individuals, from discomfort, irritation, or certain asymptomatic nonsensory effects  -  effects that are not disabling and are transient and reversible. An ERPG-1 is the maximum airborne concentration below which nearly all individuals could be exposed for up to 1 hour without experiencing more than mild, transient health effects or without perceiving an objectionable odor. The EPA only uses the AEGLs and ERPGs for acute 1-hour inhalation screening assessments. We do not use AEGLs and ERPGs to assess repeat exposures over a lifetime or long-term exposures. Additional information on our acceptability determination is provided in the response to Comment 4.4 below.
4.3 Comment: One commenter (0684-0044) disagreed with the EPA's conclusion that a hazard quotient (HQ) of 3, which is three times the EPA benchmark of 1, represents an acceptable exposure. As the commenter explained, the EPA justified that an HQ of 3 in this case represents an acceptable risk because the acute risk estimates are "intentionally biased high and are thus, health protective." According to the commenter, the EPA concluded that the estimated risks are biased high because the estimate assumes that a person is exposed to the highest hourly emissions from each emission point in the source category simultaneously with worst-case meteorological conditions. The commenter objected to the EPA's rationale, stating that the EPA has no basis for concluding that these conditions will not occur. Therefore, the commenter maintains that the EPA's conclusion of acceptable acute risk is legally invalid because it ignores the peak HAP exposures that can occur.
4.3 Response: When one or more HQ is above 1, the EPA evaluates additional information (e.g., proximity of the facility to potential exposure locations) to determine whether there is a potential for significant acute risks. In this action the commenter is referring to the acute screening analysis for Metal Coil that resulted in a maximum acute noncancer HQ of 3 (based on the REL) for diethylene glycol monobutyl ether (DGME). As indicated in the proposal, the worst-case conditions include the assumption that a person is located at the point of maximum exposure during the time when peak emissions and worst-case dispersion conditions occur simultaneously. While it is true that we cannot say with 100% certainty that these conditions could not occur simultaneously, it is highly unlikely. For example, DGME emissions from this facility come from three separate processes (coating application, solvent mixing, and "other") and 15 separate stacks. It is very unlikely that the highest hourly emissions of DGME would occur at these three separate processes and 15 stacks at the same time. In addition, as shown in the Residual Risk Document for Metal Coil (Appendix 10, Figure 1) the DGME HQ of 3 occurs on a rail line and a public roadway.  The chance of someone being in these locations for an hour during the worst hour of emissions and the worst hour of dispersion conditions is remote. The highest DGME HQ at a residential location is 1. In addition, we indicated in the proposal preamble that, since there is not a specified acute dose-response value for DGME, we applied the most protective dose-response value from the other glycol ether compounds, the acute REL for ethylene glycol monomethyl ether, to estimate risk. Given that ethylene glycol monomethyl ether is more toxic than other glycol ethers, the use of this surrogate is a health-protective choice in the EPA's risk assessment.

Thus, as discussed in the Metal Coil Risk Assessment Report in the docket for this action, by assuming the co-occurrence of independent factors for the acute screening assessment, the results are intentionally biased high and are thus health protective. We conclude that adverse effects from acute exposure are not anticipated due to emissions from this source category.

4.4 Comment: One commenter (0684-0044) asserted that the EPA's benchmark on what level of health risk is acceptable is an outdated policy inappropriately anchored in determinations made in 1988, which do not reflect subsequent scientific breakthroughs and public perceptions of acceptable environmental health risks. The commenter disagreed with the EPA's policy that a cancer risk of 100-in-1 million is presumed to be either safe or acceptable, that for acute risks an HQ less than 1 is always acceptable, and that an HQ greater than 1 can be deemed acceptable without reasoned explanation. The commenter stated that the EPA's benchmark policy is based on a 1988 study of people's tolerance for various types of health risk, known as the Survey of Societal Risk.  The commenter claims that the EPA has failed to revisit or update this policy over the decades, 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 ways to analyze and control the impacts of pollutants on human health. The commenter listed 17 so-called "landmark" actions since 1990 by the EPA and scientific bodies relating to environmental health effects and human susceptibility (see page 13 of comment letter (0684-0044)), which the commenter states should make the current EPA policy outdated. The commenter asserts that the EPA policy needs reform in the face of increasing evidence that challenges that assumption of a safe or acceptable level of HAP exposure.
4.4 Response: As indicated in the proposal preamble, for source categories subject to MACT standards, section 112(f)(2) of the CAA requires the EPA to determine whether promulgation of additional standards is needed to provide an ample margin of safety to protect public health or to prevent an adverse environmental effect. Section 112(f)(2)(B) of the CAA further expressly preserves the EPA's use of the two-step approach for developing standards to address any residual risk and the Agency's interpretation of "ample margin of safety" developed in the National Emissions 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 (Benzene NESHAP) (54 FR 38044, September 14, 1989). The EPA notified Congress in the Risk Report that the Agency intended to use the Benzene NESHAP approach in making CAA section 112(f) residual risk determinations (EPA - 453/R - 99 - 001, p. ES - 11). The EPA subsequently adopted this approach in its residual risk determinations and the United States Court of Appeals for the District of Columbia Circuit (the Court) upheld the EPA's interpretation that CAA section 112(f)(2) incorporates the approach established in the Benzene NESHAP into the Act. See NRDC v. EPA, 529 F.3d 1077, 1083 (D.C. Cir. 2008). Thus, the comment is not consistent with the statute when taking issue with the 1988 approach.
The approach incorporated into the CAA and used by the EPA to evaluate residual risk and to develop standards under CAA section 112(f)(2) is a two-step approach. In the first step, the EPA determines whether risks are acceptable. This determination "considers all health information, including risk estimation uncertainty, and includes a presumptive limit on maximum individual lifetime [cancer] risk (MIR) of approximately 1 in 10 thousand." 54 FR 38045, September 14, 1989. If risks are unacceptable, the EPA must determine the emissions standards necessary to reduce risk to an acceptable level without considering costs. In the second step of the approach, the EPA considers whether the emissions standards provide an ample margin of safety to protect public health "in consideration of all health information, including the number of persons at risk levels higher than approximately 1 in 1 million, as well as other relevant factors, including costs and economic impacts, technological feasibility, and other factors relevant to each particular decision." Id. The EPA must promulgate emission standards necessary to provide an ample margin of safety to protect public health or determine that the standards being reviewed provide an ample margin of safety without any revisions. After conducting the ample margin of safety analysis, we consider whether a more stringent standard is necessary to prevent, taking into consideration costs, energy, safety, and other relevant factors, an adverse environmental effect.
We continue to use the statutorily mandated risk decision framework as outlined above, however we continually update our risk assessment methods to reflect current science. Specifically, we update our methods to: reflect advancements in data availability, incorporate modeling updates, use updated health dose-response values, to improve efficiency, and to improve the quality of our results.  We periodically seek SAB's review of our new or improved risk assessment methods. Most recently, in 2017/2018 we requested that SAB review updates to our multipathway screening assessment, environmental screening assessment, and several new tools for our inhalation risk assessment (receptor check tool and urban/rural tool). In SAB's final report, they stated "The SAB finds that the overall methodology and specifically the revisions since 2009 are for the most part appropriate and improve the assessment capabilities; opportunities for improvement are documented in SAB's report." We are currently evaluating SAB's recommendations and plan to implement those that are technically feasible as resources allow.
Regarding our assessment of acute risks and the use of the hazard quotient in our acceptability determination, we explained in the proposal preamble, for acute screening analyses we examine a wide range of available acute health metrics. This is in acknowledgement that there are generally more data gaps and uncertainties in acute reference values than there are in chronic reference values. By definition, the acute REL represents a health-protective level of exposure, with effects not anticipated below those levels, even for repeated exposures; however, the level of exposure that would cause health effects is not specifically known. As the exposure concentration increases above the acute REL (i.e., REL HQ is above 1), the potential for effects increases. Therefore, when an REL is exceeded (i.e., REL HQ is above 1) and an AEGL-1 or ERPG-1 level is available (i.e., levels at which mild, reversible effects are anticipated in the general population for a single exposure), we typically use them as an additional comparative measure, as they provide an upper bound for exposure levels above which exposed individuals could experience effects.
4.5 Comment: One commenter (0684-0044) charged that the proposed rulemaking violates section 112(f) of the CAA because it fails to assess public health beyond its determination of acceptable risk and never explains how the proposed standards provide an ample margin of safety to protect public health. The commenter stated that EPA's rationale that it investigated available emission control options and did not identify control measures that had not been previously considered during development of the original NESHAP does not satisfy the "ample margin" requirement. The commenter alleged that this rationale shows no consideration of a margin of safety at all, but simply a duplicative reliance on its technology review. The commenter pointed out that EPA's own record shows various alternative coatings and that work practices would indeed reduce emissions and thus health risks, for metal coil sources.  While these emission controls do not apply to all of the emission units covered by the existing standards, the commenter pointed out that they do apply to some and, therefore, would reduce emissions and health risks. The commenter stated that EPA's attempt to rely on the technology review, designed to satisfy section 112(d)(6) of the CAA, as a justification not to strengthen the standards to protect public health under section 112(f)(2) is unlawful and arbitrary. The commenter stated that these are separate statutory tests and obligations that EPA may not lawfully collapse into one; citing that the D.C. Circuit explained, these are "two distinct, parallel analyses: a recurring `technology review' under section 112(d)(6) and a one-time `risk review' under section 112(f)(2)." Nat'l Ass'n of Surface Finishing v. EPA, 795 F.3d 1, 5 (D.C. Cir. 2015). The commenter concluded that EPA may not use the technology review findings to avoid satisfying the requirement to provide an ample margin of safety to protect public health.
4.5 Response: The EPA does not agree that the ample margin of safety analyses for the Metal Can and Metal Coil source categories are insufficient. The risk assessments demonstrated that health risks due to air emissions from the surface coating of metal cans and metal coil sources are acceptable. In considering whether the standards should be tightened to provide an ample margin of safety to protect public health, we consider the same risk factors that we consider for our risk acceptability determination and also consider the costs, technological feasibility, and other relevant factors related to emissions control options that might reduce risk associated with emissions from a source category. Since the baseline risks were low for both source categories, little risk reduction could be realized regardless of the availability of further control options. Therefore, given the low baseline risks, the large margin between the estimated risk levels and levels that would be indicative of significant public health risk, and lack of options for further risk reductions, we proposed that additional emission controls for these source categories were not necessary to provide an ample margin of safety.

We do not agree that it is unreasonable to use the same facts and analyses to support both the ample margin of safety analysis and the technology review to the extent that the same information is relevant to both actions. In this case, the availability of controls is relevant to both rules so EPA acted reasonably by using the same information to support both the residual risk reviews and the technology reviews.

As discussed in detail in the response to comment 5.2, as part of the technology reviews the EPA reviewed the coatings (solvent borne as well as alternative coatings) currently used by these source categories and any advancements in the coatings, the HAP control requirements in NESHAP for similar coating source categories and application of those controls to the metal cans and metal coil source categories, state and local HAP control requirements in facility operating permits and application of those controls to the metal cans and metal coil source categories, and work practices and housekeeping measures currently used by these source categories and any advances that were applicable to these source categories. As discussed in the technology review memos and the proposal preamble, for the Metal Can source category, the only development identified in the technology review was the ongoing development and the potential future conversion from conventional interior can coatings that contain bisphenol A (BPA) to interior coatings that do not intentionally contain BPA (BPA - NI). Since BPA and BPA - NI are not HAP, this change would have no effect on the HAP emissions. For the Metal Coil source category, the only development identified in the technology review was the ongoing development and the potential future conversion of strontium chromate coatings to trivalent chromium coatings. There were no other technological developments identified that affect HAP emissions for the Surface Coating of Metal Cans or the Surface Coating of Metal Coil source categories. For these reasons, the EPA is not revising its conclusions on the ample margin of safety analyses for these categories.

4.6 Comment: One commenter (0684-0044) contended that the EPA's risk analysis significantly underestimates emissions because the risk analysis is based primarily on emissions from the 2014 National Emission Inventory (NEI) which was largely calculated from emission factors and industry's judgment, which: (1) incorporate the erroneous assumption that equipment is operating as designed under normal conditions, and (2) do not account for environmental variables that significantly impact emissions (e.g., wind speed, which can have a substantial impact on emissions from certain sources). The commenter also stated appreciation that the EPA had conducted an information collection request for one category and site visits but argued that the EPA did not collect current emission test data.
The commenter (0684-0044) stated that it is well-documented that emission factors underestimate emissions for a variety of reasons including inherent bias in the factors themselves and the inability to account for equipment malfunctions and environmental conditions. The commenter argued that the agency must adjust the emissions inventory using these same conclusions from the technology review and the large body of scientific evidence, which show that emissions factors underestimate emissions, in order to ensure that the inventory better represents reality and reflects actual emissions. The commenter provided the example of the EPA's Office of the Inspector General, which has stated that "[t]he heavy use of emission factors in the [national emissions inventory] makes the reliability of the data highly uncertain. Emission factors can result in emissions data of questionable reliability...."
The commenter (0684-0044) stated that the tests used to develop emission factors are intentionally conducted on new equipment operating under normal conditions because emission factors are formulas that attempt to estimate long-term average emissions, quoting an EPA document: "[s]ources often are tested more frequently when they are new and when they are believed to be operating properly, and either situation may bias the results." The commenter further pointed out that the EPA itself notes that "[p]arameters that can cause short-term fluctuations in emissions are generally avoided in testing and not taken into account in test evaluation."
The commenter (0684-0044) stated that the emissions from startup, shutdown, and malfunction (SSM) events can be significant, as EPA has acknowledged, and because emission factors incorporate the assumption that equipment is functioning as designed under normal conditions, emissions produced during SSM events are not accurately represented in reported emissions, which does not account for (1) the emissions that are generated during upset and SSM events, nor (2) the increased emissions that result from poor maintenance of equipment. The commenter argued that, in this way, the EPA has failed to account for the significant emissions produced during SSM upset events or increased emissions that result from poor equipment maintenance, which results in grossly inaccurate, unreliable, and biased emissions data for these sources.
4.6 Response: The EPA disagrees with the commenter that it primarily used the 2014 NEI in these risk analyses and with the statement that an information collection request was conducted for one source category in this action. In the proposal preamble (84 FR 25935) the EPA states it primarily used the 2011 NEI and supplemented this emissions data with data from the 2014 NEI and states that no formal information collection request was conducted for this action. These comments do not appear to be relevant to these source categories. In addition, the EPA disagrees with commenter claims that the emissions are underestimated because the inventories were not based on emission factors and industry judgement as the commenter suggests. Instead the NESHAPs require the estimation of organic HAP emissions from surface coating operations by using mass balance methods. In the mass balance method, the reporter assumes that all organic HAP contained as solvents in the coatings evaporate and are emitted to the atmosphere unless the facility is using an add-on control device. If a facility is using an add-on control device, the NESHAP requires the application of the add-on control device destruction efficiency factor to the emissions. The NEI reflects the resulting emission estimates based on these mass balance and destruction efficiency calculations, as required by the NESHAP. The facility is also required to establish operating limits and monitor the device and comply with operating limits to ensure it maintains the same efficiency as during the performance test.
These mass balance methods of estimating HAP emissions are based simply on the amount of HAP solvent consumed in the coatings. If different amounts of solvent were used, for example, to adjust coating viscosity to account for different coating application and drying conditions, then this would still be reflected in the mass balance calculations. The new requirement to test the control equipment once every five years will further ensure the operating limits are met and the equipment is operating properly. In addition, the EPA risk model HEM-AERMOD ensures that meteorological conditions such as wind speed are taken into account as part of the risk assessment.
We also disagree with the commenter's assertions regarding emissions during SSM events as they apply to the emission inventories for these source categories. Because these inventories are based on mass balance accounting of the organic HAP consumed as solvents, those consumption data inherently include any HAP that were emitted as a result of a malfunction event. Furthermore, as we discussed in the preamble to the proposed rule (85 FR 25926), emissions are not likely to increase during malfunction events for these source categories because a malfunction would not, for example, increase the HAP content of the coatings being applied. In the event of a control device malfunction, which results in a deviation from the operating limits, the NESHAP requires the facility to take corrective action to minimize emissions. Corrective actions may include ceasing the coating operation until the control device can be repaired to continue normal operation. In such a case, the excess HAP emissions should be minimal because the coating operation can be shut down quickly.
Because the emission inventories used for the risk analysis for these surface coating categories are not based on emission factors and engineering judgement, the comments regarding whether the development of emission factors is based on representative data are not relevant to these source categories.
4.7 Comment: One commenter (0684-0044) stated that EPA must assess the health risk posed by periods of startup, shutdown, malfunction (SSM), or process upsets. The commenter stated that failing to account for emission spikes from these events will underestimate risks. The commenter further stated that EPA could use statistical methods and probability factors to estimate health risks, and pointed out that EPA has at least once assessed chronic and acute risk from non-routine emission in the 2015 Petroleum Refinery Sector Rule (Final Residual Risk Assessment for the Petroleum Refining Source Sector, EPA-HQ-OAR-2010-0682-0800 at page 35 and Appendix 13).
4.7 Response: We disagree with the commenter that emissions events in violation of the standards, whether or not they are caused by malfunction events, should be considered as part of the risk analysis. The EPA interprets CAA section 112 as not requiring emissions that occur during periods of malfunction to be factored into development of CAA section 112 standards and this reading has been upheld as reasonable by the Court in U.S. Sugar Corp. v. EPA, 830 F.3d 579, 606 - 610 (D. C. Cir. 2016). Moreover, the purpose of the risk review is to evaluate whether the emission limits -- the "standards promulgated pursuant to subsection (d)," not the non-compliance with those standards [CAA section 112(f)(2)(A)] -- should be made more stringent to reduce the risk posed after compliance with the underlying maximum achievable control technology (MACT) standard. To the extent that a source is exceeding the emissions limits in the underlying MACT standard due to malfunctions, no tightening of the emission standard under the residual risk review will avoid or mitigate against such exceedances. In other words, a source that is exceeding the MACT emissions standard promulgated under CAA section 112(d) would not be any more likely to be able to avoid such exceedances and comply with a different, presumably more stringent, standard promulgated under CAA section 112(f). With the removal of the SSM exemptions in this final rule, these exceedance events are now violations and subject to enforcement by the EPA, the states or citizens, and an action for injunctive relief is the most effective means to address violations, whether or not they are caused by malfunctions, if an emissions event poses a significant health or environmental risk.
The situation with the 2015 Petroleum Refinery Sector Rule is not comparable to either the Metal Can NESHAP or the Metal Coil NESHAP. As explained in Appendix 13 to the Final Residual Risk Assessment for the Petroleum Refining Source Sector, the Petroleum Refinery Sector Rule allows for a certain number of pressure relief and flare events per year. Therefore, the EPA performed an assessment of the acute risks associated with those events using data collected from refinery sector facilities for actual events. Neither the Metal Can NESHAP nor the Metal Coil NESHAP have an allowance for comparable non-routine events. Furthermore, as noted above, a malfunction will not increase the level of HAP emitted for any source using compliant coatings without add-on controls and facilities can cease coating quickly if a control device malfunctions, thereby significantly limiting excess emissions from these source categories.  For these reasons, we do not agree that emissions from potential malfunction events should be considered in the risk review for these source categories.
4.8 Comment: One commenter (0684-0044) argued that, as part of the residual risk assessment for each source category, the EPA unlawfully and arbitrarily failed to assess the health risks for "the individual most exposed to emissions" from each of the source categories, as § 7412(f)(2) requires. The commenter stated that the EPA has chosen an arbitrary point, a census-block centroid, without demonstrating that this is equivalent to the maximum exposed person. The commenter expressed concern that the EPA's method ignores the fact that people may live nearer the fence-line than the centroid of the census block, is not scientific or lawful, would not be reproducible, and that application would vary should a different risk assessor conduct modeling on an individual facility. The commenter argued that the EPA must have verification metrics in place to ensure that it assesses health risks based on the actual or likely locations of specific receptors representative of those living near the facility and/or who are the people most exposed to a source or source category.
The commenter (0684-0044) stated that taking geographic variation out of the equation fails to properly account for exposure to the "individual most exposed to emissions" as required by section 7412(f)(2)(A) and fails to provide an accurate accounting of risks. The commenter continued that estimating the annual average concentrations at the area-weighted centers of census blocks blatantly and artificially underestimates the risk estimated for people at the fence-line since the center of a census block is almost always further away from the facility than the fence-line. The commenter continued that census blocks vary greatly in size, especially outside of large urban areas, yet EPA provides no evidence that it reviewed census block size or configuration to consider how concentrations of pollutants might vary within these blocks. The commenter concluded that area-weighted centers of census blocks likely significantly underestimate exposure in some cases, and by failing to assess health risks for the most-exposed person (rather than just by the middle of a census block), the EPA violates this provision.
The commenter (0684-0044) argued that the EPA's failure to adjust receptor points for residents living on the fence-line is particularly inexcusable given that the HEM-AERMOD model allows for such an adjustment, and that such an adjustment was appropriately made for the estimation of acute health risks. The commenter continued that having recognized that the maximum exposed individual for acute risks is likely present at the fence-line, EPA cannot justify failing to analyze cancer and other chronic health effects in a similar manner.
4.8 Response: The EPA disagrees with the commenter. In a national-scale 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. In determining chronic risks, 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. Census blocks are the finest resolution available as part of the nationwide population data (as developed by the U.S. Census Bureau); on average, a census block is comprised of approximately 40 people and about 10 households. In the EPA risk assessments, the geographic centroid of each census block containing at least one person is used to represent the location where all the people in that census block live. The census block centroid with the highest estimated exposure then becomes the location of maximum exposure, and the entire population of that census block is assumed to experience the maximum individual risk (MIR). In some cases, because actual residence locations may be closer to or farther from facility emission points, this may result in an overestimate or underestimate of the actual annual concentrations (although there is no systematic bias for average levels). Given the relatively small dimensions of census block in densely populated areas, there is little uncertainty introduced by using the census block centroids in lieu of actual residence locations. There is the potential for more uncertainty when the census blocks are larger, although there is still no systematic bias. The EPA concludes that the most appropriate locations at which to estimate chronic exposures and risks are the census block centroids because: 1) census blocks are the finest resolution available in the national census data; 2) facility fence-lines do not typically represent locations where chronic exposures are likely (i.e., people do not typically live at the fence-line of facilities); and 3) there is no bias introduced into the estimate of MIR by using census block centroid locations. In its peer review of the methodologies used to estimate risks as part of the RTR rulemaking efforts, the EPA's SAB endorsed this approach.
In addition to the approach described above, the EPA recognizes that where a census block centroid is located on industrial property or is large and the centroid is less likely to be representative of the block's residential locations, the block centroid may not be the appropriate surrogate. For these source categories (as described in Residual Risk Assessment for the Surface Coating of Metal Cans Source Category (Docket ID No. EPA - HQ - OAR - 2017 - 0684) and Residual Risk Assessment for the Surface Coating of Metal Coil Source Category (Docket ID No. EPA - HQ - OAR - 2017 -  0685), in cases where a census block centroid was within 300 meters of any emission source (and therefore possibly on facility property), we viewed aerial images of the facility to determine whether the block centroid was likely located on facility property. Likewise, we examined aerial images of all large census blocks within one kilometer of any emission source. If the block centroid did not represent the residential locations within that block, we relocated it to better represent them and/or we added receptors for residences nearer to the facility than the centroid. For these source categories, we added several receptors for census blocks where the centroid location was not representative of the residential locations. Appendix 7 of the risk assessment documents cited above provides additional information on these changes for each source category. Thus, despite the commenter's assertions, the EPA's approach to identifying the most exposed individual is reasonable.
4.9 Comment: One commenter (0684-0044) contended that the EPA is legally required to assess the health risks to the "individual most exposed" to these sources' emissions. 42 U.S.C. § 7412(f)(2). The commenter stated that the EPA must account for the increased susceptibility of children and developing fetuses to HAP emissions from this source category in the risk assessment. The commenter is concerned that the EPA's failure to include an adequate evaluation of increased early life susceptibility to HAP emissions systematically underestimates risk from the surface coating source categories. The commenter stated that the EPA's failure to account for vulnerability and variability based on the current science, particularly the science addressing early-life and socioeconomic factors in the risk related to exposure, has led EPA to underestimate the health risks that these sources cause to the most-exposed individuals. The commenter referred to the National Academy of Sciences (NAS) report and other new scientific and policy developments, stating that it directs the EPA to better account for vulnerability and variability. The commenter noted that the science is clear that "children are not `little adults'" when it comes to toxic chemicals, stating that they are 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.
The commenter (0684-0044) contended that the 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. The commenter stated that 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 draft risk assessments for this proposal. The commenter opined that EPA's demographic analysis acknowledges that disparities exist and shows the need for EPA to evaluate the impact of disproportionate exposure and health risks for certain demographic groups in the context of the risk assessment.
The commenter (0684-0044) argued that the EPA must, consistent with the Office of Environmental Health Hazard Assessment (OEHHA) Cancer Guidelines,[,] apply age-dependent adjustment factors for all carcinogens, not just known mutagens, to account for increased early life susceptibility and pre-natal adjustment factors for all carcinogens of at least a factor of 10X (similar to the 10X Age Specific Factor applied to the prenatal life stage by California EPA scientists), to account for pre-natal susceptibility and exposures. The commenter (0684-0044) noted that NAS has recognized this as a "missing" default in EPA's approach that it should address. The commenter quoted NAS: "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 (MOA) .... Special attention should be given to hormonally active compounds and genotoxic chemicals that do not meet the threshold of evidence requirements." The commenter (0684-0044) also argued that for chronic non-cancer risk, the EPA should apply an additional default or uncertainty factor (UF) to account for early-life exposure (i.e., a children's default safety factor such as those created by California EPA scientists) of at least 10 (for non-cancer chronic & acute impacts), where specific information on children's vulnerability is unavailable (consistent with NAS recommendations, the science developed and considered by OEHHA, and the 10X factor enacted by Congress in the Food Quality Protection Act). The commenter opined that most of the EPA's IRIS toxicity threshold values (RfCs and RfDs) used for chronic non-cancer risk assessment do not incorporate the latest science on increased susceptibility of children. The commenter noted that the EPA, in its risk assessment, has recognized that HAP, including nickel,  are emitted, and the commenter stated that the EPA needs to account for early exposure and the greater risk to and susceptibility of children to such compounds.
The commenter (0684-0044) contended that, under §7412(f)(2), it would be both unlawful for EPA to ignore the health risks that it knows that the HAPs emitted by these source categories can cause and it would be arbitrary and capricious for the EPA to avoid applying the best available science here. The commenter continued that it also would be unacceptable and unjust for the EPA to ignore the current scientific and regulatory tools available for communities affected by toxic air pollution from the current source categories and many others. The commenter argued that, if the EPA wishes to act on its stated commitment to environmental justice, it should finally start to use the science available now to address these impacts and risks, while also working to continue to update its risk assessment approaches.
The commenter (0684-0044) attached the health impact and risk documents cited in these comments as part of an accompanying Appendix, unless the documents were available to the EPA for other rulemakings or in the EPA Office of Science Advisor docket on the Request for Information on Cumulative Risk Assessment, EPA-HQ-ORD-2013-0292. The commenter stated that these comments incorporate all of the previously submitted scientific documents on these issues by reference.
4.9 Response: We disagree with the commenter's claim that the risk assessment for this source category does not consider the groups that may be most at-risk (e.g., children and developing fetuses). See the response to Comment 4.8 above for a discussion of EPA's approach to identifying the most exposed individual. In addition, when the EPA derives exposure RFCs and unit risk estimates for HAP, it also considers the most sensitive populations identified in the available literature, and importantly, these are the values used in our risk assessments. The EPA has an approach for selecting appropriate health benchmark values and, in general, this approach places greater weight on the EPA-derived health benchmarks than those from other agencies. Additionally, the approach of favoring the EPA benchmarks (when they exist) has been endorsed by the SAB and ensures the use of values most consistent with well-established and scientifically based EPA science policy. The EPA is continuing to evaluate the most appropriate use for the OEHHA's child-specific RfDs. We note that there are currently no such values for HAP inhalation; therefore, their current utility would be limited to persistent and bioaccumulative HAP (PB-HAP), which may be associated with non-negligible ingestion exposures. The evaluation of the appropriateness of these values in the context of the RTR program and EPA science policy is necessary prior to using these child-specific RfDs.
With respect to exposure, we use a health-protective assumption of a 70-year exposure duration, in which populations are conservatively presumed to be exposed to airborne concentrations at their residence continuously, 24 hours per day for a full lifetime, including childhood.
With respect to cancer, the EPA uses the age-dependent adjustment factor approach referred to by the commenter but limits the application of age-dependent adjustment factors to carcinogenic pollutants that are known to act via mutagenic MOA. In contrast, the OEHHA approach is to apply them across the board for all carcinogens, regardless of MOA. In lieu of chemical-specific data on which age or life-stage specific risk estimates or potencies can be determined, default age-dependent adjustment factors can be applied when assessing cancer risk for early-life exposures to chemicals which cause cancer through a mutagenic MOA. With regard to other carcinogenic pollutants for which early-life susceptibility data are lacking, it is the Agency's long-standing science policy position that use of a linear low-dose extrapolation approach (without further adjustment) provides adequate public health conservatism in the absence of chemical-specific data indicating differential early-life susceptibility or when the MOA is not mutagenicity.  The basis for this methodology is provided in the 2005 Supplemental Guidance.
The EPA also disagrees with the commenter that a children's default safety factor of ten or more should be added to EPA's reference values. In response to the comment on adding a tenfold factor to the EPA non-cancer reference value derivation, which the commenter claims would be consistent with the tenfold factor added for pesticide residue and other sources of exposure for infants and children in the Food Quality Protection Act (FQPA) (1996)[,], the EPA notes that it has evaluated its methods for considering children's risk in the development of reference values. The EPA (i.e., the Science Policy Council and Risk Assessment Forum) established the RfD/RfC Technical Panel to develop a strategy for implementing the FQPA and examining the issues relative to protecting children's health and application of the tenfold safety factor. One of the outcomes of the Technical Panel's efforts was an in-depth review of a number of issues related to the RfD/RfC process (EPA 2002). The most critical aspect in the derivation of a reference value pertaining to the FQPA has to do with variation between individual humans and is accounted for by a default UF when no chemical-specific data are available. The EPA reviewed the default UF for inter-human variability and found the EPA's default value of ten to be adequate for all susceptible populations, including children and infants. The EPA also recommended the use of chemical-specific data in preference to default UFs when available (EPA, 1994, 2011), and is developing Agency guidance to facilitate consistency in the development and use of data-derived extrapolation factors for RfCs and RfDs (EPA, 2011).  Additionally, the EPA also applies a database UF that is intended to account for the potential for deriving an under-protective RfD/RfC as a result of an incomplete characterization of the chemical's toxicity. In addition to the identification of toxicity information that is lacking, review of existing data may also suggest that a lower reference value might result if additional data were available.
In conclusion, the estimated risks must be considered in the context of the full set of assumptions used for this risk assessment. Our unit risk estimates for HAP are considered a plausible upper-bound estimate with an appropriate age-dependent adjustment factor; actual potency is likely to be lower and some of which could be as low as zero. Our chronic noncancer reference values have been derived considering the potential susceptibility of different subgroups, with specific consideration of children. In addition, an extra 10X UF is not needed in the RfC/RfD methodology because the currently available factors are considered sufficient to account for uncertainties in the database from which the reference values are derived. After consideration of these and other factors, we continue to find that the NESHAPs for these source categories provide an ample margin of safety (consistent with the Benzene NESHAP framework).
4.10 Comment: Commenter (0684-0044) stated that the risk assessment must account for each HAP emitted from the source categories and objected that in this risk assessment the EPA excluded altogether the effects of both nickel and lead.  The commenter requested that the EPA update the risk assessment using the CalEPA REL for nickel and to include emissions of lead.
The commenter (0684-0044) charged that the EPA risk assessment is unlawful because it treats the additional risk from nickel as zero, even though the EPA knows that nickel poses health risks. The commenter pointed out the California OEHHA has established an REL for nickel, and it is arbitrary for the EPA to not use it.
The commenter (0684-Sierrra) objected that the EPA's handling of lead is not acceptable under section 112(f). The commenter pointed out that the EPA excluded lead from the risk assessment because the EPA estimated that ambient concentrations of lead would be below the National Ambient Air Quality Standard (NAAQS) for lead; and the EPA, therefore, concluded that there was a "low potential for multipathway risk."  The commenter concluded that the EPA approach to lead is unlawful because meeting the lead NAAQS does not ensure an ample margin of safety to protect the public from the hazardous effects of lead. The commenter stated that lead is a well-known toxic heavy metal with diverse and severe health impacts of neurological, hematological, and immune effects on children, and hematological, cardiovascular, and renal effects on adults. The commenter also pointed out that children are particularly sensitive to the effects of lead, and that no safe blood lead level in children has been identified. The commenter concluded that excluding lead from the risk assessment underestimates the overall public health risks posed by these source categories.
The commenter (0684-0044) stated that EPA has a policy (as articulated in the Metal Coil residual risk assessment report for this action) of prioritizing certain scientific authorities for dose-response information according, in part, to "level of peer review received," and to use "the best available science with respect to dose-response information."  The commenter cited that, according to the EPA policy, the order of priority is: (1) EPA IRIS values which have all gone through independent, external peer-review; (2) ATSDR values, which follow an approach similar to EPA's IRIS program; and (3) CalEPA values for which "[t]he process for developing these assessments is similar to that used by the EPA to develop IRIS values and incorporates significant external scientific peer review."  The commenter stated that by refusing to use the ATSDR or CalEPA values for dose-response and failing to assess the inhalation and multipathway effects of lead, the EPA is not using the best available science and is underestimating public health risks from the combined effect of lead, nickel, and other HAP.
4.10 Response: This comment takes issue with the general manner in which the agency conducts part of its risk analysis without explaining how the commenter's concerns identify specific flaws for the source category at issue. Absent such a connection or a showing that a particular risk associated with nickel and lead emissions from the Metal Coil source category exists, it is unclear how the commenter would change the proposed action.  In any case, as explained further below, we maintain that our approach to analyzing the small amounts of nickel and lead emissions in the risk review for the Metal Coil source category is reasonable and we are not revising that approach in response to the comment. This comment does not apply to the Metal Can source category since those emissions did not include nickel or lead.
Nickel - In the RTR program, the EPA assesses acute risk using toxicity values derived from one-hour exposures. Based on an in-depth examination of the available acute value for nickel [California EPA's acute (1-hour) REL], we have concluded that this value is not appropriate to use to support the EPA's risk and technology reviews. This conclusion takes into account a number of factors, including: the effect on which the acute REL is based, aspects of the methodology used in its derivation, and how this assessment stands in comparison to the ATSDR toxicological assessment (which considered the broader nickel health effects database).
The broad nickel noncancer health effects database strongly suggests that the respiratory tract is the primary target of nickel toxicity following inhalation exposure. The available database on acute noncancer respiratory effects is limited and was considered unsuitable for quantitative analysis of nickel toxicity by both California EPA and ATSDR. The California EPA's acute (1-hour) REL is based on an alternative endpoint, immunotoxicity in mice, specifically depressed antibody response measured in an antibody plaque assay.
In addition, the current California acute (1-hour) REL for nickel includes the application of methods that are different from those described in EPA guidelines. Specifically, the (1-hour) REL applies uncertainty factors that depart from the defaults in EPA guidelines and does not apply an inhalation dosimetric adjustment factor.
Further, the ATSDR's intermediate MRL (relevant to nickel exposures for a time frame between 14 and 364 days), was established at the same concentration as the California EPA (1- hour) REL, indicating that exposure to this concentration "is likely to be without appreciable risk of adverse noncancer effects" (MRL definition) for up to 364 days.
We have high confidence in the nickel ATSDR intermediate MRL. Our analysis of the broad toxicity database for nickel indicates that this value is based on the most biologically relevant endpoint. That is, the intermediate MRL is based on a scientifically sound study of acute respiratory toxicity. Furthermore, this value is supported by a robust subchronic nickel toxicity database and was derived following guidelines that are consistent with EPA guidelines.  Finally, there are no AEGL-1/ERPG-1 or AEGL-2/ERPG-2 values available for nickel. Thus, for all the above-mentioned reasons, we did not include nickel in our acute analysis for this source category or in future assessments unless and until an appropriate value becomes available.
Lead  -  The NAAQS for lead was used as a health-based standard in this review. It was not simply adopted mechanically, but rather is justified under the independent decision framework in CAA section 112(f)(2). We note that the NAAQS for lead was set to protect, with an adequate margin of safety, the health of the most susceptible children and other potentially at-risk populations against an array of adverse health effects, most notably including neurological effects, particularly neurobehavioral and neurocognitive effects (which are the effects to which children are most sensitive) (73 FR at 67007). We further note that in developing the NAAQS for lead, air-related multipathway effects were already taken into account. That is, as noted at 73 FR at 66971 "As was true in the setting of the current standard, multimedia distribution of and multipathway exposure to Pb that has been emitted into the ambient air play a key role in the Agency's consideration of the Pb NAAQS." More discussion on the use of the lead NAAQS in RTRs is below.
While recognizing that lead has been demonstrated to exert "a broad array of deleterious effects on multiple organ systems," the lead NAAQS targets the effects associated with relatively lower exposures and associated blood lead levels, specifically nervous system effects in children including cognitive and neurobehavioral effects (73 FR 66976). The 2008 decision on the lead NAAQS was informed by an evidence-based framework for neurocognitive effects in young children. In applying the evidence-based framework, we focused on a subpopulation of U.S. children, those living near air sources and more likely to be exposed at the level of the standard; to the same effect see 73 FR 67000/3--"The framework in effect focuses on the sensitive subpopulation that is the group of children living near sources and more likely to be exposed at the level of the standard. The evidence-based framework estimates a mean air-related IQ loss for this subpopulation of children; it does not estimate a mean for all U.S. children"; 73 FR 67005/1--"the air-related IQ loss framework provides estimates for the mean air-related IQ loss of a subset of the population of U.S. children, and there are uncertainties associated with those estimates. It provides estimates for that subset of children likely to be exposed to the level of the standard, which is generally expected to be the subpopulation of children living near sources who are likely to be most highly exposed." In addition, in reviewing and sustaining the lead primary NAAQS, we note that the D.C. Circuit specifically noted that the rule was targeted to protect children living near lead sources: "EPA explained that the scientific evidence showing the impact of lead exposure in young children in the United States led it `to give greater prominence to children as the sensitive subpopulation in this review' and to focus its revision of the lead NAAQS on the `sensitive subpopulation that is the group of children living near [lead emission] sources and more likely to be exposed at the level of the standard.' Given the scientific evidence on which it relied, the EPA's decision to base the revised lead NAAQS on protecting the subset of children likely to be exposed to airborne lead at the level of the standard was not arbitrary or capricious."  Coalition of Battery Recyclers, 604 F. 3d at 618.
As noted in the risk assessment document, there is no RfD or other comparable chronic health benchmark value for lead compounds. In 1988, the EPA's IRIS program reviewed the health effects data regarding lead and its inorganic compounds and determined that it would be inappropriate to develop an RfD for these compounds, stating,
      "A great deal of information on the health effects of lead has been obtained through decades of medical observation and scientific research. This information has been assessed in the development of air and water quality criteria by the Agency's Office of Health and Environmental Assessment (OHEA) in support of regulatory decision-making by the Office of Air Quality Planning and Standards (OAQPS) and by the Office of Drinking Water (ODW). By comparison to most other environmental toxicants, the degree of uncertainty about the health effects of lead is quite low. It appears that some of these effects, particularly changes in the levels of certain blood enzymes and in aspects of children's neurobehavioral development may occur at blood lead levels so low that a threshold has yet to be determined. The Agency's RfD Work Group discussed inorganic lead (and lead compounds) at two meetings (07/08/1985 and 07/22/1985) and considered it inappropriate to develop an RfD for inorganic lead."
The EPA's IRIS assessment for lead and compounds (inorganic) (CASRN 7439-92-1) can be found here:  https://cfpub.epa.gov/ncea/iris2/chemicalLanding.cfm?&substance_nmbr=277.
4.11 Comment: One commenter (0684-0044) asserted that the EPA must recognize that chronic (non-cancer) risk-causing pollutants have no safe level of exposure, noting that the NAS recommends that cancer and chronic non-cancer risk assessment use the same approach in order to address the fact that even very low levels of non-carcinogen exposures can pose health risks. The commenter noted that the use of reference doses (RfDs) for dose-response risk assessments of chronic non-cancer health effects may significantly underestimate risk, because the risk assessments focus on the RfD or RfC, and the EPA defines these values as a dose "likely to be without an appreciable risk of deleterious effects" over a lifetime of exposure.
The commenter (0684-0044) identified what they see as the problems with traditional toxicology as the basis for risk assessments, including the presumption that health effects are related to dose, and that a dose can be found for virtually all chemicals where no effect is found. The commenter claimed that the greatest public health threat of chemicals is for fetal exposure, meaning that the dose may be less important than the timing, and furthermore that for some toxic chemicals, the clinical effect can actually increase as the chemical concentration decreases, meaning that there is no safe level of exposure. For example, the commenter noted that a 2009 statement by the Endocrine Society stated that "[e]ven infinitesimally low levels of exposure, indeed, any level of exposure at all, may cause endocrine or reproductive abnormalities, particularly if exposure occurs during a critical developmental window. Surprisingly, low doses may even exert more potent effects than higher doses." The commenter also identified a report published in The New England Journal of Medicine, regarding the toxicity of volatilized compounds from oil made these important statements illustrating the risk from small exposures to toxic agents:
      "Mutagenic effects theoretically can result from a single molecular DNA alteration. Regulatory prudence has led to the use of `one-hit models' for mutagenic end points, particularly cancer, in which every molecule of a carcinogen is presumed to pose a risk."; and "Pregnant women should particularly avoid dermal contact with oil and should avoid areas with visible oil contamination or odors."
The commenter (0684-0044) also noted that a recent panel of twelve national endocrine disruptor specialists recently stated that "[for] every chemical that we looked at that we could find a low-dose cutoff, if it had been studied at low doses it had an effect at low doses."  The commenter further noted that a recent joint public statement by the American College of Obstetricians and Gynecologists and the American Society for Reproductive Medicine addressed the extraordinary vulnerability of in utero development.
4.11 Response:  Chronic noncancer dose-response values used in the RTR program, including those derived by the EPA and similar authoritative agencies (e.g., Agency for Toxic Substances and Disease Registry (ATSDR) and CalEPA), represent chronic exposure levels that are intended to be health protective. Those values are derived using an approach that is intended to not underestimate risk in the face of uncertainty and variability. When there are gaps in the available information, uncertainty factors (UFs) are applied to derive reference values that are protective against appreciable risk of deleterious effects. Uncertainty factors are commonly default values  (e.g., factors of 10 or 3) used in the absence of compound-specific data; where data are available, data-derived extrapolation factors may also be developed using compound-specific information. When data are limited, more assumptions are needed, and more default factors are used. Thus, there may be a greater tendency to overestimate risk -- in the sense that further study might support development of reference values that are higher (i.e., less potent) because fewer default assumptions are needed. For some pollutants, however, there is a slight possibility that risks could be underestimated. Where data indicate a potential vulnerability of a specific life stage, the EPA includes this information in its derivation of cancer and noncancer dose-response values. In some instances, data are not available for a robust characterization of risk during a specific life stage and, in that case, potential susceptibilities are accounted for by applying the appropriate uncertainty factors.
The EPA agrees with the NAS that the recommendations on harmonization of cancer and non-cancer approaches are important issues in risk assessment and the EPA incorporates NAS recommendations as feasible. The NAS has agreed with the EPA, specifically on the derivation methodology of RfCs and RfDs, that the available scientific information does not always allow for assessment derivation issues to be fully considered, and it has reviewed and supported the approaches currently used in the derivation of the RfCs and RfDs. The NAS has also recognized that many of the recommended changes for the IRIS Program will need to be incorporated over a number of years and further recommend continuation of the development of assessments as the recommendations are implemented (i.e., the process should not be halted until all recommendations can be enacted). As such, improvements will be made over time and existing assessments will need to be used in the interim. Further, the EPA has a legal obligation to proceed with regulatory action based on the best available data and tools. Because we use the best available data and tools, apply conservative assumptions, and take into account uncertainties, we tend to err on the side of overestimating risk in determining whether risk is acceptable. The commenter stated that there are problems associated with traditional toxicology presumption that health effects are related to dose; however, the commenter does not provide any information to consider an alternative paradigm to risk assessment that would not include an analysis of dose-response relationships in the risk assessment process.
The commenter provided a reference to support the statement that there is no safe level of exposure and that, for fetal exposure, the dose may be less important than the timing, and furthermore that for some toxic chemicals, the clinical effect can actually increase as the chemical concentration decreases. The review article on hormones and endocrine-disrupting chemicals focuses on a broad category of chemicals that appear to act at low concentrations. We disagree with the interpretation of the commenter on the referenced review. First, the authors of the review article do not conclude that there is no safe level of exposure for chemicals in general, not even for endocrine disruptors. We disagree with the comment that clinical effect increases as dose of the chemical decreases; rather, the authors of the review conclude that the effect of low doses of this group of chemicals cannot be predicted by effects observed at high doses, and they encourage investigators to make changes in chemical testing approaches to identify potential endocrine disruptors. We conclude that none of the information or conclusions in the review article conflicts with the EPA's determinations in this regulatory action.
We agree with the comment that the regulatory community, including the EPA, should use conservative approaches to evaluate cancer risks, especially when considering cancer risks to early life stages. When chemical-specific data are available on which age or life-stage specific risk estimates or potencies can be determined, default age-dependent adjustment factors can be applied when assessing cancer risk for early-life exposures to chemicals which cause cancer through a mutagenic mode of action. With regard to other carcinogenic pollutants for which early-life susceptibility data are lacking, it is the Agency's long-standing science policy position that use of the linear low-dose extrapolation approach (without further adjustment) provides adequate public health conservatism in the absence of chemical-specific data indicating differential early-life susceptibility or when the mode of action is not mutagenicity. The basis for this methodology is provided in the 2005 Supplemental Guidance.
4.12 Comment: One commenter (0684-0044) argued that the EPA underestimated acute health risks for several reasons. The commenter argued that the EPA incorrectly estimated peak emissions using a peak-to-mean ratio of only 1.1. The commenter argued that, among other things, the ratio of mean to peak emissions will vary depending on whether the emissions are controlled by a pollution control device (where failure could lead to emissions as high as 100 times the controlled level) and whether the processes involved are continuous or batch processes. The commenter reasoned that the EPA also assumed 24/7/365 operation, which leads to lower emissions per hour than are likely to occur. The commenter further maintained that risks are underestimated because the EPA ignored the increased risk of nickel by not using the REL and because the EPA ignored the effect of emissions during non-routine, malfunction, and upset-based spikes.
4.12 Response: The EPA disagrees with the commenter that the development of the acute risk multipliers was not adequately documented because the development of the emissions multipliers was documented in Appendix 1 of the risk assessment report for each source category. The EPA's analyses support the conclusion that the multipliers chosen are reasonable for these source categories. Each of these source categories perform surface coating generally using continuous processes. In these two source categories (Metal Cans and Metal Coil), add-on controls are used at facilities that do not use compliant materials in the coating processes. In the event of a control device malfunction, these coating processes can be quickly stopped (e.g., the can coating lines can be stopped; the coil coating rollers can be retracted from the coil substrate and no additional coating applied) and excess emissions would be minimized. This is different from other industries in which it may take several hours to completely shut down a process and cease air emissions. Thus, for both source categories, the multiplier does not need to be nearly as high as it would be for other industries. The EPA considered variations in emissions during routine operations and assumed operations occurred 8,760 hours per year, based upon information provided by the industry representatives. For these reasons, the EPA concludes that the data support the factors used in the acute health risk analyses, and, therefore, those factors are appropriate for each of the source categories.
4.13 Comment: According to one commenter (0684-0044), the EPA's multipathway risk assessment falls short because the EPA did not complete this analysis for all persistent or bioaccumulative pollutants, it did not use "allowable" emissions for this assessment, and it did not assess all exposure routes  -  particularly for children. The commenter states that it is also problematic that the EPA failed to use the information it found from the multipathway analysis in its overall risk analysis, because it did not add the multipathway risk to the inhalation risk.
The commenter (0684-0044) stated that the multipathway risk screening assessment was restricted to only those contaminants identified in the 2004 Risk Assessment Guidance as being both persistent and bioaccumulative in the environment (i.e., PB-HAPs). They state that this list of fourteen PB-HAPs is incomplete as it ignores other HAPs which present a multipathway risk.
The commenter (0684-0044) described why they believe the 2004 guidance is deficient and concluded that the EPA must perform a full multipathway risk assessment for all HAP (including naphthalene, antimony, and nickel) emitted by these source categories. The commenter noted that OEHHA has recommended a multipathway assessment based on scientific research and developed a method to conduct this assessment, and the EPA should apply this science in its risk assessments.
The commenter (0684-0044) argued that the EPA must assess multipathway risk based on "allowable" emissions, not just the so-called "actual" emissions, which are likely underestimated. The commenter argued that the EPA assessed the "allowable" emissions number for inhalation and has given no reasonable basis not to do the same for multipathway risk. The commenter argued that doing so would change the calculations of health risks the EPA is relying on for its § 7412(f)(2) proposed determination.
The commenter (0684-0044) argued that the EPA has recognized the need to assess risk based on the greatest allowable amounts of inhalation-risk pollutants (beyond what a facility may report as "actual" emissions), but has not done the same to assess risk for persistent and bioaccumulative emissions by failing to assess the potential for greater amounts of such PB-HAP emissions. The commenter argued that intermittent or short spikes of PB-HAPs can represent a significant health risk because the contaminants stay in the environment and small amounts can accumulate into larger amounts over time. For this reason, according to the commenter, the EPA's analysis likely underestimates the health risks from multipathway routes of exposure, and the EPA must assess the combined impact of multiple pollutants.
4.13 Response: The EPA does not agree that the approach to conducting multipathway risk assessments is flawed or that EPA must expand the pollutants subject to such assessments at this time. The HAP listed by the commenter (naphthalene, antimony and, nickel) have not been identified by the EPA as persistent bioaccumulative HAP. We disagree that the risk assessment was inadequate because it did not include multipathway risk assessments for these HAP. In the Air Toxics Assessment Library, we developed the current PB-HAP list considering all of the available information on persistence and bioaccumulation (see http://www.epa.gov/ttn/fera/risk_atra_main.html). This list included HAP identified as PB-HAP by other EPA Program Offices (e.g., the Great Waters Program), as well as information from the PBT profiler (see http://www.pbtprofiler.net/). This list was peer reviewed by the SAB and found to be acceptable and, therefore, we consider it to be reasonable for use in the RTR program. Based on these sources and the limited available information on the persistence and bioaccumulation of other HAP, we do not think that the potential for multipathway risk from the other HAP cited by the commenter warrants a multipathway assessment.
For these source categories, the difference between actual and allowable emissions is small (1.1 times actual emissions), so the use of allowable emissions would not have significantly changed the results of the assessment, or the conclusion on risk acceptability. However, we have not used allowable emissions in RTR multipathway assessments for several reasons. Typically, estimates of allowable emissions are more uncertain than estimates of actual emissions. That uncertainty, combined with the conservative nature of multipathway screens, could lead to results that are too uncertain and conservative to be of practical use.  Of course, in cases where we have good estimates of allowable emissions and we do a site-specific multipathway assessment, the results are less uncertain and less conservative. However, we conclude that the use of actual emissions is more defensible because of the conservatism that exists in the site-specific assessment.  The fisher and gardener in the site-specific assessment are hypothetical since we  are uncertain if fishing or gardening activities are conducted near a facility. Also, we use high-end estimates of ingestion in the site-specific assessment, which makes it conservative.
4.14 Comment: One commenter (0684-0044) noted that the EPA recognizes that it must assess the combined impact of cancer risks from different carcinogens to create a combined cancer risk from inhalation and that it must assess the combined chronic non-cancer risk for different chemicals that affect the same target organ. The commenter argued that the EPA should apply the same scientific principles to recognize that it also must combine and look at the whole picture of all other kinds of risk from multiple pollutants.
The commenter (0684-0044) stated that the EPA fails to reach a combined cancer risk value that includes inhalation and multipathway risks of cancer, and that this is unlawful and arbitrary. The commenter argued the EPA must 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 commenter (0684-0044) stated that, to look overall at a person's exposure, the 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 a cumulative burden metric, makes the EPA's overall risk assessment incomplete. The commenter stated that the EPA must assess the total and synergistic chronic non-cancer risk for different pollutants that may work in different ways than EPA has acknowledged here.
The commenter (0684-0044) added that the EPA should apply these same principles to create a mechanism for assessing the total acute risk to chemical mixtures, such as the target organ-specific hazard index (TOSHI) for chronic risk, that aggregates the acute impacts on the same organ systems for all pollutants. EPA's decision to assess acute risks solely chemical by chemical, when it knows the collection of HAPs are being released together, is unlawful and arbitrary. The result is an underestimation of the full acute health risks to which the most-exposed individual and nearby community members are exposed.
4.14 Response: We have combined risk assessment results to the extent that it is appropriate to do so and disagree with the comment that we failed to consider or account for cumulative risk. The EPA conducted an assessment of the cumulative cancer risks from all emitted carcinogens and the cumulative noncancer hazard indices from all emitted non-carcinogens that are HAPs affecting the same target organ system for both the source category emissions and the facility-wide emissions. To address the effect of mixtures of carcinogens, the individual cancer risks for the source category were aggregated for all carcinogens. In assessing the noncancer hazard from chronic exposures for pollutants that have similar modes of action or that affect the same target organ, we aggregated the HQs to provide a TOSHI. We do not use a TOSHI approach for our acute analyses nor do we combine the results of our inhalation and multipathway assessments. We further modeled whole-facility risks for both chronic cancer and non-cancer impacts to understand the risk contribution of the co-located sources within each of the three source categories.
For each source category, the EPA conducted an assessment of the cumulative cancer risks from all emitted carcinogens and the cumulative noncancer hazard indices from all emitted non-carcinogens that are HAPs affecting the same target organ system for both the source category emissions and the facility-wide emissions.
The EPA modeled whole-facility risks for both chronic cancer and non-cancer impacts to understand the risk contribution of the sources within each source category. The individual cancer risks for the source categories were aggregated for all carcinogens. In assessing noncancer hazard from chronic exposures for pollutants that have similar modes of action or (where this information is absent) that affect the same target organ, we aggregated the HQs. This process creates, for each target organ, a TOSHI, defined as the sum of HQs for individual HAP that affect the same organ or organ system. All TOSHI calculations presented here were based exclusively on effects occurring at the "critical dose" (i.e., the lowest dose that produces adverse health effects).
As described in the risk assessment document available in the docket, we do not sum results of the acute noncancer inhalation assessment to create a combined acute risk number that would represent the total acute risk for all pollutants that act in a similar way on the same organ system or systems (similar to the chronic TOSHI). The worst-case acute screen is a conservative scenario. That is, the acute screening scenario assumes worst-case meteorology, peak emissions for all emission points occurring concurrently and an individual being located at the site of maximum concentration for an hour. Thus, as noted in the residual risk assessment document for each source category, because of the conservative nature of the acute inhalation screening and the variable nature of emissions and potential exposures, acute impacts were screened on an individual pollutant basis, not using the TOSHI approach.
4.15 Comment: The 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. The EPA should be integrating its assessments and performing a "comprehensive risk assessment" as the NAS has emphasized.  The commenter cited NAS as saying, "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." The commenter recommended that after first assessing the total cancer, chronic non-cancer, and acute risks, for both inhalation and multipathway exposure, the EPA should follow the approach by CALEPA to create a metric to assess the total bundle of risks. Otherwise, the commenter concluded that the EPA is unable to make an ample margin of safety determination based on the full measure of health risk.
4.15 Response: We disagree that this type of comprehensive assessment, which the commenter believes is mandated by the CAA, is required. The CAA requires that the EPA regulate the risks from the source category, and incorporates the approach outlined in the Benzene NESHAP, which is based on risk acceptability and ample margin of safety decisions. The EPA's current approach is consistent with the approach in the Benzene NESHAP, and that action does not require the analysis suggested by the comment.
4.16 Comment: One commenter (0684-0044) argued that the EPA's risk assessment must account for the cumulative impact from exposure to multiple source categories' air emissions. The commenter stated that this is in keeping with a SAB May 2010 recommendation to incorporate cumulative risk into the residual risk analysis.  The commenter stated that EPA should combine current baseline emissions, exposures, and health impacts in addition to those of the specific source category, as well as evaluate background exposures and vulnerability factors. The commenter explained that this consideration is necessary to address the disproportional impact on minority and low-income communities that is caused because multiple toxic sources tend to be located in such communities. The commenter recommended that the EPA draw on the OEHHA cumulative assessment approach for its risk assessment or incorporate an explicit default or UF to adjust the degree to which each source category is contributing to the total risk experienced by the most-exposed individuals. For a source category in an area with up to 10 other HAP-emitting facilities, the commenter stated that this default or UF should equal at least 10.
4.16 Response: We disagree with the claim that additional quantitative assessment of risks from sources outside the source category is required for this rulemaking. Section 112(f) requires the EPA to perform a review of whether there is risk remaining from emissions from a source category after promulgation of the technology-based MACT standards for that source category. To this end, the EPA conducts a comprehensive assessment of the risks associated with exposure to the HAP emitted by the source category and supplements that with additional information that is available about other possible concurrent and relevant risks. The incorporation of additional background concentrations from the environment in our risk assessments (including those from mobile sources and other industrial and area sources) would be technically challenging, and such analyses are neither mandated nor barred from our overall risk analysis approach. In developing the decision framework in the Benzene NESHAP currently used for making residual risk decisions, the EPA rejected approaches that would have mandated consideration of background levels of pollution in assessing the acceptability of risk, concluding that comparison of acceptable risk should not be associated with levels in polluted urban air (54 FR 38044, 38061, September 14, 1989). Background levels (including natural background) are not barred from the EPA's ample margin of safety analysis, and the EPA may consider them, as appropriate and as available, along with other factors, such as cost and technical feasibility, in the second step of its section 112(f) analysis. This assessment excludes background contributions because the available data are of insufficient quality upon which to base a meaningful analysis. Further, as explained at proposal, our approach here is also consistent with the approach we took regarding this issue in the HON RTR (71 FR 76603, December 21, 2006), which the court upheld in the face of claims that the EPA had not adequately considered background concentrations. (NRDC v. EPA, 529 F.3d 1077 (D.C. Cir. 2008)).
4.17 Comment: Commenter (0684-0044) asserted that for the risk assessment the EPA must consider the potential for hexavalent chromium emissions from the use of high-temperature metalworking operations at can and coil coating facilities. The commenter pointed out that the South Coast Air Quality Management District conducted ambient air monitoring and found hexavalent chromium emissions in 2016-17. The commenter declared that the EPA must consider the health risks from hexavalent chromium and revise the standards as necessary to protect public health.
4.17 Response: The reference cited by the commenter, Emissions of Toxic Air Contaminants from Chromium Alloy Melting Operations, is only relevant to the melting of chromium alloys such as alloy steel, stainless steel, and super alloys. It is not relevant to the operations in either the surface coating of metal cans or metal coil source categories. High-temperature metal working operations are not found at metal can surface coating facilities. Some high-temperature metal working operation are collocated with coil coating operations, but they are not part of the metal coil surface coating source category.
 5.0	Technology Reviews
5.1 Comment: One commenter (0684-0046) supported the EPA's conclusion that there have been no technology developments in the surface coating of metal cans that make rule revisions necessary in the NESHAP for the Surface Coating of Metal Cans. One commenter (0685-0048) supported the EPA's conclusion that there have been no technology developments in the surface coating of metal coil that make rule revisions necessary in the NESHAP for the Surface Coating of Metal Coil.
5.1 Response: The EPA acknowledges the two commenters' support for the technology review conclusions for surface coating of metal cans and surface coating of metal coil.
5. 2 Comment: One commenter alleged that the EPA has not met the legal obligation under CAA section 112(d)(6) to review and revise emission standards "as necessary" to account for "developments in practices, processes, and control technologies." The commenter objected that the EPA proposed no revisions to the emission limits and claimed the EPA provided no legally valid or rational explanation for its determination of a lack of "developments" for these two source categories. The commenter pointed out that the EPA identified several HAP control advancements, including alternative coatings, developments for similar source categories, and work practices and housekeeping measures for Metal Coil facilities, which would reduce emissions and are in use at a number of facilities, yet failed to determine that it was "necessary" to revise the standard. In addition, the commenter alleged that the EPA technology review analysis did not consider some relevant sources to determine "developments." As examples, the commenter stated that the EPA did not analyze any control methods or requirements from other national or state or local jurisdictions that might have proven more effective; did not appear to analyze the different methods or brands of emission controls implemented to see which was most effective, efficient, or reliable; and did not examine facility procedures or best practices, including records of malfunctions, to identify best practices to mitigate malfunctions.

5.2 Response: We disagree with the commenter that the EPA has failed to meet the Act's legal obligation to complete the technology reviews for the metal can and the metal coil coating source categories. The EPA concluded there were no HAP control advancements for these source categories as a result of the technology reviews. The technology reviews included review of coatings currently used by these source categories and any advancements in the coatings; review of HAP control requirements in NESHAP for similar coating source categories and application of those HAP controls to the metal cans and metal coil source categories; state and local HAP control requirements in title V operating permits and application of those HAP controls to the metal cans and metal coil source categories; and work practices and housekeeping measures currently used by these source categories and any advances that were applicable to these source categories.

As stated in the proposal preamble (84 FR 25935) for the metal coil coating source category, alternatives to solvent borne coatings have been in use by the coil coating industry since development of the 2002 Surface Coating of Metal Coil NESHAP but are not considered to be suitable for all end-product applications. The 2002 proposed NESHAP provided an alternative facility HAP emission limit of 0.24 pounds of HAP per gallon of solids applied which was established to provide a compliance option for facilities that chose to limit their coating line HAP emissions either through a combination of low-HAP coatings and add-on controls or through the use of waterborne, high solids, or other pollution prevention coatings. The EPA found no developments in alternative coating technologies during the technology review that would result in achievable emission rates that are substantially lower than those reflected in the current emission limits.

The commenter also asserted that the EPA did not consider developments in control methods for similar source categories and did not analyze the regulations set by state or local jurisdictions that might have proven more effective than the NESHAP requirements. We disagree with the commenter and refer the commenter to the technology review memos titled Technology Review for Surface Coating Operations in the Metal Can Category and Technology Review for Surface Coating Operations in the Metal Coil Category which summarizes the EPA's review of the title V operating permits for the five metal can facilities and for 39 metal coil facilities that are major sources and subject to these NESHAP. The title V operating permits incorporate all relevant local, state, or regional emission limitations, as well as federal limitations. In no case did the EPA find a facility subject to a HAP limit more stringent than the limits in the current NESHAP or a facility using a control technology that was not considered during development of the NESHAP and reflected in the current standards. The results of the technology reviews were documented in these memos in the respective docket for each proposed rule.

The technology basis for MACT for metal coil coating operations in the 2002 Surface Coating of Metal Coil NESHAP was emission capture and add on control with an overall control efficiency of 98 percent for new or reconstructed sources and existing sources. This overall control efficiency represents the use of PTE to achieve 100 percent capture of application station HAP emissions and a thermal oxidizer to achieve a destruction efficiency of 98 percent. No technology was identified during the technology review that could achieve a better overall control efficiency than the use of a PTE to capture HAP emissions from the coating application station and a thermal oxidizer to destroy HAP emissions from the coating application and the curing oven.

It would not be feasible, nor is it required under CAA section 112(d)(6), for the EPA to evaluate HAP control advancement by examining different brands of emission controls to see which was most effective, efficient, or reliable, as suggested by the commenter. Similarly, it would not be feasible to examine facility procedures or best practices, nor review records of malfunctions to identify best practices to mitigate malfunctions. That information is not currently available to the EPA. If the information was available, it would be difficult, if not impossible, to correlate that information with emissions performance and develop practical regulatory requirements. Instead, the current emission limits are based on actual performance of existing sources in the two categories determined to represent the MACT level of control for new and existing sources. The performance data used to develop the emission limits were collected during emission tests when the control devices were performing properly and the emission sources were at steady-state operating conditions. Data collected during periods of startup, shutdown, or malfunction were not used to establish the emission limits. After the initial compliance demonstration, facilities using add-on controls must comply with operating limits to ensure the add-on controls continue to be properly operated and maintained to achieve the same level of performance as during the performance test. Facilities experiencing deviations from the emission limits or the operating limits must report these deviations to the EPA, and the EPA will then determine on a case-by-case basis whether the deviation constitutes a violation. Because of the diversity of factors that could lead to a malfunction in these source categories, it would not be practical for the EPA to prescribe specific actions that must be taken to reduce the frequency of malfunctions or to minimize emissions in the event of a malfunction.

The commenter also asserted that the EPA identified work practices and housekeeping measures for Metal Coil facilities, which would reduce emissions and are in use at a number of facilities yet failed to determine that it was "necessary" to revise the standard. The commenter's assertion appears to be based on a statement in the preamble to the proposal where we note that the facility survey conducted as part of the development of the 2002 MACT standard for Surface Coating of Metal had revealed several types of work practices and housekeeping measures in use at that time. (84 FR at 25935). We also noted in the preamble, however, that we had identified no developments in work practices or procedures for the Surface Coating of Metal Coil source category. As the commenter has provided no additional information regarding possible developments and as the EPA has no information about developments in such work practices and housekeeping measures, we do not agree that it is necessary to revise the standard for this source category as a result of the technology review.
 6.0	Electronic Reporting Provisions
6.1 Comment: One commenter suggested that the EPA change the metal can compliance schedule language in proposed 40 CFR 63.3511(f) for submission of semiannual compliance reports to give facilities either 1 year (instead of 181 days) after the final rule is published to begin electronic reporting or 1 year after the 40 CFR part 63, subpart KKKK, semiannual compliance report template is available in Compliance and Emissions Data Reporting Interface (CEDRI), whichever is later. The commenter recommended revising 40 CFR 63.3511(f) to say that on and after the date 1 year (instead of 181 days) after the date of publication of final rule in the Federal Register, or once the reporting template has been available on the CEDRI Web site for 1 year, whichever date is later, the owner or operator is required to submit the semiannual compliance report via the CEDRI. The commenter noted that the proposed 181-day requirement for 40 CFR part 63, subpart KKKK, is not consistent with the 1-year requirement the EPA is proposing for 40 CFR 63.5181(c) in 40 CFR part 63, subpart SSSS for the Surface Coating of Metal Coil source category. The commenter also argued that 1 year would be justified because metal can coating facilities are not currently using CEDRI and would need to learn how to access and use CEDRI.

6.1 Response: The EPA agrees that both rules should be consistent and that the owners and operators should have 1 year after the date of publication of the final rule or 1 year after the reporting template has been on CEDRI, whichever is later, before they are required to submit semiannual compliance reports via CEDRI. This will provide users 1 year to become familiar with the template and electronic reporting system prior to being required to submit reports electronically. This will provide adequate time for facilities to adjust to electronic reporting, as well as assure that the forms will work properly, prior to the date that owners and operators must start submitting these reports electronically. The EPA encourages users to become familiar with the system well in advance of being required to use it. For previous rulemakings with reports required to be submitted electronically via CEDRI, prior to a compliance reporting deadline, the EPA has provided webinars to our various stakeholders on the access and reporting of the given report in CEDRI. The EPA is planning to provide this same service to the industry trade association and facilities subject to the subpart KKKK and subpart SSSS electronic reporting requirements, if requested to do so. The EPA plans to publish the final template on CEDRI about the same time the final rule is signed and published. Although facilities will have up to 1 year after the final template is on CEDRI to begin using the template and submitting reports via CEDRI, facilities may begin submitting reports via CEDRI as soon as the final template is available.
6.2 Comment: One commenter (0684-0046) supported the EPA's proposal to include electronic reporting submission date extensions when there are Central Data Exchange (CDX) or CEDRI outages or force majeure events outside the control of the owner or operator. However, the commenter argued that the EPA should also add a provision to allow "first-time" users to apply for extensions in cases where they are having difficulty uploading data.
6.2 Response: The EPA is allowing a one-year period after the reporting template is available in CEDRI before facilities are required to begin submitting semiannual compliance reports via CEDRI. The EPA has included this period to allow facilities to become familiar with the reporting template and the process for submitting reports via CEDRI and no additional extensions for first-time users should be needed. Once the template is available in CEDRI users will have the ability to use it to start creating reports. The template will also be available on the CEDRI website https://www.epa.gov/electronic-reporting-air-emissions/cedri. As such, all users will have at least one year to become familiar with the template and electronic reporting system prior to being required to submit reports electronically. This should provide adequate time for facilities to adjust to electronic reporting, as well as assure that the forms will work properly, prior to the date that owners and operators must start submitting these reports electronically. The EPA encourages users to become familiar with the system well in advance of being required to use it. For previous rulemakings with reports required to be submitted electronically via CEDRI, prior to a compliance reporting deadline, the EPA has provided webinars to our various stakeholders on the access and reporting of the given report in CEDRI. The EPA is planning to provide this same service to the industry trade association and facilities subject to the subpart KKKK electronic reporting requirements, if requested to do so.

6.3 Comment: One commenter (0684-0046) requested that the EPA notify facilities directly, rather than relying on affected sources having to monitor the CEDRI website to determine when a final electronic reporting template is posted.
6.3 Response: The EPA notes the comment and will consider automated avenues of communication such as listserve or an email blast for CEDRI users if the reporting template is not finalized concurrent with the publication of the final rule. The EPA plans to have the final electronic reporting templates available in CEDRI concurrent with publication of the final rules in the Federal Register. The EPA has met this schedule for the previous surface coating rules that were also amended to require electronic reporting via CEDRI. Therefore, facilities should check CEDRI (or the CEDRI drupal webpage https://www.epa.gov/electronic-reporting-air-emissions/cedri) for the final reporting template when the final rule notice is published in the Federal Register.
6.4 Comment: One commenter (0684-0046) expressed concern that the new federal electronic requirement will result in an additional burden on affected facilities that may need to prepare separate reports for federal and state/local air agencies. The commenter argued that state and local air agency staff will only have access to the federal reports if they are registered in CEDRI and choose to use it. The commenter also argued that there is no reason to believe that states will accept printed copies of the electronic report submittals as meeting the NESHAP requirement for submitting semiannual reports to state permitting authorities. Therefore, the commenter argued that electronic submissions through CEDRI should be mandatory for affected sources only in states that will accept those electronic submissions as meeting the requirement to submit semiannual compliance reports to the state, and optional in all others.

The commenter (0684-0046) also argued that the compliance burden for electronic reporting and performance testing is underestimated. The commenter argued that facilities will no longer be able to send EPA a copy of the report they send to the state as a way to meet the federal reporting requirements. Therefore, the commenter argued, even after learning to use CEDRI in the first year after the rule is final, facilities will have additional costs in subsequent years submitting separate electronic reports to CEDRI and paper reports to state agencies. The commenter argued that the costs in subsequent years should reflect the hours to create and upload the reporting data to CEDRI.
6.4 Response: The EPA disagrees that the electronic reporting requirements will result in additional burden for industry and is requiring the use of CEDRI as proposed. The commenter has not presented evidence of, and the EPA is also not aware of any states not accepting copies of electronic reports. Once entered in CEDRI, a copy of the semiannual compliance report can be saved as a PDF file, formatted to fit on 8-1/2 by 11-inch pages, and either printed and mailed to a state agency or delivered electronically as an attachment. The narrative and upload fields within the CEDRI forms can be used to provide information to satisfy extra reporting requirements that state and local air agencies may impose. These printed reports provide a cost-effective option for satisfying a state or local air agency's request for a printed report. Therefore, the EPA disagrees that this will create an additional burden for facilities located in states that are not accepting semiannual compliance reports via CEDRI.

A number of air agencies have already indicated their intention of adopting the EPA's electronic reporting program. The EPA believes that more air agencies will eventually adopt the system, as the system benefits air agencies by streamlining review of data, facilitating large scale data analysis, providing accessibility to reports anywhere reviewers have access to the Internet, and providing cost savings through a reduction in storage costs. Furthermore, the EPA regional offices can access reports submitted to their delegated air agency via CEDRI, eliminating the submittal of courtesy copies.

Based on the analysis performed for the Electronic Reporting and Recordkeeping Requirements for the New Source Performance Standards (ERRRNSPS) (80 FR 15100, March 20, 2015), electronic reporting results in an overall cost savings to industry when annualized over a 20-year period. The cost savings is achieved through means such as standardization of data, embedded quality assurance checks, automatic calculation routines, and reduced data entry through the ability to reuse data in files instead of starting from scratch with each report. As outlined in the ERRRNSPS, there are many benefits to electronic reporting. These benefits span all users of the data  -  EPA, state and local regulators, the regulated entities, and the public. The memo included in the dockets for the proposed amendments to the NESHAP for Surface Coating of Metal Cans and the NESHAP for the Surface Coating of Metal Coil (Electronic Reporting Requirements for New Source Performance Standards (NSPS) and National Emission Standards for Hazardous Air Pollutants (NESHAP) Rules, August 8, 2018), present a number of reasons why the electronic reporting required by this rule will provide benefit going forward and that most of the benefits outlined were longer-term benefits (e.g., eliminating "paper-based, manual processes, thereby saving time and resources, simplifying data entry, eliminating redundancies, minimizing data reporting errors and providing data quickly and accurately to affected facilities, air agencies, EPA, and the public.").
EPA has worked and will continue to work with air agencies on the development of our electronic reporting tools. EPA's electronic reporting program is part of the E-Enterprise for the Environment initiative, a collaborative effort between EPA and air agencies through Environmental Council of States (ECOS). Additionally, as documented in the Compliance and Emissions Data Reporting Interface Integrated Project Team Guidance and Recommendations Document (September 26, 2013, EPA Docket ID No. EPA-HQ-OAR-2009-0174-0059), EPA convened an Integrated Project Team (IPT) to gather ideas from air agencies on the data flow process within CEDRI, including data submission, data resubmission, and data access requirements of the CEDRI data flow.
EPA routinely discusses electronic reporting with air agencies and EPA regional offices. Quarterly calls are conducted with EPA regional offices to provide information that will be helpful in their outreach efforts to the air agencies in their regions. EPA has performed demonstrations of the CEDRI reporting program and the ERT for EPA regional offices and their associated air agencies, as well as for air agency groups like the Mid-Atlantic Regional Air Management Association (MARAMA).
Additionally, through the E-Enterprise's Combined Air Emissions Reporting (CAER) project, the EPA is working with air agencies to streamline multiple emissions reporting processes. Currently, air emissions information is collected by the EPA and air agencies through numerous separate regulations, in a variety of formats, according to different reporting schedules, and using multiple routes of data transfer. The CAER project seeks to reduce the cost to industry and government for providing and managing important environmental data. More information on CAER can be found at: https://www.epa.gov/e-enterprise/e-enterprise-combined-air-emissions-reporting-caer.
According to the 2013 Policy Statement on E-Reporting in EPA Regulations, ". . . E-Reporting is not simply a regulated entity e-mailing an electronic copy of a document (e.g., a PDF file) to the government. Rather, E-Reporting is defined as a system in which an electronic tool guides the regulated entity through the reporting process often with built-in compliance assistance and data quality checks." EPA believes that the electronic submittal of the reports addressed in this rulemaking increases the usefulness of the data contained in those reports, is in keeping with current trends in data availability, further assists in the protection of public health and the environment and will ultimately result in less burden on the regulated community. Additionally, in 2011, in response to Executive Order 13563, EPA developed a plan to periodically review its regulations to determine if they should be modified, streamlined, expanded, or repealed in an effort to make regulations more effective and less burdensome. The plan includes replacing outdated paper reporting with electronic reporting. In keeping with this plan and the Digital Government Strategy, in 2013 EPA issued an agency-wide policy specifying that new regulations will require reports to be electronic to the maximum extent possible. By rquiring electronic submission of reports in this rule, EPA is taking steps to implement this policy. Therefore, the requirement to report these data electronically in the spreadsheet template are being retained in the final rule.
6.5 Comment: One commenter (0684-0046) stated they will need an interactive discussion with the EPA (e.g., by conference call or webinar) to answer questions about how to use CEDRI and about the draft electronic reporting template before they can effectively comment on whether the template is appropriate and workable for metal can surface coating facilities subject to Subpart KKKK. The commenter further asked that the EPA not finalize the reporting template until after the proposed rule is finalized.
6.5 Response: The EPA agrees that interactive discussions via conference calls or a webinar with the industry trade organization and members would be appropriate to review the electronic reporting process using CEDRI and to collaborate on improvements to the draft electronic reporting template. The EPA has arranged interactive discussions with both the metal can and metal coil industry trade organizations and members in an attempt to finalize the electronic reporting templates concurrent with the final rule promulgation. If that is the case facilities will have 1 year after the final rule is published to submit notifications and semiannual compliance reports using the electronic reporting template in CEDRI. If the reporting templates are not finalized concurrent with the final rule promulgation, the EPA will continue to work with the industry trade organizations and members to finalize the templates and will make the final templates available on the CEDRI website. Facilities would then be required to submit notifications and semiannual compliance reports using the electronic reporting template in CEDRI one year after the reporting template has been available on the CEDRI website.
6.6 Comment: One commenter (0684-0046) argued that numerous places in the reporting template require selecting an option from a dropdown list, but the proposed e-reporting template does not allow reviewers to see or comment on those dropdown options. For example, a "Company Record Number" first appears on the Compliance Options tab and then shows up on all subsequent tabs. The commenter noted that it requires selecting an entry from a dropdown list but the entries in the list are not provided for review. The commenter noted that the template contains numerous other examples of where dropdown lists occur, but they cannot be seen to review.
6.6 Response: The dropdown lists are a quality assurance feature to reduce repetitive data entry and eliminate erroneous entries in subsequent tabs. The company record number is entered on the company information tab by the template user (i.e., the reporting facility) or is automatically generated when user provides the company name, and then it becomes part of the record number drop down list and appears on subsequent tabs. The first two data rows in each tab do not contain any dropdown lists because they are examples that are locked and cannot be used for data entry. The first blank row in each tab after the two example rows contain the dropdown lists and the options in the lists can be reviewed in the first blank row.
The EPA plans to revise the instructions in the final template to clarify these features. These features will be  covered in conference calls and web conferences that will be held to discuss using CEDRI and the templates, as discussed in the response to Comment 6.5.
6.7 Comment: One commenter (0684-0046) requested that the EPA ensure that the template will allow for reporting in a form consistent with the compliance options available under 40 CFR 63 subpart KKKK. The commenter noted that 40 CFR 63.3490 allows affected sources to use any of the four compliance options on any individual coating operation or multiple coating operations within a subcategory or coating type segment as a group. The commenter also noted that affected sources may use different compliance options for different coating operations or at different times on the same coating operation. The commenter argued that, for example, it is not clear that the reporting template would allow a facility to demonstrate compliance by combining the sheet coating operations on multiple coating lines to calculate a monthly emission rate number.
6.7 Response: The EPA has reviewed and revised the reporting template and the instructions to clarify how facilities should use the template when using different compliance options at different times, and when combining operations at different times to demonstrate compliance. The template allows a facility to create multiple entries for coating operations and this allows a facility to create a separate record for each compliance scenario the facility used during the compliance period, and the beginning and ending dates for each scenario. The EPA has also revised the subpart KKKK template to accommodate facilities that choose to calculate and comply with an Overall Subcategory Emission Limit (OSEL) according to 40 CFR 63.3531(i).
6.8 Comment: One commenter (0684-0044) supported the electronic reporting requirement to assure and account for compliance but argued that the EPA may not create any CEDRI outage or unlawful "force majeure event" exceptions to reporting, or any other requirements, as it proposes to do. The commenter argued that the EPA has proposed a provision amending subparts KKKK and SSSS to allow extensions for electronic reporting deadlines that should not be finalized, as these are unlawful and arbitrary for the reasons discussed below. The first part of the proposed provision allows an extension of the deadline to submit an electronic report due to "a claim of EPA system outage" of CEDRI within a 5-business day time period of the deadline. The second part of the provision allows an extension if a force majeure event occurs or is still occurring or if there are lingering effects of the event in the 5 business days prior to a submission deadline. In neither circumstance does the EPA set a new firm deadline to submit the required report, nor does it set a firm deadline to request an extension of the reporting deadline. The proposed provision merely states that "[t]he decision to accept the claim . . . and allow an extension to the reporting deadline is solely within the discretion of the Administrator, and reporting should occur as soon as possible," according to the commenter.
The commenter (0684-0044) argued that if an event occurs that delays reporting, the EPA and/or a court may address the implications of that event in an administrative or judicial enforcement proceeding, as part of the penalty assessment tests applicable under 42 U.S.C. § 7413(d) (EPA) and (e) (court). The commenter argued that the EPA has no lawful basis or authority to add any such exemption into the Clean Air Act, as the D.C. Circuit has previously explained in rejecting a similar "affirmative defense" to civil penalties for malfunctions. NRDC v. EPA, 749 F.3d 1055 (D.C. Cir. 2014).
The commenter (0684-0044) argued that the EPA's proposed options for extensions to electronic reporting deadlines are unlawful and arbitrary because they would create a broad and vague mechanism that an owner or operator could use to evade binding emission standards, by evading the binding compliance reporting deadlines set to assure compliance with those standards. The commenter argued that the Act sets binding compliance deadlines for air toxics emission standards that EPA may not lawfully evade or extend. [See, e.g., 42 U.S.C. § 7412(i)(3)(A), (B) (requiring compliance dates for section 112(d) standards "which shall provide for compliance as expeditiously as practicable, but in no event later than 3 years after the effective date of such standard," unless a 1-year extension is granted if "necessary for the installation of controls"); id. § 7412(f)(4) (requiring compliance by all new sources with a section 112(f) emission standard on its effective date, and by all existing sources by 90 days after the effective date, and allowing extensions for existing sources of only up to two years after the effective date of a standard if "necessary for the installation of controls" and as long as "steps will be taken during the period of the waiver to assure that the health of persons will be protected from imminent endangerment").] The commenter asserted that the EPA's proposal to extend compliance dates for reporting is an unlawful extension of emission standards, as those compliance dates are an essential part of ensuring that the emission standard is in force and compliance is assured. According to the commenter, the proposed extension provisions would allow sources not to meet for a period of time, or possibly ever, the regulations' firm and enforceable reporting deadlines to submit information, which are required to assure compliance with the emission standards by the deadlines set by law, as the Act requires.
The commenter (0684-0044) argued that the new proposed provisions would remove the deadline for a particular reporting requirement without creating a new firm deadline. Thus, the language "as soon as possible" removes a requirement ensuring the enforceability of the requirements and makes it likely that reporting will be significantly delayed, at best. At worst, it may lead a facility to drag its feet in submitting reports for an extended period, or ever, within a time when corrective action could and should be taken to prevent harmful and unlawful emission exceedances. Because the EPA's proposal contains no new deadline, it is not an extension provision, it is an exemption. An exemption from reporting requirements is equivalent to an unlawful exemption from the standards. As long as a facility need not report, it need not be in compliance. The extension provisions are also arbitrary and capricious.
The commenter (0684-0044) argued that, as an additional problem, there is simply no authority for the EPA to allow any type of "force majeure event" exception or extension under the Clean Air Act. As the commenters quoted from their 2016 petroleum refinery comments (EPA-HQ-OAR-2010-0682-0889), this is a law enacted to protect public health and welfare by reducing pollution and all of the harm it causes, including cancer and other serious health impacts from hazardous air pollution. The commenters argued that the concept of "force majeure" comes from contract law, but the Clean Air Act is not a contract, and it is instead a binding legal requirement that facilities have no choice but to meet if they seek to emit hazardous air pollution. The commenters argued that the EPA should not import the concept of "force majeure" into any part of the Clean Air Act, and its attempt to do so is just another variation of the prior malfunction exemptions that are unlawful under the Act, as the D.C. Circuit has repeatedly held. The commenters argued there is no "force majeure" exception allowed for non-compliance with the Clean Air Act or its requirements, and EPA may not create such an exemption.
The commenter (0684-0044) argued that in the event that EPA does create a "force majeure event" extension provision, it must, at least, ensure that the facility is required to prevent similar problems in the future, and report what steps it will take in the future to prevent the same problem from recurring. The commenter asserted that when there is such a problem, the need for prompt reporting is especially important so that the EPA can ensure that any actual emissions exceedances end and are corrected. Thus, the commenter argued, allowing an unreasonable extension or not setting any deadline is especially unlawful and problematic because of the greater need for prompt reporting in the event of the type of incident the EPA describes in order to protect public health and welfare.