[Federal Register Volume 85, Number 114 (Friday, June 12, 2020)]
[Proposed Rules]
[Pages 35874-35895]
[FR Doc No: 2020-11990]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 82

[EPA-HQ-OAR-2019-0698; FRL-10009-66-OAR]
RIN 2060-AU81

Protection of Stratospheric Ozone: Listing of Substitutes Under
the Significant New Alternatives Policy Program

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of proposed rulemaking.

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SUMMARY: Pursuant to the U.S. Environmental Protection Agency's (EPA)
Significant New Alternatives Policy program, this action proposes to
list certain substances in the refrigeration and air conditioning
sector and the foam blowing sector. For the retail food refrigeration--
medium-temperature stand-alone units (new) end-use, EPA is proposing to
list substitutes as acceptable subject to narrowed use limits. For the
residential and light commercial air conditioning and heat pumps (new)
end-use, EPA is proposing to list substitutes as acceptable subject to
use conditions. For the foam blowing sector, extruded polystyrene:
Boardstock and billet end-use, EPA is proposing to list substitutes as
acceptable. This action also proposes to remove an acceptable subject
to use conditions listing for the fire suppression sector because EPA
more recently listed the substitute as acceptable with no use
restrictions.

DATES: Comments must be received on or before July 27, 2020. Any party
requesting a public hearing must notify the contact listed below under
FOR FURTHER INFORMATION CONTACT by 5 p.m. Eastern Daylight Time on June
17, 2020. If a virtual hearing is held, it will take place on or before
June 29, 2020 and further information will be provided on EPA's
Stratospheric Ozone website at www.epa.gov/ozone/snap.

ADDRESSES: You may send comments, identified by docket identification
(ID) number EPA-HQ-OAR-2019-0698, to the Federal eRulemaking Portal:
http://www.regulations.gov. Follow the online instructions for
submitting comments. Once submitted, comments cannot be edited or
withdrawn. EPA may publish any comment received to its public docket.
Do not submit electronically any information you consider to be
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Multimedia submissions (audio,
video, etc.) must be accompanied by a written comment. The written
comment is considered the official comment and should include
discussion of all points you wish to make. EPA will generally not
consider comments or comment contents located outside of the primary
submission (i.e., on the web, cloud, or other file sharing system). For
additional submission methods, EPA's full public comment policy,
information about CBI or multimedia submissions, and general guidance
on making effective comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets. Out of an abundance of caution for members of
the public and our staff, the EPA Docket Center and Reading Room was
closed to public visitors on March 31, 2020, to reduce the risk of
transmitting COVID-19. Our Docket Center staff will continue to provide
remote customer service via email, phone, and webform. We encourage the
public to submit comments via https://www.regulations.gov or email, as
there is a temporary suspension of mail delivery to EPA, and no hand
deliveries are currently accepted. For further information on EPA
Docket Center services and the current status, please visit us online
at https://www.epa.gov/dockets.

FOR FURTHER INFORMATION CONTACT: Christina Thompson, Stratospheric
Protection Division, Office of Atmospheric Programs (Mail Code 6205T),
Environmental Protection Agency, 1200 Pennsylvania Ave. NW, Washington,
DC 20460; telephone number:<PHONE_NUMBER>; email address:
<EMAIL_ADDRESS>Notices and rulemakings under EPA's
Significant New Alternatives Policy program are available on EPA's
Stratospheric Ozone website at https://www.epa.gov/snap/snap-regulations.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. General Information
    A. Executive Summary and Background
    B. Does this action apply to me?
    C. What acronyms and abbreviations are used in the preamble?
II. What is EPA proposing in this action?
    A. Retail Food Refrigeration--Proposed Listing of R-448A, R-449A
and R-449B as Acceptable, Subject to Narrowed Use Limits, for Retail
Food Refrigeration--Medium-Temperature Stand-Alone Units (New)
    1. Background on Retail Food Refrigeration--Medium-Temperature
Stand-Alone Units
    2. What are R-448A, R-449A and R-449B and how do they compare to
other refrigerants in the same end-use?
    3. Summary of AHRI Petition
    4. What is EPA proposing for R-448A, R-449A and R-449B?
    B. Residential and Light Commercial Air Conditioning and Heat
Pumps--Proposed Listing of R-452B, R-454A, R-454B, R-454C, and R-
457A as Acceptable, Subject to Use Conditions, for Use in
Residential and Light Commercial Air Conditioning and Heat Pumps
End-Use for New Equipment; and R-32 as Acceptable, Subject to Use
Conditions, for Use in Residential and Light Commercial Air
Conditioning and Heat Pumps--Equipment Other Than Self-Contained
Room Air Conditioners, for New Equipment
    1. Background on Residential and Light Commercial Air
Conditioning and Heat Pumps
    2. What are the ASHRAE classifications for refrigerant
flammability?
    3. What are R-32, R-452B, R-454A, R-454B, R-454C, and R-457A and
how do they compare to other refrigerants in the same end-use?
    4. Why is EPA proposing these specific use conditions?

    5. What additional information is EPA including in these
listings?
    6. On what aspects is EPA requesting additional comment?
    C. Extruded Polystyrene: Boardstock and Billet--Proposed Listing
of Blends of 40 to 52 Percent HFC-134a by Weight and the Remainder
HFO-1234ze(E); Blends of 40 to 52 Percent HFC-134a With 40 to 60
Percent HFO-1234ze(E) and 10 to 20 Percent Each Water and
CO2 by Weight; and Blends With Maximum of 51 Percent HFC-
134a, 17 to 41 Percent HFC-152a, up to 20 Percent CO2 and
One to 13 Percent Water
    1. Background on XPS
    2. What are blends of 40 to 52 percent HFC-134a and the
remainder HFO-1234ze(E); blends of 40 to 52 percent HFC-134a with 40
to 60 percent HFO-1234ze(E) and 10 to 20 percent each water and
carbon dioxide; and blends with maximum of 51 percent HFC-134a, 17
to 41 percent HFC-152a, up to 20 percent CO2 and one to
13 percent water, and how do they compare to other foam blowing
agents in the same end-use?
    3. What is EPA proposing for HFC-134a blends in XPS?
    D. Total Flooding: Proposed Removal of Powdered Aerosol E From
the List of Substitutes Acceptable Subject to Use Conditions
III. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Executive Order 13771: Reducing Regulations and Controlling
Regulatory Costs
    C. Paperwork Reduction Act
    D. Regulatory Flexibility Act
    E. Unfunded Mandates Reform Act
    F. Executive Order 13132: Federalism
    G. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
    H. Executive Order 13045: Protection of Children From
Environmental Health and Safety Risks
    I. Executive Order 13211: Actions That Significantly Affect
Energy Supply, Distribution, or Use
    J. National Technology Transfer and Advancement Act
    K. Executive Order 12898: Federal Actions To Address
Environmental Justice in Minority Populations and Low-Income
Population
    IV. References

I. General Information

A. Executive Summary and Background

    This action proposes to list new alternatives for the refrigeration
and air conditioning sector and for the foam blowing sector and to
change an existing listing for the fire suppression sector.
Specifically, EPA is proposing to:
     List R-448A, R-449A and R-449B as acceptable, subject to
narrowed use limits, for use in retail food refrigeration--medium-
temperature stand-alone units for new equipment;
     List R-452B, R-454A, R-454B, R-454C and R-457A as
acceptable, subject to use conditions, for use in residential and light
commercial air conditioning (AC) and heat pumps for new equipment and
R-32 as acceptable, subject to use conditions, for use in residential
and light commercial AC and heat pumps--equipment other than self-
contained room air conditioners, for new equipment;
     List blends of 40 to 52 percent hydrofluorocarbon (HFC)-
134a and the remainder hydrofluoroolefin (HFO)-1234ze(E); blends of 40
to 52 percent HFC-134a with 40 to 60 percent HFO-1234ze(E) and 10 to 20
percent each water and carbon dioxide (CO2); and blends with
maximum of 51 percent HFC-134a, 17 to 41 percent HFC-152a, up to 20
percent CO2 and one to 13 percent water as acceptable for
use in extruded polystyrene: Boardstock and billet (XPS); and
     Remove Powdered Aerosol E from the list of fire
suppression substitutes acceptable subject to use conditions in total
flooding applications.
    EPA is proposing these listings after its evaluation of human
health and environmental information on various substitutes submitted
to the Significant New Alternatives Policy (SNAP) program. This action
provides additional flexibility for industry by providing new options
in specific uses and situations.
    In this proposed rule, EPA refers to listings made in a final rule
issued July 20, 2015, at 80 FR 42870 (``2015 Rule''). The 2015 Rule,
among other things, changed the listings for certain HFCs and blends
from acceptable to unacceptable in various end-uses in the aerosols,
refrigeration and air conditioning, and foam blowing sectors. After a
challenge to the 2015 Rule, the United States Court of Appeals for the
District of Columbia Circuit (``the court'') issued a partial vacatur
of the 2015 Rule ``to the extent it requires manufacturers to replace
HFCs with a substitute substance'' \1\ and remanded the rule to the
Agency for further proceedings.\2\ The court also upheld EPA's listing
changes as being reasonable and not ``arbitrary and capricious.'' \3\
This proposed rule is not EPA's response to the court's decision. EPA
is developing a future proposed rule to respond to the court's
decision.
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    \1\ Mexichem Fluor, Inc. v. EPA, 866 F.3d 451, 462 (D.C. Cir.
2017).
    \2\ Later, the court issued a similar decision on portions of a
similar final rule issued December 1, 2016 at 81 FR 86778 (``2016
Rule''). See Mexichem Fluor, Inc. v. EPA, Judgment, Case No. 17-1024
(D.C. Cir., April 5, 2019), 760 Fed. Appx. 6 (Mem). That rule is not
relevant for this action.
    \3\ Mexichem Fluor, 866 F.3d at 462-63.
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SNAP Program Background
    The SNAP program implements section 612 of the Clean Air Act (CAA).
Several major provisions of section 612 are:
1. Rulemaking
    Section 612(c) requires EPA to promulgate rules making it unlawful
to replace any class I (chlorofluorocarbon (CFC), halon, carbon
tetrachloride, methyl chloroform, methyl bromide,
hydrobromofluorocarbon, and chlorobromomethane) or class II
(hydrochlorofluorocarbon (HCFC)) ozone-depleting substances (ODS) with
any substitute that the Administrator determines may present adverse
effects to human health or the environment where the Administrator has
identified an alternative that (1) reduces the overall risk to human
health and the environment and (2) is currently or potentially
available.
2. Listing of Unacceptable/Acceptable Substitutes
    Section 612(c) requires EPA to publish a list of the substitutes
that it finds to be unacceptable for specific uses and to publish a
corresponding list of acceptable substitutes for specific uses.
3. Petition Process
    Section 612(d) grants the right to any person to petition EPA to
add a substance to, or delete a substance from, the lists published in
accordance with section 612(c).
4. 90-Day Notification
    Section 612(e) directs EPA to require any person who produces a
chemical substitute for a class I substance to notify the Agency not
less than 90 days before a new or existing chemical is introduced into
interstate commerce for significant new use as a substitute for a class
I substance. The producer must also provide the Agency with the
producer's unpublished health and safety studies on such substitutes.
    The regulations for the SNAP program are promulgated at 40 CFR part
82, subpart G, and the Agency's process for reviewing SNAP submissions
is described in regulations at 40 CFR 82.180. Under these rules, the
Agency has identified five types of listing decisions: Acceptable;
acceptable subject to use conditions; acceptable subject to narrowed
use limits; unacceptable; and pending (40 CFR 82.180(b)). Use
conditions and narrowed use limits are both considered

``use restrictions,'' as described below. Substitutes that are deemed
acceptable with no use restrictions (no use conditions or narrowed use
limits) can be used for all applications within the relevant end-uses
in the sector. After reviewing a substitute, the Agency may determine
that a substitute is acceptable only if certain conditions in the way
that the substitute is used are met to minimize risks to human health
and the environment. EPA describes such substitutes as ``acceptable
subject to use conditions.'' (40 CFR 82.180(b)(2)). For some
substitutes, the Agency may permit a narrowed range of use within an
end-use or sector. For example, the Agency may limit the use of a
substitute to certain end-uses or specific applications within an
industry sector. EPA describes these substitutes as ``acceptable
subject to narrowed use limits.'' Under the narrowed use limit, users
intending to adopt these substitutes ``must ascertain that other
alternatives are not technically feasible.'' (40 CFR 82.180(b)(3)).
    In making decisions regarding whether a substitute is acceptable or
unacceptable, and whether substitutes present risks that are lower than
or comparable to risks from other substitutes that are currently or
potentially available in the end-uses under consideration, EPA examines
the criteria in 40 CFR 82.180(a)(7): (i) Atmospheric effects and
related health and environmental impacts; (ii) general population risks
from ambient exposure to compounds with direct toxicity and to
increased ground-level ozone; (iii) ecosystem risks; (iv) occupational
risks; (v) consumer risks; (vi) flammability; and (vii) cost and
availability of the substitute.
    For additional information on the SNAP program, visit the SNAP
portion of EPA's Ozone Layer Protection website at www.epa.gov/snap.
Copies of the full lists of acceptable substitutes for ODS in all
industrial sectors are available at www.epa.gov/snap/substitutes-sector. For more information on the Agency's process for administering
the SNAP program or criteria for evaluation of substitutes, refer to
the initial SNAP rulemaking published March 18, 1994 (59 FR 13044),
codified at 40 CFR part 82, subpart G. SNAP decisions and the
appropriate Federal Register citations are found at: www.epa.gov/snap/snap-regulations. Substitutes listed as unacceptable; acceptable,
subject to narrowed use limits; or acceptable, subject to use
conditions, are also listed in the appendices to 40 CFR part 82,
subpart G.

B. Does this action apply to me?

    The following list identifies regulated entities that may be
affected by this proposed rule and their respective North American
Industrial Classification System (NAICS) codes:

 All Other Basic Organic Chemical Manufacturing (NAICS 325199)
 Polystyrene Foam Product Manufacturing (NAICS 326140)
 Urethane and Other Foam Product (except Polystyrene)
Manufacturing (NAICS 326150)
 Air Conditioning and Warm Air Heating Equipment and Commercial
and Industrial Refrigeration Equipment Manufacturing (NAICS 333415)
 Refrigeration Equipment and Supplies Merchant Wholesalers
(NAICS 423740)
 Supermarkets and Other Grocery (except Convenience) Stores
(NAICS 44511 & 445110)
 Convenience Stores (NAICS 445120)
 Limited-Service Restaurants (NAICS 722513)
 Cafeterias, Grill Buffets, and Buffets (NAICS 722514)
 Snack and Nonalcoholic Beverage Bars (NAICS 722515)
 Fire Protection (NAICS 922160)

C. What acronyms and abbreviations are used in the preamble?

    Below is a list of acronyms and abbreviations used in the preamble
of this document:

AC--Air Conditioning
ADA--Americans with Disabilities Act
AEL--Acceptable Exposure Limit
AHRI--Air-Conditioning, Heating, and Refrigeration Institute
ANSI--American National Standards Institute
ASHRAE--American Society of Heating, Refrigerating and Air-Conditioning
Engineers
ASTM--American Society for Testing and Materials
CAA--Clean Air Act
CAS Reg. No.--Chemical Abstracts Service Registry Identification Number
CBI--Confidential Business Information
CCAC--Climate and Clean Air Coalition
CFC--Chlorofluorocarbon
CFR--Code of Federal Regulations
CO2--Carbon Dioxide
DOE--United States Department of Energy
EPA--United States Environmental Protection Agency
FR--Federal Register
GSHP--Ground-Source Heat Pump
GWP--Global Warming Potential
HCFC--Hydrochlorofluorocarbon
HFC--Hydrofluorocarbon
HFO--Hydrofluoroolefin
HP--Heat Pump
ICF--ICF International, Inc.
IPCC--Intergovernmental Panel on Climate Change
LFL--Lower Flammability Limit
MBtu--Million British thermal units
NAAQS--National Ambient Air Quality Standards
NAICS--North American Industrial Classification System
NFPA--National Fire Protection Association
NIOSH--National Institute for Occupational Safety and Health
NPRM--Notice of Proposed Rulemaking
ODP--Ozone Depletion Potential
OMB--United States Office of Management and Budget
OSHA--United States Occupational Safety and Health Administration
PEL--Permissible Exposure Limit
ppm--Parts Per Million
PRA--Paperwork Reduction Act
PTAC--Packaged Terminal Air Conditioner
PTHP--Packaged Terminal Heat Pump
RFA--Regulatory Flexibility Act
SDS--Safety Data Sheet
SIP--State Implementation Plan
SNAP--Significant New Alternatives Policy
STEL--Short-term Exposure Limit
TSCA--Toxic Substances Control Act
TWA--Time Weighted Average
UL--Underwriters Laboratories Inc
UMRA--Unfunded Mandates Reform Act
VOC--Volatile Organic Compounds
VRF--Variable Refrigerant Flow
WEEL--Workplace Environmental Exposure Limit
WSHP--Water-Source Heat Pump
XPS--Extruded Polystyrene: Boardstock and Billet

II. What is EPA proposing in this action?

A. Retail Food Refrigeration--Proposed Listing of R-448A, R-449A and R-
449B as Acceptable, Subject to Narrowed Use Limits, for Retail Food
Refrigeration--Medium-Temperature Stand-Alone Units (new)

    EPA is proposing to list R-448A, R-449A, and R-449B as acceptable,
subject to narrowed use limits, in new equipment only for new medium-
temperature stand-alone units in retail food refrigeration (hereafter,
``new medium-temperature stand-alone units'').\4\
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    \4\ EPA previously divided the retail food refrigeration end-use
into separate categories, including stand-alone equipment (76 FR
78832, December 20, 2011). The Agency further subdivided stand-alone
equipment to distinguish between medium-temperature equipment, which
maintains products above 32 [deg]F (0 [deg]C), and low-temperature
equipment, which maintains products at or below 32[ordm]F (0 [deg]C)
(80 FR 42870, July 20, 2015).

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    Under the narrowed use limit, users \5\ intending to adopt these
refrigerants ``must ascertain that other alternatives are not
technically feasible.'' (40 CFR 82.180(b)(3)). In addition, the end
users ``must document the results of their evaluation and retain the
results on file for the purpose of demonstrating compliance. This
documentation shall include descriptions of substitutes examined and
rejected, processes or products in which the substitute is needed,
reason for rejection of other alternatives, e.g., performance,
technical or safety standards, and the anticipated date other
substitutes will be available and projected time for switching to other
available substitutes.'' (40 CFR 82.180(b)(3)).
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    \5\ Note that the definition of ``use'' includes ``but [is] not
limited to use in a manufacturing process or product, in consumption
by the end-user, or in intermediate uses, such as formulation or
packaging for other subsequent uses''; hence, this definition
includes the manufacture of a product pre-charged with or intended
for a particular refrigerant. (40 CFR 82.172).
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1. Background on Retail Food Refrigeration--Medium-Temperature Stand-
Alone Units
    Retail food refrigeration is characterized by storing and
displaying, generally for sale, food and beverages at different
temperatures for different products (e.g., chilled and frozen food).
Stand-alone units in retail food refrigeration (hereafter, ``stand-
alone units'') consist of refrigerators, freezers, and reach-in coolers
(either open or with doors) where all refrigeration components are
integrated and, for the smallest types, the refrigeration circuit is
entirely brazed or welded. These systems are charged with refrigerant
at the factory and typically require only an electricity supply to
begin operation.
    For purposes of the SNAP program, medium-temperature stand-alone
units maintain a temperature above 32 [deg]F (0 [deg]C). Most are
typically designed to maintain products at temperatures roughly between
32 [deg]F (0 [deg]C) and 41 [deg]F (5 [deg]C). EPA treats this as a
separate end-use category from low-temperature stand-alone units
designed to maintain products at temperatures roughly between -40
[deg]F (-40 [deg]C) and 32 [deg]F (0 [deg]C) (i.e., freezers). In
addition, the Agency considers equipment designed to make or process
cold food and beverages that are dispensed via a nozzle, including
soft-serve ice cream machines, ``slushy'' iced beverage dispensers, and
soft-drink dispensers, to be a separate end-use category from stand-
alone units (refrigerated food processing and dispensing equipment).
EPA has listed different substitutes as acceptable in these end-use
categories based on the Agency's understanding of the availability of
substitutes able to meet the technical and regulatory requirements for
each equipment type and temperature range. For example, EPA listed R-
448A, R-449A and R-449B as acceptable in low-temperature stand-alone
units and in refrigerated food processing and dispensing equipment (80
FR 42053, July 16, 2015; 81 FR 70029, October 11, 2016). Whereas EPA
listed R-290 (propane) as acceptable subject to use conditions in
stand-alone units, both medium-temperature and low-temperature (76 FR
78832, December 20, 2011), the Agency has not listed it for
refrigerated food processing and dispensing equipment. Acceptable
substitutes for medium-temperature stand-alone units include ammonia
vapor compression with secondary loop, R-744 (carbon dioxide or
CO2), R-290, R-441A, R-450A, R-513A, and R-600a (isobutane),
among others.
    In the 2015 Rule, EPA changed the listing of 31 refrigerants \6\
from acceptable to unacceptable for medium temperature stand-alone
units. At that time, EPA indicated that it believed that other
alternatives that posed lower risk were available for this end use. As
part of a petition from the Air-Conditioning, Heating, and
Refrigeration Institute (AHRI),\7\ described in section 3 below, EPA
received information indicating that manufacturers were unable to
design certain types of medium-temperature stand-alone equipment with
the available acceptable alternatives. AHRI explained that due to the
thermodynamic properties of the available alternatives, equipment would
need to be redesigned using larger components. Because these components
are located at the bottom of the unit, the larger size would lead to
designs where the refrigerated product would be placed too high to
comply with countertop height requirements of the Americans with
Disabilities Act (ADA), or would be too wide such that it protruded
into aisles and likewise conflicted with ADA requirements.
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    \6\ Specifically, FOR12A, FOR12B, HFC-134a, HFC-227ea, KDD6,
R125/290/134a/600a (55.0/1.0/42.5/1.5), R-404A, R-407A, R-407B, R-
407C, R-407F, R-410A, R-410B, R-417A, R-421A, R-421B, R-422A, R-
422B, R-422C, R-422D, R-424A, R-426A, R-428A, R-434A, R-437A, R-
438A, R-507A, RS-24 (2002 formulation), RS-44 (2003 formulation),
SP34E, and THR-03.
    \7\ AHRI, 2017. Petition Requesting EPA SNAP Approval of R-448A/
449A/449B for Medium Temperature, Stand-Alone Retail Food
Refrigeration Equipment. Submitted March 20, 2017.
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2. What are R-448A, R-449A and R-449B and how do they compare to other
refrigerants in the same end-use?
    R-448A, marketed under the trade name Solstice[supreg] N-40, is a
weighted blend of 26 percent HFC-32, which is also known as
difluoromethane (Chemical Abstracts Service Registry Number [CAS Reg.
No.] 75-10-5); 26 percent HFC-125, which is also known as 1,1,1,2,2-
pentafluoroethane (CAS Reg. No. 354-33-6); 21 percent HFC-134a, which
is also known as 1,1,1,2-tetrafluoroethane (CAS Reg. No. 811-97-2); 20
percent HFO-1234yf, which is also known as 2,3,3,3-tetrafluoroprop-1-
ene (CAS Reg. No. 754-12-1); and seven percent HFO-1234ze(E), which is
also known as trans-1,3,3,3-tetrafluoroprop-1-ene (CAS Reg. No. 29118-
24-9). R-449A, marketed under the trade name Opteon[supreg] XP 40, is a
weighted blend of 24.3 percent HFC-32, 24.7 percent HFC-125, 25.7
percent HFC-134a, and 25.3 percent HFO-1234yf. R-449B, marketed under
the trade name Forane[supreg] 449B, is a weighted blend of 25.2 percent
HFC-32, 24.3 percent HFC-125, 27.3 percent HFC-134a, and 23.2 percent
HFO-1234yf.
    EPA previously listed R-448A, R-449A, and R-449B as acceptable
refrigerants in a number of other refrigeration and air conditioning
end-uses, including other retail food refrigeration end-use categories
(e.g., 80 FR 42053, July 16, 2015; 81 FR 70029, October 11, 2016; 82 FR
33809, July 21, 2017; 83 FR 50026, October 4, 2018; 84 FR 64765,
November 25, 2019).
    Redacted submissions and supporting documentation for R-448A, R-
449A, and R-449B are provided in the docket for this proposed rule
(EPA-HQ-OAR-2019-0698) at https://www.regulations.gov. EPA performed an
assessment to examine the health and environmental risks of each of
these substitutes. These assessments are available in the docket for
this proposed rule.8 9 10
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    \8\ ICF, 2020a. Risk Screen on Substitutes in Retail Food
Refrigeration (Medium-temperature Stand-alone Units) (New
Equipment); Substitute: R-448A.
    \9\ ICF, 2020b. Risk Screen on Substitutes in Retail Food
Refrigeration (Medium-temperature Stand-alone Units) (New
Equipment); Substitute: R-449A.
    \10\ ICF, 2020c. Risk Screen on Substitutes in Retail Food
Refrigeration (Medium-temperature Stand-alone Units) (New
Equipment); Substitute: R-449B.
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    Environmental information: R-448A, R-449A, and R-449B have an ozone
depletion potential (ODP) of zero.\11\

Their components, HFC-32, HFC-125, HFC-134a, HFO-1234yf, and in the
case of R-448A, HFO-1234ze(E), have global warming potentials (GWPs) of
675; 3,500; 1,430; \12\ one to four; 13 14 and one to six;
\15\ respectively. HFC-32 (CAS Reg. No. 75-10-5), HFC-125 (CAS Reg. No.
354-33-6), HFC-134a (CAS Reg. No. 811-97-2), HFO-1234yf (CAS Reg. No.
754-12-1) and HFO-1234ze(E) (CAS Reg. No. 29118-24-9)--the components
of R-448A, R-449A, and R-449B--are excluded from the definition of
volatile organic compounds (VOC) under CAA regulations (see 40 CFR
51.100(s)) addressing the development of state implementation plans
(SIPs) to attain and maintain the national ambient air quality
standards (NAAQS). Knowingly venting or otherwise knowingly releasing
or disposing of these refrigerant blends in the course of maintaining,
servicing, repairing or disposing of an appliance or industrial process
refrigeration is prohibited as provided in section 608(c)(2) of the CAA
and EPA's regulations at 40 CFR 82.154(a)(1).
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    \11\ If a compound contains no chlorine, bromine, or iodine, or
if it is a solid under conditions of use, its ODP is generally
considered to be zero. Unless otherwise stated, all non-zero ODPs in
this document are from EPA's regulations at appendix A to subpart A
of 40 CFR part 82.
    \12\ Unless otherwise specified, GWP values are from IPCC (2007)
Climate Change 2007: The Physical Science Basis. Contribution of
Working Group I to the Fourth Assessment Report of the
Intergovernmental Panel on Climate Change. S. Solomon, D. Qin, M.
Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller
(eds.). Cambridge University Press. Cambridge, United Kingdom 996
pp.
    \13\ Nielsen et al., 2007. Nielsen, O.J., Javadi, M.S., Sulbaek
Andersen, M.P., Hurley, M.D., Wallington, T.J., Singh, R. 2007.
Atmospheric chemistry of CF3CF=CH2: Kinetics
and mechanisms of gas-phase reactions with Cl atoms, OH radicals,
and O3. Chemical Physics Letters 439, 18-22. Available
online at http://www.cogci.dk/network/OJN_174_CF3CF=CH2.pdf.
    \14\ Hodnebrog [Oslash]. et al., 2013. Hodnebrog [Oslash].,
Etminan, M., Fuglestvedt, J.S., Marston, G., Myhre, G., Nielsen,
C.J., Shine, K.P., Wallington, T.J.: Global Warming Potentials and
Radiative Efficiencies of Halocarbons and Related Compounds: A
Comprehensive Review, Reviews of Geophysics, 51, 300-378,
doi:10.1002/rog.20013, 2013.
    \15\ Hodnebrog [Oslash]. et al., 2013 and Javadi et al., 2008.
M.S. Javadi, R. S[oslash]ndergaard, O.J. Nielsen, M.D. Hurley, and
T.J. Wellington, 2008. Atmospheric chemistry of trans-
CF3CH=CHF: products and mechanisms of hydroxyl radical
and chlorine atom-initiated oxidation. Atmospheric Chemistry and
Physics Discussions 8, 1069-1088, 2008.
---------------------------------------------------------------------------

    Flammability information: R-448A, R-449A, and R-449B as formulated,
and even considering the worst-case fractionation for flammability, are
not flammable.
    Toxicity and exposure data: Potential health effects of exposure to
these substitutes include drowsiness or dizziness. The substitutes may
also irritate the skin or eyes or cause frostbite. At sufficiently high
concentrations, the substitutes may cause irregular heartbeat. The
substitutes could cause asphyxiation if air is displaced by vapors in a
confined space. These potential health effects are common to many
refrigerants.
    The American Industrial Hygiene Association (AIHA) has established
workplace environmental exposure limits (WEELs) of 1,000 parts per
million (ppm) as an eight hour time-weighted average (8-hr TWA) for
HFC-32, HFC-125, and HFC-134a, and 500 ppm for HFO-1234yf, the
components of R-448A, R-449A, and R-449B; and 800 ppm for HFO-
1234ze(E), also a component of R-448A. The manufacturer of R-448A
recommends an acceptable exposure limit (AEL) of 890 ppm on an 8-hr TWA
for the blend. The manufacturer of R-449A recommends an AEL of 830 ppm
on an 8-hr TWA for the blend. The manufacturer of R-449B recommends an
AEL of 865 ppm on an 8-hr TWA for the blend. EPA anticipates that users
will be able to meet the AIHA WEELs and manufacturers' AELs and address
potential health risks by following requirements and recommendations in
the manufacturers' safety data sheets (SDS), in American Society of
Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE)
Standard 15, and other safety precautions common to the refrigeration
and air conditioning industry.
    Comparison to other substitutes in this end-use: R-448A, R-449A,
and R-449B have ODPs of zero, comparable to or lower than other
acceptable substitutes in this end-use, with ODPs ranging from zero to
0.098.
    R-448A's GWP of 1,390, R-449A's GWP of 1,400, and R-449B's GWP of
1,410 are higher than those of other acceptable substitutes for retail
food refrigeration--medium-temperature stand-alone units (new),
including ammonia absorption, R-744, R-450A, and R-513A with GWPs
ranging from zero to 630.
    Information regarding the flammability and toxicity of other
available alternatives are provided in the listing decisions previously
made (see https://www.epa.gov/snap/substitutes-stand-alone-equipment).
Flammability and toxicity risks are comparable to or lower than
flammability and toxicity risks of other available substitutes in the
same end-use. Toxicity risks can be minimized by use consistent with
ASHRAE 15 and other industry standards, recommendations in the
manufacturers' safety data sheet (SDS), and other safety precautions
common in the refrigeration and air conditioning industry.
    Although R-448A, R-449A, and R-449B present a higher overall risk
to human health and the environment than other acceptable alternatives
in this end-use category based on significantly higher GWPs than other
available alternatives, with GWPs ranging from zero (ammonia in a
secondary loop) to 630 (R-513A), as provided below, information
suggests that other alternatives may not be available for certain uses
and users of medium-temperature stand-alone equipment. Thus, EPA is
proposing to list these substitutes as acceptable subject to narrowed
use limits in this end-use. The manufacturers of new medium-temperature
stand-alone equipment would need to demonstrate that the other
alternatives are not technically feasible. They must document the
results of their evaluation that showed the other alternatives to be
not technically feasible and maintain that documentation in their
files. This documentation, which does not need to be submitted to EPA
unless requested to demonstrate compliance, ``shall include
descriptions of substitutes examined and rejected, processes or
products in which the substitute is needed, reason for rejection of
other alternatives, e.g., performance, technical or safety standards,
and the anticipated date other substitutes will be available and
projected time for switching to other available substitutes.'' (40 CFR
82.180(b)(3)).
3. Summary of AHRI Petition
    AHRI petitioned EPA under CAA section 612(d) to add R-448A, R-449A,
and R-449B to the list of acceptable substitutes for new and retrofit
medium-temperature stand-alone units. See 40 CFR 82.184 for further
information regarding petitions under the SNAP program. EPA and AHRI
have exchanged information related to this petition between March 2017
and November 2018. Although we are not formally responding to the AHRI
petition or deeming it ``complete'' in this proposed rulemaking, some
of the information received as part of this petition is relevant to the
proposed listing, as discussed below, and EPA's action in this
rulemaking may be considered responsive to certain aspects of this
petition, given that EPA is proposing to list R-448A, R-449A, and R-
449B as acceptable, subject to narrowed use limits, in new medium-
temperature stand-alone units.
    In its petition, AHRI raised claims that refrigerants currently
listed as acceptable are not available for use in all types of
equipment within this end-use category. AHRI's petition addressed

five key points. First, AHRI claims, based on their members' experience
in the industry, that the use of these three refrigerants compared to
the acceptable alternatives is simpler based on their members'
experience and knowledge and on the equipment efficiency and component
supply borne out of EPA's listing of these refrigerants in low-
temperature stand-alone units and other end-use categories. However,
EPA notes that it does not consider the simplicity of designing
equipment to be part of the SNAP criteria. In fact, manufacturer
literature 16 17 18 19 20 shows that there are some medium-
temperature stand-alone units available with the acceptable
alternatives, indicating that at least for some products and some
manufacturers, any complexity issues with designing such equipment have
been resolved.
---------------------------------------------------------------------------

    \16\ CCAC, 2012. Technology Forum on Climate Friendly
Alternatives in Commercial Refrigeration. Meeting Summary. 8
December 2012.
    \17\ Coca-Cola, 2014. Coca-Cola Installs 1 Millionth HFC-Free
Cooler Globally, Preventing 5.25MM Metric Tons of CO2, January 22,
2014.
    \18\ Shecco, 2013a. HCs Gaining Market Prominence in US--View
from the NAFEM Show--Part 1, February 18, 2013.
    \19\ Shecco, 2013b. HCs Gaining Market Prominence in US--View
from the NAFEM Show--Part 2, February 25, 2013.
    \20\ Shecco, 2015. New Regulations Inspire Hydrocarbon Displays
at U.S. NAFEM Show, February 24, 2015.
---------------------------------------------------------------------------

    Second, AHRI claims that the available alternatives are not able to
meet the U.S. Department of Energy (DOE) Energy Conservation Standards
for Commercial Refrigeration Equipment (79 FR 17725, March 28, 2014),
which have a compliance date of March 27, 2017, for some equipment
types. AHRI also indicates there is a lack of components designed for
R-290 for capacities between 3,000 and 12,000 million British thermal
units per hour (MBtu/hour), which preclude that alternative's use in
larger stand-alone units, especially those with open cases (i.e., no
doors). They also state that the 150-gram limit established by EPA as a
use condition for R-290 leads to needing multiple smaller compressor
systems for such larger equipment, which requires more space to house
and leads to equipment designs that would not comply with the ADA.
Further to the point of ADA compliance, AHRI indicates that the
thermodynamic properties of the other alternatives (such as R-450A and
R-513A) are such that larger components are needed to achieve the same
amount of cooling, and that these larger components lead to designs
conflicting with requirements of the ADA such as counter height. AHRI
provided information (see presentation titled ``AHRI Petition for SNAP
Approval of R-448A, R-449A&B In Medium Temperature Stand-Alone
Commercial Refrigeration Equipment'' in Docket EPA-HQ-OAR-2019-0698)
that evaluated the capacity and efficiency of relevant equipment using
R-450A and R-513A, two acceptable alternatives, and for R-448A, R-449A
and R-449B. In the larger units (1 horsepower and above), their results
showed 6% to 29% lower capacities with the two acceptable alternatives
compared to R-404A, while R-448A, R-449A and R-449B showed capacities
up to 7% better compared to R-404A. This information suggests that
certain equipment configurations would require significantly larger
refrigeration equipment that could jeopardize compliance with ADA for
those types of equipment.
    Regarding the efficiency standards, EPA previously noted that
medium-temperature stand-alone units would fall under a classification
ending in .SC.M within the DOE regulations (80 FR 42902, July 20,
2015). Several codes could precede .SC.M to indicate the unit design
(e.g., horizontal or vertical, open or with doors). As also discussed
in that rule, ``EPA does not have a practice in the SNAP program of
including . . . energy efficiency in the overall risk analysis. We do
consider issues such as technical needs for energy efficiency (e.g., to
meet DOE standards) in determining whether alternatives are
`available.' '' However, EPA also explained ``that the refrigerant is
only one of many factors affecting energy efficiency. Moreover, even as
refrigerant transitions have taken place over past decades, we have
seen improved energy efficiency. This is often due to equipment
redesigns and technology advancements that include factors besides the
choice of refrigerant.'' (80 FR 42946, July 20, 2015). Therefore, for
this proposed rule, EPA is not basing our proposed listing decision on
energy efficiency, although the Agency has previously indicated that an
analysis of equipment performance could be part of the evaluation
required to use R-448A, R-449A, and R-449B under the proposed narrowed
use limit.
    Third, AHRI indicates that a design alternative--reconfiguring
stand-alone units into remote condensing units--would likely lead to
higher emissions. EPA listed R-448A, R-449A and R-449B as acceptable
for remote condensing units (80 FR 42053, July 16, 2015; 81 FR 70029,
October 11, 2016). The choice of using such a design alternative,
however, is not germane to this proposal, which is evaluating the use
of these refrigerants in medium-temperature stand-alone equipment.
Therefore, for this proposed rule, EPA is not basing our proposed
listing decision on the fact that such a design alternative exists.
    Fourth, AHRI notes that some equipment is designed to meet both
low- and medium-temperature conditions, requiring more complex designs
with a risk of refrigerant cross-contamination if R-448A, R-449A, or R-
449B was used for the low-temperature range but was not acceptable for
the medium-temperature range. As explained above, the complexity of
designing equipment is not part of the SNAP review criteria.
    Fifth, AHRI claims that the cost to redesign equipment to an
acceptable refrigerant like R-450A or R-513A would be high. EPA noted
in the 2015 Rule that only certain elements of cost are part of the
SNAP criteria. We stated that ``under the SNAP criteria for review in
40 CFR 82.180(a)(7), the only cost information that EPA considers as
part of its SNAP review is the cost of the substitute under review.''
(80 FR 42898, July 15, 2015). Because the cost to redesign equipment is
not part of the SNAP criteria, EPA is not basing our proposed listing
decision on such costs.
4. What is EPA proposing for R-448A, R-449A and R-449B?
    EPA understands that to construct certain medium-temperature stand-
alone units with the available acceptable refrigerants would require
significantly larger components, or the addition of multiple
refrigeration systems, which may lead to redesigning the units in such
a manner that could be inconsistent with the ADA requirements. AHRI
specifically pointed to R-448A, R-449A, and R-449B as refrigerants that
would, on the contrary, be feasible in such equipment and requested
that those refrigerants be added to the list of acceptable refrigerants
for new medium-temperature stand-alone units.
    Given the concern about designing equipment capable of complying
with ADA requirements, EPA is proposing to list R-448A, R-449A, and R-
449B as acceptable, subject to narrowed use limits, for this end-use
category. Users, including manufacturers, using a substitute listed as
acceptable, subject to narrowed use limits, must ascertain that other
substitutes or alternatives are not technically feasible. As explained
in the initial SNAP rulemaking (59 FR 13063, March 18, 1994), under the
narrowed use limit, ``Users are expected to undertake a thorough
technical investigation of alternatives before implementing the
otherwise restricted substitute'' (i.e., R-448A, R-449A or R-

449B for this proposal). Further, ``[t]he Agency expects users to
contact vendors of alternatives to explore with experts whether or not
other acceptable substitutes are technically feasible for the process,
product or system in question'' (i.e., in new medium-temperature stand-
alone units for this proposal) to the otherwise restricted substitute.
The initial SNAP rule also explained that ``[a]lthough users are not
required to report the results of their investigations to EPA,
companies must document these results, and retain them in company files
for the purpose of demonstrating compliance'' for up to five years
after the date of creation of the records. In this circumstance,
``users'' would generally be considered the manufacturers producing
medium temperature stand-alone equipment using one of these three
substitutes. This information includes descriptions of:
     Process or product in which the substitute is needed;
     Substitutes examined and rejected;
     Reason for rejection of other alternatives, e.g.,
performance, technical or safety standards; and/or
     Anticipated date other substitutes will be available and
projected time for switching.
    An example of a viable explanation under a narrowed use limit
should include information such as a market analysis of the components
for other alternatives that indicate a lack of availability in the
required sizes or with required features, or design diagrams that
indicate excessive loss of refrigerated volumes or failure to meet ADA
requirements.
    At this time, EPA does not have sufficient information indicating
that there is any other basis that would preclude use of other
available alternatives. Regarding AHRI's concerns about the cost of
redesigning equipment to use the currently acceptable alternatives, as
explained in previous rulemakings referenced above, EPA does not
consider the cost of transitioning to alternatives in making listing
decisions. In addition, the fact, on its own, that designs using a
safer alternative may be more complex is not a sufficient basis to list
a substitute that poses greater risk as acceptable. EPA is taking
comment on the proposed listings as well as the specific narrowed use
limits discussed above.

B. Residential and Light Commercial Air Conditioning and Heat Pumps--
Proposed Listing of R-452B, R-454A, R-454B, R-454C, and R-457A as
Acceptable, Subject to Use Conditions, for use in Residential and Light
Commercial Air Conditioning and Heat Pumps End-Use for New Equipment;
and R-32 as Acceptable, Subject to Use Conditions, for Use in
Residential and Light Commercial Air Conditioning and Heat Pumps--
Equipment Other Than Self-Contained Room Air Conditioners, for New
Equipment

    EPA previously listed R-32 as acceptable subject to use conditions
as a substitute in residential and light commercial air conditioning
and heat pumps for self-contained room air conditioners, including
packaged terminal air conditioners (PTACs), packaged terminal heat
pumps (PTHPs), window AC units, portable room AC equipment, and wall-
mounted self-contained ACs (80 FR 19454, April 10, 2015).\21\ This
proposed rulemaking is proposing to find R-32 acceptable, subject to
use conditions, for self-contained ACs that are typically larger than
room-size (e.g. rooftop units, water-source heat pumps, and ground-
source heat pumps) and split systems, as explained below, which are
part of the residential and light commercial air conditioning and heat
pump end-use. For convenience, in this proposed rule we discuss the
proposed listing decision for R-32 together with the proposed decision
for R-452B, R-454A, R-454B, R-454C, and R-457A (hereafter called ``the
five refrigerant blends'') but we note here that this proposed decision
for R-32 is not a proposal to revisit or modify the existing acceptable
subject to use conditions listing for R-32 for self-contained room air
conditioners.
---------------------------------------------------------------------------

    \21\ In this proposed rule, we use the term ``air conditioner''
and ``AC'' to cover equipment that cools air, heats air, or has the
function to do both (typically referred to as a ``heat pump'').
While such equipment might humidify or dehumidify the air, the term
does not include equipment whose purpose is for latent cooling only
(i.e., dehumidifiers), which are a separate end-use under SNAP.
---------------------------------------------------------------------------

    EPA proposes to list the five refrigerant blends (i.e., R-452B, R-
454A, R-454B, R-454C, and R-457A) as acceptable subject to use
conditions as substitutes in residential and light commercial air
conditioning and heat pumps for both self-contained and split systems
and R-32 as acceptable subject to use conditions in residential and
light commercial air conditioning and heat pumps for split systems and
for specific types of self-contained systems that are part of the
residential and light commercial air conditioning and heat pump end-use
but for which R-32 has not been previously listed.
    EPA proposes the following use conditions:
    (1) UL Standard--These refrigerants may be used only in AC
equipment, both self-contained equipment and split-systems, that meet
all requirements listed in the 3rd edition, dated November 1, 2019, of
Underwriters Laboratories (UL) Standard 60335-2-40, ``Household And
Similar Electrical Appliances--Safety--Part 2-40: Particular
Requirements for Electrical Heat Pumps, Air Conditioners and
Dehumidifiers'' (UL Standard). If this rule is finalized as proposed,
in cases where the final rule would include requirements different than
those of the 3rd edition of UL Standard 60335-2-40, the appliance would
need to meet the requirements of the final rule in place of the
requirements in the UL Standard. See section II.B.4 of the preamble for
further discussion on the requirements of this standard that EPA is
proposing to incorporate by reference.
    (2) New equipment only--These refrigerants may be used only in new
equipment designed specifically and clearly identified for the
refrigerant; i.e., none of these substitutes may be used as a
conversion or ``retrofit'' refrigerant for existing equipment.
    (3) Warning labels--The following markings, or the equivalent, must
be provided in letters no less than 6.4 mm (\1/4\ inch) high and must
be permanent:
    (a) On the outside of the air conditioning equipment: ``WARNING--
Risk of Fire. Flammable Refrigerant Used. To Be Repaired Only By
Trained Service Personnel. Do Not Puncture Refrigerant Tubing''
    (b) On the outside of the air conditioning equipment: ``WARNING--
Risk of Fire. Dispose of Properly In Accordance With Federal Or Local
Regulations. Flammable Refrigerant Used''
    (c) On the inside of the air conditioning equipment near the
compressor: ``WARNING--Risk of Fire. Flammable Refrigerant Used.
Consult Repair Manual/Owner's Guide Before Attempting to Service This
Product. All Safety Precautions Must be Followed''
    (d) For any equipment pre-charged at the factory, on the equipment
packaging: ``WARNING--Risk of Fire due to Flammable Refrigerant Used.
Follow Handling Instructions Carefully in Compliance with National
Regulations''
    (e) On the indoor unit \22\ near the nameplate:
---------------------------------------------------------------------------

    \22\ This labeling is required for split systems and self-
contained equipment alike.

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

    a. At the top of the marking: ``Minimum Installation height, X m (W
ft)''. This marking is only required if the similar marking is required
by the 3rd edition of UL 60335-2-40. The terms ``X'' and ``W'' shall be
replaced by the numeric height as calculated per the UL Standard. Note
that the formatting here is slightly different than the UL Standard;
specifically, the height in Inch-Pound units is placed in parentheses
and the word ``and'' has been replaced by the opening parenthesis.
    b. Immediately below (a) above or at the top of the marking if (a)
is not required: ``Minimum room area (operating or storage), Y m\2\ (Z
ft\2\)''. The terms ``Y'' and ``Z'' shall be replaced by the numeric
area as calculated per the UL Standard. Note that the formatting here
is slightly different than the UL Standard; specifically, the area in
Inch-Pound units is placed in parentheses and the word ``and'' has been
replaced by the opening parenthesis.
    (f) For non-fixed equipment, including portable air conditioners,
window air conditioners, packaged terminal air conditioners and
packaged terminal heat pumps, on the outside of the product:
``WARNING--Risk of Fire or Explosion--Store in a well-ventilated room
without continuously operating flames or other potential ignition.''
    (g) For fixed equipment, including rooftop units and split air
conditioners, ``WARNING--Risk of Fire--Auxiliary devices which may be
ignition sources shall not be installed in the ductwork, other than
auxiliary devices listed for use with the specific appliance. See
instructions.''
    (4) Markings--Equipment must have distinguishing red
(Pantone[supreg] Matching System (PMS) #185 or RAL 3020) color-coded
hoses and piping to indicate use of a flammable refrigerant. The air
conditioning equipment shall have marked service ports, pipes, hoses
and other devices through which the refrigerant is serviced. Markings
shall extend at least 1 inch (25mm) from the servicing port and shall
be replaced if removed.
    The regulatory text of the proposed decisions appears in tables at
the end of this document. If finalized as proposed, this text would be
codified in appendix W of 40 CFR part 82 subpart G. The proposed
regulatory text contains listing decisions for the end-uses discussed
above. EPA notes that there may be other legal obligations pertaining
to the manufacture, use, handling, and disposal of the proposed
refrigerants that are not included in the information listed in the
tables (e.g., the CAA section 608(c)(2) prohibition on knowingly
venting or otherwise knowingly releasing or disposing of substitute
refrigerants in the course of maintaining, servicing, repairing or
disposing of an appliance or industrial process refrigeration, or
Department of Transportation requirements for transport of flammable
gases). Mildly flammable refrigerants being recovered or otherwise
disposed of from residential and light commercial air conditioning
appliances are likely to be hazardous waste under the Resource
Conservation and Recovery Act (RCRA) (see 40 CFR parts 260-270).
1. Background on Residential and Light Commercial Air Conditioning and
Heat Pumps
    The residential and light commercial air conditioning and heat
pumps end-use includes equipment for cooling air in individual rooms,
in single-family homes, and in small commercial buildings. Heat pumps
are equipment types that heat, or have the option to either cool or
heat, air for such locations. This end-use differs from commercial
comfort AC, which uses chillers that cool water that is then used to
cool air throughout a large commercial building, such as an office
building or hotel. This end-use includes both self-contained and split
systems. Self-contained systems include some rooftop AC units (e.g.,
those ducted to supply conditioned air to multiple spaces) and many
types of room ACs, including PTACs, PTHPs, some rooftop AC units,
window AC units, portable room AC units, and wall-mounted self-
contained ACs, designed for use in a single room. Split systems include
ducted and non-ducted mini-splits (which might also be designed for use
in a single room), multi-splits and variable refrigerant flow (VRF)
systems, and ducted unitary splits. Water-source and ground-source heat
pumps often are packaged systems similar to the self-contained
equipment described above but could be applied with the condenser
separated from the other components similar to split systems. Examples
of equipment for residential and light commercial AC and heat pumps
include:
     Central air conditioners, also called unitary AC or
unitary split systems. These systems include an outdoor unit with a
condenser and a compressor, refrigerant lines, an indoor unit with an
evaporator, and ducts to carry cooled air throughout a building.
Central heat pumps are similar but offer the choice to either heat or
cool the indoor space.
     Multi-split air conditioners and heat pumps. These systems
include one or more outdoor unit(s) with a condenser and a compressor
and multiple indoor units, each of which is connected to the outdoor
unit by refrigerant lines. Non-ducted multi-splits provide cooled or
heated air directly from the indoor unit rather than providing the air
through ducts.
     Mini-split air conditioners and heat pumps. These systems
include an outdoor unit with a condenser and a compressor and a single
indoor unit that is connected to the outdoor unit by refrigerant lines.
Non-ducted mini-splits provide cooled or heated air directly from the
indoor unit rather than being carried through ducts.
     Rooftop AC units. These are units that combine the
compressor, condenser and evaporator in a single package and may
contain additional components for filtration and dehumidification. Most
units also include dampers to control air intake. Rooftop AC units cool
or heat outside air that is then delivered to the space directly
through the ceiling or through a duct network. Rooftop AC units are
common in small commercial buildings such as a single store in a mall
with no indoor passageways between stores (i.e., a ``strip-mall'').
They can also be set up in an array to provide cooling or heating
throughout a larger commercial establishment such as a department store
or supermarket.
     Window air conditioners. These are self-contained units
that fit in a window with the condenser extending outside the window.
     PTACs and PTHPs. These are self-contained units that
consist of a separate, un-encased combination of heating and cooling
assemblies mounted through a wall. PTACs and PTHPs are intended for use
in a single room and use no ducts to carry cooled air and no external
refrigerant lines. Typical applications include motel or dormitory air
conditioners.
     Portable room air conditioners. These are self-contained
units that are designed to be moved easily from room to room, usually
having wheels. They may contain an exhaust hose that can be placed
through a window or door to eject heat to the outside.
     Water-source heat pumps (WSHPs) and ground-source heat
pumps (GSHPs). These are similar to unitary split systems except that
heat is ejected (when in cooling mode) from the condenser through a
second circuit rather than directly with outside air. The second
circuit transfers the heat to the ground, ground water, or another body
of water such as a lake using water, or a brine could be used if
temperatures would risk freezing. Some systems can perform heating in a
similar matter with the refrigerant circuit

running in reverse; regardless, the term ``heat pump'' is most often
used.
    All of these types of air conditioning equipment would be subject
to the listing decisions under this rule for the identified substitutes
if those decisions become final.\23\
---------------------------------------------------------------------------

    \23\ As noted above, self-contained room air conditioners using
R-32 would not be affected by this proposed rule.
---------------------------------------------------------------------------

    Of these types of equipment, window air conditioners, PTACs, PTHPs,
rooftop AC units, portable room air conditioners, and often GSHPs and
WSHPs are self-contained equipment with the condenser, compressor,
evaporator, and tubing all within casing in a single unit. In contrast,
unitary split systems, multi-split systems and mini-split systems have
an outdoor condenser that is separated from an indoor unit. Compared to
split systems, self-contained equipment typically has smaller charge
sizes, has fewer locations that are prone to leak, and is less likely
to require servicing by a technician. These types of air conditioning
equipment--both self-contained and split systems--all fall under the
scope of the UL 60335-2-40 standard ``Household And Similar Electrical
Appliances--Safety--Part 2-40: Requirements for Electrical Heat Pumps,
Air Conditioners and Dehumidifiers.''
2. What are the ASHRAE classifications for refrigerant flammability?
    The American National Standards Institute/American Society of
Heating, Refrigerating and Air Conditioning Engineers (ANSI/ASHRAE)
Standard 34-2019 assigns a safety group classification for each
refrigerant which consists of two to three alphanumeric characters
(e.g., A2L or B1). The initial capital letter indicates the toxicity
and the numeral denotes the flammability. ASHRAE classifies Class A
refrigerants as refrigerants for which toxicity has not been identified
at concentrations less than or equal to 400 ppm by volume, based on
data used to determine threshold limit value-time-weighted average
(TLV-TWA) or consistent indices. Class B signifies refrigerants for
which there is evidence of toxicity at concentrations below 400 ppm by
volume, based on data used to determine TLV-TWA or consistent indices.
    The refrigerants are also assigned a flammability classification of
1, 2, 2L, or 3. Tests for flammability are conducted in accordance with
American Society for Testing and Materials (ASTM) E681 using a spark
ignition source at 140 [deg]F (60 [deg]C) and 14.7 psia (101.3
kPa).\24\ The flammability classification ``1'' is given to
refrigerants that, when tested, show no flame propagation. The
flammability classification ``2'' is given to refrigerants that, when
tested, exhibit flame propagation, have a heat of combustion less than
19,000 kJ/kg (8,169 Btu/lb), and have a lower flammability limit (LFL)
greater than 0.10 kg/m\3\. The flammability classification ``2L'' is
given to refrigerants that, when tested, exhibit flame propagation,
have a heat of combustion less than 19,000 kJ/kg (8,169 BTU/lb), have
an LFL greater than 0.10 kg/m\3\, and have a maximum burning velocity
of 10 cm/s or lower when tested at in dry air at 73.4 [deg]F (23.0
[deg]C) and 14.7 psia (101.3 kPa). The flammability classification
``3'' is given to refrigerants that, when tested, exhibit flame
propagation and that either have a heat of combustion of 19,000 kJ/kg
(8,169 BTU/lb) or greater or have an LFL of 0.10 kg/m\3\ or lower.
---------------------------------------------------------------------------

    \24\ ASHRAE, 2019. ANSI/ASHRAE Standard 34-2019: Designation and
Safety Classification of Refrigerants.
---------------------------------------------------------------------------

    For flammability classifications, refrigerant blends are designated
based on the worst case of formulation for flammability and the worst
case of fractionation for flammability determined for the blend.
[GRAPHIC] [TIFF OMITTED] TP12JN20.030

    Using these safety group classifications, ANSI/ASHRAE Standard 34-
2019 categorizes R-32 and the five refrigerant blends in this section
of the proposed rulemaking in the A2L Safety Group.
3. What are R-32, R-452B, R-454A, R-454B, R-454C and R-457A and how do
they compare to other refrigerants in the same end-use?
    R-32 is a mildly flammable refrigerant, and the five refrigerant
blends are mildly flammable refrigerant blends, all with an ASHRAE
safety classification of A2L. The respective CAS Reg. Nos. of R-32 and
the components of the five refrigerant blends are listed below.
    R-32 is also known as HFC-32 or difluoromethane (CAS Reg. No. 75-
10-5). EPA previously listed R-32 as an acceptable refrigerant for some
types of residential and light commercial air conditioning and heat
pumps end-use categories, specifically self-contained

room air conditioners such as window units. PTACs, PTHPs, portable room
AC, and wall-mounted AC (80 FR 19454, April 10, 2015). As noted above,
this proposal would add a listing for this substitute to include
rooftop units, GSHPs and WSHPs, which are typically self-contained but
not sized for a single room, and various types of split systems.
    R-452B, also known by the trade name ``OpteonTM XL 55,''
and also known as ``Solstice[supreg] L41y,'' is a mildly flammable
blend consisting of 67 percent by weight HFC-32; seven percent HFC-125,
also known as 1,1,1,2,2-pentafluoroethane (CAS Reg. No. 354-33-6); and
26 percent HFO-1234yf, also known as 2,3,3,3-tetrafluoroprop-1-ene (CAS
Reg. No. 754-12-1). R-454A, also known by the trade name
``OpteonTM XL 40,'' is a mildly flammable blend consisting
of 35 percent HFC-32 and 65 percent HFO-1234yf. R-454B, also known by
the trade names ``OpteonTM XL 41'' and ``Puron
AdvanceTM,'' is a mildly flammable blend consisting of 68.9
percent HFC-32 and 31.1 percent HFO-1234yf. R-454C, also known by the
trade name ``OpteonTM XL 20,'' is a mildly flammable blend
consisting of 21.5 percent HFC-32 and 78.5 percent HFO-1234yf. R-457A,
also known by the trade name ``Forane[supreg] 457A,'' is a mildly
flammable blend consisting of 70 percent HFO-1234yf, 18 percent HFC-32,
and 12 percent HFC-152a, which is also known as ethane, 1,1-difluoro
(CAS Reg. No. 75-37-6).
    Redacted submissions and supporting documentation for R-32 and the
five refrigerant blends are provided in the docket for this proposed
rule (EPA-HQ-OAR-2019-0698) at https://www.regulations.gov. EPA
performed an assessment to examine the health and environmental risks
of each of these substitutes. These assessments are available in the
docket for this proposed rule.25 26 27 28 29 30
---------------------------------------------------------------------------

    \25\ ICF, 2020d. Risk Screen on Substitutes in Residential and
Light Commercial Air-Conditioning and Heat Pumps (New Equipment);
Substitute: HFC-32.
    \26\ ICF, 2020e. Risk Screen on Substitutes in Residential and
Light Commercial Air-Conditioning and Heat Pumps (New Equipment);
Substitute: R-452B.
    \27\ ICF, 2020f. Risk Screen on Substitutes in Residential and
Light Commercial Air-Conditioning and Heat Pumps (New Equipment);
Substitute: R-454A.
    \28\ ICF, 2020g. Risk Screen on Substitutes in Residential and
Light Commercial Air-Conditioning and Heat Pumps (New Equipment);
Substitute: R-454B.
    \29\ ICF, 2020h. Risk Screen on Substitutes in Residential and
Light Commercial Air-Conditioning and Heat Pumps (New Equipment);
Substitute: R-454C.
    \30\ ICF, 2020i. Risk Screen on Substitutes in Residential and
Light Commercial Air-Conditioning and Heat Pumps; Substitute (New
Equipment): R-457A.
---------------------------------------------------------------------------

    Environmental information: R-32 and the five refrigerant blends
have ODPs of zero.
    R-32 has a GWP of 675. The five refrigerant blends are made up of
the components HFC-32, HFC-125, HFO-1234yf and HFC-152a, which have
GWPs of 675, 3,500, one to four, and 124, respectively.\31\ If these
values are weighted by mass percentage, then R-452B, R-454A, R-454B, R-
454C and R-457A have GWPs of about 700, 240, 470, 150 and 140
respectively.
---------------------------------------------------------------------------

    \31\ See section II.A.2 for sources of these GWP values.
---------------------------------------------------------------------------

    HFC-32, HFC-125, HFC-134a, HFC-152a, HFO-1234yf and HFO-1234ze(E)--
the components of the five refrigerant blends--and R-32 are excluded
from the definition of VOC under CAA regulations (see 40 CFR 51.100(s))
addressing the development of SIPs to attain and maintain the NAAQS.
Knowingly venting or otherwise knowingly releasing or disposing of
these refrigerants in the course of maintaining, servicing, repairing
or disposing of an appliance or industrial process refrigeration is
prohibited as provided in section 608(c)(2) of the CAA and EPA's
regulations at 40 CFR 82.154(a)(1).
    Flammability information: R-32 and the five refrigerant blends are
mildly flammable. All have an ASHRAE flammability classification of 2L.
    Toxicity and exposure data: Potential health effects of exposure to
these substitutes include drowsiness or dizziness. The substitutes may
also irritate the skin or eyes or cause frostbite. At sufficiently high
concentrations, the substitutes may cause irregular heartbeat. The
substitutes could cause asphyxiation if air is displaced by vapors in a
confined space. These potential health effects are common to many
refrigerants.
    The AIHA has established WEELs of 1,000 ppm as an 8-hr TWA for HFC-
32 and the component refrigerants HFC-125 and HFC-152a; the AIHA has
established a WEEL of 500 ppm as an 8-hr TWA for HFO-1234yf. The
manufacturer of R-452B, R-454A, R-454B, and R-454C recommends AELs,
respectively, of 874, 690, 854, and 615 ppm on an 8-hr TWA for these
blends. EPA anticipates that users will be able to meet the AIHA WEEL
and manufacturers' AELs and address potential health risks by following
requirements and recommendations in the manufacturers' SDS, in ASHRAE
Standard 15, and other safety precautions common to the refrigeration
and air conditioning industry.
    Comparison to other substitutes in this end-use: R-32 and the five
refrigerant blends all have an ODP of zero, the same as other
acceptable substitutes in this end-use.
    R-32 and the five refrigerant blends' GWPs, ranging from 140 to
700, are higher than some of the acceptable substitutes for residential
and light commercial air conditioning and heat pumps, including ammonia
absorption, R-290, and R-441A \32\ with GWPs ranging from zero to
three. R-32 and the five refrigerant blends' GWPs are lower than some
of the acceptable substitutes for residential and light commercial air
conditioning and heat pumps, such as HFC-134a, R-410A, and R-507A with
GWPs of 1,430, 2,090 and 3,990 respectively.
---------------------------------------------------------------------------

    \32\ R-290 and R-441A are only acceptable in new self-contained
room air conditioning equipment, subject to use conditions.
---------------------------------------------------------------------------

    Information regarding the toxicity of other available alternatives
are provided in the listing decisions previously made (see https://www.epa.gov/snap/substitutes-residential-and-light-commercial-air-conditioning-and-heat-pumps). Toxicity risks are comparable to or lower
than toxicity risks of other available substitutes in the same end-use.
Toxicity risks can be minimized by use consistent with ASHRAE 15 and
other industry standards, recommendations in the manufacturers' SDS,
and other safety precautions common in the refrigeration and air
conditioning industry.
    Although flammability risk may be greater than flammability risks
of other available substitutes in the same end-use, this risk can be
minimized by use consistent with ASHRAE 15 and other industry standards
such as UL 60335-2-40, recommendations in the manufacturers' SDS, and
other safety precautions common in the refrigeration and air
conditioning industry. EPA is proposing use conditions to reduce the
potential risk associated with the flammability of these alternatives
so that they will not pose significantly greater risk than other
acceptable substitutes in this end-use.
4. Why is EPA proposing these specific use conditions?
    EPA is proposing to list the five refrigerant blends as acceptable,
subject to use conditions, for use in the residential and light
commercial air conditioning and heat pumps end-use for both self-
contained and splits systems for new equipment. EPA is also proposing
to list R-32 as acceptable,

subject to use conditions, for use in the residential and light
commercial air conditioning and heat pumps end use for split systems
and certain types of self-contained equipment for new equipment. As
explained above, EPA is not proposing to change the existing listing of
R-32 as acceptable, subject to use conditions, in self-contained room
ACs (e.g., window units, PTACs, PTHPs, portable room ACs, and wall-
mounted self-contained ACs). The use conditions are identified in the
listing under subheading II.B, above, and are explained here in greater
detail. The use conditions EPA proposes include conditions requiring
use of each refrigerant in new equipment, which can be specifically
designed for the refrigerant; use consistent with the UL 60335-2-40
industry standard, including testing, charge sizes, ventilation, usage
space requirements, and certain hazard warnings and markings; and
revisions to the requirements for warnings and markings on equipment to
inform consumers and technicians of potential flammability hazards. The
listings with specific use conditions are intended to allow for the use
of these mildly flammable refrigerants in a manner that will ensure
they do not pose a greater overall risk to human health and the
environment than other substitutes in this end-use. We seek comment on
the proposed listings including the specific use conditions discussed
below.
New Equipment Only; Not Intended for Use as a Retrofit Alternative
    EPA is proposing that these refrigerants may be used only in new
equipment \33\ which has been designed to address concerns unique to
flammable refrigerants--i.e., none of these substitutes may be used as
a conversion or ``retrofit'' refrigerant for existing equipment. These
flammable refrigerants were not submitted under the SNAP program to be
used in retrofitted equipment, and no information was provided on how
to address hazards if these flammable refrigerants were to be used in
equipment that was designed for non-flammable refrigerants. Therefore,
EPA is only proposing that these refrigerants may be used in new
equipment which can be properly designed for their use.
---------------------------------------------------------------------------

    \33\ This is intended to mean a completely new refrigeration
circuit containing a new compressor, evaporator, condenser and
refrigerant tubing.
---------------------------------------------------------------------------

Standards
    EPA is proposing that the flammable refrigerants may be used only
in equipment that meets all requirements in UL Standard 60335-2-40,
Edition 3 for air conditioning equipment. This UL Standard indicates
that refrigerant charges greater than a specific amount (called
``m3'' in the UL Standard and based on the refrigerant's
LFL) are beyond its scope and that national standards might apply, such
as for instance ANSI/ASHRAE 15-2019. Because EPA has not evaluated such
situations, this proposal only covers equipment that fits within the
scope of the UL Standard.
    Those participating in the UL 60335-2-40 consensus standards
process (hereafter ``UL'') have tested equipment for flammability risk
in residential applications and evaluated the relevant scientific
studies. Further, UL has developed safety standards including
requirements for construction and system design, for markings, and for
performance tests concerning refrigerant leakage, ignition of switching
components, surface temperature of parts, and component strength after
being scratched. Certain aspects of system construction and design,
including charge size, ventilation, and installation space, and greater
detail on markings, are discussed further below in this section. The UL
60335-2-40 Standard was developed in an open and consensus-based
approach, with the assistance of experts in the air conditioning
industry as well as experts involved in assessing the safety of
products. While similar standards exist from other bodies such as the
International Electrotechnical Commission, we are proposing to rely on
specific UL standards that are most applicable and recognized by the
U.S. market. This approach is the same as that in our previous rules on
flammable refrigerants (e.g. 76 FR 78832, December 20, 2011; 80 FR
19454, April 10, 2015).
    A summary of the requirements of UL 60335-2-40 as they affect the
refrigerants and end-use addressed in this section of our proposal
follows. This summary is offered for information only and does not
provide a complete review of the requirements in this standard.
    Among the provisions in UL 60335-2-40 are limits on the amount of
refrigerant allowed in each type of appliance based on several factors
explained in that standard. The requirements in UL 60335-2-40 would
reduce the risk to workers and consumers.
    The limitations on refrigerant charge size for residential and
light commercial air conditioning and heat pumps would be required in
accordance with UL 60335-2-40, Edition 3. As discussed above in this
section, EPA believes UL standards are most applicable to the U.S.
market and offer requirements developed by a consensus of experts. EPA
is proposing to require charge size limits for each of the proposed
refrigerants by equipment type in accordance with UL 60335-2-40,
Edition 3. Annex GG of the standard provides the charge limits,
ventilation requirements and requirements for secondary circuits. The
standard specifies requirements for installation space of an appliance
(i.e., room floor area) and/or ventilation or other requirements which
are determined according to the refrigerant charge used in the
appliance, the installation location and the type of ventilation of the
location or of the appliance. Within Annex GG, Table GG.1 provides
guidance on how to apply the requirements to allow for safe use of
flammable refrigerants. UL 60335-2-40, Edition 3 contains provisions
for safety mitigation. These mitigation requirements were developed to
ensure the safe use of flammable refrigerants over a range of
appliances. In general, as larger charge sizes are used, more stringent
mitigation requirements are required. In certain applications
refrigerant detection systems (as described in Annex LL, Refrigerant
detection systems for A2L refrigerants) and refrigerant sensors (as
described in Annex MM, Refrigerant sensor location confirmation tests)
such as safety alarms are required. Where mechanical ventilation (i.e.,
fans) is required in accordance with Annex GG or Annex 101.DVG, it must
be initiated by a separate refrigerant detection system either as part
of the appliance or installed separately. In a room with no mechanical
ventilation, Annex GG provides requirements for openings to rooms based
on several factors, including the charge size and the room area. The
minimum opening is intended to be sufficient so that natural
ventilation would reduce the risk of using a flammable refrigerant. The
standard also includes specific requirements for split system
appliances covering construction, instruction manuals, and allowable
charge sizes, mechanical ventilation, safety alarms, and shut off
valves for A2L refrigerants.
    In addition to Annex GG and Table GG.1 mentioned above, UL 60335-2-
40 has a requirement for the maximum charge for an appliance using an
A2L refrigerant. If the appliance is a portable appliance, a non-fixed
factory-sealed single package, or a cord-connected appliance which may
be periodically or seasonally relocated (excluding servicing) by the
end user, there are no

additional requirements for room area, ventilation, or other risk
mitigation if the charge is sufficiently small--under three times the
LFL. Additional requirements exist for charge sizes exceeding three
times the LFL.
Labeling
    As a use condition, EPA is proposing to require labeling of
residential and light commercial air conditioning and heat pump
equipment. EPA would require the warning labels on the equipment
contain letters at least \1/4\ inch high. The label must be permanently
affixed to the equipment. Warning label language requirements are
described in Section II.B of this proposed rule, ``Residential and
light commercial air conditioning and heat pumps end-use.'' The warning
label language is similar to or exactly the same as that required in UL
60335-2-40.
    The major difference between this proposed requirement and the
requirements in Table 101.DVF.1 of UL 60335-2-40 is that the markings
for A2L refrigerants, including R-32 and the five refrigerant blends
(i.e., R-452B, R-454A, R-454B, R-454C and R-457A), are required to be
no less than 3.2 mm (\1/8\ inch) high in the standard instead of 6.4 mm
(\1/4\ inch) as EPA is proposing in this action. EPA believes that it
would be difficult to see warning labels with the minimum lettering
height requirement for A2L refrigerants of \1/8\ inch in the UL
Standard. Therefore, as in the requirements in our previous flammable
refrigerants rules (e.g., 76 FR 78832, December 20, 2011; 80 FR 19454,
April 10, 2015), EPA is proposing that the minimum height for lettering
must be \1/4\ inch as opposed to \1/8\ inch, which will make it easier
for technicians, consumers, retail storeowners, first responders, and
those disposing the appliance to view the warning labels.
    EPA is requesting comment on requiring labeling, the height of the
lettering, and the likelihood of labels remaining on a product
throughout the lifecycle of the product, including its disposal.
Markings
    Our understanding of the UL Standard is that red markings, similar
to those EPA has applied as use conditions in past actions for
flammable refrigerants (76 FR 78832, December 20, 2011; 80 FR 19454,
April 10, 2015), are required by the UL Standard for A2 and A3
refrigerants but not A2L refrigerants. EPA is proposing that such
markings apply to these A2L refrigerants as well to establish a common,
familiar and standard means of identifying the use of a flammable
refrigerant.
    These red markings will help technicians immediately identify the
use of a flammable refrigerant, thereby potentially reducing the risk
of using sparking equipment or otherwise having an ignition source
nearby. The AC and refrigeration industry currently uses red-colored
hoses and piping as means for identifying the use of a flammable
refrigerant based on previous SNAP listings. Likewise, distinguishing
coloring has been used elsewhere to indicate an unusual and potentially
dangerous situation, for example in the use of orange-insulated wires
in hybrid electric vehicles. Currently in SNAP listings, color-coded
hoses or pipes must be used for ethane, HFC-32, isobutane, propane, or
R-441A in certain types of equipment. All such tubing must be colored
red PMS #185 or RAL 3020 to match the red band displayed on the
container of flammable refrigerants under the AHRI Guideline N, ``2016
Guideline for Assignment of Refrigerant Container Colors.'' EPA wants
to ensure that there is adequate notice for technicians and others that
a flammable refrigerant is being used within a particular piece of
equipment or appliance. EPA is also concerned with ensuring adequate
notification of the presence of flammable refrigerants for personnel
disposing of appliances containing flammable refrigerants. As explained
in a previous SNAP rule, one mechanism to distinguish hoses and pipes
is to add a colored plastic sleeve or cap to the service tube. (80 FR
19465, April 10, 2015). The colored plastic sleeve or cap would have to
be forcibly removed in order to access the service tube. This would
signal to the technician that the refrigeration circuit that she/he was
about to access contained a flammable refrigerant, even if all warning
labels were somehow removed. This sleeve would be of the same red color
(PMS #185 or RAL 3020) and could also be boldly marked with a graphic
to indicate the refrigerant was flammable. This could be a cost-
effective alternative to painting or dyeing the hose or pipe.
    EPA is proposing the use of color-coded hoses or piping as a way
for technicians and others to recognize that a flammable refrigerant is
used in the equipment. This would be in addition to the proposed use of
warning labels discussed above. EPA believes having two such warning
methods is reasonable and consistent with other general industry
practices. This approach is the same as that adopted in our previous
rules on flammable refrigerants (e.g., 76 FR 78832, December 20, 2011;
80 FR 19454, April 10, 2015).
5. What additional information is EPA including in these listings?
    EPA is including recommendations, found in the ``Further
information'' column of the regulatory text at the end of this
document, to protect personnel from the risks of using flammable
refrigerants. Similar to our previous listing of flammable refrigerants
for this end-use (80 FR 19454, April 10, 2015), EPA is including
information on the U.S. Occupational Safety and Health Administration
(OSHA) requirements at 29 CFR part 1910, proper ventilation, personal
protective equipment, fire extinguishers, use of spark-proof tools and
equipment designed for flammable refrigerants, and training.
    Since this additional information is not part of the regulatory
decision, these statements would not be binding for the proposed use of
the substitutes under the SNAP program. However, the information so
listed may be binding under other regulatory programs (e.g., worker
protection regulations promulgated by OSHA). The ``Further
Information'' identified in the proposed listing does not necessarily
include all other legal obligations pertaining to the use of the
substitutes. While the items listed would not be legally binding under
the SNAP program, EPA would encourage users of substitutes to apply all
statements in the ``Further Information'' column in their use of these
substitutes if this proposal is finalized. In many instances, the
information simply refers to sound operating practices that have
already been identified in existing industry and/or building codes or
standards. Thus, many of the statements, if adopted, would not result
in the user making significant changes in existing operating practices.
    EPA notes that Annex HH of UL 60335-2-40, Competence of service
personnel, provides guidelines for service personnel to ensure they
receive training specifically to address potential risks of servicing
equipment using flammable refrigerants. Annex HH provides
recommendations that such training cover several aspects relevant to
flammable refrigerants including recognition of ignition sources,
information about refrigerant detectors, and other safety concepts.
Additional training information recommended would address the proper
working procedures for equipment commissioning, maintenance, repair,
decommissioning and disposal. The Agency notes that this section of the
UL Standard is described as informational,

rather than ``normative,'' i.e., it is intended to provide information
but not to be an absolute requirement under the UL standard. Because
Annex HH is informative, rather than normative, it is not a requirement
of the UL Standard and following it would not be required under our
proposed use conditions. Nonetheless, in this proposal, EPA is
providing as ``Further information'' some information on training,
including a recommendation that personnel follow Annex HH.
6. On what aspects is EPA requesting additional comment?
    In the past, when finding flammable refrigerants acceptable subject
to use conditions for self-contained equipment, EPA considered a
requirement for training but decided that industry is better suited
than EPA to design the content of any such training. At the time, this
UL Standard did not exist, and the UL standards that EPA incorporated
by reference did not contain a similar informative annex on training.
EPA expected that the use conditions would be met by work performed at
the factory in a controlled environment. Consistent with past SNAP
rules on flammable refrigerants in refrigeration and air conditioning
equipment (e.g. 76 FR 78832, December 20, 2011; 80 FR 19454, April 10,
2015), EPA is not proposing to require specific training or service
practices. However, the Agency is interested in comments on whether
this approach should still be followed or if, through a separate
rulemaking, EPA should propose to establish training and service
requirements, and, if so, how such a training program might be managed
and to what extent or for which types of products such requirements
should apply. EPA is particularly interested in comments on requiring
training for personnel working with split systems because this
equipment is generally charged in the field. EPA likewise is interested
in comments on the extent to which the use conditions including the UL
Standard requirements can be addressed at the factory by trained
factory employees in a controlled environment with limited access by
the general public, for self-contained equipment and split systems. EPA
will consider these comments in determining whether to initiate a
separate rulemaking to establish specific service practices and
training on the use of flammable refrigerants in this end use.

C. Extruded Polystyrene: Boardstock and Billet--Proposed Listing of
Blends of 40 to 52 Percent HFC-134a by Weight and the Remainder HFO-
1234ze(E); Blends of 40 to 52 Percent HFC-134a With 40 to 60 Percent
HFO-1234ze(E) and 10 to 20 Percent Each Water and CO2 by
Weight; and Blends With Maximum of 51 Percent HFC-134a, 17 to 41
Percent HFC-152a, up to 20 Percent CO2 and one to 13 Percent
Water

    EPA is proposing to list three blends containing HFC-134a as
acceptable blowing agents in extruded polystyrene: Boardstock and
billet (XPS): Blends of 40 to 52 percent HFC-134a by weight and the
remainder HFO-1234ze(E); blends of 40 to 52 percent HFC-134a with 40 to
60 percent HFO-1234ze(E) and 10 to 20 percent each water and
CO2 by weight; and blends with maximum of 51 percent HFC-
134a, 17 to 41 percent HFC-152a, up to 20 percent CO2 and
one to 13 percent water. EPA is also proposing to revise the
unacceptable listing for blends of certain HFCs in XPS for consistency
with the acceptable listings for these blends of HFC-134a.
1. Background on XPS
    The foam blowing end-use for XPS includes insulation for roofing,
walls, floors, and pipes. This type of insulation foam can provide both
thermal insulation and protection against moisture. XPS products have a
variety of sizes and densities with differing technical requirements.
XPS billet consists of thick blocks that may be used for flotation or
for fabrication into shapes, such as for insulation of pipes or
fittings. XPS boards are extruded through a die at high temperatures
(approximately 90 [deg]C). Flammability of the blowing agent and of the
foam formulation is a potential hazard that may be addressed in a
number of ways, including engineering controls such as ventilation and
use of explosion-proof materials and/or use of less flammable blowing
agents. In some cases, foam blowing agents may be pre-blended in a
container. In other cases, multiple blowing agents are introduced
during blowing of the foam, or ``co-blown.''
    UL, Factory Mutual (FM), or another organization may test the final
foam product for consistency with ASTM Standard C578, ``Standard
Specification for Rigid, Cellular Polystyrene Thermal Insulation,'' so
that the foam qualifies for meeting building codes.\34\ The foam
undergoes testing for properties such as density, thermal resistance
(``R-value''), compressive strength, flexural strength, water vapor
permeance, water absorption, dimensional stability, flame spread, and
smoke generation to meet building codes.\35\ Flame spread and smoke
testing is conducted according to ASTM E84, ``Standard Test Method for
Surface Burning Characteristics of Building Materials.'' Flame
retardants may need to be added to the foam's composition to meet flame
spread and smoke testing requirements. There may be additional tests
such as for heat and ultraviolet radiation sensitivity for XPS
manufactured for roofing applications.
---------------------------------------------------------------------------

    \34\ In Canada, the applicable standard is CAN/ULC-S701,
``Standard for Thermal Insulation, Polystyrene, Boards and Pipe
Covering.''
    \35\ Source: Extruded Polystyrene Foam Association, web page for
technical information on standards. http://xpsa.com/tech-info-standards.html.
---------------------------------------------------------------------------

    XPS historically used CFC-12 as a blowing agent and then
transitioned to use of HCFC-22 and/or HCFC-142b. EPA listed HCFC-22 and
HCFC-142b as unacceptable blowing agents as of January 1, 2010 (72 FR
14432, March 28, 2007). HFC-134a and HFC blends, particularly blends of
HFC-134a, became widely used in XPS in the following decade. In the
2015 Rule, EPA changed the status of certain HFCs and HFC blends from
acceptable to unacceptable in XPS as of January 1, 2021, including HFC-
134a, HFC-245fa, HFC-365mfc, and blends thereof.\36\ Recognizing that
multiple steps needed to be taken to transition to other blowing
agents, including research and testing, EPA provided several years for
those actions prior to the change of status date of January 1, 2021.
---------------------------------------------------------------------------

    \36\ As noted above, EPA is developing a future proposed rule to
respond to the court's partial vacatur and remand of the 2015 Rule
and notes that the court decision upheld EPA's listing changes as
being reasonable and not ``arbitrary and capricious.''
---------------------------------------------------------------------------

    Based on recent submissions to EPA, EPA is aware of extensive
research and testing on a number of new blowing agents for use in XPS.
These newer substitutes include HFOs, hydrochlorofluoroolefins, or non-
fluorinated compounds, in some cases co-blown with HFCs. In this notice
of proposed rulemaking (NPRM), EPA is proposing to list as acceptable
three new substitutes for use in XPS.

2. What are blends of 40 to 52 percent HFC-134a and the remainder HFO-
1234ze(E); blends of 40 to 52 percent HFC-134a with 40 to 60 percent
HFO-1234ze(E) and 10 to 20 percent each water and carbon dioxide; and
blends with maximum of 51 percent HFC-134a, 17 to 41 percent HFC-152a,
up to 20 percent CO2 and one to 13 percent water, and how do
they compare to other foam blowing agents in the same end-use?
    EPA is proposing to list as acceptable (1) blends of 40 to 52
percent HFC-134a by weight and the remainder HFO-1234ze(E) for use in
XPS (hereafter referred to as ``HFC-134a/HFO-1234ze(E) blends''); (2)
blends of 40 to 52 percent HFC-134a with 40 to 60 percent HFO-1234ze(E)
and 10 to 20 percent each water and CO2 by weight for use in
XPS (hereafter referred to as ``CO2/water/HFC-134a/HFO-
1234ze(E) blends''); and (3) blends with maximum of 51 percent HFC-
134a, 17 to 41 percent HFC-152a, up to 20 percent CO2 and
one to 13 percent water (hereafter referred to as ``HFC-134a/HFC-152a/
CO2/water blends''). The components of the blends are co-
blown.
    HFC-134a is also known as 1,1,1,2-tetrafluoroethane (CAS Reg. No.
811-97-2). HFC-152a, also known as 1,1, difluoroethane, has CAS Reg.
No. 75-37-6. HFO-1234ze is also known as HFC-1234ze, HFO-1234ze(E) or
trans-1,3,3,3-tetrafluoroprop-1-ene (CAS Reg. No. 29118-24-9).
CO2 has CAS Reg. No. 124-38-9 and water has CAS Reg. No.
7732-18-5.
    Redacted submissions and supporting documentation for these blends
are provided in the docket for this proposed rule (EPA-HQ-OAR-2019-
0698) at https://www.regulations.gov. EPA performed assessments to
examine the health and environmental risks of these substitutes. These
assessments are available in the docket for this proposed
rule.37 38 39
---------------------------------------------------------------------------

    \37\ ICF, 2020j. Risk Screen on Substitutes in Extruded
Polystyrene Boardstock and Billet Foam; Substitute: Blends of 40 to
52 Percent HFC-134a by Weight and the Remainder HFO-1234ze(E) (HFC-
HFO Co-blowing Agents).
    \38\ ICF, 2020k. Risk Screen on Substitutes in Extruded
Polystyrene Boardstock and Billet Foam; Substitute: Blends of 40 to
52 Percent HFC-134a with 40 to 60 Percent HFO-1234ze(E) and 10 to 20
Percent Each Water and CO2 by Weight (Co-blowing Blends).
    \39\ ICF, 2020l. Risk Screen on Substitutes in Extruded
Polystyrene Boardstock and Billet Foam; Substitute: Blends with
Maximum of 51 Percent HFC-134a, 17 to 41 Percent HFC-152a, up to 20
Percent CO2 and One to 13 Percent Water (Blends for Foam
Blowing).
---------------------------------------------------------------------------

    Environmental information: The substitutes have an ODP of zero.
Their components, HFC-134a, HFC-152a, HFO-1234ze(E), CO2,
and water have GWPs of 1,430,\40\ 124,\41\ one to six,\42\ one,\43\ and
less than one,\44\ respectively. If these values are weighted by mass
percentage, then the blends range in GWP from about 580 to 750.\45\
HFC-134a, HFC-152a, HFO-1234ze(E), CO2, and water--
components of the blends--are excluded from the definition of VOC under
CAA regulations (see 40 CFR 51.100(s)) addressing the development of
SIPs to attain and maintain the NAAQS.
---------------------------------------------------------------------------

    \40\ IPCC (2007).
    \41\ IPCC (2007).
    \42\ Hodnebrog et al., 2013 and Javadi et al., 2008.
    \43\ IPCC (2007).
    \44\ Sherwood et al 2018. This paper estimated that water vapor
emitted near Earth's surface due to anthropogenic sources, e.g.
irrigation, would have a GWP of -10-3 to 5 x
10-4. ``The global warming potential of near-surface
emitted water vapour,'' Steven C Sherwood, Vishal Dixit and
Chrys[eacute]is Salomez. Environ. Res. Lett. 13 (2018) 104006.
    \45\ A GWP of 580 corresponds to formulations containing
approximately 40 percent HFC-134a and the remainder HFO-1234ze(E) or
HFO-1234ze(E), CO2 and water or HFC-152a, CO2
and water; a GWP of 750 corresponds to formulations containing 52
percent HFC-134a and the remainder of HFO-1234ze(E) or HFO-
1234ze(E), CO2 and water. or 51 percent HFC-134a and the
remainder HFC-152a, CO2, and water.
---------------------------------------------------------------------------

    Flammability information: The component HFC-152a is moderately
flammable. The other components of the blends are non-flammable at
standard temperature and pressure using the standard test method ASTM
E681. However, at higher temperatures such as the temperatures typical
for extruding XPS, HFC-134a, and HFO-1234ze(E) may be flammable,
particularly at higher humidity levels.\46\ Blends containing 50
percent or more HFC-134a have been found to have acceptable flammable
process stability under conditions of use (i.e., XPS extrusion).\47\
---------------------------------------------------------------------------

    \46\ Bellair and Hood, 2019. Comprehensive evaluation of the
flammability and ignitability of HFO-1234ze, R.J. Bellair and L.
Hood, Process Safety and Environmental Protection 132 (2019) 273-
284. Available online at doi.org/10.1016/j.psep.2019.09.033.
    \47\ DuPont, 2019a. August 23, 2019. Letter from DuPont
Performance Building Solutions to EPA.
---------------------------------------------------------------------------

    Toxicity and exposure data: Potential health effects of this
substitute at lower concentrations include headache, nausea, drowsiness
and dizziness. The substitute may also irritate the skin or eyes or
cause frostbite. At sufficiently high concentrations, it may cause
central nervous system depression and affect respiration. The
substitute could cause asphyxiation, if air is displaced by vapors in a
confined space. These health effects are common to other foam blowing
agents used in this end-use.
    The AIHA has established WEELs of 1,000 ppm as an 8-hr TWA for HFC-
134a and HFC-152a and 800 ppm for HFO-1234ze(E). CO2 has an
eight hour/day, 40 hour/week permissible exposure limit (PEL) of 5000
ppm in the workplace required by OSHA and a 15-minute recommended
short-term exposure limit (STEL) of 30,000 ppm established by the
National Institute for Occupational Safety and Health (NIOSH). EPA
anticipates that users will be able to meet the AIHA WEELs, OSHA PEL,
and NIOSH STEL and address potential health risks by following
requirements and recommendations in the manufacturer's SDSs and other
safety precautions common to the foam blowing industry.
    Comparison to other substitutes in this end-use: HFC-134a/HFO-
1234ze(E) blends, CO2/water/HFC-134a/HFO-1234ze(E) blends,
and HFC-134a/HFC-152a/CO2/water blends have ODPs of zero,
comparable to all other acceptable substitutes in this end-use, such as
HFC-152a, HFO-1234ze(E), methyl formate, and CO2.
    The GWPs of 580 to 750 for the HFC-134a/HFO-1234ze(E) blends, the
CO2/water/HFC-134a/HFO-1234ze(E) blends, and HFC-134a/HFC-
152a/CO2/water blends are higher than those for acceptable
alternatives such as HFC-152a, HFO-1234ze(E), light saturated
hydrocarbons C3-C6 \48\ and methyl formate, with respective GWPs of
124, one to six,\49\ three to ten,\50\ and less than five.\51\
---------------------------------------------------------------------------

    \48\ That is, alkanes with three to six carbons such as butane,
n-pentane, isopentane, and cyclopentane.
    \49\ Hodnebrog et al., 2013 and Javadi et al., 2008.
    \50\ EPA, undated. ``Summary of Substitute Foam Blowing Agents
Listed in SNAP Notice 25.'' Available online at https://www.epa.gov/sites/production/files/2014-11/documents/notice25substitutefoams.pdf.
    \51\ EPA, undated.
---------------------------------------------------------------------------

    Information regarding the flammability and toxicity of other
available alternatives are provided in the listing decisions previously
made (see https://www.epa.gov/snap/substitutes-polystyrene-extruded-boardstock-and-billet). Flammability and toxicity risks of the HFC-
134a/HFO-1234ze(E), the CO2/water/HFC-134a/HFO-1234ze(E)
blends, and HFC-134a/HFC-152a/CO2/water blends are
comparable to or lower than flammability and toxicity risks of other
available substitutes in the same end-use. Toxicity risks can be
minimized by use consistent with the AIHA WEELs, OSHA PEL, NIOSH STEL,
recommendations in the manufacturer's SDSs, and other safety
precautions common in the foam-blowing industry.

3. What is EPA proposing for HFC-134a blends in XPS?
    EPA is proposing to list three specific blends of HFC-134a as
acceptable in XPS. These blends have higher GWPs and are otherwise
comparable or lower in risk than other alternatives listed as
acceptable; however, EPA is taking this action because the Agency
believes that other acceptable alternatives are not generally available
for most needs under this end-use. Information available to the Agency
at the time that the Agency finalized the 2015 Rule indicated that
other substitutes listed as acceptable for this end-use, notably HFC-
152a, HFO-1234ze(E), light saturated hydrocarbons C3-C6, and methyl
formate, should be able to meet product requirements after further
research and testing and thus would be available by January 1, 2021.
Since that time, information provided in multiple SNAP submissions
indicates that despite research and testing over the past several
years, three of these four substitutes--HFO-1234ze(E), light saturated
hydrocarbons C3-C6, and methyl formate--have not been proven to meet
density and testing requirements of building codes and standards, such
as for thermal efficiency, compressive strength, and flame and smoke
generation, necessary for XPS products. One of the three manufacturers
of XPS in the United States has had some success using neat \52\ HFC-
152a as a blowing agent to manufacture some XPS products.
---------------------------------------------------------------------------

    \52\ Individual, unblended blowing agents.
---------------------------------------------------------------------------

    In order for substitutes to be available in this end-use, they must
be capable of blowing foam that meets the technical needs of XPS
products including density and ability to meet testing requirements of
building codes and standards, such as for thermal efficiency,
compressive strength, and flame and smoke generation. EPA considered
relevant information included in multiple SNAP submissions in the
development of this proposal regarding whether foam blowing agents
currently listed as acceptable can be used to produce foam that meets
the performance specifications for XPS foam. The submitter of the
proposed blends presented specific evidence supporting a claim that
other acceptable substitutes have not yet provided sufficient
performance when considering density and testing requirements. In
particular, the submitter provided information developed over five
years evaluating a variety of alternative blowing agents in hundreds of
trials. The submitter indicated that it was having difficulty meeting
requirements for insulation value (``R-value'') with neat acceptable
blowing agents such as HFO-1234ze(E), HFC-152a, and CO2.\53\
Further, the submitter indicated that if in some cases it could meet R-
value requirements with those neat blowing agents, these alternatives
were not able to meet other requirements such as compressive strength,
density and thickness, or fire test results. The submitter also
identified challenges with meeting code requirements for XPS products
manufactured with flammable substitutes (e.g., HFC-152a, light
saturated hydrocarbons C3-C6, and methyl formate) and provided examples
of failed test results.
---------------------------------------------------------------------------

    \53\ DuPont, 2019b. December 17, 2019 Letter from DuPont
Performance Building Solutions to EPA.
---------------------------------------------------------------------------

    Based on all of the evidence before the Agency, it now appears that
only one of the substitutes that the Agency believed at the time of the
2015 Rule would be available for use in XPS foam as of January 1, 2021
is in fact available and likely could only be used to meet the needs
for some portion of the XPS foams market.\54\ The Agency is concerned
about ensuring that the needs of the full XPS foams market in the
United States can be met. In addition to a concern that all of the
needs of the XPS foams market cannot be met, EPA considers it important
that the SNAP program not limit the choice of acceptable substitutes to
only one option, where possible. For these reasons, EPA is proposing to
list additional blowing agent options for XPS that have been proven to
work for this end-use.
---------------------------------------------------------------------------

    \54\ The set of products that may be able to be manufactured
with HFC-152a would account for a minority of the current market for
XPS.
---------------------------------------------------------------------------

    The submitter has tested the three blends with HFC-134a addressed
in this proposal and has found the blends create larger cells in XPS
which can be important for meeting the needed range of densities and
meeting other testing requirements. Thus, by adding these two
substitutes to the list of acceptable substitutes, XPS manufacturers
will have at least three viable substitutes to choose from in
manufacturing XPS products and these substitutes should allow
manufacturers to meet additional needs for XPS foams in the United
States. EPA requests comment on the proposed listing of these blends of
HFC-134a as acceptable in XPS.
    EPA notes that the proposed listings are summarized below. Because
the Agency is not proposing to restrict or prohibit use of these
substitutes in this end-use, it is not proposing regulatory text at the
end of this document that, if finalized, would appear in the CFR. If
EPA were to finalize these listings as proposed, the Agency would
publish them in the preamble to the final rule and would add them to
the list of acceptable substitutes for XPS on EPA's website at https://www.epa.gov/snap/substitutes-polystyrene-extruded-boardstock-and-billet.

                          Summary of Proposed New Listings for XPS Foam Blowing Agents
----------------------------------------------------------------------------------------------------------------
             End-use                   Substitute           Proposed decision            Further information
----------------------------------------------------------------------------------------------------------------
Extruded Polystyrene: Boardstock  Blends of 40 to 52   Acceptable *...............  These blends have GWPs of
 and Billet.                       percent HFC-134a                                  580 to 750, depending on
                                   by weight and the                                 the specific composition.
                                   remainder HFO-                                    Blends containing 50
                                   1234ze(E).                                        percent or more HFC-134a
                                                                                have been found to have
                                                                                acceptable flammable
                                                                                process stability under
                                                                                conditions of use (i.e.,
                                                                                XPS extrusion).
Extruded Polystyrene: Boardstock  Blends of 40 to 52   Acceptable *...............  These blends have GWPs of
 and Billet.                       percent HFC-134a                                  580 to 750, depending on
                                   with 40 to 60                                     the specific composition.
                                   percent HFO-                                      Blends containing 50
                                   1234ze(E) and 10                                  percent or more HFC-134a
                                   to 20 percent each                                have been found to have
                                   water and CO2 by                                  acceptable flammable
                                   weight.                                           process stability under
                                                                                conditions of use (i.e.,
                                                                                XPS extrusion).

Extruded Polystyrene: Boardstock  Blends with maximum  Acceptable *...............  These blends have GWPs of
 and Billet.                       of 51 percent HFC-                                580 to 750, depending on
                                   134a, 17 to 41                                    the specific composition.
                                   percent HFC-152a,                                 Blends containing 50
                                   up to 20 percent                                  percent or more HFC-134a
                                   CO2 and one to 13                                 have been found to have
                                   percent water.                                    acceptable flammable
                                                                                process stability under
                                                                                conditions of use (i.e.,
                                                                                XPS extrusion).
----------------------------------------------------------------------------------------------------------------
* Notwithstanding the unacceptable listings in general for blends of HFC-134a in XPS, EPA is proposing these
  specific blends of HFC-134a to be acceptable in this end-use.

    In light of the Agency's proposal to list the above-mentioned
blends of HFC-134a as acceptable, EPA is proposing to revise the
current unacceptable listing for blends of certain HFCs in XPS in
appendix U to 40 CFR part 82, subpart G. The listing for unacceptable
substitutes in XPS states that HFC-134a, HFC-245fa, HFC-365mfc, and
blends thereof; and Formacel TI, Formacel B, and Formacel Z-6 are
``unacceptable as of January 1, 2021, except where allowed under a
narrowed use limit.'' EPA is proposing to revise the listing of
unacceptable substitutes for XPS in appendix U to read that the
substitutes are ``Unacceptable as of January 1, 2021 except where
allowed under a narrowed use limit or where blends are specifically
listed as acceptable.'' EPA is not opening up for comment other aspects
of this existing listing.

D. Total Flooding: Proposed Removal of Powdered Aerosol E From the List
of Substitutes Acceptable Subject to use Conditions

    Powdered Aerosol E, also marketed under the trade names of FirePro,
FirePro Xtinguish, and FireBan, is generated in an automated
manufacturing process during which the chemicals, in powder form, are
mixed and then supplied to end users as a solid contained within a fire
extinguisher. In the presence of heat, the solid converts to an aerosol
consisting mainly of potassium salts. EPA listed Powdered Aerosol E as
acceptable, subject to use conditions, as a total flooding agent (71 FR
56359, September 27, 2006). The use conditions required that Powdered
Aerosol E be used only in areas that are normally unoccupied, because
the Agency did not have sufficient information at that time supporting
its safe use in areas that are normally occupied. Based on a review of
additional information from the submitter to support the safe use of
Powdered Aerosol E in normally occupied spaces, EPA subsequently
determined that Powdered Aerosol E is also acceptable for use in total
flooding systems for normally occupied spaces (83 FR 50026, October 4,
2018). The listing provides that Powdered Aerosol E is acceptable for
total flooding uses, which includes both unoccupied and occupied
spaces. In the October 2018 listing action, EPA noted that in a
subsequent rulemaking, the Agency would remove the previous listing of
Powdered Aerosol E as acceptable, subject to use conditions since the
use condition is no longer applicable. EPA is proposing to take the
ministerial action of removing that listing for Powdered Aerosol E and
is requesting comment on this proposal.

III. Statutory and Executive Order Reviews

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

    This action is not a significant regulatory action and was
therefore not submitted to the Office of Management and Budget (OMB)
for review.

B. Executive Order 13771: Reducing Regulations and Controlling
Regulatory Costs

    This action is expected to be an Executive Order 13771 deregulatory
action. This proposed rule is expected to provide meaningful burden
reduction because it allows for the use of additional ODS substitutes
and there is no requirement to use the substitutes listed in this
action.

C. Paperwork Reduction Act (PRA)

    This action does not impose any new information collection burden
under the PRA. OMB has previously approved the information collection
activities contained in the existing regulations and has assigned OMB
control number 2060-0226. The approved Information Collection Request
includes five types of respondent reporting and recordkeeping
activities pursuant to SNAP regulations: Submission of a SNAP petition,
filing a Toxic Substances Control Act (TSCA)/SNAP Addendum,
notification for test marketing activity, recordkeeping for substitutes
acceptable subject to use restrictions, and recordkeeping for small
volume uses. This rule contains no new requirements for reporting or
recordkeeping.

D. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic
impact on a substantial number of small entities under the RFA. In
making this determination, the impact of concern is any significant
adverse economic impact on small entities. An agency may certify that a
rule will not have a significant economic impact on a substantial
number of small entities if the rule relieves regulatory burden, has no
net burden or otherwise has a positive economic effect on the small
entities subject to the rule. This action allows the additional options
of using R-32, R-448A, R-449A, R-449B, R-452B, R-454A, R-454B, R-454C,
R-457A, blends of 40 to 52 percent HFC-134a by weight and the remainder
HFO-1234ze(E), blends of 40 to 52 percent HFC-134a with 44 to 58
percent HFO-1234ze(E) and one to two percent each water and
CO2 by weight, and blends with maximum of 51 percent HFC-
134a, 17 to 41 percent HFC-152a, up to 20 percent CO2 and
one to 13 percent water in the specified end-uses, but does not mandate
such use. Users who choose to use R-448A, R-449A, and R-449B must make
a reasonable effort to ascertain that other substitutes or alternatives
are not technically feasible and must document and keep records of the
results of such investigations. Because equipment for R-452B, R-454A,
R-454B, R-454C, and R-457A is not manufactured yet in the U.S. for the
residential and light commercial air conditioning and heat pumps end-
use, no change in business practice is required to meet the use
conditions, resulting in no adverse impact compared to the absence of
this rule. Equipment for R-32 already being manufactured has been
subject to similar use conditions, resulting in no adverse impact
compared to the absence of this rule. Thus, the rule would not impose
new costs on small entities if finalized as proposed. We have

therefore concluded that this action will not impose a significant
adverse regulatory burden for all directly regulated small entities.

E. Unfunded Mandates Reform Act (UMRA)

    This action does not contain any unfunded mandate as described in
UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect
small governments. The action imposes no enforceable duty on any state,
local or tribal governments or the private sector.

F. Executive Order 13132: Federalism

    This action 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.

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

    This action does not have tribal implications as specified in
Executive Order 13175. It will not have substantial direct effects on
tribal governments, on the relationship between the Federal Government
and Indian tribes, or on the distribution of power and responsibilities
between the Federal Government and Indian tribes, as specified in
Executive Order 13175.
    Thus, Executive Order 13175 does not apply to this action. EPA
periodically updates tribal officials on air regulations through the
monthly meetings of the National Tribal Air Association and will share
information on this rulemaking through this and other fora.

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

    This action is not subject to Executive Order 13045 because it is
not economically significant as defined in Executive Order 12866, and
because EPA does not believe the environmental health or safety risks
addressed by this action present a disproportionate risk to children.
The EPA has not conducted a separate analysis of risks to infants and
children associated with this rule. Any risks to children are not
different than the risks to the general population. This action's
health and risk assessments are contained in the comparisons of
toxicity for the various substitutes, as well as in the risk screens
for the substitutes that are proposed to be listed. The risk screens
are in the docket for this rulemaking.

I. Executive Order 13211: Actions That Significantly Affect Energy
Supply, Distribution, or Use

    This action is not subject to Executive Order 13211, because it is
not a significant regulatory action under Executive Order 12866.

J. National Technology Transfer and Advancement Act

    This action involves technical standards. EPA proposes to use and
incorporate by reference portions of the 2019 UL Standard 60335-2-40,
which establishes requirements for the evaluation of residential air
conditioning equipment and safe use of flammable refrigerants, among
other things. The standard is discussed in greater detail in section
II.B.4 of this preamble.
    The 2019 UL Standard 60335-2-40 is available at http://www.shopulstandards.com/ProductDetail.aspx?UniqueKey=36463, and may be
purchased by mail at: COMM 2000, 151 Eastern Avenue, Bensenville, IL
60106; Email<EMAIL_ADDRESS>Telephone: 1-888-853-3503 in
the U.S. or Canada (other countries dial 1-415-352-2178); internet
address: http://ulstandards.ul.com/ or www.comm-2000.com. The cost of
the 2019 UL Standard 60335-2-40 is $440 for an electronic copy and $550
for hardcopy. UL also offers a subscription service to the Standards
Certification Customer Library (SCCL) that allows unlimited access to
their standards and related documents. The cost of obtaining this
standard is not a significant financial burden for equipment
manufacturers and purchase is not required for those selling,
installing, and servicing the equipment. Therefore, EPA proposes that
the UL standard proposed to be incorporated by reference is reasonably
available.

K. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Population

    EPA believes that it is not feasible to quantify any
disproportionately high and adverse human health or environmental
effects from this action on minority populations, low-income
populations and/or indigenous peoples, as specified in Executive Order
12898 (59 FR 7629, February 16, 1994) because for all affected
populations there is no requirement to use any of the alternatives
listed in this action.

IV. References

    Unless specified otherwise, all documents are available
electronically through the Federal Docket Management System, Docket
number EPA-HQ-OAR-2019-0698.

AHRI, 2017. Petition Requesting EPA SNAP Approval of R-448A/449A/
449B for Medium Temperature, Stand-Alone Retail Food Refrigeration
Equipment. Submitted March 20, 2017.
ASHRAE, 2019. ANSI/ASHRAE Standard 34-2019: Designation and Safety
Classification of Refrigerants.
Bellair and Hood, 2019. Bellair, R.J. and Hood, L. Comprehensive
evaluation of the flammability and ignitability of HFO-1234ze.
Process Safety and Environmental Protection 132, 273-284. Available
online at doi.org/10.1016/j.psep.2019.09.033.
CCAC, 2012. Technology Forum on Climate Friendly Alternatives in
Commercial Refrigeration. Meeting Summary. 8 December 2012.
Coca-Cola, 2014. Coca-Cola Installs 1 Millionth HFC-Free Cooler
Globally, Preventing 5.25MM Metric Tons of CO2, January 22, 2014.
DuPont, 2019a. August 23, 2019. Letter from DuPont Performance
Building Solutions to EPA.
DuPont, 2019b. December 17, 2019 Letter from DuPont Performance
Building Solutions to EPA.
EPA, undated. Summary of Substitute Foam Blowing Agents Listed in
SNAP Notice 25. Available online at https://www.epa.gov/sites/production/files/2014-11/documents/notice25substitutefoams.pdf
Hodnebrog, et al., 2013. Hodnebrog, [Oslash]., Etminan, M.,
Fuglestvedt, J.S., Marston, G., Myhre, G., Nielsen, C.J., Shine,
K.P., and Wallington, T.J. (2013). Global Warming Potentials and
Radiative Efficiencies of Halocarbons and Related Compounds: A
Comprehensive Review, Reviews of Geophysics, 51, 300-378. Available
online at doi.org/10.1002/rog.20013.
ICF, 2020a. Risk Screen on Substitutes in Retail Food Refrigeration
(Medium-temperature Stand-alone Units) (New Equipment); Substitute:
R-448A.
ICF, 2020b. Risk Screen on Substitutes in Retail Food Refrigeration
(Medium-temperature Stand-alone Units) (New Equipment); Substitute:
R-449A.
ICF, 2020c. Risk Screen on Substitutes in Retail Food Refrigeration
(Medium-temperature Stand-alone Units) (New Equipment); Substitute:
R-449B.
ICF, 2020d. Risk Screen on Substitutes in Residential and Light
Commercial Air-Conditioning and Heat Pumps (New Equipment);
Substitute: HFC-32.
ICF, 2020e. Risk Screen on Substitutes in Residential and Light
Commercial Air-Conditioning and Heat Pumps (New Equipment);
Substitute: R-452B.
ICF, 2020f. Risk Screen on Substitutes in Residential and Light
Commercial Air-Conditioning and Heat Pumps (New Equipment);
Substitute: R-454A.
ICF, 2020g. Risk Screen on Substitutes in Residential and Light
Commercial Air-Conditioning and Heat Pumps (New Equipment);
Substitute: R-454B.

ICF, 2020h. Risk Screen on Substitutes in Residential and Light
Commercial Air-Conditioning and Heat Pumps (New Equipment);
Substitute: R-454C.
ICF, 2020i. Risk Screen on Substitutes in Residential and Light
Commercial Air-Conditioning and Heat Pumps; Substitute (New
Equipment): R-457A.
ICF, 2020j. Risk Screen on Substitutes in Extruded Polystyrene
Boardstock and Billet Foam; Substitute: Blends of 40 to 52 Percent
HFC-134a by Weight and the Remainder HFO-1234ze(E) (HFC-HFO Co-
blowing Agents).
ICF, 2020k. Risk Screen on Substitutes in Extruded Polystyrene
Boardstock and Billet Foam; Substitute: Blends of 40 to 52 Percent
HFC-134a with 40 to 60 Percent HFO-1234ze(E) and 10 to 20 Percent
Each Water and CO2 by Weight (Co-blowing Blends).
ICF, 2020l. Risk Screen on Substitutes in Extruded Polystyrene
Boardstock and Billet Foam; Substitute: Blends with Maximum of 51
Percent HFC-134a, 17 to 41 Percent HFC-152a, up to 20 Percent
CO2 and One to 13 Percent Water (Blends for Foam
Blowing).
IPCC, 2007. Climate Change 2007: The Physical Science Basis.
Contribution of Working Group I to the Fourth Assessment Report of
the Intergovernmental Panel on Climate Change. Solomon, S., Qin, D.,
Manning, M., Chen, Z., Marquis, M., Averyt, K.B., Tignor, M., and
Miller, H.L. (eds.). Cambridge University Press. Cambridge, United
Kingdom and New York, NY, USA. Available online at: www.ipcc.ch/
publications_and_data/ar4/wg1/en/contents.html.
Javadi et al., 2008. Javadi, M.S., S[oslash]ndergaard, R., Nielsen,
O.J., Hurley, M.D., and Wellington, T.J., (2008). Atmospheric
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