1

BID II: Response to Comments

Risk and Technology Review for Wood Furniture Manufacturing and 

Shipbuilding and Ship Repair (Surface Coating) Operations

Comment No. Commenter Affiliation

37 J. Frye

38 John Gahm Kitchen Kompact

39 Bob Terhune Masco Cabinetry

40 Sheila Holman North Carolina Department of Environment and Natural 

Resources (NC DENR)

41 Melvin Keener Coalition for Responsible Waste Incineration

42 Vinson Hellwig and Robert Colby National Association of Clean Air Agencies (NACAA)

43 Bill Perdue American Home Furnishings Association

44 Traylor Champion Georgia-Pacific

45 Emma Cheuse and Jim Pew Earthjustice

46 Shannon Broome Air Permitting Forum

48 Anthony Wagner American Chemical Council – Glycol Ethers Panel

49 David Darling American Coatings Association (ACA)

50 Dick Titus Kitchen Cabinets Manufacturers Association

51 Laura Brust American Chemical Council – Formaldehyde Panel

52 Mathew Todd The Residual Risk Coalition

53 Thomas Hoerman AkzoNobel Coatings

54 Wayne S. Holt Environmental Technologies Panel - National 

Shipbuilding Research Program

55 Harvey Clewell and 

Mel Andersen

The Hamner Institutes for Health Sciences on behalf of 

American Chemistry Council
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I. GENERAL COMMENTS PERTAINING TO BOTH WOOD FURNITURE 

COATINGS AND SHIP BUILDING AND REPAIR COATINGS.........................................3

A. RISK ASSESSMENT..................................................................................................3

B. SSM PROVISIONS...................................................................................................31

C. ENVIRONMENTAL JUSTICE ...............................................................................50

II. WOOD FURNITURE ..................................................................................................52

A. RISK ASSESSMENT................................................................................................52

B. FORMALDEHYDE LIMIT .....................................................................................66

C. GLYCOL ETHERS ..................................................................................................71

D. SPRAY GUNS............................................................................................................73

E. SSM PROVISIONS...................................................................................................78

F. RULE TEXT CORRECTIONS................................................................................79

III. SHIPBUILDING............................................................................................................81

A. RISK ASSESSMENT .................................................................................................81

B. WELDING AND ABRASIVE BLASTING .............................................................84

C. ENVIRONMENTAL JUSTICE ...............................................................................95
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I. GENERAL COMMENTS PERTAINING TO BOTH WOOD FURNITURE 

COATINGS AND SHIP BUILDING AND REPAIR COATINGS

A. RISK ASSESSMENT

1. Comment: A few commenters (40, 42, and 45) agreed with EPA's use of California 

Reference Exposure Levels (RELs) and conducting refined analyses for acute exposures 

regarding risk results above threshold levels.

However, the three commenters disagreed with the use of emergency exposure limits like Acute 

Exposure Guideline Levels (AEGLs) or Emergency Response Planning Guidelines (ERPGs). 

The commenter asserted that the use of AEGLs and ERPGs are not appropriate because the 

target population is not the general public, but emergency response personnel.

Commenter 42 noted a December 2002 EPA document, A Review of the Reference Dose and 

Reference Concentration Processes:

EPA stated that the primary purpose of the AEGL program is to develop guidelines 

for once-in-a-lifetime short-term exposures to airborne concentrations of acutely toxic 

chemicals. They are not meant to evaluate the acute impacts from routine emissions 

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

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

uncertainty factors and cannot be relied upon to protect the public from the adverse 

effects of exposure to toxic air pollutants.

Commenter 45 cited a review by the Science Advisory Board (SAB):

SAB review of EPA‘s draft entitled, ―Risk and Technology Review (RTR) Risk 

Assessment Methodologies: For Review by the EPA‘s Science Advisory Board with 

Case Studies – MACT I Petroleum Refining Sources and Portland Cement 

Manufacturing,‖ EPASAB-10-007 at 6 (May 07, 2010)) (―SAB May 2010‖) The 

AEGL and ERPG numbers would be expected to underestimate risk over a longer 

time period. This is because exposure levels that may not cause acute effects after a 

short exposure can cause effects over longer time periods. Using values derived for 

use for acute exposures to represent chronic exposures is scientifically incorrect. 

Doing so is likely to discount or cloak the level of risk to the maximum exposed 

individual. These values are therefore not appropriate for use in the section 112(f)(2) 

residual risk analysis. They simply do not provide sufficient protection for health.

Several commenters stated that AEGL, ERPG, and Immediately Dangerous to Life and 

Health (IDLH) values should not be used in assessing the risk from acute exposures to 

ethylene oxide because these values were developed for accidental release planning and are 

not appropriate for assessing daily human exposure scenarios. One commenter stated that 

EPA‘s acute assessment discounted the use of the National Institute of Occupational Safety 

and Health (NIOSH) 10-minute ceiling value of 5 parts per million (ppm) (9 mg/m3), and 

noted that EPA‘s maximum acute exposure estimate for this source category (23 mg/m3) 

exceeds the NIOSH value. Two of the commenters stated that EPA‘s new acute reference 

concentration value for ethylene oxide should be used when it becomes available.
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Response: EPA uses AEGL and ERPG values (when available) in conjunction 

with REL values (again, when available) to fully characterize potential acute risks. 

We also examine a wider range of available acute health metrics which may include IDLH 

values to reduce data gaps and inconsistencies in acute reference values. Then, when 

interpreting the results, we are careful to note the definition of the benchmark being used and the 

health implications associated with any specific benchmark being exceeded. Historically, 

comparisons of the estimated maximum off-site one-hour exposure levels have not been 

typically made to OSHA occupational levels for the purpose of characterizing public health risks 

in RTR assessments. This is because occupational ceiling values are not generally considered 

protective for the general public because they are designed to protect the worker population 

(presumed healthy, working age adults) for short duration (<15 minute) increases in exposure. 

As a result, for most chemicals, the 15-minute occupational ceiling values are set at levels higher 

than a one-hour AEGL-1, making comparisons to them irrelevant unless the AEGL-1 or ERPG-1 

levels are exceeded. Such is not the case when comparing the available inhalation NIOSH acute 

occupational guideline ceiling value for formaldehyde. The worst-case maximum estimated 1-

hour exposure to formaldehyde exceeds the 15-minute (NIOSH REL-ceiling value of 0.12 

mg/m3;) by a factor of 3. In any event, we have concluded that these source categories do

not present acute health risks that warrant further regulation based upon the worstcase nature of the screening approach used.

2. Comment: Two commenters (42 and 45) were concerned that EPA used long-term 

concentrations affecting the most highly-exposed census block for each facility. According to 

commenter 42, this analysis ―dilutes the effect of sources‘ emissions by estimating the impact at 

the centroid of the census block instead of at the facility fence or the property line.‖ 

According to commenter 45, the center of a census block is almost always further away from the 

facility than the fenceline. The commenter noted that census blocks vary greatly in size but EPA 

provided no evidence of reviewing census block sizes or configurations to consider how 

pollutant concentrations might vary within these blocks. The commenter was concerned that the 

area-weighted centers of census blocks may be significantly underestimating exposure in some 

cases. The commenter recommended moving receptor points closer to the facility to assess 

chronic exposure in those instances where local residents live nearer to a facility than the 

geographic centroid of the census block.

Commenter 42 continued by stating that over time homes and businesses could locate closer to 

any facility. The commenter doubted that population distribution is homogenous over a census 

block resulting in inaccuracy in the predicted impacts. 

Response: As we have noted in the development of previous RTRs, such as the SOCMI 

HON RTR (71 FR 76603, December 21, 2006), EPA contends that, 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. Further, EPA asserts that it is appropriate 

to use census block information on where people actually reside, rather than points on a fenceline, to locate the estimation of exposures and risks to individuals living near such facilities. 
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Census blocks are the finest resolution available as part of the nationwide population data (as 

developed by the US Census Bureau); each is typically comprised of approximately 40 people or 

about 10 households. In 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 experiences the 

maximum individual risk. 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 blocks 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 census blocks are larger, although there is still 

no bias on average. 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 fencelines do not typically 

represent locations where chronic exposures are likely, and 3) there is no bias introduced into the 

estimate of the MIR by using census block centroid locations.

3. Comment: Commenters 42 and 45 agreed with EPA's approach in considering the acute 

risks for HAPs at the ―point of highest off-site exposure for each facility (i.e., not just the census 

block centroids)‖ for the non-cancer health effects.

Response: In contrast to the development of ambient concentrations for evaluating longterm exposures, which was performed only for occupied census blocks, worst-case acute (onehour) concentrations were estimated both at the census block centroids and at points nearer the 

facility that represent locations where people may be present for short periods, but generally no 

nearer than 100 meters from the center of the facility (note that for large facilities, this 100-meter 

ring could still contain locations inside the facility property). For facilities with HQ values 

exceeding 1, a refined evaluation of GIS maps was conducted to verify that the location 

associated with the exceedance was actually off-site.

4. Comment: Commenters 42 and 45 urged EPA to respond to the SAB‘s recommendation to 

present the risk assessment results ―in the broader context of aggregate and cumulative risks, 

including background concentrations and contributions from other sources in the area.‖

On the other hand, commenter 46 stated that even if legally permissible, consideration of 

background risks would result in a program that sets caps on total exposures for HAPs in 

geographic areas. The commenter stated:

Consideration of background exposures to HAPs could result in policies that 

effectively prevent any HAP emissions from a source regulated under section 112 in 

a given area if EPA determines that the emissions, when coupled with background 

exposure levels, could result in a Hazard Quotient or total cancer risk level that 

exceeds an acceptable risk. Implementation of this policy would incorrectly and 

unfairly place a disproportionate burden on individual sources up for review. If 

ambient concentrations from EPA‘s NATA program are used in determining 

acceptability or ample margin of safety for individual source categories (as suggested 

by EPA as one possibility), these sources would not only have to compensate for 
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other high emitting stationary sources of HAPs, they may also have to compensate for 

mobile source emissions that may be unacceptably high due to traffic congestion. 

Moreover, the Clean Air Act expressly excludes mobile source emissions from the 

definition of ―stationary source.‖ 42 U.S.C. §§7411(a)(3). The inequities would be 

further compounded by the fact that EPA bases decisions for source categories on the 

individual source posing the highest potential risks. Other sources in the source 

category may not be located in areas of high background concentrations, but would 

likely be forced to install the same control technologies. EPA‘s decision to consider 

background concentrations would recast the program from a source-category driven 

program to a program that focuses on total loadings and total exposures. The Clean 

Air Act, however, clearly distinguishes between source category programs and 

programs that focus on total loadings or exposures, such as the National Ambient Air 

Quality Standards (―NAAQS‖) under section 108 or the Prevention of Significant 

Deterioration (―PSD‖) program under Part C of Title I of the Clean Air Act. 

Response: An assessment of the cumulative cancer risks from emitted carcinogens and the 

cumulative noncancer hazard indices from all emitted non-carcinogens affecting the same target 

organ system for both the source category emissions and the facility-wide emissions was 

conducted by EPA. This is excluding background contributions. While the incorporation of 

additional background concentrations from the environment in our risk assessments (including 

those from mobile sources and other industrial and area sources) could be technically 

challenging, they are neither mandated nor barred from our analysis. In developing the decision 

framework in the Benzene NESHAP1currently used for making residual risk decisions, 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 of certain HAPs can be relatively high, perhaps even above a level that might 

be considered  ̳ ̳safe.‘‘ Background levels (including natural background) are not barred from 

EPA‘s ample margin of safety (AMOS) analysis, but 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 112(f) analysis. In this analysis background levels were not considered because it is 

technically infeasible. This is because for these source categories technical limitations in the data 

set would be insufficient to create a reliable analysis.

5. Comment: Commenter 42 urged EPA to reach the lowest, most health-protective level of 

risk by assessing the population at risk for cancer by measuring the number of people at greater 

than one-in-one million risk, greater than ten-in-one-million risk, and greater than 100-in-onemillion risk. The commenter supported that approach for decisions concerning acceptability and 

ample margin of safety determinations under Section 112(f) of the Clean Air Act. 

Commenter 45 asked that EPA, before finalizing, strengthen the residual risk standard for 

formaldehyde emissions from wood furniture manufacturing to decrease the cancer risk to be no 

greater than 1-in-1 million. The commenter asked that EPA address what standard is needed ―to 

 

1 National Emission Standards for Hazardous Air Pollutants: Benzene Emissions from Maleic Anhydride Plants, 

Ethylbenzene/Styrene Plants, Benzene Storage Vessels, Benzene Equipment Leaks, and Coke By-Product Recovery 

Plants (54 FR 38044, September 14, 1989) (Benzene NESHAP).
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provide maximum feasible protection against risks to health‖ by ―protecting the greatest number 

of persons possible‖ to a lifetime risk level no greater than 1-in-1 million, 75 Fed. Reg. at 80,223 

(quoting Benzene NESHAP).

Response: As stated in the Benzene NESHAP, in determining the need for residual risk 

standards in the risk acceptability determination, we strive to limit to no higher than 

approximately 1-in-10 thousand (100-in-1 million) the estimated risk that a person living near a 

plant would have if he or she were exposed to the maximum pollutant concentrations for 70 

years and, in the ample margin of safety determination, to protect the greatest number of persons 

possible to an individual lifetime risk level of no higher than approximately 1-in-1 million. 

However, in determining whether to require additional standards, these levels are not considered 

rigid lines, and we weigh the cancer risk values with a series of other health measures and 

factors, including estimates of uncertainty, in both the risk acceptability and the ample margin of 

safety determinations. If we determine that the risk is unacceptable, we must impose additional 

requirements to reduce emissions without consideration of cost. However, as part of our 

determination of whether standards protect public health with an ample margin of safety, we do 

not look solely at whether technology is ―feasible,‖ (as urged by the commenter) but also 

consider cost, as statutorily required. We are also required to consider cost as part of technology 

review under section 112(d)(6), which we are required to perform periodically.

6. Comment: Commenters 42 and 45 urged EPA to take additional steps to address facilitywide risks.

Alternatively, commenter 46 noted that consideration of facility-wide or background risks is 

contrary to the express language of the statute, is bad policy, and should not apply to EPA‘s 

residual risk review under Section 112(f). 

EPA‘s proposal to conduct facility-wide residual risk determinations and to consider 

potential background exposures is contrary to the express language of section 112. 

The plain meaning of the statute in section 112(f) requires that each source category 

be evaluated and regulated separately. Reviewing the emissions on a facility basis, 

rather than a source-by-source basis, may over estimate the risks associated with the 

sources covered by the applicable MACT standard being reviewed and, on the other 

hand, may not properly account for the emissions from the other source categories to 

present an appropriate residual risk review under section 112(f). EPA cannot exceed 

its authority by imposing a more stringent requirement to address potential (and 

uncertain) risks not caused by the sources and not contemplated by Congress.

Commenter 52 further stated that the ―total facility‖ approach to conducting risk assessment 

exceeds EPA‘s authority under § 112(f). 

EPA explains in the Proposal that, ―To put the source category risks in context, we 

also examined the risks from the entire ―facility,‖ where the facility includes all 

HAP-emitting operations within a contiguous area and under common control. 

Because the CAA requires residual risk determinations to be conducted on a 

category by category basis, EPA does not have authority to consider the combined 
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emissions from entire facilities when making a § 112(f) risk assessment for a given 

source category. 

Commenter 46 noted that consideration of facility-wide risks would have adverse policy 

consequences:

The practical effect could be to constrain the ample margin of safety level for 

individual source categories well beyond the level provided for in the 1989 Benzene 

Rule decision framework for individual MACT source categories. For facilities that 

may have multiple MACTs, the consequences of allowing the facility-wide ample 

margin of safety determinations could significantly reduce the allowable emission 

levels, with unacceptable and unpredictable implications for the operation of the 

facility. Second, implementation of facility-wide ample margin of safety, even at the 

stage of addressing the last relevant MACT source category, is likely to be infeasible 

for many facilities. Trying to reconcile aggregated risk from different HAPs from 

disparate sources which may be geographically far apart (e.g., process unit fugitives 

vs. a distant tank or stack) would be difficult to accomplish and is unlikely to 

illuminate better emission reduction opportunities than residual risk analyses for 

individual MACT source categories.

Commenter 46 stated the 1989 Benzene Rule itself, codified in the CAA, does not call for 

facility-wide risk determinations or regulation. Instead, the rule focuses on emission sources 

included in the benzene NESHAP categories. 

Even where the 1989 Benzene Rule considers more than a single emission source, it 

only aggregates emissions from sources within the same category or subcategory, 

describing these emissions as emissions from two or more sources in the same source 

category that are located so closely together that they may result in greater risks to 

individuals because they are potentially exposed to both sources at the same time. 54 

Fed. Reg. at 38,045. This very limited concept of co-located sources in the same 

category is wholly different from what EPA appears to describe as a ―facility-wide‖ 

residual risk determination in the Proposed Rule.

According to commenter 52, Section 112(f)(2)(A) unambiguously requires EPA, within 8 years 

after adopting a MACT standard for a given source category or subcategory to promulgate 

standards for such category or subcategory if promulgation of such standards is required in order 

to provide an ample margin of safety to protect public health. 

It is not reasonable to construe these provisions as authorizing EPA to consider 

emissions from entire facilities in conducting risk assessments and potentially 

revising the underlying rule for the simple reason that the Congress clearly envisioned 

that full implementation of the MACT program would take longer than 8 years. 

Consequently, it would be impossible for EPA to fulfill its unambiguous obligation 

for § 112(f) standards to protect public health with an ample margin of safety in cases 

where facilities contain sources in a category where the 8 year deadline for 

conducting the § 112(f) risk review precedes the adoption of MACT standards for 

other sources at the facilities. One example is the boiler source category. The 

provisions at §112(f)(2)(A) unambiguously requires the risk assessment to be focused 

exclusively on ―emissions from a source in the category or subcategory.‖ For this 
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reason alone, EPA does not have authority to consider emissions from any sources 

other than those in the source category or subcategory under review at that time.

Commenter 46 responded to EPA‘s request for comments concerning whether NATA might be 

used to measure background exposures for purposes of decision making under section 112(f). 75 

Fed. Reg. at 80,225. 

Given the plain meaning of the statute and the text of the 1989 Benzene Rule, section 

112 does not allow the consideration of background concentrations in determining 

acceptable risk or ample margin of safety. However, even if it were legally 

permissible to consider background HAP concentrations, NATA remains a too blunt 

and inexact instrument to be used for this regulatory purpose. As EPA states on its 

NATA website, NATA should only be used for determining regulatory priorities, not 

for making individual regulatory decisions: ―These [NATA] assessments are based on 

assumptions and methods that limit the range of questions that can be answered 

reliably. The results cannot be used to identify exposures and risks for specific 

individuals, or even to identify exposures and risks in small geographic regions such 

as a specific census block, i.e., hotspots.‖ (http://www.epa.gov/ttn/atw/natamain/)

Commenter 46 endorsed EPA‘s decision to adhere to the 1987 Vinyl Chloride decision (NRDC, 

Inc. v. EPA, 824 F.2d 1146 (D.C. Cir. 1987)), and the decision framework established in the 

1989 Benzene Rule (54 Fed. Reg. 38,044 (Sept. 14, 1989)), codified by statute under section 

112(f)(2)(B). 

The 1989 Benzene Rule states that maximum individual risks as high as one-in-ten 

thousand can be presumptively considered ―safe‖ or ―acceptable.‖ Maximum individual 

risks greater than one-in-ten thousand may also be considered safe based on a careful 

review of the specific health factors and uncertainties involved.

EPA appears to have followed an acceptable approach in the Proposed Rule. For 

Shipbuilding and Ship Repair, EPA found an acceptable risk. EPA then ―weighed all health 

risk measures and information considered in the risk acceptability determination, along 

with the costs an economic impacts of emissions controls, technological feasibility, 

uncertainties, and other relevant factors.‖ As an example, EPA looked at requiring 

enclosure of some or all coating operations and requiring emissions to be routed to a 

control device, but found this proposal ―is not practicable or technically feasible in many 

cases, would not be cost-effective, and we are not aware of any facility using an enclosure 

of this size [(i.e., entire ship or large portion of a ship)].‖ Id. EPA followed a similar 

approach for Wood Furniture Manufacturing, finding the risks from the source category 

were acceptable. Id. at 80,245. EPA then appropriately considered costs and feasibility to 

determine whether additional controls are warranted for an ample margin of safety.Id. at 

80,245-80,246. Thus, EPA appropriately considered whether technical or economic 

feasibility would exclude this technology option from being required as part of the ample 

margin of safety decision under section 112(f).

EPA again confirmed that bright-line, inflexible decision points for acceptable risks or an 

ample margin of safety for future residual risk standards should be avoided: ―As explained 

more fully in our Residual Risk Report to Congress, EPA does not define  ̳rigid line[s] of 
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acceptability,‘ but considers rather broad objectives to be weighed with a series of other 

health measures and factors (EPA–453/R–99–001, p. ES–11).‖ The Forum continues to 

support this approach to allow for flexibility. Nonetheless, while EPA may consider other 

health measures and factors in applying the benzene decision framework, these factors 

were intended primarily to address uncertainties in the risk estimates, and do not serve as 

an open ended invitation for the Agency to include factors that would dramatically alter the 

fundamental elements of the program and the decision framework in the 1989 Benzene 

Rule. The 1989 Benzene Rule and Congress‘s codification of it (and therefore the statutory 

terms) should not be rendered meaningless. Thus, so long as EPA finds the risks acceptable 

and protective with an ample margin of safety under the 1989 Benzene Rule framework, 

EPA can properly determine that no further regulation is necessary under section 112(f).

Commenter 52 suggested that EPA provide justification or a rational basis for considering 

demographics in deciding whether an ample margin of safety has been achieved. The commenter 

noted that this is a departure from the risk assessment methods established in prior § 112(f) 

residual risk determinations. 

Section 112(f)(2)(A) expressly instructs EPA to impose additional emissions controls 

if needed to provide an ample margin of safety ―to protect public health. The term 

―public health‖ is not defined in § 112 or in EPA‘s Part 63 regulations. The term 

―public health‖ cannot reasonably be interpreted to include consideration of 

environmental justice in the § 112(f) context. Therefore, EPA‘s proposal to consider 

demographic analyses in conducting risk reviews under § 112(f) is not a proper 

exercise of Agency authority. In the context of EPA‘s national ambient air quality 

program, the Supreme Court has observed that public health means ―the health of the 

public.‖ The word ―public‖ should be construed expansively as describing the people 

as a whole, and not particular demographic segments. 

EPA‘s established approach to assessing potential impacts on public health under the 

NAAQS program is consistent with this meaning. EPA reasonably interprets the term 

―public health‖ to include consideration not only of potential impacts to the 

population as a whole, but also to sensitive subpopulations – recognizing that the 

objective is to protect the group rather than any particular individual in the group.

Commenter 46 agreed with commenter 52 that sensitive subpopulations should be identified 

according to their particular health-based sensitivities (e.g., asthmatics) rather than demographic 

classifications unrelated to particular health-based sensitivities (e.g., population without a high 

school diploma):

EPA cannot presume that sensitive subpopulations exist without supporting health 

evidence linking the pollutant being emitted to greater health effects in the 

subpopulation. Nor can EPA presume that race, income, age or education is a 

surrogate for a sensitive subpopulation. Because EPA has failed to provide this 

evidence in this rulemaking, EPA cannot consider race, education or income in 

decisions regarding acceptable risk or ample margin of safety for the source 

categories addressed in this proposal. In any event, EPA found ―no demographic 

group is exposed to an unacceptable level of risk.‖ 75 Fed. Reg. at 80,252.
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In analyzing potential demographic risks, EPA focused on populations within 50 km 

of any facility estimated to have exposures to HAP which result in cancer risks 

greater than one-in-a-million or non-cancer HI of 1 or greater. 75 Fed. Reg. at 80,231. 

Commenter 46 agrees, to the extent EPA conducts an EJ analysis, that EPA should 

focus on risks of potential concern, EPA has recognized that a 5 km radius generally 

encompasses more than 90 percent of the population that are estimated, using 

conservative assumptions, to have risks greater than one in a million. 75 Fed. Reg. at 

65,080. The expansion from 5km to 50km may reduce the accuracy of the resulting 

information, including the potential link between source category emissions and the 

population at risk. This is especially true given the conservative assumptions EPA 

uses in developing individual and population risk estimates, and the need to provide 

health evidence showing that the population category in question is more sensitive 

than the population at large to health effects that could be caused by emissions from 

the source category.

Response: We examined facility-wide risk to provide additional context to the source 

category risks. In May 2010, the SAB advised us ―* * * RTR assessments will be most useful to 

decision makers and communities if results are presented in the broader context of aggregate and 

cumulative risks, including background concentrations and contributions from other sources in 

the area.‖ The development of facility-wide risk estimates provides additional information about 

the potential cumulative risks in the vicinity of the RTR sources, as one means of informing 

potential risk-based decisions about the RTR source category or categories in question. While we 

recognize that, because these risk estimates were derived from facility-wide emissions estimates 

which have not generally been subjected to the same level of engineering review as the source 

category emission estimates, they may be less certain than our risk estimates for the source 

categories in question, they remain important for providing context, as long as their uncertainty 

is taken into consideration in the process. 

Further, for the two RTRs we are finalizing, our evaluation of facility-wide risk did not change 

our decisions about acceptability and ample margin of safety for these two source categories. 

Therefore, comments on how this factor was used by EPA in determining acceptable risks are 

not germane to these final rules. We note, however, that section 112(f)(2) of the CAA expressly 

preserves our use of the two-step process for developing standards to address residual risk and 

interpret ―ample margin of safety‖ as developed in the Benzene NESHAP. In both the Benzene 

NESHAP and our Residual Risk Report2to Congress, we explain that we do not define ―rigid 

line(s) of acceptability‖ and that we will consider a series of other health measures and factors in 

determining if risk is acceptable. 

As stated in the Benzene NESHAP, in determining the need for residual risk standards, in the 

risk acceptability determination , we strive to limit to no higher than approximately 1-in-10 

thousand (100 in a million) the estimated cancer risk that a person living near a plant would have 

if he or she were exposed to the maximum pollutant concentrations for 70 years and, in the 

ample margin of safety determination, to protect the greatest number of persons possible to an 

individual lifetime risk level of no higher than approximately 1-in-1 million. These 

considerations are made for all people regardless of racial or socioeconomic status. In 

 

2

See Residual Risk Report to Congress, EPA–453/R–99–001 (March 1999).
12

determining whether to require additional standards, these levels are not considered rigid lines, 

and we weigh the cancer risk values with a series of other health measures and factors in both the 

decision regarding risk acceptability and in the ample margin of safety determination. We also 

consider cost of controls in the ample margin of safety determination. While we provided a 

demographic analysis of populations surrounding the facilities in the source categories addressed 

by these RTRs and found some demographic differences in exposed populations compared to 

nationwide estimates, the results of our demographic analysis only serve to provide information 

about the demographic make-up of the populations exposed to each of these source categories 

which might benefit from the proposed rules. Our authority to use the two-step process laid out 

in the Benzene NESHAP, and to consider a variety of measures of risk to public health is 

discussed more thoroughly in the preamble to the proposal. See 75 FR 80222 – 80225.

7. Comment: Commenter 45 agreed with EPA in the removal of the unlawful malfunction 

exemption under the existing rules but noted that EPA failed to consider increased acute health 

risks and possibly chronic risk from malfunction or other violations of the MACT standard.

EPA must consider data regarding the use of the SSM exemption and enforcement 

actions in the past, at minimum, and other information it has regarding the history or 

likelihood of malfunctions or other violations of the standard, as part of its analysis. 

EPA must recognize that a certain level of malfunctions and other violations of the 

MACT is likely, and factor this into its analysis of the risk to public health and the 

environment.

Failing to look at the true potential for spikes will significantly underestimate the 

amount of emissions considered for this analysis. The Act specifically requires EPA 

to base its risk analysis on the highest possible level of risk – i.e., the risk ―to the 

individual most exposed to emissions from a source in the category or subcategory.‖ 

42 U.S.C. § 7412(f)(2)(A). To do this, it is necessary for EPA to determine the 

highest level of potential emissions from the worst-performing source, and then use 

that information to establish the maximum individual risk. That requires 

consideration of malfunction- and other violation-based emissions.

Research by the Environmental Integrity Project (―EIP‖) from 2004 found that 

significant emission exceedances occur routinely, across a range of different 

industries. Moreover, EIP found that ―releases from upsets actually dwarf a facility‘s 

routine emissions. EPA must look at data, like the EIP report, and ensure that its risk 

analysis and resulting standard prepare for the likelihood that malfunctions will occur 

and that the public will need protection from the high emissions they cause.

Response: We believe SSM events do not contribute significantly to chronic cancer or 

noncancer risks for the source categories. SSM events for these source categories are inherently 

short-term and infrequent relative to continuous annual operations and emissions. The 

commenter did not supply any data to the contrary that would change the acute multipliers 

calculated for these source categories that would lead us to believe that peak modeled hour 

events are under-estimated. See response to comments in Section I.B. (SSM provisions) for 

additional information on expected infrequency of SSM events.
13

8. Comment: Commenter 45 pointed out that EPA may not set any HAP risk level at zero. 

The commenter noted that Section 112(f)(2) of the CAA creates a critical duty and opportunity 

for EPA to conduct a comprehensive and protective analysis of residual risk to public health and 

the environment. It is a serious problem for EPA‘s analysis that ―some HAP continue to have no 

reference values.‖ 75 Fed. Reg. at 80,234. 

Even over twenty years after the Clean Air Act was amended, sufficient studies for 

some HAPs have not been conducted to allow calculation of reference doses or 

reference concentrations or potency values. Moreover, the IRIS process has bogged 

down. As the Center for Progressive Reform has recognized, EPA should prevent the 

delay in this process from undermining its residual risk analysis. It should prioritize 

those HAPs for which it needs data in this rulemaking and the next upcoming 

rulemakings and ensure that the development of this process and IRIS review have 

sufficient funding and resources to get the job done.

Even if no reference values are available, this does not justify EPA setting the risk at 

zero for any HAP. EPA must address this uncertainty by selecting a health-protective 

value based on what is known so that it may consider the potential risk and find an 

appropriate way to address that risk in this rulemaking. 

EPA should make this issue a priority for the National Toxicology Program or ensure 

that the data are generated by another means. If data are available to support the 

derivation of a reference concentration and potency estimate, or the IRIS process is in 

progress but not yet complete, EPA should put these compounds on a priority to 

complete the IRIS process. EPA must also set a regulatory deadline, such as four or 

eight years from the finalization of these rules, when it shall commit again to review 

the current residual risk analysis and again perform a residual risk rulemaking once 

additional data become available. It is not enough for EPA to say that it will 

potentially revisit this issue. It must set a regulatory deadline for this action that 

citizens can help enforce.

Two commenters contended that EPA considered factors that might lessen the concern for 

risks, but did not give equal weight to factors that increase concern. For example, the 

EPA‘s analysis ignored HAP for which the Agency lacks cancer potency values.

Response: This issue was addressed by the EPA‘s Science Advisory Board (SAB) in 

their May 10, 2010, (EPA-SAB-10-007) response to the EPA Administrator; 

http://yosemite.epa.gov/sab/sabproduct.nsf/4AB3966E263D943A8525771F00668381/$File/EPA

-SAB-10-007-unsigned.pdf. In that response, the SAB Panel recommended that, for HAPs that 

do not have dose-response values from EPA‘s hierarchy list, EPA should consider and utilize, as 

appropriate, additional sources for such values that have undergone adequate and rigorous 

scientific peer review. They further recommended that the inclusion of additional sources of 

dose-response values into the EPA‘s hierarchy should be adequately documented in a transparent 

manner in any residual risk assessment case study. We agree with this approach and have 

considered other sources of dose-response data when conducting our risk determinations under 

RTR.
14

The SAB Panel and EPA also agree that the EPA should ultimately develop toxicity values for 

all Hazardous Air Pollutants (HAPs) utilizing all credible and relevant toxicity information. The 

need to update assessments with newly available data as well as the need to complete 

toxicological assessments for all HAPs lacking dose-response assessments further increases the 

importance of Agency activities to streamline and fully utilize the EPA‘s already overloaded 

IRIS program. To that end, EPA has always prioritized for future IRIS assessments those HAP

without dose-response values but with the greatest potential for public exposure. As a result of 

this prioritization, while not all HAPs may have scientifically accepted dose-response values that 

can be used in residual risk assessments, it is clear that the vast majority of HAPs which might 

carry the potential to significantly impact the results of residual risk assessments do, in fact, have 

credible dose-response values. Thus, while we are not yet at the point where all HAPs have 

dose-response values, we are generally capable of deriving reasonable risk estimates for those 

HAP which dominate the risks from any one source category. In the course of each residual risk 

assessment, should we encounter HAP without dose-response values which carry the potential to 

create significant risks, we shall clearly point those out as uncertainties and target them for future 

IRIS assessments.

9. Comment: Commenter 45 noted that EPA understated risk by not addressing the health 

risks posed by clusters of facilities within each of the source categories. The commenter 

referenced EPA‘s residual risk assessment for the synthetic organic chemical manufacturing 

industry (SOCMI). The assessment noted that while ―HEM-3 models one facility at a time . . . 

another facility nearby may impact the same people, resulting in higher risk to those people (i.e., 

the cluster effect).‖ See EPA, SOCMI - Residual Risk Assessment (EPA-HQ-OAR-2005-0475-

0108), at 4-9 (Sept. 2005). 

The commenter opined that EPA could easily replicate its SOCMI cluster analysis for both of the 

source categories evaluated in the agency‘s current proposal. The SOCMI cluster analysis was 

developed using the outputs from HEM-3. EPA‘s proposal for shipbuilding and ship repair and 

for wood furniture manufacturing relies on the same model and outputs. EPA should utilize 

―allowable‖ emissions in calculating the cluster risks. Such clusters of facilities likely impact the 

MIR; if not, they almost certainly increase other health risks faced by individuals living within 

50 km of more than one facility.

Response: In our current risk modeling methodology, which has been updated since we 

performed the analyses for the SOCMI HON RTR, overlapping risks for the same source 

category are automatically included in determining the MIR, incidence, etc. Any risks from 

clusters of facilities in the source categories investigated were included in the reported results of 

the analysis for the source category.

10. Comment: Commenter 45 stated that EPA failed to consider or account for cumulative 

risk. According to the commenter, there is no rational or scientific basis to dismiss consideration 

of the cumulative risk of exposures to HAPs due to uncertainties. The commenter urged that 

these uncertainties require protective action rather than inaction. The commenter continued:

As EPA recognizes, the SAB in May 2010 urged it to use the RTR rulemaking process to do this 

as well as perform a sensitivity analysis to identify the major uncertainties in both the human 

health and ecological risk assessments. The SAB and numerous other scientific experts have 
15

developed, and are in the process of developing, cutting edge methods to perform these 

assessments. EPA, as the lead environmental agency of the United States, has a responsibility to 

show leadership in this process. It should rely on the significant information already available, 

and also use the current and future RTR rulemakings to further advance this process.

The commenter stated that it could be done on a site-specific basis or it could be done for the 

industry as a whole. Uncertainty in estimates of HAPs in ambient air has been characterized, so 

the data available from the NATA would allow a defensible estimate of what might be expected 

from other sources.

Response We disagree with the comment that we failed to consider or account for cumulative 

risk. EPA modeled whole-facility risks for both chronic cancer and non-cancer impacts to 

understand the risk contribution of the sources within this MACT category and those attributed 

to other emission sources. The individual cancer risks for each source category 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 

target-organ-specific hazard index (TOSHI), defined as the sum of hazard quotients for 

individual HAPs 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). Whole facility risks were estimated utilizing the 2005 NEI, 

with updated facility-wide and source category data files developed by EPA thru emission data 

updates from industry, 2005 NATA updates, and refined EPA profiles for this source category. 

We further disagree with the commenter‘s assertion that additional quantitative assessment of 

risks from sources outside the source category is required under the statute. Instead, to provide 

the quantitative risk information necessary to inform RTR regulatory decisions, EPA conducts a 

comprehensive assessment of the risks associated with exposure to the HAPs emitted by the

source category and supplements that with additional information that is available about other 

possible concurrent and relevant risks. In some cases, we have additional information about 

HAP emissions from outside the source category but within the boundaries of the subject 

facilities. In other cases, we may have ambient HAP monitoring data. In still other cases, we 

may have very little additional risk information. In all cases, however, when we consider 

additional information about risks, we also consider its attendant uncertainties, and information 

which carries significant uncertainties generally carries less weight in the regulatory decision.

11. Comment: Commenter 45 stated that EPA must consider and account for the higher risk 

created for vulnerable individuals. 

There is a particular need for EPA to address and incorporate the new science on vulnerable 

individuals, including youth, into its risk analysis. For example, as the Science Advisory Board 

has pointed out to EPA: ―California‘s Office of Environmental Health Hazard Assessment 

(OEHHA) has recently updated its methodology in ways that could affect the development of 

RfC and URE values. EPA should examine these developments to make sure that the RTR 

process adequately covers children‘s risks.‖ SAB May 2010 at 6, 34. EPA‘s inhalation analysis 
16

should also address the higher chronic risk that children face from inhalation. EPA should 

address and incorporate this higher level of risk into its residual risk analysis.

Where EPA has information that there is a greater risk when exposure occurs at a young age or 

during the prenatal period, it must analyze that risk for the source category and create a lifetime 

exposure analysis that recognizes that risk susceptibility is greater due to the earlier exposure.

Commenter 45 recommended that EPA reassess environmental impacts using current scientific 

research. The commenter cited the following references (and included them as appendices to the 

comments):

[1] Risk Assessment Guidance for Superfund: Volume I. Human Health Evaluation 

Manual (Part A). Interim Final. Washington DC. Office of Solid Waste and 

Emergency Response, US Environmental Protection Agency; October 1989. 

http://www.epa.gov/oswer/riskassessment/ragsa/index.htm.

[2] Linda K. Teuschler and Richard C. Hertzberg. 1995. Chemical mixtures and 

quantitative risk assessment: Current and future risk assessment guidelines, 

policy, and methods development for chemical mixtures. Toxicology Volume 

105, Issues 2-3, 28 December 1995, Pages 137-144. doi:10.1016/0300-

483X(95)03207-V.

[3] Framework for Cumulative Risk Assessment 1-3, EPA/630/P-02/001F (May 

2003) 

[4] National Research Council. 2008. Phthalates and Cumulative Risk Assessment: 

The Tasks Ahead. Executive Summary.

The commenter also recommended EPA focus on populations that may be more susceptible to 

environmental factors:

The issue of more susceptible populations has been another target of investigative and 

policy developments over recent decades. Efforts developed in response to the Food 

Quality Protection Act of 1996 led to the agency taking actions to cancel uses of 

pesticides in case when the aggregate risk from different sources of pesticides were 

too great. This reflects the scientific consensus that people are not exposed to only 

one thing at a time and that assessments must reflect the biological reality in which 

people live. It also reflects the new scientific understanding, as stated by the National 

Academy of Sciences, that ―children are not little adults‖ (National Research Council. 

1993. Pesticides in the Diets of Infants and Children. Committee on Pesticides in the 

Diets of Infants and Children. Board on Agriculture and Board on Environmental 

Studies and Toxicology. Commission on Life Sciences. National Academy Press. 

Washington, D.C (attached in Appendix)). Prior to this time, methods for assessing 

chemicals hazards and risks had largely ignored children and considered them to 

simply be smaller adults. This report pointed out that the developmental process, 

which begins in the womb, before birth, is exquisitely sensitive to chemicals because 

it is directed by chemical signals in the body. Myriad organs, systems, and processes 

have to develop, grow, and connect correctly during the development process, which 
17

extends into early adulthood. These processes can be easily disrupted by chemical 

exposures. The idea of a ―lifetime dose‖ of a chemical that would correspond to a 

1-in-1 million cancer risk is largely irrelevant for children. They can be affected by 

doses over much shorter periods of time and that are much lower than what would 

affect adults. This has implications, obviously, for the residual risk program, none of 

which EPA seems to recognize.

EPA and the public now have significant information on the greater vulnerability to 

pollution faced by children and the elderly. California has developed child-specific 

reference doses to address the greater risks affecting children . Science shows that 

―[e]nvironmental contaminants can affect children quite differently than adults, both 

because children may be more highly exposed to contaminants and because they may 

be more vulnerable to the toxic effects of contaminants.‖ Recently, EPA‘s Children‘s 

Health Protection Advisory Committee has recommended addressing the 

developmental origins of adult disease that come from childhood exposure to air 

pollution and other environmental contaminants. Similarly, the Committee has 

recommended that EPA incorporate a more robust analysis of childhood and prenatal 

exposure to environmental contaminants into its risk assessment method. The greater 

understanding today of the higher risk to children and other vulnerable groups, like 

the elderly, which environmental pollution creates is likely to affect the public‘s view 

of what level of environmental risk is acceptable today. These new studies speak to 

numerous EPA acceptability factors. For example, for factors one to three, these 

studies give EPA significant knowledge (factor 3) that there is both greater ―certainty 

and severity of the risk‖ for children (factor 1) and that the effects are particularly 

likely to be harmful (and not reversible) when there is early exposure (factor 2).

In addition to new data on children‘s particular vulnerability to environmental 

hazards (and the long-term effects of early exposure), EPA now has greater 

knowledge of the toxic body burden of healthy adults. This is also relevant to the 

consideration of EPA‘s acceptability factors one through three. For example, in the 

most recent 2010 national biomonitoring report, the Center for Disease Control stated 

that it had found 212 chemicals present in people‘s bodies, including 75 chemicals 

never before found in human beings. This new information has led to changes in 

behavior and calls for reform ranging from demands for greater protection from 

toxics in kitchen products and water and baby bottles, to changes in eating habits that 

aim to avoid contaminants like mercury in fish and drinking water through filters, to a 

greater consumption and market for pesticide-free food. These examples show how 

new science has affected the public‘s growing concern about environmental health 

risks, of which EPA is well aware. These changes represent a further shift downward 

in the level of risk that the public deems acceptable from the unnecessary intake of 

toxic chemicals, whether through the air, water, or food.

Response: We acknowledge that population subgroups, including children, may have the 

potential for risk greater than the general population due to greater relative exposure and/or 

greater susceptibility to the toxicant. As explained in previous actions, including the final 

SOCMI HON RTR, the assessments we undertake to estimate risk account for this potential 

vulnerability. With respect to exposure, the risk assessments we perform implicitly account for 

this greater potential for exposure by assuming lifetime exposure, in which populations are 
18

conservatively presumed to be exposed to airborne concentrations at their residence 

continuously, 24 hours per day for a full lifetime, including childhood. With regard to children‘s 

potentially greater susceptibility to non-cancer toxicants, the assessments rely on Agency (or 

comparable) hazard identification and dose-response values which have been developed to be 

protective for all subgroups of the general population, including children. For example, a review3

of the chronic reference value process concluded that the Agency‘s reference concentration 

(RfC) derivation processes adequately considered potential susceptibility of different subgroups 

with specific consideration of children, such that the resultant RfC values pertain to the full 

human population  ̳ ̳including sensitive subgroups,‘‘ a phrase which is inclusive of childhood.

On the issue of cancer dose-response values, EPA‘s revised cancer guidelines and supplemental 

guidance recommend applying default adjustment factors to account for exposures occurring 

during early-life exposure to those chemicals thought to cause cancer via a mutagenic mode of 

action.4For these chemicals, the supplemental guidance indicates that, in lieu of chemicalspecific 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 earlylife exposures to chemicals which cause cancer through a mutagenic mode. At the present time, 

there have been no peer-reviewed assessments that explicitly make a determination that any of 

the chemicals emitted by the source categories considered in this action cause cancer via a 

mutagenic mode of action. However, the estimated risks must also be considered in the context 

of the full set of assumptions used for this risk assessment. For example, we used a healthprotective assumption of a 70-year exposure duration in our risk estimates; however, using the 

national average residency time of 12 years would reduce the estimate of risk by roughly a factor 

of 6. Our unit risk estimates for HAP are considered a plausible upper-bound estimate; actual 

potency is likely to be lower and some of which could be as low as zero. After considering these 

and other factors, we continue to consider the risks from emissions after application of the 

MACT standards for these source categories to provide an ample margin of safety (within the 

meaning of the Benzene NESHAP decision framework). 

12. Comment: Commenter 45 disagreed with EPA‘s reliance on the Benzene Rule‘s 

presumption that a 100-in-1 million lifetime cancer risk is acceptable today, as this fails to 

account for evolving science and societal standards. EPA can no longer presume that the level of 

risk that is acceptable has remained the same since 1988, when it promulgated the Benzene Rule.

To address the court‘s direction to consider context and what is ―acceptable in the 

world in which we live,‖ at the time of the Benzene rule, EPA performed a Survey of 

Societal Risk (July 1988) to consider various types of health risks at that time. Id. at 

28,513. [EPA] relied on this study to set a presumptive limit on maximum individual 

lifetime risk (MIR) of approximately 1-in-10 thousand, or 100-in-1 million people, as 

a benchmark (but not a ―rigid line‖). 54 Fed. Reg. at 38,045. In establishing this 

presumptive benchmark, EPA assumed that the maximum exposed individual was a 

person out of context. It did not consider the potential that different persons, at the 

same exposure level, might face different levels of risk. To choose this number, EPA 

 

3A Review of the Reference Dose and Reference Concentration Process. U.S. Environmental Protection Agency. 

Risk Assessment Forum. EPA/630/P–02/002F. December 2002.

4

―Guidelines for Carcinogen Risk Assessment,‖ (EPA/630/P-03/001F), March 2005; and ―Supplemental Guidance 

for Assessing Susceptibility from Early-Life Exposure to Carcinogens,‖ (EPA/630/R-03/003f), March 2005. 
19

considered a broad range of risks, such as driving a car and breathing air, and found 

that ―the presumptive level established for MIR [maximum individual risk of cancer] 

of approximately 1 in 10 thousand is within the range for individual risk in the 

survey, and provides health protection at a level lower than many other risks common 

‘in the world in which we live.‘‖ Id. at 38,046 (emphasis added). Even so, EPA 

recognized that it could not easily compare the presumption it chose and many of the 

risk levels studied because of numerous differences. Specifically, EPA stated that the 

consideration of the acceptability of a specific level of risk depends on factors 

including: [1] [t]he certainty and severity of the risk; [2] the reversibility of the health 

effect; [3] the knowledge or familiarity of the risk; [4] whether the risk is voluntarily 

accepted or involuntarily imposed; [5] whether individuals are compensated for their 

exposure to the risk; [6] the advantages of the activity; and [7] the risks and 

advantages for any alternatives. 53 Fed. Reg. at 28,513. Although this is not a 

comprehensive list of factors that EPA must consider, the fact that so much has 

changed to affect these factors demonstrates that, even within EPA‘s original 

analysis, the presumptive level of what risk is acceptable requires a reduction.]

EPA still applied the acceptability presumption developed from that 1988 survey in 

this proposal to determine that the level of risk for both shipbuilding and ship repair 

and wood furniture is ―acceptable.‖ 75 Fed. Reg. at 80,238, 80,245. The ongoing use 

of the 1988 presumption, that risk below 100-in-1 million is acceptable, today, in 

2011, is arbitrary and capricious for numerous reasons.

Commenter 45 further noted that EPA does not justify its conclusion that this level of risk is 

acceptable. EPA recognizes that disparities in risk exist, with certain demographic groups, 

including Hispanics, people living below the poverty line, and people over age 25 without a high 

school diploma, more likely to experience a higher level of risk. The commenter urged EPA not 

to rely on the old Benzene presumption that any level of risk under 100-in-1 million is 

acceptable. Section 112(f)(2) requires EPA to set standards for the maximum exposed individual 

and it has not adequately supported its analysis that the level of residual risk for this source 

category is acceptable. Commenter 45 states the document "Survey of Societal Risks" was not 

obtainable from the EPA Air docket.

Relying on this type of out-dated presumption contravenes the purpose of section 

112(f)(2) which is to make regulatory changes based on what EPA, and the public, 

have learned from the implementation of the MACT standard. Section 112(f)(2) 

explicitly requires EPA to assess residual risk within 8 years after promulgation of the 

MACT standard. 42 U.S.C. § 7412(f)(2)(A), (C). This allows time for the MACT 

standard to take effect and ensures that EPA must assess that impact, including the 

acceptability factors, to see what pollution and environmental health impacts remain 

after implementation of the MACT, and to consider whether or not the residual risk is 

acceptable in the contemporary view.

The review for residual risk is a key moment within the statutory framework for 

HAPs when public health must be considered. It provides an overarching review of 

whether public health is protected through application of the technologies specified 

through the MACT process. Technological development may or may not be sufficient 

to protect public health. The advantage of technology-based standards is that they are 
20

relatively easier to implement because they require only assessment of whether 

technologies exist. But at some point the question of whether they protect public 

health must also be asked, and that is the express purpose of the residual risk review.

The residual risk analysis requires a fresh look at whether there is a need for more 

stringent pollution controls to protect public health and the environment. That 

includes a current look at what the contemporary view of ―acceptable‖ risk is, in 

relation to environmental pollution. By requiring the 8-year review, Congress 

inherently directed EPA to act based on and to take account of new, future 

circumstances that EPA had not considered in promulgating the initial standard. If 

EPA were allowed to go back in time to a single snapshot view of what was 

―acceptable‖ from 1988, forever, this would undermine the Act‘s goal of ensuring an 

evolving, improved approach to pollution control through the review and revision 

process.

As pollution-control technology and industrial practices have evolved to be able to 

better protect human health, their evolution has also changed the ―world in which we 

live‖ and with it, the public‘s views on what level of risk may be acceptable (or not). 

The fact that other lower emission or lower-risk coatings or technologies are now 

available must be considered, regardless of cost, as a factor in determining whether 

the old presumption about risk acceptability (i.e., that a cancer risk below 100-in-1 

million could be acceptable) still applies. Where cancer risks from a specific polluting 

source can be further reduced using available technologies, and indeed, where another 

jurisdiction has already required this to happen, EPA cannot justify continuing to 

expose a child today to a level of risk simply because it was considered to be 

acceptable decades ago.

In sum, for all of these reasons, even looking only at EPA‘s own list of acceptability 

factors, EPA cannot assume that Americans today would consider a lifetime cancer 

risk below 100-in-1 million to be acceptable (even assuming it once was). This is an 

especially poor assumption for environmental exposure that is completely out of a 

person‘s control and is most likely to affect people who have the least ability to 

escape this type of pollution due to socioeconomic factors. If EPA wishes to use some 

presumptive level of risk in its residual risk review, EPA must assess risk ―in the 

world in which we live,‖ both by addressing evolving science and performing an 

updated assessment of contemporary values. The world has changed so dramatically 

since 1988 that EPA can have no rational justification for continuing to apply the 

Benzene rule‘s 100-in-1 million presumption, automatically, based on the 1988 

Survey, to the source categories under review.

Although in the HON case the D.C. Circuit affirmed EPA‘s use of certain elements of 

the Benzene rule, it did not rubber stamp the Benzene Rule‘s approach in full. The 

court‘s interpretation of CAA § 112, stating that Congress incorporated the Benzene 

approach in the 1990 CAA Amendments, is limited to the issue raised in that case by 

petitioners: specifically, whether subsection 112(f)(2)(A) required EPA to revise 

standards to reduce lifetime excess cancer risk to 1-in-1 million. NRDC v. EPA, 529 

F.3d 1077, 1081 (D.C. Cir. 2008). The court held that this was not required under the 

statute, finding that ―the Benzene standard established a maximum excess risk of 100-

in-one million, while adopting the one-in-one million standard as an aspirational 
21

goal.‖ Id. at 1082 (emphasis added). The HON court did not address the questions 

raised in this rulemaking. It also did not broadly hold that EPA can do in every future 

residual risk rulemaking precisely what it did at each step of the Benzene NESHAP. 

By urging EPA to continue to ―aspire‖ to reach the 1-in-1 million level, it implicitly 

recognized that 100-in-1 million was a maximum, such that EPA should continue 

striving to reduce risk over time and in context.

A lifetime cancer risk below the level of 100-in-1 million can no longer be considered 

―safe‖ or ―acceptable‖ in ―the world in which we live‖ (i.e., the contemporary 

standard required by the D.C. Circuit that the HON court left undisturbed). 

Specifically, EPA must reassess whether a level below 100-in-1 million and closer to 

the ―aspirational goal‖ of 1-in-1 million should be adopted as a more stringent, 

presumptive outward limit for what is considered ―acceptable.‖ This is a question that 

EPA cannot evade by attempting to rely on the different issue addressed in the HON 

case, or on the overbroad theory that everything it did in the Benzene Rule is per se 

lawful – for all time and all source categories – even when, as here, circumstances 

have changed so dramatically.

Each of the significant findings of the above-described new research greatly 

undermines the idea that an MIR below 100-in-1 million could still be considered an 

acceptable level for environmental health risks, in every context. 

The commitment to environmental justice must inform EPA‘s evaluation of 

―acceptable‖ risk. During the last two decades, American values have evolved to 

consider the issue of environmental justice and to acknowledge and address 

disproportionate environmental health impacts. It is a shameful, longstanding reality 

that much more toxic pollution in this country has been sited[sic] in or near particular 

communities and urban neighborhoods that have higher minority and lower-income 

populations. 

These important concerns all affect EPA‘s consideration of the acceptability factors, 

including the greater knowledge of the certainty and severity of the risk for certain 

communities, especially where cancer is the potential health effect (i.e., often 

irreversible). Environmental justice should also inform the question of how 

acceptable it is today for disproportionate risks to be ―involuntarily imposed,‖ 

without compensation, where there are alternatives.

Response: As an initial matter, we note that in 1990 Congress codified in section 112(f) of 

the CAA the approach we use for our residual risk analyses. Under that approach, the 100 in a 

million cancer risk is not a bright line indicating that risk is ―acceptable,‖ but rather we consider 

this health metric in conjunction with a variety of health factors to determine whether the risk is 

acceptable. Where we conclude that the risk is not acceptable, we cannot consider costs in 

requiring controls to bring risks down to an acceptable level. However, the analysis of whether 

risk is acceptable is not the endpoint. Once we determine that controls are sufficient to ensure 

risk is acceptable, we again review the health metrics in conjunction with considering the costs

of controls to determine whether additional controls should be required to provide an ample 

margin of safety. 
22

Moreover, the commenter does not support its contention that people are now unwilling to accept 

a level of risk that was acceptable at the time the CAA was amended in 1990. Nor does the 

commenter support how science has evolved in a way that would undermine the codified 

framework for determining acceptability. EPA notes that Commenter 45 obtained a copy of 

"Survey of Societal Risks" from the Air Docket subsequent to filing comments in this 

rulemaking. EPA has added the document, from OAQPS Docket 79-3, Docket Item X-B-1, to 

the docket for this rulemaking. We note that for purposes of the proposed rule, we performed 

demographic (environmental justice) analysis for the purpose of informing the public, and that 

analysis is in the docket.

13. Comment: Commenter 45 suggested that EPA include a plain-language statement of the 

health risks and benefits from EPA‘s proposed action.

As part of determining whether these risks are ―acceptable,‖ EPA should include a 

plain statement of the risks at issue. Although it provides the MIR and chronic and 

risk numbers, these are not easily understandable by the general public. EPA does not 

state in the rule proposal the types of cancer or the nature of the health disorders or 

other adverse effects that these risks represent to the public. For example, although it 

states that the reproductive system and nervous system are at particular risk for these 

source categories, it does not describe, analyze, or explain what types of effects these 

would be, or put this in terms that the public can understand. If particular people are 

more likely to be susceptible to such risks, such as children, elderly, women of 

childbearing age, individuals with preexisting diseases, EPA should also discuss this, 

as the SAB has urged it to do. SAB May 2010 at 50.

This type of ―[e]xpanded discussion is important to understanding the  ̳real-world‘ 

risk, including dealing with health disparities. For example, it would be important to 

recognize if a risk driver for a particular facility exacerbated asthma and the 

community surrounding the facility was a low-income population with an elevated 

incidence of asthma.‖ Id. If a small number of people are exposed at a high risk to an 

extremely debilitating disease, this may make a level of risk unacceptable, or require 

a larger ―margin of safety‖ than might be true in a different circumstance. Yet, EPA 

does not even list the health problems at issue with the emissions from these source 

categories, including xylenes, ethyl benzene, toluene, formaldehyde or glycol ether 

emissions. Doing so is necessary to fully evaluate the risks (and to demonstrate the 

value of the new residual risk standard that EPA is proposing). Without this, it is 

difficult for the public to provide meaningful comment, such as on EPA‘s proposal 

not to set a standard for shipbuilding and ship repair and not to set a standard for 

glycol ether emissions from wood furniture manufacturing operations. EPA should 

provide a statement and analysis in this residual risk rulemaking and all others on the 

―real world‖ health effects at issue in the rulemaking, so that the public has a clear 

understanding of what the risk is, and precisely what types of harm to public health 

EPA is determining are either ―acceptable‖ or ―unacceptable.‖

Response: It is EPA‘s goal to make all rule preambles and risk assessments in plain 

language. The documents have been made to be in plain language as much as possible.
23

14. Comment: Commenter 46 suggested that EPA delist all source categories that EPA 

believes meet Section 112(c)(9) criteria and use Title V to enforce emission limits and standards 

as part of Section 112(c)(9) delisting: 

Section 112(c) requires EPA to list and regulate, on a prioritized schedule, ―all 

categories and subcategories of major sources and areas sources‖ that emit one or 

more hazardous air pollutants. 42 U.S.C. §7412(c)(1). EPA may delete any source 

category from the list under this subsection, on petition of any person or on its own 

motion, whenever it determines the source category meets certain criteria. Id. 

§7412(c)(9). To the extent EPA‘s risk assessment finds the source category (or 

subcategory) has low risk, EPA should delist the source category (or subcategory). If 

not delisted and EPA finds that it may continue to revise the standard based on new 

technologies (which we dispute), sources will be subject to an endless technology 

ratchet, uncertainty and costs as new technologies are developed. All despite the fact 

that the sources within the category pose little risk, if any, to the public. EPA has 

recognized the availability of section 112(c)(9) ―to remove the burden of the 

repetitive review of Section 112 standards for low risk source categories.‖ 71 Fed. 

Reg. 17,729, 17,735 (Apr. 7, 2006). We support EPA‘s determination to investigate 

approaches for removing low-risk source categories from the section 112 universe. Id. 

Delisting is appropriate even after MACT standards have been in place. Section 

112(c)(9) expressly states EPA has the authority to delist categories ―whenever.‖ 

Moreover, the residual risk review comes after EPA issues a MACT standard, and 

EPA should be allowed to use the residual risk review under section 112(f) to 

determine if the source should now be delisted. EPA has previously delisted sources 

based on a finding that emissions were significantly lower than previously estimated, 

posing reduced risks. 60 Fed. Reg. 61,550 (Nov. 30, 1995) (delisting asbestos 

processing area source category). This decision was based, in part, on findings that 

U.S. processors currently employ very effective baghouse collection methods and 

these ―control methods will continue to be employed even after the area source 

category is delisted.‖ Id. at 61,551; see also 61 Fed. Reg. 30,816, 30,821 (June 18, 

1996) (delisting pollutant where facility agreed to limit emissions below certain risk 

level). Those elements of the MACT standard that might be needed to sustain the low 

risk determination and could be established as part of the source category delisting 

decision. These requirements could be enforceable and maintained in existing Title V 

permits to ensure the public health protection contemplated by section 112(c)(9).

Response: Based on our risk assessment of the Wood Furniture Manufacturing and the 

Shipbuilding and Ship Repair (surface coating) source categories, we did not find that these 

source categories have low risk with cancer risks below 1 in a million. The cancer risks from 

these sources are considered acceptable with MIRs of 10 in a million, and the existing MACT

standards provide an ample margin of safety to protect public health. In addition, for wood 

furniture manufacturing, we are adopting additional standards under 112(d)(6), as explained 

elsewhere in this document and the preamble to the final rule. Therefore, delisting these source 

categories would not be appropriate based on the risk estimates. We note that we have previously 

discussed our position on delisting low-risk source categories in the final residual risk action for 

the Magnetic Tape Manufacturing Operations source category (71 FR 17724).
24

15. Comment: Commenter 45 stated EPA has provided no rational explanation for refusing to 

update the technology standards for both categories to meet the CAA § 112(d)(6) requirement, at 

minimum, by matching the limits of what sources have achieved and what other jurisdictions 

have required. 

We urge EPA to do so in the final rule. Where, as here, there are ―significant 

developments‖ in technology, and where, as here, sources have achieved lower levels 

of emissions ―in practice‖ than are ―MACT-allowable,‖ it is abundantly clear that § 

112(d)(6) requires EPA to revise its standards in accordance with CAA § 112(d)(2)-

(3), (6), 42 U.S.C. § 7412(d)(2)-(3), (6).

Response: The EPA has concluded the technology review for the wood furniture 

manufacturing operations NESHAP by setting a formaldehyde limit based on formulation (1 

percent by weight) of finish coatings and contact adhesives with a compliance alternative of

using no more than 400 pounds of formaldehyde per 12 months. Also under the technology 

review we are adopting a restriction of conventional spray guns limiting use to when emissions 

from finishing applications are routed to a control device. The commenter refers to volatile 

organic compounds (VOC) standards of the Bay Area and South Coast Air Quality Management 

Districts (BAAQMD and SCAQMD). These two standards are nearly identical in VOC 

formulation limits. Through the RTR process, the EPA evaluates risk and technology 

developments associated with HAP for the source categories under consideration. HAP and VOC 

describe different sets of compounds, although a large subset of VOC are considered HAP. As 

discussed in the preamble of the proposed rule, we estimate that of all VOC in wood furniture 

coatings, 50 percent on average are HAP. This is an average value that in fact varies from facility 

to facility and coating to coating, depending on the facility‘s use of coatings specific to their 

operation. This is especially true for many niche companies. The EPA acknowledges BAAQMD 

and SCAQMD implementation of VOC limits, but these limits are not justified as nation-wide 

standards to reduce HAP from Wood Furniture Manufacturing. They are not technically feasible 

to be implemented nationally based on different operating and environmental conditions as well 

as based on the cost effectiveness. By the commenter‘s own admission, there are facilities that 

are having a difficult time complying with the BAAQMD standard within its region. Moreover, 

based on available information, the EPA maintains that both area regulations are not cost 

effective as national standards to reduce HAP. As discussed in the preamble to the proposed rule, 

adoption of the BAAQMD VOC limits would result in 56 tpy of HAP reduction at a cost of 

$30,000 per ton. Although the commenter asserts based on a conversation with BAAQMD staff 

that companies in the area are generally complying with BAAQMD limits, EPA already assumed 

compliance when we estimated HAP reductions and cost effectiveness of the BAAQMD limits. 

We have not changed our conclusion that the BAAQMD and SCAQMD regulations are not cost 

effective as a national standard.

16. Comment: Commenter 45 stated that it is not rational or lawful for EPA to assume there is 

no potential for multi-pathway or environmental risks from HAP emissions. 

EPA recognizes that there is a human inhalation risk posed by the hazardous air pollutants 

emitted from both source categories. Yet ―multi-pathway exposures and environmental risks 

were deemed negligible‖ for both source categories. The minimal analysis EPA performed on 
25

this issue does not satisfy the statutory requirement ―to prevent . . . an adverse environmental 

effect.‖ 42 U.S.C. § 7412(f)(2)(A). 

EPA‘s approach is illogical and unlawful. Chemicals that are persistent in the environment and 

bioaccumulative in living tissue should not be evaluated on the basis of acute toxicity. The 

persistence of such chemicals means that their levels will increase over time, particularly in areas 

of high use. Accordingly, any additional exposure from current activities would thus be added to 

a background that is likely unsafe already.

Where there are human health risks from inhalation, it is unclear how, without analysis, EPA can 

conclude that there would be no effects either to wildlife or to natural resources in the 

environment either from inhalation or air deposition of HAP emissions, exacerbated by 

persistence and bioaccumulation. As the SAB has stated: ―The assumption that ecological 

receptors will be protected if human health is protected is incorrect.‖ SAB May 2010 at 48.

EPA must perform an appropriate ecological assessment. Its failure to do so here is especially 

problematic for shipbuilding and ship repair because these operations are likely to be located at 

or near a port, and very close to water.

Further, polycyclic organic matter (―POM‖), a carcinogenic HAP with a mutagenic mode of 

action that is emitted by facilities in both source categories, is a Great Waters pollutant of 

concern and EPA has previously noted that the section 112(f)(2) residual risk rulemaking is an 

important time to address this type of environmental risk.

EPA has recognized that the coatings at issue for these sources ―evaporate and can contribute to 

ground-level ozone and air pollution.‖ Doc. No. EPA-HQ-OAR-2010-0786-0023 at § 1.2 (Memo 

re: Developments in Practices, Processes, and Control Technologies for Wood Furniture 

Manufacturing Operations). Not only does ground level ozone result in harm to human health, it 

is also known to cause adverse environmental effects. In view of this, EPA must analyze the 

residual environmental effects, after the CAA § 112(d) standards are in place, and determine 

whether to set a standard to prevent this.

Finally, as the SAB recommended, EPA should include an analysis of both background and 

incremental risk. As the SAB has explained: ―[a] residual risk analysis that does not add 

exposures to baseline contamination to the estimates of on-going contamination may vastly 

underestimate the hazard quotient at the site and incorrectly conclude that the on-going releases 

pose risks at less than threshold levels.‖ SAB May 2010 at 41.

Response: Contrary to the commenter‘s assertions, we addressed the commenter‘s 

concerns as part of our multi-pathway exposure and environmental risk analyses. The potential 

for significant human health risks due to exposures via routes other than inhalation (i.e., 

multipathway chronic exposures) was screened by first determining whether any sources emitted 

any hazardous air pollutants known to be persistent and bioaccumulative in the environment 

(PB-HAP). Emissions of 3 different PB HAP were identified in the emissions inventory for the 

Wood Furniture Manufacturing source category; they are POM, lead, and cadmium. These 

emissions were evaluated for potential non-inhalation risks and adverse environmental impacts 
26

using the screening scenario which was developed for use with the TRIM.FaTE model. This 

screening scenario uses environmental media outputs from the peer-reviewed TRIM.FaTE model 

to estimate the maximum potential ingestion risks for any specified emission scenario by using a 

generic farming/fishing exposure scenario that simulates a subsistence environment. In the 

scenario, the farmer/recreational fisher was located at the point of the maximum impact to 

agricultural land near the hypothetical facility, and our assessment included the consumption of 

all types of home produced fruit, vegetables, beef, pork, and dairy products, as well as locally 

caught fish. The pathways included in this assessment were inhalation, soil ingestion, produce 

ingestion, fish ingestion, drinking water ingestion, and breast milk ingestion for infants. The 

farmer was assumed to consume locally caught fish at the rate of a recreational fisher, with highend consumption rates based on EPA values from the  ̳ ̳Exposure Factors Handbook‘‘ were 

included in the analysis to increase confidence that individuals that may have higher 

consumption would be protected.5 Risks were estimated using the health protective assumption 

of lifetime continuous exposures. The screening scenario retains many of the ingestion and 

scenario inputs developed for EPA‘s Human Health Risk Assessment Protocols (HHRAP) for 

hazardous waste combustion facilities.6In the development of the screening scenario a 

sensitivity analysis was conducted to ensure that its key design parameters were established such 

that environmental media concentrations were not underestimated, and to also minimize the 

occurrence of false positives for human health endpoints. For the purpose of developing emission 

rates for our multi-pathway screening, we derived emission levels for each PB HAP at which the 

maximum human health risk would be 1 in a million for lifetime cancer risk or a hazard quotient 

of 1.0 for noncancer impacts. The POM and cadmium emissions from the wood furniture 

manufacturing source category were at least 3 orders of magnitude below the emission rates for 

these two pollutants.

In evaluating the potential multi-pathway risks from emissions of lead compounds, rather 

than developing a screening emission rate, we compared maximum estimated chronic (3-month 

average) atmospheric concentrations with the current National Ambient Air Quality Standard 

(NAAQS) for lead. The maximum annual average off-site concentration of lead for this source 

category was 2 orders of magnitude below the NAAQS and was considered to have a low 

potential for multi-pathway risks. 

We evaluated the potential for significant ecological exposures to non PB-HAP from 

exceedances of chronic human health inhalation thresholds in the ambient air near these 

facilities. Human health dose-response threshold values are generally derived from studies 

conducted on laboratory animals (such as rodents) and developed with the inclusions of 

uncertainty factors that could be as high as 3000. As a result, these human threshold values are 

often significantly lower than the level expected to cause an adverse effect in an exposed rodent. 

It should be noted that there is a scarcity of data on the direct atmospheric impact of these HAPs 

on other receptors, such as plants, birds, and wildlife and that the EPA will continue to monitor 

the scientific literature for new data in this area. Thus, if the maximum inhalation hazard in an 

ecosystem is below the level of concern for humans, we have generally concluded that 

mammalian receptors should be at no risk of adverse effects due to inhalation exposures from 

 

5 EPA‘s Exposure Factors Handbook (Final); http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=12464

6 EPA‘s HHRAP for Hazardous Waste Combustion Facilities (Final); 

 http://www.epa.gov/osw/hazard/tsd/td/combust/risk.htm
27

non PB-HAP, and have assurance that other ecological receptors are also not at any significant 

risk from direct atmospheric impact. In some isolated cases where we have data indicating 

potential adverse impacts on plants, birds, or other wildlife due to the direct atmospheric impacts 

of specific HAPs, we note that as an uncertainty and, where possible, refine our analysis by 

comparing our modeled impacts to available threshold values from the scientific literature. The 

approach described here for evaluating human multipathway exposures and risks consists of an 

initial, screening-level tier that can be conducted quickly and efficiently to determine those 

facilities for which multipathway chronic risks are expected to be below levels of concern.

Regarding ground-level ozone, the language cited by the commenter was brief descriptive 

information in a memo on developments in technology in wood furniture manufacturing. As 

described in the preamble to the final rule, EPA conducted a risk assessment for HAP from the 

source category, including an analysis of multipathway and environmental effects, which is 

precisely what is required by section 112(f). EPA properly evaluated the risks from the HAP at 

issue from this source category.

17. Comment: Commenter 52 stated that EPA fails to provide a rational basis for using 

allowable emissions in conducting risk assessments under § 112(f). EPA uses the term ―MACT 

allowable‖ emissions in the preamble to mean ―the highest emission level that could be emitted 

by the facility without violating the MACT standards.‖ The Agency asserts that considering 

MACT allowable emissions in determining residual risk under § 112(f) ―is inherently reasonable 

since these risks reflect the maximum level sources could emit and still comply with national 

emission standards.‖ Without further explanation as to why it might be appropriate to determine 

and apply MACT allowable emissions in § 112(f) risk assessments, the Agency goes on to 

explain that it developed a ratio method of estimating MACT allowable emissions and ―applied 

these ratios on a facility-by-facility basis to the maximum chronic risk values from the inhalation 

risk assessment to obtain facility-specific maximum risk values based on MACT-allowable 

emissions.‖ The Agency considered risks based on MACT allowable emissions in its proposed 

risk assessments for the two subject source categories.

EPA cannot lawfully use MACT allowable emissions in the proposed risk assessments and 

residual risk determinations because the Agency has failed to provide any reasoned explanation 

for why risk assessments based on actual emissions estimates are inadequate. The Agency‘s risk 

assessment methodology already is rife with conservative assumptions. For example, health 

benchmarks, such as acute reference doses, typically incorporate two to three orders of 

magnitude of conservatism to account for uncertainties, such as the extrapolation of animal 

toxicity testing data to humans. Similarly, the dispersion models used to predict off-site ambient 

HAP concentrations attributable to emissions from affected sources incorporate numerous 

conservative assumptions to simplify the analysis of highly complex factors, such as 

meteorology and atmospheric chemistry. In addition, risk assessments assume exposure to the 

most exposed individual on a continuous basis for an entire lifetime. 

In light of the conservatism that already is inherent to EPA‘s risk assessment methodology, it 

makes no sense to apply yet another layer of conservatism – this time based on the hypothetical 

assumption that affected sources should be expected to emit more than the actual data indicate –

to § 112(f) risk assessments. EPA has provided no data or analyses indicating that its current 

methodology results in negative bias. EPA has provided no data demonstrating that affected 

sources actually do emit at levels significantly higher than the actual data show for any 
28

significant period of time. In short, EPA‘s proposal to use hypothetical emissions levels in § 

112(f) risk assessments is justified on nothing more than the bald assertion that sources might 

emit at these higher levels. The failure to provide a reasoned explanation as to why this approach 

is justified and the failure to provide any record evidence supporting the use of MACT allowable 

emissions render this proposal insupportable under the law.

Response: We have explained our use of both allowable and actual emissions in previous 

actions, including the final Coke Oven Batteries residual risk rule (70 FR 19998-19999, April 15, 

2005) and in the proposed and final SOCMI HON residual risk rules (71 FR 34428, June 14, 

2006, and 71 FR 76603, December 21, 2006, respectively). In those actions, we noted that 

modeling the allowable levels of emissions (i.e., the highest emission levels that could be emitted 

while still complying with the NESHAP requirements) is inherently reasonable since they reflect 

the maximum level sources could emit and still comply with national emission standards. But 

we also explained that it is reasonable to consider actual emissions, where such data are 

available, in both steps of the risk analysis, in accordance with the Benzene NESHAP. We also 

note that our use of allowable emissions levels in the risk assessments in this rulemaking did not 

result in revising the previously established standards based on risk concerns.

18. Comment: Commenter 45 pointed out that EPA‘s own data show greater reductions are 

being achieved and able to be achieved. EPA recognizes that certain sources have ―achieved‖ a 

level of ―actual‖ emissions that is below the level allowed under the existing MACT standards. 

EPA explains that ―the  ̳actual‘ emission levels are often lower than the emission levels that a 

facility might be allowed to emit and still comply with the MACT standards.‖ EPA‘s expectation 

that sources in these two categories are generally operating at half the level of emissions allowed 

under the existing MACT standard is at the core of its emission data analysis. Once EPA has this 

information, it must factor this into the technology review under section 112(d)(6). Doing so 

should lead EPA to revise the existing MACT for both source categories to require additional 

emission reductions.

As part of the required section 112(d)(6) rulemaking, EPA can have no possible justification for 

failing to recalculate the MACT floors based on new technology or emission reductions now 

achieved by these source categories.

The court in the HON decision stated that it did ―not think the words  ̳review, and revise

as necessary‘‖ required EPA to recalculate the floors ―from scratch‖ in that case. NRDC, 529

F.3d at 1084. In short, the NRDC Court expressly declined to decide whether EPA was required 

to recalculate floors where, as here, there have been developments in practices, processes, and 

control technologies.

As already noted above, for these source categories, there are such ―developments.‖

Therefore, EPA cannot rely on the HON case to evade its duty to satisfy section 112(d)(6). The

HON case did not authorize EPA to ignore data showing that significant emission reductions

below the ―MACT-allowable‖ emissions level have been ―achieved‖ in practice. Even under

NRDC – assuming arguendo that its section 112(d)(6) holding is in any way relevant here –

section 112(d)(6) requires EPA to recalculate the MACT floor when there have been advances in

technology (after taking account of the factors listed in section 112(d)(6)), and when there is
29

information showing that greater emission reductions are ―achieved in practice.‖ Commenters

contend that, based on the information EPA has, it is therefore ―necessary‖ for EPA to strengthen

the existing MACT floor to ensure it now complies with section 112(d)(2)-(3).

EPA must consider and address whether the existing MACT, including the floor, remains lawful 

in view of the greater levels of emission reductions that have been achieved.

Response: The commenter is mistaken on several grounds. First, the commenter asserts 

that ―the EPA recognizes that certain sources have  ̳achieved‘ a level of  ̳actual‘ emissions that is 

below the level allowed under the existing MACT standards‖ and cites the NPRM preamble at 

75 FR at 80227. This was a qualitative, introductory statement about how National Emissions 

Inventory (NEI) and other sources of data typically contain estimates of actual emissions that are 

―often‖ lower than allowable emissions. The statement was not specific to Wood Furniture or 

Shipbuilding facilities or data and in any event did not contain any quantitative determination 

about actual emissions levels.

Second, the commenter asserts that the EPA has an ―expectation‖ that wood furniture and 

shipbuilding sources are ―generally operating‖ at half of allowable emissions and once the EPA 

has this information, it must use it under CAA section 112(d)(6) to revise MACT standards, 

including recalculating MACT floors under section 112(d)(2)-(3). The comment apparently 

refers to the MACT allowable to actual emissions ratio developed for the source categories in 

this rulemaking. The commenter is incorrect in characterizing this ratio as a determination of the 

level of actual emissions achieved in practice in either source category. The actual to allowable 

ratio represents the lowest concentration of HAP in a coating available to the industry compared 

to the maximum allowed under the MACT. The allowable ratio is used for providing a worstcase scenario for estimating allowable emissions from the source. As clarification, for these 

coating rules, the concentrations of HAP in the coatings are considered the emissions from the 

source. 

Third, the commenter is incorrect in asserting that the EPA must recalculate MACT 

floors under CAA section 112(d)(2)-(3). As explained in prior RTR rulemakings, the EPA does 

not read 112(d)(6) as requiring a reanalysis or recalculation of MACT floors. See proposed 

National Emission Standards for Coke Oven Batteries (69 FR 48388, 48351 (August 9, 2004)). 

Instead, we interpret section 112(d)(6) as essentially requiring us to consider developments in 

pollution control in the industry (―taking into account developments in practices, processes, and 

control technologies‖), and assessing the costs of potentially stricter standards reflecting those 

developments. We read this provision as providing the EPA with substantial latitude in weighing 

these factors and arriving at an appropriate balance in considering revisions to our standards. 

This discretion also provides us with substantial flexibility in choosing how to apply modified 

standards, if necessary, to the affected industry.

The EPA reviewed other potential developments in practices, processes, and control 

technologies for the Wood Furniture Manufacturing Operations and Shipbuilding and Ship 

Repair (Surface Coating) source categories and evaluated costs of potentially more stringent 
30

standards reflecting any such developments.7EPA believes this review and the revisions 

finalized in this rulemaking satisfy the EPA‘s obligations under CAA 112(d)(6) for the Wood 

Furniture and Shipbuilding source categories.

19. Comment: For the residual risk review, commenter 45 stated that EPA should not rely on 

industry-reported, unverified emissions. EPA‘s Office of the Inspector General (OIG) has 

reviewed the NEI data and found problems with accuracy and significant data gaps, e.g., 57 

percent of the data points were blank, and unpopulated records represented about 39 percent of 

total point source emissions. The OIG further concluded that ―EPA‘s reliance on voluntary 

efforts to provide air toxics NEI data has not provided assurance that the data are accurate and 

reliable,‖ and recommended that EPA require reporting of data in order to gain the data needed 

to do an accurate residual risk assessment.

Commenter 45 also noted that the use of voluntarily reported emission data results in an 

underestimation of risk. EPA‘s proposal relies on the NEI, Toxics Release Inventory searches, 

and EPA‘s own estimate or modeling of missing data, based on default assumptions. The 

commenter encouraged EPA to make every effort in this and future rulemakings to use the 

section 114 information collection process and develop the best, most accurate dataset possible. 

Whenever voluntary reporting, estimates, emission factors, or assumptions are used to develop 

data, this creates room for serious underestimates of risk, whether due to human error or other 

problems.

According to the commenter these and other elements of uncertainty present in EPA‘s emissions 

dataset weigh in favor of taking a conservative, health-protective approach in the residual risk 

rulemaking process for each of these source categories.

Response: The emissions data for the two risk assessments in the proposed rules were 

derived from the National Emission Inventory (NEI) and directly from industry and states. The 

sources of the data are documented in the docket. More generally, we note that we have greatly 

improved the NEI for HAPs since the 1996 NEI, which was the basis for the IG Report referred 

to by the commenter. We have worked diligently with state and local agencies and tribes to 

improve emission inventories over the years and we have instituted a number of QA measures to 

improve data received from state and local agencies since 1996. The 2005 NEI underwent a 

number of QA steps that were not used in the 1996 NEI. Documentation for the 2005 NEI point 

source emissions inventory is available on EPA's CHIEF website, 

http://www.epa.gov/ttn/chief/net/2005inventory.html. Quality assurance and augmentation 

procedures used for the 2005 NEI point sources are contained in the report, EI Quality Assurance 

and Data Augmentation for Point Sources, posted at: 

 

7

 The EPA‘s review and analysis for the shipbuilding source category can be found in Affordability of Add-on 

Controls for Surface Coating Operations at Shipbuilding and Ship Repair Facilities, dated 10/28/2010, and for the 

wood furniture surface category in Affordability of Lower VHAP Coating and Add-on Controls for Wood Furniture 

Manufacturing Operations, dated October 28, 2010. Other significant memos describing the EPAs technology 

review are: 

Developments in Practices, Processes, and Control Technologies for Wood Furniture Manufacturing Operations, 

dated August 24, 2010; Impacts of Prohibiting the Use of Conventional Spray Guns in the Wood Furniture 

Manufacturing Operations Source Category, dated October 19, 2010; 

Cost Analyses for Control Options, dated September 27, 2010; Cost Analyses for Add-on Controls for Surface 

Coating Operations at Shipbuilding and Ship Repair Facilities, dated September 9, 2010.
31

http://www.epa.gov/ttn/chief/net/2002inventory.html. The 2005 NEI data have been reviewed 

extensively internally and externally during a 9 month effort as part of the development of the 

2005 National Air Toxics Assessment (NATA). As part of the 2005 NATA review, more than 

one million records for HAPs were revised. Updated test data and emission point information 

were received during the public comment period that addressed inaccuracies in the data.

For these source categories, EPA‘s review included an evaluation of facilities contained in the 

source category, the emissions units expected to be included for the processes in the source 

categories, coordinates and stack parameters and the HAP compounds and emissions levels 

typically seen. The EPA often had additional information on the source category, and where 

better data were available, this information was included in the proposal datasets. Sections 

V.A.1and V.B.1 of the December 21, 2010 proposal preamble (75FR80220) set forth a detailed 

explanation of the review that EPA performed on the emissions data for the source categories 

subject to this final rule.

In addition, as part of the December 21, 2010 proposal, we made the data sets available for 

review using a RTR data review tool in the docket and solicited comments on the data sets The 

RTR review of the proposal data sets act as another external third party review mechanism in 

addition to the external 2005 NATA review of the RTR data sets. Several opportunities have 

been provided to review the data used in the current proposal during the last 3 years. Through 

enhanced NEI QA procedures, 2005 NATA review, public comment on proposal files, source 

category-specific engineering reviews, and modeling, improvements to the data files have been 

made. We believe the data sets used in this rulemaking are sufficiently accurate and complete 

and constitute the best information EPA has concerning the emissions and risk from these source 

categories for conducting RTRs.

B. SSM PROVISIONS 

20. Comment: Commenter 52 disagreed with EPA‘s proposal to eliminate the SSM 

exemptions, arguing that EPA lacks authority, did not analyze why sources can be expected to 

meet the standards during SSM periods, and could have set separate standards for these periods. 

The proposal to eliminate the SSM provisions in the proposed rule is not based on an 

accurate reading of Sierra Club, is not supported by any rational explanation as to 

why the elimination of the SSM provisions is justified, and is arbitrary and capricious 

given that EPA fails to provide any analysis of why affected sources reasonably can 

be expected to meet the emissions limitations and standards that the Agency proposes 

to apply during periods of SSM. 

To begin, EPA‘s proposal ―that the standards in these rules apply at all times is not, 

as EPA claims, ―[c]onsistent with Sierra Club v. EPA.‖ The decision in that case was 

grounded in the court‘s assertion that § 112 requires emissions standards to apply at 

all times. Based on this, the court held the SSM General Provisions do not comport 

with § 112 because, in the eyes of the court, the SSM provisions are not ―section 112-

compliant‖ emissions standards. Notably, the court did not hold that EPA is 

prohibited from setting separate standards for periods of SSM. It simply held that 

standards for such periods must be developed according to the § 112(d) MACT 

process. 
32

EPA‘s flawed legal analysis provides no support for the proposal to eliminate the 

SSM provisions in the two subject rules. This fundamental legal flaw is magnified by 

the Agency‘s failure to provide any explanation whatsoever as to why it is 

appropriate to now apply the existing emissions standards to periods of SSM. For 

example, EPA made no effort to obtain emissions information from the two source 

categories for periods of SSM and provides no other evidence or analysis supporting 

its assertion that it is appropriate to apply the existing standards to periods of SSM. 

Moreover, EPA fails to investigate the record data developed during the promulgation 

of the existing standards to assess whether those data are characteristic and 

representative of emissions during periods of SSM. In short, the Agency simply 

asserts with no record basis that, ―because operations and emissions do not differ 

from normal operations during these periods, [the Agency] has not proposed different 

standards for these periods. This unsupported assertion provides no basis for 

extending the existing standards to periods of SSM. The failure to seek relevant data, 

assess existing data, and investigate whether the existing standards should 

appropriately apply to periods of SSM is facially arbitrary and capricious and 

provides no support for the Agency‘s proposal.

Commenter 41 stated that sources most likely cannot meet the MACT floor standards during 

SSM events:

EPA‘s statement that sources can meet the standards during SSM events is not based 

on any data. In fact it is most likely wrong. The current standards were developed 

during steady-state operations. It cannot reflect the variations that will be experienced 

during SSM events because no data was taken during these events. If EPA decides to 

require facilities to meet the same emission standards under both normal operations 

and during SSM events, they must use data gathered during both normal operations 

and SSM events in developing those standards. 

Typically, regulations require that a facility perform an initial test to show that they 

are in compliance with their current emission standards. EPA requires these tests to 

be run under steady-state conditions. In addition, this test is used to set operating 

parameters that the facility will show that it remains in compliance with the emission 

standards. EPA requires these tests to be run under steady-state conditions. In 

addition, this test is used to set operating parameters that the facility will show that it 

remains in compliance with the emission standards on a day-to-day basis. It is 

reasonable to use these operating parameters to show continued compliance during 

normal operations. However, conditions are constantly changing during SSM. The 

relationships developed during the initial test (and subsequent tests) between 

emissions and operating parameters are no longer valid under these conditions and 

cannot and should not be used to show compliance. To expect a facility to comply 

with the same operating limits during transient events would require extrapolation 

outside the range of the data used to develop the relationship. If a facility were to ask 

the Agency to be allowed to extrapolate an operating limit outside what was 

demonstrated during the test, it is likely that this request would be refused because 

there is no data to show that the relationship is still valid. The Agency could be 

correct in rejecting this request, depending upon the request. Yet, EPA is telling 
33

facilities to do just that during transient events-extrapolate beyond the range of the 

data used to develop the relationship. This is not scientifically correct nor is it 

appropriate.

Commenter 46 asserted that although the D.C. Circuit vacated the application of a ―general duty‖ 

to minimize emissions during SSM periods for standards promulgated under section 112 in the 

SSM Decision, it did so because it found that the general duty standard was not a ―Section 112-

compliant‖ standard. 551 F.3d at 1027-28. The D.C. Circuit found that EPA need not apply the 

same standard for normal operations during SSM periods and that EPA may justify the general 

duty standard for SSM periods under the alternative provisions of section 112(h). Id. EPA has 

not established that the standards that are now applicable to SSM periods are ―Section 112-

Compliant.‖ Section 112(d) requires a determination by EPA that the maximum degree of 

reduction required is ―achievable.‖42 U.S.C. §7412(d)(2). In setting the floors, the D.C. Circuit 

has affirmed EPA must look to what the best controlled unit ―achieved under the worst 

foreseeable circumstances.‖ Sierra Club v. EPA, 167 F.3d 658, 665 (D.C. Cir. 1999); see also 

Nat’l Lime Ass’n v. EPA, 233 F.3d 625, 631 (D.C. Cir. 2000). Thus, the Sierra Club decision 

does not require wholesale removal of the SSM exemptions.

The SSM Decision, however, does require EPA to ensure that the SSM standards are 

section 112-compliant. While EPA purports to carefully consider the provisions 

related to the SSM requirements, 75 Fed. Reg. at 80,226, 80,240, EPA wholly fails to 

carefully examine its new policy regarding SSM, which it does not support, with 

respect to the specific standards at issue here. In fact, EPA asserts that this rule 

―raises novel legal and policy issues,‖ 75 Fed. Reg. at 80,250, yet EPA does not 

address whether work practice standards are available in this case, or how its 

proposed revisions render the new SSM standards 112-compliant for these specific 

sources. Indeed, the discussion on EPA‘s rationale for its actions related to the SSM 

provisions mirrors that in an earlier proposed rule, wholly failing to recognize the 

distinctions between the analysis, content and form of the standards at issue here. 

Compare 75 Fed. Reg. at 65,074, with 75 Fed. Reg. at 80,225-80,226. The public 

cannot meaningfully comment without fully understanding the rationale behind 

EPA‘s actions or their impacts.

Moreover, EPA‘s actions are arbitrary and capricious because EPA failed to provide 

adequate support for its actions here and thus has not provided a ―reasonable‖ 

interpretation of section 112(d). It continues to fail to support its claims that 

―[p]eriods of startup, normal operations, and shutdown are all predictable and routine 

aspects of a source‘s operations,‖ and wholly fails to do so with respect to these 

source categories specifically. 75 Fed. Reg. at 80,225. It is likely that startup and 

shutdown operations differ among source categories, and there is no basis for such a 

generalized statement. For malfunctions, EPA simply asserts that it ―determined that 

malfunctions should not be viewed as a distinct operating mode, and, therefore, any 

emissions that occur during malfunctions do not need to be factored into development 

of CAA section 112(d) standards, which, once promulgated, apply at all times.‖ Id. 

Nowhere in the Clean Air Act is the term ―distinct operating mode‖ used. Rather, the 

D.C. Circuit has, as noted above, expressly found that EPA must consider emissions 

under the ―worst foreseeable conditions‖ and under ―recognized variations in 
34

operations.‖ Malfunctions fall under both these categories. Contrary to EPA‘s 

assertion, this does not require it to ―anticipate and account for the innumerable types 

of potential malfunction events in setting emission standards.‖Id. at 80,224-80,225. 

EPA need only provide a rationale basis for its determination. EPA cannot, however, 

simply ignore malfunctions in setting emissions standards.

Response: EPA notes as a preliminary matter that the comments concerning requirements 

applicable during startup and shutdown periods appear to be limited to facilities using a control 

device as a means of compliance to meet a numerical emission limit in the relevant NESHAP. 

As discussed in the Residual Risk Assessment for the Wood Furniture Manufacturing Source 

Category,8EPA believes that no more than 12 of 406 facilities subject to the Wood Furniture 

MACT use control systems for compliance with these standards. For Shipbuilding and Ship 

Repair facilities, we are only aware of the standard being met by the use of compliant coating. 

The overwhelming majority of facilities use compliant coatings, without a control device, to 

meet the standards. None of the comments raised startup, shutdown, or malfunction issues 

arising from use of compliant coatings without a control device or from complying with work 

practice requirements.

In Sierra Club v. EPA, 551 F.3d 1019 (D.C. Cir. 2008), the United States Court of Appeals 

for the District of Columbia Circuit vacated the startup, shutdown, and malfunction (SSM) 

exemption contained in section 63.6(f)(1) and (h)(1) of the part 63 General Provisions. The 

decision did not, as one commenter suggests, vacate the ―general duty‖ provision or determine 

that the general duty ―may‖ be justified as a 112(h) standard during SSM events. The court did 

note that EPA had not purported to act under section 112(h). The EPA agrees that we are not 

prohibited from setting separate standards for periods of startup and shutdown (see discussion 

below and response to comments section of the final rule for EPA‘s response on issues related to 

malfunctions). EPA is finalizing the removal of the startup and shutdown exemptions and is not 

promulgating separate emission standards for these source categories that apply during periods of 

startup and shutdown because EPA has no reason or data to support setting such separate 

standards. EPA did not propose separate emission standards for periods of startup and shutdown, 

because EPA had no data or other basis to set different standards for these periods. As discussed 

in the preamble to the proposed rule, EPA made available the facility-specific data used in the 

analyses for this rule and requested comments on the data, such as improvements and corrections 

to the datasets. The data elements for each facility specifically included fields for ―Startup 

Emissions,‖ ―Startup Emissions Max Hourly,‖ ―Shutdown Emissions,‖ and ―Shutdown 

Emissions Max Hourly.‖ EPA did not receive any such data from any commenter for periods of 

startup or shutdown at any facility in the database. Although certain commenters disagreed with 

EPA‘s proposed actions and criticized EPA‘s lack of data regarding startup and shutdown 

emissions, they did not submit any emissions or operational data regarding sources in either 

source category to support a different standard for periods of startup and shutdown.

EPA solicited comments from regulated sources and the public to inform our decision to 

remove the exemptions for periods of startup and shutdown. If EPA had received data in support 

of commenters‘ claims that compliance during startup and shutdown is impracticable, we could 

have assessed whether the data would cause us to reconsider our position and take steps to set 

 

8 Memorandum can be found in the docket for this rulemaking, EPA-HQ-OAR-2010-0786-0017.
35

different standards for periods of startup and shutdown. No such data was received for the 

source categories under consideration. 

Commenters‘ allegations that sources may not be able to meet the MACT standards during 

startup and shutdown are conclusory and lack supporting information or data. Based on 

information available to EPA, there are relatively few wood furniture facilities that use a control 

device to comply with the Wood Furniture NESHAP, and there is no reason to believe that 

processes at such facilities produce HAP emissions higher during startup or shutdown than 

during normal operations. To address the commenter‘s example, a wood furniture facility using 

a regenerative thermal oxidizer (RTO) as a control device to comply with the NESHAP can use 

solely natural gas as a fuel during startup and shutdown of the control device and send overspray 

stream to the control device only when the control unit is ready, e.g., performing at combustion 

temperatures. Under these conditions, facilities in the source categories in this rule should have 

no difficulty complying with applicable emission limits in the relevant NESHAP. EPA received 

no data or other information in public comments that contradicted these conclusions. 

 The commenter is correct that testing for emissions from a control device used as a 

means of compliance such as a regenerative thermal oxidizer (RTO) should be done during 

steady-state conditions, and periods of startup and shutdown generally do not qualify. In the case 

of spray lines controlled by an RTO, the spray is either on or off; so long as the spray is turned 

on only when the RTO is operating properly at combustion temperatures, EPA expects emissions 

will be much lower, not higher, during startup and shutdown than during steady-state conditions. 

Extrapolation is not necessary to show compliance during startup and shutdown because there is 

no transient period of emissions for these source categories. Provided that the control device is 

functioning properly prior to starting (and until completing) coating operations, and provided the 

control device has the necessary control efficiency, there is no reason to believe excess emissions 

will occur. For facilities that use RTOs as a means of compliance, the start-up and shutdown 

periods can be performed while running solely on an independent fuel source such as natural gas. 

Once the RTO reaches the proper operating temperature and is functioning properly, coating 

application may commence and over-spray can be routed to the RTO for destruction of HAP in 

compliance with the NESHAP. 

Thus, commenters have not identified any technical limitations or any other reason that 

startup or shutdown of the process or of a control device from a facility in the two source 

categories in this rule would cause a source to exceed an applicable emission limit.. In sum, 

while some commenters state that EPA lacks data to justify elimination of the exemption in the 

MACT standards for periods of startup and shutdown, as to sources relying on control devices 

for compliance, EPA believes there is a reasonable basis to eliminate the exemption and expect 

sources will not have difficulty complying with applicable MACT standards during startup and 

shutdown. Further, commenters have not identified any factual or legal basis to justify different 

standards during such periods. 

Periods of startup, normal operations, and shutdown are all predictable and routine aspects of a 

source‘s operations. However, by contrast, malfunction is defined as a ―sudden, infrequent, and 

not reasonably preventable failure of air pollution control and monitoring equipment, process 

equipment or a process to operate in a normal or usual manner * * * ‘‘(40 CFR 63.2). One 
36

commenter criticizes EPA for using the phrase ―distinct operating mode‖ in explaining its 

approach to malfunctions. EPA‘s choice of that phrase is not significant to its analysis. EPA has 

determined that CAA section 112 does not require that emissions that occur during periods of 

malfunction be factored into development of CAA section 112 standards. Under section 112, 

emissions standards for new sources must be no less stringent than the level ―achieved‖ by the 

best controlled similar source and for existing sources generally must be no less stringent than 

the average emission limitation ―achieved‖ by the best performing 12 percent of sources in the 

category. There is nothing in section 112 that directs the Agency to consider malfunctions in 

determining the level ―achieved‖ by the best performing or best controlled sources when setting 

emission standards. Moreover, while EPA accounts for variability in setting emissions 

standards consistent with the section 112 caselaw, nothing in that caselaw requires the Agency to 

consider malfunctions as part of that analysis. Section 112 uses the concept of ―best controlled‖ 

and ―best performing‖ unit in defining the level of stringency that section 112 performance 

standards must meet. Applying the concept of ―best controlled‖ or ―best performing‖ to a unit 

that is malfunctioning presents significant difficulties, as malfunctions are sudden and 

unexpected events. Further, accounting for malfunctions would be difficult, if not impossible, 

given the myriad different types of malfunctions that can occur across all sources in the category 

and given the difficulties associated with predicting or accounting for the frequency, degree, and 

duration of various malfunctions that might occur. As such, the performance of units that are 

malfunctioning is not ―reasonably‖ foreseeable. See, e.g., Sierra Club v EPA, 167 F. 3d 658, 662 

(D.C.Cir. 1999) (EPA typically has wide latitude in determining the extent of data-gathering 

necessary to solve a problem. We generally defer to an agency's decision to proceed on the basis 

of imperfect scientific information, rather than to "invest the resources to conduct the perfect 

study."). See also Weyerhaeuser v Costle, 590 F.2d 1011, 1058 (D.C. Cir. 1978) (― In the nature 

of things, no general limit, individual permit, or even any upset provision can anticipate all upset 

situations. After a certain point, the transgression of regulatory limits caused by  ̳uncontrollable 

acts of third parties,‘ such as strikes, sabotage, operator intoxication or insanity, and a variety of 

other eventualities, must be a matter for the administrative exercise of case-by-case enforcement 

discretion, not for specification in advance by regulation.‖). In addition, the goal of a best 

controlled or best performing source is to operate in such a way as to avoid malfunctions of the 

source and accounting for malfunctions could lead to standards that are significantly less 

stringent than levels that are achieved by a well-performing non-malfunctioning source. EPA‘s 

approach to malfunctions is consistent with section 112 and is a reasonable interpretation of the 

statute. 

21. Comment: Commenter 39 stated that the SSM changes are unreasonable and should be 

appealed.

[The commenter] relies upon control equipment to meet the emissions standards of 

the Subpart JJ MACT requirements at several sites. The control equipment provides 

the necessary emissions control and operational certainty where alternative materials 

are not practical or where they simply are not feasible. The SSM notice provided by 

EPA is in response to a court ruling that states (in part) conformance to the 40 CFR 

Part 63, Subpart A provisions for start-up, shut-down and malfunction of a control 

device cannot be relied upon as an affirmative defense in instances where the control 

devices has failed resulting in excess emissions. 
37

With any mechanical system, failures of the mechanical elements occur. Indeed, such 

devices must also be started up and shut down. Proper operation in accordance with 

and as detailed in the Subpart A requirements have been relied upon by those 

operations as reasonable for reducing overall emissions. Facilities operating in 

accordance with the SSM provisions have done so under the premise that those 

operating procedures are also reasonable for providing [an] operating safeguard for 

restricting excess emissions. 

Despite the added capital and operating expense to comply with the Subpart JJ 

provisions using control equipment, EPA has now made notice that ―playing by the 

rules‖ will not provide those same operations with assured compliance. This action 

adds unacceptable compliance risks that are unnecessarily burdensome. The change 

in SSM provisions has been superimposed upon operations that selected the control 

and HAP emissions reductions strategies years ago from a list of options designed by, 

promulgated by and sanctioned by U.S.EPA. 

Response: The EPA acknowledges that some facilities may use control devices to 

meet emission standards in Supbpart JJ. For the reasons explained above and in the 

response to comments section of the preamble to the final rule, EPA is removing the SSM 

exemption and has identified no technical or other reason not to do so. In addition, we are 

finalizing provisions for an affirmative defense, as discussed in the preamble.

22. Comment: Commenter 46 stated that EPA‘s Startup, Shutdown and Malfunction 

Provisions are arbitrary, capricious and otherwise not in accordance with law: 

Section 307(d) requires EPA to provide the public a meaningful opportunity to 

comment. 42 U.S.C. §7607(d)(3), (5); see also Kennecott Corp. v. EPA, 684 F.2d 

1007, 1018-19 (D.C. Cir. 1982). Part and parcel of this requirement is EPA‘s 

obligation to provide a statement of basis for its proposed Rule. 42 U.S.C. 

§7607(d)(3). The statement of basis must include: (a) the factual data on which the 

proposed Rule is based; (b) the methodology used in obtaining the data and in 

analyzing the data; and (c) the major legal interpretations and policy considerations 

underlying the proposed Rule. Id. EPA‘s only purported legal basis for these revisions 

is to make the SSM provisions ―[c]onsistent with Sierra Club v. EPA‖ (also referred 

to as ―SSM Decision‖). 75 Fed. Reg. at 80,225. EPA had identified Shipbuilding and 

Ship Repair as being directly affected by the SSM decision, because it incorporated 

by reference the vacated provisions, but not the Wood Furniture Manufacturing. 

Kushner Letter regarding Vacatur of SSM Exemption, July 22, 2009, available at 

http://www.epa.gov/compliance/civil/caa/ssm-memo080409.pdf (―Kushner Letter‖). 

Importantly, however, EPA fails to explain how application of the standards for 

normal operations to SSM, where it had previously been exempted, otherwise meets 

the requirements of section 112. In addition, EPA provides no factual support for its 

proposed changes or explanation as to why its proposed changes are necessary with 

respect to these specific source categories. As such, EPA‘s Proposed Rule fails to 

meet the procedural requirements of the Clean Air Act, and the public cannot 

meaningfully comment on the legal or factual bases for its proposed SSM provisions.
38

Response: EPA believes it provided a robust statement of basis for the proposed rule and 

satisfied all procedural requirements of the CAA. As to the SSM changes as they apply to Wood 

Furniture Manufacturing (Subpart JJ), the commenter notes the ―Kushner Letter‖ did not list 

Subpart JJ in attached tables of regulations that were believed to contain SSM exemption 

language. The purpose of the letter was to address potential compliance issues arising from the 

Sierra Club court decision and EPA‘s plan for addressing those concerns, including potential 

future revisions to section 112(d) standards. The letter at p. 3 expressly stated ―[t]he tables 

attached to this letter are based on EPA‘s initial analysis and are, therefore, subject to change‖ 

[footnote omitted].

In the proposed rule, EPA discussed the Sierra Club court decision, including the court‘s 

vacature of the SSM exemption in 40 CFR 63.6(f)(1). EPA proposed SSM changes, including a 

revision to Table 1 to Subpart JJ to specify that the SSM exemption in 40 CFR 63.6(f)(1), among 

other provisions, does not apply. Regardless of whether Subpart JJ was listed in the tables to the 

Kushner Letter, which were based on an initial analysis subject to change, EPA is finalizing the 

SSM changes, consistent with the basis and reasoning of the court‘s Sierra Club decision.

Regarding the application of standards to SSM periods, see EPA‘s responses above.

23. Comment: Commenter 45 stated that the affirmative defense is unlawful, would have 

harmful consequences for communities, will greatly reduce the deterrent impact of the standards, 

is outside of EPA‘s delegated authority by limiting civil penalties, will impermissibly chill 

citizen enforcement, undercuts Congress‘s intent that citizen enforcement should avoid redelving into technological or other considerations, and is equivalent to giving polluters a ―get out 

of jail free‖ card for serious violations:

An ―affirmative defense‖ for malfunctions...will reduce the deterrent value of the 

MACT standard and undermine or cut off the ability of people living near facilities 

that violate the standard to seek civil penalties.

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

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

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

enforcement mechanisms available to the government, and, in the HAP context, 

subject only to the limitation that government not be ―diligently prosecuting‖ its own 

civil enforcement action, CAA § 304(b)(1)(B), 42 U.S.C. § 7604(b)(1)(B). EPA‘s 

rule proposal, by shifting this careful balance and contravening these mandates, 

violates the CAA.

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

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

intent as to how judges should determine the size of civil penalties whenever they are 

sought and thus, under Chevron, U.S.A., Inc. v. Natural Res. Def. Council, Inc., 467 

U.S. 837, 842-43 (1984), flatly barred EPA from limiting when civil penalties can be 

assessed. In this proposal, EPA acts outside of its delegated authority to limit civil 

penalties available in citizen suits or its own enforcement actions. Second, the 

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

effective, deterrent remedy, in CAA enforcement.
39

The affirmative defense is fatally flawed because EPA cannot create a bright-line test 

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

limits that Congress intended to impose on citizens‘ ability to seek and recover 

penalties in enforcement suits under § 304. 42 U.S.C. § 7413(e). By attempting to 

impose additional agency-created limits, EPA exceeds its authority.

Congressional intent on civil penalties is clear—they are a remedy available to citizen 

plaintiffs, and judges have a list of factors to consider in assessing them. As such, 

EPA cannot interpret the statute to contravene that intent. By attempting to eliminate, 

via regulations, civil penalties in cases of malfunction where the violator 

demonstrates that certain factors [exist], EPA has done just that.

The CAA grants EPA minimal discretion that only applies to administrative penalties, 

allowing EPA to ―compromise, modify, or remit, with or without conditions, any 

administrative penalty which may be imposed under [subsection 113(d)].‖ 42 U.S.C. 

§ 7413(d)(2)(B).

However, there is no similar grant of authority to EPA to compromise, modify or 

limit civil penalties that a court may impose under section 113(e) or section 304. 

Section 304(a), 42 U.S.C. § 7604(a), grants courts the sole authority ―to apply 

appropriate civil penalties‖ in citizen suits. The explicit reference to EPA‘s ability to 

modify penalties in one subsection and its absence in the other subsection of the same 

provision can only be understood as an intentional decision by Congress that EPA 

cannot contravene by rule.

EPA‘s regulation would mean that if commenters or a local community group sued a 

shipbuilding or repair facility or a wood furniture manufacturing facility for its 

violation of the NESHAP, the owner would be exempt from paying civil penalties so 

long as the owner satisfied the requirements set forth in EPA‘s regulations. See 

Proposed Rule, 75 Fed. Reg. at 80,249 (to be codified at 40 C.F.R. §§ 63.781(d), 

63.800(j)). The owner would not be subject to civil penalties regardless how the 

congressionally mandated factors in the statute cut.54 That is, even if the owner 

benefited substantially from its violation, the penalty would not harm the owner 

economically, and the violation was extreme, the owner would not have to pay any 

civil penalty.

It is improper for a court to fail to consider the factors in CAA § 113(e)(1), or to fail 

to make its own determination of what civil penalties are ―appropriate‖ under CAA § 

304(a).55 A fortiori it is impermissible for EPA to attempt to displace those factors or 

in any way alter their significance by creating an absolute bar to penalties if certain 

agency-created considerations are met instead.

Citizen participation in CAA enforcement also will be hampered, in violation of 

citizens‘ rights to protect themselves from pollution and in direct conflict with 

congressional intent. The affirmative defense would likely be used on a routine basis 

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

result, citizens who seek civil penalties against polluters in order to protect 

themselves and achieve the Act‘s goals will be forced to engage in fact-intensive 

disputes over the cause of emission violations and adequacy of responsive measures –

an outcome Congress intended to prevent with the simple straightforward 
40

enforcement and penalty provisions in the Clean Air Act. As a result, enforcement of 

the Act will suffer, for civil penalties provide a powerful deterrent to violators as 

Congress intended. Thus, the affirmative defense also runs counter to two clearly 

expressed intentions of Congress: (1) the burden it places on citizens makes it less 

likely that they will enforce the Act, see, e.g., Pennsylvania v. Del. Valley Citizens’ 

Council for Clean Air, 478 U.S. 546, 560 (1986); and (2) several of the factors at 

issue in the affirmative defense undercut Congress‘s intent that citizen suit 

enforcement should avoid re-delving into ―technological or other considerations,‖ 

NRDC v. Train, 510 F.2d 692, 700 (D.C. Cir. 1974). Both result from the technical 

burden EPA imposes on citizens with the affirmative defense, and both render the 

defense impermissible.There is simply no need for an affirmative defense to penalties 

to be written into the regulations and cause the harm that will result. EPA has 

discretion to decide what cases to prosecute, to consider settlements, and to request 

civil penalties in a case-by-case manner, as long as it acts consistent with the Clean 

Air Act to protect clean air as its top priority, see 42 U.S.C. § 7401. Promulgating this 

affirmative defense is equivalent to giving polluters a ―get out of jail free‖ card for 

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

any violation of the standard is due to a malfunction in order to evade the 

requirements. Allowing polluters to evade financial penalties – which are the real 

teeth of the standards – through this type of measure is likely to lead to them simply 

ignoring or factoring potential standard violations into their cost of doing business, 

rather than actually trying to prevent malfunctions and violations of the standards as a 

way to avoid financial losses from the application of penalties.

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

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

provisions:

1. A specific amount of compensatory damages should apply to each reported 

malfunction. These funds should be dedicated to enforcement, inspections, 

and monitoring in the local community around the specific facility, to create 

greater assurance that malfunctions will not happen again.

2. EPA should modify the regulations so that the affirmative defense cannot be 

used by a specific facility or company more than once within a set period of 

time, such as 10 years. The affirmative defense should become automatically 

unavailable to a facility that has previously had a malfunction within the last 

10 years, to ensure that this defense does not swallow the value of the 

standards.

3. EPA should promulgate specific public reporting and notification 

requirements for malfunctions, or any emission exceedance that occurs of 

which an operator is aware. Specifically, EPA should require that when a 

facility provides EPA with a notification of a malfunction or emission 

standard exceedance under the regulations, this notice will be made publicly 

available on EPA‘s website within 14 days. In addition, EPA should 

promulgate the requirement that when such notification is made, the facility 

must also provide for community notification of the malfunction or emission 

standard exceedance within 2 business days, through an appropriate public 
41

forum that is designed to reach residents who live near the facility, including 

but not limited to a notice on the facility‘s own website (if it has one), a 

written notice to the local municipality and local school district, a press 

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

information community members may need to protect themselves and their 

families from the additional air pollution.

People living near the facilities in these source categories, and others regulated under 

section 112, are on the front lines in trying to protect themselves and their families 

from health problems due to air pollution that no one should have to worry about 

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

by Congress through an agency regulation sets a dangerous precedent. EPA should 

work to expand and protect the ability of people harmed by air pollution to seek all 

appropriate and available forms of relief in court. It should not retract or weaken 

citizen rights and remedies, as this proposal does, by making it more difficult for 

people to win meaningful relief from a facility that has released toxic air pollution 

into their community.

Response: EPA believes making available an affirmative defense to civil penalties for 

periods of malfunction is reasonable in light of the elimination of the malfunction exemption in 

the emission standards for these source categories. As discussed below, EPA believes this 

approach is consistent with the Clean Air Act and the Court's Sierra Club decision by 

eliminating the exemption for malfunctions while providing the opportunity for sources to avoid 

civil penalties by satisfying prescribed criteria. EPA does not expect the affirmative defense to 

affect significantly the practice of Clean Air Act enforcement, either by EPA or citizen suit. 

EPA has no reason to believe the affirmative defense to civil penalties will cause sources to 

violate emission standards.

EPA recognizes that even equipment that is properly designed and maintained can fail and that 

such failure can cause an exceedance of the relevant emission standard. EPA is providing an 

affirmative defense for the source categories in this rule in an attempt to balance a tension, 

inherent in many types of air regulation, to ensure adequate compliance while simultaneously 

recognizing that despite the most diligent of efforts, emission limits may be exceeded under 

circumstances beyond the control of the source. EPA must establish emission standards that 

―limit the quantity, rate, or concentration of emissions of air pollutants on a continuous basis.‖ 42 

U.S.C. § 7602(k) (defining ―emission limitation and emission standard‖). See generally Sierra 

Club v. EPA, 551 F.3d 1019, 1021 (D.C. Cir. 2008) ( emissions limitations under CAA section 

112 must both continuously apply and meet section 112‘s minimum stringency requirements, 

even during periods of startup, shutdown and malfunction). Thus, EPA is required to ensure that 

section 112 emissions limitations are continuous. The affirmative defense for malfunction 

events meets this requirement by ensuring that even where there is a malfunction, the emission 

limitation is still enforceable through injunctive relief. While ―continuous‖ limitations, on the 

one hand, are required, there is also caselaw indicating that in many situations it is appropriate 

for EPA to account for the practical realities of technology. For example, in Essex Chemical v. 

Ruckelshaus, 486 F.2d 427, 433 (D.C. Cir. 1973), the D.C. Circuit acknowledged that in setting 

standards under CAA section 111 ―variant provisions‖ such as provisions allowing for upsets 

during startup, shutdown and equipment malfunction ―appear necessary to preserve the 
42

reasonableness of the standards as a whole and that the record does not support the  ̳never to be 

exceeded‘ standard currently in force.‖ See also Portland Cement Association v. Ruckelshaus, 

486 F.2d 375 (D.C.Cir. 1973). Though intervening caselaw such as Sierra Club v. EPA and the 

CAA 1977 amendments undermine the relevance of these cases today, they support EPA‘s view 

that a system that incorporates some level of flexibility is reasonable. The affirmative defense 

simply provides for a defense to civil penalties for excess emissions that are proven to be beyond 

the control of the source. By incorporating an affirmative defense, EPA has formalized its 

approach to upset events. In a Clean Water Act setting, the Ninth Circuit required this type of 

formalized approach when regulating ―upsets beyond the control of the permit holder.‖ 

Marathon Oil Co. v. EPA, 564 F.2d 1253, 1272-73 (9th Cir. 1977). But see, Weyerhaeuser Co. v. 

Costle, 590 F.2d 1011, 1057-58 (D.C. Cir. 1978) (holding that an informal approach is 

adequate). The affirmative defense provisions give the EPA the flexibility to both ensure that its 

emission limitations are ―continuous‖ as required by 42 U.S.C. § 7602(k), and account for 

unplanned upsets and thus support the reasonableness of the standard as a whole.

Further, EPA‘s view is that the affirmative defense is not inconsistent with CAA section 113(e) 

or 304. Section 304 gives district courts jurisdiction ―to apply appropriate civil penalties.‖ 

Section 113(e)(1) identifies the factors that the Administrator or a court shall take into 

consideration in determining the amount of a penalty to be assessed, once it has been determined 

that a penalty is appropriate. The affirmative defense regulatory provision is not relevant to the 

amount of any penalty to be assessed. If a court determines that the affirmative defense elements 

have been established, then a penalty is not appropriate and penalty assessment pursuant to the 

section 113(e)(1) factors does not occur. 

In exercising its authority under section 112 to establish emission standards (at a level that meets 

the stringency requirements of section 112), EPA necessarily defines conduct that constitutes a 

violation. EPA‘s view is that the affirmative defense is part of the emission standard and defines 

two categories of violation. If there is a violation of the emission standard and the source 

demonstrates that all the elements of the affirmative defense are met, only injunctive relief is 

available. All other violations of the emission standard are subject to injunctive relief and 

penalties. The CAA does not require that all violations be treated equally. Further, a citizen 

suit claim under section 304 allows citizens to commence a civil action against any person 

alleged to be in violation of ―an emission standard or limitation under this chapter.‖ The CAA, 

however, allows EPA to establish such ―enforceable emission limitations.‖ Thus, the citizen suit 

provision clearly contemplates enforcement of the standards that are defined by EPA. As a 

result, where EPA defines its emissions limitations and enforcement measures to allow a source 

the opportunity to prove its entitlement to a lesser degree of violation (not subject to penalties) in 

narrow, specified circumstances, as EPA did here, penalties are not ―appropriate‖ under section 

304. 

EPA‘s view is that an affirmative defense to civil penalties for exceedances of applicable 

emission standards during periods of malfunction appropriately balances competing concerns. 

On the one hand, citizen enforcers are concerned about additional complications in their 

enforcement actions. On the other hand, industrial sources are concerned about being penalized 

for violations caused by malfunctions that could not have been prevented and were otherwise 

appropriately handled (as reflected in the affirmative defense criteria). EPA has utilized its 
43

section 301(a)(1) authority to issue regulations necessary to carry out the Act in a manner that 

appropriately balances these competing concerns.

The EPA disagrees that the affirmative defense provision will hamper citizen enforcement. First, 

injunctive relief is still available and the threat of penalties would not deter violations in cases 

where all of the conditions of the affirmative defense have been satisfied because the affirmative 

defense criteria ensure that all reasonable steps were taken to prevent a malfunction that causes 

excess emissions. Further, litigating whether a source has met the affirmative defense will not 

burden a citizen group any more or less than would litigating the appropriate penalty amount in 

the penalty assessment stage of a citizen suit enforcement action, because the section 113(e) 

penalty assessment criteria and the affirmative defense criteria are similar and in fact overlap. 

For example, the requirement that the Administrator or the court consider ―good faith efforts to 

comply‖ is bound to generate the type of fact-intensive disputes that the commenter complains 

of. In addition, several of the affirmative defense criteria are exactly the type of criteria the 

Administrator or Court might consider in determining whether a source made ―good faith efforts 

to comply.‖ For example, to take advantage of the affirmative defense, the source must prove by 

a preponderance of the evidence that, among other things, the excess emissions ―were caused by 

an unavoidable failure of air pollution control and monitoring equipment, process equipment, or 

a process to operate in a normal or usual manner‖ and ―could not have been prevented through 

careful planning, proper design or better operation and maintenance practices‖ and ―did not stem 

from any activity or event that could have been foreseen and avoided, or planned for.‖ 

Thus, the EPA does not expect the affirmative defense provision to significantly alter the burden 

of bringing a citizen enforcement action. For those cases that do proceed to trial, even in the 

absence of this affirmative defense, sources generally raise equitable arguments to argue for a 

low penalty and citizens often rebut such arguments. Therefore, as a practical matter, the EPA 

does not expect the affirmative defense provision to materially affect the practice of CAA 

enforcement.

Additionally, the affirmative defense is reasonable. The EPA‘s judgment is that the affirmative 

defense criteria capture the appropriate considerations in determining whether penalties are 

appropriate when a violation occurs as the result of a malfunction. As noted above, the 

affirmative defense criteria overlap to some extent with the penalty assessment criteria set forth 

in section 113(e), but are not identical. For example, size of business is one of the factors listed 

in section 113(e), but is not reflected in EPA‘s affirmative defense. This reflects the EPA‘s view 

that when a violation is caused by a malfunction, the size of the business is not relevant to 

whether penalties should be excused. If the violation was unavoidable and could not have been 

prevented, the EPA‘s view is that it would be unfair to impose a penalty no matter the size of the 

business. 

Contrary to assertions in some comments, sources will not be able to ―simply ignor[e] or factor[] 

potential standard violations into their cost of doing business, rather than actually trying to 

prevent malfunctions and violations‖. The affirmative defense provision provides that the 

defendant must prove the excess emissions were, inter alia, unavoidable, could not have been 

prevented through careful planning, proper design or better operation and maintenance practices, 

did not stem from any activity or event that could have been foreseen and avoided, or planned 
44

for, and were not part of a recurring pattern indicative of inadequate design, operation, or 

maintenance. 40 CFR 63.781(d)(1) & 63.800(j)(1).EPA is not adopting commenters‘ suggestion 

with respect to compensatory damages or limits on the frequency of use of the affirmative 

defense. It is not clear that EPA has authority to require the automatic imposition of 

compensatory damages and even if such authority exists, EPA does not think automatic 

imposition of damages is appropriate. Ensuring that malfunctions do not recur can be handled 

through imposition of appropriate injunctive relief. In addition, EPA‘s view is that it would not 

be appropriate to limit a source‘s ability to take advantage of the affirmative defense to one time 

over a specified period of time such as ten years given that the affirmative defense is only 

available when the source could not have prevented the excess emissions. With respect to 

commenters‘ suggested reporting requirements, the reporting requirements in the rules 

promulgated today already require malfunction reporting and the affirmative defense provisions 

require that parties choosing to assert the affirmative defense meet additional malfunction 

reporting requirements. Any such reports submitted to EPA are publicly available pursuant to 

CAA section 114.

24. Comment: Commenter 41 believes that although EPA must take into account SSM events 

in establishing limits, the commenter agrees that a regulatory provision containing some form of 

enforcement discretion such as an affirmative defense is needed for malfunctions. The 

commenter expressed concern about the burden of proof and suggested EPA establish a 

rebuttable presumption (rather than affirmative defense) where it is presumed that the facility did 

everything in their power to minimize emissions during these events, unless the Agency proves 

certain facts that are enumerated in the rules. If the Agency wants to challenge these activities, 

the burden of proof would be on them to show that the facility did not undertake reasonable 

actions to minimize emissions. The commenter also recommended the following:

1. Define ambiguous terms such as ―careful‖, ―proper‖, and ―better‖;

2. Delete reference to ―any‖ activity;

3. Delete references to ―all‖ activities.

Commenter 46 states that to the extent EPA cannot set an achievable emissions limit or work 

practice standard for SSM events, e.g., because it may not be possible to identify every type of 

malfunction in setting emission standards, the commenter did not dispute EPA‘s authority to 

provide an affirmative defense. The commenter says EPA did not explain why the affirmative 

defense does not apply to periods of startup and shutdown. The commenter stated that EPA has 

clear authority to provide an affirmative defense for malfunctions and that EPA has recognized 

the need to consider ―upsets‖ when establishing technology-based standards under the Clean 

Water Act, citing: CMA v. EPA, 870 F.2d 177, 228-30 (5th Cir. 1989); Weyerhauser v. Costle, 

590 F.2d 1011, 1057 (D.C. Cir. 1978); FMC Corp. v. Train, 539 F.2d 973, 986 (4th Cir. 1986); as 

well as certain aspects of a 1999 EPA Memorandum on SIPs and SSM emissions. The 

commenter supported the incorporation of the definition of ―malfunction‖ in 40 C.F.R. §63.2 and 

stated that a regulated entity should be able to assert a malfunction has occurred as an affirmative 

defense. The commenter objected to the proposed criteria for an affirmative defense and 

recommended changes:
45

EPA asserts that the proposed criteria seek to ―ensure that the affirmative defense is 

available only where the event that causes an exceedance of the emission limit meets 

the narrow definition of malfunction in 40 C.F.R. §63.2.‖ 75 Fed. Reg. at 80,226 

(emphasis added). The criteria outlined in the Proposed Rule to establish the 

affirmative defense, however, are inconsistent with this definition and must be 

eliminated. There simply is no justification to include criteria to establish an 

affirmative defense against an alleged violation that are more onerous than the 

requirements of the regulations. 

Other criteria require ―all possible steps,‖ actions ―if at all possible‖ and repairs ―as 

expeditiously as possible.‖ Proposed 40 C.F.R. §§63.781(d)(1), 63.800(j)(1). These 

criteria are substantially more restrictive than the requirements to show a malfunction 

under the definition, and these more restrictive criteria would result in only a subset 

of malfunctions being considered eligible for the affirmative defense, if any at all, 

undermining the purpose of the provision.

Other criteria are more stringent than, or at least redundant of, the general duty 

standard and, again, should be eliminated. For example, the third criteria requires a 

showing that the ―frequency, amount, and duration of the excess emissions (including 

any bypass) were minimized to the maximum extent practicable during periods of 

such emissions‖ while the eighth criteria requires a showing that ―the facility was 

operated in a manner consistent with good practices for minimizing emissions.‖ 

Proposed 40 C.F.R. §§63.781(d)(1), 63.800(j)(1). The general duty requires each 

owner or operator to operate and maintain any affected source ―in a manner 

consistent with safety and good air pollution control practices for minimizing 

emissions.‖ The listed criteria for establishing an affirmative defense may impose a 

greater burden on regulated entities than would otherwise be required by the 

standards. At a minimum, they are redundant of the general duty standard and may 

cause undue confusion as to the applicable requirements.

EPA provides no explanation for using these onerous criteria. Although EPA cites to 

two memoranda addressing EPA‘s policy on how State Implementation Plans should 

treat excess emissions during SSM, 75 Fed. Reg. at 80,226, these memoranda are 

inapplicable to technology based standards. See EPA Mem., State Implementation 

Plans: Policy Regarding Excessive Emissions During Malfunctions, Startup, and 

Shutdown, at n.6 (Sept. 20, 1999). For technology-based standards, EPA and courts 

have recognized that EPA must either (a) consider SSM in setting the standards or (b) 

provide an upset defense. Moreover, EPA provides no comparison as to the greater 

stringency of the affirmative defense as applied to malfunctions compared to the 

requirements for malfunction currently imposed under these source categories, 

particularly for Wood Furniture Manufacturing. EPA is, again, trying to impose a 

one-size-fits-all approach to these standards without providing any support, failing to 

give the public a meaningful opportunity to comment and rendering EPA‘s actions 

arbitrary and capricious. 

Further, EPA provides no explanation as to why it has chosen to move away from the 

long-standing upset defense at 40 C.F.R. §122.41(n), promulgated under the Clean 

Water Act. Under that provision, an ―upset constitutes an affirmative defense.‖ 40 

C.F.R. §122.41(n)(2). To establish the defense, the following criteria must be met:
46

an upset occurred and the permittee can identify the cause(s) of the upset;

the permitted facility was at the time being properly operated;

the permittee submitted notice of the upset (required within 24 hours).

the permittee took all reasonable steps to minimize or prevent the violation.

The criteria outlined in the Proposed Rule are significantly more stringent than those 

provided in the Clean Water Act‘s ―upset defense,‖ imposing substantial burdens on 

regulated entities for actions that, by definition, are not the fault of the facility.

Thus, EPA must reconsider its SSM provisions, and reissue a proposal that provides 

its full legal and factual support for its determinations as to the appropriate standard 

to apply to SSM periods. If EPA subsequently determines to utilize an affirmative 

defense, then it should eliminate the criteria in the proposal, and require the regulated 

entity to establish a malfunction, as defined in section 63.2 occurred. Alternatively, 

we suggest using the Clean Water Act‘s upset defense as a model, rather than the 

1983 and 1999 EPA memoranda on excess emissions that do not adequately address 

the treatment of SSM events in technology-based standards.

Response: EPA is promulgating the affirmative defense for malfunctions only, not for 

periods of startup and shutdown. As explained above, EPA believes that malfunction events 

should be treated differently than periods of startup and shutdown, which are predictable and 

routine aspects of a source ̳s operations. Further, periods of startup and shutdown – but not 

malfunctions -- are taken into account when establishing section 112 emissions standards. For 

these reasons, EPA does not believe it is appropriate to apply the affirmative defense provision to 

startup and shutdown periods.

Many of the conditions in the affirmative defense are modeled after the affirmative defense 

in EPA‘s SIP SSM policy, See, e.g., State Implementation Plans: Policy Regarding Excessive 

Emissions During Malfunctions, Startup, and Shutdown (Sept. 20, 1999); Other conditions are 

modeled after a Federal Implementation Plan promulgated by EPA. (40 C.F.R. 50.1312). EPA‘s 

view is that use of consistent terms in establishing affirmative defense regulations and policies 

across various CAA programs will promote consistent implementation of those rules and 

policies. Although, as commenter notes, the SIP policy does not apply to technology-based 

standards because the expectation was that technology-based standards would contain provisions 

that already account for technological limitations, nothing in the policy addresses the form that 

such provisions in technology-based standards should take. As explained above, EPA has 

determined that including affirmative defense provisions in such standards is appropriate and 

reasonable. The commenters do not explain their view that the terms of the SIP policy are not 

appropriate to address malfunctions in the CAA section 112 context. The affirmative defense 

does not require a facility to prove its innocence rather than requiring an enforcement authority 

to prove a violation of the CAA or change the burden of proof with respect to establishing a 

violation. The affirmative defense applies only where a violation has been established. The 

burden of proof that a violation occurred remains with the plaintiff in an enforcement action. 

See, e.g., 40 C.F.R. 22.24. If a violation has been established and a source wishes to assert the 

affirmative defense with respect to penalties, the source does bear the burden of establishing that 

the elements of the affirmative defense have been met. This burden-shifting is appropriate 

because the source is in a better position to determine the facts required to establish the defense. 
47

See, e.g., Arizona Pub. Serv. Co. v. EPA, 562 F.3d 1116, 1120, 1129-30 (10th Cir. 2009) 

(rejecting industry challenge to EPA‘s use of an affirmative defense to address excess emissions 

during malfunction events.). The notification and reporting requirements are not unreasonable 

and are consistent with other malfunction reporting and notification requirements that have been 

applied without significant difficulty. (See, e.g., 40 CFR 63.6(e)(3)(iv) and 63.10(d)(5)(ii)). 

Section 114 of the CAA clearly provides authority to require such reports. 

EPA believes the affirmative defense criteria are well-defined and will assist EPA and the 

courts in making reasoned determinations as to the establishment of affirmative defenses. EPA 

and the courts have expertise and experience in evaluating and applying criteria such as those for 

the affirmative defense. As noted above, many of the conditions were modeled after the 

conditions of the affirmative defense in EPA‘s SIP SSM policy, which several states have 

adopted into their SIPs. We do not have any indication that parties to enforcement proceedings 

have had any significant difficulties applying the terms of these SIP affirmative defenses. 

However, EPA believes that some of the terms or phrases in the regulatory text establishing the 

affirmative can be revised or streamlined to some extent. EPA is revising the affirmative defense 

language to delete ―short‖ from the affirmative defense provisions, because other criteria in the 

affirmative defense require that the source assure that the duration of the excess emissions was 

―minimized to the maximum extent practicable.‖ In addition, EPA is adding the phrases 

―consistent with good air pollution control practice for minimizing emissions‖ to 

63.781(d)(1)(viii) and 63.800(j)(1)(viii). We are also deleting the term ―severe‖ in the phrase 

―severe personal injury‖ because we do not think it is appropriate to make the affirmative 

defense available only when bypass was unavoidable to prevent severe personal injury. We have 

revised several phrases in the affirmative defense provisions to refer to the ―affected source‖ 

which is defined in §63.2. EPA does not believe that other terms and conditions of the 

affirmative defense are overly subjective or extreme or need further qualification. EPA 

acknowledges that some of the criteria may overlap to some extent and under some 

circumstances, but does not believe it is necessary to change the requirements. To the extent 

there is overlap, the same information can be used to meet the provisions in question. EPA is not 

eliminating the word ―infrequent‖ from the affirmative defense provisions, because that term 

appears in the definition of malfunction in 63.2. 

With respect to comments that the affirmative defense should be stated instead in terms 

such as a rebuttable presumption so that, once a source has claimed that its excess emissions 

were related to a malfunction, it will not be considered to be in violation of the standards unless 

the enforcement authority demonstrates that the source is not entitled to claim the malfunction, 

or has not taken reasonable actions to minimize emissions, EPA does not agree that the 

affirmative defense should operate as suggested. The comment improperly seeks to shift the 

burden of proof from the source to EPA. It is the source, not EPA that has the information 

relevant to assess whether a particular event qualifies as a malfunction and meets the affirmative 

defense. Furthermore, the suggested approach appears to be similar to the scheme that the court 

vacated in the Sierra Club case, in that there would be no violation unless the enforcing party 

(EPA or a citizen), established that the event in question was not a malfunction. 

With respect to the comment concerning operating logs, EPA believes that log entries 

should be made contemporaneously, which does not mean, at the exact time that the engineers 

are taking actions to address the malfunction, but rather immediately thereafter. That way, more 
48

accurate records of the malfunction can be expected, as opposed to records reconstructed long 

after the malfunction.

25. Comment: Commenter 41 noted that the requirement to do a root cause analysis jumps to 

the final step without considering that there may be many steps in determining causality:

For many malfunctions, the cause is immediately obvious. When a malfunction 

occurs, the expectation is that the facility will correct the problem as quickly as 

possible and return to their operating window. A root cause analysis is typically 

limited to very significant events or repeat events. The proposed language assumes 

that all malfunctions are equally significant and need an identical degree of 

investigation. For example, a root cause analysis should only be used as a last resort 

when other reasonable methods fail to show what caused the malfunction or when the 

serious nature of an event might make such an analysis necessary. Moreover, other 

tools may be more appropriate (e.g. failure mode and effect, fault tree, etc.) or more 

powerful tools may be introduced in the future. The facility is the only one that can 

and should decide what tool to use to determine the cause of the malfunction. If it is 

necessary to do a root cause analysis (or some other detailed analysis), it may not be 

possible for that to be completed in 30 days. It is reasonable to develop a report of the 

cause and whatever corrective action was taken within 30 days if that cause was 

simple. However, if the event was significant and a more detailed analysis was 

required, a facility would need more time (e.g. 90 days) to complete that report. It 

should also be noted that it is impossible to eliminate the causes for certain 

malfunctions (e.g. Lightning strikes). Finally, faxing is an obsolete technology. EPA 

should allow notification by e-mail or other electronic forms.

Response: EPA is revising the root cause analysis requirement to clarify that the purpose 

of the root cause analysis is to determine, correct, and eliminate the primary cause of the 

malfunction and that the root cause analysis itself does not necessarily require that the cause be 

determined, corrected or eliminated. However, in most cases, EPA believes that a properly 

conducted root cause analysis will have such results. EPA does not assume that all malfunctions 

require an identical degree of investigation. EPA expects that the effort required to do a root 

cause analysis will vary depending on the nature of the malfunction. EPA is also revising this 

requirement to state that a written report must be submitted within 45 days of the initial 

occurrence of the malfunction. We further revised this provision to allow the source to seek an 

extension of up to an additional 30 days. 

EPA generally accepts documents in electronic format, as long as the format is compatible with 

the requirements of the standards. For the affirmative defense provisions, the owner or operator 

of a facility experiencing an exceedance of its emission limit(s) during a malfunction must notify 

the Administrator by telephone or facsimile (FAX) transmission of the exceedance. However, 

the written reports required to demonstrate that the affirmative defense provisions have been met 

and requests for an extension of the deadline for these reports may be submitted electronically. 

26. Comment: Commenter 46 further stated that an affirmative defense is insufficient to 

absolve EPA of its duty to set Section 112-Compliant Standards: 
49

EPA has consistently recognized that malfunctions are inevitable. As such, EPA must 

account for emissions associated with malfunctions in setting the applicable standard. 

―A technology-based standard discards its fundamental premise when it ignores the 

limits inherent in the technology.‖ NRDC, 859 F.2d at 208. Failing to account for 

these inevitable failures would ―in effect hol[d] dischargers to a higher standard of 

technology than that demanded by the Act.‖ Id. at 207; see also Cement Kiln 

Recycling Coalition v. EPA, 255 F.3d 855, 872 (D.C. Cir. 2001) (noting doubts of 

legality of technology-based standards that would require ―sources to comply with 

standards even during openings of emergency safety valves caused by events beyond 

the sources‘ control‖). Rather than attempt to promulgate section 112-compliant 

standards, as described above, EPA proposes to establish an ―affirmative defense‖ for 

malfunctions only. This ―affirmative defense‖ is wholly insufficient to meet EPA‘s 

obligations under section 112. 

Response: The affirmative defense is not intended as a substitute for standards under 

section 112. EPA has determined that CAA section 112 does not require that emissions that 

occur during periods of malfunction be factored into development of CAA section 112 standards. 

Under CAA section 112, emissions standards for new sources must be no less stringent than the 

level ―achieved‖ by the best controlled similar source, and for existing sources, generally, must 

be no less stringent than the average emission limitation ―achieved‖ by the best performing 12 

percent of sources in the category. There is nothing in CAA section 112 that directs the Agency 

to consider malfunctions in determining the level ―achieved‖ by the best performing or best 

controlled sources when setting emission standards. Moreover, while EPA accounts for 

variability in setting emissions standards consistent with the CAA section 112 case law, nothing 

in that case law requires the Agency to consider malfunctions as part of that analysis.

CAA section 112 uses the concept of ―best controlled‖ and ―best performing‖ unit in 

defining the level of stringency that CAA section 112 performance standards must meet. 

Applying the concept of ―best controlled‖ or ―best performing‖ to a unit that is malfunctioning 

presents significant difficulties, as malfunctions are sudden and unexpected events. Accounting 

for malfunctions would be difficult, if not impossible, given the myriad different types of 

malfunctions that can occur across all sources in the category, and given the difficulties 

associated with predicting or accounting for the frequency, degree, and duration of various 

malfunctions that might occur. As such, the performance of units that are malfunctioning is not 

―reasonably‖ foreseeable. See, e.g., Sierra Club v. EPA, 167 F. 3d 658, 662 (D.C. Cir. 1999) 

(EPA typically has wide latitude in determining the extent of data-gathering necessary to solve a 

problem. We generally defer to an agency's decision to proceed on the basis of imperfect 

scientific information, rather than to "invest the resources to conduct the perfect study."). See 

also, Weyerhaeuser v. Costle, 590 F.2d 1011, 1058 (D.C. Cir. 1978) (―In the nature of things, no 

general limit, individual permit, or even any upset provision can anticipate all upset situations. 

After a certain point, the transgression of regulatory limits caused by  ̳uncontrollable acts of third 

parties,‘ such as strikes, sabotage, operator intoxication or insanity, and a variety of other 

eventualities, must be a matter for the administrative exercise of case-by-case enforcement 

discretion, not for specification in advance by regulation.‖). In addition, the goal of a best 

controlled or best performing source is to operate in such a way as to avoid malfunctions of the 

source, and accounting for malfunctions could lead to standards that are significantly less 
50

stringent than levels that are achieved by a well-performing non-malfunctioning source. EPA‘s 

approach to malfunctions is consistent with CAA section 112, and is a reasonable interpretation 

of the statute. 

Further, the NRDC case cited by the commenter interprets provisions of the Clean Water Act 

that are different in nature than provisions governing standards under section 112 of the Clean 

Air Act and the discussion of technology-based standards is dicta. Nevertheless, EPA ̳s approach 

to malfunctions is consistent with NRDC and the cases cited therein; Marathon Oil Co. v. EPA, 

564 F.2d 1253, 1272 (9th Cir. 1977). The court in Marathon Oil held that EPA must formalize 

its approach to upsets under the Clean Water Act and the affirmative defense does so. But see, 

Weyerhaeuser v Costle, 590 F.2d 1011, 1057-58 (D.C. Cir. 1978) (holding that an informal 

approach is adequate).

C. ENVIRONMENTAL JUSTICE 

27. Comment: Commenter 42 commended EPA for considering environmental justice issues 

by expressing concern about the disproportionate impacts of the HAP emissions on certain 

social, demographic, and economic groups. However, the commenter recommended some 

improvements:

As stated in EPA‘s ―Interim Guidance on Considering Environmental Justice During 

the Development of an Action,‖ the agency should consider addressing existing 

disproportionate impacts on minority, low-income or indigenous populations during 

rulemaking. [The commenter] recommends EPA conduct a full evaluation of 

disproportionate impacts following the guidance in EJSEAT and an evaluation of 

how this risk assessment could reduce impacts to those communities. EPA‘s Online 

Tracking Information System database appears to do this already at the facilityspecific level and can be incorporated into the assessment to more accurately define 

the number of the individuals impacted by the emissions and the demographics of the 

impacted community. Additionally, we recommend the rule writers work with the 

EPA Office of Environmental Justice to adequately evaluate the proposed rulemaking 

with regard to communities experiencing disproportionate impacts. 

Response: The demographic assessments for both source categories contain information 

on the cancer risk from the facility-wide HAP emissions as well as the cancer risk from the 

source category-specific HAP emissions. While these figures do not capture total risk, they 

provide estimates of the existing distribution of cancer risks across population groups, which is 

the health outcome of most concern related to the facilities and pollutants being regulated. 

While the EJSEAT and OTIS database are general tools that can be used in considering 

environmental justice issues, the demographic analyses we performed is superior for purposes of 

this rulemaking because they are more specific to these particular source categories. We note that 

we are working with the Office of Environmental Justice in an ongoing effort to develop new 

tools for considering environmental justice in rulemakings. We also note that our ability to 

quantitatively assess EJ issues is evolving; over time we expect it to become more robust, 

sophisticated, and capable of ensuring that we are meeting our mission as an agency.
51

28. Comment: Commenter 46 stated EPA should consider the potential repercussions to 

communities of the potential loss of industry when taking into account EJ issues.

If EPA requires more stringent controls for a particular source category as a result of 

a demographic analysis, all sources in the source category, regardless of location may 

be forced to assume the additional costs and burdens unless the Agency is willing to 

discriminate among sources within a category. This means that many sources would 

be required to install additional controls even though the population surrounding the 

source is not at an increased risk (unless EPA is willing to depart from this longstanding approach to regulation under section 112).

In setting standards based on classifications related to EJ concerns, EPA will put 

existing and new businesses on notice that they must expect more stringent controls if 

they plan to continue to operate within these areas. Many businesses may decide to 

move away from areas so designated by EPA to avoid more stringent controls. This in

turn would reduce economic activity in the area and employment, potentially making 

the areas economically disadvantaged. While EPA‘s intentions may be laudable, the 

communities themselves may find the repercussions to be more health threatening 

than the added protections afforded by the pollution controls, especially if it results in 

greater unemployment and reduced income. EPA should consider these impacts of 

regulation on these communities as part of its EJ review. EPA should set a high bar 

for distinguishing sources, and imposing separate standards, based on potential EJ 

concerns, and that such standards should reflect a clear need for further protection of 

public health concerns.

Response: Potential impacts on the regulated industry and on employment are accounted 

for in the Regulatory Impact Analysis, which uses a standard method for estimating these 

impacts. These impacts, along with potential environmental and health impacts, inform the 

Agency‘s rulemaking decisions to the extent consistent with the Clean Air Act. In the 

rulemakings for these two source categories, EPA has not established any different control 

requirements based on the demographic analyses it performed.

29. Comment: Commenter 52 objected to consideration of demographic analyses under 

section 112(f). The commenter noted that although EPA conducted an ―environmental justice‖ 

assessment for the two rules covered by the proposal, EPA determined that those analyses did 

not provide a basis for imposing additional control measures in order to assure an ample margin 

of safety.

Because the term ―public health‖ cannot reasonably be interpreted to include 

consideration of environmental justice in the § 112 context, EPA proposal to consider 

demographic analyses in conducting risk reviews under § 112(f) is not a proper 

exercise of Agency authority.

EPA‘s proposal would unreasonably inject racial, ethnic, and other policy 

considerations into a program designed to provide protection for the public at large. 

For example, EPA suggests that the population without a high school diploma should 

receive extra scrutiny, yet does not afford the same scrutiny to other reasonably 

definable educational groups, such as those with a high school diploma, those with 
52

college degrees, and those with advanced degrees. There is simply no principled way 

to identify and define those groups that should receive extra scrutiny from those that 

do not. In short, EPA‘s approach would inappropriately cause arbitrary policy and 

political considerations to trump objective scientific analysis. This is patently 

unreasonable and, as such, is not a supportable interpretation of § 112(f).

Response: In this rulemaking, EPA developed demographic analyses as part of the risk 

assessment for each source category; the analyses did not change the results or conclusions in the 

assessments. See also Comment above concerning Facility-wide risk and demographic analyses 

and Response thereto. As stated in the Benzene NESHAP, in determining the need for residual 

risk standards, we strive to limit to no higher than approximately 1-in-10 thousand (100 in a 

million) the estimated cancer risk that a person living near a plant would have if he or she were 

exposed to the maximum pollutant concentrations for 70 years and, in the ample of safety 

decision, to protect the greatest number of persons possible to an individual lifetime risk level of 

no higher than approximately 1-in-1 million. These considerations are made for all people 

regardless of racial or socioeconomic status. However, in determining whether to require 

additional standards under § 112(f), these levels are not considered rigid lines, and we weigh the 

cancer risk values with a series of other health measures and factors in both the decision 

regarding risk acceptability and in the ample margin of safety determination. We also consider 

cost of controls in the ample margin of safety determination. While we analyzed the

demographic makeup of the at-risk populations surrounding the facilities within source

categories addressed by this rule making, we ultimately concluded that the risks from each

source category were acceptable and protected public health with an ample margin of safety. 

Thus, the results of our demographic analyses only served to provide information about the 

demographic makeup of the populations exposed to each of these source categories.

II. WOOD FURNITURE

A. RISK ASSESSMENT

30. Comment: Commenter 49 stated that Legacy Cabinets is now importing finished cabinets 

from China and shut down one of two finishing lines because of the economy. Please note 

Legacy Cabinets is one of the 11 facilities with formaldehyde emissions that could result in 

exceedances of the acute REL.

Commenter 40 provided improved facility data. Below is a summary of the corrected data:

Table 1. Commenter 40 Data Summary

Total NC 

facilities 

identified by 

EPA

No changes 

needed

Facility name 

or address 

update

Facility 

emissions or 

process 

update

Name/ 

address and 

emissions/ 

process 

update

Facilities 

that have 

Closed 

since 2005

Wood Furniture 

Manufacturing

67 30 7 8 5 17

Ship Building 0
53

Commenter 40 indicated that 50 of the 67 North Carolina (NC) facilities identified by EPA 

should be included in the risk assessment. Facilities that are closed (17) should be removed from 

consideration. Of the remaining 50 facilities, commenter 40 requested that the 13 facilities with 

risks above threshold levels be reconsidered for cancer and non-cancer risk, as the commenter 

has reported changes to emissions or processes.

Response: The EPA acknowledges receiving updated information concerning these 

facilities.. These facilities are not driving risk in the risk assessment for wood furniture facilities.

The updated information has no effect on risk estimates for the source category because the 

changes to emissions are minor and correspond to very low risk facilities (i.e. HQ < 0.1 and MIR 

< 0.1 in 1 million). Only one facility had an increase in emissions and that facility had an MIR of 

0.071 in 1 million and a maximum HQREL= .0021. The facilities emission changes were by far 

less than an order of magnitude and a corresponding order of magnitude change to the MIR and 

HQ risks corresponds to thresholds less than 1 in 1 million and 1, respectively. No information in 

the emissions database has changed as a result of these commenters.

31. Comment: Two commenters (38 and 49) stated that the facility with the highest reportable 

formaldehyde emissions (Kitchen Kompact located in Jeffersonville, IN) is not a good 

representative wood coating manufacturing facility. 

The commenters offered the following reasons:

a. the facility finishes products 4 days a week (as opposed to EPA‘s 5 day assumption); 

b. the facility utilizes a higher VOC product without a control device; and 

c. the facility has all operations at one facility (other large facilities may spread operations 

over several facilities). 

Commenter 49 further believed that it is arbitrary for EPA to set the formaldehyde limit based on 

problematic data indicating that 3% (more likely 1%) of facilities had formaldehyde emissions 

that could result in exceedances of the acute REL. The commenter offered the following reasons 

why EPA‘s conclusion that 11 facilities (about 3% of the facilities) had formaldehyde emissions 

that could result in exceedances of the acute REL is problematic:

a. EPA identified four facilities for emissions verification – two of which had formaldehyde 

emissions – Chromcraft which no longer uses coatings that contain or emit formaldehyde 

and Kitchen Kompact – which has less formaldehyde emissions than reported and is not a 

good representative facility. Both verification facilities are problematic and indicate that 

the facility data used in the risk assessment is suspect.

b. Three of the 11 facilities either no longer use formaldehyde containing products 

(Chromcraft) or the facilities have lower production than EPA identified (Kitchen 

Kompact and Legacy Cabinets). Removing Chromcraft, only 10 or 2.5% of the facilities 

had emissions that could result in exceedances of the acute REL.

c. It was clear from Table 4 that the HEM-3 screening results were problematic and that the 

refined modeling approach that utilized aerial photographs of the facilities identified two 

major problems with the risk assessment:
54

The REL for several facilities was lowered since the polar ring needed to be corrected 

due to GPS errors and; 

an evaluation of the aerial map indicated that the REL needed to be lowered in some 

cases by as much as 74%. Moving the ―polar ring‖ has a significant impact on the risk 

assessment, and while developing refined acute risks based on review of aerial maps 

is better it is subjective at best. 

d. Three of the 10 facilities had refined predicted acute risks greater than 3, the remaining 7 

had refined predicted acute risks of less than 3, a majority of these had predicted acute 

risks just above 1 (1.5, 1.5, 1.6 (Legacy Cabinets which should be changed), 1.8). The 

commenter suggested that these facilities be discounted as well. 

After removing these data points, commenter 49 noted that there are 6 facilities (approximately 1 

percent of the facilities) with acute risks greater than 1. The commenter noted that setting a 

standard based on 6 facilities (or 1% of all wood furniture facilities) is unjustified and arbitrary.

Response: The EPA acknowledges that there have been changes to formaldehyde 

emissions since 2005. According to the comments received as well as phone conversations with 

several facilities, the EPA has received indications that facilities have changed and lowered 

formaldehyde emissions, subsequent to the 2005 NEI data. These updates, however, are not 

being used to replace the 2005 NEI data because data were not provided to support the 

assertions. Because the data are unverified, the EPA used source data from 2005 NEI to keep a 

verified source for purposes of risk assessment. As discussed in the preamble for this rule 

making, we are not adopting any new or additional requirements based on the risk assessment 

under section 112(f). We have found all risks to be acceptable for this rule making. 

32. Comment: Commenter 39 stated that, based on EPA‘s risk analysis, implementation of the 

current Subpart JJ, promulgated on December 7, 1995, has been very effective in risk reduction. 

The commenter further stated that their facilities have reduced formaldehyde emissions by nearly 

90% since the baselines were determined. The commenter recommended continued reliance on 

the Formulation Assessment Plan approach. The provisions require facilities to provide a written 

notification if annual usage of formaldehyde exceeds a baseline level and provide reasons for 

exceedance of the baseline.

Response: We agree with the commenter that Wood Furniture facilities have reduced 

formaldehyde emissions and resulting risk under the existing Subpart JJ MACT standard. As 

discussed in the preamble to the final rule, we also conclude that the existing MACT standard for 

Wood Manufacturing, which includes the Formulation Assessment Plan requirement, provides 

an ample margin of safety.

33. Comment: Commenter 40 agreed with the way in which EPA estimated cancer and noncancer risk. However, the commenter noted that the state of North Carolina also has an air toxics 

program which is a ―risk-based‖ regulatory program designed to protect public health by limiting 

emissions of toxic air pollutants (TAPs) from man-made sources. Concentrations of airborne 

chemicals, called Acceptable Ambient Levels (AALs), were established above which the 

substance may be considered to have an adverse effect on human health. North Carolina has 

developed AALs for 97 TAPs for cancer, chronic and acute exposures. The commenter stated 
55

that these may be more appropriate to use when estimating risk from North Carolina facilities 

and would provide consistency with the ongoing state program. 

Response: For EPA to fully evaluate the NC AALs, the documents used to set the AALs 

should be provided to the EPA to identify what studies were utilized as the basis of the dosevalue for each chemical. A review of the TAP‘s regulated by NC did not identify any toxic air 

pollutants in which EPA did not have either a cancer or non-cancer dose-response value. The 

dose-response hierarchy established by EPA has been approved by EPA‘s SAB and represents 

the latest toxicity findings that have been peer reviewed and are publically available. A 

modification to this hierarchy is not warranted at this time.

34. Comment: Multiple commenters (40, 42, 45, 46, 49, 50, 51, and 55) offered comments on 

the use of formaldehyde dose-response values.

Commenters 42 and 45 supported the use of the Integrated Risk Management System (IRIS) 

dose-response value for formaldehyde in the risk assessment.

Commenter 45 stated that it is not only appropriate for EPA to end its use of the CIIT Centers for 

Health Research risk value for formaldehyde emissions, doing the contrary would be arbitrary, 

capricious and unlawful. The commenter supported the IRIS value because it is more than 2,000 

times greater than the CIIT value and thus more health-protective.

Commenter 42 also provided support for EPA‘s proposal to revert to the use of the Integrated 

Risk Management System (IRIS) dose-response value for formaldehyde in the risk assessment. 

The commenter referenced the World Health Organization‘s concerns about formaldehyde. The 

commenter supported the continued use of the existing IRIS factors until the review process is 

completed. The commenter further urged an acceleration of the IRIS review.

Alternatively, 6 commenters (40, 46, 49, 50, 51 and 55) did not support the use of outdated and 

overly conservative models, such as the Integrated Risk Management System (IRIS) doseresponse value.

Commenter 46 stated that EPA must utilize the best available science in its risk assessment, 

which is not the IRIS value. The commenter noted that EPA has previously determined that the 

IRIS value ―no longer represents the best available science in the peer reviewed literature.‖ 69 

Fed. Reg. 18,327, 18,333 (Apr. 7, 2004). Commenter 46 noted:

To the extent the re-assessment [of the IRIS value] may constitute the best available 

science, EPA should delay the final rulemaking until the reassessment is completed 

and it can conduct a revised assessment. It must give the public an opportunity to 

comment on any revised assessment and any changes to EPA‘s proposal prior to 

issuing a final rule. 

At a minimum, EPA must weigh the risk estimates based on the CIIT values against 

estimates that rely on the outdated IRIS value. EPA appropriately notes that the CIIT 

value generates estimates of maximum individual excess lifetime cancer risks that are 

50 percent less than comparable estimates based on the formaldehyde IRIS value. 

Similarly, the CIIT based cancer incidence estimates are reduced by 30 percent. 

Based on EPA‘s use of the older IRIS value, it has proposed a new standard under 
56

section 112(f) to address the ample margin of safety requirement for wood furniture 

manufacturing. But EPA‘s findings are insufficient to support a new standard. EPA 

asserts that the new standard would reduce the maximum acute hazard quotient value 

based on the CalEPA Reference Exposure Level (―REL‖) for formaldehyde from 7 to 

3, and will reduce the maximum lifetime individual cancer risk from 20-in-1 million 

to approximately 10-in-1 million, both based on the actual emissions level. But, this is 

not sufficient grounds to determine that a new standard is needed to ensure an ample 

margin of safety, particularly where EPA only found that formaldehyde emissions 

from 11 facilities (about three percent) that ―could‖ result in exceedances of the acute 

REL, indicating a potential for acute non-cancer risks of concern. As EPA notes these 

estimates are based on highly ―multiple conservative assumptions.‖ Indeed, EPA ―did 

not see a potential for any facility to cause exceedances of the acute ERPG–1 or 

AEGL–1 levels.‖ Since EPA found an acceptable level of risk, these overly 

conservative estimates, which are not based on the best available science, are 

insufficient to justify a new standard to address ample margin of safety.

Commenter 40 stated:

EPA‘s use of the 1991 Integrated Risk Management System (IRIS) dose-response 

value for formaldehyde may not be appropriate given the high level of scientific 

debate and inconsistency surrounding the health effects of formaldehyde. 

Recommendations of limiting formaldehyde use based on risk modeling results using 

such a conservative value may require further consideration, especially as 

formaldehyde is currently under review in IRIS. [The commenter] encourages EPA to 

accelerate its IRIS review of formaldehyde and consider delaying ―use limits‖ for the 

Wood Furniture Manufacturing Operations source category until the IRIS review is 

completed.

Commenter 51 stated:

Contrary to IQA guidelines, EPA inappropriately applies the outdated IRIS doseresponse values in determining formaldehyde inhalation exposure risk in support of 

the Proposed Rule. In 2004, EPA determined that ―the dose-response value in IRIS is 

based on a 1987 study, and no longer represents the best available science in the peer 

reviewed literature.‖ 69 Fed. Reg. 18327, 18333 (Apr. 7, 2004). EPA went on to state 

that ―the CIIT modeling effort represents the best available application of the 

available mechanistic and dosimetric science on the dose-response for portal of entry 

cancers due to formaldehyde exposure.‖ Id. This determination led to the 

incorporation of the CIIT dose-response value for formaldehyde exposure in risk 

assessments supporting regulatory action. In the underlying risk assessment for the 

Proposed Rule, however, EPA reverses its position on what constitutes the best 

available science by stating that EPA no longer considers ―the CIIT URE value health

protective, and we are again using the EPA‘s current value on IRIS, which was last 

revised in 1991....‖ 75 Fed. Reg. 80220, 80228 (Dec. 21, 2010).

The CIIT‘s construction of a biologically based dose-response (BBDR) model to 

determine an appropriate dose-response value by utilizing a detailed understanding of 

formaldehyde‘s cancer mode of action (MOA) is a superior model for predicting 
57

cancer risk than the 1991 IRIS model. Further, current science supports the robustness 

of the CIIT dose-response model. The sensitivity of the model was questioned based 

on inappropriate manipulation, rebutting EPA‘s assertion that the variability of the 

model is ―not supportive of interpreting the CIIT model results as providing a 

conservative (health-prospective) estimate of human risk.‖ Id. (citing Crump et al., 

2008). In fact, an NAS panel has already reviewed the CIIT model and determined 

that it is superior to the 1991 IRIS value:

The available evidence, however, strongly suggests that the risk from formaldehyde 

at high doses demonstrated in animals studies cannot be extrapolated to lower doses 

using the EPA‘s approach (Conolly et al. 2003; Gaylor et al. 2004). The more recent 

CIIT assessment results in a theoretical cancer risk well below the U.S. Department 

of Defense ―acceptable‖ risk level of 1 in 10,000, even for lifetime exposure at the 

0.3-ppm 90-day CEGL. The subcommittee concluded that the CIIT assessment more 

accurately reflects the scientific weight of evidence for formaldehyde carcinogenicity 

than does EPA‘s approach (NAS, 2007, p. 131).

EPA should not ignore the NAS‘s conclusion by reverting to a twenty year old IRIS 

assessment value that is not supported by the best available science.

Moreover, there are substantial limitations associated with the 1991 IRIS value that 

makes its use in setting emissions standards inappropriate. Substantial research has 

been conducted in the past 20 years that invalidates the IRIS dose-response value for 

formaldehyde exposure. The NAS is currently reviewing EPA‘s Draft IRIS 

Assessment of formaldehyde. EPA should delay the finalization of the Proposed Rule 

until the NAS review is completed in March 2011, so that EPA can fully incorporate 

the NAS‘s findings regarding formaldehyde and risk into the emission standards for 

the Wood Furniture Manufacturing source category.

Commenter 55 stated that the decision to discontinue use of CIIT model is inappropriate. The 

CIIT model should continue to be used to inform formaldehyde risk assessments. The criticisms 

of the model by Crump and colleagues lack foundation because the manipulations and alterations 

of the model on which they are based did not have an adequate basis in the underlying biology.

Commenter 49 referenced the National Academy of Science (NAS) formaldehyde re-evaluation: 

With respect to the assessment of cancer risk from occupational and environmental 

exposures, [the commenter] agrees with the agency that ―formaldehyde is a unique 

case.‖ Since 2004, EPA has relied on the CIIT Centers for Health Research (formerly 

the Chemical Industry Institute of Toxicology) dose-response value for formaldehyde 

because if was based ―on better science than the IRIS dose-response value.‖ The 

CIIT‘s risk assessment of formaldehyde incorporated both mechanistic and 

dosimetric information on formaldehyde, which is essential to demonstrating the 

underlying basis for carcinogenicity. While the agency may currently question some 

of the modeling assumptions used in the CIIT effort, it cannot selectively revert to an 

IRIS reference value that, in addition to being dated, having been established in 1991, 

is also currently being re-evaluated by the (NAS) through the National Research 

Council (NRC).
58

The NAS review is expected to be completed by March of 2011, and given that it will 

be considering the most recent published evidence on the possible mechanism for 

formaldehyde-related carcinogenesis, it will likely substantially change the 

underlying basis for any and all proposed formaldehyde exposure-related residual risk 

standards. Having closely monitored efforts at the International Agency for Research 

on Cancer (IARC) and its recent affirmation that formaldehyde be classified as a 

known human and animal carcinogen, causing nasopharyngeal cancer (pending IARC 

Monograph 100, conclusions developed October 2009 and as of yet, full 

documentation unpublished but summaries available at 

http://monographs.iarc.fr/ENG/Meetings/index1.php. In Monograph 100, IARC also 

cites limited epidemiological evidence for leukemia in humans is available; however 

inconsistent across studies. While IARC affirms both genotoxicity and cytotoxicity 

events are critical for formaldehyde to develop nasal carcinogenicity in rats, the 

mechanistic data for leukemia was not well established in the IARC discussions.

We note that formation of DNA adducts is often described as a key event in initiating 

carcinogenesis. A recent study by Lu et al (see Lu et al, ―Distribution of DNA 

Adducts Caused by Inhaled Formaldehyde Is Consistent with Induction of Nasal 

Carcinoma but Not Leukemia‖, Toxicological Sciences, 116(2), 441-451, 2010) 

explores adduct formation in a straightforward manner looking at endogenous and 

exogenous sources of formaldehyde. The results show that ―exogenous formaldehyde 

induced... adducts in DNA from rat respiratory nasal mucosa but did not form 

adducts in sites remote to the portal of entry‖ (Lu, 2010). In contrast, high amounts of 

endogenous formaldehyde adducts were present in all tissues examined. This study 

provides strong evidence supporting a mode of action for the carcinogenesis of

inhaled formaldehyde in respiratory nasal epithelium, but does not support the 

biological plausibility that inhaled formaldehyde also causes leukemia.

[The commenter] cites all of this activity to reinforce the need to properly 

characterize the underlying cancer risk associated with formaldehyde exposure prior 

to establishing any revised proposal or final residual risk rule. Given the unique 

nature of formaldehyde exposure and the widespread impacts of any proposed or final 

rule, it is imperative that the agency consider all emerging science on the matter. To 

emphasize this point the commenter noted that, by the agency‘s own admission, the 

estimated maximum individual excess lifetime cancer risk would be reduced by 50 

percent and the cancer incidence would be reduced by 30 percent if the CIIT values 

were used instead of the IRIS. Similarly, a finding by NAS/NRC panel that the 

mechanistic data does not support prior leukemia findings would dramatically alter 

the need for a more stringent residual risk rule. 

Commenter 50 noted that placing any further limits on formaldehyde would be premature until 

the NAS report on the subject has been received (end of February 2011) and the IRIS process 

completed. The commenter noted:

According to the proposal, ―The total estimated cancer incidence due to the actual 

emission from the source category is 0.005 excess cancer cases per year, or one case 

in every 200 years.‖ This hardly serves as a basis for further regulation. Also, six of 

the 11 facilities used as the basis for concern were at ―2‖ out of a possible ―7‖ on the 
59

risk scale and the companies at the top of the scale at ―6‖ or ―7‖ account for less than 

1-2% of the market. This should not be the basis for imposing further restrictions on 

the 98% or the industry that are performing satisfactorily. In today‘s economy, 

companies would need at least three years to comply if the proposed changes were 

approved.

Response: In 2004, the EPA determined that the Chemical Industry Institute of 

Toxicology (CIIT) cancer dose-response value for formaldehyde (5.5 x 10-9per μg/m3) was 

based on better science than the IRIS dose-response value (1.3 x 10-5per μg/m3), and we 

switched from using the IRIS value to the CIIT value in risk assessments supporting regulatory 

actions. Based on subsequent published research, however, EPA changed its determination 

regarding the CIIT model, and in 2010 EPA returned to using 1991 IRIS value. The National 

Academy of Sciences (NAS) completed its review of the EPA‘s draft assessment in April of 

2011 (http://www.nap.edu/catalog.php?record_id=13142), and EPA has been working on 

revising the formaldehyde assessment. The EPA will follow the NAS Report recommendations 

and will present results obtained by implementing the biologically based dose response (BBDR)

model for formaldehyde. The EPA will compare these estimates with those currently presented 

in the External Review draft of the assessment and will discuss their strengths and weaknesses.

As recommended by the NAS committee, appropriate sensitivity and uncertainty analyses will be 

an integral component of implementing the BBDR model. In the interim, we will present 

findings using the 1991 IRIS value as a primary estimate, and may also consider other 

information as the science evolves. The EPA notes that risk estimates based on both the IRIS and 

the CIIT unit risk estimates for formaldehyde were presented in the proposal for this final rule 

and that the risks were acceptable in both cases. 

35. Comment: Commenter 48 has previously submitted extensive data to the EPA under the 

OECD/SIDS program for the Mono-Ethylene Glycol Ethers, Di-Ethylene Glycol Ethers, and TriEthylene Glycol Ether (High Boiling Glycol Ethers) Categories. These submissions included 

dossiers of robust study summaries, test plans and SIDS Initial Assessment Reports (SIARs) for 

all of the common ethylene glycol ethers. These documents have been peer reviewed at various 

SIDS Initial Assessment Meetings (SIAMs). The EPA has access to these documents and can 

review the information contained in them, which supports the trend toward decreasing toxicity as 

the size of the alkyl group or the number of ethylene glycol units is increased.

Response: 26 of the 92 facilities reporting glycol ether emissions provided speciated 

emissions data for glycol ethers which represented approximately 10% of the glycol ether 

emissions emitted from the source category. This limitation as well as the limited number of 

acute reference values available for individual glycol ether compounds in the SIDS assessments 

supports the use of a conservative approach (i.e., health protective) of using the glycol ether 

with the lowest reference value (ethylene glycol methyl ether or EGME) as a surrogate for glycol 

ethers without available reference values. A review of the 11 individual speciated glycol ethers 

reported to the emission inventory only 3 had SIDS data. To the extent that these studies appear 

in the peer-reviewed scientific literature at the time of development of an IRIS health 

assessment, they would be considered along with the entire body of literature.
60

36. Comment: Commenter 48 stated EPA overlooked available studies for DGBE when 

deriving a provision peer reviewed toxicity value (PPRTV) in 2009: 

Page 80242 of the proposed rule discusses the derivation of a PPRTV for DGBE. The EPA 

states, "Inhalation toxicity information for DGBE is essentially limited to the results of a 

single 5-week study in rats (Gushow et al., 1984), which resulted in slight vacuolization of 

the liver cells consistent with fatty change. An uncertainty factor of 3000 was applied in 

deriving the PPRTV, and confidence in the provisional RfC (p-RfC) value is low." The 

EPA should be aware that other studies for DGBE have also been available, and robust 

summaries of these studies were submitted to the EPA in a dossier and SIAR for the 

Diethylene Glycol Ethers Category in 2005. These documents were reviewed by the EPA 

in 2005 and also peer reviewed at OECD/SIDS SIAM 21 in 2005 with participation by the 

Agency. These studies include the following: a 1992 BASF 90 day inhalation study in the 

Wistar rat, a 13 week dermal study in the SD rat by Auletta et al., 1993, and finally a 2002 

study in drinking water for 91 days in the F344 rat by Johnson et al. The references for 

these studies are provided below. The commenter suggested that EPA should review these 

studies and again derive the PPRTV, taking these studies into consideration. It is likely that 

use of these studies may increase the confidence in the RfC value, and also reduce the 

3000-fold uncertainty factor.

Response: The EPA did not use the DGBE PPRTV value in the risk assessment 

supporting this proposed action. The reference concentration (RfC) for EGME from IRIS was the 

value used to represent the toxicity of glycol ethers without hierarchically based non-cancer 

reference values.

37. Comment: Commenter 45 stated EPA‘s sole justification for setting this formaldehyde 

limit at 400 lbs. per rolling 12-month period appears to be the fact that this level is already 

contained in the existing MACT as a work practice requirement:

EPA has stated that adopting this level as an emission standard would create 

―either no or minimal additional costs.‖ Id. at 80,247. This number was chosen in 

1995, however. Where this number came from initially is unclear. While it may be 

convenient for industry to use a level with which it is already familiar and that 

would incur little or no extra cost, EPA has not provided a reasoned explanation 

based on the required statutory health-based criteria for choosing this limit, rather 

than a more stringent limit. The record does not show why this is the appropriate 

limit to set as a residual risk standard in today‘s world.

EPA must complete this analysis and set an appropriately protective 

standard to satisfy CAA § 112(f)(2). Specifically, EPA must consider and address 

how much emissions would be reduced if EPA set a lower standard, and what level 

of emission standard is required to provide an ―ample margin of safety.‖ 42 U.S.C. 

§ 7412(f)(2). EPA must address what emission standard would be needed to bring 

the MIR down to 1-in-1-million as the statute directs. Id. EPA must address what 

standard is needed ―to provide maximum feasible protection against risks to health‖ 

by ―protecting the greatest number of persons possible‖ to a lifetime risk level no 

greater than 1-in-1 million. 75 Fed. Reg. at 80,223 (quoting Benzene NESHAP). 
61

The need for this analysis is amplified by the fact that EPA has recognized 

numerous ―uncertainties related to the risk assessments, particularly for 

formaldehyde and glycol ether emissions.‖ Id. at 80,242-43. For example, EPA has 

stated that it is concerned that its risk analysis has failed to account for additional 

formaldehyde emissions that likely occur during curing and gluing. Id. at 80,243. 

The uncertain amount of additional risk unaccounted for provides another reason 

for EPA to set a more protective formaldehyde emission standard than the level 

chosen as a work practice standard in 1995.

Commenter 49 stated there is no approved method for estimating formaldehyde 

emissions and formaldehyde emissions from the cure process depend on multiple factors, 

including conditions under which the coating was applied, customer specifications, air 

flow, temperature, humidity, moisture content, and the elapsed time from coating 

applications. According to the commenter, elaborate, costly testing would be required to 

estimate these emissions.

Response: The EPA is not finalizing the 400 pounds per rolling 12-month period

formaldehyde use limit as proposed under 112(f) of the CAA. See section IV.B of the preamble 

for a discussion of the significant changes since proposal, including the decision to adopt the 400 

pound per 12 month limit only as a compliance alternative because of information received 

concerning cost-effectiveness of the proposed limit. Also see section IV.B of the preamble 

regarding our conclusion under CAA section 112(f)(2) that additional standards are not 

necessary to provide an ample margin of safety. Section 112(f)(2) does not direct EPA to address 

what emission standard would be needed to bring the MIR down to 1-in-1-million. On the 

contrary, the District of Columbia Circuit has upheld our interpretation of section 112(f)(2) that a 

1-in-1 million level of risk is an aspirational goal. See NRDC v. EPA, 529 F.3d 1077, 1082 (D.C. 

Dir. 2008). As explained by the court, ―[s]ubsection 112(f)(2) only mandates that residual risk 

standards  ̳provide an ample margin of safety to protect public health.‘ If EPA determines that 

the existing technology-based standards provide an  ̳ample margin of safety,‘ then the Agency is 

free to readopt those standards during the residual risk rulemaking.‖ Id. at 1083 (italics omitted). 

This statement applies to EPA‘s action in this rulemaking, with the additional step of adopting 

standards under section 112(d)(6).

Instead, as discussed in the preamble, the EPA is promulgating a formaldehyde standard 

under section 112(d)(6). All wood furniture coatings and contact adhesives must be low- or noformaldehyde (concentration not to exceed 1 percent by weight formaldehyde) or, as a 

compliance alternative, formaldehyde emissions from wood furniture facilities must not exceed 

400 pounds per rolling 12-month period. The compliance options are designed to promote 

continuing reductions in formaldehyde emissions from wood furniture facilities without 

requiring equipment changes that are not cost effective. The formaldehyde limits will avoid 

constraining the production of wood furniture facilities while encouraging them to maintain or 

decrease levels of formaldehyde in coatings and contact adhesives. We are not estimating any 

quantified formaldehyde emissions reductions from the formaldehyde limits and are concluding 

that the existing Wood Furniture NESHAP provides an ample margin of safety under section 

112(f).
62

The 400 pounds per 12 month period formaldehyde limit is based on the threshold level 

in Table 5 of the 1995 NESHAP, which itself was a result of negotiations with industry. In this 

RTR we used the familiar numerical threshold for formaldehyde emissions and made it a level 

not to exceed. This was proposed to reduce the HQ of formaldehyde from 7 to 3 in a cost 

effective manner. Between proposal and promulgation, it became clear through public comments 

that this limit was cost effective for the source category. As discussed in greater detail in section 

IV of the preamble, this limit is being finalized as a compliance alternative under section 

112(d)(6).

The science is unclear as to the degree of formaldehyde curing under different 

environmental conditions. We did not receive any public comments containing or referring to 

any emissions information on formaldehyde emissions from curing at wood furniture facilities

that would aid in understanding and regulating cure emissions. Until there is data relevant to how 

cure formaldehyde is formed and in what quantities, we are unable to set limits for such 

emissions.

38. Comment: Commenter 45 noted that ethyl benzene is the primary risk driver for cancer, 

but EPA did not address this pollutant: 

[EPA] does not consider or address whether this level of facility-wide risk is 

acceptable at facilities where this source category is contributing so significantly. 

EPA must do so to complete its section 112(f)(2) duty. This is the time for EPA to 

exercise its full authority to reduce health risk to achieve the statutory target of 1-in-1 

million. Its failure to consider regulatory options to address this residual risk is 

arbitrary and capricious. At minimum, EPA should consider whether to set an ethyl 

benzene standard in order to reduce this residual risk. It also should consider 

requiring extra work practice, reporting, monitoring, and other measures for facilities 

that have the level of emissions putting them into this highest risk category. 

Response: As discussed in section IV.B of the preamble to the final rule, we do not 

interpret section 112(f)(2) as requiring a 1 in a million MIR level as a  ̳ ̳bright line‘‘ mandated 

level of protection for residual risk standards. In determining the ample margin of safety, health 

risk is one factor that we consider, from this source category covered under the rule and its 

contribution to facility-wide risk, along with other relevant factors. Balancing these and other 

factors with the ability to achieve meaningful risk reduction benefits is a critical component of

ample margin of safety determination in the residual risk rulemaking process. For the wood 

furniture manufacturing source category we found that risks associated with ethyl benzene and 

all the other HAP emitted were ―acceptable‖ and the existing MACT protects the public health 

with an ―ample margin of safety‖, with no additional controls being adopted under section

112(f). 

39. Comment: Commenter 55 stated that the use of a default low-dose linear cancer risk 

assessment approach is completely inconsistent with the strong scientific evidence of a threshold 

mode of action for formaldehyde: 
63

The only available risk assessment options for formaldehyde that are consistent with 

the evidence regarding its mode of action are the default nonlinear approach (margin 

of exposure calculation based on a point of departure in the range of the experimental 

data) or use of the CIIT BBDR model. However, the default nonlinear approach does 

not result in a quantitative risk estimate. Thus the CIIT BBDR model remains the 

most scientifically appropriate method currently available for estimating quantitative 

human cancer risk from exposure to formaldehyde. 

The proposed EPA cancer risk assessment involves linear extrapolation through the 

origin from points-of-departure for increased tumor incidence. This default approach 

is not well designed to account for the dose response and dose-dependent transitions 

for endogenous compounds, like formaldehyde, that have significant physiological 

background levels in tissues but are toxic at high exposures. Our studies integrating 

genomics, histopathology and pharmacokinetics (Andersen etal., 2010) indicate that 

at exposure concentrations below 1 ppm, inhalation of formaldehyde is not expected 

to cause any appreciable increase in target tissue concentrations of free formaldehyde. 

Dose-dependent transitions for mutation are present for DNA-reactive compounds 

(Swenberg et al., 2008) with low dose damage adequately repaired and high doses 

leading to such extensive damage that DNA integrity cannot be maintained.

Response: In 2004, the EPA determined that the Chemical Industry Institute of Toxicology 

(CIIT) cancer dose-response value for formaldehyde (5.5 x 10-9 per μg/m3) was based on better 

science than the IRIS cancer dose-response value (1.3 x 10-5 per μg/m3), and we 

switched from using the IRIS value to the CIIT value in risk assessments supporting 

regulatory actions. However, subsequent research published by the EPA suggests that the 

CIIT model was not appropriate and in 2010 EPA returned to using the 1991 IRIS value, 

which is more health protective. EPA has been working on revising the formaldehyde 

IRIS assessment and the National Academy of Sciences (NAS) completed its review of the 

EPA‘s draft in May of 2011, (http://www.nap.edu/catalog.php?record_id=13142). EPA is 

reviewing the public comments and the NAS independent scientific peer review, and the draft 

IRIS assessment will be revised and the final assessment will be posted on the IRIS database. In 

the interim, we will present findings using the 1991 IRIS value as a primary estimate, and may 

also consider other information as the science evolves

40. Comment: Commenter 52 noted the following:

Even though the HQ based on the REL is predicted to be above one for certain 

facilities, EPA ―did not see a potential for any facility to cause exceedances of the 

acute ERPG-1 or AEGL-1 levels.‖ Thus, given the admitted conservatism of the 

modeling methods and assumptions, and the admitted over-conservatism of the REL, 

the fact that certain facilities are predicted to have a maximum HQ above the REL 

does not provide an adequate basis for concluding that additional control measures 

are needed to provide an ample margin of safety. 

Response: The REL values provided by California EPA are not deemed by EPA to be 

overly conservative; by definition the values represent an acute health-protective level of 
64

exposure, with no risk anticipated below those levels, even for repeated exposures to sensitive 

populations such as children and the elderly. It is therefore appropriate for us to utilize the RELs 

in concert with AEGL values which are levels at which we expect to see mild effects in the 

general population in order to determine what emission limits provide an ―ample margin of 

safety‖ (AMOS). AMOS does not define a ―rigid line(s) of acceptability‖ but requires us to use 

the two-step process laid out in the Benzene NESHAP to consider a variety of measures of risk 

to public health, costs and feasibility of controls to reduce potential risks as well as the 

uncertainties of our assessment, See 75 FR 80222 – 80225. Using our analytical approach with 

the data provided, we concluded it is unlikely that HAP emissions from this source category pose 

significant acute health risks and that control measures will not be necessary, based upon cost 

feasibility and the conservative nature of our exposure and toxicity assessment.

41. Comment: Commenter 52 noted the following:

Similarly, as noted above, EPA asserts that the new 400 lb/yr limit is warranted 

because it ―will reduce the maximum lifetime individual concern risk from 20-in-1 

million to approximately 10-in-1 million.‖ However, EPA‘s risk assessment also 

reveals that the cancer incidence associated with HAP emissions from this source 

category is ―1 [case] in every 200 years.‖ This rate of incidence already is so 

diminishingly small that there is no rational basis for EPA to impose additional 

control measures in the interest of reducing it further. In short, the existing MACT 

standard assures an ample margin of safety with regard to potential chronic effects. 

Finally, even if maximum risks at certain facilities did not have an ample margin of 

safety, EPA must consider targeting risk reduction measures to those facilities that 

present the unreasonable risk. It is unfair and unnecessary for facilities that have 

managed emissions in such a manner as not to pose an unacceptable risk to be 

required to adopt risk reduction measures. EPA could target the risk management 

approaches to the subset of facilities that are―high risk. If a facility wanted to 

undertake alternative risk reduction measures to get below the―risk threshold‖ for 

either acute or cancer risks, it could choose to do so and avoid the use of reformulated 

coatings and adhesives. This creates an incentive for the facility to find the least cost 

risk reduction strategy while still meeting an acceptable risk level. 

Response: No new requirements are included in the final rules for these source 

categories to address or reduce residual risk, so these comments are not germane. To the extent 

the commenter has concerns with actions taken in future residual risk reviews, those concerns 

should be raised at that time

42. Comment: Commenters 39 and 49 commented on the acute HQ.

Commenter 49 stated that similar to formaldehyde, it was clear from Table 4 that the HEM-3 

screening results were problematic and that the refined modeling approach that utilized aerial 

photographs of the facilities identified two major problems with the risk assessment 1). The REL 

for several facilities was lowered since the polar ring needed to be corrected due to GPS errors 

and 2) an evaluation of the aerial map indicated that the REL needed to be lowered in some cases 

by as much as 70%. The commenter noted that it is arbitrary that EPA used the REL for EGME 
65

as opposed to using the REL for EGBE (delisted HAP) which accounted for 25% of the glycol 

ether emissions from wood furniture manufacturing, especially since it appears that from Table 4 

(Glycol Ether Speciation Profile) that EGME is not used at all in the industry.

Commenter 39 noted that the high acute HQ of 10 is due to EPA's use of the REL for ethylene 

glycol methyl ether, the most protective reference value for this category of compounds, to 

estimate risk from individual compounds in the group. This extremely conservative assumption 

significantly overestimates the risk from glycol ether emissions. 

Response: We acknowledge that refining our screening assessments of potential acute 

impacts utilizing aerial photography in some cases lowered the estimated maximum Hazard 

Quotient for acute non-cancer impacts. We also acknowledge that the use of the most healthprotective glycol ether REL as the threshold value for all glycol ethers without acute REL values 

more likely overestimates these potential acute impacts than underestimates them. This 

approach was utilized because of the large amount of the reported glycol ether emissions which 

were reported as ―unspeciated‖. Approximately 70% of facilities reporting glycol ether 

emissions were unspeciated. There are no AEGL or ERPG values available for any glycol 

ethers; this further limits our ability to interpret the potential acute impacts of glycol ethers. 

Nonetheless, even though our maximum estimated acute HQ from glycol ether emissions 

remains above 1, we believe it is unlikely that glycol ether emissions from this source category 

pose significant acute health risks based upon the conservative nature of our exposure and 

toxicity assessment.

43. Comment: Commenter 48 stated the CalEPA Reference Exposure Level for EGME is an 

inappropriate choice of REL for EGPE. EGME is the lowest molecular weight member of the 

ethylene glycol ether series:

The REL for EGME is based on decreased testes weight and degenerative changes in 

the testicular germinal epithelium. A CalEPA REL also is available for ethylene 

glycol ethyl ether (EGEE), and is also based on testicular degeneration. These types 

of reproductive organ effects are unique to EGME and EGEE, but no such effects 

have been seen in other, higher members of the ethylene glycol ether series starting 

with EGPE. Based on the observed reproductive organ effects for EGME and EGEE, 

these glycol ethers were discontinued as commercial products by the major U.S. 

manufacturers many years ago. Since the reproductive toxicity effects are limited to 

EGME and EGEE, and these substances are no longer available in industrial 

commercial quantities, it is inappropriate to use the REL for EGME to characterize 

EGPE and the higher molecular weight members of the ethylene glycol ether series.

The commenter derived an REL for EGPE following the methodology of CalEPA. The 

commenter provided a comment attachment containing the derivation of a proposed REL of 

4.3 mg/m3 for EGPE. 

Unlike the 0.060 and 0.070 mg/m3 RELs calculated for EGME and EGEE, 

respectively, based on testicular degenerative effects, the proposed 4.3 mg/m3 REL 

for EGPE is based on observed hematological changes. No testicular degeneration has 

been observed for EGPE. The findings for EGPE are more consistent with the 

hematological changes observed for EGBE, for which an acute REL of 14 mg/m3has 
66

been assigned based on irritative effects. In both cases, the hematological effects are 

seen in rats and mice, which are more sensitive to hemolysis than human beings. An 

REL of 4.3 mg/m3for EGPE based on hematological effects is consistent with the 

effects seen in higher glycol ethers, such as EGBE, and serves as a conservative lower 

boundary for the ethylene glycol ethers series.

Response: 26 of the 92 facilities provided speciated emissions data for glycol ethers which 

represented approximately 10% of the glycol ether emissions emitted from the source category. 

This limitation as well as the limited number of acute reference values available for individual 

glycol ether compounds in the SIDS assessments supports the use of a conservative approach 

(i.e., health protective) of using the glycol ether with the lowest reference value (EGME) as a 

surrogate for glycol ethers without available reference values. A review of the 11 individual 

speciated glycol ethers reported to the emission inventory only 3 had SIDS data. To the extent 

that these studies appear in the peer-reviewed scientific literature at the time of development of 

an IRIS health assessment, they would be considered along with the entire body of literature.

B. FORMALDEHYDE LIMIT

44. Comment: Five commenters (39, 43, 49, 50, and 52) disagreed with the 400 lb/year 

formaldehyde limit. 

Commenters 49 and 52 noted that limiting formaldehyde emissions from the wood furniture 

manufacturing operations source category is not supported by EPA‘s risk analysis and is 

therefore arbitrary. Commenter 49 noted that the total estimated cancer incidence due to actual 

emissions is 0.005 excess cancer cases per year or one case in every 200 years. 

Commenter 43 further stated that the limit is not necessary because formaldehyde emissions are 

likely to decrease further during the 2-year compliance period, without any further regulations.

Commenter 52 added that EPA is not justified in adopting this standard under §112(f)(2)(A) or 

§112(d)(6). On a related note, Commenter 50 questioned the authority of EPA to establish a 400-

pounds per year limit on formaldehyde emissions: 

Such a limit could result in as little as 40,000 gallons of now compliant finish to be the 

maximum usable quantity. This forces the use of alternative finishes, many of which do not 

provide performance necessary to meet existing industry performance standards (ANSI/KCMA 

A 161.1-2000), add cost ($500,000 to $1 million annually according to one estimate), and 

sometimes are more difficult to work with in the manufacturing process. The proposed 400-

pound limit on formaldehyde emissions should not be approved as a limit, but should remain as 

currently referenced in the existing regulation. Justification for the arbitrary limit of 400 pounds 

is lacking.

Commenter 49 noted that EPA chose the 400 lb/year Formaldehyde limit based on Table 5 of the 

MACT standard (List of VHAP of Potential Concern Identified by Industry) or 0.2 ton per year. 

Currently, facilities that exceed their baseline level would need no further explanation to 

permitting authorities if the exceedance is no more than 15% above the baseline, or if the usage 

is below the level in Table 5. According to the commenter, EPA did not note the number of 

facilities that utilize the formaldehyde limit versus the baseline exceedance option. Without this 
67

data it is not known if facilities use the 0.2 ton per year limit. The commenter assumed that most 

facilities comply via the exceedance of baseline option and not the 400 lb/year limit.

Commenter 39 stated that an absolute limit on total formaldehyde emissions will impose a 

significant production constraint. Take for example, a large cabinet manufacturing facility using 

a coating containing only 0.25% formaldehyde. If operations involve the use of 25,000 gallons of 

coating per year, formaldehyde emissions from this operation would total 500 pounds (assuming

a density of 8 pounds per gallon). Where a smaller operation can use a much higher 

formaldehyde content coating and still stay below the 400 pound threshold based on lower 

annual coating consumption. Larger facilities would need either to curtail operations, install 

costly controls, or replace the coating with an even lower formaldehyde content material at a 

considerable cost per ton of formaldehyde reduced. 

Commenter 39 also stated that EPA improperly presumed that a ―one-size fits all‖ approach to 

coatings and adhesives is feasible in the manufacture of wood furniture/cabinet products. EPA 

failed to take into account the performance, quality and customer requirements of these 

manufactured goods. 

The coatings and adhesives used for cabinet manufacture are specialized and may contain higher 

amounts of formaldehyde due to unique customer and environmental requirements.

Based on the data in the October 19, 2010 EPA Memorandum Impacts of Implementing a Limit 

on Formaldehyde Usage in the Wood Furniture Manufacturing Operations Source Category, the 

difference in price between coatings with formaldehyde and those that are formaldehyde-free is 

$3.02 per gallon. The commenter assumed a 1% formaldehyde content in the lower priced 

coating and a coating density of 8 pounds per gallon. The $3.02 per gallon additional cost for a 

formaldehyde-free coating would reduce formaldehyde emissions by 0.08 pounds for a cost of 

$37.75 per pound of formaldehyde eliminated or $75,500 per ton.

The commenter also evaluated the replacement cost for a topcoat containing 0.25% 

formaldehyde with a material containing only 0.005% formaldehyde. The price differential of 

$3.58 per gallon resulting in a cost of over $365,000 per ton of formaldehyde eliminated.

The commenter also noted the high cost of replacement of contact adhesives. Based on the 

relatively low formaldehyde content in the current materials used, an incremental cost of only $1 

to $2 per gallon could result in a cost exceeding $20,000 per ton. 

Response: Based on information received in the comments and further inquiry of the 

impacts of the proposed limit of 400 pounds formaldehyde per rolling 12-month period, EPA has 

revised the standard to require the formaldehyde content of coatings and contact adhesives to be 

less than or equal to 1 percent by weight with an alternate compliance option of the 400 pounds 

per rolling 12-month period formaldehyde use limit, as explained in the preamble. 

This approach is promulgated under the technology review requirements under the CAA 

section 112(d)(6)since the risks were deemed acceptable under the residual risk requirements 

under section 112(f)(2) of the CAA. This technology rule will not limit production or result in 
68

significant costs for high production facilities and will encourage further reductions in the future 

without compromising the integrity of product.

The EPA believes that most facilities will be able to cost effectively comply with the 1 

percent by weight formaldehyde limit.9This level of formaldehyde will be sufficient to create the 

cross-linking nucleation that provides durability to wood furniture products in many cases. By 

also having a formulation restriction as an alternative to the 400 pound per year limit, there are 

options for facilities so that there will not be restrictions of production.

45. Comment: Commenter 44 asked that the final rule clarify that affected sources may rely 

on the absence of a reported formaldehyde content value in the relevant MSDS as a sufficient 

basis upon which to report ―no formaldehyde‖ in the respective finishing material or contact 

adhesive. This would be inconsistent with EPA‘s prior position on this issue in Plastic Parts and 

Products NESHAP.

Response: As required by the final rule, sources will maintain certified product data 

sheets (CPDSs) from coating manufacturers that state the concentration of all chemicals within 

the coatings and contact adhesives. If formaldehyde is not listed on the CPDS, it may be assumed 

that it is not part of the formulation. 

46. Comment: Commenters 49 and 50 disagreed with the additional recordkeeping and 

reporting requirements.

Commenter 50 stated that imposing complicated additional recordkeeping and reporting 

requirements on 150 U.S. based cabinet manufacturers simply because their plants emit some 

formaldehyde is an overreach and an example of the type of regulatory excess both the President 

and Congress are trying to discourage.

Commenter 49 stated that the additional recordkeeping and reporting requirements will further 

burden an industry already facing overseas competition, even though EPA found the risks from 

this source category acceptable.

Response: The recordkeeping and reporting provisions being finalized are necessary to 

determine compliance with the 1% formaldehyde content limit or alternatively the 400 lb/12 

month formaldehyde usage limit. As discussed in the preamble for this rulemaking, the cost 

associated with reporting and recordkeeping is low. It is expected that any reporting and 

recordkeeping resulting from this rule is already occurring routinely within the industry. The 

commenters did not provide any specifics or data concerning recordkeeping and reporting 

burdens. Without a description of how this record-keeping and reporting will create an additional 

 

9 One of the major manufacturers of wood furniture coatings, Valspar, does not carry any products that have greater 

than 1 percent formaldehyde leading to the conclusion that coatings greater than 1 percent formaldehyde are mostly 

unnecessary in the industry. http://www.valsparwood.com/valsparwood/msds/msds.jsp. Also through conversations 

with facilities, we have not encountered facilities that definitively have more than 1% formaldehyde concentrations 

within their coatings. See Estimated Cost Impact for Wood Furniture Manufacturing Industry to Comply with 

Proposed Formaldehyde Limit on Coating Operations Wood Furniture Manufacturing RTR for information 

regarding formaldehyde concentrations in Kitchen Kompact‘s coatings in the docket for this action.
69

burden and/or a reason why it is not necessary to keep track of emissions information, EPA has 

no reason to modify the provisions.

47. Comment: Commenter 51 stated that the best available science indicates that 

formaldehyde in outdoor air does not present a risk to human health. 

The World Health Organization (WHO) found that ―[i]n ambient air, formaldehyde is quickly 

photo-oxidized in carbon dioxide. It also reacts very quickly with the hydroxyl radicals to give 

formic acid. The half-life estimated for these reactions is about one hour depending on the 

environmental conditions.‖ (WHO, 2010, at 103). Further, WHO concluded that because levels 

in ambient air are low, outdoor air does not contribute significantly to indoor pollution. Id. at 

108. Therefore, EPA‘s proposed cap on formaldehyde use is an unnecessary restriction that will 

not reduce residual risk, if any, to public health.

Response: Everyone is exposed to small amounts of formaldehyde in air and some foods 

and products. Nasal and eye irritation, neurological effects, and increased risk of asthma and/or 

allergy have been observed in humans breathing 0.1 to 0.5 ppm. Eczema and changes in lung 

function have been observed at 0.6 to 1.9 ppm.

The Department of Health and Human Services (DHHS) has determined that formaldehyde is a 

known human carcinogen based on human and animal inhalation studies.10

The EPA considers formaldehyde as a ―Probable Human Carcinogen‖ in IRIS; 

http://www.epa.gov/iris/subst/0419.htm. The International Agency for Research on Cancer 

(IARC) classifies formaldehyde as a human carcinogen; 

http://monographs.iarc.fr/ENG/Monographs/vol88/index.

Ambient modeling of formaldehyde in the National Scale Air Toxics Assessment 

(NATA) at major urban centers indicate that formaldehyde exposures over the long term for 

excess cancer risks could be up to 100 in a million with a national average of 20 in a million 

based upon the current IRIS Unit Risk Estimate (URE). Monitoring at the National Air Toxics 

Trends Sites for formaldehyde are in good agreement with the NATA, refer to the following 

website; http://www.epa.gov/ttn/atw/nata2005/compare.html. 

The dispersion modeling for wood furniture manufacturing and shipbuilding does not 

incorporate photochemical decay. The EPA conducted a sensitivity analysis and determined this 

feature in AERMOD11 does not have a significant effect on near-field exposures and is most 

relevant for population exposures in the far field especially for pollutants with half-lives less than 

30 minutes. The rate of decay is also very dependent temporally with less reactivity occurring 

during evening hours as well as during colder seasons. For more information on the sensitivity 

analysis, please refer to Section 4.6: Sensitivity Analysis – Atmospheric Chemistry in ―the 

EPA‘s Risk and Technology Review (RTR) Risk Assessment Methodologies,‖ that was 

reviewed by the EPA‘s SAB; http://www.epa.gov/ttn/atw/rrisk/rtrpg.html. Based upon the rate of 

decay for formaldehyde varying from 1 hour to 16 hours and the fact that the MIR location for 

 

10 This is according to the Agency for Toxic Substances and Disease Registry. 

http://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=219&tid=39

11AERMOD was developed by the American Meteorological Service (AMS)/EPA Regulatory Model Improvement 

Committee (AERMIC). This is the preferred model by EPA for modeling point, area and volume sources of 

continuous air emissions from facilities.
70

this source category is located within 300 meters of the emission source, we find that 

photochemical decay will not have an effect on the MIR.

Comment: Multiple commenters (39, 49, 51, and 52) offered comments related to the cost 

estimate for meeting the new formaldehyde standard.

Commenter 51 noted that EPA does not adequately support its cost estimate. The commenter 

stated that EPA provided no data or analysis to support its assumption that facility operations are 

the same or that the use of no- or low- formaldehyde coatings and adhesives would be suitable 

for use by all facilities.

Commenter 51 further noted that EPA‘s ―cost analysis‖ consists of price information, from one 

supplier, of thirteen no- or low-formaldehyde coatings that the Agency considers to be suitable 

for use in wood furniture manufacturing operations. See U.S. EPA, Memo: Impacts of 

Implementing a Limit on Formaldehyde Usage in the Wood Furniture Manufacturing Operations 

Source Category (Oct. 19, 2010). The commenter noted that EPA does not analyze whether the 

available coatings can be used in all applications or would meet industry performance standards.

Commenters 39 and 51 noted that EPA does not list any no- or low-formaldehyde contact 

adhesives in its analysis.

Commenter 52 stated that the technical and cost analyses EPA puts forth in support of the 400 

lb/yr limit are not backed up by any critical analysis or actual data. According to the commenter, 

this analysis amounts to the assertion that, ―because some facilities are doing it, all facilities 

should be able to do it. This is an empty  ̳analysis‘ that provides no support for the proposed 400 

lb per year limit. On top of that, EPA also asserts that the new standard can be met  ̳at little or no 

extra cost.‘‖ The commenter stated that a much more robust cost analysis would be needed to 

justify imposing an additional emissions limitation.

Moreover, commenters 49 and 51 noted that EPA does not address the additional costs incurred 

due to the potential need for new equipment, the significant expenses to adapt to a new finish 

material, or costs resulting from an increase in business.

Response: Based on information received in comments, we have adopted a 1 percent by 

weight formaldehyde limit with a 400 pounds formaldehyde per rolling 12-month period

alternative compliance limit that allows wood furniture manufacturers to use their discretion to 

reformulate to lower formaldehyde coatings and contact adhesives while not necessitating the 

expense of production line reconfiguration. As discussed above, we have updated the cost 

effectiveness analysis for the proposed formaldehyde limit and concluded that the 400 pound per 

12 month limit as proposed would not be cost effective12. 

Using low-formaldehyde coatings and contact adhesives reflects developments in 

technology and was described in the proposal as the method to achieve compliance with the 

 

12 For further detail, see memo to the docket, Estimated Cost Impact for Wood Furniture Manufacturing Industry to 

Comply with Proposed Formaldehyde Limit on Coating Operations Wood Furniture Manufacturing RTR, dated July 

15, 2011.
71

proposed 400 pounds formaldehyde per rolling 12-month period. A limit of 1 percent

formaldehyde in coatings and adhesives allows facilities the flexibility to use coatings and 

adhesives that are suitable for a range of different products, from cabinets to home furnishings, 

without compromising their quality, cost, or production.13 Also, in many cases, the 1 percent 

formaldehyde limit will allow flexibility in different types of line configurations.14

Although we did not list any low-formaldehyde contact adhesives in the proposed rule 

making, does not mean they do not exist. 3M‘s Fastbond Contact Adhesive 30NF is an example 

of many that do not contain formaldehyde. 

48. Comment: Commenter 51 stated that EPA has not demonstrated that the formaldehyde cap 

will reduce residual risk. Instead, EPA‘s cap will unnecessarily limit wood furniture production 

and EPA should not adopt the proposed standard.

Commenter 39 agreed that a review of the facility data compiled by EPA fails to show that 

emissions of formaldehyde correspond to a high cancer risk or that a reduction in emissions of 

formaldehyde will result in a reduction of this risk. Of the 385 wood furniture manufacturing 

facilities evaluated by EPA, only 141 facilities emit formaldehyde, and of the 141 formaldehydeemitting facilities, only 26 emit more than EPA‘s proposed threshold of 400 pounds per year. 

Commenter 39 further referenced EPA‘s December 2010 Draft Residual Risk Assessment for the 

Wood Furniture Manufacturing Source Category. Within that memo, 63 facilities were identified 

as having a cancer Maximum Individual Risk (MIR) of greater than 1-in-1 million. Of these 63, 

less than one-third have formaldehyde emissions exceeding the 400 pound per year threshold, 

with only 9 facilities out of the 25 with the highest MIR emitting formaldehyde above the 400 

pounds level, compared to six of the top 25 having no formaldehyde emissions reported. 

Response: EPA is not promulgating the 400 pound/year formaldehyde limit based on risk 

reduction. With this limit now being a compliance alternative to the 1% formulation limit of 

formaldehyde, risk reductions cannot be determined and no quantifiable risk reductions are being 

claimed as a result of either the 400 pound per 12 month limit or the 1% by weight formaldehyde 

content limit. It is the EPA‘s belief that the promulgated formaldehyde limits maintain the same 

level of risk as the existing NESHAP.

C. GLYCOL ETHERS

49. Comment: Multiple commenters (39, 48, and 50) noted that EPA overestimated the health 

risk from glycol ethers by using ethylene glycol methyl ether as the representative glycol ether. 

Given that the use of glycol ethers other than ethylene glycol methyl ether is the norm for the 

industry, the risk associated with this class of compounds is overstated in EPA's analysis and no 

additional regulation of glycol ethers is warranted. Both commenters referred to Table 4 in 

EPA‘s October 22, 2010 memorandum Review of Glycol Ether Emissions Associated with Wood 

 

13 It is necessary for some facilities to minimize levels of formaldehyde in the coating formulation to promote crosslinking nucleation. This process directly affects the quality and durability of the wood furniture. See notes from the 

Marsh Furniture Site Visit in the docket for this action for reference.

14 For additional information, please see memo to the docket, Meeting with Kitchen Cabinet Manufacturers 

Association (KCMA), dated August 17, 2011.
72

Furniture Manufacturing Source Category. The table contains a summary of speciated glycol 

ethers that are less toxic than ethylene glycol methyl ether, resulting in EPA‘s overestimation of 

the health risk from these compounds.

Commenter 39 offered another assessment approach for glycol ethers:

A more reasonable assessment of glycol ethers would be the example based on data 

from all facilities of a large wood furniture manufacturing company. Glycol ether 

emissions in 2010 totaled 3.76 tons, of which over 95% of the emissions were 

ethylene glycol monobutyl ether, with the remainder comprising diethylene glycol 

phenyl ether, diethylene glycol butyl ether and phenoxyethanol. Based on the 

preponderance of ethylene glycol monobutyl ether in these emissions, a risk 

assessment using the significantly higher REL for ethylene glycol monobutyl ether 

(REL = 14 vs. REL for in ethylene glycol methyl ether of 0.093 ref: 

http://www.oehha.ca.gov/air/pdf/acuterel.pdf) would conclude that the risk from 

glycol ethers is approximately 150 times lower than EPA's analysis shows. Even if 

the REL for another glycol ether - Ethylene Glycol Monoethyl Ether, REL 0.37 -

were used, the risk associated with glycol ethers would be reduced by a factor of 4.

Commenter 48 offered another option. The commenter recommended that the HQs derived for 

Propyl Cellosolve® by the EPA be recalculated using the proposed REL for EGPE. The attached 

proposed REL (included in their comment) for EGPE demonstrates that sufficient information 

exists to derive an REL for EGPE, which would be more appropriate for risk management than 

the REL for EGME.

Response: As we acknowledged in the proposal, the use of the EGME REL in our acute 

risk screening assessments provided us with a conservative (i.e., health-protective) estimate of 

potential acute health risks from glycol ethers when the exact speciation profile of emitted glycol 

ethers was uncertain. For this source category, approximately 70 percent of facilities reporting 

glycol ether emissions reported them without any speciation information. Since there are no 

AEGL or ERPG values available for any glycol ethers, this further limits our ability to interpret 

the potential acute impacts of glycol ethers. Since this uncertainty remains, the EPA is not 

convinced that the use of less health-protective assumptions (such as those recommended by the 

commenters) represents any improvement in the assessment of potential acute impacts. Even so, 

because of the health-protective nature of our assessment, we do not believe that these estimated 

worst-case acute glycol ether impacts warrant the adoption of additional control measures.

50. Comment: Commenter 50 stated that the industry meets current Occupational Safety and 

Health Administration (OSHA) regulations on ethylbenzene and glycol ethers emissions in the 

workplace, including curing and gluing operations. Imposition of different regulations by EPA 

would be confusing and possibly contradictory. According to limited data, such emissions are de 

minimis.

On the other hand, commenter 45 asked that a residual risk standard be set for glycol ether 

emissions. California has listed glycol ethers as a toxic air contaminant and EPA should consult 

the California EPA data and reference values for glycol ethers in order to address these 

emissions, and the risk they create.
73

Response: EPA‘s responsibility to protect public health generally does not cover 

occupational exposures within the work place; that is the specific jurisdiction of OSHA, as the 

commenter notes. Under the authority of the Clean Air Act, EPA develops residual risk 

rulemakings to ensure that hazardous air pollutant emissions from plants are at levels that 

provide an ample margin of safety to protect public health under section 112(f). As such, our 

risk assessments are designed to characterize the exposures of the public, not those of industrial 

workers. Ultimately, the regulations of OSHA, which are protective of industrial workers, 

combined with the regulations of EPA, which are protective of public health, work together to 

provide appropriate protection for all. This approach does not create confusion or contradiction 

since the success of each regulatory approach is measured by its ability to provide protection for

a different segment of the population.

With respect to glycol ethers, EPA is aware of glycol ether reference values developed by 

California EPA and has taken them into account in our risk assessments for this rule, as 

appropriate within our stated hierarchy of accepted dose-response values. See the risk assessment 

documentation for further details on this hierarchy and how it is used. Based on the results of 

our risk assessments, the existing Wood Furniture NESHAP was determined to provide an ample 

margin of safety, and no additional regulation was warranted.

D. SPRAY GUNS

51. Comment: Commenter 49 suggested that the EPA either define the term ―conventional‖ or 

mention the types of spray guns that are to be used to assist the regulated community in 

complying with this rule. The commenter suggested specific items, mentioned in the Paint 

Stripping and Miscellaneous Surface Coating Operations rule (Subpart HHHHHH): Highvolume low-pressure(HVLP) spray guns, electrostatic applications, airless or air-assisted airless 

spray guns, or air-assisted airless equivalent technologies.

Commenter 43 suggested that the EPA exclude the following components from the definition:

handheld non-refillable aerosol containers, touch-up markers, marking pens, and the application 

of paper film or plastic film which may be pre-coated with an adhesive by the manufacturer.

These items are allowed by the miscellaneous metal parts and products NESHAP (subpart 

MMMM).

Response: The existing Wood Furniture Manufacturing Operations MACT standards 

define ―conventional air spray‖ as:

―a spray coating method in which the coating is atomized by mixing it with compressed 

air and applied at an air pressure greater than 10 pounds per square inch (gauge) at the 

point of atomization. Airless and air assisted airless spray technologies are not 

conventional air spray because the coating is not atomized by mixing it with compressed 

air. Electrostatic spray technology is also not considered conventional air spray because 

an electrostatic charge is employed to attract the coating to the workpiece.‖ 40 CFR 

63.801(a).
74

Many of the above suggestions for specific coating applications are clearly included or 

excluded by the definition of conventional spray provided in the 1995 NESHAP. The 

technologies listed above such as touch-up markers, marking pens, and manufacturer pre-coated 

adhesive film are not affected by the restriction on use of conventional spray guns because they 

do not have a spray, i.e., they are not ―a spray coating method.‖ Even if certain technologies are 

allowed under other rule makings such as subpart HHHHHH, the commenter did not explain 

why these applications are appropriate for this rule making. Examples of compliant spray 

technology under the Wood Furniture NESHAP include, but are not limited to, HVLP spray 

guns, low-volume low-pressure guns (LVLP), electrostatic applications, airless and air-assisted 

airless spray guns. Low-capacity HVLP cup guns may be used for small batch operations. 

52. Comment: Commenter 49 suggested that EPA clarify in the rule that facilities with 

controls can continue to use conventional spray guns. Any emissions would be controlled via the 

control device.

Commenter 50 noted that several RTOs, which rely on rich VOC waste streams, are being 

operated in the industry. To impose air-assisted-airless guns reduces RTO efficiency and requires 

more fossil fuel to be consumed. 

Response: The proposed rule has been revised to continue to allow use of conventional 

spray guns when the overspray is routed to a functioning control device. The efficiency of the 

control device sufficiently reduces excess emissions associated with the decreased spray 

efficiency of conventional spray guns.15 

53. Comment: Commenters 39 and 50 noted that EPA offered an incorrect premise that all 

applicator improvements to increase transfer efficiency of the sprayed material will result in 

reduced emissions simply due to higher transfer efficiencies. The premise does not consider the 

low-use application considerations required for trials, touchups, and product repairs. 

Commenter 39 noted:

HVLP and equivalent high efficiency applicators require larger volumes of premixed 

materials for application and are best utilized where large quantities of materials are 

intended (usually volumes larger than one gallon to as much as 30 gallons) and in 

production quantity applications where large surface areas are coated. Under large 

volume spray applications, the high transfer efficiency equipment results in reduced 

material consumptions resulting in lower operating costs and lower emissions. Under 

high volume application conditions, there are both economic and environmental 

advantages for operations to use high transfer efficiency equipment. 

 

15 A typical transfer efficiency of an HVLP gun is 65-85 percent compared to 25-45 percent for conventional guns 

under similar conditions. This is a difference of 40 percent spray efficiency. When compared to an estimate of 90 

percent efficiency of a control device, the control device more than compensates for the 40 percent reduction in 

efficiency of guns. For more information on transfer efficiencies of spray technologies see the memo to the docket, 

Impacts of Prohibiting the Use of Conventional Spray Guns in the Wood Furniture Manufacturing Operations 

Source Category, dated October 29, 2010.
75

However, for low use applications such as low volume color stains, trial materials, 

small touchups and repairs, mixing large batches for use in high transfer efficiency 

equipment will result in increased material consumption and waste, increased cleanup 

solvent consumption and waste, and, for catalyzed top coat materials, material loss 

through restricted pot life. The proposed applicator changes would result in an 

inability to properly mix small batch work coatings (stains, sealers, topcoats, etc.), 

resulting in more wasted raw material, increased cleanup material use, waste, and 

emissions and an unnecessary increase in generated waste volume. 

Arguably, the use of low volume conventional spray equipment such as cup guns, 

etc., affords the industry a small volume spray alternative that would otherwise 

require a part to be re-finished or scrapped entirely. Failed finish repairs with minimal 

rework and reapplication to the part and in some instances salvage of an otherwise 

scrapped production part makes production and environmental sense. Indeed small 

quantity applicators (generally those with a restricted volume of 1.0 U.S. quart or 

less) may actually result in lower VOC and VHAP emissions due to the restricted use 

and inherent limited production capability of the application equipment itself. 

Such an overreaching requirement for all spray equipment to be of the HVLP spray 

type or equivalent is not reasonable and does not consider the other adverse 

environmental impacts discussed above. 

Commenter 50 expressed some of the same concerns as Commenter 39.

Response: First we note the commenter agrees with the EPA that with large volume spray 

applications, which the commenter defines as larger than one gallon and in production quantities, 

high transfer efficiency equipment results in reduced material consumption, lower operating 

costs and lower emissions16. In addition, we find that the application technology is available for 

small batches of coating to be applied with non-conventional spray guns such as HVLP cup 

guns. The use of HVLP cup guns will allow for smaller batch mixes. This prevents unneeded 

coating material going to waste. With the higher spray efficiency associated with nonconventional spray guns, a greater portion of the spray is coating the piece of wood. This means 

that there is less overspray leading to fewer emissions. Other touch-up applications such as 

touch-up markers and handheld non-refillable aerosol containers may still be used under the 

standard. For more information see Use of Non-Conventional Spray Technology in the Wood 

Furniture Manufacturing Industry, dated August 3, 2011 and Impacts of Prohibiting the Use of 

Conventional Spray Guns in the Wood Furniture Manufacturing Operations Source Category, 

dated October 19, 2010, in the docket for this action.

54. Comment: Commenter 52 argued that EPA lacks authority to ban conventional spray guns 

in the wood furniture manufacturing source category: 

The proposed rule‘s ban on conventional air spray guns is without rational basis and 

lacks justification under §112(d)(6). The Agency attempts to justify the ban on the 

possibility that conventional air spray guns may be more widely used in the future. To 

the Agency‘s reasoning, a ban would prevent a possible future resurgence in this 

 

16 For more information please see Impacts of Prohibiting the Use of Conventional Spray Guns in the Wood 

Furniture Manufacturing Operations Source Category, dated October 19, 2010, in the docket for this action.
76

technology. However, EPA offers no information justifying their concern about their 

potential for future use, relying instead on the unsupported assertion that it might 

happen. Moreover, EPA refutes even this slim justification by also asserting that 

affected sources will save money by shifting away from conventional technology. In 

short, this proposed rule would be regulation for the sake of regulation. As such, it is 

not a supportable exercise of §112(d)(6) authority.

Response: EPA fully justified the prohibition on use of conventional air spray guns in the 

preamble to the proposed rule as well as a supporting memo, Use of Non-Conventional Spray 

Technology in the Wood Furniture Manufacturing Industry, dated August 3, 2011. We 

explained that conventional air spray guns have lower transfer efficiencies and higher emissions 

than other spray gun types, so requiring use of other spray gun types such as air assisted airless 

would prevent higher emissions resulting from use of conventional air spray guns. Conventional 

air spray is defined at 40 CFR 63.801 as, in short, a spray coating method in which the coating is 

applied at greater than 10 psi, specifically excluding airless, air assisted airless, and electrostatic 

spray technology. While it is generally accurate to describe this provision as a prohibition on use 

of conventional air spray guns (with the remaining exception for use of control devices), it would 

be equally accurate to describe it as a requirement to use spray guns in which the coating is 

applied at 10 psi or less or else that are airless, air assisted airless, or electrostatic. We also 

explained that the cost of discontinuing use of conventional spray guns was believed to be 

minimal, and in fact may result in a net cost savings.

Based on comments received from other commenters, we have made an adjustment to the 

prohibition on conventional air spray guns by preserving the existing exception that allows 

conventional air spray gun use when a control device is used for the emissions, as discussed 

above and in the preamble.

Contrary to Commenter 52‘s assertion, EPA is not required to prove whether conventional air 

spray guns will be more widely used in the future in order to justify greater restrictions on their 

use. EPA‘s prohibition on conventional air spray guns, with an exception for use of control 

devices, is justified under Clean Air Act section 112(d)(6) as a measure to limit HAP emissions, 

with little to no costs (and possibly net savings) for affected sources.

55. Comment: Commenter 43 noted that EPA has assumed, without presenting supporting 

evidence, that conventional spray guns are now ―rarely used.‖ 

We were unable to locate in the Federal Register notice or in the rulemaking record a 

numerical estimate of the number of conventional spray guns (expressed in total 

numbers or as a percentage of all spray guns) that are currently in use. The 

commenter is therefore concerned that EPA‘s figures underestimate the importance of 

conventional spray guns, especially because they are used for specialized, low 

volume application. The commenter believes that EPA should provide more 

information about the current usage of conventional spray guns in the wood furniture 

manufacturing subcategory before taking further steps towards a prohibition.

Second, it appears that EPA has assumed that there are no issues of feasibility with 

the prohibition against conventional spray guns. However, some facilities use guns 
77

that operate above 10 pounds per square inch (psi) for applications where the use of 

lower-pressure guns is not feasible.

Third, the commenter was concerned that EPA has underestimated the useful life of conventional 

spray guns and the replacement cost of such guns. In the analysis of the impacts of prohibiting 

the use of conventional spray guns, EPA assumed that conventional guns have an expected life 

of up to two years. The commenter stated that some companies have reported that the useful life 

of their spray guns easily exceeds five years with routine maintenance practices such as 

replacement of worn packings, nozzles, and fluid needles. Similarly, the commenter believes that 

the average cost of an air-assisted spray gun is higher than EPA‘s estimate of $500.

Response: In the notice of proposed rulemaking, EPA presented its understanding of the 

limited and declining use of conventional spray guns, and the availability of alternatives thereto,

in the wood furniture industry and solicited comment on a proposed ban. The EPA received 

further information regarding the number of conventional spray guns from a few sources within 

the industry.1718 The information from these sources indicates that the vast majority of facilities 

are no longer using any conventional spray guns and of those relatively few that are, about twothirds use them in conjunction with control devices which would continue to be allowed under 

the final rule. Given the information provided, we still believe that the small number of wood 

furniture facilities still using conventional spray guns without control devices are doing so 

mostly for touch-up work and because they did not feel compelled to make a change within a 

working system.

192021In this RTR rulemaking, EPA is adopting a restriction on use of 

conventional spray guns based on our determination that more efficient, lower-emitting spray 

technologies are available and at reasonable cost. Based on the limited number of conventional 

guns currently in use, the EPA believes it is reasonable to expect that conventional guns will be 

replaced after their useful life within the three-year compliance period of the final rule. The few, 

if any, that remain after three years will have very limited useful life left. A commenter asserted 

that  ̳some‘ companies have reported a useful exceeding five years with certain routine 

maintenance practices, but commenter did not provide any specifics as to how many companies 

and spray guns this applies to, whether these facilities or spray guns are unusual, and the costs of 

the routine maintenance practices. Without such information, EPA is not revising its estimated 

useful life of conventional spray guns, except to note that to the extent that any such spray guns 

have a useful life beyond 3 years from the effective date of this rule, they will be few in number 

and very limited in remaining useful life. The EPA also maintains that non-conventional spray 

guns are technically feasible and applicable for touch-up work. See Response to Comment #54

above. The commenter asserts that the cost of an air-assisted spray gun is higher than EPA‘s 

estimate of $500 but failed to identify a different cost figure or provide any supporting 

information, so EPA is not revising its cost estimate for a replacement air-assisted spray gun. 

 

17 An email from Dick Titus of KCMA describing the frequency of conventional spray guns within a sector of the 

industry is in the docket for this action. 

18 An email from Bryan Starnes of Linwood Furniture describing their current use of conventional spray guns is in 

the docket for this action.

19 Please see the Notes from Linwood Furniture Site Visit in the docket for this action for more information.

20 An email from Dick Titus of KCMA describing the frequency of conventional spray guns within a sector of the 

industry is in the docket for this action. 

21 An email from Bryan Starnes of Linwood Furniture describing their current use of conventional spray guns is in 

the docket for this action
78

E. SSM PROVISIONS

56. Comment: Two commenters (43 and 46) voiced concern with EPA‘s proposal to amend 

several Subpart JJ provisions in response to Sierra Club v. EPA, in which the U.S. Court of 

Appeals for the D.C. Circuit vacated two of the MACT general provisions that address SSM 

events. The vacated provisions are 40 CFR 63.6(f)(1) and 63.6(h)(1). Both commenters 

referenced the Kushner Letter, written by Adam Kushner, Director of EPA‘s Office of Civil 

Enforcement.

Commenter 43 noted that Table 1 to Subpart JJ indicates that neither of the vacated provisions 

has been incorporated into Subpart JJ. The commenter cited the Kushner Letter, which explains 

the potential impact of the SSM litigation and provides two lists of Section 112(d) rules. The first 

category identifies MACT standards that will be ―immediately affected‖ by the Court‘s decision 

because the rules specifically incorporate the vacated provisions. The second category lists rules 

that have a source-category specific SSM provision which will not be affected by the Court‘s 

decision. The commenter noted that Subpart JJ is not identified in either list. 

Commenter 43 suggested that it would be more appropriate to address the decision in the 

following ways:

EPA [should] first develop a comprehensive rulemaking response that explains how 

EPA will address the Court‘s vacatur of 40 CFR 63.6(f)(1) and 63.6(h)(1). This 

process would involve a detailed review by EPA of the Court‘s decision and, as 

appropriate, proposed amendments to the MACT general provisions that would 

conform to the outcome of the case. Because the vacated provisions impact several 

different MACT standards, they should be assessed first on a broader scale before any 

changes to the individual source category standards are proposed.

Commenter 46 noted that the Wood Furniture Manufacturing provision was not affected by the 

SSM Decision (Kushner Letter). Commenter 46 also noted:

EPA has previously found a case-by-case basis consideration of potential 

enforcement to be a less desirable route to address malfunctions. 37 Fed. Reg. 17,214, 

17,214 (Aug. 25, 1972). As the Supreme Court has found, ―a reasoned explanation is 

needed for disregarding facts and circumstances that underlay or were engendered by 

the prior policy.‖ FCC v. Fox Television Stations, Inc., 129 S. Ct. 1800, 1811 (2009) 

(citation omitted). EPA failed to provide any explanation as to why it now believes a 

case-by-case affirmative defense is a more appropriate route.

Response: EPA intends to propose a comprehensive rulemaking response to 

address the Court‘s vacatur of 40 CFR 63.6(f)(1) and 63.6(h)(1). Our proposal will be 

comprehensive, in that it will address 63.6(f) and (h), and the related provisions of 63 

Subpart A that address planning, monitoring, recordkeeping, and reporting of emissions 

related to startup, shutdown, and malfunction under the various MACT standards. Further, 

EPA intends to address most of the MACT standards in that proposal to ensure that MACT 

standards conform to the court‘s decision.
79

While EPA is developing this more comprehensive response, EPA was and is 

simultaneously required to meet deadlines on o7ther MACT standards, deadlines imposed 

by the Act itself, consent decrees, court orders, and the like. EPA opted to address the 

court‘s decision on SSM in MACT rules being proposed and promulgated, while still 

developing a more comprehensive proposal, in a good faith effort to put the court‘s 

decision into practice expeditiously.

It is EPA‘s intention to propose that affirmative defense be included in the general 

provisions and make it available to all sources subject to a MACT standard in part 63. 

Thus, the decision to include affirmative defense in actions prior to our comprehensive 

response is intended to be congruent with our action to remove startup, shutdown, and 

malfunction exemptions in those rules. EPA considered it unreasonable to remove startup, 

shutdown, and malfunction exemptions without providing affirmative defense available to 

the sources, when our intention is to provide it in the near future in subsequent action 

applicable to those sources.

F. RULE TEXT CORRECTIONS

57. Comment: Commenter 49 recommended EPA add the following language from other 

MACT standards for consistency and burden reduction: 

A. What Source Categories and Subcategories Are Affected by the Final Rule?

The final rule applies to you if you own or operate a [miscellaneous metal parts and 

products] surface coating facility that is a major source, or is located at a major 

source, or is part of a major source of HAP emissions. We define a [miscellaneous 

metal parts and products surface coating] facility as any facility engaged in the 

surface coating of any [miscellaneous metal part or product]. If application of coating 

to a substrate occurs, then surface coating also includes associated activities, such as 

surface preparation, cleaning, mixing, and storage. However, these associated 

activities do not comprise surface coating if the application of coating does not occur. 

Coating application with handheld, non-refillable aerosol containers, touch-up 

markers, marking pens, or the application of paper film or plastic film which may be 

pre-coated with an adhesive by the manufacturer is not a coating operation for the 

purposes of the final rule. You will not be subject to the final rule if your

[miscellaneous metal parts and products] surface coating facility is located at an area 

source. An area source of HAP is any facility that has the potential to emit HAP but is 

not a major source. You may establish area source status by limiting the source‘s 

potential to emit HAP through appropriate mechanisms available through your 

permitting authority. The final rule does not apply to surface coating or a coating 

operation that meets any of the criteria listed below:

A coating operation conducted at a source where the source uses only 

coatings, thinners and/or other additives, and cleaning materials that contain 

no organic HAP, as determined according to the procedures in the final rule.
80

Surface coating that occurs at research or laboratory facilities, or is part of 

janitorial, building, and facility maintenance operations, or that occurs at 

hobby shops operated for noncommercial purposes.

Coatings used in volumes of less than 189 liters (50 gallons (gal)) per year, 

provided that the total volume of coatings exempt does not exceed 946 liters 

(250 gal) per year at the facility.

B. Determination of Mass Fraction of Organic HAP

(a) Determine the mass fraction of organic HAP for each material used.

You must determine the mass fraction of organic HAP for each coating, thinner, and 

cleaning material used during the compliance period by using one of the options in 

paragraphs (a)(1) through (5) of this section.

(1) Method 311 (appendix A to 40 CFR part 63). You may use Method 311 for 

determining the mass fraction of organic HAP. Use the procedures specified in 

paragraphs (a)(1)(i) and (ii) of this section when performing a Method 311 test.

(i) Count each organic HAP that is measured to be present at 0.1 percent by mass or 

more for Occupational Safety and Health Administration (OSHA)-defined 

carcinogens as specified in 29 CFR 1910.1200(d)(4) and at 1.0 percent by mass or 

more for other organic HAP compounds. For example, if toluene (not an OSHA 

carcinogen) is measured to be 0.5 percent of the material by mass, you do not have to 

count it. Express the mass fraction of each organic HAP you count as a value 

truncated to four places after the decimal point (for example, 0.3791).

(ii) Calculate the total mass fraction of organic HAP in the test material by adding up 

the individual organic HAP mass fractions and truncating the result to three places 

after the decimal point (for example, 0.763).

(2) Method 24 (appendix A to 40 CFR part 60). For coatings, you may use Method 24 

to determine the mass fraction of nonaqueous volatile matter and use that value as a 

substitute for mass fraction of organic HAP.

(3) Alternative method. You may use an alternative test method for determining the 

mass fraction of organic HAP once the Administrator has approved it. You must 

follow the procedure in § 63.7(f) to submit an alternative test method for approval.‖

(4) Information from the supplier or manufacturer of the material. You may rely on 

information other than that generated by the test methods specified in paragraphs 

(a)(1) through (3) of this section, such as manufacturer‘s formulation data, if it 

represents each organic HAP that is present at 0.1 percent by mass or more for OSHA 

defined carcinogens as specified in 29 CFR 1910.1200(d)(4) and at 1.0 percent by 

mass or more for other compounds. For example, if toluene (not an OSHA 

carcinogen) is 0.5 percent of the material by mass, you do not have to count it. For 

reactive adhesives in which some of the HAP react to form solids and are not emitted 

to the atmosphere, you may rely on manufacturer‘s data that expressly states the 

organic HAP or volatile matter mass fraction emitted. If there is a disagreement 

between such information and results of a test conducted according to paragraphs 

(a)(1) through (3) of this section, then the test method results will take precedence 
81

unless, after consultation, you demonstrate to the satisfaction of the enforcement 

agency that the formulation data are correct.

Response: The language recommended by the commenter is unnecessary for the Wood 

Furniture NESHAP or this RTR rulemaking, and the commenter did not provide specific 

reasons to do so, so EPA is not including it.

III. SHIPBUILDING

A. RISK ASSESSMENT

58. Comment: Commenter 45 stated that EPA has failed to fulfill its section 112(f)(2) duty to 

fully assess and determine whether the risk from this source category is ―acceptable.‖ EPA 

concludes that this category creates an MIR of 20-in-1 million based on allowable emissions, and 

10-in-1 million based on estimated ―actual‖ emissions. EPA does not justify its conclusion on the 

record that this level of risk is acceptable. It simply lists the numbers and different factors, 

without explaining how it is analyzing these factors or why they have led EPA to reach its 

conclusion. EPA recognizes that disparities in risk exist, with individuals in certain demographic 

groups, including African Americans and people with income below the poverty level, more 

likely to experience a higher level of risk. As discussed above, EPA cannot simply rely on the 

old Benzene presumption that any level of risk under 100-in-1 million is acceptable. And, the 

fact that 4,000 people is a ―relatively low‖ number (i.e., the number estimated to be exposed to 

cancer risks of 1-in-1 million or greater) does not justify EPA‘s proposal of inaction to protect 

these people. Section 112(f)(2) requires EPA to set standards for the maximum exposed 

individual. The individuals in this group of 4,000 are the very people whom the law requires 

EPA to be concerned about.

Response: We do not consider the 1-in-1 million MIR level as a  ̳bright line‘ mandated 

level of protection for establishing residual risk standards. In determining the ample margin of 

safety (i.e., the level of the standard), health risk is one factor that we must consider, along with 

other factors such as cost and technological feasibility. Balancing these and other factors with the 

ability to achieve meaningful risk reduction is a critical component of the residual risk 

rulemaking process. We considered reducing risks further but concluded that the technology 

required, such as a portable or permanent enclosure big enough to accommodate an entire ship or 

even a section of a ship to capture and control air emissions, would be cost prohibitive for this 

industry. Although our additional analysis of the demographics of the exposed population shows 

some disparities in risks between demographic groups for both categories, the EPA has 

determined that no group is exposed to an unacceptable level of risk. In general, the contribution 

of the source category to elevated facilitywide cancer or noncancer risks is low throughout the 

facilities in this source category. The primary processes driving the facilitywide cancer and 

noncancer risks are welding and abrasive blasting which are not regulated under this source 

category.

Comment: Commenter 45 stated that EPA has determined that maximum individual 

cancer risk at the facility-wide level is 200-in-1 million based on estimated ―actual‖ emissions. 

This means that the risk is likely to be higher based on allowable emissions. (allowable up to 2 

times greater than estimated ―actual‖). The allowable level is the level of maximum individual 
82

exposure. Further, of the 41 facilities with facility-wide MIR of 1-in-1 million or more, 15 have 

shipbuilding and ship repair operations that contribute over 50 percent to the facility-wide risks. 

Yet, EPA does not propose to take any action to address that risk. EPA should investigate ways 

to reduce this residual risk. It does not consider or address whether this level of facility-wide risk 

is acceptable at facilities where this source category is contributing so significantly. EPA must 

do so to complete its section 112(f)(2) duty. Its failure to consider regulatory options to address 

this residual risk is also arbitrary and capricious. At minimum, EPA should consider whether to 

set a residual risk standard in order to reduce this high level of facility-wide risk. It should 

consider requiring extra work practice, reporting, monitoring, and other measures for facilities 

that have the level of emissions putting them into this highest risk category. In sum, EPA must 

address what standard is needed ―to provide maximum feasible protection against risks to health‖ 

by ―protecting the greatest number of persons possible‖ to a lifetime risk level no greater than 1-

in-1 million. (quoting Benzene NESHAP), and its facility-wide risk analysis has failed to 

complete this essential step.

Response: We examined facilitywide risk to provide additional context to the source 

category risks. Facilitywide risks are driven by estimated emissions from abrasive blasting and 

welding sources at Shipbuilding and Ship Repair facilities. These sources are not part of the 

Shipbuilding and Ship Repair (surface coating) source category. As discussed in the preamble to 

the proposed actions for this source category [75 FR 80237], we intend to list welding and 

abrasive blasting operations as a major source category under section 112(c)(5) of the CAA.

59. Comment: Commenter 45 stated that EPA has identified that some of the high cancer risk

from these facilities is driven by hexavalent chromium emissions from welding and abrasive 

blasting operations. It also has found that the high TOSHI is driven by manganese from these 

operations. Commenters support EPA‘s proposal to list welding and abrasive blasting operations 

as a source under section 112(c)(5), 42 U.S.C. § 7412(c)(5), to address these significant amounts 

of HAP emissions. The commenter urged EPA to do so promptly now that it has information 

showing that it is necessary to list this source category. The commenter also noted that California 

has developed a child reference dose value for manganese that EPA should consult in developing 

regulations for this new source category(See 

http://www.oehha.ca.gov/public_info/public/kids/schools070306.html; and 

http://www.oehha.ca.gov/public_info/public/kids/pdf/Mn-PCPFinal-070306.pdf.).

Response: EPA intends to list welding and abrasive blasting operations that occur at 

shipbuilding and ship repair facilities as a major source category under Section 112(c)(5) of the 

CAA. EPA may consider the use of CAL-EPA‘s child RfD values for ingestion risks, only for 

those pollutants that meet EPA‘s criteria as a PBT. A review of the methodology from EPA‘s 

Air Toxics Risk Assessment Reference Library; Appendix D: ―Methodology for Identifying PBHAP Compounds,‖ Table 1 did not identify manganese as a PB-HAP; 

http://www.epa.gov/ttn/fera/data/risk/vol_1/appendix_d.pdf. A review of criteria utilized by 

EPA to assess persistence, bioacculmulative, and toxicity indicate that manganese does not 

readily bioaccumulate in the environment and is most toxic thru the inhalation pathway.

60. Comment: Commenter 53 provided support for the Agency‘s proposal to re-adopt the 

existing provisions of the Shipbuilding and Ship Repair (Surface Coating) NESHAPs (40 CFR 

Part 63 Subpart II) have been effective in providing an ample margin of safety to protect public 
83

health and prevent adverse environmental effects, as determined by the Agency‘s risk and 

technology review.

The commenter (53) also expressed support for the Agency‘s proposal to re-adopt the existing 

provisions of the Shipbuilding and Ship Repair (Surface Coating) NESHAP for the purpose of 

meeting the requirements of Section 112(f)(2) of the Clean Air Act and Amendments.

The commenter stated that they continue their research and development activities to improve 

their portfolio of coatings used in the global shipbuilding and ship repair industry. Among these 

products are improved anti-fouling and foul-release technologies, and sealers/tie coats to enable 

their effective use. The commenter‘s R&D programs also target reductions of VOC and VOHAP 

contents of their marine and protective coating products to meet the sustainability expectations.

Response: We appreciate the commenter‘s support on our approach to evaluating residual 

risk for the shipbuilding and ship repair source category. 

61. Comment: Commenter 42 stated that with respect to the Shipbuilding and Ship Repair 

standard, we are concerned that EPA based its decision that no additional controls are needed 

and that the existing standard provides an ample margin of safety in part due to ―the uncertainty 

and lack of data associated with one potential risk reduction option identified, and the 

technological infeasibility of the other option identified‖. The commenter urged EPA to obtain 

the necessary data regarding the two options to make a more informed decision, including 

contacting air quality agencies that currently regulate the source category. We compliment EPA 

on its intention to list welding and abrasive blasting operations at shipbuilding and ship repair 

facilities as a major source category under section 112(c)(5), but encourage EPA to determine 

the extent to which this action will address the risks remaining at these facilities before deciding 

that relying on this strategy is sufficient.

Commenter 45 stated that EPA‘s proposal fails to satisfy the ―ample margin‖ requirement. EPA 

bases this conclusion in part on the fact that it has ―not identified any data regarding the 

availability, use, performance, and emissions associated with the use of lower overall VOHAP 

content or lower toxicity VOHAP content.‖ Id. EPA‘s conclusion is incorrect based on the use of 

the California standards in place. It is unclear why EPA did not simply contact the four identified 

California air quality districts that have more stringent emission limits to attempt to gather these 

data. See Part IV.A.1, infra. This is the 8-year residual risk rulemaking and now is the time to 

collect and consider those data. EPA may not defer or ignore this responsibility, or the fact that 

stricter standards are in use that it must address. EPA also cannot justify a failure to set a residual 

risk standard on a lack of data. EPA has failed to explain how the existing section 112(d) 

standard could provide the required ―ample margin of safety.‖ Commenter 45 also stated that

standards in other jurisdictions are more stringent than the existing MACT. For shipbuilding and 

ship repair, EPA has recognized that four California air quality districts have implemented 

stronger standards. Where other jurisdictions have implemented stronger standards this provides 

evidence that for the purposes of CAA § 112(d)(6) more stringent limitations are achievable and 

have been achieved.

However, for the shipbuilding and ship repair category, EPA states that there are differences 

between coating limits in the four air districts, and that the 1995 MACT standard includes cold 
84

weather limits which are not present in the California standards due to its moderate climate. 

Neither of these points is a valid reason for EPA not to further analyze and adopt stronger 

standards based on these California examples. While it may not be appropriate to adopt the 

California standards in full on a national basis, EPA gives no rational justification for not 

analyzing how to take these models and use them to create an appropriate national standard 

under CAA § 112(d)(6). EPA concludes that ―we do not have data to determine whether these

lower-VOC content coatings could be applied nationwide.‖ Gathering and analyzing that data, 

starting with any information already compiled by the California districts, is precisely what the 

section 112(d)(6) rulemaking is designed for. A lack of data is not a lawful basis for EPA to 

decline to adopt a stronger MACT standard.

Response: The EPA researched current technologies for the shipbuilding and ship repair 

surface coating industry, and did not find any cost effective options that would make the current 

standard more stringent. Related to the marine coating limits in the MACT rule, we reviewed the 

general use and 22 specialty coating VOHAP limits and the lower limits that some states and air 

districts have adopted over the past decade for some of the specialty categories. Furthermore, we 

requested comment on the availability and feasibility of using lower VOHAP coatings but did 

not receive any data or information during the comment period. Following proposal, we did 

contact a shipyard in Maine, and found that the use of lower VOHAP coatings, such as those 

required to meet the limits set by some of the California air quality districts, is not feasible in 

climates that are not as moderate and, therefore, necessitate greater thinning of paint.

As noted by the commenter, some jurisdictions have implemented more stringent 

standards that have resulted in changes to formulations being used in those locations. However, 

temperature and humidity issues experienced by other locations would make painting operations 

having to comply with the more stringent limitations more difficult, more expensive, and in some 

cases unachievable. 

There are many different coatings, and in some cases groups of specific coatings, 

comprising each of the marine coating categories. Over the past several years, there have been 

changes to some formulations with HAP solvent reductions and solvent replacements, but those 

are coating and manufacturer specific and not reflective of the entire marine coating category.22

B. WELDING AND ABRASIVE BLASTING

62. Comment: Commenter 54 stated that the National Shipbuilding Research Program (NSRP) 

was created by U.S. shipyards at the Navy‘s request to reduce the cost of building and 

maintaining U.S. Navy warships. NSRP is a collaboration of several major U.S. shipyards 

focused on industry-wide implementation of solutions to common cost drivers. The program 

targets solutions to consensus priority issues identified by the Navy shipbuilding community and 

industry by undertaking R&D efforts that exhibit a compelling business case to increase warship 

affordability by improving U.S. shipbuilding and ship repair efficiency. The NSRP is comprised 

 

22 See following memos to the docket on cost effectiveness of control technologies: Cost Analyses for Add-on 

Controls for Surface Coating Operations at Shipbuilding and Ship Repair Facilities, dated September 2, 2010 and 

Affordability of Add-on Controls for Shipbuilding and Ship Repair Source Category, dated October 18, 2010.
85

of ten ―Ship Production Panels,‖ one of which is the Environmental Technology Panel (ETP), 

which focuses on environmental compliance issues as they relate to the shipbuilding/repair 

industry and its customers.

The U.S.EPA published an Advance Notice of Proposed Rulemaking (ANPRM), entitled ―Risk 

and Technology Review, Phase II, Group 2‖ in the Federal Register on March 29, 2007 (72 Fed. 

Reg. 14734). The ANPRM stated that entities potentially affected by this action include facilities 

containing any one or more of the 22 major source categories subject to the 12 National 

Emission Standards for Hazardous Air Pollutants (NESHAP), commonly referred to as 

Maximum Achievable Control Technology (MACT) standards. ―Shipbuilding and Ship Repair 

Operations‖, North American Industry Classification System (NAICS) code 336611, and MACT 

code 0715, was included in this as a source category (U.S. EPA, 2007).

The commenter recognized the potential impact that this proposed ruling could have on the 

shipbuilding industry, and took a proactive approach to work with the U.S. EPA in a 

collaborative effort to support the development of a final rule. Early in this process, the U.S.EPA 

and the NSRP ETP recognized that this approach would be mutually beneficial in supporting 

both the U.S. EPA‘s mission to ensure that human health and the environment are protected from 

potentially hazardous air pollutants with an ample margin of safety, as well as the commenter‘s 

goal to ensure that any regulatory decisions made in support of the U.S. EPA‘s mission would be 

based on scientifically defensible data, and not default conservative assumptions.

In response to the ANPRM published in 2007, the commenter submitted a series of comments 

expressing concern that the use of the proposed conservative default values and assumptions 

associated with such things as HAP emissions, metal speciation, facility air emissions modeling, 

and health risk calculations to fill identified data gaps would overestimate the actual risk from 

shipyard welding operations. Since submitting those comments, the NSRP ETP has worked 

towards improving the data available to the U.S. EPA to reduce the need for default values and 

assumptions. The commenter did this by completing several research projects primarily focused 

on collecting actual welding emissions data. The NSRP ETP worked closely with Mr. Tom 

Driscoll from U.S. EPA‘s Measurement and Policy Group, to coordinate U.S. EPA reviews of 

sampling and analysis plans used to guide these research projects. The purpose of this was to: (1) 

Address any comments and/or concerns that the U.S. EPA may have with the scientific approach 

developed to collect and analyze weld fume samples prior to completing the project; and (2) 

Ensure that the resulting data would be of a level of quality that could be accepted by the 

U.S.EPA for use in the rulemaking process. Upon completion of each research project, the 

commenter provided Mr. Driscoll with a Final Summary Report, which documented the research 

activities and provided the final data. The commenter‘s intent was for this data to be used in later 

stages of the residual risk process, and ultimately be reflected in the Proposed Rule.

However, when the Proposed Rule was published in the Federal Register, Vol.75, No. 244, on 

December 21, 2010, it stated that, ―...this MACT standard only includes the surface coating 

operations that occur at these facilities during shipbuilding and ship repair...‖ (p. 80235); and 

―We therefore intend to list welding and abrasive blasting operations that occur at shipbuilding 

and ship repair facilities as a major source category under Section 112(c)(5) of the CAA. We 

request additional information on the HAP emitted by these activities. Once we have this 

information, we will be in a better position to identify the appropriate scope of the major source 
86

category to be listed‖ (p. 80237).‖ In response to this request, the commenter prepared this data 

package to be officially submitted to the docket for consideration in the potential development of 

any future major source category that may be developed for or may include shipyard welding 

operations.

The intent of this letter is to summarize how the data generated from the commenter‘s past 

efforts can be used to support the potential development of a new major source category, and to 

explain why shipyard welding operations differ greatly from other manufacturing processes that 

use welding heavily in their processes to the point that a uniform approach to regulation of 

shipyard welding with other, heavier welding operations may not be possible.

Summary of commenter efforts:

1. Submitted June 28, 2007 - Response to Comments on the March 29, 2007 ANPRM (72 Fed. 

Reg. 14734):

The commenter prepared and submitted comments to the Air and Radiation Docket (EPA-HQOAR-2006-0859) on June 28, 2007. The commenter believes that these comments are applicable 

to the potential development of a major source category for shipyard welding operations, and are 

requesting that they be reviewed and considered if such a category is developed (provided as 

Appendix A of this letter).

2. Completed July, 2008 - Control Technology Demonstration and Weld Fume Evaluation

(CTC, 2008a):

Under this project, it was determined that actual welding process and material usage data would 

be critical to verifying current weld fume emissions. As such, the team researched and selected 

the most commonly used process/electrode combinations, and evaluated the fume generation 

rates, and the concentration of hazardous air pollutants emitted to characterize weld fume 

emissions. The differing welding processes and electrode types were selected by researching 

actual industry usage data. One survey based on data from 12 reporting shipyards (Serageldin, 

January 2005) found that the most common shipyard welding processes are Flux Cored Arc 

Welding (FCAW) (55% of the welding) and Shielded Metal Arc Welding (SMAW) (29%). This 

same study found that 90% of rods are mild steel (including 71T and 7018), and that only 1% 

stainless steels are used.

Another study which had 16 reporting shipyards (Harris, 2000) found that the welding processes 

used are 64% FCAW, 14% Gas Metal Arc Welding (GMAW) and 10% SMAW. This study 

found that the most common rods/wires used with SMAW are E7018, E6010/E601 1, E11018; 

the most common for FCAW is E71-T1; and the most common for GMAW are ER70S-3, 

ER100S-1, and ER120S-1. They also found that 85% of shipyard welding is on mild steels. A 

survey of five shipyards participating as active members of this project team was conducted 

during October 2007 to determine the quantity and types of electrodes that they used during a 

recent one-year timeframe. For these shipyards, 77% of the welding was FCAW, 15% was 

SMAW, 7% was GMAW and 1% was GTAW. Less than 1% of the welding was done using 

stainless steel electrodes.
87

In these shipyards, 99% of the FCAW welding is done with electrodes 71T-1C and 81T1; 85% 

of SMAW welding is done with 7018 electrodes; and 85% of GMAW welding is done with 

E70C-6M electrodes. Based on these studies, it is seen that FCAW, SMAW and GMAW are the 

three welding processes used most frequently in the shipyards; thus, these were the processes 

selected for this project. The most commonly used electrodes were selected for use with these 

processes and included the stainless steel electrodes E309, E310, and E316, along with the 

carbon steel electrodes E7018, E71T, E81T1, and E70C-6M.

After addressing comments and recommendations provided by the U.S. EPA‘s Measuring and 

Policy Group on the project Sampling and Analysis Plan, testing was completed at two 

shipyards, and the data was evaluated independently for each testing event. The fume generation 

rates for these process/electrode combinations were calculated using the average of 5 separate 

welding runs, completed in a specially modified American Welding Society (AWS) welding 

fume chamber. The total fume generated was collected in filters and analyzed through 

gravimetric analysis. The Total Metals: Chromium (Cr), Hexavalent Chromium (CrVI), 

Manganese (Mn), Nickel (Ni), and Lead (Pb), emissions factors were the result of a single 

sample. The samples were collected on glass or quartz fiber filters in the modified AWS fume 

chamber, and were analyzed according to Occupational Safety and Health Administration 

(OSHA) or National Institute of Occupational Safety and Health (NIOSH) methods.

The emissions factors for Total Chromium were higher for the stainless steel electrodes (SMAW 

309L, 310-16, FCAW 309L, and 316L) than for the carbon steel electrodes. Total Cr emissions 

factors ranged from 92 to 551 μg/g of electrode consumed for the stainless steel electrodes, but 

was less than 5 μg/g for the carbon steel electrodes. The lowest chromium emissions factor for a 

stainless steel electrode was generated by the GMAW process. As for Cr(VI), emissions factors 

were again higher for the stainless steel electrodes than for the carbon steel electrodes. Cr(VI) 

emissions factors ranged from 5 to 375 μg/g for the stainless steel electrodes, and were 2 μg/g or 

lower for the carbon steel electrodes. The lowest Cr(VI) emissions factor for a stainless steel 

electrode was generated by the GMAW process. The ratio of Cr(VI) to Cr was only calculated 

for the stainless steel electrodes because the amount of Cr and Cr(VI) in the carbon steel 

electrodes was low, and in some cases was below limits of detection. For the three processes, 

using four electrodes, Cr(VI) accounted for ~5% to ~86% of the total chromium, which varied by 

process; again with the GMAW process having the lowest value, followed by FCAW, then 

finally SMAW with the highest. Emissions factors for total nickel were also highest for the 

stainless steel electrodes, ranging from 29 to 229 μg/g, while the carbon steel electrodes ranged 

from 0.3 to 4 μg/g. Manganese emissions factors ranged from 79 to 925 μg/g and were 

consistently high for all process/electrode combinations that were evaluated. Total lead 

emissions factors were low for all process/electrode combinations, ranging from less than 0.2 to 

4.7 μg/g. It should be noted again here that these values are the result of two independent 

samples, collected for each process/electrode combination, at two different shipyards.

The single point emissions factors were then compared to emissions factors values published in 

the U.S. EPA‘s, ―AP-42, Fifth Edition, Compilation of Air Pollutant Emissions Factors, and 

Volume 1: Stationary Point and Area Sources, January 1995‖ (AP-42), and the ―Shipbuilding 

and Ship repair – Residual Risk, Proposed Emissions Factors for Stainless Steels, Mild Steels, 

and Alloys Steels, Presented during their July 26, 2005 Conference Call (as the data used for 

stainless steels and mild steels) (Residual Risk Proposed)‖. For Total Cr, Cr(VI), Mn, and Ni, the 
88

calculated emissions factors for the stainless steel electrodes evaluated were generally consistent 

(either slightly above or below), or a great deal less than the published values. For SMAW 309L, 

total Cr, Mn and Ni were all less than the Residual Risk Proposed emissions factors, while there 

are no SMAW 309L factors provided in AP-42 for comparison. However, Cr(VI) was found to 

be higher than the Residual Risk Proposed emissions factors. For SMAW 310-16, Cr, Cr(VI), 

and Mn are all significantly less than the AP-42 published emissions factors, but were found to 

be generally consistent for Pb. These were all found to be generally consistent with the Residual 

Risk Proposed emissions factors. For FCAW 309L, total Cr, Mn and Ni were all a great deal less 

than the Residual Risk proposed emissions factors, while Cr(VI) appeared to be consistent. There 

were no FCAW309 factors provided in AP-42 for comparison. For GMAW316L, the emissions 

factors measured in this study were generally a great deal less than those published in the AP-42 

and in the Residual Risk proposed emissions factors for Cr, Cr(VI), Mn, and Ni. For all of the 

process/electrode combinations evaluated, the emissions factors for Pb were a great deal less 

(ranging from <0.2 to 3 μg/g) than the default value of 215 μg/g provided for all of the selected 

process/electrode combinations in Residual Risk proposed values. With the four carbon steel 

electrodes evaluated, the emissions factors determined for Cr, Cr(VI), Ni and Pb were generally 

consistent with or less than, the AP-42 and the Residual Risk proposed values. With regard to 

Mn, the measured emissions factors for SMAW 7018M were approximately half of the AP-42 

and the Residual Risk proposed values. For GMAW70C-6M, the emissions factors calculated 

under this project were approximately twice the values for those listed under 70S in AP-42 and 

the Residual Risk proposed emissions factors (70C-6M was not listed in either of these 

documents). For the remaining two electrodes, FCAW71T-1C and FCAW81T1, the Mn values 

measured in this project were consistent with the published values.

Also as part of this project, the NSRP ETP demonstrated and evaluated two, commercially 

available, portable welding emissions control technologies. The objective of this testing was to 

determine the capture (ability to capture the fume at the source) and control (filters‘ ability to 

remove the contaminant from the exhaust air) efficiency of both units. The first technology 

tested was a low vacuum, high volume portable system designed for medium duty extraction and 

filtration of welding fumes. The capture efficiency ranged from ~73% to ~100% over the various 

runs, with an average of 95%.

A total of 20 samples were collected from the exhaust air stream of the unit, three (3) produced a 

detectable concentration of Mn, two (2) produced a detectable concentration of Ni, while all 20 

produced results below the limit of detection for Cr, Cr(VI), and Pb. Shipyard welders 

commented that this type of unit would work best for fixed-site welding operations and would 

not be as suitable for long, linear welds, and not at all be suitable for using on-board a vessel due 

to its size. The second unit demonstrated was a smaller, more portable, high vacuum, low 

volume unit, with two different extraction attachments, a bell-shaped nozzle, and a fume 

extraction gun. The capture efficiency with the bell-shaped nozzle ranged from ~42% to ~89% 

with an average of 60%. The fume gun was determined to be ineffective for use in a shipyard 

environment. When the air velocity was set to a high enough velocity to capture the weld fume, 

the shielding gas was pulled away from the point of the weld, resulting in a poor quality weld. A 

total of 24 samples were collected from the exhaust air stream of the unit; one (1) produced a 

detectable concentration of Mn, and one (1) produced a detectable concentration of Ni, while all 

24 produced results below the limit of detection for Cr, Cr(VI), and Pb.
89

The general conclusion that were reached as a result of this research project were: 

Based on industry research, the primary welding process used by the shipbuilding and 

ship repair industry is FCAW, followed by SMAW and GMAW. This is significant 

because the analytical data generated in this project demonstrated that FCAW and 

GMAW generally produce fewer emissions as compared to SMAW.

Based on industry research the majority (~85 to 99%) of shipyard welding is completed 

using mild steel as opposed to stainless steel. This is significant because the analytical 

data generated in this project demonstrated mild steel generally produces fewer Cr(VI) 

emissions as compared to stainless steel. This is an important fact, considering the Cr(VI) 

is a known human carcinogen and the primary risk driver for estimated offsite cancer 

risks.

Several discrepancies were found between the emissions factors generated under this 

project, and the Proposed Residual Risk emissions factors; most notably for Pb, Cr, Mn. 

It is requested that the data used to develop the Proposed Residual Risk emissions factors 

be evaluated for accuracy and applicability for use in the development of shipyard 

emissions factors as we strongly believe that the introduction of specifically developed 

factors will enhance the ability to accurately characterize emissions for any potential 

welding rulemakings.

The capture and control efficiency of the control technologies was demonstrated, and 

their limitations were discussed. However, a full scale assessment of their applicably for 

use in a shipyard environment was not completed. Due to the unique nature of 

shipbuilding and ship repair activities, it is recommended that a technology assessment be 

completed to determine if control technologies could be implemented at a reasonable 

cost.

3. July 29, 2008 - Evaluation of Welding Electrodes to Determine the Mass Fraction and Decay 

Rate of Hexavalent Chromium:

Under this project the team selected three commonly used welding process/electrode 

combinations, SMAW 310-16, FCAW 309 and FCAW 71T-1. The 310 and 309 electrodes are 

both stainless steel, while the 71T-1 is mild steel. Even though shipyards perform much more 

welding on mild steels than on stainless steels, two of the three electrodes chosen were stainless 

steel because their higher chromium content made them more representative of ―worst case‖ risk 

conditions for Cr(VI) emissions. These process/electrode combinations were evaluated for fume 

generation rates and concentrations of hazardous air pollutants using the same procedure as 

referenced under the first project. However the testing under this project was completed in a high 

bay testing facility as opposed to a shipyard, and three (3) data points were collected for each 

process/electrode combination as opposed to one (1), which were then averaged to generate the 

emissions factors. As with the first research project, the mild steel electrode FCAW 71T-1 

produced fewer Cr(VI) emissions at 0.08 μg/g, as compared to the two stainless steel electrodes, 

FCAW 309 and SMAW 310-19, which produced Cr(VI) emissions at 31.4 and 388 μg/g, 

respectively. The ratio of Cr(VI) to Cr varied based on the various welding process/electrode 

combinations. The fume generated from the SMAW 310-16 electrode contained the greatest ratio 
90

of Cr(VI) to Cr at 72%, followed by FCAW 309 at 25% and FCAW 71T-1 at 3%. As discussed 

under the first project, the metal-specific emissions factors were compared to the AP-42 and the 

Proposed Residual Risk emissions factors. When comparing the SMAW 310-16 developed 

emissions factors to the Proposed Residual Risk emissions factors, they are generally consistent. 

However, when they are compared to the factors listed in the AP-42, with a quality rating of C, 

the developed emissions factors are a great deal lower for Cr(VI), Cr, and Mn, and are consistent 

for Ni. The developed emissions factors for FCAW 309 are a great deal less for Cr, Mn, and Ni,

and are generally consistent for Cr(VI). There were no AP-42 values available for FCAW 309 

for comparison. For FCAW 71T-1, the developed emissions factors are generally consistent with 

the Proposed Residual Risk emissions factors as well as with the AP-42 listed values, with the 

exception of Ni, in which case the developed emissions factor is a great deal less that the 

Proposed Residual Risk emissions factors.

The decay rate testing was completed on fume collected from the SMAW 310-16 electrode by 

allowing the sample to set out on untreated filters, exposed to ambient conditions in a laboratory 

environment (temperature ~70 °F, relative humidity of 50%) for specified time intervals of 3, 6, 

9, 12, 15, 18, 24, and 48 hours after sampling. At the designated time interval the sample was 

placed in a buffer solution to inhibit the conversion of Cr(VI) to Cr. A decay rate constant of 

0.012 was calculated for Cr(VI) in SMAW 310-16 weld fume. The data from this study 

demonstrated that 25% of the initial Cr(VI) decayed within 24 hours and about 44% of the initial 

Cr(VI) decayed within 48 hours. The Cr(VI) half-life was estimated to be approximately 58 

hours.

The general conclusions that were reached as a result of this research project were:

Mild steel, which is the steel primarily used in shipbuilding welding processes, generally 

produces fewer Cr(VI) emissions as compared to stainless steel. This is an important fact, 

considering the Cr(VI) is a known human carcinogen and the primary risk driver for 

estimating offsite cancer risks.

Based on the data obtained, it appears that FCAW generally produces fewer Cr(VI) 

emissions (0.08 and 31.4 μg/g) as compared to SMAW (388 μg/g). This is significant 

considering that FCAW is used to a greater extent as compared to SMAW.

Several discrepancies were found between the emissions factors generated under this 

project, and the Proposed Residual Risk emissions factors, and those published in the AP42. Most notably for SMAW 310-16, and FCAW 309. It is requested that the data used to 

develop the Proposed Residual Risk emissions factors be evaluated regarding its accuracy 

and applicability for use in the development of emissions factors.

There is documented evidence that the concentration of Cr(VI) reduces over time as it 

transforms into Cr(III). This is significant because it demonstrates that not all of the 

Cr(VI) generated during shipyard welding will reach the fence line due to its natural 

conversion to Cr(III). Based on this, the risk to public health will decrease as the distance 

from the point of origin increases, based on the fact that the amount of time that the 

Cr(VI) is present in the environment increases as well.
91

It is requested that the natural decay of Cr(VI) in the environment be taken into account in any 

future regulatory decision.

4. December 30, 2009 - Developing Emissions Factors for Electrodes Commonly used within 

the Shipbuilding Industry for use in Regulatory Reporting Procedures:

The third project expanded on the work completed under the previous two projects. The same 

procedure was used to collect and analyze the weld fumes while simulating typical shipyard 

processes, but the number of samples collected for each process/electrode combination was 

increased to six (6) as opposed to three (3), to increase the scientific defensibility of the results. 

An alternate approach was used to select five welding process/electrode combinations for 

evaluation. The selection was based on: overall volume of use in the shipyards; lack of current 

high quality emissions factors listed in the AP-42; and, the composition of Cr(VI) and Mn as the 

primary constituents that drive the estimation of shipyard offsite public health risks. The 

process/electrodes selected for evaluation were as follows: FCAW 308, FCAW 309, SMAW 

11018, SMAW 309 and SMAW 7018. The average (mean of 12) total fume emissions factors for 

the two stainless steel FCAW electrodes, 308LT1 and 309LT1, were 5.5 and 6.27 mg/g, 

respectively.

The average total fume emissions factor for the stainless steel SMAW electrode, 309L-16, was 

10.4 mg/g. The total fume emissions factors for the two mild steel SMAW electrodes, 7018M 

and 11018-M, were 20.5 and 17.3 mg/g, respectively. For the metals Cr, Pb, Mn, and Ni, the 

reported emissions factors represent the average of six data points. The average Cr emissions 

factors for the two stainless steel FCAW electrodes, 308LT-1 and 309LT1, were 426 and 696 

μg/g, respectively, and for the stainless steel SMAW electrode, 309L-16, the average was 716 

μg/g. The average Cr emissions factor for the carbon steel SMAW electrode 7018M was 6 μg/g. 

As expected, these values are lower than those for the stainless steel electrodes. The average 

Cr(VI) emissions factors for the two stainless FCAW electrodes, 308LT-1 and 309LT1, were 12 

and 37 μg/g, respectively, and for the stainless steel SMAW electrode, 309L-16, the average was 

252 μg/g. The average Cr(VI) emissions factor for the carbon steel SMAW electrode, 7018M 

was 1.2 μg/g. It should be pointed out that the Cr(VI) emissions factor of 71 +/- 35 μg/g for the 

SMAW11018-M electrode is statistically higher than the Cr emission factor of 21 +/- 3 μg/g. It is 

not possible to obtain a Cr(VI) value higher than the total Cr value. 

The project team investigated several potential sources for this discrepancy in the data, but a 

definite cause for this could not be determined. The project team suspected that the Cr(VI) value 

is incorrect, due to the fact that it is a mild steel electrode, and would be expected to emit low 

amounts of Cr(VI). However, because this could not be confirmed, the project team 

recommended that both the Cr(VI) and Cr values be disregarded for the SMAW11018-M 

electrode. The Cr(VI)/Cr emissions factor ratio for the two stainless steel FCAW electrodes, 

308LT-1 and 309LT1, were 3 and 5%, respectively, and for the stainless steel SMAW electrode, 

309L-16, it was 35%. The average Pb emissions factors for all of the electrodes ranged from 0.8 

to 3.3 μg/g. The average Mn emissions factors for the two stainless steel FCAW electrodes, 

308LT-1 and 309LT1, were 440 and 416 μg/g, respectively, and for the stainless steel SMAW 

electrode, 309L-16, it was 736 μg/g.
92

The average Mn emissions factors for the two carbon steel stick (SMAW) electrodes, 7018M and 

11018-M, were 771 and 1004 μg/g, respectively. The average Ni emissions factors for the two 

stainless steel FCAW electrodes, 308LT-1 and 309LT1, were 56 and 131 μg/g, respectively, and 

for the stainless steel SMAW electrode, 309L-16, it was 64 μg/g. The average Ni emissions 

factors for the two carbon steel stick (SMAW) electrodes, 7018M and 11018-M, were 1 and 46 

μg/g, respectively. This controlled study, which proceeded following a review of the approach by 

the EPA, and all corresponding data help to conclude that this is an appreciable reduction for 

emissions of these potential HAPs (which are risk driving constituents) when compared to the 

speciation ratios used in the rulemaking process. The analysis specifically concluded that the 

CrVI speciation is much closer to the 5% demonstrated in the study when contrasted to the 33% 

speciation offered as a default factor in the rule. We believe that the continued use of any default 

values for the speciation of CrVI at 33% would be unlikely.

Moreover, the continued use of default speciation assumptions for the assessment of CrVI 

emissions would adversely affect the conclusions of any regulatory decisions when those 

decisions are based on assumed speciation when given the findings from this actual testing. The 

welding material supplier ESAB provided comparative testing, using the same electrodes

evaluated under this project, but collected and analyzed the fume in a different manner. It was 

determined that the two methods resulted in comparable data, within one order of magnitude. It 

is important to note that the ESAB data was generated from the analysis of one composite 

sample, while this study is representing the average of the analysis of six individual samples. In 

addition, ESAB used different techniques for sample preparation and analysis.

The emissions factors developed under this study were then compared to those developed under 

those previous two projects, as well as to the AP-42, and to the Proposed Residual Risk 

emissions factors. It should be noted that not all electrodes were included in all of the research 

projects, and not all of the evaluated electrodes and metal species were included in AP-42 or the 

Proposed Residual Risk emissions factors. Based on the electrodes that were able to be 

compared, the following observations were made:

The emissions factors generated in the various studies represented in these comparisons 

are consistent from study to study (within the same order of magnitude) for all metals.

The ratio of Cr(VI) to Cr varied significantly between the FCAW (3% and 5% Cr(VI)) 

and SMAW (21% and 35% Cr(VI)) processes.

The Residual Risk Proposed Cr emissions factor of 3000 μg/g for both FCAW electrodes 

appears to be high relative to the data generated in all of the various studies.

The Residual Risk Proposed Pb emissions factor of 215 μg/g for all stainless steel 

electrodes appears to be high relative to the data generated in the various studies.

The Residual Risk Proposed emissions factors for Cr(VI), Mn, and Ni appear to be 

consistent (within the same order of magnitude) with the emissions factors generated in 

these studies.
93

The general conclusions that were reached as a result of this research project and the collection 

of actual data were:

Mild steel generally produces fewer Cr(VI) emissions as compared to stainless steel. This 

is an important fact, considering the Cr(VI) is a known human carcinogen and the 

primary risk driver for offsite cancer risks.

Based on the data obtained, it appears that FCAW generally produces fewer Cr(VI) 

emissions (0.08 and 31.4 μg/g) as compared to SMAW (388 μg/g). This is significant 

considering that the FCAW is used to a greater extent as compared to SMAW.

Several discrepancies were found between the emissions factors generated under this 

project, and the Proposed Residual Risk emissions factors, and those published in the AP42; most notably for Cr and Pb emissions factors. It is requested that the data used to 

develop the Proposed Residual Risk emissions factors be evaluated regarding its accuracy 

and applicability for use in the development of emissions factors.

This project focused on electrodes that currently did not have published high quality 

emissions factors. It is recommended that these emissions factors be considered for use in 

filling these data gaps.

The commenter worked closely with the U.S. EPA through the coordination of Mr. Tom Driscoll 

of U.S. EPA‘s Measurement and Policy Group during the collection of this data. Most recently, 

the commenter participated in a meeting with U.S. EPA representatives at RTP, NC on January 

19th, 2011. The presentation given by the commenter was provided as an attachment. As a result 

of this meeting, the commenter took the action to prepare and submit these comments to support 

the U.S. EPA in any potential regulatory action taken to address welding as a major source 

category. The commenter was also requested to participate in a project with the U.S. EPA in the 

submission of the emissions factors generated under these projects to ―WebFIRE‖, which will be 

rolled out as a result of the U.S. EPA Emissions Factors Improvement Program. The commenter 

requested that if any future regulatory actions are taken to address welding as a major source 

category, that this be coordinated with the appropriate points of contact from the U.S. EPA‘s 

Emissions Factor Program to ensure consistency and defensibility of the data being used.

Response: The EPA thanks the commenter for this information. The information and 

data provided by the commenter will be reviewed and considered during the development of the 

future MACT for welding and abrasive blasting operations.

63. Comment: Commenter 52 determined that a new source category for welding and abrasive 

blasting operations is unreasonable because such operations are already part of an existing source 

category. In the proposed rule, EPA announced its intent to list welding and abrasive blasting 

operations that occur at shipbuilding and ship repair facilities as a major source category under § 

112(c)(5). The possibility of creating a new source category appears to be based at least in part 

on the facility wide risk assessment, which purports to show significantly higher risk than from 

surface coating operations alone. The additional risk is tied to chromium emissions from welding 

and blasting. 
94

In comments on the October 21, 2010 RTR proposal, the commenter explained that once EPA 

establishes a MACT standard for a particular source category, the Agency has the authority 

under § 112(d)(6) to ―review and revise as necessary (taking into account developments in 

practices, processes, and control technologies), emissions standards promulgated under this 

section no less often than every 8 years.‖ In other words, EPA does not have unfettered 

discretion to revisit a prior MACT determination once that determination has been issued. 

Rather, EPA may revise a prior determination only ―as necessary‖ according to explicit statutory 

criteria. These comments were directed at EPA‘s proposal to adopt new emissions standards 

under §§ 112(d)(2) and (3) for specified ―significant emission sources within the [subject] 

categories for which standards were not previously developed.‖ 

Whereas, in the October 2010 RTR proposal, EPA proposed to ―gap fill‖ existing standards by 

invoking §§ 112(d)(2) and (3), in the case of the current RTR proposal EPA attempts to 

accomplish the same ―gap filling‖ by an alternate route – i.e., by purporting to identify a new 

source category within shipbuilding facilities (welding and abrasive blasting operations) and 

adopting a separate MACT standard for the new source category. This approach to ―gap filling‖ 

is unjustified and in contravention to § 112(d)(6).

The MACT standard for shipbuilding and ship repair operations is applicable to ―shipbuilding 

and ship repair operations at any facility that is a major source.‖ While welding and abrasive 

blasting are included in the defined source category, the current MACT standard does not 

include any emissions limitations or control requirements applicable to these activities. The 

preamble to the proposed standard explains why: 

Over 99 percent of HAP emissions at shipyards are organic solvents associated with 

paints and cleaning. Other activities that collectively contribute the remaining 1 

percent include welding, metal forming/cutting, and abrasive blasting. The proposed 

standards will affect operations involving the use of paint and organic solvents.

Thus, it is clear that EPA included welding and abrasive blasting in the shipbuilding and ship 

repair source category, but chose not to regulate emissions from these activities under the MACT 

standard because the emissions from these activities represented only a very small fraction of 

total HAP emissions from the source category. 

With this context, the assertion in the RTR proposal that a new source category needs to be 

created to regulate HAP emissions from welding and abrasive blasting operations at shipbuilding 

and ship repair facilities is unfounded. Since these activities are already within the defined 

source category, § 112(d)(6) provides the only authority for EPA to adopt § 112(d) standards for 

these activities.

Response: We disagree with the commenter‘s assertion that EPA included welding and 

abrasive blasting in the shipbuilding and ship repair (surface coating) source category. The listed 

source category only addresses surface coating operations at shipbuilding and ship repair 

facilities. As noted previously, we examined facilitywide risk to provide additional context to 

the source category risks. For this source category, the emissions from welding and abrasive 

blasting were concerned in the context of facilitywide risk. The EPA believes that welding and 
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abrasive blasting will be a source category that is relevant to multiple industries, and is therefore 

more appropriate to address outside of just the shipyard and ship repair source category. 

C. ENVIRONMENTAL JUSTICE

64. Comment: Commenter 45 stated EPA recognizes that there are ―disparities in risks‖ for 

certain minority and lower-income individuals. For shipbuilding and ship repair, African 

Americans and people below the poverty level face a cancer risk of at least 1-in-1 million at a 

higher rate than their representation in the population. EPA must consider potential ways to 

address the disproportionate impact on minority individuals and communities in deciding 

whether the likelihood of cancer risk is ―acceptable‖ and whether there is action that could 

provide an ―ample margin of safety‖ for these individuals and communities. Indeed, EPA has 

recognized this since the Benzene NESHAP although it has failed to take action to address this. 

(citing Benzene NESHAP factors, including ―overall incidence of cancer or other serious health 

effects within the exposed population. . . other quantified or unquantified health effects‖). These 

additional factors are supposed to be used in addition to the MIR. It is neither acceptable nor just 

to avoid the need to reduce the correlation between race or income level and a disproportionate 

risk of cancer from toxic air pollution. EPA‘s proposals for inaction, in the face of the recognized 

disparities, contradict the Administrator‘s professed commitment to ―fair treatment‖ (EJ 

Guidance, infra note 30, at 3). With the knowledge it has, EPA must, at minimum, consider the 

amount of background pollution faced by, and baseline health of, racial minorities and 

communities affected by these two source categories, including for the types of health effects 

that these HAP emissions have potential to exacerbate. These types of health data are readily 

available for EPA to factor into its analysis and to use in proposing a regulatory response to the 

disproportionate risk found. It would be arbitrary and capricious to propose to take no further 

action at all after finding these disparities for both source categories.

The commenter supports the EPA‘s effort to gather demographic data. Merely looking at these 

numbers in a simplistic manner, however, is no substitute for a true environmental justice 

analysis. EPA should develop and undertake an actual analysis of the location and community 

effects of these source categories. It has sufficient data on the locations of these facilities to 

undertake an analysis of the effect of their emissions on the maximum exposed individual, the 

history of pollution faced in the most affected community, and to consider how to set a just 

standard in view of these lasting harms.

Response: The demographic analysis found that African-Americans and people below 

the poverty line may be somewhat disproportionately impacted by facilitywide air toxics 

emissions; however, emissions from the source category itself contribute minimally to these 

impacts. The EPA also found the overall level of risk from both source categories to be 

acceptable and to provide an ample margin of safety for all populations in close proximity to 

these sources. As noted previously, the EPA‘s ability to quantitatively assess impacts on 

environmental justice communities is evolving.