[Federal Register Volume 76, Number 227 (Friday, November 25, 2011)]
[Proposed Rules]
[Pages 72770-72819]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-29454]



[[Page 72769]]

Vol. 76

Friday,

No. 227

November 25, 2011

Part II





Environmental Protection Agency





-----------------------------------------------------------------------





40 CFR Part 63





 National Emissions Standards for Hazardous Air Pollutants: Mineral 
Wool Production and Wool Fiberglass Manufacturing; Proposed Rule

  Federal Register / Vol. 76 , No. 227 / Friday, November 25, 2011 / 
Proposed Rules  

[[Page 72770]]


-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2010-1041, EPA-HQ-OAR-2010-1042; FRL-9491-9]
RIN 2060-AQ90


National Emissions Standards for Hazardous Air Pollutants: 
Mineral Wool Production and Wool Fiberglass Manufacturing

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

-----------------------------------------------------------------------

SUMMARY: The EPA is proposing amendments to the national emissions 
standards for hazardous air pollutants for Mineral Wool Production and 
Wool Fiberglass Manufacturing to address the results of the residual 
risk and technology review that the EPA is required to conduct by the 
Clean Air Act. The proposed Mineral Wool Production amendments include 
emissions limits for carbonyl sulfide, hydrogen fluoride and 
hydrochloric acid for cupolas; add combined collection and curing 
processes as new regulated sources; and include emissions limits for 
formaldehyde, phenol and methanol for combined collection and curing 
operations. Modifications to the testing and monitoring and related 
notification, recordkeeping and reporting requirements are also 
proposed.
    The proposed amendments for the Wool Fiberglass Manufacturing 
source category include emissions limits for chromium compounds, 
hydrogen fluoride, hydrochloric acid and particulate matter for glass-
melting furnaces at major sources; revised emissions limits for 
formaldehyde, and the addition of emissions limits for phenol and 
methanol for bonded product lines at major sources; and modifications 
to testing and monitoring and related notification, recordkeeping and 
reporting requirements.
    These proposed rules only apply to major sources, but we plan to 
regulate wool fiberglass area sources in a future action.
    We are also proposing to revise provisions addressing periods of 
startup, shutdown and malfunction to ensure that the rules are 
consistent with a recent court decision.

DATES: Comments must be received on or before January 24, 2012. Under 
the Paperwork Reduction Act, comments on the information collection 
provisions are best assured of having full effect if the Office of 
Management and Budget receives a copy of your comments on or before 
December 27, 2011.
    Public Hearing. If anyone contacts the EPA requesting to speak at a 
public hearing by December 5, 2011, a public hearing will be held on 
December 12, 2011.

ADDRESSES: Submit your comments, identified by Docket ID Numbers EPA-
HQ-OAR-2010-1041 and EPA-HQ-OAR-2010-1042, by one of the following 
methods:
     http://www.regulations.gov: Follow the on-line 
instructions for submitting comments.
     Email: [email protected], Attention Docket ID Number 
EPA-HQ-OAR-2010-1041 and EPA-HQ-OAR-2010-1042.
     Fax: (202) 566-9744, Attention Docket ID Number EPA-HQ-
OAR-2010-1041 or EPA-HQ-OAR-2010-1042.
     Mail: U.S. Postal Service, send comments to: EPA Docket 
Center, EPA West (Air Docket), Attention Docket ID Number EPA-HQ-OAR-
2010-1041 or EPA-HQ-OAR-2010-1042, U.S. Environmental Protection 
Agency, Mailcode: 2822T, 1200 Pennsylvania Ave. NW., Washington, DC 
20460. Please include a total of two copies. In addition, please mail a 
copy of your comments on the information collection provisions to the 
Office of Information and Regulatory Affairs, Office of Management and 
Budget, Attn: Desk Officer for EPA, 725 17th Street NW., Washington, DC 
20503.
     Hand Delivery: U.S. Environmental Protection Agency, EPA 
West (Air Docket), Room 3334, 1301 Constitution Ave. NW., Washington, 
DC 20004, Attention Docket ID Number EPA-HQ-OAR-2010-1041 or EPA-HQ-
OAR-2010-1042. Such deliveries are only accepted during the Docket's 
normal hours of operation, and special arrangements should be made for 
deliveries of boxed information.
    Instructions. Direct your comments on the Mineral Wool RTR to 
Docket ID Number EPA-HQ-OAR-2010-1041 and direct your comments on the 
Wool Fiberglass RTR to Docket ID Number EPA-HQ-OAR-2010-1042. The EPA's 
policy is that all comments received will be included in the public 
docket without change and may be made available on-line at http://www.regulations.gov, including any personal information provided, 
unless the comment includes information claimed to be CBI or other 
information whose disclosure is restricted by statute. Do not submit 
information that you consider to be CBI or otherwise protected through 
http://www.regulations.gov or email. The http://www.regulations.gov Web 
site is an ``anonymous access'' system, which means the EPA will not 
know your identity or contact information unless you provide it in the 
body of your comment. If you send an email comment directly to the EPA 
without going through http://www.regulations.gov, your email address 
will be automatically captured and included as part of the comment that 
is placed in the public docket and made available on the Internet. If 
you submit an electronic comment, the EPA recommends that you include 
your name and other contact information in the body of your comment and 
with any disk or CD-ROM you submit. If the EPA cannot read your comment 
due to technical difficulties and cannot contact you for clarification, 
the EPA may not be able to consider your comment. Electronic files 
should avoid the use of special characters, any form of encryption, and 
be free of any defects or viruses. For additional information about the 
EPA's public docket, visit the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm.
    Docket. The EPA has established dockets for this rulemaking under 
Docket ID Number EPA-HQ-OAR-2010-1041 (Mineral Wool Production) and 
EPA-HQ-OAR-2010-1042 (Wool Fiberglass Manufacturing). All documents in 
the docket are listed in the http://www.regulations.gov index. Although 
listed in the index, some information is not publicly available, e.g., 
CBI 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. Publicly 
available docket materials are available either electronically in 
http://www.regulations.gov or in hard copy at the EPA Docket Center, 
EPA West, Room 3334, 1301 Constitution Ave. 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 proposed 
action, contact Ms. Susan Fairchild, Sector Policies and Programs 
Division (D243-04), Office of Air Quality Planning and Standards, U.S. 
Environmental Protection Agency, Research Triangle Park, North Carolina 
27711, telephone (919) 541-5167; fax number: (919) 541-

[[Page 72771]]

3207; and email address: [email protected]. For specific 
information regarding the risk modeling methodology, contact Mr. Chris 
Sarsony, Health and Environmental Impacts Division (C539-02), Office of 
Air Quality Planning and Standards, U.S. Environmental Protection 
Agency, Research Triangle Park, North Carolina 27711; telephone number: 
(919) 541-4843; fax number: (919) 541-0840; and email address: 
[email protected]. For information about the applicability of the 
NESHAP to a particular entity, contact Scott Throwe, Office of 
Enforcement and Compliance Assurance; U.S. EPA Headquarters Ariel Rios 
Building; 1200 Pennsylvania Avenue NW. Mail Code: 2227A; Washington, DC 
20460; telephone number: (202) 564-7013; fax number: (202) 564-0050; 
email address: [email protected].

SUPPLEMENTARY INFORMATION:
    Organization of this Document. The information in this preamble is 
organized as follows:

I. Preamble Acronyms and Abbreviations
II. General Information
    A. Does this action apply to me?
    B. Where can I get a copy of this document and other related 
information?
    C. What should I consider as I prepare my comments for the EPA?
    D. When will a public hearing occur?
III. Background Information
    A. What are NESHAP?
    B. What litigation is related to this proposed action?
IV. Mineral Wool and Wool Fiberglass Source Categories
    A. Overview of the Mineral Wool Production Source Category and 
MACT Standards
    B. Overview of the Wool Fiberglass Manufacturing Source Category 
and 1999 MACT Rule
    C. What data collection activities were conducted to support 
this action?
V. Analyses Performed
    A. How did we estimate risks posed by the source categories?
    B. How did we consider the risk results in making decisions for 
this proposal?
    C. How did we perform the technology review?
    D. What other issues are we addressing in this proposal?
    E. What analyses were performed for the Mineral Wool Production 
source category under the Regulatory Flexibility Act?
VI. Summary of Proposed Decisions and Actions
    A. What are the proposed decisions and actions related to the 
Mineral Wool Production NESHAP?
    B. What are the proposed decisions and actions related to the 
Wool Fiberglass Manufacturing NESHAP?
    C. What are the proposed decisions and actions related to 
startup, shutdown and malfunction?
    D. What are the proposed decisions and actions related to 
electronic reporting?
VII. Rationale for the Proposed Actions for the Mineral Wool 
Production Source Category
    A. What data were used for the NESHAP analyses?
    B. What are the proposed decisions regarding surrogacy 
relationships?
    C. What are the proposed decisions regarding certain unregulated 
emissions sources?
    D. What are the proposed decisions regarding subcategorization?
    E. What are the results from the risk assessments performed and 
the proposed decisions for the Mineral Wool Production source 
category?
    F. What are our proposed decisions for the Mineral Wool 
Production source category based on risk acceptability and ample 
margin of safety?
    G. What are the results from the technology review and proposed 
decisions?
VIII. Rationale for the Proposed Actions for the Wool Fiberglass 
Manufacturing Source Category
    A. What data were used for the NESHAP analyses?
    B. What are the proposed decisions regarding surrogacy 
relationships?
    C. What are the proposed decisions regarding certain unregulated 
emissions sources?
    D. What are the results from the risk assessments and analyses 
and the proposed decisions for the Wool Fiberglass Manufacturing 
Source Category?
    E. What are our proposed decisions for the Wool Fiberglass 
Manufacturing source category based on risk acceptability and ample 
margin of safety?
    F. What are the results from the technology review and proposed 
decisions?
IX. Summary of Cost, Environmental, and Economic Impacts for the 
Mineral Wool Source Category
    A. What are the affected sources in the Mineral Wool Production 
source category?
    B. How are the impacts for this proposal evaluated?
    C. What are the air quality impacts for the Mineral Wool 
Production source category?
    D. What are the water quality and solid waste impacts?
    E. What are the secondary impacts?
    F. What are the energy impacts?
    G. What are the cost impacts for the Mineral Wool Production 
source category?
    H. What are the economic impacts for the Mineral Wool Production 
source category?
    I. What are the benefits for the Mineral Wool Production source 
category?
    J. What demographic groups might benefit the most from this 
regulation?
X. Summary of Cost, Environmental, and Economic Impacts for the Wool 
Fiberglass Manufacturing Source Category
    A. What are the affected sources in the Wool Fiberglass 
Manufacturing source category?
    B. How are the impacts for this proposal evaluated?
    C. What are the air quality impacts?
    D. What are the water quality and solid waste impacts?
    E. What are the secondary impacts?
    F. What are the energy impacts?
    G. What are the cost impacts?
    H. What are the economic impacts?
    I. What are the benefits?
    J. What demographic groups might benefit the most from this 
regulation?
XI. Request for Comments
XII. Submitting Data Corrections
XIII. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulation and Regulatory 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
    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. Preamble Acronyms and Abbreviations

    Several acronyms and terms used to describe industrial processes, 
data inventories, and risk modeling are included in this preamble. 
While this may not be an exhaustive list, to ease the reading of this 
preamble and for reference purposes, the following terms and acronyms 
are defined here:

ACGIH American Conference of Governmental Industrial Hygienists
AEGL acute exposure guideline levels
AERMOD air dispersion model used by the HEM-3 model
ATSDR Agency for Toxic Substances and Disease Registry
BACT best available control technology
BLDS bag leak detection systems
BTF beyond the floor
CAA Clean Air Act
CalEPA California EPA
CA-REL California reference exposure level
CBI Confidential Business Information
CFR Code of Federal Regulations
CIIT Chemical Industry Institute of Toxicology
CO carbon monoxide
COS Carbonyl sulfide
EJ environmental justice
EPA Environmental Protection Agency
ERPG Emergency Response Planning Guidelines
ERT Electronic Reporting Tool
ESP electrostatic precipitators

[[Page 72772]]

FA flame attenuation
GP General Provisions
GHG Greenhouse Gases
HAP hazardous air pollutants
HCl Hydrogen chloride
HEM Human Exposure Model
HEM-3 Human Exposure Model, Version 3
HF Hydrogen fluoride
HI Hazard Index
HQ Hazard Quotient
IRFA Initial Regulatory Flexibility Analysis
IRIS Integrated Risk Information System
kg/MG kilogram/megawatt
km kilometer
LAER lowest achievable emissions rate
lb/ton pounds per ton
lb/yr pounds per year
MACT maximum achievable control technology
mg/L milligrams per liter
mg/m3 milligrams per cubic meter
MIR maximum individual risk
NAAQS National Ambient Air Quality Standard
NAICS North American Industry Classification System
NaOH sodium hydroxide
NAS National Academy of Sciences
NATA National Air Toxics Assessment
NESHAP National Emissions Standards for Hazardous Air Pollutants
NIOSH National Institutes for Occupational Safety and Health
NRC National Research Council
NTTAA National Technology Transfer and Advancement Act
OAQPS Office of Air Quality Planning and Standards
OMB Office of Management and Budget
PB-HAP hazardous air pollutants known to be persistent and bio-
accumulative in the environment
PM particulate matter
RACT reasonably available control technology
RBLC RACT/BACT/LAER Clearinghouse
RCRA Resource Conservation and Recovery Conservation
REL reference exposure level
RFA Regulatory Flexibility Act
RfC reference concentrations
RfD reference dose
RS rotary spin
RTO regenerative thermal oxidizers
RTR residual risk and technology review
SAB Science Advisory Board
SBA Small Business Administration
SBAR Small Business Advocacy Review
SCC Source Classification Codes
SER Small Entity Representatives
SO2 sulfur dioxide
SSM startup, shutdown, and malfunction
TC Toxicity Characteristics
TCLP Toxicity Characteristic Leaching Procedure
TLV threshold limit value
TOSHI target organ-specific hazard index
tpy tons per year
TRIM Total Risk Integrated Modeling System
TTN Technology Transfer Network
UF uncertainty factors
[micro]g/m3 microgram per cubic meter
UMRA Unfunded Mandates Reform Act
UPL upper predictive limit
URE unit risk estimate
WHO World Health Organization
WWW worldwide web

II. General Information

A. Does this action apply to me?

    The regulated industrial source categories that are the subject of 
this proposed rule are listed in Table 1 of this preamble. Table 1 of 
this preamble is not intended to be exhaustive, but rather provides a 
guide for readers regarding the entities likely to be affected by this 
proposed action. These standards, once finalized, will be directly 
applicable to affected sources. Federal, state, local, and Tribal 
government entities are not affected by this proposed action.
    In 1992 the EPA defined the Mineral Wool Production source category 
as any facility engaged in producing mineral wool fiber from slag or 
rock. Mineral wool is a material used mainly for thermal and acoustical 
insulation. This category includes, but is not limited to, the 
following process units: a cupola furnace for melting the mineral 
charge; a blow chamber in which air and, in some cases, a binder is 
drawn over the fibers, forming them to a screen; a curing oven to bond 
the fibers; and a cooling compartment.
    In 1992 the EPA defined the Wool Fiberglass Manufacturing source 
category as any facility engaged in producing wool fiberglass from 
sand, feldspar, sodium sulfate, anhydrous borax, boric acid or any 
other materials. In the wool fiberglass manufacturing process, molten 
glass is formed into fibers that are bonded with an organic resin to 
create a wool-like material that is used as thermal or acoustical 
insulation. The category includes, but is not limited to the following 
processes: glass-melting furnace, marble forming, refining, fiber 
forming, binder application, curing and cooling.

    Table 1--NESHAP and Industrial Source Categories Affected by This
                             Proposed Action
------------------------------------------------------------------------
       Source category                   NESHAP           NAICS code \1\
------------------------------------------------------------------------
Mineral Wool Production......  Mineral Wool Production..          327993
Wool Fiberglass Manufacturing  Wool Fiberglass                    327993
                                Manufacturing.
------------------------------------------------------------------------
\1\ North American Industry Classification System.

B. Where can I get a copy of this document and other related 
information?

    In addition to being available in the docket, an electronic copy of 
this proposal will also be available on the WWW through the EPA's TTN. 
Following signature by the EPA Administrator, a copy of this proposed 
action will be posted on the TTN's policy and guidance page for newly 
proposed or promulgated rules at the following address: http://www.epa.gov/ttn/atw/rrisk/rtrpg.html. In addition, a copy of each rule 
showing specific changes proposed under this action is available in 
their respective dockets. The TTN provides information and technology 
exchange in various areas of air pollution control.

C. What should I consider as I prepare my comments for the EPA?

    Submitting CBI. Do not submit information containing CBI to the EPA 
through http://www.regulations.gov or email. Clearly mark the part or 
all of the information that you claim to be CBI. For CBI information on 
a disk or CD-ROM that you mail to the EPA, mark the outside of the disk 
or CD-ROM as CBI and then identify electronically within the disk or 
CD-ROM the specific information that is claimed as CBI. In addition to 
one complete version of the comment that includes information claimed 
as CBI, a copy of the comment that does not contain the information 
claimed as CBI must be submitted for inclusion in the public docket. If 
you submit a CD-ROM or disk that does not contain CBI, mark the outside 
of the disk or CD-ROM clearly indicating that it does not contain CBI. 
Information not marked as CBI will be included in the public docket and 
the EPA's electronic public docket without prior notice. Information 
marked as CBI will not be disclosed except in accordance with 
procedures set forth in 40 CFR part 2. Send or deliver information 
identified as CBI only to the following address: Roberto Morales, OAQPS 
Document Control Officer (C404-02), Office of Air Quality Planning and 
Standards, U.S. Environmental Protection Agency,

[[Page 72773]]

Research Triangle Park, North Carolina 27711, Attention Docket ID 
Number EPA-HQ-OAR-2010-1041 (Mineral Wool RTR) or Attention Docket ID 
Number EPA-HQ-OAR-2010-1042 (Wool Fiberglass RTR).

D. When will a public hearing occur?

    If a public hearing is held, it will begin at 10 a.m. on December 
12, 2011 and will be held at a location to be determined. Persons 
interested in presenting oral testimony or inquiring as to whether a 
public hearing is to be held should contact Ms. Pamela Garrett, Office 
of Air Quality Planning and Standards, Sector Policies and Programs 
Division, (D243-01), U.S. Environmental Protection Agency, Research 
Triangle Park, North Carolina 27711; telephone number: (919) 541-7996; 
email address: [email protected].

III. Background Information

A. What are NESHAP?

1. What is the statutory authority for NESHAP?
    Section 112 of the CAA establishes a two-stage regulatory process 
to address emissions of HAP from stationary sources. In the first 
stage, after the EPA has identified categories of sources emitting one 
or more of the HAP listed in CAA section 112(b), CAA section 112(d) 
calls for us to promulgate NESHAP for those sources. ``Major sources'' 
are those that emit or have the potential to emit 10 tpy or more of a 
single HAP or 25 tpy or more of any combination of HAP. For major 
sources, these technology-based standards must reflect the maximum 
degree of emissions reductions of HAP achievable (after considering 
cost, energy requirements, and non-air quality health and environmental 
impacts) and are commonly referred to as MACT standards. Area sources 
are those that emit less than major amounts of HAP.
    MACT standards must require the maximum degree of emissions 
reduction through the application of measures, processes, methods, 
systems, or techniques, including, but not limited to, measures that 
(A) reduce the volume of or eliminate pollutants through process 
changes, substitution of materials or other modifications; (B) enclose 
systems or processes to eliminate emissions; (C) capture or treat 
pollutants when released from a process, stack, storage or fugitive 
emissions point; (D) are design, equipment, work practice or 
operational standards (including requirements for operator training or 
certification); or (E) are a combination of the above (CAA section 
112(d)(2)(A)-(E)). The MACT standards may take the form of design, 
equipment, work practice or operational standards where the EPA first 
determines either that, (A) a pollutant cannot be emitted through a 
conveyance designed and constructed to emit or capture the pollutants, 
or that any requirement for, or use of, such a conveyance would be 
inconsistent with law; or (B) the application of measurement 
methodology to a particular class of sources is not practicable due to 
technological and economic limitations (CAA sections 112(h)(1)-(2)).
    The MACT ``floor'' is the minimum control level allowed for MACT 
standards promulgated under CAA section 112(d)(3) and may not be based 
on cost considerations. For new sources, the MACT floor cannot be less 
stringent than the emissions control that is achieved in practice by 
the best-controlled similar source. The MACT floors for existing 
sources can be less stringent than floors for new sources, but they 
cannot be less stringent than the average emissions limitation achieved 
by the best-performing 12 percent of existing sources in the category 
or subcategory (or the best-performing 5 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 considerations of the cost of achieving the 
emissions reductions, any non-air quality health and environmental 
impacts, and energy requirements.
    The EPA is then required to review these technology-based standards 
and 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 conducting this 
review, the EPA is not obliged to completely recalculate the prior MACT 
determination, and, in particular, is not obligated to recalculate the 
MACT floors. NRDC v. EPA, 529 F.3d 1077, 1084 (DC Cir., 2008).
    The second stage in standard-setting focuses on reducing any 
remaining ``residual'' risk according to CAA section 112(f). This 
provision requires, first, that the EPA prepare a Report to Congress 
discussing (among other things) methods of calculating the risks posed 
(or potentially posed) by sources after implementation of the MACT 
standards, the public health significance of those risks, and the EPA's 
recommendations as to legislation regarding such remaining risk. The 
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 the EPA's obligation under 
CAA section 112(f)(2) to analyze and address residual risk.
    Section 112(f)(2) of the CAA requires us to determine, for source 
categories subject to certain MACT standards, whether those emissions 
standards provide an ample margin of safety to protect public health. 
If the MACT standards that apply to a source category emitting a HAP 
that is ``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 one-in-one million,'' the 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 (CAA section 
112(f)(2)(A)). This requirement is procedural. It mandates that the EPA 
establish CAA section 112(f) residual risk standards if certain risk 
thresholds are not satisfied, but does not determine the level of those 
standards (NRDC v. EPA, 529 F. 3d at 1083). The second sentence of CAA 
section 112(f)(2) sets out the substantive requirements for residual 
risk standards: Protection of public health with an ample margin of 
safety based on the EPA's interpretation of this standard in effect at 
the time of the CAA amendments. Id. This refers to the National 
Emissions Standards for Hazardous Air Pollutants: Benzene Emissions 
from Maleic Anhydride Plants, Ethylbenzene/Styrene Plants, Benzene 
Storage Vessels, Benzene Equipment Leaks, and Coke By-Product Recovery 
Plants (Benzene NESHAP), (54 FR 38044, September 14, 1989), described 
in the next paragraph.
    The EPA may adopt residual risk standards equal to existing MACT 
standards if the EPA determines that the existing standards are 
sufficiently protective, even if (for example) excess cancer risks to a 
most exposed individual are not reduced to less than one-in-one 
million. Id. at 1083 (``If the 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''). Section 112(f)(2) of the CAA further authorizes the EPA 
to adopt more stringent standards, if necessary ``to prevent, taking 
into consideration costs, energy, safety, and other relevant

[[Page 72774]]

factors, an adverse environmental effect.'' \1\
---------------------------------------------------------------------------

    \1\ ``Adverse environmental effect'' is defined in CAA section 
112(a)(7) as any significant and widespread adverse effect, which 
may be reasonably anticipated to wildlife, aquatic life, or natural 
resources, including adverse impacts on populations of endangered or 
threatened species or significant degradation of environmental 
qualities over broad areas.
---------------------------------------------------------------------------

    CAA section 112(f)(2) expressly preserves our use of the two-step 
process for developing standards to address any residual risk and our 
interpretation of ``ample margin of safety'' developed in the Benzene 
NESHAP. The first step in this process is the determination of 
acceptable risk. This determination ``considers all health information, 
including risk estimation uncertainty, and includes a presumptive limit 
on MRI [cancer] \2\ of approximately 1-in-10 thousand [i.e., 100-in-1 
million]'' (54 FR 38045). In the second step of the process, the EPA 
sets the standard at a level that provides an ample margin of safety 
``in consideration of all health information, including the number of 
persons at risk levels higher than approximately 1-in-1 million, as 
well as other relevant factors, including costs and economic impacts, 
technological feasibility, and other factors relevant to each 
particular decision'' (Id.)
---------------------------------------------------------------------------

    \2\ Although defined as ``maximum individual risk,'' MIR refers 
only to cancer risk. MIR, one metric for assessing cancer risk, is 
the estimated risk were an individual exposed to the maximum level 
of a pollutant for a lifetime.
---------------------------------------------------------------------------

    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) preserves the EPA's interpretation 
set out in the Benzene NESHAP, and the Court in NRDC v. EPA concluded 
that the EPA's interpretation of CAA section 112(f)(2) is a reasonable 
one. See NRDC v. EPA, 529 F.3d at 1083 (DC Cir. 2008), which says 
``[S]ubsection 112(f)(2)(B) expressly incorporates the EPA's 
interpretation of the CAA from the Benzene standard, complete with a 
citation to the Federal Register.'' See also, A Legislative History of 
the Clean Air Act Amendments of 1990, volume 1, p. 877 (Senate debate 
on Conference Report). We also 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 risks 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, the EPA 
does not define ``rigid line[s] of acceptability,'' but rather 
considers broad objectives to be weighed with a 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 DC Circuit's en banc Vinyl 
Chloride decision at 824 F.2d 1165) recognizing that our world is not 
risk-free.
    In the Benzene NESHAP, we stated that ``the 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 38045. We discussed the maximum 
individual lifetime cancer risk 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 upper bound of risk based 
on conservative assumptions, such as continuous exposure for 24 hours 
per day for 70 years.'' Id. We acknowledge that maximum individual 
lifetime cancer risk ``does not necessarily reflect the true risk, but 
displays a conservative risk level which is an upper-bound that is 
unlikely to be exceeded.'' Id.
    Understanding that there are both benefits and limitations to using 
maximum individual lifetime cancer risk 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 maximum 
individual lifetime cancer risk, 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 [maximum individual cancer 
risk], rather than a 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- 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-emissions 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 maximum individual lifetime 
cancer risk alone. As explained in the Benzene NESHAP, ``[e]ven though 
the risks judged `acceptable' by the 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 ample margin of safety decision process, the agency 
again considers all of the health risks 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 and prevent adverse environmental effects, 
taking into consideration costs, energy, safety, and other relevant 
factors, as

[[Page 72775]]

required by CAA section 112(f) (54 FR 38046).
2. How do we consider the risk results in making decisions?
    In past residual risk determinations, the EPA presented a number of 
human health risk metrics associated with emissions from the category 
under review, including: the MIR; the numbers of persons in various 
risk ranges; cancer incidence; the maximum noncancer HI; and the 
maximum acute noncancer hazard. In estimating risks, the EPA considered 
source categories under review that are located near each other and 
that affect the same population. The EPA provided estimates of the 
expected difference in actual emissions from the source category under 
review and emissions allowed pursuant to the source category MACT 
standard. The EPA also discussed and considered risk estimation 
uncertainties. The EPA is providing this same type of information in 
support of these actions.
    The agency acknowledges that the Benzene NESHAP provides 
flexibility regarding what factors the EPA might consider in making our 
determinations and how they might be weighed for each source category. 
In responding to comment on our policy under the Benzene NESHAP, the 
EPA explained that: ``The policy chosen by the Administrator permits 
consideration of multiple measures of health risk. Not only can the MIR 
figure be considered, but also incidence, the presence of noncancer 
health effects, and the uncertainties of the risk estimates. In this 
way, the effect on the most exposed individuals can be reviewed as well 
as the impact on the general public. These factors can then be weighed 
in each individual case. This approach complies with the Vinyl Chloride 
mandate that the Administrator ascertain an acceptable level of risk to 
the public by employing [her] expertise to assess available data. It 
also complies with the Congressional intent behind the CAA, which did 
not exclude the use of any particular measure of public health risk 
from the EPA's consideration with respect to CAA section 112 
regulations, and, thereby, implicitly permits consideration of all 
measures of health risk which the Administrator, in [her] judgment, 
believes are appropriate to determining what will `protect the public 
health.' ''
    For example, the level of the MIR is only one factor to be weighed 
in determining acceptability of risks. The Benzene NESHAP explains ``an 
MIR of approximately 1-in-10 thousand should ordinarily be the upper 
end of the range of acceptability. As risks increase above this 
benchmark, they become presumptively less acceptable under CAA section 
112, and would be weighed with the other health risk measures and 
information in making an overall judgment on acceptability. Or, the 
agency may find, in a particular case, that a risk that includes an MIR 
less than the presumptively acceptable level is unacceptable in the 
light of other health risk factors.'' Similarly, with regard to the 
ample margin of safety analysis, the Benzene NESHAP states that: ``the 
EPA believes the relative weight of the many factors that can be 
considered in selecting an ample margin of safety can only be 
determined for each specific source category. This occurs mainly 
because technological and economic factors (along with the health-
related factors) vary from source category to source category.''

B. What litigation is related to this proposed action?

    In 2007, the DC Circuit (Court) found that the EPA had erred in 
establishing emissions standards for sources of HAP in the NESHAP for 
Brick and Structural Clay Products Manufacturing and Clay Ceramics 
Manufacturing, 67 FR 26,690 (May 16, 2003), and consequently vacated 
the rule.\3\ These errors included incorrectly calculated MACT emission 
limits, instances where EPA failed to set emission limits, and 
instances where EPA failed to regulate processes that emitted HAP. We 
are taking action to correct errors in both the Mineral Wool and Wool 
Fiberglass NESHAP for HAP that are not regulated. Some pollutants were 
represented in the 1999 MACT rules by surrogates; other pollutants were 
not regulated at all in the rule. In both these cases, we are 
establishing pollutant-specific emission limits. With the exception of 
PM as a surrogate for all HAP metals, where surrogacy relationships 
exist, we are proposing to remove that surrogacy. We are also 
correcting one unregulated HAP-emitting process in the Mineral Wool 
NESHAP.
---------------------------------------------------------------------------

    \3\ Sierra Club v. EPA, 479 F. 3d 875 (DC Cir. March 13, 2007).
---------------------------------------------------------------------------

    In two earlier court decisions 4 5 the court found EPA 
had erred in not setting MACT standards for every HAP emitted from a 
source. Therefore, with the exception of PM as a surrogate for HAP 
metals, in this action we are proposing emission limits for all HAP 
emitted from Mineral Wool and Wool Fiberglass. We note that we have 
established through previous analyses upheld by the court \6\ that PM 
is an appropriate surrogate for HAP metals, therefore, we retain that 
surrogacy relationship in these proposed rules.
---------------------------------------------------------------------------

    \4\ Cement Kiln Recycling Coalition v. EPA, 255 F.3d 855 (DC 
Cir. 2001) (per curiam).
    \5\ National Lime Ass'n v. EPA, 233 F.3d 625 (DC Cir. 2000).
    \6\ Sierra Club v. EPA, 353 F. 3d 976 (DC Cir. 2004).
---------------------------------------------------------------------------

    In separate litigation, the Court vacated portions of two 
provisions in EPA's CAA section 112 regulations that govern emissions 
of HAP during periods of SSM.\7\ Specifically, the Court vacated the 
SSM exemption contained in 40 CFR 63.6(f)(1) and 63.6(h)(1) that are 
part of regulations commonly referred to as the GP rule. When 
incorporated into section 112(d) regulations for specific source 
categories, these two provisions exempt sources from the requirement to 
comply with otherwise applicable MACT standards during periods of SSM. 
Because both of the Mineral Wool and Wool Fiberglass NESHAP relied on 
the GP rule for startup and shutdown provisions (40 CFR 63.1194 and 
63.1386(c)), we are also proposing to revise these provisions for both 
of the Mineral Wool and Wool Fiberglass source categories.
---------------------------------------------------------------------------

    \7\ Sierra Club v. EPA, 551 F. 3d 1019 (DC Cir. 2008), cert. 
denied, 130 S. Ct 1735 (2010).
---------------------------------------------------------------------------

    Recent litigation \8\ led to a consent decree under which we must 
propose these amendments no later than October 31, 2011; and promulgate 
no later than June 29, 2012.
---------------------------------------------------------------------------

    \8\ Consent Decree, Sierra Club v. Jackson (No. 09-cv-00152SBA, 
N.D. Cal., Sept. 27, 2010).
---------------------------------------------------------------------------

IV. Mineral Wool and Wool Fiberglass Source Categories

A. Overview of the Mineral Wool Production Source Category and MACT 
Standards

    The NESHAP (or MACT rule) for the Mineral Wool Production source 
category was promulgated on June 1, 1999 (64 FR 29490), and codified at 
40 CFR part 63, subpart DDD. As promulgated in 1999, the NESHAP applies 
to affected sources of HAP emissions at mineral wool production 
facilities. As defined in the 1992 EPA report, ``Documentation for 
Developing the Initial Source Category List'' (EPA-450/3/91/030, July 
1992), a ``mineral wool facility'' is ``any facility engaged in 
producing mineral wool fiber from slag, rock or other materials, 
excluding sand or glass.''
    The MACT rule for the Mineral Wool Production source category does 
not apply to facilities that manufacture wool fiberglass from sand, 
feldspar, sodium sulfate, anhydrous borax, boric acid or other similar 
materials.\9\ Although there

[[Page 72776]]

are some similarities among rock that may be used for both mineral wool 
and wool fiberglass production, the two industries are distinct. 
Mineral wool is used in cases in which fireproofing, structural 
strength and sound attenuation are needed, such as in high occupancy 
commercial and industrial buildings. Wool fiberglass is used primarily 
for insulation, in residential and small commercial buildings. Some 
wool fiberglass facilities also operate a ceiling tile or pipe product 
manufacturing line. The manufacturing of ceiling tile is not regulated 
under the Wool Fiberglass Manufacturing MACT Standard.
---------------------------------------------------------------------------

    \9\ Wool fiberglass produced from sand, feldspar, sodium 
sulfate, anhydrous borax, boric acid, etc. are a part of the wool 
fiberglass source category, which is also addressed in this action.
---------------------------------------------------------------------------

    Today, there are seven mineral wool facilities that are subject to 
the MACT rule. No new mineral wool facilities have been built in the 
last 21 years and the agency does not anticipate new mineral wool 
facilities will be built in the foreseeable future. According to the 
size definition applied to this industry by the U.S. SBA (750 company 
employees or less), 5 of the 7 firms, employing 540 employees 
altogether, are classified as a small business.
    Mineral wool is a fibrous, glassy substance consisting of silicate 
fibers typically 4 to 7 micrometers in diameter, made from natural rock 
(such as basalt, granite and other rock), blast furnace slag, glass 
cullet, coke and other similar materials. Products made from mineral 
wool are widely used in thermal and acoustical insulation and other 
products where mineral wool fiber is added to impart structural 
strength or fire resistance. In the mineral wool manufacturing process, 
raw materials (e.g., rock and slag) are melted in a cupola using coke 
as fuel; the molten material is then formed into fiber. In the 
production of mineral wool products that do not require high rigidity, 
oil is typically applied to suppress dust and add some strength to the 
fiber; the fiber is then sized and bagged or baled. This is known as a 
``nonbonded'' product which is manufactured on a ``nonbonded'' 
production line.
    For mineral wool products requiring a higher structural rigidity, 
typically a phenol/formaldehyde binder may be applied to the fiber. The 
binder-laden fiber mat is then thermoset in a curing oven and cooled. 
This is known as a ``bonded'' product which is made on a ``bonded 
product'' line. The major differences between the ``nonbonded'' and 
``bonded'' production lines are the application of binder during fiber 
collection and the use of a curing oven. Four facilities only 
manufacture nonbonded products, while the other three facilities 
operate both bonded and nonbonded production lines. A total of 11 
cupolas and 3 curing ovens are operated by the facilities in this 
source category.
    HAP emission sources at mineral wool production facilities include 
the cupola where the mineral charge is melted; a collection chamber, in 
which air and a binder are drawn over the fibers, forming them into a 
mat against a screen; and a curing oven that bonds the fibers (for 
bonded products). HAP are emitted from the cupolas, curing ovens and 
collection operations when collection occurs with curing. Collection at 
nonbonded product lines does not emit HAP. COS accounts for the 
majority of the HAP emissions from these facilities (approximately 224 
tpy and 51 percent of the total HAP emissions by mass). The majority of 
HAP emissions (approximately 58 percent of the total HAP by mass, 
including HF and HCl are from the cupolas. The remainder of the HAP are 
from bonded lines, including phenol, formaldehyde, and methanol. 
Although the majority of HAP are emitted from the cupola, the emissions 
(primarily formaldehyde and phenol) that were significant in evaluating 
risk are from the collection chambers on the bonded lines. Formaldehyde 
and phenol are emitted only from bonded mineral wool production lines; 
these lines include emissions from the application of the binder during 
collection and curing.
    The current NESHAP requires control of PM emissions, as a surrogate 
for HAP metals, from the cupolas and formaldehyde emissions from the 
curing ovens. Fabric filters are the control devices used by this 
industry to reduce both PM and HAP metal emissions from cupolas. 
Emissions from collection operations are not regulated under the 
current NESHAP, but collection and curing ovens are generally 
controlled using RTOs and fabric filters.
    The existing MACT rule applies to each existing, new and 
reconstructed cupola or curing oven in a mineral wool production 
facility. All mineral wool production facilities that are major sources 
are subject to the standards. For all cupolas, the 1999 MACT rule 
specifies a numerical emission limit for PM, as a surrogate for metal 
HAP. For new and reconstructed cupolas, emissions limits are specified 
for CO, as a surrogate for COS. Emissions limits for formaldehyde are 
also specified (as a surrogate for phenol emissions) for each existing, 
new, and reconstructed curing oven. Under the 1999 MACT rule, a mineral 
wool production facility may elect to comply with a numerical 
formaldehyde or CO emission limit expressed in mass of emissions per 
unit of production (kg/MG of melt or lb/ton of melt) or a percent 
reduction standard. PM emissions from existing, new, and reconstructed 
cupolas are limited to an outlet concentration of 0.05 kg/Mg (0.10 lb/
ton) of melt, 40 CFR 63.1178(a). CO emissions limits from new and 
reconstructed cupolas are limited to an outlet concentration of 0.05 
kg/Mg (0.10 lb/ton) of melt or 99 percent CO removal, 40 CFR 
63.1178(a). Formaldehyde emissions limits from existing, new, and 
reconstructed curing ovens are limited to an outlet concentration of 
0.03 kg/Mg (0.06 lb/ton) of melt or 80 percent formaldehyde removal, 40 
CFR 63.1179(a).

B. Overview of the Wool Fiberglass Manufacturing Source Category and 
1999 MACT Rule

    The NESHAP (or MACT rule) for the Wool Fiberglass Manufacturing 
source category was promulgated on June 14, 1999 (62 FR 31695), and 
codified at 40 CFR part 63, subpart NNN. As promulgated in 1999, the 
MACT rule applies to affected sources of HAP emissions at wool 
fiberglass manufacturing facilities. Although the source category 
definition includes all manufacturers of wool fiberglass, the 1999 MACT 
rule (40 CFR 63.1381) defines a ``wool fiberglass manufacturing 
facility'' as ``any facility manufacturing wool fiberglass on a RS 
manufacturing line producing bonded building insulation or on a FA 
manufacturing line producing bonded pipe insulation and bonded heavy-
density products.'' The MACT rule for the Wool Fiberglass Manufacturing 
source category does not apply to facilities that manufacture mineral 
wool from rock, slag, and other similar materials. In addition, RS and 
FA manufacturing lines that produce nonbonded products (in which no 
phenol-formaldehyde binder is applied) are not subject to the current 
standards.
    Wool fiberglass products are primarily used as thermal and 
acoustical insulation for buildings, automobiles, aircraft, appliances, 
ductwork and pipes. Other uses include liquid and air filtration. 
Approximately 90 percent of the wool fiberglass currently produced is 
used for residential and commercial building insulation products. 
Today, wool fiberglass is currently manufactured in the United States 
by 5 companies operating 29 facilities across 16 states. According to 
the size definition applied to this industry by the U.S. SBA (750 
company employees or less), none of these companies are classified as a 
small business. One new wool fiberglass facility was recently built in 
2007 and one wool fiberglass facility closed in 2010. Because several

[[Page 72777]]

furnaces have been idled across the industry, current production of 
wool fiberglass is below production levels from previous years, and 
several months of stockpiled products exist at wool fiberglass 
companies, we do not expect new wool fiberglass facilities to be built 
in the near future.
    Wool fiberglass is manufactured in a process that forms thin fibers 
from molten glass. Over 90 percent of the wool fiberglass industry 
produces insulation; two plants also operate a pipe product line and 
one plant operates a ceiling tile line (although the production of 
ceiling tile is not part of this MACT standard). A typical wool 
fiberglass manufacturing line consists of the following processes: (1) 
Heating of raw materials and/or cullet in a furnace to a molten state, 
(2) preparation of molten glass for fiberization, (3) formation of 
fibers into a wool fiberglass mat or pipe insulation product, (4) 
curing the binder-coated fiberglass mat, (5) cooling the mat (this 
process is not always present), and (6) backing, cutting, and 
packaging.
    The primary component of most types of wool fiberglass is silica 
sand, but wool fiberglass also includes varying quantities of feldspar, 
sodium sulfate, anhydrous borax, boric acid, and may be made entirely 
of glass cullet, crushed recycled glass. Wool fiberglass manufacturing 
plants typically operate one or more manufacturing lines. Refined raw 
materials for the glass batch are weighed, mixed, and conveyed to the 
glass-melting furnace, which may be gas-fired, electric, oxygen-
enriched or a combination of gas and electric.
    Two methods of forming fibers are used by the industry, RS and FA. 
In the RS process, centrifugal force causes molten glass to flow 
through small holes in the wall of a rapidly rotating cylinder. In the 
FA process, molten glass flows by gravity from a small furnace, or pot, 
to form threads that are then attenuated (stretched to the point of 
breaking) with air and/or flame.
    After the fibers are formed, they are sprayed with a binder to hold 
the fibers together. These bonded fibers are then collected as a mat on 
a conveyor. Binder compositions vary with product type. At the time of 
development of the MACT standard, wool fiberglass mat was typically 
made using a phenol-formaldehyde resin based binder. According to the 
trade organization, only a few insulation products are currently made 
using a formaldehyde-based binder because new formaldehyde- and HAP-
free binder formulations have been developed in recent years.\10\ Most 
new binder formulations are now HAP-free. According to the information 
collected through a survey by the industry, a few pipe insulation 
products made from wool fiberglass are still made at two facilities 
using a phenol-formaldehyde based binder.
---------------------------------------------------------------------------

    \10\ Letter from the North American Insulation Manufacturers 
Association (NAIMA). June 8, 2011 Letter.
---------------------------------------------------------------------------

    After application of the binder and formation of the mat, the 
conveyor carries the newly formed mat through an oven to cure the 
thermosetting resin and then through a cooling section. Some products, 
such as those made on FA manufacturing lines, do not require curing 
and/or cooling.
    Process emissions sources include the furnace where the charge is 
melted; the collection process, in which air carrying a binder is drawn 
over the fibers, forming them into a mat; and the curing oven that 
bonds the fibers (for bonded products only).
    HAP, including chromium compounds, are emitted from glass-melting 
furnaces. Glass-melting furnaces are constructed using refractory 
bricks or blocks (commonly called refractories), that provide thermal 
insulation and corrosion protection. The refractory bricks re-direct 
the heat of the furnace back into the melt. Refractories are produced 
to withstand the extreme corrosive thermal conditions of a furnace and 
may contain a variety of mineral materials, including chromium, and 
more specifically chromic oxide.\11\
---------------------------------------------------------------------------

    \11\ Chromium in Refractories. Sept. 2000. Dr. Mariano Velez, 
Ceramic Engineering Dept., Univ. Missouri-Rolla.
---------------------------------------------------------------------------

    In a wool fiberglass glass-melting furnace, sufficient temperatures 
are reached to drive the transformation of chromium from the trivalent 
to the hexavalent valence state. Because of the corrosive properties of 
the molten glass and the fining agents (salts added to the top of the 
molten glass layer which act to draw the gas bubbles out of the molten 
glass), the refractory of the inner furnace walls are eroded and fresh 
refractory is continually exposed along the metal/glass line within the 
furnace. As a result, when the glass-melting furnace is constructed 
using refractories containing high percentages of chromium, the 
emission levels of chromium compounds continuously increase over the 
life of the furnace according to the increasingly exposed refractory 
surface area.12 13 14
---------------------------------------------------------------------------

    \12\ Notes of April 14, 2011 telephone discussion between Carlos 
Davis, Environmental Manager, Certainteed, Kansas City, KS; and 
Susan Fairchild, project lead, USEPA/OAQPS/SPPD.
    \13\ Region 7 Certainteed, Kansas City, KS; meeting and site 
visit notes.
    \14\ Emissions Test Results from Certainteed, Kansas City, KS. 
2005 and 2008.
---------------------------------------------------------------------------

    In addition, organic HAP (formaldehyde, phenol, and methanol) may 
be released from RS forming and curing processes and FA forming and 
curing processes.
    The 1999 MACT rule applies to process emissions from each of the 
following existing, newly constructed, and reconstructed sources: 
Glass-melting furnaces located at a wool fiberglass manufacturing 
plant, RS manufacturing lines that produce building insulation, and FA 
manufacturing lines producing pipe insulation. The MACT rule also 
applies to FA manufacturing lines producing heavy-density products.
    The 1999 MACT rule requires control of PM emissions from the glass-
melting furnaces and formaldehyde emissions from the RS and FA lines. 
Typical control devices to reduce PM and HAP emissions from furnaces 
include both wet and dry ESP and fabric filters. Low and high-
temperature thermal oxidizers are used to control phenol, formaldehyde, 
and methanol from curing operations on bonded lines.
    The 1999 MACT rule limits PM emissions to an outlet concentration 
of 0.50 lb of PM per ton of glass pulled for both existing and new 
furnaces, 40 CFR 63.1382. Emissions of formaldehyde from RS 
manufacturing lines are limited to an outlet concentration of 1.2 lb/
ton of glass pulled for existing sources and 0.80 lb/ton of glass 
pulled for new sources. Emissions of formaldehyde from FA manufacturing 
lines producing pipe insulation are limited to an outlet concentration 
of 6.8 lb/ton of glass pulled from both existing and new sources, 40 
CFR 63.1382. Emissions of formaldehyde from FA manufacturing lines 
producing heavy-density products are limited to an outlet concentration 
of 7.8 lb/ton of glass pulled for new sources; no emission limit is 
specified for existing FA manufacturing lines producing heavy-density 
products, 40 CFR 63.1382. A surrogate approach, where PM serves as a 
surrogate for HAP metals and formaldehyde serves as a surrogate for 
organic HAP, was used in the 1999 MACT rule to allow for easier and 
less expensive testing and monitoring requirements.
    The industry trade association has advised us that because the wool

[[Page 72778]]

fiberglass industry has voluntarily phased out most uses of phenol-
formaldehyde based binders, there may now be only two wool fiberglass 
facilities that are subject to the current MACT rule. If this is 
accurate, 27 of the 29 facilities manufacturing wool fiberglass may not 
be considered major sources due to the phaseout of phenol-formaldehyde 
based binders. We are soliciting comment on our understanding that 
there will be no major sources in the wool fiberglass insulation source 
category (other than pipe insulation products) by the end of the 2012 
calendar year.

C. What data collection activities were conducted to support this 
action?

    In June 2010, the industry conducted a voluntary survey among all 
companies that own and operate mineral wool production and wool 
fiberglass manufacturing facilities. The survey sought test data for 
PM, CO and HAP emissions and information on the process equipment, 
control devices, point and fugitive emissions, practices used to 
control point and fugitive emissions, and other aspects of facility 
operations. Facilities were asked to seek and obtain prior EPA approval 
where new test data for a subset of processes, control devices and 
operations would be submitted as representative of an untested subset 
of processes, control devices and operations. In addition, facilities 
were allowed, in lieu of conducting new testing and with prior EPA 
approval, to submit existing and well-documented test data that were 
representative of current operations using the recommended test methods 
in the industry survey. Furthermore, the EPA requested, and industry 
agreed, that a subset of the facilities that were thought to be 
representative of emission sources from both the mineral wool and wool 
fiberglass industries would conduct additional emissions testing for 
certain HAP from specific processes. The bases for representativeness 
included design type and size of process units or equipment; fuel type; 
operating temperatures; control devices; and raw material content. 
Facilities completed and submitted responses to the industry survey in 
the spring of 2011.
    In summary, the EPA received existing emissions test data from all 
7 mineral wool facilities and 26 of the 29 wool fiberglass facilities, 
with some facilities submitting data for multiple years. Mineral wool 
facilities provided existing test data on cupolas, curing ovens, and 
collection operations. Wool fiberglass facilities provided existing 
test data on one or more of the following emission sources: Glass-
melting furnaces, curing ovens, forming, and collection operations. 
Emissions test data provided by facilities in both source categories, 
including the emission unit and pollutant tested, varied widely by 
facility.
    The mineral wool industry included testing for most HAP metals, CO, 
PM and certain organic HAP (formaldehyde, phenol, methanol and COS). 
Pollutants tested for by the wool fiberglass manufacturing source 
category included most HAP metals, including chromium and hexavalent 
chromium, PM, formaldehyde, phenol and methanol. The EPA completed the 
dataset by assigning emission estimates from tested processes and their 
known production rates to the similar represented processes based on 
production rates at the untested processes. A copy of the dataset can 
be found in the docket to this proposed rule.
    The results of these emission tests were compiled into a database 
for each source category, which is available in the docket for this 
action.

V. Analyses Performed

A. How did we estimate risks posed by the source categories?

    The EPA conducted a risk assessment that provided estimates of (1) 
The MIR posed by the HAP emissions from the 7 mineral wool facilities 
and 29 wool fiberglass manufacturing facilities in the source 
categories, (2) the distribution of cancer risks within the exposed 
populations, (3) the total cancer incidence, (4) estimates of the 
maximum TOSHI for chronic exposures to HAP with the potential to cause 
chronic non-cancer health effects, (5) worst-case screening estimates 
of HQ for acute exposures to HAP with the potential to cause non-cancer 
health effects, and (6) an evaluation of the potential for adverse 
environmental effects. In June of 2009, the EPA's SAB conducted a 
formal peer review of the risk assessment methodologies used in its 
review of the document entitled, ``Risk and Technology Review 
Assessment Methodologies.'' \15\ We received the final SAB report on 
this review in May of 2010.\16\ Where appropriate, we have responded to 
the key messages from this review in developing the current risk 
assessment; we will be continuing our efforts to improve our 
assessments by incorporating updates based on the SAB recommendations 
as they are developed and become available. The risk assessment 
consisted of seven primary steps, as discussed below. The docket for 
this rulemaking contains the following document, which provides more 
information on the risk assessment inputs and models: Draft Residual 
Risk Assessment for the Mineral Wool Production and Wool Fiberglass 
Manufacturing Source Categories.
---------------------------------------------------------------------------

    \15\ U.S. EPA, 2009. Risk and Technology Review (RTR) Risk 
Assessment Methodologies: For Review by the EPA's Science Advisory 
Board with Case Studies--MACT I Petroleum Refining Sources and 
Portland Cement Manufacturing. EPA-452/R-09-006. Available at http://www.epa.gov/ttn/atw/rrisk/rtrpg.html.
    \16\ U.S. EPA, 2010. SAB's Response to EPA's RTR Risk Assessment 
Methodologies. Available at: http://yosemite.epa.gov/sab/
sabproduct.nsf/4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-
007-unsigned.pdf.
---------------------------------------------------------------------------

1. Establishing the Nature and Magnitude of Actual Emissions and 
Identifying the Emissions Release Characteristics
    For each facility in the Mineral Wool Production and Wool 
Fiberglass Manufacturing source categories, we developed and compiled 
an emissions profile (including emissions estimates, stack parameters, 
and location data) based on the information provided by the industry 
survey, the emissions test data, and various calculations. We used the 
production rates of tested processes to assign emissions to untested 
but similar processes based on known production rates at the untested 
processes. The site-specific emissions profiles include annual 
estimates of process emissions for the 2010 timeframe, as well as 
emissions release characteristics such as emissions release height, 
temperature, velocity, and location coordinates. We are requesting 
comment on the assumptions used to complete the dataset, including 
assumptions we made to assign emission rates.
    The primary risk assessment is based on estimates of the actual 
emissions (though we also analyzed allowable emissions and the 
potential risks due to allowable emissions). We received a substantial 
amount of emissions test data and other information from the industry 
survey that enabled us to derive estimates of stack emissions of 
certain HAP for all of the facilities in both source categories. The 
wool fiberglass industry provided emission testing on all known 
pollutants, including total chromium and hexavalent chromium, PM, and 
other metals at furnaces they considered to be representative of other 
furnaces operated by the company. Where different furnace types were 
used to melt fiberglass, industry usually tested representative 
furnaces for each furnace type. The representative furnaces were chosen 
by industry according to production rates and furnace type. For 
untested furnaces, industry provided

[[Page 72779]]

the normal operating rate in terms of tons of glass produced per hour. 
We estimated emissions at untested furnaces by using data from the 
representative tested furnaces. To do this, we used test data from 
representative furnaces that provided emissions rates of all tested 
pollutants on a pound per hour basis. We applied this pound per hour 
basis to the untested furnaces with the known production rates of those 
furnaces to estimate pounds per hour of pollutants. We considered 
furnace type and company when making these assignments.
    We consider these estimates to be very good because they are based 
upon known emission test methods, have test reports that verify the 
results, were signed as being true and accurate by authorized company 
representatives, and also signed as being accurate by the testing 
company. In addition, one testing company was used by the industry to 
conduct all the emissions testing using approved EPA methods. We are 
requesting comment on our use of the available test data to assign 
emission estimates to untested emission points.
2. Establishing the Relationship Between Actual Emissions and MACT-
Allowable Emissions Levels
    The emissions data in our data set consists of actual stack 
emissions and, where we did not have actual emissions data, estimates 
of emissions based on a subset of operations that were representative 
of such emission points. In the EPA's experience, with most source 
categories, we generally have found that ``actual'' emissions levels 
are lower than the emissions levels that a facility is allowed to emit 
under the MACT standards. The emissions levels allowed to be emitted by 
the MACT standards are referred to as the ``MACT-allowable'' emissions 
levels. This represents the highest emissions level that could be 
emitted by facilities without violating the MACT standards.
    As we discussed in prior residual risk and technology review rules, 
assessing the risks at the MACT-allowable level is reasonable since 
these risks reflect the maximum level at which sources could emit while 
still complying with the MACT standards. However, 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 (54 FR 38044, September 14, 1989). Considering actual 
emissions is reasonable because source categories typically seek to 
perform better than required by emissions standards to provide an 
operational cushion and to accommodate the variability in manufacturing 
processes and control device performance. Facilities' actual emissions 
may also be significantly lower than MACT-allowable emissions for other 
reasons such as State requirements, improvements in performance of 
control devices since by the MACT standards, or reduced production. In 
this case, we are reducing the allowable emissions limits to the levels 
of actual emissions. For this reason, for the pollutants emitted, we 
are using only actual emissions in our risk analysis.
    For both the Mineral Wool Production and Wool Fiberglass 
Manufacturing source categories, we evaluated actual and allowable 
stack emissions. Appendices 1a and 1b of the Draft Residual Risk 
Assessment for the Mineral Wool Production and Wool Fiberglass 
Manufacturing Source Categories, available in the docket, further 
describe the estimates of MACT-allowable emissions and the estimates of 
risks due to allowable emissions.
    a. Actual and allowable emissions for the Mineral Wool Production 
source category.
    The analysis of allowable emissions for the Mineral Wool Production 
source category was largely focused on formaldehyde emissions, which we 
considered the most important HAP emitted from this source category 
based on our screening level risk assessment and the HAP for which we 
had the most data. However, we also considered allowable emissions for 
other HAP, including HAP metals and COS. To estimate the difference 
between the actual and allowable emissions, we averaged the actual 
formaldehyde emission rates of manufacturing lines provided by 
facilities and compared those values to the maximum level allowed by 
the existing MACT standard (i.e., 0.06 pounds of formaldehyde per ton 
of melt) from all curing ovens.
    We realize that these estimates of allowable emissions are 
theoretical high-end estimates as facilities must maintain average 
emissions levels at some level below the MACT limit to ensure 
compliance with the standard at all times because of the day-to-day 
variability in emissions. Nevertheless, these high-end estimates of 
allowable emissions were adequate for us to estimate the magnitude of 
allowable emissions and the differences between the estimates of actual 
emissions and the MACT allowable emissions.
    Based on this analysis, we conclude that all facilities in the 
mineral wool source category are emitting formaldehyde at levels lower 
than allowable and that the differences between actual and allowable 
emissions are significant. For the facilities producing bonded product, 
the estimated actual emissions were up to three times lower than 
allowable emissions. That is, MACT-allowable emissions were determined 
to be three times the actual emissions for all pollutants in the 
Mineral Wool Production category. Therefore, we multiplied the actual 
stack emissions from each facility by a factor of 3 to derive estimates 
of allowable emissions for modeling (whether these emissions were 
measured by testing or calculated based on representative emission 
tests).
    b. Analysis of allowable and actual emissions for the Wool 
Fiberglass Manufacturing source category.
    The analysis of allowable emissions for the Wool Fiberglass 
Manufacturing source category was largely focused on emissions of 
chromium compounds and formaldehyde because these are the only 
pollutants emitted with significant health risks. To estimate the 
difference between the actual and allowable emissions, we averaged the 
actual formaldehyde emission rates of manufacturing lines provided by 
facilities and compared those values to the maximum level allowed by 
the existing MACT standard (i.e., 1.2 or 0.8 lb/ton of glass pulled for 
formaldehyde).
    We realize that these estimates of allowable emissions are 
theoretical high-end estimates as facilities must maintain average 
emissions levels at some level below the MACT limit to ensure 
compliance with the standard at all times because of the day-to-day 
variability in emissions. Nevertheless, these high-end estimates of 
allowable emissions were adequate for us to estimate the magnitude of 
allowable emissions and the differences between the estimates of actual 
emissions and the MACT allowable emissions. Based on this analysis, we 
conclude that allowable emissions are estimated to be three times 
higher than actual emissions. Therefore, to develop the MACT-allowable 
emissions, the actual stack emissions for formaldehyde, phenol and 
methanol were multiplied by a factor of 3. The range of differences 
between actual and allowable formaldehyde emission levels is 
significant, that is, for some sources there was little difference 
between actual and allowable emission levels, other times, allowable 
emissions were up to 5 times greater than actual emissions. MACT-
allowable emissions for chromium compounds were determined to be equal 
to actual emissions since there is currently no

[[Page 72780]]

emissions limit for chromium compounds.
3. Conducting Dispersion Modeling, Determining Inhalation Exposures, 
and Estimating Individual and Population Inhalation Risks
    Both long-term and short-term inhalation exposure concentrations 
and health risks from each source in both the source categories 
addressed in this proposal were estimated using the HEM (Community and 
Sector HEM-3 version 2.1 Beta). The HEM-3 performs three primary risk 
assessment activities: (1) Conducting dispersion modeling to estimate 
the concentrations of HAP in ambient air, (2) estimating long-term and 
short-term inhalation exposures to individuals residing within 50 km of 
the modeled sources, and (3) estimating individual and population-level 
inhalation risks using the exposure estimates and quantitative dose-
response information.
    The dispersion model used by HEM-3 is AERMOD, which is one of the 
EPA's preferred models for assessing pollutant concentrations from 
industrial facilities.\17\ HEM-3 draws on three data libraries to 
perform the dispersion modeling and to develop the preliminary risk 
estimates. The first is a library of meteorological data, which is used 
for dispersion calculations. This library includes 1 year of hourly 
surface and upper air observations for more than 200 meteorological 
stations, selected to provide coverage of the United States and Puerto 
Rico. A second library of United States Census Bureau census block \18\ 
internal point locations and populations provides the basis of human 
exposure calculations (Census, 2000). In addition, for each census 
block, the Census library includes the elevation and controlling hill 
height, which are used in dispersion calculations. A third library of 
pollutant unit risk factors and other health benchmarks is used to 
estimate health risks. These risk factors and health benchmarks are the 
latest values recommended by the EPA for HAP and other toxic air 
pollutants. These values are available at http://www.epa.gov/ttn/atw/toxsource/summary.html and are discussed in more detail later in this 
section.
---------------------------------------------------------------------------

    \17\ U.S. EPA. Revision to the Guideline on Air Quality Models: 
Adoption of a Preferred General Purpose (Flat and Complex Terrain) 
Dispersion Model and Other Revisions (70 FR 68218, November 9, 
2005).
    \18\ A census block is generally the smallest geographic area 
for which census statistics are tabulated.
---------------------------------------------------------------------------

    In developing the risk assessment for chronic exposures, we used 
the estimated annual average ambient air concentration of each of the 
HAP emitted by each source for which we have emissions data in the 
source category. The air concentrations at each nearby census block 
centroid were used as a surrogate for the chronic inhalation exposure 
concentration for all the people who reside in that census block. We 
calculated the MIR for each facility as the cancer risk associated with 
a continuous lifetime exposure (24 hours per day, 7 days per week, and 
52 weeks per year for a 70-year period) to the maximum concentration at 
the centroid of an inhabited census block. Individual cancer risks were 
calculated by multiplying the estimated lifetime exposure to the 
ambient concentration of each of the HAP (in micrograms per cubic 
meter) by its URE, which is an upper bound estimate of an individual's 
probability of contracting cancer over a lifetime of exposure to a 
concentration of 1 microgram of the pollutant per cubic meter of air. 
For residual risk assessments, we generally use URE values from the 
EPA's Integrated Risk Information System (IRIS). For carcinogenic 
pollutants without an EPA IRIS value, we look to other reputable 
sources of cancer dose-response values, often using CalEPA URE values, 
where available. We may use dose-response values in place of or in 
addition to other values, if appropriate, in cases where new, 
scientifically credible dose-response values have been developed in a 
manner consistent with the EPA guidelines and have undergone a peer 
review process similar to that used by the EPA.
    With regard to formaldehyde, the EPA determined in 2004 that the 
CIIT cancer dose-response value for formaldehyde (5.5 x 
10-\9\ per [mu]g/m\3\) was based on better science than the 
IRIS cancer dose-response value (1.3 x 10-\5\ per [mu]g/
m\3\) 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 the EPA returned to using the 1991 IRIS 
value. The EPA has been working on revising the formaldehyde IRIS 
assessment and the NAS completed its review of the EPA's draft in May 
of 2011. The EPA is reviewing the public comments and the NAS 
independent scientific peer review. 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. The draft IRIS assessment 
will be revised in response to the NAS peer review and public comments 
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. As described in the risk assessment, the IRIS URE for 
formaldehyde is 1.3 x 10-\5\ [mu]g/m\3\, whereas, the CIIT 
URE for formaldehyde is 5.5 x 10-\9\ [mu]g/m\3\.
    Incremental individual lifetime cancer risks associated with 
emissions from the source category were estimated as the sum of the 
risks for each of the carcinogenic HAP (including those classified as 
carcinogenic to humans, likely to be carcinogenic to humans and 
suggestive evidence of carcinogenic potential \19\) emitted by the 
modeled source. Cancer incidence and the distribution of individual 
cancer risks for the population within 50 km of any source were also 
estimated for the source category as part of these assessments by 
summing individual risks. A distance of 50 km is consistent with both 
the analysis supporting the 1989 Benzene NESHAP (54 FR 38044) and the 
limitations of Gaussian dispersion models, including AERMOD.
---------------------------------------------------------------------------

    \19\ These classifications also coincide with the terms ``known 
carcinogen, probable carcinogen and possible carcinogen,'' 
respectively, which are the terms advocated in the EPA's previous 
Guidelines for Carcinogen Risk Assessment, published in 1986 (51 FR 
33992, September 24, 1986). Summing the risks of these individual 
compounds to obtain the cumulative cancer risks is an approach that 
was recommended by the EPA's SAB in their 2002 peer review of EPA's 
NATA entitled, NATA--Evaluating the National-scale Air Toxics 
Assessment 1996 Data--an SAB Advisory, available at: http://
yosemite.epa.gov/sab/sabproduct.nsf/
214C6E915BB04E14852570CA007A682C/$File/ecadv02001.pdf.
---------------------------------------------------------------------------

    To assess risk of noncancer health effects from chronic exposures, 
we summed the HQ for each of the HAP that affects a common target organ 
system to obtain the HI for that target organ system (or TOSHI). The HQ 
for chronic exposures is the estimated chronic exposure divided by the 
chronic reference level, which is either the EPA RfC, defined as ``an 
estimate (with uncertainty spanning perhaps an order of magnitude) of a 
continuous inhalation exposure to the human population (including 
sensitive subgroups) that is likely to be without an appreciable risk 
of deleterious effects

[[Page 72781]]

during a lifetime,'' or, in cases where an RfC from the EPA's IRIS 
database is not available, the EPA will utilize the following 
prioritized sources for our chronic dose-response values: (1) The 
Agency for Toxic Substances and Disease Registry Minimum Risk Level, 
which is defined as ``an estimate of daily human exposure to a 
substance that is likely to be without an appreciable risk of adverse 
effects (other than cancer) over a specified duration of exposure''; 
(2) the CalEPA Chronic REL, which is defined as ``the concentration 
level at or below which no adverse health effects are anticipated for a 
specified exposure duration''; and (3), as noted above, in cases where 
scientifically credible dose-response values have been developed in a 
manner consistent with the EPA guidelines and have undergone a peer 
review process similar to that used by the EPA, we may use those dose-
response values in place of or in concert with other values.
    Screening estimates of acute exposures and risks were also 
evaluated for each of the HAP at the point of highest off-site exposure 
for each facility (i.e., not just the census block centroids), assuming 
that a person is located at this spot at a time when both the peak 
(hourly) emission rate and worst-case dispersion conditions (1991 
calendar year data) occur. The acute HQ is the estimated acute exposure 
divided by the acute dose-response value. In each case, acute HQ values 
were calculated using best available, short-term dose-response values. 
These acute dose-response values, which are described below, include 
the acute REL, AEGL and ERPG for 1-hour exposure durations. As 
discussed below, we used conservative assumptions for emission rates, 
meteorology and exposure location for our acute analysis.
    As described in the CalEPA's Air Toxics Hot Spots Program Risk 
Assessment Guidelines, Part I, The Determination of Acute Reference 
Exposure Levels for Airborne Toxicants, an acute REL value (http://www.oehha.ca.gov/air/pdf/acuterel.pdf) is defined as ``the 
concentration level at or below which no adverse health effects are 
anticipated for a specified exposure duration.'' Acute REL values are 
based on the most sensitive, relevant, adverse health effect reported 
in the medical and toxicological literature. Acute REL values 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 
acute REL does not automatically indicate an adverse health impact.
    AEGL values were derived in response to recommendations from the 
NRC. As described in Standing Operating Procedures of the National 
Advisory Committee on Acute Exposure Guideline Levels for Hazardous 
Substances (http://www.epa.gov/opptintr/aegl/pubs/sop.pdf),\20\ ``the 
NRC's previous name for acute exposure levels--community emergency 
exposure levels--was replaced by the term AEGL to reflect the broad 
application of these values to planning, response, and prevention in 
the community, the workplace, transportation, the military, and the 
remediation of Superfund sites.'' This document also states that AEGL 
values ``represent threshold exposure limits for the general public and 
are applicable to emergency exposures ranging from 10 minutes to 8 
hours.'' The document lays out the purpose and objectives of AEGL by 
stating (page 21) that ``the primary purpose of the AEGL program and 
the National Advisory Committee for Acute Exposure Guideline Levels for 
Hazardous Substances is to develop guideline levels for once-in-a-
lifetime, short-term exposures to airborne concentrations of acutely 
toxic, high-priority chemicals.'' In detailing the intended application 
of AEGL values, the document states (page 31) that ``[i]t is 
anticipated that the AEGL values will be used for regulatory and 
nonregulatory purposes by U.S. Federal and state agencies and possibly 
the international community in conjunction with chemical emergency 
response, planning and prevention programs. More specifically, the AEGL 
values will be used for conducting various risk assessments to aid in 
the development of emergency preparedness and prevention plans, as well 
as real-time emergency response actions, for accidental chemical 
releases at fixed facilities and from transport carriers.''
---------------------------------------------------------------------------

    \20\ NAS, 2001. Standing Operating Procedures for Developing 
Acute Exposure Levels for Hazardous Chemicals, page 2.
---------------------------------------------------------------------------

    The AEGL-1 value is then specifically defined as ``the airborne 
concentration 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.'' The document also notes (page 
3) that, ``Airborne concentrations below AEGL-1 represent exposure 
levels that can produce mild and progressively increasing but transient 
and nondisabling odor, taste, and sensory irritation or certain 
asymptomatic, nonsensory effects.'' Similarly, the document defines 
AEGL-2 values as ``the airborne concentration (expressed as ppm or mg/
m\3\) of a substance above which it is predicted that the general 
population, including susceptible individuals, could experience 
irreversible or other serious, long-lasting adverse health effects or 
an impaired ability to escape.''
    ERPG values are derived for use in emergency response, as described 
in the American Industrial Hygiene Association's document entitled, 
Emergency Response Planning Guidelines (ERPG) Procedures and 
Responsibilities (http://www.aiha.org/1documents/committees/ERPSOPs2006.pdf) which states that, ``Emergency Response Planning 
Guidelines were developed for emergency planning and are intended as 
health based guideline concentrations for single exposures to 
chemicals.'' \21\ The ERPG-1 value is defined 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.'' Similarly, the ERPG-2 value is defined 
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.''
---------------------------------------------------------------------------

    \21\ ERP Committee Procedures and Responsibilities. November 1, 
2006. American Industrial Hygiene Association.
---------------------------------------------------------------------------

    As can be seen from the definitions above, the AEGL and ERPG values 
include the similarly-defined severity levels 1 and 2. For many 
chemicals, a severity level 1 value AEGL or ERPG has not been 
developed; in these instances, higher severity level AEGL-2 or ERPG-2 
values are compared to our modeled exposure levels to screen for 
potential acute concerns.
    Acute REL values for 1-hour exposure durations are typically lower 
than their corresponding AEGL-1 and ERPG-1 values. Even though their 
definitions are slightly different, AEGL-1 values are often the same as 
the corresponding ERPG-1 values, and AEGL-2 values are often equal to 
ERPG-2 values. Maximum HQ values from our acute screening risk 
assessments typically result when basing them on the acute

[[Page 72782]]

REL value for a particular pollutant. In cases where our maximum acute 
HQ value exceeds 1, we also report the HQ value based on the next 
highest acute dose-response value (usually the AEGL-1 and/or the ERPG-1 
value).
    To develop screening estimates of acute exposures, we developed 
estimates of maximum hourly emission rates by multiplying the average 
actual annual hourly emission rates by a factor to cover routinely 
variable emissions. We chose the factor based on process knowledge and 
engineering judgment and with awareness of a Texas study of short-term 
emissions variability, which showed that most peak emission events, in 
a heavily-industrialized four county area (Harris, Galveston, Chambers 
and Brazoria Counties, Texas) were less than twice the annual average 
hourly emission rate. The highest peak emission event was 74 times the 
annual average hourly emission rate, and the 99th percentile ratio of 
peak hourly emission rate to the annual average hourly emission rate 
was 9.\22\ This analysis is provided in Appendix 4 of the Draft 
Residual Risk Assessment for the Mineral Wool Production and Wool 
Fiberglass Manufacturing Source Categories, which is available in the 
docket for this action. Considering this analysis, unless specific 
process knowledge or data are available to provide an alternate value, 
to account for more than 99 percent of the peak hourly emissions, we 
apply a conservative screening multiplication factor of 10 to the 
average annual hourly emission rate in these acute exposure screening 
assessments. The factor of 10 was used for the Wool Fiberglass 
Manufacturing source category, but we determined that a factor of 3 is 
more appropriate for the Mineral Wool Production source category (for 
more details see the Acute Effects Factor for Mineral Wool 
Manufacturing Operations document in the docket for this rulemaking).
---------------------------------------------------------------------------

    \22\ See http://www.tceq.state.tx.us/compliance/field_ops/eer/index.html or docket to access the source of these data.
---------------------------------------------------------------------------

    For the mineral wool source category, we used data from the highest 
formaldehyde emitting source among the mineral wool producers. That 
company also presented the highest risk due to formaldehyde emissions. 
This company provided the agency with 10 years of measurements of 
binder formulation, formaldehyde content in binders, binder application 
rates, and binder retention rates. Because the industry must 
manufacture their product for use in fireproofing, they must keep 
meticulous records of production specifics. These data are used to show 
compliance with Underwriters Laboratories and other building 
construction safety standards. From this specific 10-year data set, the 
EPA determined that, on a worst-case possible basis, formaldehyde could 
be emitted at levels no more than three times the actual rate. The 
worst-case scenario is possible if the binder contained the maximum 
amount of resin possible, the resin contained the maximum amount of 
formaldehyde possible, was sprayed at the maximum rate possible, and 
retained in the product at the minimum level possible. These data were 
used to in the risk assessment to determine the acute health effects 
hazard index. For Mineral Wool Production, the plant-specific acute 
factors were calculated and ranged from 1.0 to 1.6. Based on these 
results, and to allow for additional uncertainty in emissions, we used 
an acute factor of 3.0. The calculation we used to determine this acute 
factor is available in the docket to this rule.\23\
---------------------------------------------------------------------------

    \23\ Acute Factor Memo. Cindy Hancy and David Reeves, RTI; to 
Susan Fairchild, USEPA/OAQPS/SPPD; EPA Project Lead. August 30, 
2011.
---------------------------------------------------------------------------

    In cases where acute HQ values from the screening step were less 
than or equal to 1, acute impacts were deemed negligible and no further 
analysis was performed. In cases where an acute HQ from the screening 
step was greater than 1, additional site-specific data were considered 
to develop a more refined estimate of the potential for acute impacts 
of concern. The data refinements employed for these source categories 
consisted of using the site-specific facility layout to distinguish 
facility property from an area where the public could be exposed. These 
refinements are discussed in the draft risk assessment document, which 
is available in the docket for each of these source categories. 
Ideally, we would prefer to have continuous measurements over time to 
see how the emissions vary each hour over an entire year. Having a 
frequency distribution of hourly emission rates over a year would allow 
us to perform a probabilistic analysis to estimate potential threshold 
exceedances and their frequency of occurrence. Such an evaluation could 
include a more complete statistical treatment of the key parameters and 
elements adopted in this screening analysis. However, we recognize that 
having this level of data is rare, hence our use of the multiplier 
approach.
    To better characterize the potential health risks associated with 
estimated worst-case acute exposures to HAP, and in response to a key 
recommendation from the SAB's peer review of EPA's RTR risk assessment 
methodologies,\24\ we examine a wider range of available acute health 
metrics than we do for our chronic risk assessments. This is in 
response to the acknowledgement that there are generally more data gaps 
and inconsistencies in acute reference values than there are in chronic 
reference values. By definition, the acute CA-REL represents a health-
protective level of exposure, with no risk anticipated below those 
levels, even for repeated exposures; however, the health risk from 
higher-level exposures is unknown. Therefore, when a CA-REL is exceeded 
and an AEGL-1 or ERPG-1 level is available (i.e., levels at which mild 
effects are anticipated in the general public for a single exposure), 
we have used them as a second comparative measure. Historically, 
comparisons of the estimated maximum off-site one-hour exposure levels 
have not been typically made to 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 since they are designed to protect the worker 
population (presumed healthy adults) for short duration (< 15 minute) 
increases in exposure.\25\ 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 (U.S. EPA 2009). Such is not the case when 
comparing the available acute inhalation health effect reference values 
for formaldehyde (U.S. EPA 2009).
---------------------------------------------------------------------------

    \24\ The SAB Peer review of RTR Risk Assessment Methodoligies is 
available at: http://yosemite.epa.gov/sab/sabproduct.nsf/
4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-007-unsigned.pdf.
    \25\ U.S. EPA. (2009) Chapter 2.9 Chemical Specific Reference 
Values for Formaldehyde in Graphical Arrays of Chemical-Specific 
Health Effect Reference Values for Inhalation Exposures (Final 
Report). U.S. Environmental Protection Agency, Washington, DC, EPA/
600/R-09/061, and available on-line at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=211003.
---------------------------------------------------------------------------

    The worst-case maximum estimated 1-hour exposure to formaldehyde 
outside the facility fence line for the mineral wool source category is 
0.47 mg/m\3\. This estimated worst-case exposure exceeds the 1-hour REL 
by a factor of 8 (HQREL = 8) and is below the 1-hour AEGL-1 
(HQAEGL-1 = 0.4). This exposure estimate does not exceed the 
AEGL-1, or exceed the workplace ceiling level guideline for the 
formaldehyde value developed by the

[[Page 72783]]

NIOSH \26\ ``for any 15 minute period in a work day'' (NIOSH REL-
ceiling value of 0.12 mg/m\3\; HQNIOSH = 4). The estimate is 
at the value developed by the ACGIH as ``not to be exceeded at any 
time'' (ACGIH TLV-ceiling value of 0.37 mg/m\3\; HQACGIH = 
1). Additionally, the estimated maximum acute exposure exceeds the Air 
Quality Guideline value that was developed by the World Health 
Organization \27\ for 30-minute exposures (0.1 mg/m\3\; 
HQWHO = 5).
---------------------------------------------------------------------------

    \26\ National Institutes for Occupational Saffety and Health 
(NIOSH). Occupational Safety and Health Guideline for Formaldehyde; 
http://www.cdc.gov/niosh/docs/81-123/pdfs/0293.pdf.
    \27\ WHO (2000). Chapter 5.8 Formaldehyde, in Air Quality 
Guidelines for Europe, second edition. World Health Organization 
Regional Publications, European Series, No. 91. Copenhagen, Denmark. 
Available on-line at http://www.euro.who.int/_data/assets/pdf_file/0005/74732/E71922.pdf.
---------------------------------------------------------------------------

    For the wool fiberglass manufacturing source category, the worst-
case maximum estimated 1-hour exposure to formaldehyde outside the 
facility fence line is 1.92 mg/m\3\. This estimated worst-case exposure 
exceeds the 1-hour REL by a factor of 30 (HQREL = 30) and 
the 1-hour AEGL-1 (HQAEGL-1 = 2). This exposure estimate 
also exceeds multiple workplace ceiling level guidelines for 
formaldehyde, including the value developed by the American Conference 
of Governmental Industrial Hygienists (ACGIH) as ``not to be exceeded 
at any time'' (ACGIH TLV-ceiling value of 0.37 mg/m\3\; 
HQACGIH = 5), and the value developed by the National 
Institutes for Occupational Safety and Health (NIOSH) ``for any 15 
minute period in a work day'' (NIOSH REL-ceiling value of 0.12 mg/m\3\; 
HQNIOSH = 16). Additionally, the estimated maximum acute 
exposure exceeds the Air Quality Guideline value that was developed by 
the World Health Organization \28\ for 30-minute exposures (0.1 mg/
m\3\; HQWHO = 19). Id.
---------------------------------------------------------------------------

    \28\ WHO (2000). Chapter 5.8 Formaldehyde, In Air Quality 
Guidelinies for Europe, second edition. World Health Organization 
Regional Publications, European Series, No. 91. Copenhagen, Denmark. 
Available on-line at http://www.euro.who.int_data/assets/pdf_file/0005/74732/E71922.pdf.
---------------------------------------------------------------------------

    We solicit comment on the use of the occupational values described 
above in the interpretation of these worst-case acute screening 
exposure estimates for both the Mineral Wool Production and Wool 
Fiberglass Manufacturing source categories.
4. Conducting Multipathway Exposure and Risk Modeling
    The potential for significant human health risks due to exposures 
via routes other than inhalation (i.e., multi-pathway exposures) and 
the potential for adverse environmental impacts were evaluated in a 
three-step process. In the first step, we determined whether any 
facilities emitted any PB-HAP in the environment. There are 14 PB-HAP 
compounds or compound classes identified for this screening in the 
EPA's Air Toxics Risk Assessment Library (available at http://www.epa.gov/ttn/fera/risk_atra_vol1.html). They are cadmium 
compounds, chlordane, chlorinated dibenzodioxins and furans, 
dichlorodiphenyldichloroethylene, heptachlor, hexachlorobenzene, 
hexachlorocyclohexane, lead compounds, mercury compounds, methoxychlor, 
polychlorinated biphenyls, polycyclic organic matter, toxaphene and 
trifluralin.
    Since three of these PB-HAP (lead, cadmium, and mercury compounds) 
are emitted by at least one facility in both source categories, we 
proceeded to the second step of the evaluation. In this step, we 
determined whether the facility-specific emission rates of each of the 
emitted PB-HAP were large enough to create the potential for 
significant non-inhalation human or environmental risks under 
reasonable worst-case conditions. To facilitate this step, we developed 
emission rate thresholds for each PB-HAP using a hypothetical worst-
case screening exposure scenario developed for use in conjunction with 
the EPA's TRIM.FaTE model. The hypothetical screening scenario was 
subjected to a sensitivity analysis to ensure that its key design 
parameters were established such that environmental media 
concentrations were not underestimated (i.e., to minimize the 
occurrence of false negatives or results that suggest that risks might 
be acceptable when, in fact, actual risks are high) and to also 
minimize the occurrence of false positives for human health endpoints. 
We call this application of the TRIM.FaTE model TRIM-Screen. The 
facility-specific emission rates of each of the PB-HAP in each source 
category were compared to the TRIM-Screen emission threshold values for 
each of the PB-HAP identified in the source category datasets to assess 
the potential for significant human health risks or environmental risks 
via non-inhalation pathways.
    None of the facilities in the Mineral Wool Production and Wool 
Fiberglass Manufacturing source categories reported emissions of PB-HAP 
that were greater than the de minimis threshold levels, indicating no 
potential for significant multi-pathway risks from these facilities. 
Therefore, multi-pathway exposures and environmental risks were deemed 
negligible and no further analysis was performed. This analysis is 
provided in the Draft Residual Risk Assessment for the Mineral Wool 
Production and Wool Fiberglass Manufacturing Source Categories, which 
is available in the docket for this action.
5. Assessing Risks After Control Options
    In addition to assessing baseline inhalation risks and screening 
for potential multi-pathway risks, where appropriate, we also estimated 
risks considering the potential emission reductions that would be 
achieved by the particular control options under consideration. In 
these cases, the expected emissions reductions were applied to the 
specific HAP and emissions sources in the source category dataset to 
develop corresponding estimates of risk reductions. More information on 
the risks remaining after controls are in place to meet the emissions 
limits is available in the Draft Residual Risk Assessment for the 
Mineral Wool Production and Wool fiberglass Manufacturing Source 
Categories, which is available in the docket for this action.
6. Conducting Facility Wide Risk Assessments
    To put the source category risks in context, we also examine the 
risks from the entire ``facility,'' where the facility includes all 
HAP-emitting operations within a contiguous area and under common 
control. In other words, for each facility that includes one or more 
sources from one of the source categories under review, we examine the 
HAP emissions not only from the source category of interest, but also 
from all other emission sources at the facility. For both source 
categories, all significant HAP sources have been included in the 
source category risk analysis and there are no other significant HAP 
emissions sources present. Therefore, we conclude that the facility 
wide risk is essentially the same as the source category risk for both 
the mineral wool and wool fiberglass source categories and that no 
separate facility wide analysis is necessary.
7. Considering Uncertainties in Risk Assessment
    Uncertainty and the potential for bias are inherent in all risk 
assessments, including those performed for the source categories 
addressed in this proposal. Although uncertainty exists, we believe 
that our approach, which uses conservative tools and assumptions, 
ensures that our decisions are health-protective. A brief discussion of 
the uncertainties in the emissions datasets, dispersion modeling, 
inhalation exposure estimates and dose-

[[Page 72784]]

response relationships follows below. A more thorough discussion of 
these uncertainties is included in the draft risk assessment 
documentation (referenced earlier) available in the docket for this 
action.
a. Uncertainties in the Emissions Datasets
    Although the development of the MACT datasets involved quality 
assurance/quality control processes, the accuracy of emissions values 
will vary depending on the source of the data, the degree to which data 
are incomplete or missing, the degree to which assumptions made to 
complete the datasets are inaccurate, errors in estimating emissions 
values and other factors. The emission estimates considered in this 
analysis generally are annual totals for certain years that do not 
reflect short-term fluctuations during the course of a year or 
variations from year to year.
    The estimates of peak hourly emission rates for the acute effects 
screening assessment were based on a multiplication factor of 10 
applied to the average annual hourly emission rate, which is intended 
to account for emission fluctuations due to normal facility operations.
b. Uncertainties in Dispersion Modeling
    While the analysis employed the EPA's recommended regulatory 
dispersion model, AERMOD, we recognize that there is uncertainty in 
ambient concentration estimates associated with any model, including 
AERMOD. In circumstances where we had to choose between various model 
options, where possible, model options (e.g., rural/urban, plume 
depletion, chemistry) were selected to provide an overestimate of 
ambient air concentrations of the HAP rather than underestimates. 
However, because of practicality and data limitation reasons, some 
factors (e.g., meteorology, building downwash) have the potential in 
some situations to overestimate or underestimate ambient impacts. For 
example, meteorological data were taken from a single year (1991) and 
facility locations can be a significant distance from the site where 
these data were taken. Despite these uncertainties, we believe that the 
approach considered in the dispersion modeling analysis for off-site 
locations and census block centroids should generally yield 
overestimates of ambient HAP concentrations.
c. Uncertainties in Inhalation Exposure
    The effects of human mobility on exposures were not included in the 
assessment. Specifically, short-term mobility and long-term mobility 
between census blocks in the modeling domain were not considered.\29\ 
The assumption of not considering short- or long-term population 
mobility does not bias the estimate of the theoretical MIR, nor does it 
affect the estimate of cancer incidence since the total population 
number remains the same. It 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 increasing the estimated number of people at specific risk 
levels.
---------------------------------------------------------------------------

    \29\ Short-term mobility is movement from one micro-environment 
to another over the course of hours or days. Long-term mobility is 
movement from one residence to another over the course of a 
lifetime.
---------------------------------------------------------------------------

    In addition, the assessment predicted the chronic exposures at the 
centroid of each populated census block as surrogates for the exposure 
concentrations for all people living in that block. Using the census 
block centroid to predict chronic exposures tends to over-predict 
exposures for people in the census block who live further from the 
facility, and under-predict exposures for people in the census block 
who live closer to the facility. Thus, using the census block centroid 
to predict chronic exposures may lead to a potential understatement or 
overstatement of the true maximum impact, but is an unbiased estimate 
of average risk and incidence.
    The assessments evaluate the cancer inhalation risks associated 
with continuous pollutant exposures over a 70-year period, which is the 
assumed lifetime of an individual. In reality, 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 risks posed by a given 
source category. Depending on the characteristics of the industry, 
these factors will, in most cases, result in an overestimate both in 
individual risk levels and in the total estimated number of cancer 
cases. However, in rare cases, where a facility maintains or increases 
its emission levels beyond 70 years, residents live beyond 70 years at 
the same location, and the residents spend most of their days at that 
location, then the risks could potentially be underestimated. Annual 
cancer incidence estimates from exposures to emissions from these 
sources would not be affected by uncertainty in the length of time 
emissions sources operate.
    The exposure estimates used in these analyses assume chronic 
exposures to ambient levels of pollutants. Because most people spend 
the majority of their time indoors, actual exposures may not be as 
high, depending on the characteristics of the pollutants modeled. For 
many of the HAP, indoor levels are roughly equivalent to ambient 
levels, but for very reactive pollutants or larger particles, these 
levels are typically lower. This factor has the potential to result in 
an overstatement of 25 to 30 percent of exposures.\30\
---------------------------------------------------------------------------

    \30\ U.S. EPA. National-Scale Air Toxics Assessment for 1996. 
(EPA 453/R-01-003; January 2001; page 85.)
---------------------------------------------------------------------------

    In addition to the uncertainties highlighted above, there are 
several factors specific to the acute exposure assessment that should 
be highlighted. The accuracy of an acute inhalation exposure assessment 
depends on the simultaneous occurrence of independent factors that may 
vary greatly, such as hourly emissions rates, meteorology, and human 
activity patterns. In this assessment, we assume that individuals 
remain for 1 hour at the point of maximum ambient concentration as 
determined by the co-occurrence of peak emissions and worst-case 
meteorological conditions. These assumptions would tend to overestimate 
actual exposures since it is unlikely that a person would be located at 
the point of maximum exposure during the time of worst-case impact.
d. Uncertainties in Dose-Response Relationships
    There are uncertainties inherent in the development of the dose-
response values used in our risk assessments for cancer effects from 
chronic exposures and noncancer effects from both chronic and acute 
exposures. Some uncertainties may be considered quantitatively, and 
others generally are expressed in qualitative terms. We note as a 
preface to this discussion a point on dose-response uncertainty that is 
brought out in the EPA 2005 Cancer Guidelines; namely, that ``the 
primary goal of the EPA actions is protection of human health; 
accordingly, as an agency policy, risk assessment procedures, including 
default options that are used in the absence of scientific data to the 
contrary, should be health protective.'' (EPA 2005 Cancer Guidelines, 
pages 1-7). This is the approach followed here as summarized in the 
next several paragraphs. A complete detailed discussion of 
uncertainties and

[[Page 72785]]

variability in dose-response relationships is given in the residual 
risk documentation, which is available in the docket for this action.
    Cancer URE values used in our risk assessments are those that have 
been developed to generally provide an upper bound estimate of risk. 
That is, they represent a ``plausible upper limit to the true value of 
a quantity'' (although this is usually not a true statistical 
confidence limit).\31\ In some circumstances, the true risk could be as 
low as zero; however, in other circumstances, the risk could also be 
greater.\32\ When developing an upper bound estimate of risk and to 
provide risk values that do not underestimate risk, health-protective 
default approaches are generally used. To err on the side of ensuring 
adequate health-protection, the EPA typically uses the upper bound 
estimates rather than lower bound or central tendency estimates in our 
risk assessments, an approach that may have limitations for other uses 
(e.g., priority-setting or expected benefits analysis).
---------------------------------------------------------------------------

    \31\ IRIS glossary (http://www.epa.gov/NCEA/iris/help_gloss.htm).
    \32\ An exception to this is the URE for benzene, which is 
considered to cover a range of values, each end of which is 
considered to be equally plausible and which is based on maximum 
likelihood estimates.
---------------------------------------------------------------------------

    Chronic noncancer reference (RfC and RfD) values represent chronic 
exposure levels that are intended to be health-protective levels. 
Specifically, these values provide an estimate (with uncertainty 
spanning perhaps an order of magnitude) of daily oral exposure (RfD) or 
of a continuous inhalation exposure (RfC) to the human population 
(including sensitive subgroups) that is likely to be without an 
appreciable risk of deleterious effects during a lifetime. To derive 
values that are intended to be ``without appreciable risk,'' the 
methodology relies upon an UF approach (U.S. EPA, 1993, 1994) which 
includes consideration of both uncertainty and variability. When there 
are gaps in the available information, UF are applied to derive 
reference values that are intended to protect against appreciable risk 
of deleterious effects. The UF are commonly default values,\33\ e.g., 
factors of 10 or 3, used in the absence of compound-specific data; 
where data are available, UF may also be developed using compound-
specific information. When data are limited, more assumptions are 
needed and more UF are used. Thus, there may be a greater tendency to 
overestimate risk in the sense that further study might support 
development of reference values that are higher (i.e., less potent) 
because fewer default assumptions are needed. However, for some 
pollutants, it is possible that risks may be underestimated. While 
collectively termed ``uncertainty factor,'' these factors account for a 
number of different quantitative considerations when using observed 
animal (usually rodent) or human toxicity data in the development of 
the RfC. The UF are intended to account for: (1) Variation in 
susceptibility among the members of the human population (i.e., inter-
individual variability); (2) uncertainty in extrapolating from 
experimental animal data to humans (i.e., interspecies differences); 
(3) uncertainty in extrapolating from data obtained in a study with 
less-than-lifetime exposure (i.e., extrapolating from sub-chronic to 
chronic exposure); (4) uncertainty in extrapolating the observed data 
to obtain an estimate of the exposure associated with no adverse 
effects; and (5) uncertainty when the database is incomplete or there 
are problems with the applicability of available studies. Many of the 
UF used to account for variability and uncertainty in the development 
of acute reference values are quite similar to those developed for 
chronic durations, but they more often use individual UF values that 
may be less than 10. UF are applied based on chemical-specific or 
health effect-specific information (e.g., simple irritation effects do 
not vary appreciably between human individuals, hence a value of 3 is 
typically used), or based on the purpose for the reference value (see 
the following paragraph). The UF applied in acute reference value 
derivation include: (1) Heterogeneity among humans; (2) uncertainty in 
extrapolating from animals to humans; (3) uncertainty in lowest 
observed adverse effect (exposure) level to no observed adverse effect 
(exposure) level adjustments; and (4) uncertainty in accounting for an 
incomplete database on toxic effects of potential concern. Additional 
adjustments are often applied to account for uncertainty in 
extrapolation from observations at one exposure duration (e.g., 4 
hours) to derive an acute reference value at another exposure duration 
(e.g., 1 hour).
---------------------------------------------------------------------------

    \33\ According to the NRC report, Science and Judgment in Risk 
Assessment (NRC, 1994) ``[Default] options are generic approaches, 
based on general scientific knowledge and policy judgment, that are 
applied to various elements of the risk assessment process when the 
correct scientific model is unknown or uncertain.'' The 1983 NRC 
report, Risk Assessment in the Federal Government: Managing the 
Process, defined default option as ``the option chosen on the basis 
of risk assessment policy that appears to be the best choice in the 
absence of data to the contrary'' (NRC, 1983a, p. 63). Therefore, 
default options are not rules that bind the agency; rather, the 
agency may depart from them in evaluating the risks posed by a 
specific substance when it believes this to be appropriate. In 
keeping with EPA's goal of protecting public health and the 
environment, default assumptions are used to ensure that risk to 
chemicals is not underestimate risk). See EPA, 2004, An Examination 
of EPA Rick Assessment Principles and Practices, EPA/100/B-001 
available at: http://www.epa.gov/osa/pdfs/ratf-final.pdf.
---------------------------------------------------------------------------

    Not all acute reference values are developed for the same purpose 
and care must be taken when interpreting the results of an acute 
assessment of human health effects relative to the reference value or 
values being exceeded. Where relevant to the estimated exposures, the 
lack of short-term dose-response values at different levels of severity 
should be factored into the risk characterization as potential 
uncertainties.
    Although every effort is made to identify peer-reviewed reference 
values for cancer and noncancer effects for all pollutants emitted by 
the sources included in this assessment, some HAP continue to have no 
reference values for cancer or chronic noncancer or acute effects. 
Since exposures to these pollutants cannot be included in a 
quantitative risk estimate, an understatement of risk for these 
pollutants at environmental exposure levels is possible. For a group of 
compounds that are either unspeciated, or do not have reference values 
for every individual compound (e.g., glycol ethers), we conservatively 
use the most protective reference value to estimate risk from 
individual compounds in the group of compounds.
    Additionally, chronic reference values for several of the compounds 
included in this assessment are currently under the EPA IRIS review and 
revised assessments may determine that these pollutants are more or 
less potent than the current value. We may re-evaluate residual risks 
for the final rulemaking if these reviews are completed prior to our 
taking final action for these source categories and if dose-response 
metric changes enough to indicate that the risk assessment supporting 
this notice may significantly understate human health risk.
    When we identify acute impacts which exceed their relevant 
benchmarks, we pursue refining our acute screening estimates. For the 
Mineral Wool Production source category, we used a refined emissions 
multiplier of 3 to estimate the peak hourly emission rates from the 
average rates. For a detailed description of how the refined emissions 
multiplier was developed for the Mineral Wool Production source 
category see the memo on the Acute Effects Factor for Mineral Wool 
Manufacturing

[[Page 72786]]

Operations, which is in the docket for this action. For the Wool 
Fiberglass Manufacturing source category, data were not available to 
develop a refined emissions multiplier; therefore, the default 
emissions multiplier of 10 was used.
e. Uncertainties in the Multi-Pathway and Environmental Effects 
Assessment
    We generally assume that when exposure levels are not anticipated 
to adversely affect human health, they also are not anticipated to 
adversely affect the environment. For each source category, we 
generally rely on the site-specific levels of PB-HAP emissions to 
determine whether a full assessment of the multi-pathway and 
environmental effects is necessary. As discussed above, we conclude 
that the potential for these types of impacts is low for these source 
categories.
f. Uncertainties in the Facility Wide Risk Assessment
    Given that the same general analytical approach and the same models 
were used to generate facility wide risk results as were used to 
generate the source category risk results, the same types of 
uncertainties discussed above for our source category risk assessments 
apply to the facility wide risk assessments. Because the source 
category processes are the only processes at each facility, there is no 
greater uncertainty for facility wide emissions.

B. How did we consider the risk results in making decisions for this 
proposal?

    Based on our risk assessment we are proposing that risks due to 
hexavalent chromium and formaldehyde are acceptable, with a maximum 
individual cancer risk for the source category at 40-in-one million. 
Emissions testing at the facility presenting this risk indicated that 
92 percent of the total chromium compounds were hexavalent chromium. In 
the second step of the process, the EPA sets the standard at a level 
that provides an ample margin of safety.
    We found from our risk assessment that risks due to hexavalent 
chromium were acceptable at 40-in-one million. In the second step of 
our risk assessment, we considered whether any cost-effective measures, 
technologies or practices are available to reduce risks further to an 
``ample margin of safety''. We found two methods whereby hexavalent 
chromium emissions can be reduced at wool fiberglass facilities and we 
are proposing in this action emission limits for hexavalent chromium 
from wool fiberglass facilities that will provide an ample margin of 
safety to protect the public health and prevent adverse environmental 
effects. We discuss these methods further in Sections V.A., VIII. D and 
VIII. E of this preamble.
    In past residual risk actions, the EPA has presented and considered 
a number of human health risk metrics associated with emissions from 
the category under review, including: the MIR; the numbers of persons 
in various risk ranges; cancer incidence; the maximum non-cancer HI; 
and the maximum acute non-cancer hazard (72 FR 25138, May 3, 2007; 71 
FR 42724, July 27, 2006). In our most recent proposals (75 FR 65068, 
October 21, 2010 and 75 FR 80220, December 21, 2010), the EPA also 
presented and considered additional measures of health information, 
such as estimates of the risks associated with the maximum level of 
emissions which might be allowed by the current MACT standards (see, 
e.g., 75 FR 65068, October 21, 2010 and 75 FR 80220, December 21, 
2010). The EPA also discussed and considered risk estimation 
uncertainties. The EPA is providing this same type of information in 
support of the proposed actions described in this Federal Register 
notice.
    The agency is considering all available health information to 
inform our determinations of risk acceptability and ample margin of 
safety under CAA section 112(f). The agency acknowledges that the 
Benzene NESHAP provides flexibility regarding what factors the EPA 
might consider in making determinations and how these factors might be 
weighed for each source category. Thus, the level of the MIR is only 
one factor to be weighed in determining acceptability of risks.
    The EPA wishes to point out that certain health information has not 
been considered to date in making residual risk determinations. In 
assessing risks to populations in the vicinity of the facilities in 
each category, we present risk estimates associated with HAP emissions 
from the source category alone (source category risk estimates) and the 
risks due to HAP emissions from the entire facility at which the 
covered source category is located (facility wide risk estimates). We 
have not attempted to characterize the risks associated with all HAP 
emissions impacting the populations living near the sources in these 
categories. That is, at this time, we do not attempt to quantify those 
HAP risks that may be associated with emissions from other facilities 
that are not included in the source categories in question, including 
mobile source emissions, natural source emissions, persistent 
environmental pollution, and atmospheric transformation in the vicinity 
of the sources in these categories.
    The agency understands the potential importance of considering an 
individual's total exposure to HAP in addition to considering exposure 
to HAP emissions from the source category and facility. This is 
particularly important when assessing non-cancer risks, where 
pollutant-specific exposure health reference levels (e.g., RfC) are 
based on the assumption that thresholds exist for adverse health 
effects. For example, the agency recognizes that, although exposures 
attributable to emissions from a source category or facility alone may 
not indicate the potential for increased risk of adverse non-cancer 
health effects in a population, the exposures resulting from emissions 
from the facility in combination with emissions from all of the other 
sources (e.g., other facilities) to which an individual is exposed may 
be sufficient to result in increased risk of adverse non-cancer health 
effects. In May 2010, the EPA SAB advised us ``* * * that RTR 
assessments will be most useful to decision makers and communities if 
results are presented in the broader context of aggregate and 
cumulative risks, including background concentrations and contributions 
from other sources in the area.'' \34\
---------------------------------------------------------------------------

    \34\ The EPA's response to this and all other key 
recommendations of the SAR's advisory on RTR risk assessment 
methodologies (which is available at: http://yosemite.epa.gov/sab/
sabproduct.nsf/4AB3966E263D943A8525771F00668381/$File/EPA-SB-10-007-
unsigned.pdf) are outlined in a memo to this rulemaking docket from 
David Guinnup entitled, EPA's Actions in Response to the Key 
Recommendations of the SAB Review of RTR Risk Assessment 
Methodologies.
---------------------------------------------------------------------------

    Although we are interested in placing source category and facility 
wide HAP risks in the context of total HAP risks from all sources 
combined in the vicinity of each source, we are concerned about the 
uncertainties of doing so. At this point, we believe that such 
estimates of total HAP risks will have significantly greater associated 
uncertainties than for the source category or facility wide estimates, 
and hence would compound the uncertainty in any such comparison. This 
is because we have not conducted a detailed technical review of HAP 
emissions data for source categories and facilities that have not 
previously undergone an RTR review or are not currently undergoing such 
review.

C. How did we perform the technology review?

    For our technology review, we identified and evaluated the 
developments in practices, processes and control technologies that have

[[Page 72787]]

occurred since the 1999 MACT rules were promulgated. In cases where we 
identified such developments, we analyzed the technical feasibility of 
and the estimated impacts (costs, emissions reductions, risk 
reductions, etc.) of applying these developments. We then decided, 
based on impacts and feasibility, whether it was necessary to propose 
amendments to the regulation to require any of the identified 
developments.
    Based on our analyses of the data, information collected under the 
voluntary industry survey, our general understanding of both of the 
industries and other available information on potential controls for 
these industries, we identified potential developments in practices, 
processes, and control technologies.
    For the purpose of this exercise, we considered any of the 
following to be a ``development'':
     Any add-on control technology or other equipment that was 
not identified and considered during development of the 1999 MACT 
rules.
     Any improvements in add-on control technology or other 
equipment (that were identified and considered during development of 
the 1999 MACT rules) that could result in significant additional 
emissions reduction.
     Any work practice or operational procedure that was not 
identified or considered during development of the 1999 MACT rules.
     Any process change or pollution prevention alternative 
that could be broadly applied to the industry and that was not 
identified or considered during development of the 1999 MACT rules.
     Any development in equipment or technology that could 
result in increased HAP emissions.
    In addition to reviewing the practices, processes, and technologies 
that were not considered at the time we developed the 1999 MACT rules, 
we reviewed a variety of data sources for the mineral wool and wool 
fiberglass industries. Among the data sources we reviewed were the 
NESHAP for various industries that were promulgated after the 1999 MACT 
rules. We reviewed the regulatory requirements and/or technical 
analyses associated with these regulatory actions to identify any 
practices, processes and control technologies considered in these 
efforts that could possibly be applied to emissions sources in the 
Mineral Wool Production and Wool Fiberglass source categories, as well 
as the costs, non-air impacts, and energy implications associated with 
the use of these technologies. We reviewed scientific and technical 
literature regarding refractory products including high chrome 
refractories and consulted experts in the refractory manufacturing 
field.
    Control technologies, classified as RACT, BACT, or LAER apply to 
stationary sources depending on whether the sources are existing or 
new, and on the size, age and location of the facility. We consulted 
the EPA's RBLC to identify potential technology advances. BACT and LAER 
(and sometimes RACT) are determined on a case-by-case basis, usually by 
State or local permitting agencies. The EPA established the RBLC to 
provide a central database of air pollution technology information 
(including technologies required in source-specific permits) to promote 
the sharing of information among permitting agencies and to aid in 
identifying future possible control technology options that might apply 
broadly to numerous sources within a category or apply only on a 
source-by-source basis. The RBLC contains over 5,000 air pollution 
control permit determinations that can help identify appropriate 
technologies to mitigate many air pollutant emissions streams. We 
searched this database to determine whether it contained any practices, 
processes, or control technologies for the types of processes covered 
by the Mineral Wool Production and Wool Fiberglass Manufacturing MACT 
rules.
    Additionally, we requested information from facilities regarding 
developments in practices, processes, or control technology. Finally, 
we reviewed other information sources, such as State and local 
permitting agency databases and industry-supported databases.

D. What other issues are we addressing in this proposal?

    In addition to the analyses described above, we also reviewed other 
aspects of the MACT standards for possible revision. Based on this 
review we have identified several aspects of the MACT standards that we 
believe need revision. This includes proposing revisions to the 
startup, shutdown, and malfunction provisions of the MACT rule in order 
to ensure that they are consistent with a recent court decision in 
Sierra Club v. EPA, 551 F. 3d 1019 (DC Cir. 2008).
    We are proposing HAP-specific emission limits for COS, phenol, and 
methanol in place of surrogacy in the MACT standards. The proposed rule 
also would regulate the collection process as a source of HAP emissions 
of phenol, methanol and formaldehyde that were not included in the 1999 
Mineral Wool MACT standard.
    In addition, we are proposing other various minor changes with 
regards to editorial errors and other revisions to promote the use of 
plain language. The analyses and proposed decisions for these actions 
are presented in Section VI of this preamble.

E. What analyses were performed for the Mineral Wool Production source 
category under the Regulatory Flexibility Act?

    Section 609(b) of the RFA requires a Panel to be convened prior to 
publication of the IRFA that an agency may be required to prepare under 
the RFA. The RFA directs the Panel to report on the comments of small 
entity representatives and make findings on the following elements:
     A description and estimate of the number of small entities 
to which the proposed rule will apply;
     A description of projected reporting, recordkeeping and 
other compliance requirements of the proposed rule, including an 
estimate of the classes of small entities that will be subject to the 
requirements and the type of professional skills necessary for 
preparation of the report or record;
     An identification, to the extent practicable, of all 
relevant federal rules which may duplicate, overlap, or conflict with 
the proposed rule; and
     Descriptions of any significant alternatives to the 
proposed rule which accomplish the stated objectives of applicable 
statutes and which minimize any significant economic impact of the 
proposed rule on small entities. This analysis must discuss any 
significant alternatives such as:
     The establishment of differing compliance or reporting 
requirements or timetables that take into account the resources 
available to small entities;
     The clarification, consolidation, or simplification of 
compliance and reporting requirements under the rule for such small 
entities;
     The use of performance rather than design standards; and
     An exemption from coverage of the rule, or any part 
thereof, for such small entities.
    Once completed, the Panel Report presents the results of the 
analyses identified in the above list, and is provided to the agency 
issuing the proposed rule and is included in the rulemaking record. The 
agency is to consider the Panel's findings when completing the draft of 
the proposed rule. In light of the Panel Report, and where appropriate, 
the agency is also to consider whether changes are needed to the IRFA 
for the proposed rule or the

[[Page 72788]]

decision on whether an IRFA is required.
    The Panel's findings and discussion are based on the information 
available at the time the final Panel Report is published. The EPA will 
continue to conduct analyses relevant to the proposed rule, and 
additional information may be developed or obtained during the 
remainder of the rule development process.
    Any options identified by the Panel for reducing the rule's 
regulatory impact on small entities may require further analysis and/or 
data collection to ensure that the options are practicable, 
enforceable, environmentally sound and consistent with the CAA and its 
amendments. The Mineral Wool SBAR Panel convened on June 2, 2011, to 
address regulatory flexibility alternatives and opportunities for the 
mineral wool industry.

VI. Summary of Proposed Decisions and Actions

    Pursuant to CAA sections 112(d)(2), 112(d)(6) and 112(f), we are 
proposing to revise the 1999 MACT rules relative to mineral wool 
production and wool fiberglass manufacturing to include the standards 
and requirements summarized in this section. More details of the 
rationale for these proposed standards and requirements are provided in 
Sections VII and VIII of this preamble. In addition, as part of these 
rationale discussions, we solicit public comment and data relevant to 
several issues. The comments we receive during the public comment 
period will help inform the rule development process as we work toward 
promulgating a final action.

A. What are the proposed decisions and actions related to the Mineral 
Wool Production NESHAP?

    The following sections discuss the proposed decisions and actions 
regarding unregulated pollutants and emissions sources (i.e., the MACT 
floors), recordkeeping and notification, compliance and other proposed 
decisions and actions related to subcategorization of emissions sources 
and the findings of the SBAR Panel.
1. Addressing Unregulated Pollutants and Emissions Sources From Mineral 
Wool Production
    In the course of evaluating the 1999 MACT rule, we identified 
certain HAP for which we failed to establish emission standards in the 
original MACT (i.e., COS, HF, HCl, phenol, and methanol) and certain 
unregulated processes (i.e., collection). Some of these HAP (COS, 
phenol, and methanol) were not regulated under the 1999 MACT rule 
because they were represented by surrogates (i.e., CO and 
formaldehyde). The EPA did not regulate HF and HCl in the 1999 rule 
although these HAP are emitted from cupolas. The 1999 MACT rule also 
did not regulate any HAP emitted from collection processes that occur 
on a bonded line even though these processes emit the HAP phenol, 
formaldehyde, and methanol. According to National Lime v. EPA, 233 F.3d 
625, 634 (DC Cir. 2000), the EPA has a ``clear statutory obligation to 
set emissions standards for each listed HAP.'' As a part of the 
information collected in 2010 to support this proposal, we specifically 
evaluated COS, HF, and HCl from cupolas and formaldehyde, phenol and 
methanol from collection and curing operations.
    For the Mineral Wool Production source category, we are proposing 
MACT limits for: (1) COS, HF and HCl for existing, new and 
reconstructed cupolas; and (2) formaldehyde, phenol and methanol for 
existing, new and reconstructed combined collection and curing 
operations. The collection process emits HAP when a phenol-formaldehyde 
based binder is sprayed during collection. Such collection processes 
immediately precede curing ovens. Both processes emit HAP when they 
occur on bonded production lines, but of the two processes, only the 
curing oven was regulated under the 1999 MACT standard. This proposed 
rule regulates collection and curing as a combined process on bonded 
production lines under three subcategories (one subcategory for each 
combined process design). The proposed emissions limits were calculated 
using the 99 percent UPL method.
    We considered beyond-the-floor options for COS, HF, and HCl 
standards for all cupolas, and for formaldehyde, phenol and methanol 
for all combined collection and curing operation designs, as required 
by section 112(d)(2) of the Act. However, we decided not to propose any 
limits based on the beyond-the-floor analyses for COS, HF, HCl, 
formaldehyde, phenol, and methanol for these sources because of the 
costs, potential disadvantages of additional controls (including the 
cost of RTO and unintended SO2 emissions), non-air 
environmental impacts, and adverse energy implications associated with 
use of these additional controls. The beyond-the-floor analyses are 
presented in the technical documentation for this action (see MACT 
Floor Analysis for the Mineral Wool Production Manufacturing Source 
Category and the MACT Floor Analysis for the Wool Fiberglass 
Manufacturing Source Category), and are available in the docket for 
this action.
    In summary, we are proposing the following emissions limits for 
existing, new, and reconstructed cupolas in the Mineral Wool Production 
Source Category as presented in Table 2. We are not proposing changes 
to the PM emissions limits in the 1999 MACT rule for Mineral Wool 
Production, and for this reason they are not included in the proposed 
limits in Table 2 below.

Table 2--Mineral Wool Production Proposed Emissions Limits for Existing,
   New, and Reconstructed Cupolas, Pound of Pollutant per Ton of Melt
------------------------------------------------------------------------
                                             Emission limit (lb/ton of
                                                       melt)
                                         -------------------------------
                Pollutant                                     New and
                                             Existing      reconstructed
                                              cupolas         cupolas
------------------------------------------------------------------------
COS.....................................          3.3             0.017
HF......................................          0.014           0.014
HCl.....................................          0.0096          0.0096
------------------------------------------------------------------------

2. Subcategorization
    Under CAA section 112(d)(1), the EPA has the discretion to ``* * * 
distinguish among classes, types, and sizes of sources within a 
category or subcategory in establishing * * *'' standards. When 
separate subcategories are established, a MACT floor is determined 
separately for each subcategory. To determine whether

[[Page 72789]]

the mineral wool production facilities warrant subcategorization for 
the MACT floor analysis, the EPA reviewed unit and process designs, 
operating information, and air emissions data compiled in the industry 
survey data set and other information collected by the agency for 
development of the NESHAP for this source category. Based on this 
review, the EPA concluded that there are significant design and 
operational differences in the collection operations at each of the 
three facilities that operate a bonded line in this source category.
    For the unregulated process that emits HAP (i.e., collection and 
curing for facilities that operate a bonded line), we are proposing to 
subcategorize combined collection operations and curing ovens designs 
into three subcategories based on what the industry is currently using: 
Vertical, horizontal and drum. When separate subcategories are 
established, a MACT standard is determined separately for each 
subcategory. To determine whether the mineral wool production 
facilities warrant subcategorization for the MACT floor analysis, the 
EPA reviewed unit and process designs, operating information and air 
emissions data compiled in the industry survey data set and other 
information collected by the agency for development of the NESHAP for 
this source category. Based on this review, the EPA concluded that 
there are significant design and operational differences in the 
collection operations at each of the three facilities that operate a 
bonded line in this source category. The combined collection and curing 
designs consist of three design types: Vertical, horizontal and drum. 
For each existing, new, and reconstructed combined collection and 
curing operation, we are proposing the following emissions limits as 
presented in Table 3.

Table 3--Mineral Wool Production Proposed Emissions Limits for Existing,
 New, and Reconstructed Combined Collection and Curing Operations, Pound
                      of Pollutant per Ton of Melt
------------------------------------------------------------------------
                                                          Emission limit
              Design                      Pollutant         (lb/ton of
                                                               melt)
------------------------------------------------------------------------
Vertical..........................  Formaldehyde........         0.46
                                    Phenol..............         0.52
                                    Methanol............         0.63
Horizontal........................  Formaldehyde........         0.054
                                    Phenol..............         0.15
                                    Methanol............         0.022
Drum..............................  Formaldehyde........         0.067
                                    Phenol..............         0.0023
                                    Methanol............         0.00077
------------------------------------------------------------------------

3. Reporting and Recordkeeping Notifications
    We are proposing to revise certain reporting and recordkeeping 
requirements of 40 CFR part 63, subpart DDD. Specifically, we are 
proposing that facilities maintain records and prepare and submit 
performance test reports on the frequency described below in Compliance 
Dates and Approaches to comply with the proposed emissions limits for 
COS, HF, HCl, formaldehyde, phenol, methanol and the existing PM limit. 
Although the PM limits in the existing MACT do not change as a result 
of this proposed rule we are proposing the same reporting, 
recordkeeping requirements for PM as for the other pollutants addressed 
under this proposed rule. We are also proposing language that would 
require the use of electronic reporting for all test methods that are 
supported by the ERT. Methods supported by ERT may be found at http://www.epa.gov/ttn/chief/ert/index.html.
4. Compliance Dates and Approaches
    We are proposing that facilities that commenced construction or 
reconstruction on or before November 25, 2011 must demonstrate 
compliance with the requirements of this subpart no later than 3 years 
after the effective date of this rule. Affected sources that commenced 
construction or reconstruction after the effective date of this rule 
must demonstrate compliance with the requirements of this subpart no 
later than the effective date of the rule or upon start-up, whichever 
is later.
    We are proposing that compliance testing for PM, COS, formaldehyde, 
phenol and methanol be conducted using the same test methods as 
required by the 1999 MACT rule (i.e., Method 5 for PM and Method 318 
for the organic HAP). We are proposing that sources can use either Test 
Method 26A or Test Method 320 to determine compliance for HF and HCl.
    We are proposing both an initial performance test and repeat 
testing every 5 years or more often if the raw materials charged to the 
cupola change by more than 10 percent of that used for the initial 
performance test. Finally, we propose that continuous monitoring of 
appropriate operating parameters for control devices (e.g., RTO), 
cupolas, curing ovens and/or collection operations will be required as 
parametric monitoring. This is to ensure continuous compliance with the 
PM, COS, HF, HCl, formaldehyde, phenol and methanol emissions limits.
5. Other Decisions and Actions
    In addition to the proposed decisions and actions discussed above, 
we are also proposing changes to the use of surrogates in the existing 
rule and to subcategorize the combined collection operations and curing 
oven designs from those facilities operating bonded lines. We also 
discuss here the findings of the SBAR panel.
a. Surrogacy
    As described in Sections III.B and VII.B of this preamble, the 
court, in the Brick MACT decision (Sierra Club v. EPA, 479 F.3d 875 (DC 
Cir. March 13, 2007))\3\, found that the EPA has a ``clear statutory 
obligation to set emission standards for each listed HAP,'' which does 
not allow it to ``avoid setting standards for HAP not controlled with 
technology.'' Because we did not conduct analyses that would support 
the use of CO as a surrogate for COS, or formaldehyde for methanol and 
phenol, we cannot demonstrate that we established emission limits for 
COS, methanol and phenol in the 1999 MACT standard. Therefore, the 
agency is proposing to add emission limits for both phenol and 
methanol. Similarly, the agency is proposing to discontinue the use of 
CO as a surrogate for COS, and to set emission limits for COS. The 
proposed emissions limits for formaldehyde, phenol, methanol and COS 
are presented in Tables 2 and 3, above. We are soliciting comment on 
our decisions to discontinue use of

[[Page 72790]]

formaldehyde and CO as surrogates; any person wishing to establish or 
reestablish surrogacy relationships of one pollutant for others should 
provide emissions testing to support their conclusions.
b. Small Business Advocacy Review Panel
    For purposes of assessing the impacts of the proposed rule on small 
entities, the RFA defines small entities as including ``small 
businesses,'' ``small governments,'' and ``small organizations'' (5 
U.S.C. 601). The regulatory revisions being considered by the EPA for 
this rulemaking are expected to affect a variety of small businesses, 
but would not affect any small governments or small organizations. The 
RFA references the definition of ``small business'' found in the Small 
Business Act, which authorizes the SBA to further define ``small 
business'' by regulation. The SBA definitions of small business by size 
standards using the NAICS can be found at 13 CFR 121.201. For the 
Mineral Wool Production source category (NAICS code 327993), the SBA 
size standard for a small business is 500 employees. Based on this size 
designation, there are currently 5 small businesses operating with a 
total number of 540 employees.
    Under section 609(b) of the RFA, the Panel is to report its 
findings related to these four items:
     A description of and, where feasible, an estimate of the 
number of small entities to which the proposed rule will apply;
     A description of the projected reporting, recordkeeping 
and other compliance requirements of the proposed rule, including an 
estimate of the classes of small entities which will be subject to the 
requirement and the type of professional skills necessary for 
preparation of the report or record;
     Identification, to the extent practicable, of all relevant 
federal rules which may duplicate, overlap or conflict with the 
proposed rule; and
     A description of any significant alternatives to the 
planned proposed rule which would minimize any significant economic 
impact of the proposed rule on small entities consistent with the 
stated objectives of the authorizing statute.
    The Panel's most significant findings and discussion with respect 
to each of these items are summarized below. To read the full 
discussion of the Panel findings and recommendations, see Section 9 of 
the Panel Report.
1. Number and Types of Entities Affected
    Six companies exist in this industry; five of the six companies are 
small businesses. All small businesses in the mineral wool production 
industry operate under NAICS code 327993.
2. Recordkeeping, Reporting and Other Compliance Requirements
    The proposed rule under consideration potentially impacts small 
businesses by requiring new emission limits on processes that were not 
regulated under the MACT standard promulgated in 1999, by requiring 
emission limits for pollutants that were not regulated under the MACT, 
or both processes and pollutants not regulated under the MACT. All 
companies are subject to Title V operating permits requirements, and as 
such will be required to add the newly regulated processes to their 
operating permits along with compliance demonstrations that the 
processes meet each pollutant emission limit in the rule. Compliance 
testing will be required to be conducted using EPA methods for each 
pollutant. Reporting and recordkeeping requirements are not expected to 
change from the MACT, with the exception of additional pollutants and 
processes included in such reports.
3. Related Federal Rules
    NAAQS: the most prevalent technology for reducing COS emissions 
will increase emissions of SO2. Under the current NAAQS, 
none of the small entities are in nonattainment areas, so installation 
of emissions control equipment should not subject them to additional 
permitting requirements under the SO2 NAAQS. However, the 
EPA cannot make such assurances about future NAAQS or future 
nonattainment zones, so there is a risk that future compliance with 
this rule could trigger additional emissions control requirements 
through the Title V/prevention of significant deterioration permit 
program.
    GHG: Most emissions control strategies identified by the EPA during 
the Panel would increase the energy intensity of mineral wool 
production. Although the Panel does not have specific information about 
the GHG emissions of individual facilities in this industry, these 
facilities could be subject to GHG permitting as that program is phased 
in under the Tailoring Rule.
4. Regulatory Flexibility Alternatives
    The Panel agrees that the EPA does not have discretion in a number 
of areas that SER commented upon. Specifically, the EPA does not have 
the discretion to set the MACT floor emission limits at levels 
suggested by the SER. The Panel recognizes that EPA has the authority 
to review the MACT standard for completeness, risk, and technology 
improvements, and that the agency is currently under court order to 
conduct the risk and technology review for the mineral wool source 
category and propose amendments to the standard by October 31, 2011, 
and promulgate the amendments by October 31, 2012. However, whenever 
opportunities for regulatory flexibility arise, and when that 
regulatory flexibility can work to lessen impacts to small businesses, 
the Panel recommends that the EPA propose amendments to the mineral 
wool MACT that offer such regulatory flexibility to the maximum extent 
possible. Specifically, these opportunities arise in the following 
situations:
     Selection of the averaging method in calculating the MACT 
floor for COS from cupolas and phenol, formaldehyde and methanol 
emissions from collection and curing processes; and
     Subcategorization of regulated processes, when 
appropriate.
    The Panel recommends that the EPA not require BTF emission limits 
for the mineral wool industry. Such limits are likely to have 
additional cost impacts to industry. In addition, the EPA did not 
identify BTF measures for consideration and has found that the results 
of the risk assessment show acceptable risks from this source category.
    The Panel recommends subcategorization of collection along the 
lines described in Section 3 of the Panel Report, specifically, 
subcategorization for vertical collection and curing, horizontal 
collection and curing, and drum collection and curing. Based on 
available information, the Panel believes that emission standards based 
on the average emission limits across both collection and curing 
processes at each of the three subcategories would minimize the burden 
on small entities while fully complying with the EPA's obligations 
under section 112. The Panel also recommends setting MACT limits for 
new sources equal to MACT limits for existing sources.
    The Panel recommends that the EPA allow the maximum amount of time 
within its discretion (3 years) and work with state permitting 
authorities to provide for the additional year permitted by the 
statute.
    The Panel recommends that the EPA provide a detailed discussion in 
the preamble to the proposed rule that outlines the manner in which 
small entities may demonstrate compliance

[[Page 72791]]

with the rule, when finalized, during start-up and shutdown. The Panel 
also recommends that the EPA propose allowing an affirmative defense 
against compliance actions for malfunction events, consistent with 
other section 112 rules recently promulgated. For more information on 
the SBAR Panel review process and findings, see Section IV.E of this 
preamble and the Final Report of the Small Business Advocacy Review 
Panel on the EPA's Planned Proposed Rule Risk and Technology Review 
(RTR) Amendments to the National Emission Standard for Hazardous Air 
Pollutants (NESHAP) for Mineral Wool Production October 2011 in the 
docket.
c. Technical Corrections to the Rule
    We are also proposing revisions to certain terms in the existing 
NESHAP. Specifically, we are proposing to replace the term 
``incinerator'' with ``regenerative thermal oxidizer'' to avoid 
confusion with rules promulgated under CAA section 129 and any new 
requirement that may be imposed on something called an ``incinerator''. 
We are also proposing to specify performance testing frequency for 
RTOs.

B. What are the proposed decisions and actions related to the Wool 
Fiberglass Manufacturing NESHAP?

    The following sections discuss the decisions proposed by this 
action with regard to the following topics: unregulated pollutants and 
emissions sources; the risk review; the technology review; our plans 
regarding area sources; recordkeeping, reporting and notification 
requirements; compliance requirements; and other proposed decisions and 
actions (i.e., changes in surrogacy and terminology cleanup).
1. Addressing Unregulated Pollutants and Emissions Sources
    In the course of evaluating the 1999 MACT rule, we identified 
certain HAP for which we failed to establish emission standards in the 
original MACT (i.e., HF, HCl, phenol and methanol). As stated earlier, 
the EPA has ``clear statutory obligation to set emissions standards for 
each listed HAP''. National Lime v. EPA, 233 F. 3d 625, 634 (DC Cir. 
2000). The EPA specifically evaluated HF and HCl, from glass-melting 
furnaces and formaldehyde, phenol and methanol from RS manufacturing 
lines and FA manufacturing lines.
a. Surrogacy
    As described in Sections III. B and VII.B of this preamble, the 
Court, in the Brick MACT decision, also found that the EPA erred when 
we did not establish emission limits for each HAP emitted from 
industrial processes regulated by the MACT standard. We are proposing 
to replace CO as a surrogate for COS with COS emissions limits. We are 
also proposing to discontinue use of formaldehyde as a surrogate for 
phenol and methanol. We are, therefore, proposing to add emission 
limits for COS, phenol and methanol. The proposed emissions limits can 
be found in Tables 4-6, below.

  Table 4--Proposed Emissions Limits for Rotary Spin (RS) Manufacturing
                                  Lines
                    [Pound of pollutant/ton of melt]
------------------------------------------------------------------------
                                                              New and
                Pollutant                   Existing RS    reconstructed
                                               lines         RS lines
------------------------------------------------------------------------
Formaldehyde............................            0.17         0.020
Phenol..................................            0.19         0.0011
Methanol................................            0.48         0.00067
------------------------------------------------------------------------


      Table 5--Proposed Emissions Limits for Flame Attenuation (FA)
                           Manufacturing Lines
                    [Pound of pollutant/ton of melt]
------------------------------------------------------------------------
                                                              New and
                Pollutant                   Existing FA    reconstructed
                                               lines         FA lines
------------------------------------------------------------------------
Formaldehyde............................            5.6             3.3
Phenol..................................            1.4             0.46
Methanol................................            0.50            0.50
------------------------------------------------------------------------


      Table 6--Proposed Emissions Limits for Glass-Melting Furnaces
                    [Pound of pollutant/ton of melt]
------------------------------------------------------------------------
                                                              New and
                Pollutant                    Existing      reconstructed
                                             furnaces        furnaces
------------------------------------------------------------------------
HF......................................          0.002          0.00078
HCl.....................................          0.0015         0.00078
------------------------------------------------------------------------

b. Emission Limits for Unregulated HAPs
    For the Wool Fiberglass Manufacturing source category, we are 
proposing MACT limits for HF and HCl for glass-melting furnaces; 
formaldehyde, phenol and methanol from existing, new, and reconstructed 
RS manufacturing lines; and formaldehyde, phenol and methanol from 
existing, new, and reconstructed FA manufacturing lines. The proposed 
emissions limits can be found in Tables 4-6 above.
    Section 112(d)(3)(B) of the CAA requires that the MACT standards 
for existing sources be at least as stringent as the average emissions 
limitation achieved by the best performing 12 percent of sources (for 
which the Administrator has or could reasonably

[[Page 72792]]

obtain emissions information) in a category with more than 30 sources. 
The Wool Fiberglass Manufacturing source category consists of 29 
facilities with approximately 80 glass-melting furnaces. Since there 
are more than 30 furnaces, we based the MACT floor limit on the average 
emissions limitation achieved by the best performing 12 percent of 
furnaces.
    The EPA must exercise its judgment, based on an evaluation of the 
relevant factors and available data, to determine the level of 
emissions control that has been achieved by the best performing sources 
under variable conditions. It is recognized in the case law that the 
EPA may consider variability in estimating the degree of emissions 
reduction achieved by best-performing sources and in setting MACT 
floors. See Mossville Envt'l Action Now v. EPA, 370 F.3d 1232, 1241-42 
(DC Cir 2004) (holding that the EPA may consider emissions variability 
in estimating performance achieved by best-performing sources and may 
set the floor at a level that a best-performing source can expect to 
meet ``every day and under all operating conditions''). More details on 
how we calculate MACT floors and how we account for variability are 
described in the MACT Floor Analysis for the Wool Fiberglass 
Manufacturing Source Category which is available in the docket for this 
proposed action.
    We considered beyond-the-floor options for the HF and HCl standards 
for all of the glass-melting furnaces and the formaldehyde, phenol and 
methanol standards for all RS manufacturing lines and FA manufacturing 
lines, as required by section 112(d)(2) of the Act. We decided not to 
propose any limits based on the beyond-the-floor analyses for any of 
these pollutants because of the costs, non-air environmental impacts, 
and adverse energy implications associated with use of these additional 
controls. The beyond-the-floor analysis is presented in the technical 
documentation for this action (MACT Floor Analysis for the Mineral Wool 
Production Source Category and the MACT Floor Analysis for the Wool 
Fiberglass Manufacturing Source Category).
2. Proposed Decisions Based on the Risk Review
    Based on the results of our risk assessment and risk review (which 
are described in more detail in Section VIII of this preamble), we are 
proposing emission limits for chromium compounds under the authority of 
section 112(f)(2) of the CAA of 0.006 pounds of total chromium per 
thousand tons of glass pulled. As explained in Section VIII of this 
preamble, we are proposing these limits as an outcome of our ample 
margin of safety analysis.
3. Proposed Decisions Based on the Technology Review for the Wool 
Fiberglass Industry
    As explained in Sections VI.B and VIII.E of this preamble, we are 
proposing emissions limits for PM, under section 112(d)(6) (see Table 
12 of Section VIII in this preamble). Furthermore, as explained in 
Section VIII.F of this preamble, we are proposing emissions limits for 
chromium compounds under section 112(d)(6) of the CAA as part of our 
technology review (see those sections for details) of 0.006 pounds of 
total chromium per thousand tons of glass pulled, which is the same 
limit we are proposing under Section 112(f)(2) of the CAA.
    In our technology review for this industry, we discovered and 
evaluated two new technology developments that affect emissions from 
wool fiberglass manufacturing furnaces: furnace control technologies 
and high chrome refractories. These are discussed below.
    Wool fiberglass furnaces are now equipped with air pollution 
control devices that achieve emissions of about 0.014 pounds PM per ton 
of glass produced. This is about 50 times lower than required under the 
MACT rule (0.5 lb PM per ton glass produced). In light of the record 
and additional data we received on PM emissions, we are proposing 
revised PM limits under the technology review of the wool fiberglass 
source category (as described in Section VIII of this preamble).
    Glass-melting furnaces are constructed using refractories, which 
direct the heat of the furnace back into the melt. We are aware of a 
new technology that is used to significantly extend the life of the 
wool fiberglass furnace: refractories that are made of almost 100 
percent chromium compounds and that are used to construct entire 
furnaces or very large parts of furnaces. Based on emission testing of 
one furnace, it appears that the levels of chromium compounds that can 
be emitted when glass-melting furnaces are constructed from high chrome 
refractories can be significant. This facility operates two furnaces. 
The total chromium compound emissions at this facility are estimated as 
913 lb/yr assuming that both furnaces emit at a similar rate. This 
includes 840 pounds of hexavalent chromium. Industry information 
indicates that the furnaces emitting the highest levels of chromium 
compounds are constructed in whole or in part from these types of 
refractories. (Notes of April 14, 2011; Region 7 Certainteed 
Notes).12 13
    It is our understandng that because of the corrosive properties of 
the molten glass, fresh refractory is continuously exposed to the 
molten glass along the metal/glass contact line in the glass-melting 
furnace process. This increases the surface area of the refractory that 
is exposed to the molten glass. As a result, when the glass furnace is 
constructed using high chrome refractories, the emission levels of 
chromium compounds continuously increase over the life of the furnace 
(Please refer to notes of April 14, 2011, telephone discussion between 
Susan Fairchild and Certainteed). One industry spokesperson estimated 
that 20,000 lb/yr of refractory are worn away from the inside walls of 
one wool fiberglass furnace and ducted to the control device before 
venting to the atmosphere.\35\
---------------------------------------------------------------------------

    \35\ Meeting between U.S. EPA, would fiberglass industry 
representatives and NAIMA (trade association). August 31, 2011. At 
USEPA offices in Research Triangle Park, NC.
---------------------------------------------------------------------------

    On August 31, 2011, industry representatives met with the agency to 
provide data, in an attempt to improve our understanding of the levels 
of chromium content in refractory products used at wool fiberglass 
furnaces and their impacts on chromium compound emissions. In the 
meeting industry representatives stated the following:
     The use of chromium in refractories is important to wool 
fiberglass operations because it extends the useful life of the 
furnace;
     Chromium content of furnaces vary from 0 to 95 percent; 
there is no distinction between the types of refractories used at the 
highest chrome emitting furnace and the refractories used to construct 
other glass furnaces that emit low levels of hexavalent chromium.
     The type of furnace used at the high chromium emitting 
facility may may be responsible for increased hexavalent chromium 
emissions.
    However, the information from the meeting appears to contradict 
other information on the reason for certain furnaces to have elevated 
chromium emissions. As previously discussed, emission test results from 
the 2010 testing and previous statements made to the EPA from owners/
operators (Notes of April 14, 2011, Certainteed; Region 7 Certainteed 
notes) seem to inply that the high chromium emissions are due to the 
chromium content of the refractory. Because of this contradictory 
information we are requesting

[[Page 72793]]

additional emissions testing of wool fiberglass furnaces (discussed 
below). We are also soliciting comment on whether and how to 
subcategorize industry according to furnace type, or type of 
refractory. Commenters should also provide emissions test data to 
support their assertions regarding the correct manner in which to 
subcategorize the industry.
    As shown in Table 12 of Section VIII of this preamble, we are 
proposing chromium compound emissions limits of 0.00006 lb/ton of glass 
produced. These limits would apply to wool fiberglass furnaces at major 
sources. However, there are no differences in furnaces at major sources 
and those at area sources. We are concerned about the levels of 
hexavalent chromium that can be emitted by area sources where furnaces 
may be constructed or reconstructed using high chrome refractories. We 
are announcing today our plans to regulate wool fiberglass area sources 
in a future action. We have issued a section 114 information collection 
request to the wool fiberglass industry to collect comprehensive 
information specific to the chrome content of the refractories used to 
construct their glass-melting furnaces and obtain complete chromium 
emissions test data. This information will enable us determine the 
scope of the source category (in terms of the universe of wool 
fiberglass producers that are area sources and that emit hexavalent 
chromium) to be regulated in the future action.
    We are requesting information specific to wool fiberglass furnaces, 
including information on the chromium content of the refractories used 
in furnace construction, process rates and emissions testing. 
Nevertheless, we are soliciting comment from the public on our approach 
to limit emissions of chromium compounds as well as other alternatives 
to reducing emissions of chromium compounds, especially hexavalent 
chromium.
4. Reporting, Recordkeeping and Notification Requirements
    We are proposing to revise certain recordkeeping requirements of 40 
CFR part 63, subpart NNN. Specifically, we are proposing that 
facilities maintain records and prepare and submit performance test 
reports to comply with the proposed emissions limits for PM, chromium 
compounds, HF, HCl, formaldehyde, phenol and methanol. Because 
refractory products can contain chromium compounds that can then be 
emitted to the ambient air during wool fiberglass manufacturing, we are 
proposing that owners/operators of glass manufacturing furnaces 
maintain records of the refractory brick composition from which the 
furnaces are constructed, including any rebricking or additional layers 
of refractory that are added to the outside furnace walls. In addition, 
owners and operators are required to keep records of the occurrence and 
duration of each malfunction or operation of the air pollution control 
equipment and monitoring equipment. We are also proposing requirements 
for the use of electronic reporting for all test methods that are 
supported by the ERT. Methods supported by ERT may be found at http://www.epa.gov/ttn/chief/ert/index.html.
5. Compliance Dates and Approaches
    With regard to formaldehyde, HCl, HF, phenol and methanol, we are 
proposing that facilities that commenced construction or reconstruction 
on or before November 25, 2011 must demonstrate compliance with the 
requirements of this subpart no later than 3 years after the effective 
date of this rule. Affected sources that commenced construction or 
reconstruction after the proposal date of this rule must demonstrate 
compliance with the requirements of this subpart no later than the 
effective date of the rule or upon start-up, whichever is later. We are 
proposing an initial performance test within 90 days of promulgation of 
the final rule.
    With regard to total chromium compounds, we are proposing that the 
requirements under CAA section 112(f)(2), if finalized, must be 
implemented no later than 90 days after the effective date of this 
rule, but the EPA may extend that timeframe for circumstances under 
which we believe the additional time is necessary for installation of 
air pollution control equipment or other measures to reduce HAP 
emissions. We are, therefore, allowing affected sources up to one year 
from the effective date of this rule to demonstrate compliance with the 
chromium emission limits. Consistent with CAA section 112(f)(4)(B), we 
are proposing that a one-year compliance period is necessary so that 
affected facilities have adequate time to install additional controls 
and demonstrate compliance, including the time necessary to purchase, 
install and test control equipment. Because these limits reflect the 
reductions from glass making furnaces required under both sections 
112(d)(6) and 112(f)(2), we believe a one-year compliance timeframe is 
needed for the same reasons provided above. In addition, we are 
proposing that the PM emissions limit that would reflect reductions 
required for the glass making furnaces pursuant to CAA section 
112(d)(6) must be met no later than one year after the effective date 
of this rule. We believe this time is needed to either enable 
installation of replacement bags, or if a facility decides to add a new 
baghouse in series with an existing baghouse, seek bids, select a 
vendor, install and test the new equipment; prepare and submit the 
reports in this proposed rule, if finalized.
    Therefore, we are proposing that wool fiberglass facilities would 
be required to show compliance with both PM and the chromium limits 
within 1 year of promulgation of this standard. We are soliciting 
comments on this aspect of this proposed action.
    Additionally, we propose that compliance with the proposed chromium 
compounds emissions limits be demonstrated by annual performance tests 
for all glass-melting furnaces subject to this rule as described in 
Section VI.B.2 of this preamble. We are proposing additional annual 
performance testing no later than 12 calendar months following the 
initial or previous performance or compliance test to demonstrate 
compliance with the chromium compounds emissions limit for furnaces.
    We are proposing both an initial performance test and repeat 
testing every 5 years on the RS and FA lines and each time the binder 
formulation changes by more than 10 percent as compared to the binder 
formulation used in the initial performance test. We are seeking 
comment on whether the binder formulation variability of 10 percent as 
used here is appropriate.
    We are proposing that compliance testing for PM, formaldehyde, 
phenol and methanol be conducted using the same test methods as 
required by the 1999 MACT rule (i.e., Method 5 for PM and Method 318 
for formaldehyde, phenol and methanol). We are proposing Test Method 
26A be used to determine compliance for HF and HCl and Test Method 0061 
be used to ensure compliance with the chromium compounds emission 
limit.
    We propose that continuous monitoring of temperatures of control 
devices (e.g., fabric filters, wet and dry ESP, scrubbers) for glass-
melting furnaces, RS manufacturing lines, and FA manufacturing lines 
will be required as parametric monitoring to ensure continuous 
compliance with the PM, chromium compounds, HF, HCl, formaldehyde, 
phenol and methanol emissions limits.
    Because the recent test data for glass-melting furnaces show a 
significant

[[Page 72794]]

portion of the chromium compounds are hexavalent chromium, we are 
requiring Test Method 0061 be used to ensure compliance with the 
chromium compounds emission limit and as the most cost effective method 
to determine both total chromium and hexavalent chromium from wool 
fiberglass furnace stacks. Sources must report both total chromium and 
hexavalent chromium using this method or all chromium emissions are 
assumed to be hexavalent chromium.
6. Other Decisions and Actions
    In addition to the proposed decisions and actions discussed above, 
we are also proposing surrogacy changes and some general cleanup in 
terminology to the existing rule.
    a. Surrogacy
    As described in Sections III.B and VIII.B in this preamble, the 
Court found that the EPA has a ``clear statutory obligation to set 
emission standards for each listed HAP.'' Because we did not conduct 
analyses that would support the use of formaldehyde as a surrogate for 
methanol and phenol, we cannot currently demonstrate that we 
established emission limits for the HAP methanol and phenol in the 1999 
MACT standard. Therefore, we are proposing the emissions limits for 
phenol and methanol, which are presented in Tables 4-6, above.
    b. Technical corrections to the rule.
    We are also proposing revisions to certain terms in the existing 
NESHAP. Specifically, we are proposing to replace the term 
``incinerator'' with ``RTO'' and specify performance test frequency.

C. What are the proposed decisions and actions related to startup, 
shutdown and malfunction?

    The United States Court of Appeals for the District of Columbia 
Circuit vacated portions of two provisions in the EPA's CAA section 112 
regulations governing the emissions of HAP during periods of SSM. 
Sierra Club v. EPA, 551 F.3d 1019 (DC Cir. 2008), cert. denied, 130 S. 
Ct. 1735 (U.S. 2010). Specifically, the Court vacated the SSM exemption 
contained in 40 CFR 63.6(f)(1) and 40 CFR 63.6(h)(1), that are part of 
a regulation, commonly referred to as the ``General Provisions Rule,'' 
that the EPA promulgated under CAA section 112. When incorporated into 
CAA section 112(d) regulations for specific source categories, these 
two provisions exempt sources from the requirement to comply with the 
otherwise applicable CAA section 112(d) emissions standard during 
periods of SSM.
    We are proposing the elimination of the SSM exemption in this rule. 
Consistent with Sierra Club v. EPA, the EPA is proposing standards in 
this rule that apply at all times. We are also proposing several 
revisions to Table 1 to subparts DDD and NNN of part 63 (the General 
Provisions Applicability table). For example, we are proposing to 
eliminate the incorporation of the General Provisions' requirement that 
the source develop an SSM plan. We also are proposing to eliminate or 
revise certain recordkeeping and reporting that related to the SSM 
exemption. The EPA has attempted to ensure that we have not included in 
the proposed regulatory language any provisions that are inappropriate, 
unnecessary, or redundant in the absence of the SSM exemption. We are 
specifically seeking comment on whether there are any such provisions 
that we have inadvertently incorporated or overlooked.
    In proposing the standards in this rule, the EPA has taken into 
account startup and shutdown periods and, for the reasons explained 
below, is proposing emissions limits for those periods. Information on 
periods of startup and shutdown received from the industry survey 
indicate that emissions during these periods are less than emissions 
during production. Control devices such as baghouses for PM and metal 
HAP particulate control and RTO for COS control are started up before 
the process units, and are operational during the shutdown phase of a 
process. Therefore, no increase in emissions is expected during these 
periods. Because the processes are ducted to the control device before 
startup and after shutdown, and because emissions during startup and 
shutdown are not more than emissions during production, startup and 
shutdown emissions limits should be equivalent to the emissions limits 
for production. Production based emissions limits are expressed in this 
rule on a pound of pollutant per ton melt basis. However, during 
startup and shutdown, there is no melt being produced. Therefore, 
separate standards for periods of startup and shutdown were developed 
by translating the production-based emissions limits from a pound per 
ton basis to a pound of pollutant per hour basis and are being proposed 
in this rule. 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). The 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 emissions 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 emissions standards. 
Moreover, while the 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. Section 112 of the CAA 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.
    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 (DC Cir. 
1999) (the EPA typically has wide latitude in determining the extent of 
data-gathering necessary to solve a problem. The court generally defers 
to the 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 (DC 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

[[Page 72795]]

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. The EPA's approach to malfunctions is consistent with CAA 
section 112 and is a reasonable interpretation of the statute.
    In the event that a source fails to comply with the applicable CAA 
section 112(d) standards as a result of a malfunction event, the EPA 
would determine an appropriate response based on, among other things, 
the good faith efforts of the source to minimize emissions during 
malfunction periods, including preventative and corrective actions, as 
well as root cause analyses to ascertain and rectify excess emissions. 
The EPA would also consider whether the source's failure to comply with 
the CAA section 112(d) standard was, in fact, ``sudden, infrequent, not 
reasonably preventable'' and was not instead ``caused in part by poor 
maintenance or careless operation'' 40 CFR 63.2 (definition of 
malfunction).
    Finally, the EPA recognizes that even equipment that is properly 
designed and maintained can sometimes fail and that such failure can 
sometimes cause an exceedance of the relevant emissions standard (see, 
e.g., State Implementation Plans: Policy Regarding Excessive Emissions 
During Malfunctions, Startup, and Shutdown (Sept. 20, 1999); Policy on 
Excess Emissions During Startup, Shutdown, Maintenance and Malfunctions 
(Feb. 15, 1983)). The EPA is, therefore, proposing to add to the final 
rule an affirmative defense to civil penalties for exceedances of 
emissions limits that are caused by malfunctions. See 40 CFR 63.542 
(defining ``affirmative defense'' to mean, in the context of an 
enforcement proceeding, a response or defense put forward by a 
defendant, regarding which the defendant has the burden of proof, and 
the merits of which are independently and objectively evaluated in a 
judicial or administrative proceeding). We also are proposing other 
regulatory provisions to specify the elements that are necessary to 
establish this affirmative defense; the source must prove by a 
preponderance of the evidence that it has met all of the elements set 
forth in 40 CFR 63.552 (40 CFR 22.24). The criteria ensure that the 
affirmative defense is available only where the event that causes an 
exceedance of the emissions limit meets the narrow definition of 
malfunction in 40 CFR 63.2 (sudden, infrequent, not reasonable 
preventable and not caused by poor maintenance and or careless 
operation). For example, to successfully assert the affirmative 
defense, the source must prove by a preponderance of the evidence that 
excess emissions ``[w]ere caused by a sudden, infrequent, and 
unavoidable failure of air pollution control and monitoring equipment, 
process equipment, or a process to operate in a normal or usual manner 
* * *.'' The criteria also are designed to ensure that steps are taken 
to correct the malfunction, to minimize emissions in accordance with 40 
CFR 63.543(j) and to prevent future malfunctions. For example, the 
source must prove by a preponderance of the evidence that ``[r]epairs 
were made as expeditiously as possible when the applicable emissions 
limitations were being exceeded * * *'' and that ``[a]ll possible steps 
were taken to minimize the impact of the excess emissions on ambient 
air quality, the environment and human health * * *.'' In any judicial 
or administrative proceeding, the Administrator may challenge the 
assertion of the affirmative defense and, if the respondent has not met 
its burden of proving all of the requirements in the affirmative 
defense, appropriate penalties may be assessed in accordance with CAA 
section 113 (see also 40 CFR 22.27).
    The EPA included an affirmative defense in the proposed 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. The 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 (DC 
Cir. 2008). Thus, the 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 case law indicating that in many 
situations it is appropriate for the EPA to account for the practical 
realities of technology. For example, in Essex Chemical v. Ruckelshaus, 
486 F.2d 427, 433 (DC Cir. 1973), the DC 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 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 (DC Cir. 1973). Though 
intervening case law such as Sierra Club v. EPA and the CAA 1977 
amendments undermine the relevance of these cases today, they support 
the 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, the 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 
(DC 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.

D. What are the proposed decisions and actions related to electronic 
reporting?

    Records must be maintained in a form suitable and readily available 
for expeditious review, according to 63.10(b)(1). Electronic 
recordkeeping and reporting is available for many records, and is the 
form considered most suitable for expeditious review if available. 
Electronic recordkeeping and reporting is encouraged in this proposal 
and some records and reports are required to be kept in electronic 
format. Records required to be maintained electronically include the 
output of continuous monitors and the output of the BLDS. Additionally, 
standard operating procedures for the BLDS and fugitive emissions 
control are required to be submitted to the Administrator for approval 
in electronic format.

VII. Rationale for the Proposed Actions for the Mineral Wool Production 
Source Category

    As discussed in Section VI.A of this preamble, we evaluated 
emissions limits

[[Page 72796]]

for PM, COS, HF, HCl, formaldehyde, phenol and methanol at mineral wool 
production facilities. This section of the preamble provides the 
results of the RTR, our rationale for the proposed actions and 
decisions concerning changes to the 1999 MACT rule for the Mineral Wool 
Production source category.

A. What data were used for the NESHAP analyses?

    To perform the technology review and residual risk analysis for the 
Mineral Wool NESHAP, we created a comprehensive dataset based on 
existing and new test data provided by the 7 mineral wool facilities. 
As described in Section IV.C of this preamble, the voluntary industry 
survey requested available information regarding process equipment, 
control devices, point and fugitive emissions, practices used to 
control fugitive emissions, and other aspects of facility operations. 
In addition to the industry survey, each owner/operator was asked to 
submit reports for any recent emissions tests conducted at their 
facility and to conduct additional emissions tests in 2010 for certain 
HAP from specific processes. Pollutants tested for the mineral wool 
source category in 2010 included most HAP metals, CO, PM and certain 
organic HAP (formaldehyde, phenol, methanol and carbonyl sulfide).

B. What are the proposed decisions regarding surrogacy relationships?

    In the 1999 MACT rule, PM serves as the surrogate for metal HAP36 
at existing and new cupolas, CO serves as the surrogate for COS at new 
cupolas and formaldehyde serves as the surrogate for phenol and 
methanol from curing ovens. The 1999 MACT standard does not have 
emissions limits for COS, HCl or HF from existing cupolas; limits for 
phenol or methanol from curing; or emissions limits for any pollutants 
from collection operations. We are proposing HAP-specific emission 
limits for these pollutants under CAA section 112(d)(3)in this action. 
The agency is retaining use of PM as a surrogate for HAP metals. As 
discussed in Sections III.B and VII.B. of this preamble, the Court 
found that the EPA must set emission limits for each listed HAP (Sierra 
Club v. EPA, 479 F. 3d 875 (DC Cir. March 13, 2007)),\3\ and agreed 
with the EPA that nothing in the CAA suggests that it is prohibited 
from resetting the MACT floors in order to correct our own errors. They 
also agreed that the approach our petitioners labeled ``MACT-on-MACT'' 
would be more accurately described as ``MACT-on-Unsupportable-
Standards-Erroneously-Labeled-as-MACT'' \37\. With regard to the 
evaluation of potential MACT limits for HAP metals from this source 
category, consistent with the explanation presented in the proposal of 
the 1999 MACT rule (NESHAP for Mineral Wool Production, Proposed Rule, 
June 1, 1997, 64 FR 29490) for this source category describing the 
appropriateness of PM as a surrogate for HAP metals, we continue to 
consider PM as an appropriate surrogate for HAP metals in the proposed 
amendments to the NESHAP in this action.
---------------------------------------------------------------------------

    \36\ The HAP metals emitted from mineral wool cupolas include 
antimony, arsenic, beryllium, cadmium, chromium, cobalt, mercury, 
manganese, nickel, lead and selenium.
    \37\ Sierra Club v. EPA, 167 F. 3d 658 (DC Cir. March 2, 1999).
---------------------------------------------------------------------------

    The agency is proposing emissions limits for phenol and methanol 
because the concentration of formaldehyde in a specific binder 
formulation is independent of phenol and/or methanol. The mineral wool 
industry commented during the small business advocacy review that the 
binder ingredients and formulation can vary from one mineral wool 
company to the next, and that the test data from one company is not 
necessarily relevant for or representative of another company.
    In summary, under 112(d)(3) we are proposing emission limits for 
COS, HF and HCl from cupolas; and for formaldehyde, methanol and phenol 
from bonded lines.

C. What are the proposed decisions regarding certain unregulated 
emissions sources?

    In the course of evaluating the Mineral Wool Production source 
category, we identified certain HAP for which we failed to establish 
emission standards in the original MACT. See National Lime v. EPA, 233 
F. 3d 625, 634 (DC Cir. 2000) (the EPA has ``clear statutory obligation 
to set emissions standards for each listed HAP''). Specifically, we 
evaluated emissions standards for COS, HF and HCl for cupolas and 
formaldehyde, phenol and methanol for curing ovens and collection 
operations at mineral wool production facilities, that are not 
specifically regulated in the existing 1999 MACT standard. We are 
proposing emissions limits for these pollutants and processes pursuant 
to 112(d)(2) and 112(d)(3) as discussed in Section V.A of this 
preamble.

D. What are the proposed decisions regarding subcategorization?

    The EPA collected information from the mineral wool companies that 
operate bonded lines to better understand the different equipment 
designs and whether all collection processes are the same, or whether 
design and manufacturing process differences warranted consideration of 
subcategories for the collection process. This process led to the 
identification of three distinct process design subcategories: 
Vertical, horizontal and drum. Because collection processes only emit 
HAP if they occur on a bonded line, we are proposing to bundle 
collection operations and curing ovens together for each of three 
subcategories and propose new emissions limits for formaldehyde, 
phenol, and methanol at combined collection/curing on bonded lines. The 
following discussion involves the rationale for subcategorization of 
collection operations into three subcategories:
1. The Vertical Collection Design
    During the production of wool fiberglass on a bonded production 
line using a vertical collection design, the molten rock/slag mixture 
is poured from the cupola spout onto a group of stainless steel drums 
spinning in opposite directions. The spinning drums form fine fibers of 
the mineral mixture. High air volume directs the fibers off the 
fiberization spinners toward a fast-moving porous vertical conveyor 
belt. A strong vacuum is drawn on the opposite side of the belt causing 
the fibers to lie against the vertical belt as it moves upward. At the 
top of the conveyance, the belt travels around a curve, the vacuum is 
released, and the fibers are moved onto a second belt that conveys the 
layer of binder-sprayed mineral wool fibers into the curing oven. 
Because the conveyor belt is vertical, the air volume drawn through the 
belt and fiber layer must be very high and the resulting fiber layer 
that is collected on the belt is thin. In this design, `shot' (BB-sized 
black granules that are high in iron as a result of using slag from the 
iron and steel industry) falls out of the fiber layer. The vertical 
design is used to produce a specific type of mineral wool that is low 
in `shot' and may be used in the hydroponic gardening market as well as 
in a specialized market of insulation products in which shot is 
undesirable.
    Currently, only one facility operates this type of collection 
design. Formaldehyde, phenol and methanol MACT floors for existing, new 
and reconstructed sources in this

[[Page 72797]]

subcategory were based on emissions test runs for combined curing and 
collection operations from this facility.
2. The Horizontal Collection Design
    Horizontal collection is similar to vertical collection, but 
because the conveyor belt is horizontal it works with gravitational 
forces. The layer of mineral wool collected on a horizontal belt is 
thinner than that collected on a vertical belt, and the `shot' is not 
selectively removed. The air volume that is drawn through the fiber 
layer is much lower than in the vertical design, and therefore the air 
stream is conducive to thermal oxidation at the hottest part of the 
cupola exhaust stack or the existing thermal oxidizer on the curing 
oven.
    Currently, only one facility operates this type of collection 
design. Formaldehyde, phenol and methanol MACT floors for existing, new 
and reconstructed sources in this subcategory were based on emissions 
test runs for combined curing and collection operations from this 
facility.
3. The Drum Collection Design
    In the drum collection design, fibers are drawn using a very high 
volume air flow into the center of a rotating drum. The sides of the 
rotating drum have small holes that allow the air flow to exit, but 
which trap the fibers. The angle of the drum and the use of a vacuum 
and centrifugal force pull the fibers against the inside wall of the 
drum and out the end. The entire drum is enclosed and the air flow may 
be vented to the hottest part of the cupola exhaust stack or to the 
existing thermal oxidizer on the curing oven.
    Currently, only one facility operates this type of collection. 
Formaldehyde, phenol, and methanol MACT floors for existing, new, and 
reconstructed sources in this subcategory were based on emissions test 
runs for combined curing and collection operations from this facility.

E. What are the results from the risk assessments performed and the 
proposed decisions for the Mineral Wool Production source category?

    As described in Section V.A of this preamble, we conducted an 
inhalation risk assessment for all HAP emitted from the Mineral Wool 
Production source category. We also conducted multipathway screenings 
for cadmium, mercury, and lead. Details of the risk assessments and 
additional analyses can be found in the draft residual risk 
documentation referenced in Section V.A of this preamble, which is 
available in the docket for this action. The agency considered the 
available health information--the MIR; the numbers of persons in 
various risk ranges; cancer incidence; the maximum non-cancer HI; the 
maximum acute non-cancer hazard; the extent of non-cancer risks; the 
potential for adverse environmental effects; and the distribution of 
risks in the exposed population (54 FR 38044, September 14, 1989)--in 
developing the proposed CAA section 112(f)(2) standards for the Mineral 
Wool Production source category.
1. Inhalation Risk Assessment Results for the Mineral Wool Production 
Source Category
    Table 7 of this preamble provides an overall summary of the results 
of the inhalation risk assessment.

                                           Table 7--Mineral Wool Production Inhalation Risk Assessment Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
   Maximum individual cancer risk  (in 1 million) \1\                                       Maximum chronic non-cancer TOSHI
---------------------------------------------------------    Estimated        Estimated                    \2\
                                             Based on      population at    annual cancer  ----------------------------------   Maximum screening acute
                                            allowable      increased risk     incidence         Based on         Based on          non-cancer HQ \3\
    Based on actual emissions level         emissions     of cancer >=  1-    (cases per         actual         allowable
                                              level         in-1 million        year)       emissions level  emissions level
--------------------------------------------------------------------------------------------------------------------------------------------------------
4......................................              10            1,650           0.0004             0.04              0.1   8 (REL) 0.4 (AEGL-1, ERGP-
                                                                                                                               1).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Estimated maximum individual excess lifetime cancer risk due to HAP emissions from the source category.
\2\ Maximum TOSHI. The highest TOSHI for the Mineral Wool Production source category is for the respiratory system.
\3\ The maximum HQ acute value of 8 is driven by emissions of formaldehyde. It is also based on a refined emissions multiplier of 3 which was used to
  estimate the peak hourly emission rates from the average rates. See section V.A. of this preamble for explanation of acute dose-response values.

    The results of the chronic inhalation cancer risk assessment 
indicate that, based on estimates of current actual emissions, the MIR 
could be up to 4-in-1 million, with formaldehyde primarily driving 
these risks. The total estimated cancer incidence from this source 
category based on actual emission levels is 0.0004 excess cancer cases 
per year or one case in every 2,500 years, with emissions of 
formaldehyde and arsenic compounds contributing 64 percent and 33 
percent, respectively, to this cancer incidence.\38\ In addition, we 
note that no persons are estimated to have cancer risks greater than 
10-in-1 million, and approximately 1,650 people are estimated to have 
risks greater than 1-in-1 million as a result of emissions from 1 
facility. When considering the risks associated with MACT-allowable 
emissions, the MIR could be up to 10-in-1 million. The maximum modeled 
chronic non-cancer TOSHI value for the Mineral Wool Production source 
category could be up to 0.04 with emissions of formaldehyde dominating 
those impacts, indicating no significant potential for chronic non-
cancer impacts.
---------------------------------------------------------------------------

    \38\ We note that the MIR for this source category would not 
change if the CIIT URE for formaldehyde had been used in the 
assessment, although the total cancer incidence would decrease by 52 
percent. The MIR for the source category would remain at 40 due to 
Cr (VI). There is an ongoing IRIS reassessment for formaldehyde, and 
future RTR risk assessments will use the cancer potency for 
formaldehyde that results from that reassessment. As a result, the 
current results may not match those of future assessments.
---------------------------------------------------------------------------

    Our screening analysis for worst-case acute impacts indicates the 
potential for only one pollutant, formaldehyde, to exceed an HQ value 
of 1 at only one facility in this source category, with a potential 
maximum HQ up to 8. A refined emissions multiplier of 3 was used to 
estimate the peak hourly emission rates from the average rates. Refer 
to Appendix 7 of the draft residual risk document in the docket for a 
detailed description of how the refined emissions multiplier was 
developed for the Mineral Wool Production source category. The worst-
case acute impact estimate occurs at a facility that is located in a 
rural area with a small population. Since the acute modeling

[[Page 72798]]

scenario is worst-case because of its confluence of peak emission rates 
and worst-case dispersion conditions, and since the HQ estimates for 
formaldehyde based on the AEGL-1 and ERPG-1 values for this facility 
are well below 1, we are proposing to find that acute noncancer health 
impacts of concern are unlikely.
    With respect to the potential for adverse environmental effects 
from non PB-HAP, we note that that there is a lack of information about 
specific adverse environmental effects occurring at given 
concentrations of the HAP emitted by this source category. However, 
given that all chronic non-cancer HQ values considering actual 
emissions are less than 1 using human health reference values, we 
believe that it is unlikely that adverse environmental effects would 
occur at the actual HAP concentrations estimated in our human health 
risk assessment.
2. Multipathway Risk Assessments and Results
    There were no exceedances of screening emissions rates for the PB 
HAP emitted by the facilities in the Mineral Wool Production source 
category, thus we have no concerns about potential multi-pathway risks 
from this source category.
3. Facility Wide Risk Assessment Results
    For all facilities in this source category, there are no other 
significant HAP emissions sources present beyond those included in the 
source category. All significant HAP sources have been included in the 
source category risk analysis. Therefore, we conclude that the facility 
wide risks are essentially the same as the source category risks.

F. What are our proposed decisions for the Mineral Wool Production 
source category based on risk acceptability and ample margin of safety?

1. Risk Acceptability
    As noted in Section V.A of this preamble, we weigh all health risk 
factors in our risk acceptability determination, including the MIR; the 
numbers of persons in various risk ranges; cancer incidence; the 
maximum noncancer HI; the maximum acute noncancer hazard; the extent of 
noncancer risks; the potential for adverse environmental effects; and 
distribution of risks in the exposed population; and risk estimation 
uncertainty (54 FR 38044, September 14, 1989) in developing the 
proposed CAA section 112(f)(2) standards for this source category.
    Based on the inhalation risk assessment, we estimate that the 
cancer risks to the individual most exposed could be up to 4-in-1 
million due to actual emissions and up to 10-in-1 million due to MACT-
allowable emissions, mainly due to formaldehyde stack emissions. We 
estimate that the incidence of cancer based on actual emissions is 
0.0004 excess cancer cases per year or one case every 2,500 years, and 
that about 1,650 people face a cancer risk greater than 1-in-1 million 
due to HAP emissions from this source category. Our assessments also 
indicated a low potential for HAP emissions from these sources to pose 
any significant adverse environmental effects or human health multi-
pathway risks or chronic noncancer human health risks due to 
inhalation. While our acute risk screening ruled out the possibility of 
acute impacts of concern for all pollutants except for formaldehyde at 
one facility, we ultimately concluded that the potential for acute 
impacts of concern at this facility is low. The risk assessment for 
this source category was largely based on facility-specific stack test 
data and emissions estimates, indicating a high degree of confidence in 
the results. Considering all of the above information, we are proposing 
that the current risks due to actual HAP emissions from this source 
category are acceptable.
    While the estimated chronic risks associated with MACT-allowable 
emissions from this source category are slightly higher than risk 
estimates based on actual emission levels, they are still well below 
100 in one million and there are no other significant risks. Therefore, 
we propose the risks due to allowable emissions are also acceptable.
2. Ample Margin of Safety
    As explained earlier in Section V of this preamble, the agency 
again considers all of the health risks and other health information 
considered in the first step. Beyond that information, we evaluate the 
cost and feasibility of available control technologies and other 
measures (including the controls, measures and costs reviewed under the 
technology review) that could be applied in this source category to 
further reduce the risks due to emissions of HAP identified in our risk 
assessment.
    Based on our research and analyses as discussed in Section V.C of 
this preamble, we have not identified any feasible control options 
beyond what we are requiring in our proposed standards for emissions 
sources described above, and are therefore not proposing additional 
controls, under section 112(f)(2). Therefore, we are proposing that the 
MACT standards for the mineral wool production source category, as 
revised per above, provide an ample margin of safety to protect public 
health and prevent adverse environmental effects.
    Nevertheless, we are soliciting comments and information regarding 
additional control measures and work practices that may be available 
and their feasibility in further reducing stack emissions of COS, HF, 
HCl, formaldehyde, phenol, and methanol, or additional monitoring that 
may be warranted to ensure adequate control of these emissions.

G. What are the results from the technology review and proposed 
decisions?

    Based on our technology review, we believe that the reductions in 
HAP emissions since promulgation of the 1999 Mineral Wool Production 
MACT rule are directly related to improvements in two areas: (1) 
Improvements in fabric filter control technology (e.g., improved bag 
materials, replacement of older baghouses) and (2) addition of 
regenerative thermal oxidizers (RTOs) and oxygen injection to control 
emissions from cupolas. Additional reductions have been achieved due to 
the use of low-sulfur raw materials at one facility. The RTOs and lower 
sulfur raw materials are discussed above (in Section VII.C of this 
preamble) since these controls and measures are relevant to development 
of the MACT standards for COS and other organic HAPs under Section 
112(d)(2) of the CAA, and in the beyond the floor analyses (described 
in Section VII.C of this preamble) that we also do as part of the MACT 
standard evaluations under Section 112(d)(2) and 112(d)(3).
    In this section, as part of our technology review, we describe 
developments in development in fabric filter technologies and the 
relationship to PM emissions.
    Slight improvements in fabric filter control technology are 
reflected in the emissions test data collected under the industry 
survey. The emissions limit for PM under the 1999 MACT rule is a 
production-based limit of 0.1 pounds of PM per ton of melt for new and 
existing cupolas. Based on our analysis of survey responses and test 
data collected under the industry survey, this industry primarily uses 
fabric filters to control emissions of metal HAP, and sources affected 
by the current PM limit are achieving PM concentrations at control 
device outlets that are only slightly

[[Page 72799]]

below the current limit (see Technology Review for the Mineral Wool 
Production Manufacturing Source Category). Given fluctuations in 
control device performance and mineral wool production fluctuations, we 
do not believe that developments in practices, processes, and control 
technologies warrant revisions to the PM limit in the 1999 MACT rule to 
reflect HAP metal emissions levels achieved in practice.
    Moreover, the RBLC did not identify any practices, processes, or 
control technologies applicable to the emission sources in this source 
category that were not identified and evaluated during the original 
MACT development.
    In summary, we have not identified any additional relevant cost-
effective developments in technologies, practices or processes since 
promulgation of the MACT rule to further reduce HAP emissions. 
Therefore, we are not proposing any changes to the MACT standards in 
this action as a result of our technology review under Section 
112(d)(6) for Mineral Wool Production.
    Additional details regarding these analyses can be found in the 
following technical document for this action which is available in the 
docket: Technology Review for the Mineral Wool Production Manufacturing 
Source Category.

VIII. Rationale for the Proposed Actions for the Wool Fiberglass 
Manufacturing Source Category

    As discussed in Section VI.B of this preamble, we evaluated 
emissions limits for PM, chromium compounds, HF, HCl, formaldehyde, 
phenol, and methanol at wool fiberglass manufacturing facilities. This 
section of the preamble provides the results of the RTR, our rationale 
for the proposed actions for the Wool Fiberglass Manufacturing source 
category, and our proposed decisions concerning changes to the 1999 
MACT rule.

A. What data were used for the NESHAP analyses?

    To perform the technology review and residual risk analysis for the 
Wool Fiberglass Manufacturing NESHAP, we created a comprehensive 
dataset based on existing and new test data provided by 26 of the 29 
wool fiberglass facilities. As described in Section IV.C of this 
preamble, the voluntary industry survey requested available information 
regarding process equipment, control devices, point and fugitive 
emissions, practices used to control fugitive emissions, and other 
aspects of facility operations. In addition to the ICR survey, each 
facility was asked to submit reports for any recent emissions tests 
conducted and to conduct additional emissions tests in 2010 for certain 
HAP from specific processes. Pollutants tested for the wool fiberglass 
source category in 2010 included most HAP metals, PM, and certain 
organic HAP (HF, HCl, formaldehyde, phenol, and methanol).
    As discussed in Section IV.C above, in the emissions testing for 
the survey, industry requested to conduct emission testing on furnaces 
they believed were representative of the other furnaces in operation. 
The EPA and industry agreed that the bases for representativeness would 
include a variety of factors such as processing the same materials, 
producing the same products and being the same type of furnace. Furnace 
construction and refractory composition were not factors that were 
presented by industry as having an effect on HAP emissions, and those 
factors were not used as a basis of representativeness for the 
resulting data set. During analysis of the test data, the EPA 
discovered high emissions of chromium compounds, including hexavalent 
chromium, and that these emissions were mostly from certain furnaces 
constructed of high chrome refractories.
    The Wool Fiberglass Manufacturing source category consists of 29 
facilities with 80 furnaces, 54 RS manufacturing lines and less than 30 
FA manufacturing lines. Since there are more than 30 furnaces and RS 
lines, we based the MACT floor limits on the average emissions 
limitation achieved by the best performing 12 percent of sources. 
Therefore, the MACT floor for HF and HCl from glass-melting furnaces 
was based on the 10 best performing furnaces; the 7 best performing RS 
lines; and the 5 best performing FA lines.
    The stack test data were used to calculate the MACT floors using 
the 99 percent UPL for glass-melting furnaces, RS manufacturing lines, 
and FA manufacturing lines from wool fiberglass manufacturing plants. 
The UPL analysis is explained in more detail in MACT Floor Analysis for 
the Wool Fiberglass Manufacturing Source Category, which is available 
in the docket for this proposed action. The results from the MACT floor 
analysis are presented in Section VI.B of this preamble.

B. What are the proposed decisions regarding surrogacy relationships?

    A surrogate approach is used to allow for easier and less expensive 
measurement and monitoring requirements. In the 1999 MACT rule for this 
source category, PM serves as the surrogate for metal HAPs \39\ at 
existing and new glass-melting furnaces and formaldehyde serves as the 
surrogate for phenol and methanol from forming and curing at RS 
manufacturing lines and forming and curing at FA manufacturing lines. 
As described in Sections III.B and VIII.B in this preamble, the court 
found that the EPA erred when we did not set emission limits for each 
HAP emitted by industry processes in the MACT standards.\40\ Therefore, 
the agency is proposing HAP-specific emissions limits for phenol and 
methanol.
---------------------------------------------------------------------------

    \39\ The HAP metals emitted from wool fiberglass glass-melting 
furnaces include antimony, arsenic, beryllium, cadmium, chromium, 
cobalt, mercury, manganese, nickel, lead, and selenium.
    \40\ Sierra Club v. EPA, 479 F. 3d 875 (DC Cir. March 13, 2007).
---------------------------------------------------------------------------

C. What are the proposed decisions regarding certain unregulated 
emissions sources?

    As discussed earlier in Section VI.B of this preamble, we 
identified certain HAP for which we failed to establish emission 
standards in the original 1999 MACT. In the 1999 MACT rule, we used 
formaldehyde as a surrogate for phenol and methanol, and we did not 
establish HAP-specific emission limits for phenol, methanol, HF and 
HCl. For this action we evaluated emissions standards for HF, HCl, 
phenol, and methanol at wool fiberglass manufacturing facilities, 
described below, that are not specifically regulated in the existing 
1999 MACT standard. The EPA is therefore proposing to set emissions 
limits for these HAP emissions, under CAA section 112(d)(3) in this 
action.

D. What are the results from the risk assessments and analyses and the 
proposed decisions for the Wool Fiberglass Manufacturing source 
category?

    An inhalation risk assessment was completed for all HAP emitted for 
the Wool Fiberglass Manufacturing source category. Details of the risk 
assessments and additional analyses can be found in the residual risk 
documentation referenced in Section V.A of this preamble. The agency 
considered the available health information--the MIR; the numbers of 
persons in various risk ranges; cancer incidence; the maximum non-
cancer HI; the maximum acute non-cancer hazard; the extent of non-
cancer risks; the potential for adverse environmental effects; and 
distribution of risks in the exposed population (54 FR 38044, September 
14, 1989)--in developing the proposed CAA section 112(f)(2) standards 
for the Wool

[[Page 72800]]

Fiberglass Manufacturing source category.
1. Inhalation Risk Assessment Results for the Wool Fiberglass 
Manufacturing Source Category
    Table 8 of this preamble provides an overall summary of the results 
of the inhalation risk assessment.

                                        Table 8--Wool Fiberglass Manufacturing Inhalation Risk Assessment Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
    Maximum individual cancer risk (in 1 million) \1\                                       Maximum chronic non-cancer TOSHI
---------------------------------------------------------    Estimated        Estimated                    \2\
                                             Based on      population at    annual cancer  ----------------------------------   Maximum screening acute
                                            allowable      increased risk     incidence         Based on         Based on          non-cancer HQ \3\
    Based on actual emissions level         emissions     of cancer >=  1-    (cases per         actual         allowable
                                              level         in-1 million        year)       emissions level  emissions level
--------------------------------------------------------------------------------------------------------------------------------------------------------
40.....................................              60          849,000             0.05              0.2              0.5   30 (REL) 2 (AEGL-1, ERPG-
                                                                                                                               1).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Estimated maximum individual excess lifetime cancer risk due to HAP emissions from the source category. Hexavalent chromium is the primary driver
  for cancer risk.
\2\ Maximum TOSHI. The highest TOSHI for the Wool Fiberglass Manufacturing source category is for the respiratory system.
\3\ The maximum HQ acute value of 30 is driven by emissions of formaldehyde. See section V.A. of this preamble for explanation of acute dose-response
  values.

    The results of the chronic inhalation cancer risk assessment 
indicate that, based on estimates of current actual emissions, the 
maximum individual lifetime cancer risk (MIR) could be up to 40-in-1 
million. The major contributor to this cancer risk is hexavalent 
chromium that is emitted from the furnace refractory brick. The 
greatest amount of hexavalent chromium emitted from a single source is 
from a facility that currently uses a type of refractory brick that is 
made almost entirely of chromium compounds. In addition, we note that 
approximately 12,000 people are estimated to have cancer risks greater 
than 10-in-1 million as a result of formaldehyde and hexavalent 
chromium emissions at 2 facilities, and approximately 849,000 people 
are estimated to have risks greater than 1-in-1 million as a result of 
formaldehyde and hexavalent chromium emissions from 15 facilities. The 
maximum estimated chronic non-cancer TOSHI value for the Wool 
Fiberglass Manufacturing source category is 0.2 with emissions of 
formaldehyde dominating those impacts, indicating no significant 
potential for chronic non-cancer impacts.
    Based on the acute REL to assess possible acute non-cancer effects 
due to emissions of formaldehyde, our analysis indicates that the 
maximum acute HQ value could exceed a value of 1 at a total of 7 
facilities due to formaldehyde emissions,\41\ with one facility in this 
source category indicating the potential to create a maximum worst-case 
HQ value up to 30. This maximum worst-case acute impact corresponds to 
a maximum HQ of 2 based on the AEGL-1 and ERPG-1 levels for 
formaldehyde. Altogether, these results indicate that we cannot rule 
out the potential for formaldehyde emissions from this source category 
to cause acute impacts of mild concern, such as eye and nose 
irritation. Repeated exposures to these levels (i.e., at or above the 
AEGL-1 and ERPG-1) could cause further health concerns.
---------------------------------------------------------------------------

    \41\ Individual facility acute HQ values for all facilities can 
be found in Appendix 6 of the risk assessment document that is 
included in the docket for this proposed rulemaking.
---------------------------------------------------------------------------

    With respect to the potential for adverse environmental effects 
from non PB-HAP, we note that that there is a lack of information about 
specific adverse environmental effects occurring at given 
concentrations for the HAP emitted by this source category. However, 
given that all chronic non-cancer HQ values considering actual 
emissions are less than 1 using human health reference values, we 
believe that it is unlikely that adverse environmental effects would 
occur at the actual HAP concentrations estimated in our human health 
risk assessment.
2. Auxiliary Risk Characterization
    As indicated in Section VIII.D.1 above, the MIR for the Wool 
Fiberglass Manufacturing source category could be up to 40-in-1-million 
based on actual emissions. The major contributor to this cancer risk is 
hexavalent chromium. The greatest amount of risk is from one facility 
that uses a type of refractory brick that is described by the company 
as ``high chrome.''12 13 ((Notes of April 14, 2011, 
Certainteed); (Region 7 Certainteed Notes).
    Because the use of high chrome refractories extends the life of the 
furnace from a maximum of 10 years to at least 15 years, and the cost 
of furnace construction is increased by about 15 percent when it is 
reconstructed using high chrome refractories \12\ (Notes of April 14, 
2011, Certainteed) we believe that there is a financial incentive for 
other facilities to switch to this high chromium refractory at the time 
they rebuild their furnaces. For this reason, we performed an auxiliary 
risk characterization analysis to assess the potential maximum 
individual lifetime cancer risks in the event that the other 28 Wool 
Fiberglass facilities switch to the high chromium brick. For the 
auxiliary risk characterization analysis it was assumed that the 
hexavalent chromium emissions for each facility would be the same as 
that for the facility with annual emissions of 420 lbs of hexavalent 
chromium per furnace. Table 9 of this preamble provides a summary of 
the results of this auxiliary inhalation risk assessment.

[[Page 72801]]



               Table 9--Wool Fiberglass Manufacturing Auxiliary Inhalation Risk Assessment Results
----------------------------------------------------------------------------------------------------------------
Potential maximum individual cancer risk (in                                       Estimated
               1 million) \1\                    Estimated        Estimated      population at      Estimated
---------------------------------------------  population at    population at    increased risk   annual cancer
                                               increased risk   increased risk    of cancer >=      incidence
       Based on actual emissions level        of cancer >=  1- of cancer >= 10-     100-in-1        (cases per
                                                in-1 million     in-1 million       million           year)
----------------------------------------------------------------------------------------------------------------
900.........................................       7,300,000          460,000            8,100             0.46
----------------------------------------------------------------------------------------------------------------
\1\ Estimated maximum individual excess lifetime cancer risk due to HAP emissions from the source category.

    The results of the auxiliary analysis indicate that, under this 
scenario, the estimated emissions from 14 facilities could lead to 
maximum individual lifetime cancer risks greater than 100-in-1-million, 
with the highest emitting facility posing a potential maximum 
individual risk of 900-in-1-million. Under this scenario, 8,100 people 
would be exposed to risks greater than 100-in-1-million, 460,000 people 
would be exposed to risks of greater than 10-in-1-million, and over 7 
million people would be exposed to cancer risks of greater than 1-in-1-
million.
    In summary, the auxiliary risk analysis indicates that if other 
facilities switch to high chromium refractory, emissions of hexavalent 
chromium could potentially pose unacceptable risks to public health due 
to inhalation exposures resulting from stack emissions of hexavalent 
chromium.
3. Multipathway Risk Assessments and Results
    None of the facilities in the Wool Fiberglass Manufacturing source 
category reported emissions of PB HAP that were greater than the 
screening emission rates. Therefore, multi-pathway exposures and 
environmental risks were deemed negligible.
4. Facility Wide Risk Assessment Results
    For this source category, there are no other significant HAP 
emissions sources present beyond those included in the source category. 
All significant HAP sources have been included in the source category 
risk analysis. Therefore, we conclude that the facility wide risk is 
essentially the same as the source category risk and that no separate 
facility wide analysis is necessary.

E. What are our proposed decisions for the Wool Fiberglass 
Manufacturing source category based on risk acceptability and ample 
margin of safety?

1. Risk Acceptability
    As noted in Section VIII.D of this preamble, we weigh all health 
risk factors in our risk acceptability determination, including the 
MIR; the numbers of persons in various risk ranges; cancer incidence; 
the maximum noncancer HI; the maximum acute noncancer hazard; the 
extent of noncancer risks; the potential for adverse environmental 
effects; and distribution of risks in the exposed population; and risk 
estimation uncertainty (54 FR 38044, September 14, 1989) in developing 
the proposed CAA section 112(f)(2) standards for this source category.
    Based on the inhalation risk assessment, we estimate that the 
cancer risks to the individual most exposed could be up to as 40-in-1 
million due to actual emissions and up to as 60-in-1 million due to 
MACT-allowable emissions, mainly due to formaldehyde and chromium stack 
emissions. We estimate that the incidence of cancer based on actual 
emissions is 0.05 excess cancer cases per year or one case every 20 
years, and that about 850,000 people face a cancer risk greater than 1-
in-1 million due to the HAP emissions from this source category.
    Our assessments also indicate a low potential for HAP emissions 
from these sources to pose any significant adverse environmental 
effects, human health multi-pathway effects, or chronic noncancer human 
health risks. Our acute risk screening ruled out the possibility of 
acute impacts of concern for all pollutants but one, formaldehyde, at 
seven facilities, with a maximum worst-case HQ estimated to be 30 based 
on the REL and 2 based on the AEGL-1 (or ERPG-1, which is equivalent). 
While this means we cannot rule out the potential for acute concerns 
due to formaldehyde emissions from these facilities, we note that the 
use of formaldehyde is being phased out in this industry, and will be 
eliminated from all but 2 facilities in the source category. Since the 
cancer risks due to actual and allowable emissions (based on the 
current composition of refractory bricks used by this source category) 
are well within the acceptable range (i.e., less than 100-in-1 million) 
and since we have no additional significant concerns regarding other 
potential human health or environmental impacts, we are proposing that 
the current risk levels due to actual and MACT-allowable emissions are 
acceptable.
2. Ample Margin of Safety Analysis and Proposed Decisions
    As described above, we are proposing that the risks associated with 
the actual and MACT-allowable stack emissions from this source category 
are acceptable based on the current composition of refractory bricks 
used by this source category. However, as discussed in Section 
VIII.D(2) of this preamble, if other wool fiberglass facilities 
reconstructed their furnaces with high chromium refractory bricks, the 
maximum individual cancer risks would be higher and likely result in a 
finding of unacceptable risks.
    According to our 2-step process for assessing risks, after we 
evaluate whether risks are ``acceptable'' we evaluate whether cost 
effective measures are available to reduce risks further, to provide an 
``ample margin of safety.'' As stated in Section VIII.F of this 
preamble, both NaOH scrubbers and a furnace rebuild are considered cost 
effective when hexavalent chromium levels are high. NaOH scrubbers 
achieve at least 95 percent reduction in hexavalent chromium emissions 
at other industries. Transferring this technology to the wool 
fiberglass industry is reasonable and would reduce hexavalent chromium 
to levels that would achieve an ample margin of safety. Therefore, we 
are proposing emission limits of 0.06 lb of total chromium compounds 
per thousand tons (or 60 lb of total chromium compounds per million 
tons) of glass pulled in this action (as presented in Table 10) under 
Section 112(f)(2) of the CAA in this action. We believe this limit 
would achieve an ample margin of safety to protect public health and 
prevent adverse environmental effects.

[[Page 72802]]



 Table 10--Proposed Emissions Limits for Glass-Melting Furnaces Based on
                               Risk Review
------------------------------------------------------------------------
                                                           Pounds of
                                                         pollutant per
                      Pollutant                        thousand tons of
                                                             melt:
------------------------------------------------------------------------
Chromium compounds..................................               0.06
------------------------------------------------------------------------

    These emission limits apply to furnaces at major sources in the 
wool fiberglass manufacturing source category. However, there are no 
differences in furnaces at major sources and area sources. We are 
concerned about the levels of hexavalent chromium that can be emitted 
by area sources where furnaces may be constructed using high chrome 
refractories. Therefore we plan to collect additional information from 
industry to inform regulation of area sources in a future action.
    The emission limits we are proposing for chromium compounds under 
112(f)(2) are identical to the chromium compounds limits we are 
proposing under 112(d)(6), as described in Section VIII.F of this 
preamble.
    Our assessments also indicate a low potential for HAP emissions 
from these sources to pose any significant adverse environmental 
effects, human health multi-pathway effects, or chronic noncancer human 
health risks. Our acute risk screening ruled out the possibility of 
acute impacts of concern for all pollutants but one, formaldehyde, at 
seven facilities, with a maximum worst-case HQ estimated to be 30 based 
on the REL and 2 based on the AEGL-1 or ERPG-1, which is equivalent 
(formaldehyde). While this means we cannot rule out the potential for 
acute concerns due to formaldehyde emissions from these facilities, we 
note that the worst-case acute HQs are based on conservative 
assumptions (e.g., worst-case meteorology coinciding with peak short-
term one-hour emissions from each emission point, with a person located 
at the point of maximum concentration during that hour). Moreover, the 
use of formaldehyde is being phased out in this industry, and will be 
eliminated from all but 2 facilities in the source category. Since the 
cancer risks due to actual emissions are well within the acceptable 
range (i.e., less than 100 in 1 million) and since we have no 
additional significant concerns regarding other potential human health 
or environmental impacts, and since we have not identified any 
additional cost-effective controls to further reduce formaldehyde 
emissions, we are proposing that the MACT rule along with all the 
proposed amendments described above (including the emissions limits for 
chromium and formaldehyde) will provide an ample margin of safety to 
protect public health and prevent adverse environmental effects.
    We are soliciting comments and information regarding additional 
control measures, work practices that may be available, and their 
feasibility in further reducing emissions of formaldehyde, chromium 
compounds, HCl, and HF, or additional monitoring that may be warranted 
to ensure adequate control of stack emissions. We specifically request 
information on other criteria on which a chromium compounds emission 
limit should be based that would reduce risks from hexavalent chromium.
3. Analysis of the Resulting Risk After the Proposed Requirements Are 
in Place
    We conducted an assessment to estimate the risks based on a post-
control scenario reflecting all the proposed requirements for the 
emissions described above (including the proposed emissions limit for 
chromium compounds). Details are provided in the Draft Residual Risk 
Assessment for the Mineral Wool Production and Wool Fiberglass 
Manufacturing Source Categories, EPA's Office of Air Quality Planning 
and Standards Office of Air and Radiation, September 2011, which is 
available in the docket to this rule.
    Table 11 of this preamble provides an overall summary of the 
results of the post-control inhalation risk assessment. As compared to 
Table 8, the MIR decreased from 40 in 1 million to 20 in 1 million, 
primarily as a result of one facility replacing the high chrome 
refractory bricks at the facilities that currently exceed the proposed 
chromium standard. These estimates are based on the dataset compiled 
using the industry's emissions test data from their 2010 industry 
survey responses, which show three furnaces would have to reduce 
chromium emissions to meet the limit in the proposed rule.

                      Table 11--Post Control Inhalation Risk Estimates for Wool Fiberglass
                                          [Result of chromium control]
----------------------------------------------------------------------------------------------------------------
                                                                                Maximum chronic
                                                 Estimated        Estimated        non-cancer        Maximum
    Maximum individual cancer risk (in 1       population at    annual cancer    TOSHI based on  screening acute
million) based on actual emissions level \1\   increased risk     incidence          actual       non- cancer HQ
                                              of cancer >=  1     (cases per    emissions level        \3\
                                                in 1 million        year)             \2\
----------------------------------------------------------------------------------------------------------------
20..........................................         282,000             0.02              0.2               30
----------------------------------------------------------------------------------------------------------------

    In addition, we estimated that the formaldehyde emissions would be 
at or below the MACT standard for all facilities once this rule is 
fully implemented and we are not proposing that additional control 
options be implemented.
    In a letter dated June 8, 2011, the industry trade association 
(NAIMA) stated that ``NAIMA can provide documentation that all major 
sources have already converted or have announced plans to convert to 
non-phenol formaldehyde binders. Essentially non-formaldehyde binders 
are or will be used industry-wide.'' A copy of this letter has been 
placed in the docket for this action (see NAIMA's Response for the 
Fiberglass Industry to EPA's Formaldehyde and Collection Questions). 
Based on this information and the information provided by the industry 
in their 2010 survey, we estimate that 27 of the 29 wool fiberglass 
manufacturing facilities will have HAP emissions below the 10 and 25 
tpy thresholds and will not be subject to the major source MACT 
requirements. We further estimate that there may be two facilities 
manufacturing pipe insulation or heavy density insulation products that 
will be major sources of HAP emissions on the compliance date of these 
proposed amendments to subpart NNN. If NAIMA is correct in that 
formaldehyde will be phased out by the compliance date of these 
proposed amendments, we anticipate that the estimated inhalation risks 
due to formaldehyde would further decrease.

[[Page 72803]]

    In summary, we are proposing that the MACT standard, with the 
changes we are proposing in this action, will provide an ample margin 
of safety and prevent adverse environmental effects.

F. What are the results from the technology review and proposed 
decisions?

    Based on our technology review, we determined that there have been 
advances in emissions control measures since the Wool Fiberglass 
Manufacturing NESHAP was originally promulgated in 1999. Since 
promulgation, we estimate that industry-wide metal HAP emissions from 
process sources have been reduced by approximately 76 percent. Due to 
industry's efforts to replace phenol-formaldehyde binders, more than 95 
percent of formaldehyde, phenol, and methanol emissions have been 
reduced (or will be by 2012). As a result actual PM (metal HAP), 
formaldehyde, phenol, and methanol emissions from process sources at 
all wool fiberglass manufacturing facilities are significantly lower 
than are allowed under the 1999 MACT rule.
    We believe that the reductions in metal HAP emissions since 
promulgation of the 1999 MACT rule are mainly directly related to 
improvements in two areas: (1) Improvements in fabric filter control 
technology (e.g., improved bag materials, replacement of older 
baghouses) and (2) the use of electrostatic precipitators (ESPs). Our 
review also indicates that high chrome refractories are a new 
technology used in wool fiberglass furnaces that the available data 
indicate result in an increase in emissions of chromium compounds. The 
results of our analyses and our proposed decisions for these areas 
under CAA section 112(d)(6) are presented in the following sections. 
Based on these data, we believe that developments in practices, 
processes, and control technologies warrant revisions to the 1999 
NESHAP. Additional details regarding these analyses can be found in 
Technology Review for the Wool Fiberglass Manufacturing Source 
Category.
    The improvements in fabric filter control technology are reflected 
in the emissions test data collected under the industry survey. Two 
types of PM control are used in the wool fiberglass manufacturing 
industry: fabric filters (baghouses) and electrostatic precipitators. 
Electrostatic precipitators (ESP) may be configured as either wet ESPs 
or dry ESPs. The emissions limit for PM under the 1999 MACT rule is a 
production-based limit of 0.5 pounds of PM per ton of glass pulled 
applicable to all glass melting furnaces. Based on our analysis of 
survey responses and test data collected under the industry survey, 
this industry primarily uses fabric filters to control emissions of 
metal HAP, and the vast majority of sources affected by the current PM 
limit are achieving PM emissions at control device outlets that are far 
below the current limit. Id.
    Most, if not all, sources reported PM emissions (coming out of the 
stacks after the control devices) that are less than 10 percent of the 
current limit, with several sources achieving PM emissions that are two 
to three orders of magnitude lower than the current limit. Based on 
these data, we believe that developments in practices, processes, and 
control technologies warrant revisions to the 1999 MACT rule, under 
section 112(d)(6). Our analysis of emissions data provided in the 
survey conducted by industry indicates that stacks equipped with a 
well-performing fabric filter or ESP can achieve exhaust PM 
concentrations of less than 0.014 lb/ton of glass pulled. We estimate 
that all of the wool fiberglass facilities would be able to comply with 
this revised limit without additional controls. We estimate that this 
would result in small reductions of metal HAP emissions since there 
will only be a couple of facilities subject to the PM limits and the 
available data on some of the furnaces at those facilities indicates 
they are currently meeting the proposed PM emission limit. We do not 
anticipate additional energy use associated with this revised limit. 
Furthermore, we do not anticipate any adverse non-air environmental 
impacts associated with the implementation of this revised limit. 
Therefore, we are proposing that reducing the PM limit in the NESHAP 
from 0.50 lb of PM per ton of glass pulled to 0.014 lb of PM per ton of 
glass pulled (see Table 12) is both feasible and cost effective. 
Therefore, we are proposing a revised PM limit in the NESHAP of 0.014 
lb of PM per ton of glass pulled in this action. We have based these 
statements on information we received from the industry in their survey 
responses; nevertheless, we are seeking comment on our estimation that 
all wool fiberglass manufacturers can meet the PM emission limits 
without additional controls.
    We conducted a review of the available test data for chromium 
compounds including hexavalent chromium emissions from glass furnaces. 
We found that for most furnaces, measured emissions were near or below 
detection limits of the methods used for testing (EPA Method 29 
followed by EPA Method 0061). In contrast, the chromium emissions for a 
few furnaces were several orders of magnitude higher than the rest of 
the industry. The facility emitting the highest level of hexavalent 
chromium, at 840 lb/yr, advised us that the reason chromium tested very 
high was due to the refractory products, high chrome refractories, from 
which the furnaces are constructed (Notes of April 14, 2011, 
Certainteed) \12\. Based on the emissions testing and information on 
high chrome refractories, we believe changes to the 1999 MACT rule are 
warranted under CAA section 112(d)(6).
    The data indicate that well performing wool fiberglass furnaces 
emit small amounts of chromium compounds, that is, they emit less than 
0.06 pounds of chromium compounds (Cr) per thousand tons of glass 
pulled. However, three facilities currently operate furnaces that emit 
chromium in excess of this rate. Chromium emissions from these high 
emitters range from 9 to 840 lb/yr. Furnaces operating below this rate 
generally emit less than 1 pound per year; many of these tested below 
the detection level of the test method. The data indicate that there is 
a `break' between the furnaces emitting less than the proposed limit 
and those emitting greater amounts of chromium. Data further indicate 
there are no wool fiberglass manufacturers with low glass production 
rates but high levels of chrome emissions. We are therefore proposing 
to set a chromium compounds emission limit of 0.06 lb of chromium per 
thousand tons of glass pulled as shown in Table 12.
    Under section 112(d)(6), we are proposing this emission limit for 
chromium compounds taking into account the developments in practices, 
processes and technology by the wool fiberglass industry since 
promulgation of the 1999 MACT standard. The emission limits we are 
proposing for chromium compounds under 112(d)(6) are identical to the 
chromium compounds limits we are proposing under 112(f)(2), as 
described in Section VIII.E of this preamble.
    We estimate that the 2 remaining major source wool fiberglass 
facilities would be able to comply with this chromium compounds 
emission limit. We estimate that if the high chromium emitting 
facilities remain major sources, these new emission limits would result 
in annual reductions of 1,155 pounds of chromium compounds, 
specifically hexavalent chromium and there will be no reductions at the 
remaining facilities because data indicate they are currently meeting 
the proposed chromium emission limit.

[[Page 72804]]

    Wet scrubbers are not generally in use in this industry. However, 
we evaluated their use to achieve reductions in hexavalent chromium for 
furnaces emitting chrome above the levels being proposed. Sodium 
hydroxide (NaOH) scrubbers are in use for furnace operations at other 
industries for chromium compounds reduction. We have evaluated the use 
of NaOH scrubbers for the wool fiberglass manufacturing industry and 
find that the control technology can be adapted for use in the wool 
fiberglass industry from the chromium electroplating industry and from 
certain high temperature metallurgical industries.\42\
---------------------------------------------------------------------------

    \42\ NaOH Scrubber Information. Telephone discussion and emails 
between vendors, companies, and EPA. Steffan Johnson, Measurement 
Policy Group, USEPA/OAQPS/SPPD.
---------------------------------------------------------------------------

    We do anticipate an additional energy use associated with this 
revised limit if sources choose to install NaOH scrubbers to remove 
hexavalent chromium from the furnace gases. We anticipate the affected 
sources may incur disposal costs of hexavalent chromium contaminated 
materials associated with the implementation of this emission limit. We 
anticipate that two sources which currently emit chromium at levels 
slightly higher than the proposed limit will be able to meet it by 
installing NaOH scrubbers (which selectively remove the hexavalent form 
of chromium from the exhaust air). This cost is about $300 per pound 
hexavalent chromium removed if these companies install a NaOH scrubber 
in series with the existing furnace control. A wool fiberglass facility 
could also choose to rebuild the glass furnace using refractories with 
low chromium contents. The cost of that option would be prorated to 
consider the remaining useful life of the existing high chromium 
furnace and would cost about $12,000 per pound chromium compounds 
removed. We expect that for the highest chromium emitting wool 
fiberglass furnace emitting 500 lb chromium per year, this option would 
be used to meet the proposed limit. We base this estimate on two 
factors: (1) The furnace is at the end of its useful life and is 
expected to be reconstructed in 2013 (Notes of April 14, 2011; Region 7 
Certainteed Notes) 12 13 and (2) the NaOH scrubber achieves 
about 95 percent reduction (NaOH Scrubber Information),\42\ which is 
not quite enough to meet the proposed chromium emission limit. The cost 
of the control equipment to wool fiberglass plants is about $225,000 
for installation and annual operation and maintenance costs of about 
$5000 per year. We compared the cost of the controls to the sales or 
revenues of the companies that would incur costs to comply with the 
chromium emission limits. The economic impact on these firms, measured 
in annual compliance costs as a percent of sales or revenues, is less 
than 0.001 percent for each of the affected firms.\43\
---------------------------------------------------------------------------

    \43\ Economic Impact and Initial Regulatory Flexibility 
Analysis. September 2011.
---------------------------------------------------------------------------

    We therefore, we propose that requiring the 0.06 lb chromium per 
thousand tons of melt limit in the NESHAP is both feasible and cost 
effective. We solicit comment on this comparison and the use of this 
value as a reasonable cost to reduce chromium.

 Table 12--Proposed Emissions Limits for Glass-Melting Furnaces Based on
                            Technology Review
------------------------------------------------------------------------
                                                              Pounds
                        Pollutant                          pollutant per
                                                            ton of melt
------------------------------------------------------------------------
PM......................................................         0.14
Chromium compounds......................................         0.00006
------------------------------------------------------------------------

    This proposed limit for chromium compounds (of 0.06 lb per thousand 
tons chromium limit) under CAA Section 112(d)(6) is the same limit 
being proposed under Section 112(f)(2) that was described earlier in 
this notice. We believe that these proposed revisions for chromium and 
PM are cost effective revisions and reflect the current developments in 
processes and technology by this industry. (i.e., well performing air 
pollution control).

IX. Summary of Cost, Environmental, and Economic Impacts for the 
Mineral Wool Source Category

    Here we discuss the anticipated air, water, solid waste and energy 
impacts in addition to the cost and economic impacts to the industry as 
a result of the proposed amendments to the 1999 MACT rule.

A. What are the affected sources in the Mineral Wool Production source 
category?

    We anticipate that the 7 mineral wool production facilities 
currently operating in the United States will be affected by these 
proposed amendments.

B. How are the impacts for this proposal evaluated?

    For the proposed amendments to the Mineral Wool Production source 
category, the air quality, water quality, solid waste, and energy 
impacts were determined based on the need for additional control 
technologies and actions required to meet the proposed emissions 
limits. The Economic Impact Analysis considered annual sales and 
revenue data from the facilities within this source category and their 
ability to meet the proposed amendments. The following sections discuss 
the cost, environmental, and economic impacts to the Mineral Wool 
Production source category. (Economic Impact Analysis for the Mineral 
Wool and Wool Fiberglass RTRs. U.S. EPA. October 2011.)

C. What are the air quality impacts for the Mineral Wool Production 
source category?

    The EPA estimated the emissions reductions that are expected to 
result from the proposed amendments to the 1999 MACT rule compared to 
the 2010 baseline emissions estimates. A detailed documentation of the 
analysis can be found in: Cost Impacts of the Revised NESHAP for the 
Mineral Wool Production Manufacturing Source Category.
    Emissions of formaldehyde from mineral wool production facilities 
have declined over the last 12 years as a result of federal rules, 
state rules and on the industry's own initiative. The current proposal 
would not reduce formaldehyde, phenol, or methanol emissions from their 
current levels. Under the proposed emissions limits for cupolas, COS, 
HF, and HCl emissions would be reduced by a combined 23 percent 
compared to 2010 levels reported in the industry survey responses. We 
estimated that the COS emissions reductions would be 41 tpy from 
cupolas.
    Based on the emissions data available to the EPA, we believe that 
all facilities will be able to comply with the proposed emissions 
limits for COS, HF, HCl, formaldehyde, phenol, and methanol without 
additional controls because they can reduce emissions using raw 
material substitution or oxygen injection as discussed previously in 
Section VII.F of this preamble.

D. What are the water quality and solid waste impacts?

    We do not anticipate any adverse water quality or solid waste 
impacts from the proposed amendments to the 1999 MACT rule because the 
requirements proposed would not change the existing requirements that 
impact water quality or solid waste.

E. What are the secondary impacts?

    Indirect or secondary air quality impacts include impacts that will 
result from the increased electricity usage associated with the 
operation of control

[[Page 72805]]

devices, as well as water quality and solid waste impacts (which were 
just discussed) that might occur as a result of these proposed actions. 
We anticipate that the mineral wool production facilities will be able 
to comply with the proposed amendments without having to install 
additional control technologies such as RTOs. In addition, those 
facilities that switch to low-sulfur raw materials will most likely 
reduce air emissions of SO2.

F. What are the energy impacts?

    Energy impacts in this section are those energy requirements 
associated with the operation of emission control devices. Potential 
impacts on the national energy economy from the rule are discussed in 
the economic impacts section. There would be little national energy 
demand increase from the operation of any of the control options 
analyzed under the proposed NESHAP amendments.

G. What are the cost impacts for the Mineral Wool Production source 
category?

    Each facility was evaluated for its ability to meet the proposed 
emissions limits for PM, COS, HF, and HCl emissions from cupolas and 
formaldehyde, phenol, and methanol emissions from combined collection 
operations and curing designs. The memorandum, Cost Impacts of the 
Revised NESHAP for the Mineral Wool Production Manufacturing Source 
Category, includes a complete description of the cost estimate methods 
used for this analysis and is available in the docket.
    We identified several ways in which mineral wool producers reduce 
the COS emissions from cupolas, enabling them to comply with the 
proposed emission limit of 3.3 lb COS per ton of melt. These methods 
include raw material substitution, oxygen injection, and installation 
of an RTO. We found two approaches to raw material substitution: slag 
and rock. One mineral wool manufacturer purchases low-sulfur slag, a 
waste product from a local steel plant. Another plant owns and operates 
a local quarry from which they obtain rock that does not contain 
sulfur. The low-sulfur slag or rock is used in the cupola in place of 
high-sulfur slag. Because sulfur is not added into the cupola with the 
raw materials, it is not emitted as sulfur compounds from the stack in 
the form of COS or SO2 during production. As shown in their 
title V permit, another plant uses oxygen injection to accelerate the 
reaction of COS to CO2 and SO2, thereby reducing 
that company's COS emissions.
    However, most mineral wool plants have installed regenerative 
thermal oxidizers to convert the high concentrations of COS in the 
cupola exhaust gas to energy that is returned to the cupola. This 
technology reduces the consumption of coke up to 30 percent and, 
because of the cost of coke, this technology pays for itself over a 
period of several years. Emissions of COS are below 0.04 lb COS per ton 
melt when an RTO is installed for energy reclamation and new source 
MACT is based upon the use of this technology.
    One facility is expected to incur an incremental annualized cost of 
$360,000 for low-sulfur raw materials (rock) if they use that option to 
comply with the COS requirement for cupolas. That cost would be 
lessened to no more than $20,000 for installation of oxygen injection, 
which is another alternative. We do not anticipate this plant would 
install an RTO to comply with the rule. The total industry-wide costs 
for monitoring for COS, HF, and HCl from the cupolas is $146,000, while 
the total costs for monitoring for formaldehyde, phenol, and methanol 
from the combined collection and curing operations is $42,000.
    The total annualized costs for the proposed rule are estimated at 
$548,000 (2010 dollars). Table 13 provides a summary of the estimated 
costs and emissions reductions associated with the proposed amendments 
to the Mineral Wool Production NESHAP presented in this action.

   Table 13--Estimated Costs and Reductions for the Mineral Wool Production Proposed Standards in This Action
----------------------------------------------------------------------------------------------------------------
                                                                                     Total HAP         Cost
                                                     Estimated       Estimated       emissions     effectiveness
               Proposed amendment                  capital cost     annual cost     reductions     in $ per ton
                                                       ($MM)           ($MM)         (tons per       total HAP
                                                                                       year)         reduction
----------------------------------------------------------------------------------------------------------------
COS limit; Low-Sulfur Materials.................               0           0.360              41           8,780
Additional testing and monitoring...............               0           0.243             N/A             N/A
----------------------------------------------------------------------------------------------------------------

H. What are the economic impacts for the Mineral Wool Production source 
category?

    We performed an economic impact analysis for mineral wool producers 
nationally using the annual compliance costs estimated for this 
proposed rule.(Economic Impact and Initial Regulatory Flexibility 
Analysis. October 2011).\43\ The impacts to most producers affected by 
this proposed rule are annualized costs of less than one percent of 
their revenues using the most current year available for revenue data. 
One producer will experience an annualized cost of 6.7 percent of its 
revenue, however. Both demand and supply in this sector are inelastic 
to price changes. Thus, if producers could pass through the entire cost 
of the rule to consumers, we would expect prices to increase by less 
than one percent, with no change in output. Conversely, if producers 
could not pass through any of the cost by increasing the price, we 
would expect output to decline by less than one percent.
    Hence, the overall economic impact of this proposed rule should be 
low on most of the affected industry and its consumers. For more 
information, please refer to the Economic Impact Analysis for this 
proposed rulemaking that is available in the public docket. Id.

I. What are the benefits for the Mineral Wool Production source 
category?

    The proposed Mineral Wool Production NESHAP amendments are expected 
to result in approximately 23 percent reduction in COS; HF, and HCl are 
not reduced. We have not quantified the monetary benefits associated 
with these reductions.

J. What demographic groups might benefit the most from this regulation?

    The worst-case nature of our acute screening assessment suggests 
that the potential for adverse effects carries a relatively low 
probability of occurrence. The EPA concludes that, based on our 
analyses, the risks associated with MACT-allowable and actual emissions 
(primarily due to formaldehyde emissions from stacks) from this source 
category are acceptable. Thus, a demographic analysis was not 
conducted.

[[Page 72806]]

X. Summary of Cost, Environmental, and Economic Impacts for the Wool 
Fiberglass Manufacturing Source Category

A. What are the affected sources in the Wool Fiberglass Manufacturing 
source category?

    We evaluated the impacts to the affected sources based on all 
available information, including two significant sources: the 2010 
emissions testing and subsequent conversations with NAIMA and 
individuals operating industry facilities. According to the 2010 
emissions test data, there are 3 furnaces at 3 facilities that do not 
meet this proposed chromium emission limit. In their responses to the 
survey conducted by the industry, facilities stated the tested furnaces 
were representative of the untested furnaces. However, furnace 
construction materials (refractory composition) were not one of the 
factors considered in determining representativeness.
    After the completion of the survey conducted by industry, we 
received information that emissions testing for chromium may not 
necessarily be representative of other furnaces that were not tested. 
Therefore, we based our assessment of the impacts upon the tested 
furnaces only, and did not include in that assessment untested 
furnaces.
    Based on this approach, we anticipate that all 29 wool fiberglass 
manufacturing facilities currently operating in the United States will 
be affected by these proposed amendments, 2 of the 29 wool fiberglass 
manufacturing facilities currently operating in the United States will 
install air pollution controls, and that one facility will reconstruct 
a furnace to comply with these proposed amendments. Additionally, 
industry has stated that no major wool fiberglass residential 
insulation sources will still exist in this source category by the time 
the proposed rules are promulgated. If their predictions come to pass, 
we estimate that two facilities will be affected by these proposed 
amendments; these are pipe insulation facilities. However, any major 
sources still in operation at the time the amendments are promulgated 
will be affected by this rule. One new facility was recently built, but 
no facilities are expected to be constructed in the foreseeable future.

B. How are the impacts for this proposal evaluated?

    For the proposed Wool Fiberglass Manufacturing NESHAP amendments, 
the air quality, water quality, solid waste, and energy impacts were 
determined based on the need for additional control technologies and 
actions required to meet the proposed emissions limits. The Economic 
Impact Analysis considered annual sales and revenue data from the 
facilities within this source category and their ability to meet the 
proposed amendments. The following sections discuss the cost, 
environmental, and economic impacts to the Wool Fiberglass 
Manufacturing source category. (Economic Impact Analysis for the 
Mineral Wool and Wool Fiberglass RTRs. U.S. EPA. October 2011.)

C. What are the air quality impacts?

    The EPA estimated the emissions reductions that are expected to 
result from the proposed amendments to the 1999 MACT rule compared to 
the 2010 baseline emissions estimates. A detailed documentation of the 
analysis can be found in: Cost Impacts of the Revised NESHAP for the 
Wool Fiberglass Manufacturing Source Category. We expect reductions of 
formaldehyde, phenol and methanol, and chromium compounds.
    Emissions of formaldehyde, PM, and HAP metals from wool fiberglass 
manufacturing have declined over the last 12 years as a result of 
federal rules, state rules and on the industry's own initiative. The 
current proposal is expected to yield emission reductions for 
formaldehyde, phenol, and methanol from their current levels. However, 
the proposed amendments are expected to discourage facilities in the 
wool fiberglass industry from reintroducing formaldehyde to their 
production lines. In addition, the proposed chromium compound emission 
limit would prevent emissions of chromium compounds in the future and 
discourage the replacement of currently operating furnaces with those 
constructed of high chromium refractory bricks.
    Based on the emissions data available to the EPA, we believe that 
all affected facilities will be able to comply with the proposed 
emissions limits for formaldehyde, phenol, methanol, HF, and HCl 
without additional controls. Additional controls are required for major 
sources with high-chrome refractories. Additionally, as discussed in 
Section X.J of this preamble, the EPA has determined that the proposed 
rule will not have disproportionately high and adverse human health or 
environmental effects on minority or low-income populations.

D. What are the water quality and solid waste impacts?

    We anticipate water quality and solid waste impacts may result from 
the disposal of high chrome refractories in landfills or in other areas 
that are not designed or permitted to receive hexavalent chromium 
waste. Water quality and solid waste impacts are also possible from 
potential reuse of spent high chrome refractory products. Because of 
their durability, we believe that use of refractory bricks made with 
high chrome content are becoming widespread,\44\ (Chromium in 
Refractories),\11\ as their use can nearly double the life of glass 
furnaces (Notes of April 14, 2011, Certainteed; Region 7 Certainteed 
Notes; August 31, 2011 Meeting).12 13 35 When glass furnaces 
reach the end of their useful life and must be rebuilt, the high chrome 
refractory brick from demolition of the old furnace is typically 
discarded, as it typically cannot be used in new furnace construction. 
As for any industrial waste, the bricks from an old glass furnace 
would, when discarded, potentially be subject to the Resource 
Conservation and Recovery Act (RCRA) and its regulations.
---------------------------------------------------------------------------

    \44\ Excel spreadsheet provided by North American Insulation 
Manufacturers Association (NAIMA). Non-CBI NAIMA Response to Cr 
Emissions 8.11.11.
---------------------------------------------------------------------------

    Additionally, NaOH scrubber solids are expected to contain high 
levels of hexavalent chromium removed from furnace emissions. The 
proper disposal procedures for hexavalent chromium-contaminated waste 
are provided under RCRA regulations (40 CFR 262.11).

E. What are the secondary impacts?

    Indirect or secondary air quality impacts include impacts that will 
result from the increased electricity usage associated with the 
operation of control devices, as well as water quality and solid waste 
impacts that might occur as a result of these proposed actions. We 
estimate the proposed amendments will not result in any significant 
secondary impacts from the requirements of the Mineral Wool MACT 
amendments because facilities can meet the COS limits without 
installing RTOs. We do not anticipate significant secondary impacts 
from the proposed amendments to the Wool Fiberglass MACT.

F. What are the energy impacts?

    Energy impacts in this section are those energy requirements 
associated with the operation of emission control devices. Potential 
impacts on the national energy economy from the proposed amendments to 
the Wool Fiberglass MACT are expected to be minimal and will not result 
in a significant increase in national energy demand.

[[Page 72807]]

G. What are the cost impacts?

    The capital costs for each facility were estimated based on the 
ability for each facility to meet the proposed emissions limits for PM, 
chromium compounds, HF, HCl, formaldehyde, phenol, and methanol. The 
memorandum, Cost Impacts of the Revised NESHAP for the Wool Fiberglass 
Manufacturing Source Category, includes a complete description of the 
cost estimate methods used for this analysis and is available in the 
docket. Under the proposed amendments, the majority of wool fiberglass 
facilities are not expected to incur any capital costs to comply with 
the proposed emissions limits. The total costs estimated for compliance 
with the amendments proposed in this action are $60,000 for compliance 
testing on glass-melting furnaces and $52,000 for compliance testing on 
the FA manufacturing line for pipe insulation products. The total 
annualized costs for the proposed rule are estimated at $112,000 (2010 
dollars). Table 14 provides a summary of the costs and emission 
reductions associated with the proposed amendments if the three 
facilities with high levels of hexavalent chromium install controls or 
reconstruct furnaces to meet the emission limits of the proposed rule. 
Because the industry is undergoing the phaseout of HAP binders, no 
major sources are expected to exist by the compliance deadline for this 
proposed rule, and no costs to industry beyond testing would be 
incurred. However, in the event that the three facilities that do not 
now meet the chromium compounds limit were to remain major sources, we 
estimated the annualized control costs as between $100,000 to $300,000 
per furnace, depending on which of two options is used. Nine hundred 
seventy (970) pounds of chromium compounds per year would be reduced at 
three major sources in the industry, 913 pounds of this from a single 
facility. Hexavalent chromium is 92% of the total chromium compounds 
emitted from wool fiberglass furnaces. Actual facility costs would be 
determined by the number of furnaces, the associated level of Cr 
emissions, and the major source status of the facility.

Table 14--Estimated Costs and Reductions for the Proposed Wool Fiberglass Manufacturing Standards in This Action
----------------------------------------------------------------------------------------------------------------
                                                                     Total HAP
                                                                     emissions         Cost
       Proposed amendment          Est. capital     Est. annual     reductions     effectiveness     Number of
                                    cost ($MM)      cost ($MM)      (pounds per   in $ per pound    facilities
                                                                       year)
----------------------------------------------------------------------------------------------------------------
Change out of refractory brick               6.0             0.3             900             333               1
 lining.........................
Installation of NaOH scrubber...            0.25             0.1              70            1400               2
Additional testing and                         0            0.06             N/A             N/A  ..............
 monitoring for glass-melting
 furnaces.......................
Additional testing and                         0           0.052             N/A             N/A  ..............
 monitoring for FA lines for
 pipe insulation products.......
----------------------------------------------------------------------------------------------------------------

H. What are the economic impacts?

    We performed an economic impact analysis for the wool fiberglass 
industry using the annual compliance costs estimated for this proposed 
rule (Economic Impact and Initial Regulatory Flexibility Analysis for 
the Proposed Mineral Wool and Wool Fiberglass Risk and Technology 
Review).\43\ The impacts to producers affected by this proposed rule 
are annualized costs of less than 0.1 percent of their revenues using 
the most current year available for revenue data. With the 
responsiveness of wool fiberglass demand and supply at less than 1:1 
compared to a price change, and with the change in product price as 
approximated by the cost to revenue ratio at less than 0.1 percent, for 
this ratio is the maximum price change that producers may face, it is 
expected that wool fiberglass price and output changes will be less 
than 0.1 percent. Hence, the overall economic impact of this proposed 
rule should be low on the affected industry and its consumers. For more 
information, please refer to the Economic Impact Analysis for this 
proposed rulemaking that is available in the public docket. (Economic 
Impact Analysis for the Mineral Wool and Wool Fiberglass RTRs. U.S. 
EPA. October 2011.)

I. What are the benefits?

    As stated in section X.C., we expect emissions reductions of PM, 
phenol, formaldehyde, methanol, and chromium compounds. We have not 
quantified the monetary benefits associated with these reductions.

J. What demographic groups might benefit the most from this regulation?

    For the proposed wool fiberglass rule, the EPA has determined that 
the current health risks posed to anyone by emissions from this source 
category are acceptable. However, there are about 849,000 people 
nationwide that are currently subject to health risks which are non-
negligible (i.e., cancer risks greater than 1-in-1 million) due to 
emissions from this source category. We performed an analysis of the 
demographic makeup of these 849,000 people. The demographic 
distribution of this ``at-risk'' population is similar to the national 
distribution of demographics for all groups except for the ``minority'' 
group (defined as total population minus the white population), which 
is 11 percent greater than its corresponding national percentage. See 
the Risk and Technology Review--Analysis of Socio-Economic Factors for 
Populations Living Near Wool Fiberglass Facilities in the docket for 
additional details on the demographic analysis.
    The EPA has determined that the current health risks posed to 
anyone by emissions from this source category are acceptable. 
Therefore, the EPA has determined that the proposed rule will not have 
disproportionately high and adverse human health or environmental 
effects on minority or low-income populations.

XI. Request for Comments

    We are soliciting comments on all aspects of this proposed action. 
All comments received during the comment period will be considered. In 
addition to general comments on this proposed action, we are also 
interested in any additional data that may help to address emissions of 
chromium compounds from wool fiberglass manufacturing furnaces, such as 
speciation of the different types of chromium compounds that may be 
used in the manufacture of refractory bricks, shapes, and castables; 
and the properties of different chromium compounds when exposed to 
temperatures exceeding 1500[deg]C.

[[Page 72808]]

Specifically, we are interested in data we can use to support any of 
the proposed alternatives and new data that could support an 
alternative not proposed in these actions. We are also interested in 
additional data that may help to reduce the uncertainties inherent in 
the risk assessments and other analyses. We are specifically interested 
in receiving corrections to the site-specific emissions profiles used 
for risk modeling. Such data should include supporting documentation in 
sufficient detail to allow characterization of the quality and 
representativeness of the data or information. Section VII of this 
preamble provides more information on submitting data.

XII. Submitting Data Corrections

    The site-specific emissions profiles used in the source category 
risk and demographic analyses are available for download on the RTR web 
page at: http://www.epa.gov/ttn/atw/rrisk/rtrpg.html. The data files 
include detailed information for each HAP emissions release point for 
the facility included in the source category.
    If you believe that the data are not representative or are 
inaccurate, please identify the data in question, provide your reason 
for concern, and provide any ``improved'' data that you have, if 
available. When you submit data, we request that you provide 
documentation of the basis for the revised values to support your 
suggested changes. To submit comments on the data downloaded from the 
RTR Web page, complete the following steps:
    1. Within this downloaded file, enter suggested revisions to the 
data fields appropriate for that information. The data fields that may 
be revised include the following:

------------------------------------------------------------------------
         Data element                          Definition
------------------------------------------------------------------------
Control Measure..............  Are control measures in place? (yes or
                                no).
Control Measure Comment......  Select control measure from list
                                provided, and briefly describe the
                                control measure.
Delete.......................  Indicate here if the facility or record
                                should be deleted.
Delete Comment...............  Describes the reason for deletion.
Emissions Calculation Method   Code description of the method used to
 Code For Revised Emissions.    derive emissions. For example, CEM,
                                material balance, stack test, etc.
Emissions Process Group......  Enter the general type of emissions
                                process associated with the specified
                                emissions point.
Fugitive Angle...............  Enter release angle (clockwise from true
                                North); orientation of the y-dimension
                                relative to true North, measured
                                positive for clockwise starting at 0
                                degrees (maximum 89 degrees).
Fugitive Length..............  Enter dimension of the source in the east-
                                west (x-) direction, commonly referred
                                to as length (ft).
Fugitive Width...............  Enter dimension of the source in the
                                north-south (y-) direction, commonly
                                referred to as width (ft).
Malfunction Emissions........  Enter total annual emissions due to
                                malfunctions (tpy).
Malfunction Emissions Max      Enter maximum hourly malfunction
 Hourly.                        emissions here (lb/hr).
North American Datum.........  Enter datum for latitude/longitude
                                coordinates (NAD27 or NAD83); if left
                                blank, NAD83 is assumed.
Process Comment..............  Enter general comments about process
                                sources of emissions.
REVISED Address..............  Enter revised physical street address for
                                MACT facility here.
REVISED City.................  Enter revised city name here.
REVISED County Name..........  Enter revised county name here.
REVISED Emissions Release      Enter revised Emissions Release Point
 Point Type.                    Type here.
REVISED End Date.............  Enter revised End Date here.
REVISED Exit Gas Flow Rate...  Enter revised Exit Gas Flowrate here (ft
                                \3\/sec).
REVISED Exit Gas Temperature.  Enter revised Exit Gas Temperature here
                                (F).
REVISED Exit Gas Velocity....  Enter revised Exit Gas Velocity here (ft/
                                sec).
REVISED Facility Category      Enter revised Facility Category Code
 Code.                          here, which indicates whether facility
                                is a major or area source.
REVISED Facility Name........  Enter revised Facility Name here.
REVISED Facility Registry      Enter revised Facility Registry
 Identifier.                    Identifier here, which is an ID assigned
                                by the EPA Facility Registry System.
REVISED HAP Emissions          Enter revised HAP Emissions Performance
 Performance Level Code.        Level here.
REVISED Latitude.............  Enter revised Latitude here (decimal
                                degrees).
REVISED Longitude............  Enter revised Longitude here (decimal
                                degrees).
REVISED MACT Code............  Enter revised MACT Code here.
REVISED Pollutant Code.......  Enter revised Pollutant Code here.
REVISED Routine Emissions....  Enter revised routine emissions value
                                here (tpy).
REVISED SCC Code.............  Enter revised SCC Code here.
REVISED Stack Diameter.......  Enter revised Stack Diameter here (ft).
REVISED Stack Height.........  Enter revised Stack Height here (ft).
REVISED Start Date...........  Enter revised Start Date here.
REVISED State................  Enter revised State here.
REVISED Tribal Code..........  Enter revised Tribal Code here.
REVISED Zip Code.............  Enter revised Zip Code here.
Shutdown Emissions...........  Enter total annual emissions due to
                                shutdown events (tpy).
Shutdown Emissions Max Hourly  Enter maximum hourly shutdown emissions
                                here (lb/hr).
Stack Comment................  Enter general comments about emissions
                                release points.
Startup Emissions............  Enter total annual emissions due to
                                startup events (tpy).
Startup Emissions Max Hourly.  Enter maximum hourly startup emissions
                                here (lb/hr).
Year Closed..................  Enter date facility stopped operations.
------------------------------------------------------------------------


[[Page 72809]]

    2. Fill in the commenter information fields for each suggested 
revision (i.e., commenter name, commenter organization, commenter email 
address, commenter phone number, and revision comments).
    3. Gather documentation for any suggested emissions revisions 
(e.g., performance test reports, material balance calculations).
    4. Send the entire downloaded file with suggested revisions in 
Microsoft[supreg] Access format and all accompanying documentation to 
Docket ID Number EPA-HQ-OAR-2010-1041 for the Mineral Wool Production 
source category and Docket ID number EPA-HQ-OAR-2010-1042 for the Wool 
Fiberglass Manufacturing source category (through one of the methods 
described in the ADDRESSES section of this preamble). To expedite 
review of the revisions, it would also be helpful if you submitted a 
copy of your revisions to the EPA directly at [email protected] in addition 
to submitting them to the docket.
    5. If you are providing comments on a facility, you need only 
submit one file for that facility, which should contain all suggested 
changes for all sources at that facility. We request that all data 
revision comments be submitted in the form of updated Microsoft[reg] 
Access files, which are provided on the RTR Web Page at: http://www.epa.gov/ttn/atw/rrisk/rtrpg.html.

XIII. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive 
Order 13563: Improving Regulation and Regulatory Review

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this 
action is a significant regulatory action because it raises novel legal 
and policy issues. Accordingly, the EPA submitted this action to the 
Office of Management and Budget (OMB) for review under Executive Orders 
12866 and 13563 (76 FR 3821, January 21, 2011) and any changes made in 
response to OMB recommendations have been documented in the docket for 
this action.

B. Paperwork Reduction Act

    The information collection requirements in this rule have been 
submitted for approval to the OMB under the Paperwork Reduction Act, 44 
U.S.C. 3501 et seq. The Information Collection Request (ICR) documents 
prepared by the EPA have been assigned EPA ICR numbers 1799.06 for 
Mineral Wool Production and 1160.10 for Wool Fiberglass Manufacturing. 
The information collection requirements are not enforceable until OMB 
approves them. The information requirements are based on notification, 
recordkeeping, and reporting requirements in the NESHAP General 
Provisions (40 CFR part 63, subpart A), which are mandatory for all 
operators subject to national emissions standards. These recordkeeping 
and reporting requirements are specifically authorized by CAA section 
114 (42 U.S.C. 7414). All information submitted to the EPA pursuant to 
the recordkeeping and reporting requirements for which a claim of 
confidentiality is made is safeguarded according to agency policies set 
forth in 40 CFR part 2, subpart B.
    For this proposed rule, the EPA is adding affirmative defense to 
the estimate of burden in the ICRs. To provide the public with an 
estimate of the relative magnitude of the burden associated with an 
assertion of the affirmative defense position adopted by a source, the 
EPA has provided administrative adjustments to these ICRs to show what 
the notification, recordkeeping and reporting requirements associated 
with the assertion of the affirmative defense might entail. The EPA's 
estimate for the required notification, reports and records for any 
individual incident totals $3,141 and is based on the time and effort 
required of a source to review relevant data, interview plant 
employees, and document the events surrounding a malfunction that has 
caused an exceedance of an emissions limit. The estimate also includes 
time to produce and retain the record and reports for submission to the 
EPA. The EPA provides this illustrative estimate of this burden because 
these costs are only incurred if there has been a violation and a 
source chooses to take advantage of the affirmative defense.
    Given the variety of circumstances under which malfunctions could 
occur, as well as differences among sources' operation and maintenance 
practices, we cannot reliably predict the severity and frequency of 
malfunction-related excess emissions events for a particular source. It 
is important to note that the EPA has no basis currently for estimating 
the number of malfunctions that would qualify for an affirmative 
defense. Current historical records would be an inappropriate basis, as 
source owners or operators previously operated their facilities in 
recognition that they were exempt from the requirement to comply with 
emissions standards during malfunctions. Of the number of excess 
emissions events reported by source operators, only a small number 
would be expected to result from a malfunction (based on the definition 
above), and only a subset of excess emissions caused by malfunctions 
would result in the source choosing to assert the affirmative defense. 
Thus, we believe the number of instances in which source operators 
might be expected to avail themselves of the affirmative defense will 
be extremely small. For this reason, we did not estimate any such 
occurrences for all sources subject to subparts DDD and NNN over the 3-
year period covered by these ICRs. We expect to gather information on 
such events in the future and will revise this estimate as better 
information becomes available.
    We estimate 7 regulated entities are currently subject to subpart 
DDD and will be subject to all proposed standards. The annual 
monitoring, reporting, and recordkeeping burden for this collection 
(averaged over the first 3 years after the effective date of the 
standards) for these amendments to subpart DDD (Mineral Wool 
Production) is estimated to be $85,348 per year. This estimate includes 
performance tests, notifications, reporting, and recordkeeping 
associated with the new requirements for COS, HF, and HCl from cupolas 
and formaldehyde, phenol, and methanol from combined collection and 
curing oven designs. The total burden for the Federal government 
(averaged over the first 3 years after the effective date of the 
standard) is estimated to be 22 hours per year at a total labor cost of 
$970 per year. Burden is defined at 5 CFR 1320.3(b).
    We estimate 29 regulated entities are currently subject to subpart 
NNN and only 2 will be subject to all proposed standards. The annual 
monitoring, reporting, and recordkeeping burden for this collection 
(averaged over the first 3 years after the effective date of the 
standards) for these amendments to subpart NNN (Wool Fiberglass 
Manufacturing) is estimated to be $14,000 per year. This estimate 
includes performance tests, notifications, reporting, and recordkeeping 
associated with the new requirements for PM, chromium compounds, HF, 
and HCl from glass-melting furnaces and formaldehyde, phenol, and 
methanol from both RS and FA manufacturing lines. The total burden for 
the Federal government (averaged over the first 3 years after the 
effective date of the standard) is estimated to be 6.3 hours per year 
at a total labor cost of $283 per year.
    An agency may not conduct or sponsor, and a person is not required 
to respond to, a collection of information

[[Page 72810]]

unless it displays a currently valid OMB control number. The OMB 
control numbers for the EPA's regulations in 40 CFR are listed in 40 
CFR part 9. When these ICRs are approved by OMB, the agency will 
publish a technical amendment to 40 CFR part 9 in the Federal Register 
to display the OMB control numbers for the approved information 
collection requirements contained in the final rules.
    To comment on the agency's need for this information, the accuracy 
of the provided burden estimates, and any suggested methods for 
minimizing respondent burden, the EPA has established a public docket 
for this rule, which includes this ICR, under Docket ID number EPA-HQ-
OAR-2010-1041 for the Mineral Wool Production source category and 
Docket ID number EPA-HQ-OAR-2010-1042 for the Wool Fiberglass 
Manufacturing source category. Submit any comments related to the ICRs 
to the EPA and the OMB. See the ADDRESSES section at the beginning of 
this notice for where to submit comments to the EPA. Send comments to 
the OMB at the Office of Information and Regulatory Affairs, Office of 
Management and Budget, 725 17th Street NW., Washington, DC 20503, 
Attention: Desk Office for the EPA. Since the OMB is required to make a 
decision concerning the ICR between 30 and 60 days after November 25, 
2011, a comment to OMB is best assured of having its full effect if the 
OMB receives it by December 27, 2011. The final rule will respond to 
any OMB or public comments on the information collection requirements 
contained in this proposal.

C. Regulatory Flexibility Act

    The 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 impacts of this proposed rule on 
small entities, small entity is defined as: (1) A small business as 
defined by the SBA's 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 that is independently owned and operated and is not dominant 
in its field. For this source category, which has the NAICS code 327993 
(i.e., Mineral Wool Production and Wool Fiberglass Manufacturing), the 
SBA small business size standard is 500 employees according to the SBA 
small business standards definitions.
    After considering the economic impacts of this proposed rule on 
small entities in the Mineral Wool Production and Wool Fiberglass 
Manufacturing source categories, I certify that this action will not 
have a significant economic impact on a substantial number of small 
entities. Five of the 6 Mineral Wool Production parent companies 
affected are considered to be small entities per the definition 
provided in this section. However, we estimate that this proposed 
action will not have a significant economic impact on those companies. 
The impact of this proposed action on these companies will be an 
annualized compliance cost of less than one percent of its revenues. 
Only one of the five small parent companies is expected to have an 
annualized compliance cost of greater than one percent of its revenues. 
All other affected parent companies are not small businesses according 
to the SBA small business size standard for the affected NAICS code 
(NAICS 327993). One Wool Fiberglass Manufacturing facility is 
considered to be owned by a small business, but this facility will not 
experience an impact from this proposed rule. We have determined that 
the impacts do not constitute a significant economic impact on a 
substantial number of small entities in the Wool Fiberglass 
Manufacturing source category (See: Economic Impact and Small Business 
Analysis for the proposed Mineral Wool and Wood Fiberglass Production 
Source Categories NESHAP).
    Although this proposed rule will not have a significant economic 
impact on a substantial number of small entities, the EPA nonetheless 
has tried to reduce the impact of this rule on small entities. For more 
information, please refer to the economic impact and small business 
analysis that is in the docket. We continue to be interested in the 
potential impacts of the proposed rule on small entities and welcome 
comments on issues related to such impacts.

D. Unfunded Mandates Reform Act

    This proposed rule does not contain a Federal mandate under the 
provisions of Title II of the UMRA of 1995, 2 U.S.C. 1531-1538 for 
State, local, or Tribal governments or the private sector. The proposed 
rule would not result in expenditures of $100 million or more for 
State, local, and Tribal governments, in aggregate, or the private 
sector in any 1 year. The proposed rule imposes no enforceable duties 
on any State, local or Tribal governments or the private sector. Thus, 
this proposed rule is not subject to the requirements of sections 202 
or 205 of the UMRA.
    This proposed rule 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 because it 
contains no requirements that apply to such governments nor does it 
impose obligations upon them.

E. Executive Order 13132: Federalism

    This proposed rule 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. None of the facilities subject 
to this action are owned or operated by State governments, and, because 
no new requirements are being promulgated, nothing in this proposed 
rule will supersede State regulations. Thus, Executive Order 13132 does 
not apply to this proposed rule.
    In the spirit of Executive Order 13132, and consistent with the EPA 
policy to promote communications between the EPA and State and local 
governments, the EPA specifically solicits comment on this proposed 
rule from State and local officials.

F. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    This proposed rule does not have Tribal implications, as specified 
in Executive Order 13175 (65 FR 67249, November 9, 2000). Thus, 
Executive Order 13175 does not apply to this action.
    The EPA specifically solicits additional comment on this proposed 
action from Tribal officials.

G. Executive Order 13045: Protection of Children From Environmental 
Health Risks and Safety Risks

    This proposed rule 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.

[[Page 72811]]

H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use

    This action is not a ``significant energy action'' as defined under 
Executive Order 13211, ``Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use'' (66 FR 
28355, May 22, 2001), because it is not likely to have significant 
adverse effect on the supply, distribution, or use of energy. This 
action will not create any new requirements and therefore no additional 
costs for sources in the energy supply, distribution, or use sectors.

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (NTTAA), Public Law No. 104-113 (15 U.S.C. 272 note), 
directs the EPA to use 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 voluntary consensus standards bodies. NTTAA directs the EPA 
to provide Congress, through OMB, explanations when the agency decides 
not to use available and applicable VCS.
    The proposed rule involves technical standards. Therefore, the 
requirements of the NTTAA apply to this action. We conducted searches 
for the RTR for the Mineral Wool Production and Wool Fiberglass 
Manufacturing NESHAP through the Enhanced NSSN Database managed by the 
American National Standards Institute (ANSI). We also contacted VCS 
organizations and accessed and searched their databases.
    Under 40 CFR part 63 subpart DDD, searches were conducted for EPA 
Methods 5, 318, and 320 of 40 CFR Part 60, Appendix A. Under 40 CFR 
part 63 subpart NNN, searches were conducted for EPA Methods 5, 318, 
320, 29, and 0061 of 40 CFR Part 60, Appendix A. No applicable 
voluntary consensus standards were identified for EPA Method 318 and 
SW-846 Method 0061.
    One voluntary consensus standard ASTM D6348-03 (2010), 
Determination of Gaseous Compounds by Extractive Direct Interface 
Fourier Transform (FTIR) Spectroscopy is acceptable as an alternative 
to Method 320 for both subparts DDD and NNN, but with several 
conditions: (1) The test plan preparation and implementation in the 
Annexes to ASTM D6348-03, Sections A1 through A8 are mandatory; and (2) 
In ASTM D6348-03 Annex A5 (Analyte Spiking Technique), the percent R 
(percent R) must be determined for each target analyte (Equation A5.5). 
In order for the test data to be acceptable for a compound, percent R 
must be 70 percent >= R <= 130 percent. If the percent R value does not 
meet the criterion for a target compound, the test data is not 
acceptable for that compound and the test must be repeated for that 
analyte (i.e., the sampling and/or analytical procedure should be 
adjusted before a retest). The percent R value for each compound must 
be reported in the test report, and all field measurements must be 
corrected with the calculated percent R value for that compound by 
using the following equation: Reported Result = (Measured Concentration 
in the Stack x 100)/percent R.
    In addition, ASTM D6784-02 (2008), Standard Test Method for 
Elemental, Oxidized, Particle-Bound and Total Mercury Gas Generated 
from Coal-Fired Stationary Sources (Ontario Hydro Method) is acceptable 
as an alternative to Method 29 in the subpart NNN rule.
    The search identified four other VCS that were potentially 
applicable for the Mineral Wool Production rule in lieu of EPA 
reference methods. However, after reviewing the available standards, 
EPA determined that four candidate VCS (ASTM D3685/D3685M-98 [2005], 
ISO 9096:1992 [2003], CAN/CSA Z223.1-M1977, ANSI/ASME PTC 38 1980 
[1985]) identified for measuring emissions of pollutants or their 
surrogates subject to emission standards in the rule would not be 
practical due to lack of equivalency, documentation, validation data 
and other important technical and policy considerations.
    Under the Wool Fiberglass rule, the search identified six other VCS 
that were potentially applicable in lieu of EPA reference methods (EN 
13211:2001, CAN/CSA Z223.26-M1986, ASTM D3685/D3685M-98 [2005], ISO 
9096:1992 [2003], CAN/CSA Z223.1-M1977, and ANSI/ASME PTC 38 1980 
[1985]). However, the EPA determined that these methods would not be 
practical due to lack of equivalency, documentation, validation data 
and other important technical and policy considerations.
    The VCS searches are documented in the Voluntary Consensus Standard 
Results for the Risk and Technology Review for the Mineral Wool NESHAP 
and the Voluntary Consensus Standard Results for the Risk and 
Technology Review for the Wool Fiberglass NESHAP memorandums as 
provided in the docket.
    The EPA welcomes comments on this aspect of the proposed rulemaking 
and, specifically, invites the public to identify potentially-
applicable VCS and to explain why such standards should be used in this 
regulation.

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 EJ. Its main provision directs federal 
agencies, to the greatest extent practicable and permitted by law, to 
make EJ 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.
    For the proposed mineral wool rule, the EPA has determined that the 
rule will not have disproportionately high and adverse human health or 
environmental effects on minority or low-income populations, because it 
increases the level of environmental protection for all affected 
populations without having any disproportionately high and adverse 
human health or environmental effects on any population, including any 
minority or low-income population.
    For the proposed wool fiberglass rule, the EPA has determined that 
the current health risks posed to anyone by emissions from this source 
category are acceptable. Therefore, the EPA has determined that the 
proposed rule will not have disproportionately high and adverse human 
health or environmental effects on minority or low-income populations.

List of Subjects in 40 CFR Part 63

    Environmental protection, Air pollution control, Incorporation by 
reference, Mineral wool, Wool fiberglass, Reporting and recordkeeping 
requirements.

    Dated: November 4, 2011.
Lisa P. Jackson,
Administrator.

    For the reasons stated in the preamble, part 63 of title 40, 
chapter I, of the Code of Federal Regulations is proposed to be amended 
as follows:

PART 63--[AMENDED]

    1. The authority citation for part 63 continues to read as follows:

    Authority:  42 U.S.C. 7401, et seq.

[[Page 72812]]

Subpart DDD--[Amended]

    2. Section 63.1178 is amended by revising paragraph (a)(2) and 
adding paragraphs (a)(3) and (4) to read as follows:


Sec.  63.1178  For cupolas, what standards must I meet?

* * * * *
    (a) * * *
    (2) Limit emissions of carbonyl sulfide (COS) from each existing, 
new, or reconstructed cupola to the following:
    (i) 3.3 lb of COS per ton of melt or less for existing cupolas.
    (ii) 0.017 lb of COS per ton of melt or less for new or 
reconstructed cupolas.
    (3) Limit emissions of hydrogen fluoride (HF) from each existing, 
new, or reconstructed cupola to 0.014 lb of HF per ton of melt or less.
    (4) Limit emissions of hydrogen chloride (HCl) from each existing, 
new, or reconstructed cupola to 0.0096 lb of HCl per ton of melt or 
less.
* * * * *
    3. Section 63.1179 is amended by revising the section heading and 
paragraphs (a) and (b) introductory text to read as follows:


Sec.  63.1179  For combined collection/curing operations, what 
standards must I meet?

    (a) You must control emissions from each existing and new combined 
collection/curing operations by limiting emissions of formaldehyde, 
phenol, and methanol to the following:
    (1) For combined drum collection/curing operations:
    (i) 0.067 lb of formaldehyde per ton of melt or less,
    (ii) 0.0023 lb of phenol per ton of melt or less, and
    (iii) 0.00077 lb of methanol per ton of melt or less.
    (2) For combined horizontal collection/curing operations:
    (i) 0.054 lb of formaldehyde per ton of melt or less,
    (ii) 0.15 lb of phenol per ton of melt or less, and
    (iii) 0.022 lb of methanol per ton of melt or less.
    (3) For combined vertical collection/curing operations:
    (i) 0.46 lb of formaldehyde per ton of melt or less,
    (ii) 0.52 lb of phenol per ton of melt or less, and
    (iii) 0.63 lb of methanol per ton of melt or less.
    (b) You must meet the following operating limits for each combined 
collection/curing operations subcategory:
* * * * *
    4. Section 63.1180 is amended by revising paragraphs (a), (b), and 
(d), and adding paragraph (e) to read as follows:


Sec.  63.1180  When must I meet these standards?

    (a) Existing cupolas and combined collection/curing operations. (1) 
Except as noted in paragraph (a)(2) of this section, the compliance 
date for an owner or operator of an existing plant or source subject to 
the provisions of this subpart is June 2, 2002 or June 3, 2003 if you 
applied for and received a one-year extension under section 
112(i)(b)(3)(B) of the Act.
    (2) The compliance dates for existing plants and sources are:
    (i) [DATE 3 YEARS AFTER PUBLICATION OF THE FINAL RULE IN THE 
FEDERAL REGISTER] for cupolas and combined collection/curing operations 
subject to emission limits in Sec. Sec.  63.1178 and 63.1179 which 
became effective [DATE OF PUBLICATION OF THE FINAL RULE IN THE FEDERAL 
REGISTER].
    (ii) [DATE OF PUBLICATION OF THE FINAL RULE IN THE FEDERAL 
REGISTER] for the provisions related to malfunctions and affirmative 
defense provisions of paragraph (e) of this section and the electronic 
reporting provisions of Sec. Sec.  63.1192(d) and 63.1193(b)(1) and 
(g).
    (b) New and reconstructed cupolas and combined collection/curing 
operations. For affected sources that commenced construction or 
reconstruction after November 25, 2011, you must demonstrate compliance 
with the requirements of this subpart no later than the effective date 
of the rule or upon start-up.
* * * * *
    (d) See Sec.  63.1197 for requirements during startups and 
shutdowns.
    (e) Affirmative defense for exceedance of emissions limits during 
malfunction. In response to an action to enforce the standards set 
forth in this subpart, you may assert an affirmative defense to a claim 
for civil penalties for exceedances of such standards that are caused 
by malfunction, as defined at Sec.  63.2. Appropriate penalties may be 
assessed, however, if you fail to meet your burden of proving all of 
the requirements in the affirmative defense. The affirmative defense 
must not be available for claims for injunctive relief.
    (1) To establish the affirmative defense in any action to enforce 
such a limit, you must timely meet the notification requirements in 
Sec.  63.1191 of this subpart, and must prove by a preponderance of 
evidence that:
    (i) The excess emissions:
    (A) Were caused by a sudden, infrequent, and unavoidable failure of 
air pollution control and monitoring equipment, process equipment, or a 
process to operate in a normal or usual manner; and
    (B) Could not have been prevented through careful planning, proper 
design or better operation and maintenance practices; and
    (C) Did not stem from any activity or event that could have been 
foreseen and avoided, or planned for; and
    (D) Were not part of a recurring pattern indicative of inadequate 
design, operation, or maintenance.
    (ii) Repairs were made as expeditiously as possible when the 
applicable emissions limitations were being exceeded. Off-shift and 
overtime labor were used, to the extent practicable to make these 
repairs; and
    (iii) The frequency, amount and duration of the excess emissions 
(including any bypass) were minimized to the maximum extent practicable 
during periods of such emissions; and
    (iv) If the excess emissions resulted from a bypass of control 
equipment or a process, then the bypass was unavoidable to prevent loss 
of life, personal injury, or severe property damage; and
    (v) All possible steps were taken to minimize the impact of the 
excess emissions on ambient air quality, the environment and human 
health; and
    (vi) All emissions monitoring and control systems were kept in 
operation if at all possible, consistent with safety and good air 
pollution control practices; and
    (vii) All of the actions in response to the excess emissions were 
documented by properly signed, contemporaneous operating logs; and
    (viii) At all times, the affected source was operated in a manner 
consistent with good practices for minimizing emissions; and
    (ix) A written root cause analysis has been prepared, the purpose 
of which is to determine, correct, and eliminate the primary causes of 
the malfunction and the excess emissions resulting from the malfunction 
event at issue. The analysis must also specify, using best monitoring 
methods and engineering judgment, the amount of excess emissions that 
were the result of the malfunction.
    (2) Notification. The owner or operator of the affected source 
experiencing an exceedance of its emissions limit(s) during a 
malfunction, must notify the Administrator by telephone or facsimile 
transmission as soon as possible, but no later than two business days 
after the initial occurrence of the malfunction, s/he

[[Page 72813]]

wishes to be able to use an affirmative defense to civil penalties for 
that malfunction. The owner or operator seeking to assert an 
affirmative defense, must also submit a written report to the 
Administrator within 45 days of the initial occurrence of the 
exceedance of the standards in this subpart. This report must 
demonstrate that the owner/operator met the requirements set forth in 
this paragraph (e) and must include all necessary supporting 
documentation. The owner or operator may seek an extension of this 
deadline for up to 30 additional days by submitting a written request 
to the Administrator before the expiration of the 45 day period. Until 
a request for an extension has been approved by the Administrator, the 
owner or operator is subject to the requirement to submit such report 
within 45 days of the initial occurrence of the exceedance.
    5. Section 63.1182 is amended by revising the section heading, the 
introductory text, and paragraphs (a) and (b) to read as follows:


Sec.  63.1182  How do I comply with the carbonyl sulfide, hydrogen 
fluoride, and hydrogen chloride standards for existing, new, and 
reconstructed cupolas?

    To comply with the COS, HF, and HCL standards, you must meet the 
following:
    (a) Install, calibrate, maintain, and operate a device that 
continuously measures the operating temperature in the firebox of each 
thermal incinerator. For the purposes of this rule, the term 
`incinerator' means `regenerative thermal oxidizer' (RTO).
    (b) Conduct a performance test as specified in Sec.  63.1188 of 
this subpart that shows compliance with the COS, HF, and HCl emissions 
limits while the device for measuring incinerator (regenerative thermal 
oxidizer) operating temperature is installed, operational, and properly 
calibrated. Establish the average operating temperature based on the 
performance test as specified in Sec.  63.1185(a) of this subpart.
* * * * *
    6. Section 63.1183 is amended by revising the section heading, the 
introductory text, and paragraphs (b) and (d) to read as follows:


Sec.  63.1183  How do I comply with the formaldehyde, phenol, and 
methanol standards for existing, new, and reconstructed combined 
collection/curing operations?

    To comply with the formaldehyde, phenol, and methanol standards, 
you must meet all of the following:
* * * * *
    (b) Conduct a performance test as specified in Sec.  63.1188 of 
this subpart while manufacturing the product that requires a binder 
formulation made with the resin containing the highest free-
formaldehyde content specification range. Show compliance with the 
formaldehyde, phenol, and methanol emissions limits while the device 
for measuring the control device operating parameter is installed, 
operational, and properly calibrated. Establish the average operating 
parameter based on the performance test as specified in Sec.  
63.1185(a) of this subpart.
* * * * *
    (d) Following the performance test, monitor and record the free-
formaldehyde content of each resin lot and the formulation of each 
batch of binder used, including the formaldehyde, phenol, and methanol 
content.
* * * * *
    7. Section 63.1188 is amended by revising paragraphs (b), (c), (d), 
(e), and (f) to read as follows:


Sec.  63.1188  What performance test requirements must I meet?

* * * * *
    (b) Conduct a performance test, consisting of three test runs, for 
each cupola and/or combined collection/curing operation subject to this 
subpart at the maximum production rate to demonstrate compliance with 
each of the applicable emissions limits in Sec. Sec.  63.1178 and 
63.1179 of this subpart.
    (c) Following the initial performance or compliance test to be 
conducted within 120 days of the effective date of this rule, you must 
conduct a performance test to demonstrate compliance with each of the 
applicable emissions limits in Sec. Sec.  63.1178 and 63.1179 of this 
subpart at least once every 5 years and as often as the raw material 
ingredients change by more than 10 percent of those processed during 
the previous performance test.
    (d) Measure emissions of PM, COS, HF, and HCl from each existing, 
new, or reconstructed cupola.
    (e) Measure emissions of formaldehyde, phenol, and methanol from 
each existing, new, or reconstructed combined collection/curing 
operation.
    (f) Measure emissions at the outlet of the control device for PM, 
COS, HF, HCl, formaldehyde, phenol, or methanol.
* * * * *
    8. Section 63.1189 is amended by revising paragraph (g) and adding 
paragraph (i) to read as follows:


Sec.  63.1189  What test methods do I use?

* * * * *
    (g) Method 318 in appendix A to this part for the concentration of 
formaldehyde, phenol, methanol, or COS.
* * * * *
    (i) Method 26A or 320 in appendix A to this part for the 
concentration of HF and HCl.
    9. Section 63.1190 is amended by revising paragraph (b) 
introductory text and the ``MW'' entry under ``where:'' and by removing 
paragraph (c).
    The revision reads as follows:


Sec.  63.1190  How do I determine compliance?

* * * * *
    (b) Using the results from the performance tests, you must use the 
following equation to determine compliance with the COS, HF, HCl, 
formaldehyde, phenol, and methanol numerical emissions limits:
* * * * *

MW = Molecular weight of measured pollutant, g/g-mole:

COS = 60.07, HF = 20.01, HCl = 36.46, Formaldehyde = 30.03, Phenol = 
94.11, Methanol = 32.04.
* * * * *
    10. Section 63.1191 is amended by revising the introductory text to 
read as follows:


Sec.  63.1191  What notifications must I submit?

    You must submit written or electronic notifications to the 
Administrator as required by Sec.  63.9(b) through (h) of the general 
provisions in subpart A of this part. Electronic notifications are 
encouraged when possible. These notifications include, but are not 
limited to, the following:
* * * * *
    11. Section 63.1192 is amended by revising paragraph (d) to read as 
follows:


Sec.  63.1192  What recordkeeping requirements must I meet?

* * * * *
    (d) Records must be maintained in a form suitable and readily 
available for expeditious review, according to Sec.  63.10 of the 
General Provisions that are referenced in Table 3 to this subpart. 
Electronic recordkeeping is encouraged.
* * * * *
    12. Section 63.1193 is amended by redesignating paragraphs (b) 
through (f) as paragraphs (c) through (g), and adding a new paragraph 
(b) and by revising the newly redesignated paragraph (g) to read as 
follows:
* * * * *

[[Page 72814]]

    (b)(1) As of January 1, 2012, and within 60 days after the date of 
completing each performance test, as defined in Sec.  63.2, and as 
required in this subpart, you must submit performance test data, except 
opacity data, electronically to the EPA's Central Data Exchange by 
using the ERT (see http://www.epa.gov/ttn/chief/ert/erttool.html/) or 
other compatible electronic spreadsheet. Only data collected using test 
methods compatible with the ERT are subject to this requirement to be 
submitted electronically into the EPA's WebFIRE database.
* * * * *
    (g) All reports required by this subpart not subject to the 
requirements in paragraph (b) of this section must be sent to the 
Administrator at the appropriate address listed in Sec.  63.13. If 
acceptable to both the Administrator and the owner or operator of a 
source, these reports may be submitted on electronic media. The 
Administrator retains the right to require submittal of reports subject 
to paragraph (b) of this section in paper format.
    13. Section 63.1196 is amended by removing the definitions for 
``CO'' and ``formaldehyde'', adding definitions for ``affirmative 
defense'' and ``combined collection/curing operations'', and revising 
the definition for ``incinerator'' to read as follows:


Sec.  63.1196  What definitions should I be aware of?

* * * * *
    Affirmative defense means, in the context of an enforcement 
proceeding, a response or defense put forward by a defendant, regarding 
which the defendant has the burden of proof, and the merits of which 
are independently and objectively evaluated in a judicial or 
administrative proceeding.
    Combined collection/curing operations means the combination of 
fiber collection operations and curing ovens used to make bonded 
products.
    Incinerator means an enclosed air pollution control device that 
uses controlled flame combustion to convert combustible materials to 
noncombustible gases. For the purposes of this rule, the term 
`incinerator' means `regenerative thermal oxidizer' (RTO).
* * * * *
    14. Add Sec.  63.1197 to read as follows:


Sec.  63.1197  Startups and shutdowns.

    (a) The provisions set forth in this subpart apply at all times.
    (b) The owner or operator must not shut down items of equipment 
that are utilized for compliance with this subpart.
    (c) Table 1 to subpart DDD summarizes the emissions limits during 
startups and shutdowns for existing, new, and reconstructed cupolas.

 Table 1 to Subpart DDD--Emissions Limits During Startups and Shutdowns
              for Existing, New, and Reconstructed Cupolas
                      [Pound of pollutant per hour]
------------------------------------------------------------------------
                                              Emission limit (lb/hr)
                                         -------------------------------
                Pollutant                                     New and
                                             Existing      reconstructed
                                              cupolas         cupolas
------------------------------------------------------------------------
PM......................................           1.0             1.0
COS.....................................          32               0.17
HF......................................           0.13            0.13
HCl.....................................           0.092           0.092
------------------------------------------------------------------------

     (d) Table 2 to subpart DDD summarizes the emissions limits during 
startups and shutdowns for existing, new, and reconstructed combined 
collection/curing operations.

 Table 2 to Subpart DDD--Emissions Limits During Startups and Shutdowns
     for Existing, New, and Reconstructed Combined Collection/Curing
                               Operations
                      [Pound of pollutant per hour]
------------------------------------------------------------------------
                                                          Emission limit
              Design                      Pollutant           (lb/hr)
------------------------------------------------------------------------
Vertical..........................  Formaldehyde........          4.5
                                    Phenol..............          5.0
                                    Methanol............          6.0
Horizontal........................  Formaldehyde........          0.52
                                    Phenol..............          1.4
                                    Methanol............          0.21
Drum..............................  Formaldehyde........          0.64
                                    Phenol..............          0.022
                                    Methanol............          0.0074
------------------------------------------------------------------------

    15. Table 1 to subpart DDD of part 63 is redesignated as Table 3 to 
subpart DDD of part 63 and revised to read as follows:

 Table 3 to Subpart DDD of Part 63--Applicability of General Provisions
          (40 CFR Part 63, Subpart A) to Subpart DDD of Part 63
------------------------------------------------------------------------
                                    Applies to
           Reference               subpart DDD            Comment
------------------------------------------------------------------------
63.1..........................  Yes.               .....................
63.2..........................  Yes.               .....................
63.3..........................  Yes.               .....................
63.4..........................  Yes.               .....................
63.5..........................  Yes.               .....................
63.6(a), (b), (c).............  Yes.               .....................
63.6(d).......................  No...............  Section reserved.
63.6(e)(1)(i).................  No...............  See 63.1180 for
                                                    general duty
                                                    requirement.
63.6(e)(1)(ii)................  No.                .....................
63.6(e)(1)(iii)...............  Yes.               .....................
63.6(e)(2)....................  No...............  Section reserved.

[[Page 72815]]

 
63.6(e)(3)....................  No.                .....................
63.6(f)(1)....................  No.                .....................
63.6(g).......................  Yes.               .....................
63.6(h).......................  No...............  No opacity limits in
                                                    rule.
63.6(i).......................  Yes.               .....................
63.6(j).......................  Yes.               .....................
Sec.   63.7(a)-(d)............  Yes.               .....................
Sec.   63.7(e)(1).............  No...............  See 63.1180.
Sec.   63.7(e)(2)-(e)(4)......  Yes.               .....................
63.7(f), (g), (h).............  Yes.               .....................
63.8(a)-(b)...................  Yes.               .....................
63.8(c)(1)(i).................  No...............  See 63.1180 for
                                                    general duty
                                                    requirement.
63.8(c)(1)(ii)................  Yes.               .....................
63.8(c)(1)(iii)...............  No.                .....................
63.8(c)(2)-(d)(2).............  Yes.               .....................
63.8(d)(3)....................  Yes, except for    .....................
                                 last sentence.
63.8(e)-(g)...................  Yes.               .....................
63.9(a), (b), (c), (e), (g),    Yes.               .....................
 (h)(1) through (3), (h)(5)
 and (6), (i) and (j).
63.9(f).......................  No.                .....................
63.9(h)(4)....................  No...............  Reserved.
63.10(a)......................  Yes.               .....................
63.10(b)(1)...................  Yes.               .....................
63.10(b)(2)(i)................  No.                .....................
63.10(b)(2)(ii)...............  No...............  See 63.1193(c) for
                                                    recordkeeping of
                                                    occurrence and
                                                    duration of
                                                    malfunctions and
                                                    recordkeeping of
                                                    actions taken during
                                                    malfunction.
63.10(b)(2)(iii)..............  Yes.               .....................
63.10(b)(2)(iv)-(b)(2)(v).....  No.                .....................
63.10(b)(2)(vi)-(b)(2)(xiv)...  Yes.               .....................
63.(10)(b)(3).................  Yes.               .....................
63.10(c)(1)-(9)...............  Yes.               .....................
63.10(c)(10)-(11).............  No...............  See 63.1192 for
                                                    recordkeeping of
                                                    malfunctions.
63.10(c)(12)-(c)(14)..........  Yes.               .....................
63.10(c)(15)..................  No.                .....................
63.10(d)(1)-(4)...............  Yes.               .....................
63.10(d)(5)...................  No...............  See 63.1193 for
                                                    reporting of
                                                    malfunctions.
63.10(e)-((f).................  Yes.               .....................
63.11.........................  No...............  Flares will not be
                                                    used to comply with
                                                    the emissions
                                                    limits.
63.12 to 63.15................  Yes.               .....................
------------------------------------------------------------------------

Subpart NNN--[Amended]

    16. Section 63.1381 is amended by adding a definition for 
``affirmative defense'' and revising the definition for 
``incinerator''.


Sec.  63.1381  Definitions.

* * * * *
    Affirmative defense means, in the context of an enforcement 
proceeding, a response or defense put forward by a defendant, regarding 
which the defendant has the burden of proof, and the merits of which 
are independently and objectively evaluated in a judicial or 
administrative proceeding.
* * * * *
    Incinerator means an enclosed air pollution control device that 
uses controlled flame combustion to convert combustible materials to 
noncombustible gases. For the purposes of this rule, the term 
`incinerator' means `regenerative thermal oxidizer' (RTO).
* * * * *
    17. Section 63.1382 is amended by revising paragraphs (a) and 
(b)(6) to read as follows:


Sec.  63.1382  Emission standards.

    (a) Emissions limits. (1) Glass-melting furnaces. On and after the 
date the initial performance test is completed or required to be 
completed under Sec.  63.7 of this part, whichever date is earlier,
    (i) The owner or operator of each existing glass-melting furnace 
must not discharge or cause to be discharged into the atmosphere in 
excess of:
    (A) 0.014 pound (lb) of particulate matter (PM) per ton of glass 
pulled;
    (B) 0.0020 lb of hydrogen fluoride (HF) per ton of glass pulled; 
and
    (C) 0.0015 lb of hydrogen chloride (HCl) per ton of glass pulled.
    (D) 0.00006 lb of chromium (Cr) compounds per ton of glass pulled 
(60 lb per million tons glass pulled).
    (ii) The owner or operator of each new or reconstructed glass-
melting furnace must not discharge or cause to be discharged into the 
atmosphere in excess of:
    (A) 0.0018 lb of PM per ton of glass pulled;
    (B) 0.00078 lb of HF per ton of glass pulled; and
    (C) 0.00078 lb of HCl per ton of glass pulled.
    (D) 0.00006 lb of Cr compounds per ton of glass pulled (60 lb per 
million tons glass pulled).
    (2) Rotary spin manufacturing lines. On and after the date the 
initial performance test is completed or required to be completed under 
Sec.  63.7 of this part, whichever date is earlier,
    (i) The owner or operator of each existing rotary spin (RS) 
manufacturing

[[Page 72816]]

line must not discharge or cause to be discharged into the atmosphere 
in excess of:
    (A) 0.17 lb of formaldehyde per ton of glass pulled;
    (B) 0.19 lb of phenol per ton of glass pulled; and
    (C) 0.48 lb of methanol per ton of glass pulled.
    (ii) The owner or operator of each new or reconstructed RS 
manufacturing line must not discharge or cause to be discharged into 
the atmosphere in excess of:
    (A) 0.020 lb of formaldehyde per ton of glass pulled;
    (B) 0.0011 lb of phenol per ton of glass pulled; and
    (C) 0.00067 lb of methanol per ton of glass pulled.
    (3) Flame attenuation manufacturing lines. On and after the date 
the initial performance test is completed or required to be completed 
under Sec.  63.7 of this part, whichever date is earlier,
    (i) The owner or operator of each existing flame attenuation (FA) 
manufacturing line that produces heavy-density wool fiberglass and/or 
pipe insulation must not discharge or cause to be discharged into the 
atmosphere in excess of:
    (A) 5.6 lb of formaldehyde per ton of glass pulled;
    (B) 1.4 lb of phenol per ton of glass pulled; and
    (C) 0.50 lb of methanol per ton of glass pulled.
    (ii) The owner or operator of each new or reconstructed FA 
manufacturing line that produces heavy-density wool fiberglass and/or 
pipe insulation must not discharge or cause to be discharged into the 
atmosphere in excess of:
    (A) 3.3 lb of formaldehyde per ton of glass pulled;
    (B) 0.46 lb of phenol per ton of glass pulled; and
    (C) 0.50 lb of methanol per ton of glass pulled.
    (b) * * *
    (6) The owner or operator must operate each control device used to 
control formaldehyde, phenol, and methanol emissions from forming or 
curing such that any three-hour block average temperature in the 
firebox does not fall below the average established during the 
performance test as specified in Sec.  63.1384.
* * * * *
    18. Section 63.1383 is amended by revising paragraph (f) to read as 
follows:


Sec.  63.1383  Monitoring requirements.

* * * * *
    (f) The owner or operator who uses a control device to control HAP 
emissions from a glass-melting furnace, RS manufacturing line, or FA 
manufacturing line must install, calibrate, maintain, and operate a 
monitoring device that continuously measures an appropriate parameter 
that is correlated to the emission limit performance test.
* * * * *
    19. Section 63.1384 is amended by revising paragraph (c) 
introductory text, variables E, C, and MW, and adding paragraphs (d) 
and (e) to read as follows:


Sec.  63.1384  Performance test requirements.

* * * * *
    (c) To determine compliance with the emission limit for 
formaldehyde, phenol, or methanol for RS manufacturing lines and FA 
manufacturing lines, and for chromium compounds, HF, or HCl for glass-
melting furnaces, use the following equation:
* * * * *

E = Emission rate of formaldehyde, phenol, methanol, chromium 
compounds, HF, or HCl, kg/Mg (lb/ton) of glass pulled;

C = Measured volume fraction of formaldehyde, phenol, methanol, 
chromium compounds, HF, or HCl, ppm;

MW = Molecular weight of formaldehyde, 30.03 g/g-mol; molecular weight 
of phenol, 94.11 g/g-mol; molecular weight of methanol, 32.04 g/g-mol; 
molecular weight of chromium compounds tested in g/g-mol; molecular 
weight of HF, 20.0064 g/g-mol; molecular weight of HCl, 36.4611 g/g-
mol.
    (d) Following the initial performance or compliance test to be 
conducted within 90 days of [EFFECTIVE DATE OF THE RULE] to demonstrate 
compliance with the chromium compounds emissions limit specified in 
Sec.  63.1382(a)(1)(i)(D) or (a)(1)(ii)(D), you must conduct an annual 
performance test for chromium compounds emissions from each glass-
melting furnace (no later than 12 calendar months following the 
previous compliance test).
    (e) Following the initial performance or compliance test to 
demonstrate compliance with the PM, HF, HCl, formaldehyde, phenol, and 
methanol emissions limits specified in Sec.  63.1382, you must conduct 
a performance test to demonstrate compliance with each of the 
applicable PM, HF, HCl, formaldehyde, phenol, and methanol emissions 
limits in Sec.  63.1382 of this subpart at least once every 5 years and 
as often as raw material inputs change by more than 10 percent 
following the previous test.
    20. Section 63.1385 is amended by revising paragraphs (a)(5) and 
(6), and adding paragraphs (a)(11), and (a)(12).


Sec.  63.1385  Test methods and procedures.

    (a) * * *
    (5) Method 5 and Method 202 (40 CFR part 60, appendix A) for the 
concentration of total PM including condensibles. Each run must consist 
of a minimum run time of 2 hours and a minimum sample volume of 60 dry 
standard cubic feet (dscf). The probe and filter holder heating system 
may be set to provide a gas temperature no greater than 177  14[deg]C (350  25[deg]F);
    (6) Method 318 (appendix A of this subpart) for the concentration 
of formaldehyde, phenol, and methanol. Each run must consist of a 
minimum run time of 2 hours;
* * * * *
    (11) Method 0061 (appendix A of this subpart) for the concentration 
of chromium compounds and hexavalent chromium. Each run must consist of 
a minimum run time of 1 hour.
    (12) Method 26A or Method 320 (appendix A of this subpart) for the 
concentration of HF and HCl. Each run must consist of a minimum run 
time of 1 hour.
* * * * *
    21. Section 63.1386 is amended by revising paragraphs (a)(2) 
through (4); revising paragraphs (d)(1)(ii) and (iii); adding 
paragraphs (d)(2)(x), (f) and (g).
    The revisions and addition read as follows:


Sec.  63.1386  Notification, recordkeeping, and reporting requirements.

    (a) * * *
    (2) Notification that a source is subject to the standard, where 
the initial startup is before November 25, 2011.
    (3) Notification that a source is subject to the standard, where 
the source is new or has been reconstructed the initial startup is 
after November 25, 2011, and for which an application for approval of 
construction or reconstruction is not required;
    (4) Notification of intention to construct a new affected source or 
reconstruct an affected source; of the date construction or 
reconstruction commenced; of the anticipated date of startup; of the 
actual date of startup, where the initial startup of a new or 
reconstructed source occurs after November 25, 2011, and for which an 
application for approval or construction or reconstruction is required 
(See Sec.  63.9(b)(4) and (5) of this part);
* * * * *
    (d) * * *
    (1) * * *

[[Page 72817]]

    (ii) The owner or operator may retain records electronically, on a 
computer or labeled computer disks, or on paper; and
* * * * *
    (iii) The owner or operator may report required information on 
paper or on a labeled computer disk using commonly available and EPA-
compatible computer software. Electronic notifications are encouraged 
when possible.
* * * * *
    (2) * * *
    (x) You must report total chromium and hexavalent chromium 
emissions from glass-melting furnaces using Method 0061.
* * * * *
    (f)(1) As of January 1, 2012 and within 60 days after the date of 
completing each performance test, as defined in Sec.  63.2, and as 
required in this subpart, you must submit performance test data, except 
opacity data, electronically to the EPA's Central Data Exchange by 
using the ERT (see http://www.epa.gov/ttn/chief/ert/erttool.html/) or 
other compatible electronic spreadsheet. Only data collected using test 
methods compatible with ERT are subject to this requirement to be 
submitted electronically into the EPA's WebFIRE database.
    (2) All reports required by this subpart not subject to the 
requirements in paragraph (f)(1) of this section must be sent to the 
Administrator at the appropriate address listed in Sec.  63.13. If 
acceptable to both the Administrator and the owner or operator of a 
source, these reports may be submitted on electronic media. The 
Administrator retains the right to require submittal of reports subject 
to paragraph (f)(1) of this section in paper format.
    (g) Affirmative Defense for Exceedance of Emission Limit During 
Malfunction. In response to an action to enforce the standards set 
forth in this subpart, you may assert an affirmative defense to a claim 
for civil penalties for exceedances of such standards that are caused 
by malfunction, as defined at Sec.  63.2. Appropriate penalties may be 
assessed, however, if you fail to meet your burden of proving all of 
the requirements in the affirmative defense. The affirmative defense 
must not be available for claims for injunctive relief.
    (1) To establish the affirmative defense in any action to enforce 
such a limit, you must timely meet the notification requirements in 
Sec.  63.1386 of this subpart, and must prove by a preponderance of 
evidence that:
    (i) The excess emissions:
    (A) Were caused by a sudden, infrequent, and unavoidable failure of 
air pollution control and monitoring equipment, process equipment, or a 
process to operate in a normal or usual manner; and
    (B) Could not have been prevented through careful planning, proper 
design or better operation and maintenance practices; and
    (C) Did not stem from any activity or event that could have been 
foreseen and avoided, or planned for; and
    (D) Were not part of a recurring pattern indicative of inadequate 
design, operation, or maintenance.
    (ii) Repairs were made as expeditiously as possible when the 
applicable emissions limitations were being exceeded. Off-shift and 
overtime labor were used, to the extent practicable to make these 
repairs; and
    (iii) The frequency, amount and duration of the excess emissions 
(including any bypass) were minimized to the maximum extent practicable 
during periods of such emissions; and
    (iv) If the excess emissions resulted from a bypass of control 
equipment or a process, then the bypass was unavoidable to prevent loss 
of life, personal injury, or severe property damage; and
    (v) All possible steps were taken to minimize the impact of the 
excess emissions on ambient air quality, the environment and human 
health; and
    (vi) All emissions monitoring and control systems were kept in 
operation if at all possible, consistent with safety and good air 
pollution control practices; and
    (vii) All of the actions in response to the excess emissions were 
documented by properly signed, contemporaneous operating logs; and
    (viii) At all times, the affected source was operated in a manner 
consistent with good practices for minimizing emissions; and
    (ix) A written root cause analysis has been prepared, the purpose 
of which is to determine, correct, and eliminate the primary causes of 
the malfunction and the excess emissions resulting from the malfunction 
event at issue. The analysis must also specify, using best monitoring 
methods and engineering judgment, the amount of excess emissions that 
were the result of the malfunction.
    (2) Notification. The owner or operator of the affected source 
experiencing an exceedance of its emissions limit(s) during a 
malfunction, must notify the Administrator by telephone or facsimile 
transmission as soon as possible, but no later than two business days 
after the initial occurrence of the malfunction, if he/she wishes to be 
able to use an affirmative defense to civil penalties for that 
malfunction. The owner or operator seeking to assert an affirmative 
defense must also submit a written report to the Administrator within 
45 days of the initial occurrence of the exceedance of the standards in 
this subpart. This report must demonstrate that the owner/operator has 
met the requirements set forth in paragraph (g) of this section and 
must include all necessary supporting documentation. The owner or 
operator may seek an extension of this deadline for up to 30 additional 
days by submitting a written request to the Administrator before the 
expiration of the 45 day period. Until a request for an extension has 
been approved by the Administrator, the owner or operator is subject to 
the requirement to submit such report within 45 days of the initial 
occurrence of the exceedance.
* * * * *
    22. Section 63.1387 is amended by revising paragraphs (a)(1) and 
(2) to read as follows:


Sec.  63.1387  Compliance dates.

    (a) * * *
    (1) Except as noted in paragraph (a)(2) of this section, the 
compliance date for an owner or operator of an existing plant or source 
subject to the provisions of this subpart is [DATE OF PUBLICATION OF 
THE FINAL RULE IN THE FEDERAL REGISTER].
    (2) The compliance dates for existing plants and sources are:
    (i) [DATE 1 YEAR AFTER PUBLICATION OF THE FINAL RULE IN THE FEDERAL 
REGISTER] for glass-melting furnaces, rotary spin manufacturing lines, 
or flame attenuation manufacturing lines subject to emission limits in 
Sec.  63.1382(a) which became effective [DATE OF PUBLICATION OF THE 
FINAL RULE IN THE FEDERAL REGISTER].
    (ii) [DATE OF PUBLICATION OF THE FINAL RULE IN THE FEDERAL 
REGISTER] for the provisions related to malfunctions and affirmative 
defense provisions of Sec.  63.1386(g) and the electronic reporting 
provisions of Sec.  63.1386(d) and (f).
* * * * *
    23. Section 63.1388 is revised to read as follows:


Sec.  63.1388  Startups and shutdowns.

    (a) The provisions set forth in this subpart apply at all times.
    (b) The owner or operator must not shut down items of equipment 
that are required or utilized for compliance with the provisions of 
this subpart during times when emissions are being routed to such items 
of equipment, if the shutdown would contravene requirements of this 
subpart applicable

[[Page 72818]]

to such items of equipment. This paragraph does not apply if the owner 
or operator must shut down the equipment to avoid damage due to a 
contemporaneous startup or shutdown, of the affected source or a 
portion thereof.
    (c) Table 1 to subpart NNN summarizes the emissions limits during 
startups and shutdowns of glass-melting furnaces.

 Table 1 to Subpart NNN--emissions Limits During Startups and Shutdowns
                    of Glass-Melting Furnaces (lb/hr)
------------------------------------------------------------------------
                                                              New and
                Pollutant                    Existing      reconstructed
                                             furnaces        furnaces
------------------------------------------------------------------------
PM......................................          0.25            0.033
Chromium Compounds......................          0.0019          0.0019
HF......................................          0.036           0.014
HCl.....................................          0.026           0.014
------------------------------------------------------------------------

    (d) Table 1 to subpart NNN summarizes the emissions limits during 
startups and shutdowns of rotary spin [RS] manufacturing lines.

 Table 2 to Subpart NNN--Emissions Limits During Startups and Shutdowns
             of Rotary Spin (RS) Manufacturing Lines (lb/hr)
------------------------------------------------------------------------
                                                              New and
                Pollutant                   Existing RS    reconstructed
                                               lines         RS lines
------------------------------------------------------------------------
Formaldehyde............................             3.1           0.36
Phenol..................................             3.4           0.019
Methanol................................             8.8           0.012
------------------------------------------------------------------------

     (e) Table 3 to subpart NNN summarizes the emissions limits during 
startups and shutdowns of flame attenuation (FA) manufacturing lines.

 Table 3 to Subpart NNN--Emissions Limits During Startups and Shutdowns
          of Flame Attenuation (FA) Manufacturing Lines (lb/hr)
------------------------------------------------------------------------
                                                              New and
                Pollutant                   Existing FA    reconstructed
                                               lines         FA lines
------------------------------------------------------------------------
Formaldehyde............................             100              60
Phenol..................................              25               8
Methanol................................               9               9
------------------------------------------------------------------------

    24. Table 1 to Subpart NNN of Part 63 is redesignated as Table 4 to 
Subpart NNN of Part 63 and revised to read as follows:

 Table 4 to Subpart NNN of Part 63--General Provisions Applicability to
                               Subpart NNN
------------------------------------------------------------------------
                                    Applies to
           Reference               subpart NNN            Comment
------------------------------------------------------------------------
63.1..........................  Yes.               .....................
63.2..........................  Yes.               .....................
63.3..........................  Yes.               .....................
63.4..........................  Yes.               .....................
63.5..........................  Yes.               .....................
63.6(a), (b), (c).............  Yes.               .....................
63.6(d).......................  No...............  Section reserved.
63.6(e)(1)(i).................  No...............  See 63.1382(b) for
                                                    general duty
                                                    requirement.
63.6(e)(1)(ii)................  No.                .....................
63.6(e)(1)(iii)...............  Yes.               .....................
63.6(e)(2)....................  No...............  Section reserved.
63.6(e)(3)....................  No.                .....................
63.6(f)(1)....................  No.                .....................
63.6(g).......................  Yes.               .....................
63.6(h).......................  No...............  No opacity limits in
                                                    rule.
63.6(i).......................  Yes.               .....................
63.6(j).......................  Yes.               .....................

[[Page 72819]]

 
Sec.   63.7(a)-(d)............  Yes.               .....................
Sec.   63.7(e)(1).............  No...............  See 63.1382(b).
Sec.   63.7(e)(2)-(e)(4)......  Yes.               .....................
63.7(f), (g), (h).............  Yes.               .....................
63.8(a)-(b)...................  Yes.               .....................
63.8(c)(1)(i).................  No...............  See 63.1382(b) for
                                                    general duty
                                                    requirement.
63.8(c)(1)(ii)................  Yes.               .....................
63.8(c)(1)(iii)...............  No.                .....................
63.8(c)(2)-(d)(2).............  Yes.               .....................
63.8(d)(3)....................  Yes, except for    .....................
                                 last sentence.
63.8(e)-(g)...................  Yes.               .....................
63.9(a), (b), (c), (e), (g),    Yes.               .....................
 (h)(1) through (3), (h)(5)
 and (6), (i) and (j).
63.9(f).......................  No.                .....................
63.9(h)(4)....................  No...............  Reserved.
63.10 (a).....................  Yes.               .....................
63.10 (b)(1)..................  Yes.               .....................
63.10(b)(2)(i)................  No.                .....................
63.10(b)(2)(ii)...............  No...............  See 63.1386 for
                                                    recordkeeping of
                                                    occurrence and
                                                    duration of
                                                    malfunctions and
                                                    recordkeeping of
                                                    actions taken during
                                                    malfunction.
63.10(b)(2)(iii)..............  Yes.               .....................
63.10(b)(2)(iv)-(b)(2)(v).....  No.                .....................
63.10(b)(2)(vi)-(b)(2)(xiv)...  Yes.               .....................
63.(10)(b)(3).................  Yes.               .....................
63.10(c)(1)-(9)...............  Yes.               .....................
63.10(c)(10)-(11).............  No...............  See 63.1386 for
                                                    recordkeeping of
                                                    malfunctions.
63.10(c)(12)-(c)(14)..........  Yes.               .....................
63.10(c)(15)..................  No.                .....................
63.10(d)(1)-(4)...............  Yes.               .....................
63.10(d)(5)...................  No...............  See 63.1386(c)(2) for
                                                    reporting of
                                                    malfunctions.
63.10(e)-((f).................  Yes.               .....................
63.11.........................  No...............  Flares will not be
                                                    used to comply with
                                                    the emissions
                                                    limits.
63.12 to 63.15................  Yes.               .....................
------------------------------------------------------------------------

[FR Doc. 2011-29454 Filed 11-23-11; 8:45 am]
BILLING CODE 6560-50-P