[Federal Register Volume 73, Number 242 (Tuesday, December 16, 2008)]
[Rules and Regulations]
[Pages 76220-76230]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-29789]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 63
[EPA-HQ-OAR-2007-0211; FRL-8752-5]
RIN 2060-AO16
National Emission Standards for Hazardous Air Pollutant
Emissions: Group I Polymers and Resins (Polysulfide Rubber Production,
Ethylene Propylene Rubber Production, Butyl Rubber Production, Neoprene
Production); National Emission Standards for Hazardous Air Pollutants
for Epoxy Resins Production and Non-Nylon Polyamides Production;
National Emission Standards for Hazardous Air Pollutants for Source
Categories: Generic Maximum Achievable Control Technology Standards
(Acetal Resins Production and Hydrogen Fluoride Production) (Risk and
Technology Review)
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: This final rule responds to public comments received on the
proposed rule and announces our decision not to revise four national
emission standards for hazardous air pollutants that regulate eight
industrial source categories evaluated in our risk and technology
review. The four national emission standards and eight industrial
source categories are: National Emissions Standards for Hazardous Air
Pollutant Emissions: Group I Polymers and Resins (Polysulfide Rubber
Production, Ethylene Propylene Rubber Production, Butyl Rubber
Production, and Neoprene Rubber Production); National Emission
Standards for Hazardous Air Pollutants for Epoxy Resins Production and
Non-nylon Polyamides Production; National Emission Standards for
Hazardous Air Pollutants for Acetal Resins Production and National
Emission Standards for Hazardous Air Pollutants for Hydrogen Fluoride
Production. The underlying national emission standards that were
reviewed in this action limit and control hazardous air pollutants.
On December 12, 2007, we proposed not to revise the national
emission standards based on our residual risk assessment and technology
review. After conducting risk and technology reviews, and after
considering public comments on the proposed rule, we conclude no
additional control requirements are warranted under section 112(f)(2)
or 112(d)(6) of the Clean Air Act at this time.
DATES: This final action is effective on December 16, 2008.
ADDRESSES: We have established a docket for this action under Docket ID
No. EPA-HQ-OAR-2007-0211. All documents in the docket are listed on the
www.regulations.gov Web site. Although listed in the index, some
information is not publicly available, e.g., confidential business
information or other information whose disclosure is restricted by
statute. Certain other material, such as copyrighted material, is not
placed on the Internet and will be publicly available only in hard copy
form. Publicly available docket materials are available either
electronically through www.regulations.gov or in hard copy at the EPA
Docket Center, Docket ID No. EPA-HQ-OAR-2007-0211, EPA West Building,
Room 3334, 1301 Constitution Avenue, NW., Washington, DC. The Public
Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through
Friday, excluding legal holidays. The telephone number for the Public
Reading Room is (202) 566-1744, and the telephone number for the EPA
Docket Center is (202) 566-1742.
FOR FURTHER INFORMATION CONTACT: For questions about this final action,
contact Ms. Mary Tom Kissell, Office of Air Quality Planning and
Standards, Sector Policies and Programs Division, Coatings and
Chemicals Group (E143-01), U.S. Environmental Protection Agency,
Research Triangle Park, NC 27711; telephone number: (919) 541-4516; fax
number: (919) 685-3219; and e-mail address: [email protected]. For
specific information regarding the modeling methodology, contact Ms.
Elaine Manning, Office of Air Quality Planning and Standards, Health
and Environmental Impacts Division, Sector Based Assessment Group
(C539-02), U.S. Environmental Protection Agency, Research Triangle
Park, NC 27711; telephone number: (919) 541-5499; fax number: (919)
541-0840; and e-mail address: [email protected]. For information
about the applicability of these four national emission standards for
hazardous air pollutants (NESHAP) to a particular entity, contact the
appropriate person listed in Table 1 to this preamble.
[[Page 76221]]
Table 1--List of EPA Contacts for Group I Polymers and Resins, Group II
Polymers and Resins, Acetal Resins Production, and Hydrogen Fluoride
Production
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NESHAP for: OECA contact \1\ OAQPS contact \2\
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Polymers and Resins, Group I Scott Throwe (202) David Markwordt
564-7013 (919) 541-0837
[email protected] markwordt.
v. [email protected].
Polymers and Resins, Group Scott Throwe (202) Randy McDonald (919)
II. 564-7013 541-5402 Mcdonald.
[email protected] [email protected].
v.
Acetal Resins Production.... Marcia Mia (202) 564- David Markwordt
7042 (919) 541-0837
[email protected]. [email protected].
Hydrogen Fluoride Production Marcia Mia (202) 564- Bill Neuffer (919)
7042 541-5435
[email protected]. [email protected].
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\1\ OECA stands for the EPA's Office of Enforcement and Compliance
Assurance.
\2\ OAQPS stands for EPA's Office of Air Quality Planning and Standards.
SUPPLEMENTARY INFORMATION: Regulated Entities. The eight regulated
industrial source categories that are the subject of this final action
are listed in Table 2 to this preamble.
Table 2--Eight Industrial Source Categories
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Category NAICS \1\ code MACT \2\ code
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Butyl Rubber Production................. 325212 1307
Ethylene-Propylene Rubber Production.... 325212 1313
Polysulfide Rubber Production........... 325212 1332
Neoprene Production..................... 325212 1320
Epoxy Resins Production................. 325211 1312
Non-nylon Polyamides Production......... 325211 1322
Acetal Resins Production................ 325211 1301
Hydrogen Fluoride Production............ 325120 1409
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\1\ North American Industry Classification System.
\2\ Maximum Achievable Control Technology.
Table 2 is not intended to be exhaustive, but rather provides a
guide for readers regarding entities likely to be affected by the final
action for the source categories listed. To determine whether your
facility would be affected, you should examine the applicability
criteria in the appropriate NESHAP. If you have any questions regarding
the applicability of any of these NESHAP, please contact the
appropriate person listed in Table 1 of this preamble in the preceding
FOR FURTHER INFORMATION CONTACT section.
Worldwide Web (WWW). In addition to being available in the docket,
an electronic copy of this final action will also be available on the
WWW through the Technology Transfer Network (TTN). Following signature,
a copy of the final action will be posted on the TTN's policy and
guidance page for newly proposed and promulgated rules at the following
address: http://www.epa.gov/ttn/oarpg/. The TTN provides information
and technology exchange in various areas of air pollution control.
Judicial Review. Under section 307(b)(1) of the Clean Air Act
(CAA), judicial review of this final action is available only by filing
a petition for review in the United States Court of Appeals for the
District of Columbia Circuit within 60 days of publication of this
action in the Federal Register, i.e., by February 17, 2009. Under
section 307(b)(2) of the CAA, the requirements established by this
final action may not be challenged separately in any civil or criminal
proceedings brought by EPA to enforce the requirements.
Section 307(d)(7)(B) of the CAA further provides that ``[o]nly an
objection to a rule or procedure which was raised with reasonable
specificity during the period for public comment (including any public
hearing) may be raised during judicial review.'' This section also
provides that EPA shall convene a proceeding for reconsideration,
``[i]f the person raising an objection can demonstrate to the
Administrator that it was impracticable to raise such objection within
[the period for public comment] or if the grounds for such objection
arose after the period for public comment (but within the time
specified for judicial review) and if such objection is of central
relevance to the outcome of the rule.'' Any person seeking to make such
a demonstration should submit a Petition for Reconsideration to the
Office of the Administrator, U.S. EPA, Room 3000, Ariel Rios Building,
1200 Pennsylvania Ave., NW., Washington, DC 20460, with a copy to both
the person(s) listed in the preceding FOR FURTHER INFORMATION CONTACT
section, and the Associate General Counsel for the Air and Radiation
Law Office, Office of General Counsel (Mail Code 2344A), U.S. EPA, 1200
Pennsylvania Ave., NW., Washington, DC 20460.
Outline. The information presented in this preamble is organized as
follows:
I. Background
A. What is the statutory authority for this action?
B. Overview of the Four NESHAP
C. What was the proposed action?
D. What are the conclusions of the residual risk assessment?
E. What are the conclusions of the technology review?
II. Summary of Comments and Responses
A. Emissions Data
B. Risk Assessment Methodology
III. Risk and Technology Review Final Decision
IV. Statutory and Executive Order Reviews
A. Executive Order 12866, Regulatory Planning and Review
B. Paperwork Reduction Act
C. Regulatory Flexibility Act
D. Unfunded Mandates Reform Act
E. Executive Order 13132, Federalism
F. Executive Order 13175, Consultation and Coordination With
Indian Tribal Governments
G. Executive Order 13045, Protection of Children From
Environmental Health Risks and Safety Risks
[[Page 76222]]
H. Executive Order 13211, Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
I. National Technology Transfer and Advancement Act
J. Executive Order 12898, Federal Actions to Address
Environmental Justice in Minority Populations and Low-Income
Populations
I. Background
A. What is the statutory authority for this action?
Section 112 of the CAA establishes a two-stage regulatory process
to address emissions of hazardous air pollutants (HAP) from stationary
sources. In the first stage, after EPA has identified categories of
sources emitting one or more of the HAP listed in section 112(b) of the
CAA, section 112(d) of the CAA calls for us to promulgate NESHAP for
those sources. ``Major sources'' are those that emit or have the
potential to emit any single HAP at a rate of 10 tons or more per year
of a single HAP or 25 tons per year of any combination of HAP. For
major sources, these technology-based standards must reflect the
maximum degree of emission reductions of HAP achievable (after
considering cost, energy requirements, and non-air quality health and
environmental impacts) and are commonly referred to as maximum
achievable control technology (MACT) standards.
The MACT ``floor'' is the minimum control level allowed for MACT
standards promulgated under CAA section 112(d)(3). For new sources, the
MACT floor cannot be less stringent than the emission control that is
achieved in practice by the best-controlled similar source. The MACT
standards for existing sources can be less stringent than standards for
new sources, but they cannot be less stringent than the average
emission limitation achieved by the best-performing 12 percent of
existing sources in the category or subcategory (or the best-performing
five sources for categories or subcategories with fewer than 30
sources). In developing MACT standards, we must also consider control
options that are more stringent than the floor. We may establish
standards more stringent than the floor based on the consideration of
the cost of achieving the emissions reductions, any non-air quality
health and environmental impacts, and energy requirements.
EPA is then required to review these technology-based standards and
to revise them ``as necessary (taking into account developments in
practices, processes, and control technologies)'' no less frequently
than every 8 years, under CAA section 112(d)(6). In this final rule, we
are publishing the results of our 8-year technology review for the
eight industrial source categories listed in Table 3, which we have
collectively termed ``Group 1.''
The second stage in standard-setting focuses on reducing any
remaining ``residual'' risk according to CAA section 112(f). This
provision requires, first, that EPA prepare a Report to Congress
discussing (among other things) methods of calculating risk posed (or
potentially posed) by sources after implementation of the MACT
standards, the public health significance of those risks, the means and
costs of controlling them, actual health effects to persons in
proximity of emitting sources, and recommendations as to legislation
regarding such remaining risk. EPA prepared and submitted this report
(Residual Risk Report to Congress, EPA-453/R-99-001) in March 1999.
Congress did not act in response to the report, thereby triggering
EPA's obligation under CAA section 112(f)(2) to analyze and address
residual risk.
CAA section 112(f)(2) requires us to determine for source
categories subject to certain CAA section 112(d) standards whether the
emissions limitations provide an ample margin of safety to protect
public health. If the MACT standards for HAP ``classified as a known,
probable, or possible human carcinogen do not reduce lifetime excess
cancer risks to the individual most exposed to emissions from a source
in the category or subcategory to less than 1-in-1 million,'' EPA must
promulgate residual risk standards for the source category (or
subcategory) as necessary to provide an ample margin of safety to
protect public health. In doing so, EPA may adopt standards equal to
existing MACT standards (NRDC v. EPA, No. 07-1053, slip op. at 11,
District of Columbia Circuit, decided June 6, 2008). EPA must also
adopt more stringent standards, if necessary, to prevent an adverse
environmental effect,\1\ but must consider cost, energy, safety, and
other relevant factors in doing so. Section 112(f)(2) of the CAA
expressly preserves our use of a two-step process for developing
standards to address any residual risk and our interpretation of
``ample margin of safety'' developed in the 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 (Benzene NESHAP)
(54 FR 38044, September 14, 1989).
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\1\ ``Adverse environmental effect'' is defined in CAA section
112(a)(7) as any significant and widespread adverse effect, which
may reasonably be anticiipated, to wildlife, aquatic life, or other
natural resources, including adverse impacts on populations of
endangered or threatened species or significant degradation of
environmental quality over broad areas.
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The first step in this process is the determination of acceptable
risk. The second step provides for an ample margin of safety to protect
public health, which is the level at which the standards are set
(unless a more stringent standard is required to prevent, taking into
consideration costs, energy, safety, and other relevant factors, an
adverse environmental effect).
The terms ``individual most exposed,'' ``acceptable level,'' and
``ample margin of safety'' are not specifically defined in the CAA.
However, CAA section 112(f)(2)(B) directs us to use the interpretation
set out in the Benzene NESHAP. See also, A Legislative History of the
Clean Air Act Amendments of 1990, volume 1, p. 877 (Senate debate on
Conference Report). We notified Congress in the Residual Risk Report to
Congress that we intended to use the Benzene NESHAP approach in making
CAA section 112(f) residual risk determinations (EPA-453/R-99-001, p.
ES-11).
In the Benzene NESHAP, we stated as an overall objective:
* * * in protecting public health with an ample margin of safety, we
strive to provide maximum feasible protection against risks to
health from hazardous air pollutants by (1) protecting the greatest
number of persons possible to an individual lifetime risk level no
higher than approximately 1-in-1 million; and (2) limiting to no
higher than approximately 1-in-10 thousand [i.e. , 100-in-1 million]
the estimated risk that a person living near a facility would have
if he or she were exposed to the maximum pollutant concentrations
for 70 years.
The Agency also stated that, ``The EPA also considers incidence (the
number of persons estimated to suffer cancer or other serious health
effects as a result of exposure to a pollutant) to be an important
measure of the health risk to the exposed population. Incidence
measures the extent of health risk to the exposed population as a
whole, by providing an estimate of the occurrence of cancer or other
serious health effects in the exposed population.'' The Agency went on
to conclude that ``estimated incidence would be weighed along with
other health risk information in judging acceptability.'' As explained
more fully in our Residual Risk Report to Congress, EPA does not define
``rigid line[s] of acceptability,'' but considers rather broad
objectives to be weighed with a
[[Page 76223]]
series of other health measures and factors (EPA-453/R-99-001, p. ES-
11). The determination of what represents an ``acceptable'' risk is
based on a judgment of ``what risks are acceptable in the world in
which we live'' (Residual Risk Report to Congress, p. 178, quoting the
Vinyl Chloride decision at 824 F.2d 1165) recognizing that our world is
not risk-free.
In the Benzene NESHAP, we stated that ``EPA will generally presume
that if the risk to [the maximum exposed] individual is no higher than
approximately 1-in-10 thousand, that risk level is considered
acceptable.'' 54 FR at 38045. We discussed the maximum individual
lifetime cancer risk (MIR) as being ``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.'' Id. We explained that this
measure of risk ``is an estimate of the upperbound of risk based on
conservative assumptions, such as continuous exposure for 24 hours per
day for 70 years.'' Id. We acknowledge that MIR ``does not necessarily
reflect the true risk, but displays a conservative risk level which is
an upperbound that is unlikely to be exceeded.'' Id.
Understanding that there are both benefits and limitations to using
MIR as a metric for determining acceptability, we acknowledged in the
1989 Benzene NESHAP that ``consideration of maximum individual risk * *
* must take into account the strengths and weaknesses of this measure
of risk.'' Id. Consequently, the presumptive risk level of 100-in-1
million (1-in-10 thousand) provides a benchmark for judging the
acceptability of MIR, but does not constitute a rigid line for making
that determination.
The Agency also explained in the 1989 Benzene NESHAP the following:
``In establishing a presumption for MIR, rather than rigid line for
acceptability, the Agency intends to weigh it with a series of other
health measures and factors. These include the overall incidence of
cancer or other serious health effects within the exposed population,
the numbers of persons exposed within each individual lifetime risk
range and associated incidence within, typically, a 50 kilometer (km)
exposure radius around facilities, the science policy assumptions and
estimation uncertainties associated with the risk measures, weight of
the scientific evidence for human health effects, other quantified or
unquantified health effects, effects due to co-location of facilities,
and co-emission of pollutants.'' Id.
In some cases, these health measures and factors taken together may
provide a more realistic description of the magnitude of risk in the
exposed population than that provided by MIR alone.
As explained in the Benzene NESHAP, ``[e]ven though the risks
judged ``acceptable'' by EPA in the first step of the Vinyl Chloride
inquiry are already low, the second step of the inquiry, determining an
``ample margin of safety,'' again includes consideration of all of the
health factors, and whether to reduce the risks even further. In the
second step, EPA strives to provide protection to the greatest number
of persons possible to an individual lifetime risk level no higher than
approximately 1-in-1 million. In the ample margin decision, the Agency
again considers all of the health risk and other health information
considered in the first step. Beyond that information, additional
factors relating to the appropriate level of control will also be
considered, including costs and economic impacts of controls,
technological feasibility, uncertainties, and any other relevant
factors. Considering all of these factors, the Agency will establish
the standard at a level that provides an ample margin of safety to
protect the public health, as required by section 112.'' 54 FR 38046.
B. Overview of the Four NESHAP
The eight industrial source categories and four NESHAP that are the
subject of this action are listed in Table 3 to this preamble. The
NESHAP limit and control HAP that are known or suspected to cause
cancer or have other serious human health or environmental effects. The
NESHAP for these eight source categories generally required
implementation of technologies such as steam strippers and
incineration.
Table 3--List of National Emission Standards for Hazardous Air Pollutants (NESHAP) and Industrial Source
Categories Affected by This Final Action
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Promulgated rule
Source categories reference and code
Title of NESHAP affected by this of federal Compliance NESHAP as referred
final action regulations date to in this preamble
citation
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NESHAP for Group I Polymers and Polysulfide Rubber 61 FR 46905 (09/05/ 07/31/1997 Polymers and Resins
Resins \1\. Production. 1996). I.
Ethylene Propylene 40 CFR part 63,
Rubber Production. subpart U.
Butyl Rubber
Production.
Neoprene Production
NESHAP for Epoxy Resins Epoxy Resins 60 FR 12670 (03/08/ 03/03/1998 Polymers and Resins
Production and Non-nylon Production. 1995). II.
Polyamides Production. Non-nylon 40 CFR part 63,
Polyamides subpart SS.
Production.
NESHAP for GMACT \2\............. Acetal Resins 64 FR 34853 (06/29/ 06/29/2002 GMACT.
Production. 1999).
Hydrogen Fluoride 40 CFR part 63,
Production. subparts TT, UU,
WW, and YY .
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\1\ The Polymers and Resins I NESHAP regulates nine source categories. We performed the residual risk and
technology review (RTR) for four of them for this action. We will address the remaining five source categories
in a separate RTR rulemaking.
\2\ The source categories subject to the standards in the generic maximum achievable control technology (GMACT)
NESHAP are Acetal Resins Production and Hydrogen Fluoride Production.
1. Polymers and Resins I
The Polymers and Resins I NESHAP regulates HAP emissions from major
sources in nine source categories. In this action, we address four of
the Polymer and Resins I sources categories--Polysulfide Rubber
Production, Ethylene Propylene Rubber Production, Butyl Rubber
Production, and Neoprene Production. The other five source categories
are addressed in RTR Group 2A (73 FR 60432, October 10, 2008). HAP
emissions from these processes can be released from storage tanks,
process vents, equipment leaks, and wastewater operations.
a. Polysulfide Rubber Production. Polysulfide rubber is a synthetic
rubber
[[Page 76224]]
produced by the reaction of sodium sulfide and p-dichlorobenzene (1,4-
dichlorobenzene) at an elevated temperature in a polar solvent.
Polysulfide rubber is resilient, resistant to solvents, and has low
temperature flexibility, facilitating its use in seals, caulks,
automotive parts, rubber molds for casting sculpture, and other
products.
b. Ethylene Propylene Rubber Production. Ethylene propylene
elastomer is an elastomer prepared from ethylene and propylene
monomers. Common uses for these elastomers include radiator and heater
hoses, weather stripping, door and window seals for cars, construction
plastics blending, wire and cable insulation and jackets, and single-
ply roofing membranes.
c. Butyl Rubber Production. Butyl rubber is comprised of copolymers
of isobutylene and isoprene and is very impermeable to common gases and
resists oxidation. A specialty group of butyl rubbers are halogenated
butyl rubbers, which are produced commercially by dissolving butyl
rubber in hydrocarbon solvent and contacting the solution with gaseous
or liquid elemental halogens such as chlorine or bromine. Halogenated
butyl rubber resists aging to a higher degree than the nonhalogenated
type and is more compatible with other types of rubber. Uses for butyl
rubber include tires, tubes, and tire products; automotive mechanical
goods; adhesives, caulks, and sealants; and pharmaceutical uses.
d. Neoprene Production. Neoprene is a polymer of chloroprene.
Neoprene was originally developed as an oil-resistant substitute for
natural rubber, and its properties allow its use in a wide variety of
applications, including wetsuits, gaskets and seals, hoses and tubing,
plumbing fixtures, adhesives, and other products.
2. Polymers and Resins II
The Polymers and Resins II NESHAP regulates HAP emissions from
major sources in two source categories--epoxy resins and non-nylon
polyamides production. In this action, we address both of the Polymer
and Resins II sources categories--Epoxy Resins Production and Non-nylon
Polyamides Production. HAP emissions from these source categories can
be released from storage tanks, process vents, equipment leaks, and
wastewater operations.
a. Epoxy Resins Production. The Epoxy Resins Production source
category involves the manufacture of basic liquid epoxy resins used in
the production of glues, adhesives, plastic parts, and surface
coatings. This source category does not include specialty or modified
epoxy resins.
b. Non-Nylon Polyamides Production. The Non-Nylon Polyamides
Production source category involves the manufacture of epichlorohydrin
cross-linked non-nylon polyamides used primarily by the paper industry
as an additive to paper products. Natural polymers, such as those
contained in paper products, have little cross-linking, which allows
their fibers to change position or separate completely when in contact
with water. The addition of epichlorohydrin cross-linked non-nylon
polyamides to these polymers causes the formation of a stable polymeric
web among the natural fibers. Because the polymeric web holds the
fibers in place even in the presence of water, epichlorohydrin cross-
linked non-nylon polyamides are also referred to as wet-strength
resins.
3. GMACT--Acetal Resins Production
The GMACT set national emission standards for certain source
categories consisting of five or fewer facilities. The basic purpose of
the GMACT approach was to use public and private sector resources
efficiently, and to promote regulatory consistency and predictability
in the MACT standards development.
Acetal resins are characterized by the use of formaldehyde in the
polymerization process to manufacture homopolymers or copolymers of
alternating oxymethylene units. Acetal resins, also known as
polyoxymethylenes, polyacetals, or aldehyde resins, are a type of
plastic possessing relatively high strength and rigidity without being
brittle. They have good frictional properties and are resistant to
moisture, heat, fatigue, and solvents. Acetal resins are used as parts
in a variety of industrial applications, e.g., gears, bearings,
bushings, and various other moving parts in appliances and machines,
and in a range of consumer products, e.g., automotive door handles,
seat belt components, plumbing fixtures, shaver cartridges, zippers,
and gas tank caps.
4. GMACT--Hydrogen Fluoride Production
The Hydrogen Fluoride Production source category includes any
facility engaged in the production and recovery of hydrogen fluoride by
reacting calcium fluoride with sulfuric acid. Hydrogen fluoride is used
in the production of other compounds, including pharmaceuticals and
polymers. In aqueous solution hydrogen fluoride can be a strong acid.
C. What was the proposed action?
On December 12, 2007 \2\, based on the findings from our RTR, we
proposed no revisions to the four NESHAP regulating the eight source
categories listed in Table 3 and requested public comment.
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\2\ See 72 FR 70543.
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D. What are the conclusions of the residual risk assessment?
As required by section 112(f)(2) of the CAA, we prepared a risk
assessment for each of the eight source categories addressed in this
action to determine the residual risk posed after implementation of the
respective NESHAP. To evaluate the residual risk for each source
category, EPA conducted an inhalation risk assessment \3\ that provided
estimates of MIR, cancer risk distribution within the exposed
populations, cancer incidence, hazard indices (HI) for chronic
exposures to HAP with non-cancer health effects, and hazard quotients
(HQ) for acute exposures to HAP with non-cancer health effects. The
risk assessment consisted of six primary activities: (1) Establishing
the nature and magnitude of emissions from the sources of interest, (2)
identifying the emissions release characteristics (e.g., stack
parameters), (3) conducting dispersion modeling to estimate the
concentrations of HAP in ambient air, (4) estimating long-term and
short-term inhalation exposures to individuals residing within 50 km of
the modeled sources, (5) estimating individual and population-level
risks using the exposure estimates and quantitative dose-response
information, and (6) characterizing risk. In general, the risk
assessment followed a tiered, iterative approach, beginning with a
conservative (worst case) screening-level analysis and, where the
screening analysis indicated the potential for non-negligible risks,
following that with more refined analyses.
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\3\ For more information on the risk assessment inputs and
models, see ``Residual Risk Assessment for Eight Source
Categories,'' available in the docket.
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[[Page 76225]]
The human health risks estimated for the eight source categories
are summarized in Table 4.
Table 4--Summary of Estimated Inhalation Risks for the Eight Source Categories
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Maximum
individual Estimated
cancer risk (in annual cancer Maximum chronic Maximum off-
Number of 1 million) \2\ incidence (and HI \3\ (and HAP site acute HQ
Source category facilities \1\ (and HAP HAP contributing and HAP for
contributing contributing most to which HQ was
most to most to estimate) calculated \4\
estimate) estimate)
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Polysulfide Rubber 1 0 \6\.......... 0 \6\.......... <0.01 (MDI \5\) HQERPG-1=0.0004
Production. (MDI \4\).
Ethylene Propylene Rubber 5 0 \6\.......... 0 \6\.......... 0.5 (hexane)... HQREL=0.3
Production. (toluene).
Butyl Rubber Production..... 2 0 \6\.......... 0 \6\.......... 0.2 (methyl HQERPG-2=0.1
chloride). (methyl
chloride \7\).
Neoprene Production......... 1 0 \6\.......... 0 \6\.......... 0.8 HQREL=0.4
(chloroprene). (toluene).
Epoxy Resins Production..... 3 0.1 0.00002 0.08 HQREL=0.6
(epichlorohydr (epichlorohydr (epichlorohydr (epichlorohydr
in). in). in). in).
Non-nylon Polyamides 4 0.4 0.00003 0.3 HQREL=0.2
Production. (epichlorohydr (epichlorohydr (epichlorohydr (epichlorohydr
in). in). in). in).
Acetal Resins Production.... 3 0.3 (allyl 0.00004 (allyl 0.2 (chlorine). HQREL=2 HQAEGL-
chloride). chloride). 1=0.1
(formaldehyde)
.
Hydrogen Fluoride Production 2 0 \6\.......... 0 \6\.......... <0.01 HQREL=0.3
(hydrofluoric (hydrofluoric
acid). acid).
----------------------------------------------------------------------------------------------------------------
\1\ Number of facilities believed to be in the source category and used in the risk analysis.
\2\ Maximum individual excess lifetime cancer risk.
\3\ Maximum hazard index (HI) is maximum respiratory HI for all except two source categories. Maximum HI for
butyl rubber production is based on neurological effects. Maximum HI for hydrogen fluoride production is based
on skeletal effects.
\4\ The maximum estimated acute exposure concentration was divided by available short-term threshold values to
develop an array of hazard quotient (HQ) values. These include reference exposure level (REL) and ERPG-1 and
ERPG-2 values. The superscript indicates the value to which the acute exposure estimate was compared. The
acute REL is defined by CalEPA as ``the concentration level at or below which no adverse health effects are
anticipated for a specified exposure duration is termed the reference exposure level (REL). REL are based on
the most sensitive, relevant, adverse health effect reported in the medical and toxicological literature. REL
are designed to protect the most sensitive individuals in the population by the inclusion of margins of
safety. Since margins of safety are incorporated to address data gaps and uncertainties, exceeding the REL
does not automatically indicate an adverse health impact.'' The American Industrial Hygiene Association
defines the ERPG-1 as ``the maximum airborne concentration below which it is believed that nearly all
individuals could be exposed for up to 1 hour without experiencing other than mild transient adverse health
effects or without perceiving a clearly defined, objectionable odor'', and the ERPG-2 as ``the maximum
airborne concentration below which it is believed that nearly all individuals could be exposed for up to 1
hour without experiencing or developing irreversible or other serious health effects or symptoms which could
impair an individual's ability to take protective action.'' The National Advisory Committee for Acute Exposure
Guidelines defines AEGL-1 as ``AEGL-1 is the airborne concentration (expressed as ppm or mg/m3) of a substance
above which it is predicted that the general population, including susceptible individuals, could experience
notable discomfort, irritation, or certain asymptomatic nonsensory effects. However, the effects are not
disabling and are transient and reversible upon cessation of exposure.''
\5\ MDI is methylene diphenyl diisocyanate.
\6\ No HAP that are known, probable, or possible human carcinogens are emitted from sources in the category.
\7\ For methyl chloride, REL, and AEGL-1 were not available.
As shown in Table 4, we estimate that the HAP emissions from the
eight source categories affected by this final action do not pose
cancer risks equal to or greater than 1-in-1 million to the individual
most exposed, do not result in meaningful rates of cancer incidence,
and do not result in a concern regarding either chronic or acute
noncancer health effects for the individual most exposed.
In addition, no chronic inhalation human health thresholds were
exceeded at environmental receptors for any of the eight source
categories. As we stated in the preamble to the proposal, we generally
believe that when exposure levels are not anticipated to adversely
affect human health, they also are not anticipated to adversely affect
the environment. Only hydrogen fluoride among those emitted by these
facilities has a potential concern for adverse environmental effects,
based on a consideration of studies in the literature. Accordingly, we
posed the question in the preamble to the proposal whether hydrogen
fluoride emissions impacted vegetation in the vicinity of the two
facilities in the hydrogen fluoride category. No comments were
received. We have concluded that for all facilities in categories
addressed in this rulemaking, there is low potential for adverse
environmental effects due to direct airborne exposures. We also believe
that there is no potential for an adverse effect on threatened or
endangered species or on their critical habitat within the meaning of
50 CFR 402.13(a) because our screening analyses indicate no potential
for any adverse ecological impacts.
Human health multipathway risks were determined not to be a concern
for the eight source categories addressed in this action due to the
absence of persistent and bioaccumulative (PB) \4\ HAP emissions at all
of these sources. The lack of PB HAP emissions also provides assurance
that there will be no potential for adverse ecological effects due to
indirect ecological exposures (i.e., exposures resulting from the
deposition of PB HAP from the atmosphere).
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\4\ Persistent and bioaccumulative (PB) HAP are the list of 14
HAP that have the ability to persist in the environment for long
periods of time and may also have the ability to build up in the
food chain to levels that are harmful to human health and the
environment.
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As a result of these findings, we proposed no additional controls
under the residual risk review requirements of CAA section 112(f)(2).
As EPA has not received evidence which would alter our proposed
decision, we conclude in this rulemaking, as proposed, that no
additional control is required because
[[Page 76226]]
the four NESHAP regulating the eight source categories addressed in
this action provide an ample margin of safety to protect public health
and to prevent an adverse environmental effect.
E. What are the conclusions of the technology review?
Section 112(d)(6) of the CAA requires EPA to review and revise, as
necessary (taking into account developments in practices, processes,
and control technologies), emissions standards promulgated under CAA
section 112 no less often than every 8 years. As we explained in our
CAA section 112(d)(6) determination for the HON (71 FR 34437 and
affirmed at 71 FR 76606),
[a]lthough the language of section 112(d)(6) is nondiscretionary
regarding periodic review, it grants EPA much discretion to revise
the standards ``as necessary.'' Thus, although the specifically
enumerated factors that EPA should consider all relate to technology
(e.g., developments in practices, processes and control
technologies), the instruction to revise ``as necessary'' indicates
that EPA is to exercise its judgment in this regulatory decision,
and is not precluded from considering additional relevant factors,
such as costs and risk. EPA has substantial discretion in weighing
all of the relevant factors in arriving at the best balance of costs
and emissions reduction and determining what further controls, if
any, are necessary. This interpretation is consistent with numerous
rulings by the U.S. Court of Appeals for the DC Circuit regarding
EPA's approach to weighing similar enumerated factors under
statutory provisions directing the Agency to issue technology-based
standards. See, e.g., Husqvarna AB v. EPA, 254 F.3d 195 (DC Cir.
2001). For example, when a section 112(d)(2) MACT standard alone
obtains protection of public health with an ample margin of safety
and prevents adverse environmental effects, it is unlikely that it
would be ``necessary'' to revise the standard further, regardless of
possible developments in control options.\5\ Thus, the section
112(d)(6) review would not need to entail a robust technology
assessment.
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\5\ Although EPA might still consider developments that could
substantially reduce or eliminate risk in a cost-effective manner.
We completed the CAA section 112(d)(6) review for the eight RTR
Group 1 source categories, and, as in our proposal, we concluded that
there have been no significant developments in practices, processes, or
control technologies since promulgation of the MACT standards for the
eight RTR Group 1 source categories. Thus, we proposed no additional
controls were required under the technology review requirements of CAA
section 112(d)(6).
We have not received information that controverts that conclusion.
Therefore, we conclude, as we did in the proposed rule, that no
revisions are required per the provisions of CAA section 112(d)(6).
II. Summary of Comments and Responses
In the proposed action, we requested public comment on our residual
risk reviews and our technology reviews for the eight source categories
listed in Table 3. We received comments from four commenters. The
commenters included one state and local agency association, two
industry trade associations, and representatives of one individual
company. The comments are summarized and our responses to adverse
comments are provided below.\6\ After considering the public comments,
we concluded it was unnecessary to change our risk or technology
reviews or analyses or our determination that the existing MACT
standards for these eight source categories are sufficient under
sections 112(d)(6) and (f)(2) of the CAA.
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\6\ See ``Summary of Public Comments and Responses for RTR Group
1'' for other comment summaries and responses.
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A. Emissions Data
Comment: One commenter expressed concern over the emissions and
emissions release characteristic data the Agency used in its analyses,
noting that the proposal did not explain why state and local air agency
data were not included for source categories where EPA primarily relied
upon industry-supplied data. The commenter recommends that EPA consider
expanding the data set to include state and local information. The
other three commenters believe the data are representative for the RTR
Group 1 source categories, although one of them suggested EPA should
discount the value of emissions inventory data that have not undergone
a quality assurance review.
Response: For the residual risk assessments, we use the best
information available to perform our analyses. The EPA collects
facility-specific emissions and emissions release characteristic
information from state and local agencies periodically, which is then
put into a database called the National Emissions Inventory (NEI). This
information is reviewed by EPA engineers. The information contained in
this database is often the best source of information available to us
and it typically provides the essential parameters for our residual
risk analyses. However, there are limitations to this database, in that
the quality of the data submitted by state and local air agencies
varies. Some parameters in the NEI are not provided by all state and
local air agencies, which means that these parameters are sometimes
blank or are filled in with default values. In addition, if process or
other changes occur at facilities that do not affect their permits,
state or local air agencies may not be aware of these changes, and
subsequently do not submit changes or updates to the emissions for
those facilities.
To analyze risk for these eight source categories, we were able to
use emissions and emissions release characteristic data obtained
directly from industry except for the hydrogen fluoride source category
for which the data were obtained directly from industry and from the
State of Louisiana. Based on our own technical review of these data, we
believe these data are the most accurate data available, and where
available, we used them for our analyses. All of the emissions and
emissions release characteristic data were made available for public
review at the time of the proposal. State and local air agencies, as
well as other members of the public, were invited to provide comments
on the data. We would have considered any substantive comments
regarding the accuracy of the data before promulgating today's decision
not to require new or additional standards; however, other than the
data from Louisiana and one minor comment, addressed below, no such
comments were received from any of the state or local air agencies, or
from any other commenter. Therefore, no significant changes to the data
have been made.
On June 6, 2008, the United States Court of Appeals for the
District of Columbia (the Court) upheld as reasonable EPA's use of
industry data, in that case, where EPA demonstrated that such data
enabled the Agency to assess risk remaining after application of the
National Emission Standards for Organic Hazardous Air Pollutants From
the Synthetic Organic Chemical Manufacturing Industry (HON) \7\, and
noted that ``EPA has wide latitude in determining the extent of data-
gathering necessary to solve a problem.'' \8\
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\7\ Proposed and final National Emission Standards for Organic
Hazardous Air Pollutants from the Synthetic Organic Chemical
Manufacturing Industry (HON) residual risk rules (71 FR 34421, June
14, 2006, and 71 FR 76603, December 21, 2006, respectively).
\8\ See page 17 of the Court Opinion. The Court's opinion was
issued in response to petition received on the final HON RTR. The
Court's opinion, the proposal and final HON RTR rules, and EPA's
Brief for the Respondent are in the RTR Group 1 docket (Docket ID
No. EPA-HQ-OAR-2007-0211).
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Comment: One commenter recommended that EPA include emissions from
startup/shutdown and
[[Page 76227]]
malfunctions (SSM) in its analysis, as they are the cause of
significant HAP emissions and not including them underestimates true
risks.
Response: Emission releases from SSM events are typically
infrequent and of short duration compared to annual emissions. Startup
and shutdown events \9\ usually coincide with routine equipment
maintenance or upset conditions, or with an initial startup of a
process. Malfunction events are sudden and infrequent and must be
corrected as soon as practicable after their occurrence. 40 CFR
63.6(e), which generally applies to all MACT rules in part 63, requires
the owner or operator of a facility to reduce emissions from the
affected source during periods of SSM to the greatest extent which is
consistent with safety and good air pollution control practices.
---------------------------------------------------------------------------
\9\ All three terms are defined in 40 CFR 63.2. ``Malfunction''
means any 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 which
causes, or has the potential to cause, the emission limitations in
an applicable standard to be exceeded. Failures that are caused, in
part, by poor maintenance or careless operation are not
malfunctions. ``Shutdown'' means the cessation of operation of an
affected source or portion of an affected source for any purpose.
``Startup'' means the setting in operation of an affected source or
portion of an affected source for any purpose. And from the 2002
General Provisions for 40 CFR Part 63 BID for Promulgated Amendments
[EPA-453/R-02-002], ``shutdown'' specifically means only the process
of shutting off equipment or a process, and does not refer to the
period of non-operation. Thus, during this period when a process is
offline or between production runs, the source must meet the
standard, including emission limits, as well as monitoring,
recordkeeping, and reporting requirements.
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We believe SSM events do not contribute significantly to cancer or
chronic noncancer risks for the RTR Group 1 source categories because
SSM events are inherently short-term and infrequent relative to annual
operations and emissions. The commenter did not supply data. In
addition, cancer and chronic noncancer risk for the RTR Group 1 source
categories are low. All the RTR Group 1 source categories have a MIR
less than 1-in-1 million and an HI less than 1: emissions from SSM
events would have to be greater than double the annual emission levels
to result in MIR greater than 1-in-1 million or HI greater than 1, and
this is improbable.
To better assess SSM emissions, we analyzed SSM emissions of HAP
from all major industries (primarily petroleum refineries and chemical
manufacturers) in five counties in southeast Texas.\10\ Our analysis of
these data indicates that multiplying the annual average hourly
emission rate by a factor of 10 to estimate the worst-case hourly
emission rate would account for 99 percent of the reported SSM emission
rates. As a result, we apply this default factor of 10 to screen for
potential acute impacts of concern for all RTR source categories. In
this case, use of this factor screened out potential acute impacts from
all RTR Group 1 source categories except for a few facilities from the
Acetal Resins Production and Hydrogen Fluoride Production source
categories.
---------------------------------------------------------------------------
\10\ Our analysis of the SSM data on upset emissions (reported
over an 11 month period in 2001) from the Houston, Texas area showed
that SSM emissions for facilities in this area typically total
significantly less than 15 percent of annual routine emissions,
thereby minimizing their potential to increase chronic health risks
to any significant degree. See Appendix 4 to ``Residual Risk
Assessment for Eight Source Categories: Polysulfide Rubber
Production, Ethylene Propylene Rubber Production, Butyl Rubber
Production, Neoprene Production, Epoxy Resins Production, Non-nylon
Polyamides Production, Hydrogen Fluoride Production, Acetal Resins
Production'' (July 2008), which is available in the RTR Group 1
docket.
---------------------------------------------------------------------------
For acetal resins production and hydrogen fluoride production, we
applied a source category-specific factor of 2 times the average hourly
rate for hydrogen fluoride production and 1.5 times the average hourly
rate for acetal resins production to estimate the worst-case hourly
emission rate. These factors are derived from industry data and one
state that show the peak hourly emissions that have been recorded.
Applying these multipliers to our screening scenario eliminated concern
for the Hydrogen Fluoride Production source category and reduced the
estimated maximum projected acute impact of 1-hour formaldehyde
concentrations at any acetal resins production facility to
approximately twice the reference exposure level (HQREL=2),
and approximately one-tenth the Acute Exposure Guideline Level
(HQAEGL-1=0.1). The REL is a ``concentration level at or
below which no adverse health effects are anticipated for a specified
exposure duration,'' and ``exceeding the REL does not automatically
indicate an adverse health impact.'' Furthermore, we believe that the
likelihood of worst-case meteorological conditions occurring at the
same time as a significant upset event and at the location where human
exposure is the greatest is improbable. Therefore, considering the
value of the maximum HQ along with the improbability of the convergence
of worst-case SSM emissions (which we believe to be infrequent events),
worst-case meteorological conditions and worst-case human exposure, we
determined that this outcome did not warrant cause for concern.
Comment: One commenter noted that they had provided minor updates
to emissions and modeling parameters for three facilities on November
19, 2004, and again in the fall of 2007, but noticed that these updates
were not included in the documentation. The commenter noted that the
updates will have no effect on the cancer MIR modeling and only a minor
impact on the HI, and requested that EPA use the updated information if
it determines additional modeling runs are necessary.
Response: We regret this error and have incorporated these changes
into the datasets for these source categories. As these changes were
very minor, we did not re-model with the updated versions of the data,
as a review of the updated data showed that the risk results would not
be affected to any appreciable degree.
Comment: We received comment both in favor of and objecting to the
use of reported ``actual'' emissions in our analyses. The commenters in
favor of this approach felt actual emissions provide more realistic
estimates of risk. In contrast, one commenter thought actual emissions
and associated impacts could increase over time, and analyses based on
these emissions underestimate residual risk and are inconsistent with
the applicability sections of the MACT standards.
Response: We have discussed the use of both MACT allowable
emissions and actual emissions in previous actions, including the final
National Emission Standards for Coke Oven Batteries residual risk rule
and the proposed and final HON residual risk rules.\11\ In those
previous actions, we noted that modeling the MACT 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 recognize that facilities strive to achieve greater
emissions reductions than required by MACT to allow for process
variability and to prevent exceedances of standards due to emissions
increases on individual days. Thus, failure to consider actual
emissions estimates in
[[Page 76228]]
risk assessments could unrealistically inflate estimated risk levels
because actual emissions estimates represent the typical practices of a
facility.
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\11\ See final National Emission Standards for Coke Oven
Batteries residual risk rule (70 FR 19998-19999, April 15, 2005) and
the proposed and final HON residual risk rules (71 FR 34428, June
14, 2006, and 71 FR 76603, December 21, 2006, respectively.
---------------------------------------------------------------------------
We followed this approach for our analysis for the eight source
categories. As explained in the preamble to the proposed rule, we
evaluated whether allowable emissions would significantly vary from
actual emissions. We concluded that actual emissions approximated
allowable levels for all eight source categories and, thus, were
sufficient for our review. 72 FR 70549-50. We received no comments that
suggested or provided data indicating that actual emissions do not
approximate the allowable levels for these eight source categories.
B. Risk Assessment Methodology
Comment: Comments were received arguing that the Agency's proposed
quantified risks are over-estimated due to the conservative approach
used in predicting risks, which included the use of upper bound unit
risk estimates (URE) for cancer and a 70-year exposure assumption.
Response: We acknowledge that the use of upper bound URE and 70-
year exposure duration are sources of uncertainty in our analyses that
tend to overestimate risk. In general, EPA considers the URE to be an
upper bound estimate based on the method of extrapolation, meaning it
represents a plausible upper limit to the true value. The true risk is,
therefore, likely to be less, though it could be greater, and could be
as low as zero. With regard to exposure duration, we acknowledge that
we did not address long-term population mobility (residence time or
exposure duration) in this assessment or population growth or decline
over 70 years, instead basing our assessment on the assumption that
each person's predicted exposure is constant over the course of a 70-
year lifetime.
As explained in our risk assessment, three metrics are generally
estimated in assessing cancer risk: the MIR, the population risk
distribution, and the cancer incidence. Our failure to consider short-
or long-term population mobility does not bias our estimate of the
theoretical MIR. (Note that the Benzene NESHAP states that the MIR
``does not necessarily reflect the true risk, but displays a
conservative risk level which is an upperbound that is unlikely to be
exceeded.'' \12\) Our estimates of cancer incidence also are not
influenced by our population mobility assumptions, although both the
length of time that modeled emissions sources at facilities actually
operate (i.e., more or less than 70 years), and the domestic growth or
decline of the modeled industry (i.e., the increase or decrease in the
number or size of United States facilities), will influence the cancer
incidence associated with a given source category.
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\12\ 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 (Benzene NESHAP) (54 FR 38045, September
14, 1989).
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Our population mobility (residence time or exposure duration)
assumption does, however, affect the shape of the distribution of
individual risks across the affected population, shifting it toward
higher estimated individual risks at the upper end and reducing the
number of people estimated to be at lower risks, thereby biasing the
risk estimates high.
While the approach we use for our screening analysis is
conservative, we note that where our screening analysis indicates a
potential for risk, we then perform additional, more refined analyses
that more closely approximate the true risk from sources that do not
``screen-out.''
Comment: We received comments both in favor of and objecting to the
use of census block centroids in the analysis of chronic exposure and
risk. One commenter argued that the use of the census block centroid
dilutes the effect of sources' emissions, as the maximum point of
impact can be far from the centroid and may be at or near a facility's
property line, and suggested that the risks for a source category be
based on concentrations at the fenceline and beyond and include risks
to the maximally exposed individual. In contrast, other commenters felt
the use of the census block centroids was appropriate for these source
categories, and one commenter added that using the fenceline as a
location to estimate risk is inappropriate in risk assessment because
people do not generally live at the fenceline, and this approach would
overstate risk.
Response: As we have noted in the development of previous residual
risk rulemakings, such as the HON, EPA contends that, in a national-
scale assessment of lifetime (chronic) 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, such as a
census block centroid. Thus, EPA asserts that it is appropriate to use
census block information where people actually reside rather than
points on a fence-line, to estimate exposure and risk to individuals
living near such facilities when assessing chronic risks. Census blocks
are the finest resolution available in the nationwide population data
(as developed by the United States 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 than is the census block centroid, this may result in an
overestimate or underestimate of the actual annual exposure. Given the
relatively small dimensions of census blocks in densely-populated
areas, there is little uncertainty introduced by using the census block
centroids. There is more uncertainty when census blocks are larger.
Recently, EPA used aerial photographs of several facilities to examine
the locations of census block centroids and actual residences, and to
assess the impact on maximum individual risk of using the census block
centroid.\13\ In cases where census blocks were small, there was no
significant difference in estimated risk. In cases where the census
blocks were relatively large, the centroid generally was found to be
nearer the facility than the residential locations. Consequently, the
risks at the census block centroid typically were higher than the risks
at any actual residence. In most of these cases, the census block
contained a portion of the facility property, thereby almost
necessitating that actual residences be more distant than the block
centroid. This result indicates that, if anything, using census block
centroids is more likely to overestimate actual maximum individual
risks than to underestimate them, although the differences are
generally small. EPA believes it is appropriate to estimate chronic
exposures and risks based on census block centroids because: (1) Census
blocks are the finest resolution available in the national census data,
(2) facility fencelines do not typically
[[Page 76229]]
represent locations where chronic exposures are likely, and (3) any
bias introduced by using census block centroids may overestimate
maximum individual risks.
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\13\ See ``Sensitivity analysis of uncertainty in risk estimates
resulting from estimating exposures at census block centroids near
industrial facilities'' in RTR Group 1 docket.
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III. Risk and Technology Review Final Decision
This final rule responds to public comments received on the
proposed rule and announces our final decision not to revise the
standards of the four NESHAP as they apply to the eight RTR Group 1
source categories. We conclude that the NESHAP applicable to each of
the eight source categories evaluated in RTR Group 1-- Polysulfide
Rubber Production, Ethylene Propylene Rubber Production, Butyl Rubber
Production, Neoprene Production, Epoxy Resins Production, Non-Nylon
Polyamides Production, Acetal Resins Production, and Hydrogen Fluoride
Production--provides an ample margin of safety to protect public health
and prevents adverse environmental effects. Therefore, we are re-
adopting each of the four RTR Group 1 MACT standards for purposes of
meeting the requirements of CAA section 112(f)(2). In addition, we
conclude that there have been no developments in practices, processes,
or control technologies that support revision of the four MACT
standards pursuant to CAA section 112(d)(6) for the eight source
categories.
IV. Statutory and Executive Order Reviews
A. Executive Order 12866, Regulatory Planning and Review
Under Executive Order 12866 (58 FR 51735, October 4, 1993), this
action is a ``significant regulatory action.'' This action is a
significant regulatory action because it raises novel legal and policy
issues. Accordingly, EPA submitted this action to the Office of
Management and Budget (OMB) for review under Executive Order 12866 and
any changes made in response to OMB recommendations have been
documented in the docket for this action.
B. Paperwork Reduction Act
This action does not impose any new information collection burden.
This action makes no changes to the existing regulations affecting the
eight source categories included in this final action and will impose
no additional information collection burden.
C. Regulatory Flexibility Act
The Regulatory Flexibility Act (RFA) generally requires an agency
to prepare a regulatory flexibility analysis of any rule subject to
notice and comment rulemaking requirements under the Administrative
Procedure Act or any other statute unless the agency certifies that the
rule will not have a significant economic impact on a substantial
number of small entities. Small entities include small businesses,
small organizations, and small governmental jurisdictions.
For purposes of assessing the impact of this action on small
entities, small entity is defined as: (1) A small business whose parent
company has fewer than 750 to 1,000 employees, depending on the size
definition for the affected NAICS code (as defined by Small Business
Administration (SBA) regulations at 13 CFR 121.201); (2) a small
governmental jurisdiction that is a government of a city, county, town,
school district, or special district with a population of less than
50,000; and (3) a small organization that is any not-for-profit
enterprise which is independently owned and operated and is not
dominant in its field.
After considering the economic impacts of this action on small
entities, I certify that this action will not have a significant
economic impact on a substantial number of small entities. This final
decision does not impose any requirements on small entities.
D. Unfunded Mandates Reform Act
This action contains no Federal mandates under the provisions of
Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), 2 U.S.C.
1531-1538 for state, local, and tribal governments or the private
sector. The action imposes no enforceable duty on any state, local, or
tribal governments or the private sector. Therefore, this action is not
subject to the requirements of sections 202 or 205 of the UMRA.
This action is also not subject to the requirements of section 203
of UMRA because it contains no regulatory requirements that might
significantly or uniquely affect small governments. This action makes
no changes to the existing regulations affecting the eight source
categories included in this final action; and, therefore, contains no
requirements that apply to such governments or impose obligations upon
them.
E. Executive Order 13132, Federalism
Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August
10, 1999), requires EPA to develop an accountable process to ensure
``meaningful and timely input by state and local officials in the
development of regulatory policies that have federalism implications.''
``Policies that have federalism implications'' is defined in the
Executive Order to include regulations that have ``substantial direct
effects on the states, on the relationship between the national
government and the states, or on the distribution of power and
responsibilities among the various levels of government.''
This final decision does not have federalism implications. It will
not have substantial direct effects on the states, on the relationship
between the national government and the states, or on the distribution
of power and responsibilities among the various levels of government,
as specified in Executive Order 13132. Thus, Executive Order 13132 does
not apply to this action.
F. Executive Order 13175, Consultation and Coordination With Indian
Tribal Governments
This action does not have tribal implications, as specified in
Executive Order 13175 (65 FR 67249, November 9, 2000). It will not have
substantial direct effect on tribal governments, on the relationship
between the Federal government and Indian tribes, or on the
distribution of power and responsibilities between the Federal
government and Indian tribes, as specified in Executive Order 13175.
Thus, Executive Order 13175 does not apply to this action.
G. Executive Order 13045: Protection of Children From Environmental
Health Risks and Safety Risks
This action is not subject to Executive Order 13045 (62 FR 19885,
April 23, 1997) because it is not economically significant as defined
in Executive Order 12866, and because the Agency does not believe the
environmental health or safety risks addressed by this action present a
disproportionate risk to children. Discussion of this action's health
and risk assessments are contained in Section I of this preamble.
H. Executive Order 13211, Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
This final decision is not a ``significant energy action'' as
defined in Executive Order 13211 (66 FR 28355, May 22, 2001) because it
is not likely to have a significant adverse effect on the supply,
distribution, or use of energy. Further, we have concluded that this
final decision is not likely to have any adverse energy effects.
I. National Technology Transfer and Advancement Act
Section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (NTTAA), Public Law No.
[[Page 76230]]
104-113, 12(d) (15 U.S.C. 272 note) directs EPA to use voluntary
consensus standards (VCS) in its regulatory activities unless to do so
would be inconsistent with applicable law or otherwise impractical. VCS
are technical standards (e.g., materials specifications, test methods,
sampling procedures, and business practices) that are developed or
adopted by VCS bodies. NTTAA directs EPA to provide Congress, through
OMB, explanations when the Agency decides not to use available and
applicable VCS.
This action does not involve technical standards. Therefore, EPA
did not consider the use of any VCS.
J. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations
Executive Order 12898 (59 FR 7629, February 16, 1994) establishes
Federal executive policy on environmental justice. Its main provision
directs Federal agencies, to the greatest extent practicable and
permitted by law, to make environmental justice part of their mission
by identifying and addressing, as appropriate, disproportionately high
and adverse human health or environmental effects of their programs,
policies, and activities on minority populations and low-income
populations in the United States.
EPA has determined that this final rule will not have
disproportionately high and adverse human health or environmental
effects on minority or low-income populations because it does not
affect the level of protection provided to human health or the
environment. This rule would not relax the control measures on sources
regulated by the rule and, therefore, would not cause emissions
increases from these sources.
K. Congressional Review Act
The Congressional Review Act, 5 U.S.C. 801, et seq., as added by
the Small Business Regulatory Enforcement Fairness Act of 1996,
generally provides that before a rule may take effect, the agency
promulgating the rule must submit a rule report, which includes a copy
of the rule, to each House of the Congress and to the Comptroller
General of the United States. EPA will submit a report containing these
final rules and other required information to the United States Senate,
the United States House of Representatives, and the Comptroller General
of the United States prior to publication of the final rules in the
Federal Register. A major rule cannot take effect until 60 days after
it is published in the Federal Register . This action is not a ``major
rule'' as defined by 5 U.S.C. 804(2). This final rule will be effective
on December 16, 2008.
List of Subjects for 40 CFR Part 63
Environmental protection, Administrative practice and procedures,
Air pollution control, Hazardous substances, Intergovernmental
relations, Reporting and recordkeeping requirements.
Dated: December 10, 2008.
Stephen L. Johnson,
Administrator.
[FR Doc. E8-29789 Filed 12-15-08; 8:45 am]
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