[Federal Register Volume 80, Number 69 (Friday, April 10, 2015)]
[Rules and Regulations]
[Pages 19453-19501]
[FR Doc No: 2015-07895]

Vol. 80

Friday,

No. 69

April 10, 2015

Part III

Environmental Protection Agency

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40 CFR Part 82

Protection of Stratospheric Ozone: Listing of Substitutes for
Refrigeration and Air Conditioning and Revision of the Venting
Prohibition for Certain Refrigerant Substitutes; Final Rule

Federal Register / Vol. 80 , No. 69 / Friday, April 10, 2015 / Rules
and Regulations

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 82

[EPA-HQ-OAR-2013-0748; FRL-9922-26-OAR]
RIN 2060-AS04

Protection of Stratospheric Ozone: Listing of Substitutes for
Refrigeration and Air Conditioning and Revision of the Venting
Prohibition for Certain Refrigerant Substitutes

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: Pursuant to the U.S. Environmental Protection Agency's (EPA)
Significant New Alternatives Policy program, this action lists five
flammable refrigerants as acceptable substitutes, subject to use
conditions, in several end-uses: Household refrigerators and freezers,
stand-alone retail food refrigeration equipment, very low temperature
refrigeration, non-mechanical heat transfer, vending machines, and room
air conditioning units. This action also exempts from Clean Air Act
Section 608's prohibition on venting, release, or disposal the four
hydrocarbon refrigerant substitutes listed in this action as
acceptable, subject to use conditions, in specific end-uses. We are
finalizing this exemption for those substitutes, subject to those use
conditions and in those end-uses, on the basis of current evidence that
their venting, release, or disposal does not pose a threat to the
environment.

DATES: This rule is effective on May 11, 2015. The incorporation by
reference of certain publications listed in the rule is approved by the
Director of the Federal Register as of May 11, 2015.

ADDRESSES: EPA has established a docket for this action under Docket ID
No. EPA-HQ-OAR-2013-0748. All documents in the docket are listed on the
www.regulations.gov index. Although listed in the index, some
information is not publicly available, i.e., Confidential Business
Information (CBI) or other information whose disclosure is restricted
by statute. Certain other material, such as copyrighted material, is
not placed on the Internet and will be publicly available only in hard
copy form. Publicly available docket materials are available either
electronically in www.regulations.gov or in hard copy at the Air and
Radiation Docket, EPA/DC, EPA West, Room 3334, 1301 Constitution Avenue
NW., Washington, DC. The Public Reading Room is open from 8:30 a.m. to
4:30 p.m., Monday through Friday, excluding legal holidays. The
telephone number for the Public Reading Room is<PHONE_NUMBER>, and the
telephone number for the Air and Radiation Docket is<PHONE_NUMBER>.

FOR FURTHER INFORMATION CONTACT: Margaret Sheppard, Stratospheric
Protection Division, Office of Atmospheric Programs, Mail Code 6205T,
Environmental Protection Agency, 1200 Pennsylvania Avenue NW.,
Washington, DC 20460; telephone number<PHONE_NUMBER>; fax number (202)
343-2338, email address<EMAIL_ADDRESS>Notices and
rulemakings under EPA's Significant New Alternatives Policy (SNAP)
program are available on EPA's Stratospheric Ozone Web site at
www.epa.gov/ozone/snap/regs.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. General Information
    A. Executive summary
    B. Background
    C. Does this action apply to me?
    D. What acronyms and abbreviations are used in the preamble?
II. How does the SNAP program work?
    A. What are the statutory requirements and authority for the
SNAP program?
    B. What is EPA's regulation implementing Section 612?
    C. How do the regulations for the SNAP program work?
    D. Where do I find additional information about the SNAP
program?
III. What action is the Agency taking?
    A. Listing decisions: Substitutes and end-uses
    B. What are ethane, isobutane, propane, HFC-32, R-441A, and the
ASHRAE classifications for refrigerant flammability?
    C. Use conditions
    D. Venting prohibition
    E. Recommendations for the safe use of flammable substitute
refrigerants
IV. What criteria did EPA consider in determining whether to list
the substitutes as acceptable and in determining the use conditions,
and how does EPA consider those criteria?
    A. Effects on the environment
    B. Flammability
    C. Toxicity and asphyxiation
V. What are the differences between the proposed and final rules?
VI. What are EPA's responses to public comments?
    A. EPA's acceptability determinations
    B. Environmental and public health impacts
    C. Toxicity
    D. Flammability
    E. Use conditions
    F. Technician training
    G. Venting prohibition
    H. Cost and economic impacts
    I. Statutory and executive order reviews
    J. Relationship with other rules
    K. Timing of final rule
    L. Other comments
VII. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination with
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children from
Environmental Health and Safety Risks
    H. Executive Order 13211: Actions that Significantly Affect
Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions to Address
Environmental Justice in Minority Populations and Low-Income
Population
    K. Congressional Review Act (CRA)
VIII. References

I. General Information

A. Executive Summary

    Pursuant to the SNAP program under Clean Air Act (CAA) Section 612,
this final rule lists five flammable refrigerant substitutes as
acceptable, subject to use conditions, in several refrigeration and air
conditioning end-uses: Household refrigerators and freezers; retail
food refrigeration, stand-alone equipment only; very low temperature
refrigeration; non-mechanical heat transfer; vending machines; and room
air conditioning (AC) units. The five refrigerant substitutes are:
Difluoromethane (also known as hydrofluorocarbon (HFC)-32), ethane,
isobutane, propane, and the hydrocarbon blend R-441A. The use
conditions address safe use of flammable refrigerants and include
incorporation by reference of portions of certain safety standards from
Underwriters Laboratories (UL), refrigerant charge size limits, and
requirements for markings on equipment using these refrigerants. This
action also exempts from CAA Section 608's prohibition on venting,
release, or disposal the hydrocarbon refrigerant substitutes ethane,
isobutane, propane, and R-441A in specific end-uses for which they are
being listed in this rulemaking. We are finalizing this exemption for
those substitutes on the basis of current evidence that their venting,
release, or disposal from these specific end-uses does not pose a
threat to the environment.
    This final rule lists all five refrigerants as acceptable, subject
to use conditions, in the same end-uses as in the proposed

rule. This final rule retains the same use conditions as proposed for
household refrigerators and freezers; retail food refrigeration, stand-
alone equipment only; very low temperature refrigeration; non-
mechanical heat transfer; and vending machines. For room AC units, EPA
is retaining the same use conditions as proposed, with one exception.
For portable AC units, EPA is not applying the proposed charge limits
for packaged terminal AC (PTAC) units, packaged terminal heat pumps
(PTHP), and other floor mounted AC units, which are set forth in Table
D. In this final rule, Table E (new) establishes charge limits for
portable AC units, consistent with the requirements in Appendix F of UL
484, ``Room Air Conditioners,'' 8th Edition, dated August 2, 2012. EPA
is making this change because we agree with commenters that the final
rule should incorporate specific provisions for charge limits for
portable units in UL 484, which is the standard that is the basis of
EPA's other charge limits, as well. This final rule exempts the four
hydrocarbon refrigerants for the end-uses addressed in the proposed
rule from the venting prohibition under CAA Section 608. HFC-32 remains
prohibited from being knowingly vented or otherwise knowingly released
or disposed of by any person maintaining, servicing, repairing, or
disposing appliances containing HFC-32.
    EPA received a total of 37 comments from 35 commenters. Major
topics raised by commenters included: The acceptability of each
refrigerant; the environmental, flammability, and toxicity
characteristics of the proposed refrigerants; the cost impacts of using
the proposed refrigerants; the proposed use conditions; EPA's
recommendations for safe handling of the refrigerants; technician
training; the relationship between this proposed rule and the proposed
rule Protection of Stratospheric Ozone: Change of Listing Status for
Certain Substitutes under the Significant New Alternatives Policy
Program (August 6, 2014, 79 FR 46126); and the proposed exemption from
CAA Section 608's prohibition on venting, release, or disposal of the
four hydrocarbon refrigerant substitutes.

B. Background

    Consistent with the Climate Action Plan announced June 2013, which
calls on EPA to ``use its authority through the Significant New
Alternatives Policy Program to encourage private sector investment in
low-emissions technology by identifying and approving climate-friendly
chemicals'' (Climate Action Plan, 2013), this final rule approves a
number of climate-friendly alternatives for various kinds of
refrigeration and AC equipment. Using low-GWP alternatives instead of
high-GWP HFCs reduces climate-damaging emissions. Use and emissions of
HFCs are rapidly increasing because they are the primary substitutes
for ozone-depleting substances, especially in many of the largest end-
uses. Though they represent a small fraction of current total
greenhouse gas (GHG) emissions, their warming impact is hundreds to
thousands of times higher than that of CO2 and other GHGs.
Further, if left unregulated, emissions of HFCs in the United States
are expected to double from current levels of 1.5 percent of GHG
emissions to 3 percent by 2020 and nearly triple by 2030.\1\
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    \1\ Climate Change and President Obama's Action Plan. June,
2013. Available in the docket and online at www.whitehouse.gov/share/climate-action-plan.
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    This action lists as acceptable, subject to use conditions, five
flammable refrigerant substitutes that EPA believes present overall
lower risk to human health and the environment compared to other
available or potentially available alternatives in the same end-uses.
The refrigerants include one HFC refrigerant--HFC-32--and four
hydrocarbon refrigerants--ethane, isobutane, propane, and R-441A. We
are listing these substitutes as acceptable, subject to use conditions,
in a number of stationary AC and refrigeration end-uses under the SNAP
program, including: Household refrigerators and freezers, retail food
refrigeration, very low temperature refrigeration, non-mechanical heat
transfer, vending machines, and residential and light commercial AC and
heat pumps. The use conditions set requirements to ensure that these
substitutes do not present significantly greater risk in the end-use
than other substitutes that are currently or potentially available for
that same end-use. This action is another regular update to EPA's lists
of acceptable substitutes through the SNAP program under the authority
of CAA Section 612.
    This action responds to a number of SNAP submissions for four
hydrocarbon refrigerants and HFC-32. Additionally, this action exempts
from the prohibition under CAA Section 608 on venting, release, or
disposal, the four hydrocarbon refrigerant substitutes that are listed
as acceptable, subject to use conditions, in specific end-uses, on the
basis of current evidence that their venting, release, or disposal does
not pose a threat to the environment. Note, however, that other
applicable environmental regulatory requirements still apply. For
example, for those refrigerant substitutes listed in this action that
contain volatile organic compounds (VOC) as defined in 40 CFR
50.100(s), i.e., isobutane, propane, and R-441A,\2\ a state might adopt
additional control strategies if necessary for an ozone nonattainment
area to attain the National Ambient Air Quality Standard (NAAQS) for
ozone.
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    \2\ Neither ethane nor HFC-32 are VOC under the definition at 40
CFR 51.100(s).
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    With the exception of HFC-32, the refrigerants listed as
acceptable, subject to use conditions, in this action are hydrocarbons
or blends consisting solely of hydrocarbons. Hydrocarbon refrigerants
have been in use for over 15 years in countries such as Germany, the
United Kingdom, Australia, and Japan in household and commercial
refrigerators and freezers. To a lesser extent, hydrocarbon
refrigerants have also been used internationally in small AC units such
as portable room air conditioners.
    Because hydrocarbon refrigerants have zero ozone depletion
potential (ODP) and very low global warming potentials (GWPs) compared
to most other refrigerants, many companies recently have expressed
interest in using hydrocarbons in the United States. Also, some
companies have reported improved energy efficiency with hydrocarbon
refrigerants (A.S. Trust & Holdings, 2012; A/S Vestfrost, 2012; CHEAA,
2013).
    In a final rule published in the Federal Register (FR) on December
20, 2011, at 76 FR 78832, EPA's SNAP program listed isobutane and R-
441A as acceptable, subject to use conditions, in household
refrigerators, freezers, and combination refrigerators and freezers,
and listed propane as acceptable, subject to use conditions, in retail
food refrigerators and freezers (stand-alone units only). In this
action, EPA is listing isobutane, propane, and R-441A as acceptable,
subject to use conditions, in additional end-uses.
    This final action lists HFC-32 (difluoromethane, Chemical Abstracts
Service Registry Number [CAS Reg. No.] 75-10-5) as acceptable, subject
to use conditions, in room air conditioners for residential and light
commercial AC and heat pumps end-use. There appears to be interest in
using HFC-32 for many reasons, including its GWP of 675, which is
considerably lower than the GWPs of hydrochlorofluorocarbon (HCFC)-22
(1,810) and most other HFC-based refrigerants (approximately 1,500 to
4,000) currently used in this end-use. It also has mild flammability
compared to hydrocarbon refrigerants. Mini-split

systems using HFC-32 are now being sold in Japan and are being
introduced in India and Indonesia.
    All of the end-uses in this final rule are for stationary
refrigeration or AC. EPA previously issued several final rules
addressing the use of flammable refrigerants in motor vehicle air
conditioning (MVAC). On June 13, 1995, at 60 FR 31092, the Agency found
all flammable substitutes to be unacceptable for use in MVAC unless
specifically listed as acceptable, subject to use conditions, because
of flammability risks and the lack of sufficient risk assessment and
other relevant information to demonstrate safe use in that end-use at
that time. Some of these risks are unique to motor vehicles. In recent
years, EPA has listed three low-GWP refrigerants as acceptable, subject
to use conditions, for MVAC systems (i.e., R-152a, R-1234yf, and R-
744). Two of these refrigerants are flammable, although less flammable
than hydrocarbons. Under 40 CFR part 82, subpart G, Appendix B, all
other flammable substitutes remain unacceptable for use in MVAC because
EPA has not taken action to specifically list them as acceptable,
subject to use conditions.
    As stated above, this action is being taken under the President's
Climate Action Plan. HFCs are accumulating rapidly in the atmosphere.
For example, the atmospheric concentration of HFC-134a, the most
abundant HFC, has increased by about 10% per year from 2006 to 2012,
and concentrations of HFC-143a and HFC-125 have risen over 13% and 16%
per year from 2007-2011, respectively (Montzka, 2012; NOAA, 2013).
    The alternatives addressed in this action have GWPs significantly
lower than both the ozone-depleting substances (ODS) and HFC substitute
refrigerants in the end-uses in which they are being listed. ODS in the
end-uses in this final rule include chlorofluorocarbon (CFC)-12 (ODP
\3\ of 1 and GWP of 10,900), R-13B1 (also known as
bromotrifluoromethane or halon 1301, with ODP of 10 and GWP of 7,140),
CFC-113 (ODP of 0.8 and GWP of 6,130), R-502 (a blend of CFC-115 and
HCFC-22, with ODP of 0.334 and GWP of 4,660), and HCFC-22 (ODP of 0.055
and GWP of 1,810). The GWPs \4\ of the hydrocarbon refrigerants we are
adding to the SNAP lists in this rule are less than 10, while HFCs
listed as acceptable in the end-uses in this rule have GWPs ranging
from 1,430 to 3,920. Thus, the listed refrigerants provide industry
additional options with lower atmospheric impacts. In this rulemaking,
however, EPA did not limit its review to atmospheric impacts, but
evaluated each of the SNAP criteria for each substitute in each end-use
addressed by this action. EPA then considered overall risk to human
health and the environment for each substitute in comparison to other
available or potentially available alternatives in the same end-uses.
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    \3\ Unless otherwise stated, the ODP values used in this
document are those published in Appendices A and B to Subpart A of
40 CFR part 82. For refrigerant blends, EPA has taken the ODPs for
the component compounds and multiplied them by the weight fraction
of each component in the blend to obtain an approximate ODP.
    \4\ GWPs for HFC-134a, HFC-32, the component HFCs comprising R-
404A and R-410A, propane and ethane are listed in 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., D. Qin, M.
Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller
(eds.)]. Cambridge University Press, Cambridge, United Kingdom and
New York, NY, USA. This document is accessible at www.ipcc.ch/
publications_and_data/ar4/wg1/en/contents.html. GWPs for isobutane
and R-441A were provided by the submitters to EPA and they are
consistent with available information for their components and the
range of GWPs found for other hydrocarbons in IPCC, 2007. For
refrigerant blends, EPA has taken the 100-year integrated time
horizon GWP from IPCC, 2007 for the component compounds and
multiplied them by the weight fraction of each component in the
blend to obtain an approximate GWP. Unless otherwise stated, GWPs
stated in this document are 100-year integrated time horizon values
taken from IPCC, 2007.
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C. Does this action apply to me?

    This action lists the following refrigerants as acceptable, subject
to use conditions, for use in specific end-uses within the
refrigeration and AC sector: Ethane (R-170), HFC-32 (R-32), isobutane
(R-600a), propane (R-290), and the hydrocarbon blend R-441A. Types of
residential and light commercial AC equipment addressed in this action
include window AC units; packaged terminal AC units and heat pumps; and
portable room AC units. Types of refrigeration equipment include stand-
alone retail food refrigeration equipment, very low temperature
freezers, thermosiphons (non-mechanical heat transfer equipment),
household refrigerators and freezers, and vending machines.
    Table 1 identifies industry subsectors that may wish to explore the
use of ethane, HFC-32, R-441A, isobutane, and propane in these end-uses
or that may work with equipment using these refrigerants in the future.

  Table 1--Potentially Regulated Entities by North American Industrial
             Classification System (NAICS) Code or Subsector
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                              NAICS code or    Description of regulated
          Category              subsector              entities
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Industry...................          325412  Pharmaceutical Preparations
                                              (e.g., Capsules,
                                              Liniments, Ointments,
                                              Tablets) Manufacturing.
Industry...................          333415  Manufacturers of
                                              Refrigerators, Freezers,
                                              and Other Refrigerating or
                                              Freezing Equipment,
                                              Electric or Other; Heat
                                              Pumps Not Elsewhere
                                              Specified or Included
                                              (NESOI); and Parts
                                              Thereof.
Industry...................          333415  Air-Conditioning and Warm
                                              Air Heating Equipment and
                                              Commercial and Industrial
                                              Refrigeration Equipment
                                              Manufacturing.
Industry...................          443111  Appliance Stores: Household-
                                              type.
Industry...................          445120  Convenience Stores.
Industry...................          445110  Supermarkets and Other
                                              Grocery (except
                                              Convenience) Stores.
Industry...................          722211  Limited-Service
                                              Restaurants.
Industry...................          238220  Plumbing, Heating, and Air
                                              Conditioning Contractors.
Industry...................          811412  Appliance Repair and
                                              Maintenance.
Industry...................          423930  Recyclable Material
                                              Merchant Wholesalers.
Industry...................          423620  Household Appliances,
                                              Electric Housewares, and
                                              Consumer Electronics
                                              Merchant Wholesalers.
Industry...................          423740  Refrigeration Equipment and
                                              Supplies Merchant
                                              Wholesalers.
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    This table is not intended to be exhaustive, but rather a guide
regarding entities likely to adopt, service or dispose of the
substitutes that are being listed in this action. If you have any
questions about whether this action

applies to a particular entity, consult the person listed in the
preceding section, FOR FURTHER INFORMATION CONTACT.

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

    Below is a list of acronyms and abbreviations used in this
preamble.

AC--air conditioning
ACGIH--American Conference of Governmental Industrial Hygienists
ACH--air changes per hour
AEGL--acute exposure guideline level
AHAM--Association of Home Appliance Manufacturers
AHRI--Air Conditioning, Heating and Refrigeration Institute
AIRAH--Australian Institute of Refrigeration, Air Conditioning and
Heating
ANSI--American National Standards Institute
ARA--Australian Refrigeration Association
ASHRAE--American Society of Heating, Refrigerating and Air-
Conditioning Engineers
BTU--British thermal unit
CAA--Clean Air Act
CAS Reg. No.--Chemical Abstracts Service Registry Number
CARB--California Air Resources Board
CBI--Confidential Business Information
CFC--chlorofluorocarbon
CFR--Code of Federal Regulations
CHEAA--Chinese Household Electrical Appliance Association
CMAQ--Community Multiscale Air Quality
CRA--Congressional Review Act
DOE--the United States Department of Energy
EIA--Environmental Investigation Agency-U.S.
EO--Executive Order
EPA--the United States Environmental Protection Agency
EU--European Union
FR--Federal Register
ft--foot
g--gram
GHG--greenhouse gas
GWP--global warming potential
HCFC--hydrochlorofluorocarbon
HF--hydrogen fluoride
HFC--hydrofluorocarbon
HVACR--heating, ventilation, air conditioning and refrigeration
ICF--ICF International, Inc.
ICOR--ICOR International, Inc.
IEC--International Electrotechnical Commission
in.Hg--inches of mercury
IPCC--Intergovernmental Panel on Climate Change
IPR--industrial process refrigeration
ISRI--Institute of Scrap Recycling Industries
JTG--Joint Task Group
kg--kilogram
kJ--kilojoule
kPa--kilopascal
lb--pound
LFL--lower flammability limit
m--meter
mm--millimeter
MMTCO2eq--million metric tons of carbon dioxide equivalents
MSDS--Material Safety Data Sheet
MVAC--motor vehicle air conditioning
NAAQS--National Ambient Air Quality Standard
NAFEM--North American Association of Food Equipment Manufacturers
NAICS--North American Industrial Classification System
NIOSH--the United States National Institute for Occupational Safety
and Health
NOAA--the United States National Oceanic and Atmospheric
Administration
NOAEL--No Observed Adverse Effect Level
NTTAA--National Technology Transfer and Advancement Act
OEM--original equipment manufacturer
ODP--ozone depletion potential
ODS--ozone-depleting substances
OHA--Office of Hearing and Appeals
OMB--the United States Office of Management and Budget
OSHA--the United States Occupational Safety and Health
Administration
oz--ounce
PPE--personal protective equipment
PEL--permissible exposure limit
PFC--perfluorocarbon
PMS--Pantone Matching System
ppb--parts per billion
ppm--parts per million
ppmv--parts per million by volume
PRA--Paperwork Reduction Act
psi--pounds per square inch
PTAC--packaged terminal air conditioner
PTHP--packaged terminal heat pump
RCRA--Resource Conservation and Recovery Act
REL--Recommended Exposure Limit
RFA--Regulatory Flexibility Act
RSES--Refrigeration Service Engineers Society
SIP--State Implementation Plan
SNAP--Significant New Alternatives Policy
STEL--short-term exposure limit
STP--Standards Technical Panels
TFA--trifluoroacetic acid
The Alliance--The Alliance for Responsible Atmospheric Policy
TLV--threshold limit value
TWA--time-weighted average
UL--Underwriters Laboratories Inc.
UMRA--Unfunded Mandates Reform Act
U.S.C.--United States Code
VOC--volatile organic compounds

II. How does the Significant New Alternatives Policy (SNAP) program
work?

A. What are the statutory requirements and authority for the SNAP
program?

    Section 612 of the CAA requires EPA to develop a program for
evaluating alternatives to ozone depleting substances (ODS). EPA refers
to this program as the Significant New Alternatives Policy (SNAP)
program. The major provisions of Section 612 are the following:
1. Rulemaking
    Section 612(c) requires EPA to promulgate rules making it unlawful
to replace any class I substance (chlorofluorocarbon (CFC), halon,
carbon tetrachloride, methyl chloroform, and hydrobromofluorocarbon) or
class II substance (HCFC) 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
unacceptable for specific uses and to publish a corresponding list of
acceptable alternatives for specific uses. The list of acceptable
substitutes may be found at www.epa.gov/ozone/snap/lists, and the lists
of ``unacceptable,'' ``acceptable subject to use conditions,'' and
``acceptable subject to narrowed use limits'' substitutes are found in
the appendices to Subpart G of 40 CFR part 82 as well as at
www.epa.gov/ozone/snap/lists.
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). The Agency has 90 days to grant or deny
a petition. Where the Agency grants the petition, EPA must publish the
revised lists within an additional six months.
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 new or existing chemicals are introduced into
interstate commerce for significant new uses as substitutes for a class
I substance. The producer must also provide the Agency with the
producer's unpublished health and safety studies on such substitutes.
5. Outreach
    Section 612(b)(1) states that the Administrator shall seek to
maximize the use of federal research facilities and resources to assist
users of class I and II substances in identifying and developing
alternatives to the use of such substances in key commercial
applications.
6. Clearinghouse
    Section 612(b)(4) requires the Agency to set up a public
clearinghouse of alternative chemicals, product substitutes, and
alternative manufacturing processes that are

available for products and manufacturing processes which use class I
and II substances.

B. What is EPA's regulation implementing Section 612?

    On March 18, 1994, EPA published the original rulemaking (59 FR
13044) which established the process for administering the SNAP program
and issued EPA's first lists identifying acceptable and unacceptable
substitutes in the major industrial use sectors (Subpart G of 40 CFR
part 82). These eight sectors--refrigeration and AC; foam blowing;
cleaning solvents; fire suppression and explosion protection;
sterilants; aerosols; adhesives, coatings and inks; and tobacco
expansion--are the principal industrial sectors that historically
consumed the largest volumes of ODS.
    Section 612 of the CAA instructs EPA to list as acceptable those
substitutes that present a lower overall risk to human health and the
environment as compared with other substitutes that are currently or
potentially available for a specific use.

C. How do the regulations for the SNAP program work?

    Under the SNAP regulations, anyone who plans to market or produce a
substitute in one of the eight major industrial use sectors where class
I or class II substances have been used must provide notice to the
Agency, including health and safety information on the substitute, at
least 90 days before introducing it into interstate commerce for
significant new use as an alternative (40 CFR 82.176(a)). This
requirement applies to the persons planning to introduce the substitute
into interstate commerce,\5\ who typically are chemical manufacturers
but may include importers, formulators, equipment manufacturers, and
end users when they are responsible for introducing a substitute into
commerce.\6\ The CAA and the SNAP regulations, 40 CFR 82.174(a),
prohibit use of a substitute earlier than 90 days after notice has been
provided to the Agency. EPA considers that notice has been received
once EPA receives the submission and determines that the submission
includes complete and adequate data (40 CFR 82.180(a)). At that point,
the SNAP review begins.
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    \5\ As defined at 40 CFR 82.104, ``interstate commerce'' means
the distribution or transportation of any product between one state,
territory, possession or the District of Columbia, and another
state, territory, possession or the District of Columbia, or the
sale, use or manufacture of any product in more than one state,
territory, possession or District of Columbia. The entry points for
which a product is introduced into interstate commerce are the
release of a product from the facility in which the product was
manufactured, the entry into a warehouse from which the domestic
manufacturer releases the product for sale or distribution, and at
the site of United States Customs clearance.
    \6\ As defined at 40 CFR 82.172, ``end-use'' means processes or
classes of specific applications within major industrial sectors
where a substitute is used to replace an ODS.
---------------------------------------------------------------------------

    The Agency has identified four possible decision categories for
substitutes that are submitted for evaluation: Acceptable; acceptable
subject to use conditions; acceptable subject to narrowed use limits;
and unacceptable \7\ (40 CFR 82.180(b)). Use conditions and narrowed
use limits are both considered ``use restrictions'' and are explained
below. Substitutes that are deemed acceptable with no use restrictions
(no use conditions or narrowed use limits) can be used for all
applications in the relevant end-uses within the sector. Substitutes
that are acceptable, subject to use conditions, may be used only in
accordance with those restrictions.
---------------------------------------------------------------------------

    \7\ The SNAP regulations also include ``pending,'' referring to
submissions for which EPA has not reached a determination under this
provision.
---------------------------------------------------------------------------

    After reviewing a substitute, the Agency may make a determination
that a substitute is acceptable only if certain conditions are met in
the way that the substitute is used to minimize risks to human health
and the environment. EPA describes such substitutes as ``acceptable
subject to use conditions.'' Entities that use these substitutes
without meeting the associated use conditions are in violation of
Section 612 of the CAA and EPA's SNAP regulations (40 CFR 82.174(c)).
    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.'' A person using a substitute that is
acceptable subject to narrowed use limits in applications and end-uses
that are not consistent with the narrowed use limit is using the
substitute in an unacceptable manner and is in violation of Section 612
of the CAA and EPA's SNAP regulations (40 CFR 82.174(c)).
    The Agency publishes its SNAP program decisions in the Federal
Register. EPA publishes proposed decisions concerning substitutes that
are deemed acceptable subject to use restrictions (use conditions and/
or narrowed use limits), or substitutes deemed unacceptable, as
proposed rulemakings to provide the public an opportunity to comment,
before publishing final decisions.
    In contrast, EPA publishes decisions concerning substitutes that
are deemed acceptable with no restrictions as ``notices of
acceptability'' or ``determinations of acceptability,'' rather than as
proposed and final rules. As described in the preamble to the rule
initially implementing the SNAP program in the Federal Register at 59
FR 13044 on March 18, 1994, EPA does not believe that rulemaking
procedures are necessary to list alternatives that are acceptable
without restrictions because such listings neither impose any sanction
nor prevent anyone from using a substitute.
    Many SNAP listings include ``Comments'' or ``Further Information''
to provide additional information on substitutes. Since this additional
information is not part of the regulatory decision, these statements
are not binding for use of the substitute under the SNAP program.
However, regulatory requirements so listed may be binding under other
regulatory programs (e.g., worker protection regulations promulgated by
the Occupational Safety and Health Administration (OSHA)). The
``Further Information'' identified in the listing does not necessarily
include all other legal obligations pertaining to the use of the
substitute. While the items listed are not legally binding under the
SNAP program, EPA encourages users of substitutes to apply all
statements in the ``Further Information'' column in their use of these
substitutes. 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 require the affected user to make
significant changes in existing operating practices.

D. Where do I find additional information about the SNAP program?

    For copies of the comprehensive SNAP lists of substitutes or
additional information on SNAP, refer to EPA's Ozone Depletion Web site
at: www.epa.gov/ozone/snap. For more information on the Agency's
process for administering the SNAP program or criteria for evaluation
of substitutes, refer to the SNAP final rulemaking in the Federal
Register at 59 FR 13044 on March 18, 1994, codified at 40 CFR part 82,
Subpart G. A complete chronology of SNAP decisions and the appropriate
citations are found at: www.epa.gov/ozone/snap/chron.html.

III. What action is the Agency taking?

A. Listing Decisions: Substitutes and End-Uses

    In this action, EPA is listing the following refrigerants as
acceptable, subject to use conditions, in the identified end-uses.
    1. Retail food refrigeration. EPA finds isobutane (also referred to
as R-600a) and the hydrocarbon blend R-441A acceptable, subject to use
conditions, as substitutes in retail food refrigeration (new stand-
alone retail food refrigeration equipment only). The use conditions
require the following:
    i. The quantity of the substitute refrigerant (i.e., ``charge
size'') must not exceed 150 g (5.29 oz);
    ii. 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'' \8\
refrigerant for existing equipment;
---------------------------------------------------------------------------

    \8\ Sometimes conversion refrigerant substitutes are
inaccurately referred to as ``drop in'' replacements.
---------------------------------------------------------------------------

    iii. These refrigerants may be used only in stand-alone retail food
refrigeration equipment that meets all requirements listed in
Supplement SB to the 10th edition of UL Standard 471, dated November
24, 2010. In cases where this final rule includes requirements more
stringent than those of the 10th edition of UL Standard 471, the
appliance would need to meet the requirements of the final rule in
place of the requirements in the UL Standard;
    iv. The refrigerator or freezer must have red Pantone Matching
System (PMS) #185 marked pipes, hoses, or other devices through which
the refrigerant passes, to indicate the use of a flammable refrigerant.
This color must be present at all service ports and other parts of the
system where service puncturing or other actions creating an opening
from the refrigerant circuit to the atmosphere might be expected and
must extend a minimum of one (1) inch in both directions from such
locations.
    v. The following markings, or the equivalent, must be provided and
must be permanent:
    (a) ``DANGER--Risk of Fire or Explosion. Flammable Refrigerant
Used. Do Not Use Mechanical Devices To Defrost Refrigerator. Do Not
Puncture Refrigerant Tubing.'' This marking must be provided on or near
any evaporators that can be contacted by the consumer.
    (b) ``DANGER--Risk of Fire or Explosion. Flammable Refrigerant
Used. To Be Repaired Only By Trained Service Personnel. Do Not Puncture
Refrigerant Tubing.'' This marking must be located near the machine
compartment.
    (c) ``CAUTION--Risk of Fire or Explosion. Flammable Refrigerant
Used. Consult Repair Manual/Owner's Guide Before Attempting To Service
This Product. All Safety Precautions Must be Followed.'' This marking
must be located near the machine compartment.
    (d) ``CAUTION--Risk of Fire or Explosion. Dispose of Properly In
Accordance With Federal Or Local Regulations. Flammable Refrigerant
Used.'' This marking must be provided on the exterior of the
refrigeration equipment.
    (e) ``CAUTION--Risk of Fire or Explosion Due To Puncture Of
Refrigerant Tubing; Follow Handling Instructions Carefully. Flammable
Refrigerant Used.'' This marking must be provided near all exposed
refrigerant tubing.
    All of these markings must be in letters no less than 6.4 mm (\1/4\
inch) high.
    Retail food refrigeration includes the refrigeration systems,
including cold storage cases, designed to chill food or keep it at a
cold temperature for commercial sale. Stand-alone retail food
refrigeration equipment includes appliances that use a sealed hermetic
compressor and for which all refrigerant-containing components,
including but not limited to the compressor, condenser, and evaporator,
are assembled into a single piece of equipment before delivery to the
ultimate consumer or user. Such equipment does not require the addition
or removal of refrigerant when placed into initial operation. Stand-
alone equipment is used to chill or to store chilled beverages or
frozen products (e.g., reach-in beverage coolers, stand-alone ice cream
cabinets, and wine coolers in commercial settings).
    This acceptability decision does not apply to large commercial
refrigeration systems such as, but not limited to, remote direct
expansion refrigeration systems typically found in supermarkets. This
acceptability decision also does not apply to walk-in coolers. The SNAP
submission did not apply to these types of systems. Moreover, these
types of equipment typically require larger charges than those
established in this use condition for the end-use addressed in this
rule and are sufficiently different that we would need additional
information before making a listing decision.
    2. Very low temperature refrigeration and non-mechanical heat
transfer. EPA finds ethane (also referred to as R-170) acceptable,
subject to use conditions, in very low temperature refrigeration
equipment and in non-mechanical heat transfer, subject to the same use
conditions described above for isobutane and R-441A in stand-alone
retail food refrigeration equipment.
    Very low temperature refrigeration equipment is intended to
maintain temperatures considerably lower than for refrigeration of
food--for example, -80 [deg]C (-170[emsp14][deg]F) or lower. Examples
of very low temperature refrigeration equipment include medical
freezers and freeze-dryers, which generally require extremely reliable
refrigeration cycles to maintain low temperatures and must meet
stringent technical standards. In some cases, very low temperature
refrigeration equipment may use a refrigeration system with two
refrigerant loops or with a direct expansion refrigeration loop coupled
with an alternative refrigeration technology (e.g., Stirling cycle).
This allows a greater range of temperatures and may reduce the overall
refrigerant charge.
    There is no U.S. standard that we are aware of that applies
specifically to very low temperature refrigeration or non-mechanical
heat transfer. The submitter of information for use of ethane in very
low temperature refrigeration has indicated that UL has tested their
equipment for compliance with the UL 471 Standard for commercial
refrigeration equipment, which addresses stand-alone commercial
refrigerators and freezers. In this final rule, we are requiring
compliance with the UL 471 Standard as one of the conditions for use of
ethane in very low temperature refrigeration equipment.
    This submission also addressed the use of ethane in a type of non-
mechanical heat transfer equipment called a thermosiphon. Non-
mechanical heat transfer involves cooling systems that rely on
convection to remove heat from an area, rather than mechanical
refrigeration. A thermosiphon is a type of heat transfer system that
relies on natural convection currents, as opposed to using a mechanical
pump. This final rule lists ethane as acceptable, subject to use
conditions, for use in non-mechanical heat transfer. The use conditions
include a requirement to meet Supplement B to the UL 471 Standard and a
charge limit of 150 g. We note that some other types of non-mechanical
heat transfer equipment would be expected to present different
technical issues than a thermosiphon in a freezer and are not part of
this decision, e.g., equipment designed for cooling the engine
compartment of heavy duty vehicles, organic Rankine cycle equipment, or
geothermal systems.
    3. Household refrigerators and freezers. EPA finds propane (also

referred to as R-290) acceptable, subject to use conditions, as a
substitute in household refrigerators and freezers and combination
refrigerator/freezers. The use conditions require the following:
    i. The charge size for any household refrigerator, freezer, or
combination refrigerator and freezer for each circuit using R-290 must
not exceed 57 g (2.01 oz);
    ii. This refrigerant may be used only in new equipment specifically
designed and clearly identified for the refrigerant--i.e., none of
these substitutes may be used as a conversion or ``retrofit''
refrigerant for existing equipment;
    iii. This substitute may be used only in equipment that meets all
requirements in Supplement SA to the 10th edition of UL Standard 250,
dated August 25, 2000. In cases where this final rule includes
requirements more stringent than those of the 10th edition of UL
Standard 250, the appliance would need to meet the requirements of the
final rule in place of the requirements in the UL Standard;
    iv. The refrigerator or freezer must have red PMS #185 marked
pipes, hoses, and other devices through which the refrigerant passes to
indicate the use of a flammable refrigerant;
    v. Permanent markings must be provided on the equipment, as
described above for stand-alone commercial refrigerators and freezers.
All of these markings must be in letters no less than 6.4 mm (\1/4\
inch) high.
    Household refrigerators, freezers, and combination refrigerator/
freezers are intended primarily for residential use, although they may
be used outside the home. Household freezers only offer storage space
at freezing temperatures, unlike household refrigerators. Products with
both a refrigerator and freezer in a single unit are most common. Wine
coolers used in residential settings are considered part of this end-
use. EPA previously found the flammable hydrocarbon refrigerants
isobutane and R-441A acceptable, subject to use conditions, in this
end-use (December 20, 2011, at 76 FR 78832, codified at Appendix R of
Subpart G of 40 CFR part 82).
    4. Vending machines. EPA finds R-441A, isobutane, and propane as
acceptable substitutes in vending machines, subject to the same use
conditions described above for stand-alone retail food refrigeration
equipment, except that paragraph iii. reads as follows:
    Equipment must meet all requirements of Supplement SA to the 7th
edition of UL Standard 541, ``Refrigerated Vending Machines,'' dated
December 30, 2011 (instead of Supplement SB to the 10th edition of UL
471). Supplement SA specifically addressing flammable refrigerants is
very similar to the Supplement SB in the UL 471 Standard for commercial
refrigerators and freezers, and thus, similar requirements apply to
these types of refrigeration equipment. In UL 541, the relevant
references on equipment markings for flammable refrigerants in
Supplement A are Sections SA 6.1.2-SA 6.1.5.
    Vending machines are self-contained units for refrigerating
beverages or food which dispense goods that must be kept cold or
frozen. This end-use differs from other retail food refrigeration
because goods are dispensed, rather than allowing the consumer to reach
in to grab a beverage or food product. The design of the refrigeration
system of a vending machine is similar to that of a self-contained
commercial refrigerator or freezer. Typically the difference lies in
how payment for goods is made and in the selection mechanisms found in
vending machines but not in self-contained commercial refrigerator-
freezers, and possibly the outer casing (e.g., glass doors and open,
reach-in designs are generally used in self-contained commercial
refrigerator-freezers whereas glass wall and other types of casings are
used for vending machines). We are aware that for vending machines, it
is possible to detach easily and replace the refrigeration circuit from
the outer casing of the equipment. In such a situation, replacing the
old refrigeration circuit with a new one within the old casing would be
considered ``new'' equipment and not a retrofit of the old, existing
equipment.
    5. Residential and light commercial AC and heat pumps. EPA finds
propane (also known as R-290), difluoromethane (also known as HFC-32 or
R-32), and R-441A acceptable, subject to use conditions, as substitutes
in residential and light commercial AC for self-contained room air
conditioners, including PTAC units and PTHPs, window AC units, and
portable AC units designed for use in a single room. The use conditions
require the following:
    i. 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;
    ii. These refrigerants may be used only in air conditioners that
meet all requirements listed in Supplement SA to the 8th edition, dated
August 2, 2012, of UL Standard 484, ``Room Air Conditioners.'' In cases
where this final rule includes requirements more stringent than those
of the 8th edition of UL Standard 484, the appliance would need to meet
the requirements of the final rule in place of the requirements in the
UL Standard;
    iii. UL 484 includes charge limits for room air conditioners and
adherence to those charge limits would normally be confirmed by the
installer. In addition to requiring the charge limits in the UL 484
Standard, EPA is requiring the following charge size limits, adherence
to which must be confirmed by the original equipment manufacturer
(OEM). In cases where the charge size limit listed is different from
those determined by UL 484, the smaller of the two charge sizes would
apply. For a review of how these charge size limits were derived, see
``Derivation of Charge Limits for Room Air Conditioners,'' (EPA, 2015)
in the docket. The charge size limit must be determined based on the
type of equipment, the alternative refrigerant used, and the normal
rated capacity of the unit. The limits are presented in Tables 2
through 6 below in Section III.C.3, ``Charge size,'' and in Tables A,
B, C, D and E of the regulatory text at the end of this preamble.
    iv. The air conditioner must have red PMS #185 marked pipes, hoses,
or other devices through which the refrigerant passes to indicate the
use of a flammable refrigerant. This color must be present at all
service ports and other parts of the system where service puncturing or
other actions creating an opening from the refrigerant circuit to the
atmosphere might be expected and must extend a minimum of one (1) inch
in both directions from such locations;
    v. The following markings, or the equivalent, must be provided and
must be permanent:
    (a) On the outside of the air conditioner: ``DANGER--Risk of Fire
or Explosion. Flammable Refrigerant Used. To Be Repaired Only By
Trained Service Personnel. Do Not Puncture Refrigerant Tubing.''
    (b) On the outside of the air conditioner: ``CAUTION--Risk of Fire
or Explosion. Dispose of Properly In Accordance With Federal Or Local
Regulations. Flammable Refrigerant Used.''
    (c) On the inside of the air conditioner near the compressor:
``CAUTION--Risk of Fire or Explosion. Flammable Refrigerant Used.
Consult Repair Manual/Owner's Guide Before Attempting To Service This
Product. All Safety Precautions Must be Followed.''
    (d) For portable air conditioners, PTAC and PTHP, on the outside of
the

product: ``WARNING: Appliance shall be installed, operated and stored
in a room with a floor area larger than ``X'' m\2\ (Y ft\2\).'' The
value ``X'' must be determined using the minimum room size in m\2\
calculated using Appendix F of UL 484. The evaporator must remain no
higher than 0.6 m above the floor.
    (e) For window air conditioners, on the outside of the product:
``WARNING: Appliance shall be installed, operated and stored in a room
with a floor area larger than ``X'' m\2\ (Y ft\2\).'' The value ``X''
must be determined using the minimum room size in m\2\ calculated using
Appendix F of UL 484. The evaporator must remain no higher than 1.06 m
above the floor. All of these markings must be in letters no less than
6.4 mm (\1/4\ inch) high.
    The residential and light commercial AC and heat pumps end-use
includes equipment for cooling air in individual rooms, in single-
family homes, and sometimes in small commercial buildings. 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. 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. These systems are not addressed in this rule.\9\
---------------------------------------------------------------------------

    \9\ EPA has received submissions for HFC-32 and the hydrocarbon
blends R-441A and R-443A, and no other flammable refrigerants, in
new unitary central air conditioners.This action does not address
flammable refrigerants in unitary central air conditioners.
Introduction into interstate commerce of refrigerants without giving
timely and adequate notice to EPA is in violation of Section 612(e)
of the CAA and the SNAP regulations at 40 CFR part 82, subpart G.
---------------------------------------------------------------------------

     Multi-split air conditioners. 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. These systems are not addressed in this rule.
     Mini-split air conditioners. 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. Cooled air
exits directly from the indoor unit rather than being carried through
ducts. These systems are not addressed in this rule.
     Window air conditioners. These are self-contained units
that fit in a window with the condenser extending outside the window.
These types of units are regulated under this rule.
     PTAC and PTHP. These are self-contained units that consist
of a separate, un-encased combination of heating and cooling assemblies
mounted through a wall.\10\ These types of units are regulated under
this rule.
---------------------------------------------------------------------------

    \10\ Packaged terminal air conditioners are intended for use in
a single room, or potentially for two rooms next to each other, and
use no external refrigerant lines. Typical applications include
motel or dormitory air conditioners.
---------------------------------------------------------------------------

     Portable room air conditioners. These are self-contained,
factory-sealed, single package units that are designed to be moved
easily from room to room and are intended to provide supplemental
cooling within a room. These units typically have wheels or casters for
portability and, under the UL 484 Standard for room air conditioners,
must have a fan which operates continuously when the unit is on.
Portable room air conditioners may contain an exhaust hose that can be
placed through a window or door to eject heat to the outside. These
types of units are regulated under this rule.
    Of these types of equipment, window air conditioners, PTAC, PTHP,
and portable room air conditioners are self-contained equipment with
the condenser, compressor, evaporator, and tubing all within casing in
a single unit. These units all fall under the scope of the UL 484
Standard for room air conditioners. 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, thereby causing refrigerant releases. A
lower risk of refrigerant releases and a potential for smaller releases
and lower concentration releases results in lower risk that flammable
refrigerant could be ignited. Thus, self-contained air conditioners and
heat pumps using a flammable refrigerant have lower risk for fire than
split systems using a flammable refrigerant. EPA notes that split
system AC systems present different technical challenges than self-
contained room AC equipment and are not part of this decision.
    6. Summary. In summary, EPA is listing ethane, isobutane, propane,
HFC-32, and R-441A as acceptable, subject to use conditions, as
substitute refrigerants in certain refrigeration and AC end-uses. It is
legal to use those refrigerants in the specified types of equipment
under the conditions identified above. Use in the specified types of
equipment that is not consistent with the use conditions is a violation
of CAA Section 612 and EPA's implementing regulations for the SNAP
program. Both the equipment manufacturers and the end users must comply
with these use conditions.
    The regulatory text of our decisions for the end-uses discussed
above appears in tables at the end of this preamble. This text will be
codified at 40 CFR part 82 Subpart G. We note that there may be other
legal obligations pertaining to the manufacture, use, handling, and
disposal of hydrocarbons that are not included in the information
listed in the tables (e.g., Section 608 prohibition on venting,
releasing, or disposing of refrigerant substitutes or Department of
Transportation requirements for transport of flammable gases).
    B. What are ethane, isobutane, propane, HFC-32, R-441A, and the
ASHRAE classifications for refrigerant flammability?
    Ethane, isobutane, and propane are hydrocarbons and R-441A is a
hydrocarbon blend. Hydrocarbons are highly flammable organic compounds
made up of hydrogen and carbon. Ethane has two carbons, the chemical
formula of C2H6, and the CAS Reg. No. 74-84-0.
Propane has three carbons, the formula C3H8, and
the CAS Reg. No. 74-98-6. Isobutane has four carbons, the formula
C4H10, also written as
CH(CH3)2CH3 to distinguish it from n-
butane, and the CAS Reg. No. 75-28-5. As refrigerants, ethane, propane,
and isobutane can be referred to by the American Society of Heating,
Refrigerating and Air-Conditioning Engineers (ASHRAE) designations R-
170, R-290, and R-600a, respectively. R-441A, also known by the trade
name ``HCR-188C,'' is a hydrocarbon blend \11\ consisting of 55%
propane, 36% n-butane, 6% isobutane, and 3% ethane by weight.
---------------------------------------------------------------------------

    \11\ EPA notes that under the SNAP program, we review and list
refrigerants with specific compositions (59 FR 13044; March 18,
1994). To the extent possible, we follow ASHRAE's designations for
refrigerants. Blends of refrigerants must be reviewed separately.
For example, we consider each blend of propane with isobutane to be
a different and unique refrigerant, and each would require separate
submission, review and listing. Thus, blends of the refrigerants
that we are listing as acceptable, subject to use conditions, in
this rule are not acceptable.
---------------------------------------------------------------------------

    HFC-32 is a mildly flammable organic compound made up of hydrogen,

carbon, and fluorine with the chemical formula
CF2H2 (CAS Reg. No. 75-10-5).
    The American National Standards Institute (ANSI)/ASHRAE Standard
34-2010 assigns a safety group classification for each refrigerant
which consists of two alphanumeric characters (e.g., A2 or B1). The
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 parts per million (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,
or 3. Tests are conducted in accordance with ASTM E681 using a spark
ignition source at 60 [deg]C and 101.3 kPa (ASHRAE, 2010). Figure 1 in
ANSI/ASHRAE Standard 15-2007 uses the same safety group but limits its
concentration to 3,400 ppm.
    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 (8,174 British thermal units (BTU)/lb), and have a lower
flammability limit (LFL) greater than 0.10 kg/m\3\. Refrigerants within
flammability classification 2 may optionally be designated in the LFL
subclass ``2L'' if they have a maximum burning velocity of 10 cm/s or
lower when tested at 23.0 [deg]C and 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 (8,174 BTU/lb) or greater or an LFL of 0.10 kg/m\3\ or
lower. Thus, refrigerants with flammability classification ``3'' are
highly flammable, while those with flammability classification ``2''
are less flammable and those with flammability classification ``2L''
are mildly flammable. For both toxicity and flammability
classifications, refrigerant blends are designated based on the worst-
case of fractionation determined for the blend (which may be different
when evaluating toxicity than when evaluating flammability).
[GRAPHIC] [TIFF OMITTED] TR10AP15.000

    Using these safety group classifications, ANSI/ASHRAE Standard 34-
2010 categorizes ethane, isobutane, propane, and R-441A in the A3
Safety Group and categorizes HFC-32 in the A2L Safety Group.

C. Use Conditions

    EPA is listing ethane, isobutane, propane, HFC-32, and R-441A as
acceptable, subject to use conditions, in the specified end-uses. The
use conditions include conditions consistent with industry standards,
limits on charge size, and 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 flammable refrigerants in a manner that will
ensure they do not pose a greater risk to human health or the
environment than other substitutes that are currently or potentially
available.
1. New Equipment Only; Not Intended for Use as a Retrofit Alternative
    The refrigerants listed in this final rule may be used only in new
equipment \12\ 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. The
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 of flammable refrigerants when used in equipment
that was designed for non-flammable refrigerants. Introduction into
interstate commerce of these refrigerants for use in existing
equipment, or for other end-uses, without giving timely and adequate
notice to EPA is in violation of Section 612(e) of the CAA and the SNAP
regulations at 40 CFR part 82, subpart G. In addition, use of these
refrigerants in existing equipment is in violation of Section 612(c) of
the CAA and the corresponding SNAP regulations at 40 CFR part 82,
subpart G.
---------------------------------------------------------------------------

    \12\ This is intended to mean a completely new refrigeration
circuit containing a new evaporator, condenser and refrigerant
tubing.
---------------------------------------------------------------------------

2. Standards
    The flammable refrigerants may be used only in equipment that meets
all requirements in the relevant supplements for flammable refrigerants
in certain applicable UL standards for refrigeration and AC equipment.
Specifically, the cited supplements include Supplement SB to UL 471
10th edition for commercial refrigerators and freezers (including
stand-alone freezers

for very low temperature refrigeration), Supplement SA to UL 250 10th
edition (for household refrigerators and freezers), Supplement SA to UL
541 7th edition for refrigerated vending machines, and Supplement SA to
UL 484 8th edition for room air conditioners.
    UL has tested equipment for flammability risk in household and
retail food refrigeration, vending machines, and room AC. Further, UL
has developed acceptable safety standards including requirements for
construction, for markings, and for performance tests concerning
refrigerant leakage, ignition of switching components, surface
temperature of parts, and component strength after being scratched.
These standards were developed in an open and consensus-based approach,
with the assistance of experts in the refrigeration and AC 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 (IEC), this rule relies on UL standards
because they are most applicable and recognized by the U.S. market.
i. Incorporation by Reference
    This approach is the same as that in our previous rule on flammable
refrigerants (December 20, 2011 at 76 FR 78832), through which EPA
incorporated by reference to 40 CFR part 82, appendix R to subpart G,
Supplement SA to UL 250 10th edition and Supplement SB to UL 471 10th
edition. Through this action the EPA is incorporating by reference
relevant supplements from two additional UL standards: Supplement SA to
UL 541 7th edition and Supplement SA to UL 484 8th edition. These
supplements are summarized elsewhere in this document.
    The UL Standards are available for purchase 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
+1-415-352-2168); Internet address: http://ulstandardsinfonet.ul.com/
or www.comm-2000.com. The cost of a single standard is $400-$500 for
electronic and $500-$630 for hardcopy. An outline of UL 484 may be
purchased for $150 electronically or $175 for a 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 these standards is not a
significant financial burden for equipment manufacturers and purchase
is not required for those selling, installing and servicing the
equipment. Therefore, EPA concludes that the UL standards being
incorporated by reference are reasonably available.
3. Charge Size
    The refrigerants listed in this final rule are subject to use
conditions that limit the amount of refrigerant allowed in each type of
appliance. Consistent with previous actions, EPA believes it is
necessary to set limits on charge size in order for these refrigerants
not to pose a risk to human health or the environment that is greater
than the risk posed by other available substitutes. These limits will
reduce the risk to workers and consumers since under worst-case
scenario analyses, a leak of the maximum charge sizes allowed under the
use conditions did not result in concentrations of the refrigerant that
met or exceeded the LFL, as explained below in Section IV.B,
``Flammability.''
    The limitations on refrigerant charge size for household and stand-
alone retail food refrigeration equipment, vending machines, and room
AC units reflect the UL 250, UL 471, UL 541 and UL 484 Standards. As
discussed above in Section III.C.2, ``Standards,'' we believe UL
standards are most applicable to the U.S. market and offer requirements
developed by a consensus of experts. EPA is requiring a charge size not
to exceed 57 g (2.01 oz) for household refrigerators and freezers, not
to exceed 150 g (5.29 oz) for retail food refrigeration in stand-alone
units, and not to exceed 150 g (5.29 oz) for vending machines. The
maximum charge size limit for room AC units varies, as discussed below.
To place these quantities in context, the charge size of a disposable
lighter is approximately 30 g (1.06 oz).
    The UL 250 Standard for household refrigerators and freezers limits
the amount of refrigerant that may leak to no more than 50 g (1.76 oz).
EPA is requiring a charge size of 57 g (2.01 oz) to allow for up to 7 g
(0.25 oz) of refrigerant that might be solubilized in the oil (and
assumed not to leak or immediately vaporize with the refrigerant in
case of a leak). EPA bases this estimate on information received from a
manufacturer of hydrocarbon-based refrigerator-freezers (see EPA-HQ-
OAR-2009-0286-0033 on www.regulations.gov).
    UL Standards 471 (retail food refrigeration) and 541 (vending
machines) limit the amount of refrigerant leaked to 150 g (5.29 oz).
Furthermore, the charge size limit for A3 refrigerants (for retail food
refrigeration) is in line with the IEC 60335-2-89 Standard for
commercial appliances, which has a charge size limit of 150 g (5.29
oz).
    As noted above, EPA is requiring a varying charge size for room AC
units. The maximum charge must be no greater than the amount calculated
for a given sized space according to Appendix F to Supplement SA of UL
Standard 484. This section of the UL standard uses a formula for the
charge of a fixed room air conditioner based upon the size of the space
where the refrigerant may escape and the LFL of the refrigerant. Height
of the mounting of the unit is also a variable, because empirical
studies have found that leaked refrigerant is more likely to mix
thoroughly with the surrounding air, rather than pooling, when the AC
unit is mounted higher. The formula is as follows:
[GRAPHIC] [TIFF OMITTED] TR10AP15.001

Where,
Mmax is the maximum charge size allowed for the space, in
kg,
LFL is the lower flammability limit of the refrigerant in kg/m\3\,
h0 is the installation height of the indoor unit in m
(0.6 m for an AC unit on the floor, 1.0 m for an AC unit in a
window, 1.8 m for a wall-mounted AC unit, and 2.2 m for a ceiling-
mounted AC unit), and
A is the floor area of the room, in m\2\.

    The equipment manufacturer would then design AC units to be used in
rooms with a minimum size and would label the minimum room size on the
equipment.
    In addition to the formula above, UL 484 has a requirement that the
maximum charge for a fixed room air conditioner may not exceed the
amount calculated using the following formula:

m2 = (26 m\3\) x LFL

Where,
m2 is the maximum charge size allowed, in kg,
26 m\3\ is a constant, and
LFL is the lower flammability limit of the refrigerant in kg/m\3\.

    That formula sets maximum limits on refrigerant in a room air
conditioner. With the A3 refrigerants, the maximum value is 1 kg.
    In addition, Appendix F of UL 484 sets alternative requirements for
non-fixed units such as portable air conditioners. Portable air
conditioners are usually located on the floor of a room, and thus, if
they followed the formula for fixed appliances, they would be assumed
to have a height of 0.6 m, and would have relatively low charge sizes.
However, Sections F.1.7 uses a different formula that allows for

a potentially larger charge size for non-fixed units. Sections F.1.8
through F.1.14 of UL 484 set additional requirements for non-fixed
units to further reduce flammability risk. Among these provisions are
requirements for a drop test, a vibration test, and a continuously
operating fan, which would ensure that any leaked refrigerant is
rapidly mixed and its concentration reduced. Thus, a different approach
is used in the formula for determining charge sizes of non-fixed units;
for example, the height of 0.6 m that might otherwise be assumed for
PTACs is not used for a portable unit.
    Although using a formula to determine the maximum charge size and
minimum room size is appropriate from an engineering perspective, it
does not ensure that a consumer will select an appropriate AC unit for
the size of their room. It is likely that some consumers may be unaware
of the exact size of the room to be cooled and thus may select an
inappropriately sized AC unit that increases the flammability risk. Or,
a consumer may believe that a larger, more powerful AC unit will
provide better, faster cooling and therefore may select an
inappropriately sized AC unit that increases the flammability risk. To
address these concerns, EPA is supplementing the charge size guidelines
in Appendix F of UL 484 with a use condition that restricts the maximum
refrigerant charge of equipment based upon the cooling capacity needed,
in BTU/hour. Equipment manufacturers are responsible for designing
equipment below a maximum charge size consistent with the intended
cooling capacity. This will allow the manufacturer, who is better
positioned than the consumer, to address these challenges. Placing the
responsibility on the manufacturer to design equipment that restricts
the maximum refrigerant charge based upon the cooling capacity needed
also provides a better means for EPA to ensure compliance with the use
conditions, and thus to ensure that the risk to human health will not
be greater than that posed by other available substitutes. We believe
that these requirements, in combination with the other use conditions
and commonly found informational materials, provide sufficient
safeguards against instances of consumers selecting inappropriately-
sized equipment.
    EPA has based its charge limits upon appropriate capacity needs for
an area to be cooled and the requirements for refrigerant charge
relative to room size in Appendix F of UL 484, discussed above. A
document in the docket describes this relationship in tables in a
spreadsheet (EPA, 2015). The charge limits for each refrigerant by
equipment type and mounting location are as follows:

                                                                                Table 2--Window AC Units *
                                                                   [Maximum charge size by unit capacity and refrigerant used]
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Charge size in kg (by associated capacity in BTU/hr)
                            Refrigerant                            -----------------------------------------------------------------------------------------------------------------------------
                                                                     5,000    6,000    7,000    8,000    9,000    10,000   12,000   14,000   18,000   21,000   23,000   24,000   30,000   34,000
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
R-32..............................................................     1.73     2.12     2.74     3.00     3.24     3.47     3.68     4.07     4.59     5.48     6.01     6.49     6.72     7.76
R-290.............................................................     0.13     0.16     0.20     0.22     0.24     0.26     0.27     0.30     0.34     0.40     0.44     0.48     0.50     0.57
R-441A............................................................     0.14     0.17     0.22     0.24     0.26     0.28     0.30     0.33     0.37     0.44     0.49     0.53     0.54     0.63
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* Assumes the evaporator is at least 1 m, but not more than 1.8 m, above the floor. Cooling capacities between those in the table are to be linearly interpolated between the next smaller and
  larger capacities listed in the table.

                                                                      Table 3--Packaged Terminal AC Units and Heat Pumps *
                                                                   [Maximum charge size by unit capacity and refrigerant used]
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Charge size in kg (by associated capacity in BTU/hr)
                            Refrigerant                            -----------------------------------------------------------------------------------------------------------------------------
                                                                     5,000    6,000    7,000    8,000    9,000    10,000   12,000   14,000   18,000   21,000   23,000   24,000   30,000   34,000
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
R-32..............................................................     1.04     1.27     1.65     1.80     1.95     2.08     2.21     2.44     2.75     3.29     3.60     3.89     4.03     4.65
R-290.............................................................     0.08     0.09     0.12     0.13     0.14     0.15     0.16     0.18     0.20     0.24     0.27     0.29     0.30     0.34
R-441A............................................................     0.08     0.10     0.13     0.15     0.16     0.17     0.18     0.20     0.22     0.27     0.29     0.32     0.33     0.38
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* Assumes the evaporator is at least 0.6 m, but not more than 1.0 m, above the floor. Cooling capacities between those in the table are to be linearly interpolated between the next smaller and
  larger capacities listed in the table.

                                                           Table 4--Wall-Mounted AC Units * With Compressor 1.8 m Above Floor Level *
                                                                   [Maximum charge size by unit capacity and refrigerant used]
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Charge size in kg (by associated capacity in BTU/hr)
                            Refrigerant                            -----------------------------------------------------------------------------------------------------------------------------
                                                                     5,000    6,000    7,000    8,000    9,000    10,000   12,000   14,000   18,000   21,000   23,000   24,000   30,000   34,000
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
R-32..............................................................     3.12     3.82     4.94     5.41     5.84     6.24     6.62     7.32     7.96     7.96     7.96     7.96     7.96     7.96
R-290.............................................................     0.23     0.28     0.36     0.40     0.43     0.46     0.49     0.54     0.61     0.73     0.80     0.86     0.89     1.00
R-441A............................................................     0.25     0.31     0.40     0.44     0.47     0.51     0.54     0.59     0.67     0.80     0.88     0.95     0.98     1.00
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* Assumes the evaporator is at least 1.8 m, but not more than 2.2 m, above the floor. Cooling capacities between those in the table are to be linearly interpolated between the next smaller and
  larger capacities listed in the table.

                                                                               Table 5--Ceiling-Mounted AC Units *
                                                                   [Maximum charge size by unit capacity and refrigerant used]
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Charge size in kg (by associated capacity in BTU/hr)
                            Refrigerant                            -----------------------------------------------------------------------------------------------------------------------------
                                                                     5,000    6,000    7,000    8,000    9,000    10,000   12,000   14,000   18,000   21,000   23,000   24,000   30,000   34,000
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
R-32..............................................................     3.82     4.67     6.03     6.61     7.14     7.63     7.96     7.96     7.96     7.96     7.96     7.96     7.96     7.96
R-290.............................................................     0.28     0.34     0.44     0.49     0.53     0.56     0.60     0.66     0.74     0.89     0.97     1.00     1.00     1.00
R-441A............................................................     0.31     0.38     0.49     0.54     0.58     0.62     0.66     0.73     0.82     0.98     1.00     1.00     1.00     1.00
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* Assumes the evaporator is at least 2.2 m above the floor. Cooling capacities between those in the table are to be linearly interpolated between the next smaller and larger capacities listed
  in the table.

                                                                                Table 6--Portable Room AC Units *
                                                                   [Maximum charge size by unit capacity and refrigerant used]
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Charge size in kg (by associated capacity in BTU/hr)
                            Refrigerant                            -----------------------------------------------------------------------------------------------------------------------------
                                                                     5,000    6,000    7,000    8,000    9,000    10,000   12,000   14,000   18,000   21,000   23,000   24,000   30,000   34,000
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
R-32..............................................................     1.56     2.35     2.45     2.45     2.45     2.45     2.45     2.45     2.45     2.45     2.45     2.45     2.45     2.45
R-290.............................................................     0.19     0.29     0.30     0.30     0.30     0.30     0.30     0.30     0.30     0.30     0.30     0.30     0.30     0.30
R-441A............................................................     0.21     0.31     0.33     0.33     0.33     0.33     0.33     0.33     0.33     0.33     0.33     0.33     0.33     0.33
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* Assumes equipment meeting UL 484 requirements for non-fixed equipment. Cooling capacities between those in the table are to be linearly interpolated between the next smaller and larger
  capacities listed in the table.

    In cases where the rated capacity exceeds the maximum shown on the
table, the maximum charge size in the table for that refrigerant
applies. In cases where the normal rated capacity lies between two
values listed next to each other in the table, the maximum charge size
should be determined based on a linear interpolation between the two
respective charge sizes. We assume that room air conditioners will be
at least 5,000 BTU/hr in capacity; this corresponds to cooling a floor
area of roughly 100 square feet or 9.3 m\2\ and it is the lowest value
observed at a popular retailer's Web site (www.homedepot.com).
4. Color-Coded Hoses and Piping
    Equipment must have distinguishing color-coded hoses and piping to
indicate use of a flammable refrigerant. This will help alert
technicians immediately to the use of a flammable refrigerant, thereby
reducing the risk of using sparking equipment or otherwise having an
ignition source nearby. The AC and refrigeration industry currently
uses distinguishing colors as a means of identifying different
refrigerants in containers, and so this approach is consistent with
industry practice. 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, no industry standard exists for color-coded hoses
or pipes for ethane, HFC-32, isobutane, propane, or R-441A. The final
use condition requires all such refrigerator tubing to be colored red
PMS #185 to match the red band displayed on the container of flammable
refrigerants under the Air Conditioning, Heating and Refrigeration
Institute (AHRI) Guideline ``N'' 2012, ``2012 Guideline for Assignment
of Refrigerant Container Colors.''
    A cost-effective alternative to painting or dying the hose or pipe
would be to instead add a colored plastic sleeve or cap to the service
tube that is the same red color (PMS #185). The sleeve could also be
boldly marked with a graphic to indicate that the refrigerant is
flammable. The colored plastic sleeve or cap would have to be installed
in such a way as to require that it be forcibly removed in order to
access the service tube. This would alert 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.
EPA is also concerned with ensuring adequate notification of the
presence of flammable refrigerants for personnel disposing of
appliances containing flammable refrigerants.
    EPA believes the use of color-coded hoses or piping (including the
use of sleeves), as well as the use of warning labels discussed below,
is reasonable and consistent with other general industry practices.
This approach is the same as that adopted in our previous rule on
flammable refrigerants (December 20, 2011, at 76 FR 78832).
5. Labeling
    As a use condition, EPA is requiring labeling of new household and
retail refrigerators and freezers, vending machines, non-mechanical
heat transfer equipment, very low temperature refrigeration equipment,
and room air conditioners that are designed to use one of the
refrigerants subject to the acceptability determinations in this
action. EPA is requiring that the warning labels on the equipment
contain letters at least \1/4\ inch high, and be permanently affixed to
the equipment. Warning label language requirements are found in Section
III.A of this rule, ``Listing decisions: substitutes and end-uses,'' as
well as in the regulatory text. The warning label language is similar
to or exactly the same as that required in the following UL standards:
UL 250 in Section SA6.1 for household refrigerators and freezers; UL
541 in Section SA6.1 for vending machines; UL 471 in Section SB6.1 for
commercial refrigerators and freezers; and UL 484 in Section SA6.1 for
room AC units.
    EPA believes that it would be difficult to see warning labels with
the minimum lettering height requirement of \1/8\ inch provided in
these UL standards. Therefore, consistent with the use conditions in
our previous hydrocarbon refrigerants rule (December 20, 2011 at 76 FR
78832), 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, and emergency first responders to view the warning
labels. We understand that UL is considering revising its standards to
be consistent with this requirement.

D. Venting Prohibition

1. What are the statutory requirements concerning venting, release, or
disposal of refrigerants and refrigerant substitutes under section 608
of the CAA?
    The statutory requirements concerning venting, release, or disposal
of refrigerants and refrigerant substitutes are under Section 608 of
the CAA. Section 608 of the Act as amended, titled National Recycling
and Emission Reduction Program, requires EPA to establish regulations
governing the use and disposal of ODS used as refrigerants, such as
certain CFCs and HCFCs, during the service, repair, or disposal of
appliances and industrial process refrigeration (IPR). EPA's authority
to promulgate the regulatory revisions in this action is based in part
on Section 608 of the CAA. Section 608(c)(1) provides that it is
unlawful for any person, in the course of maintaining, servicing,
repairing, or disposing of an appliance (or IPR), to knowingly vent, or
otherwise knowingly release or dispose of, any class I or class II
substance used as a refrigerant in that appliance (or IPR) in a manner
which permits the ODS to enter the environment.
    Section 608(c)(1) further exempts from this self-effectuating
prohibition de minimis releases associated with good faith attempts to
recapture and recycle or safely dispose of such a substance. EPA, as
set forth in its regulations, interprets releases to meet the criteria
for exempted de minimis releases if they occur when the recycling and
recovery requirements of regulations promulgated under sections 608 and
609 are followed. 40 CFR 82.154(a)(2).
    Section 608(c)(2) extends the prohibition in Section 608(c)(1) to
knowingly venting or otherwise knowingly releasing or disposing of any
refrigerant substitute for class I or class II substances by any person
maintaining, servicing, repairing, or disposing of appliances or IPR.
This prohibition applies to any substitute unless the Administrator
determines that such venting, releasing, or disposing does not pose a
threat to the environment. Thus, section 608(c) provides EPA authority
to promulgate regulations to interpret, implement, and enforce this
prohibition on venting, releasing, or disposing of class I or class II
substances and their refrigerant substitutes, which we refer to as the
``venting prohibition'' in this action. EPA's authority under Section
608(c) includes authority to implement Section 608(c)(2) by exempting
certain substitutes for class I or class II substances from the venting
prohibition when the Administrator determines that such venting,
release, or disposal does not pose a threat to the environment.
2. What are EPA's regulations concerning venting, releasing, or
disposing of refrigerant substitutes?
    Regulations promulgated under Section 608 of the Act, published on
May 14, 1993 (58 FR 28660), established a recycling program for ozone-
depleting refrigerants recovered during the servicing and maintenance
of refrigeration and AC appliances. In the same 1993 rule, EPA also
promulgated regulations implementing the Section 608(c) prohibition on
knowingly venting, releasing, or disposing of class I or class II
controlled substances. These regulations were designed to substantially
reduce the use and emissions of ozone-depleting refrigerants.
    EPA issued a final rule on March 12, 2004, at 69 FR 11946, and a
second rule on April 13, 2005, at 70 FR 19273, clarifying how the
venting prohibition in Section 608(c) applies to substitutes for CFC
and HCFC refrigerants (e.g., HFCs and perfluorocarbons (PFCs)) during
the maintenance, service, repair, or disposal of appliances. These
regulations are codified at 40 CFR part 82, subpart F. In relevant
part, they provide that no person maintaining, servicing, repairing, or
disposing of appliances may knowingly vent or otherwise release into
the environment any refrigerant or substitute from such appliances,
with the exception of the following substitutes in the following end-
uses, effective June 23, 2014:
    (A) Isobutane and R-441A in household refrigerators, freezers, and
combination refrigerators and freezers; or
    (B) Propane in retail food refrigerators and freezers (stand-alone
units only).
    As explained in an earlier EPA rulemaking concerning refrigerant
substitutes, EPA has not promulgated regulations requiring
certification of refrigerant recycling/recovery equipment intended for
use with substitutes to date (70 FR 19275; April 13, 2005). However, as
EPA noted, the lack of a current regulatory provision should not be
considered as an exemption from the venting prohibition for substitutes
that are not expressly exempted in Section 82.154(a) (id.). EPA has
also noted that, in accordance with Section 608(c) of the Act, the
regulatory prohibition at Section 82.154(a) reflects the statutory
references to de minimis releases of substitutes as they pertain to
good faith attempts to recover and recycle or safely dispose of non-
exempted substitutes (id.).
    On May 23, 2014, at 79 FR 29682, EPA exempted from the venting
prohibition three hydrocarbon refrigerant substitutes listed as
acceptable, subject to use conditions, in the specified end-uses:
isobutane and R-441A, as refrigerant substitutes in household
refrigerators, freezers, and combination refrigerators and freezers;
and propane as a refrigerant substitute in retail food refrigerators
and freezers (stand-alone units only). That rule does not apply to
blends of hydrocarbons with other refrigerants or containing any amount
of any CFC, HCFC, HFC, or PFC.
    In that action, EPA determined that for the purposes of CAA Section
608(c)(2), the venting, release, or disposal of such hydrocarbon
refrigerant substitutes in the specified end-uses does not pose a
threat to the environment, considering both the inherent
characteristics of these substances and the limited quantities used in
the relevant applications. EPA further concluded that other
authorities, controls, or practices that apply to such refrigerant
substitutes help to mitigate environmental risk from the release of
those three hydrocarbon refrigerant substitutes. For example, state and
local air quality agencies may include VOC emissions reduction
strategies in State Implementation Plans (SIPs) developed to meet and
maintain the NAAQS that would apply to hydrocarbon refrigerants.
3. What is EPA requiring regarding venting, release, or disposal of
refrigerant substitutes, other than hydrocarbons, included in this
action?
    This rule regulates the use of HFC-32 in room AC units. All HFCs
are currently subject to the venting prohibition. EPA is not extending
the exemption to the venting prohibition in this action to HFC-32 or
any refrigerant blends that contain HFC-32 or any other HFC. Further,
the exemption to the venting prohibition in this action does not extend
to blends containing hydrocarbons with other types of compounds, e.g.,
blends of HFCs and hydrocarbons. Such refrigerant substitutes are still
subject to the statutory and regulatory venting prohibition.
4. What is EPA's determination regarding whether venting of
hydrocarbons listed as acceptable, subject to use conditions, in the
end-uses in this action poses a threat to the environment?
    For purposes of Section 608(c)(2) of the CAA, EPA considers two
factors in determining whether or not venting, release, or disposal of
a refrigerant

substitute during the maintenance, servicing, repairing, or disposing
of appliances poses a threat to the environment. See 69 FR 11948 (March
12, 2004); 79 FR 29682 (May 23, 2014). First, EPA analyzes the threat
to the environment due to inherent characteristics of the refrigerant
substitute, such as GWP. Second, EPA determines whether and to what
extent venting, release, or disposal actually takes place during the
maintenance, servicing, repairing, or disposing of appliances, and to
what extent such actions are controlled by other authorities,
regulations, or practices. To the extent that such releases are
adequately controlled by other authorities, EPA defers to those
authorities. In addition, we considered the public comments we received
on the proposed rule on this topic. We received no comments that caused
us to change our proposed conclusion that venting, release, or disposal
of the specified refrigerant substitutes in the specified end-uses does
not pose a threat to the environment. Therefore, we are finalizing this
portion of the rule as originally proposed.
i. Potential environmental impacts
    EPA has evaluated the potential environmental impacts of releasing
into the environment the four hydrocarbon refrigerant substitutes that
we are listing under the SNAP program as acceptable, subject to use
conditions, in the specified end-uses--i.e., ethane in very low
temperature refrigeration equipment and equipment for non-mechanical
heat transfer; isobutane in retail food refrigerators and freezers
(stand-alone equipment only) and vending machines; propane in household
refrigerators and freezers and combination refrigerators and freezers,
vending machines, and self-contained room air conditioners for
residential and light commercial air conditioning and heat pumps; and
R-441A in retail food refrigerators and freezers (stand-alone equipment
only), vending machines, and self-contained room air conditioners for
residential and light commercial air conditioning and heat pumps. In
particular, we assessed the potential impact of the release of
additional hydrocarbons on local air quality and their ability to
decompose in the atmosphere, their ODP, their GWPs, and potential
impacts on ecosystems.
    As explained in Section IV.A, ``Effects on the environment,'' the
ODP of these hydrocarbons is zero, the GWPs are less than 10, and
effects on aquatic life are expected to be small. As to potential
effects on local air quality, based on the analysis and modeling
results described in the proposal and in Section IV.A of this preamble,
EPA concludes that the four hydrocarbon refrigerant substitutes listed
in this action for their specific end-uses are expected to have little
impact on local air quality.
    In addition, when examining all hydrocarbon substitute refrigerants
in those uses for which UL currently has standards in place, for which
the SNAP program has already listed the uses as acceptable subject to
use conditions, or for which the SNAP program is reviewing a
submission, including those in this rule, we found that even if all the
refrigerant in appliances in end-uses addressed in this rule were to be
emitted, there would be a worst-case impact of less than 0.15 ppb for
ground-level ozone in the Los Angeles area. In light of its evaluation
of potential environmental impacts, EPA concludes that the four
hydrocarbon refrigerant substitutes in the end-uses at issue in this
rule are not expected to pose a threat to the environment on the basis
of the inherent characteristics of these substances and the limited
quantities used in the relevant end-uses (ICF, 2014a).
ii. Toxicity and Flammability
    As discussed in Sections IV.B, ``Flammability'' and IV.C.,
``Toxicity and asphyxiation,'' EPA's SNAP program evaluated the
flammability and toxicity risks from the substitute refrigerants in
this rule. EPA is providing some of that information in this section as
well.
    Hydrocarbons, including ethane, propane, isobutane and the
hydrocarbon blend R-441A, are classified as A3 refrigerants by ASHRAE
Standard 34-2010, indicating that they have low toxicity and high
flammability. Hydrocarbons in this rule have LFLs ranging from 1.8% to
3.0% (18,000 ppm to 30,000 ppm). To address flammability risks, this
rule contains recommendations for their safe use (see Section III.E.,
``Recommendations for the safe use of flammable substitute
refrigerants'' below) and specified use conditions. The SNAP program's
analysis suggests that the use conditions in this rule mitigate
flammability risks.
    Like most refrigerants, at high concentrations hydrocarbons can
displace oxygen and cause asphyxiation. Various industry and regulatory
standards exist to address asphyxiation and toxicity risks. The SNAP
program's analysis of asphyxiation and toxicity risks suggests that the
use conditions in this rule mitigate asphyxiation and toxicity risks.
Furthermore, the Agency believes that the flammability risks and
occupational exposures to hydrocarbons are adequately regulated by OSHA
and building and fire codes at a local and national level.
iii. Authorities, Controls, or Practices
    EPA believes that existing authorities, controls, or practices will
mitigate environmental risk from the release of these hydrocarbon
refrigerant substitutes. Analyses performed for both this rule and the
SNAP rules issued in 1994 and 2011 (March 17, 1994, at 59 FR 13044 and
December 20, 2011, at 76 FR 38832, respectively) indicate that existing
regulatory requirements and industry practices designed to limit and
control these substances adequately control the emission of the
hydrocarbon refrigerant substitutes listed in this action. As explained
below, EPA concludes that the limits and controls under other
authorities, regulations, or practices adequately control the release
of and exposure to the four hydrocarbon refrigerant substitutes and
mitigate risks from any possible release.
    As mentioned above, the determination of whether venting, release,
or disposal of a substitute refrigerant poses a threat to the
environment includes considering the extent that such venting, release,
or disposal is adequately controlled by other authorities, regulations,
or practices. As such, this conclusion is another part of the
determination that the venting, release, or disposal of these four
hydrocarbon refrigerant substitutes, in the specified end-uses and
subject to the use conditions in this action, does not pose a threat to
the environment.
    Industry service practices and OSHA standards and guidelines that
address hydrocarbon refrigeration equipment, include monitoring
efforts, engineering controls, and operating procedures. OSHA
requirements that apply during servicing include continuous monitoring
of explosive gas concentrations and oxygen levels. In general,
hydrocarbon emissions from refrigeration systems are likely to be
significantly smaller than those emanating from the industrial process
and storage systems, which are controlled for safety reasons. In the
SNAP listings in Section III.A, ``Listing decisions: substitutes and
end-uses,'' we note that the amount of refrigerant substitute from a
refrigerant loop is limited: 57 g for household refrigerators and
freezers; 150 g for commercial stand-alone refrigerators and freezers,
very low temperature refrigeration equipment non-mechanical heat
transfer equipment, and vending machines; with larger but still limited
charges for room

air conditioners (1,000 g for hydrocarbon refrigerants). This indicates
that hydrocarbon emissions from such uses are likely to be relatively
small.
    Hydrocarbons that are also VOC may be regulated as VOC under
sections of the CAA that address nonattainment, attainment, and
maintenance of the NAAQS for ground-level ozone, including those
sections addressing development of SIPs and those addressing permitting
of VOC sources.
    The release and/or disposal of many refrigerant substitutes,
including hydrocarbons, are controlled by other authorities including
those established by OSHA and the National Institute for Occupational
Safety and Health's (NIOSH) guidelines, various standards, and state
and local building codes. To the extent that release during
maintaining, repairing, servicing, or disposing of appliances is
controlled by regulations and standards of other authorities, EPA
believes these practices and controls for the use of hydrocarbons are
sufficiently protective. These practices and controls mitigate the risk
to the environment that may be posed by the venting, release, or
disposal of these four hydrocarbon refrigerants during the maintaining,
servicing, repairing, or disposing of appliances.
    EPA is now aware of equipment that can be used to recover
hydrocarbon refrigerants. While there are no relevant U.S. standards
for such recovery equipment, to the extent that these hydrocarbons are
recovered rather than vented in specific end-uses and equipment, EPA
recommends the use of recovery equipment designed specifically for
flammable refrigerants in accordance with applicable safe handling
practices.
iv. Conclusion
    EPA has reviewed the potential environmental impacts of the four
hydrocarbon refrigerant substitutes in the end-uses in this action, as
well as the authorities, controls, and practices in place for those
hydrocarbon refrigerant substitutes. EPA also considered the public
comments on the proposal for this action. Based on this review, EPA
concludes that these four hydrocarbon refrigerant substitutes in these
end-uses and subject to these use conditions are not expected to pose a
threat to the environment based on the inherent characteristics of
these substances and the limited quantities used in the relevant
applications. EPA additionally concludes that existing authorities,
controls, or practices help mitigate environmental risk from the
release of those four hydrocarbons in these end-uses and subject to
these use conditions. In light of these conclusions and those described
or identified above in this section, EPA is determining that based on
current evidence and risk analyses, the venting, release, or disposal
of these four hydrocarbon refrigerant substitutes in these end-uses,
and during the maintenance, servicing, repairing or disposing of the
relevant appliances or equipment, does not pose a threat to the
environment. Furthermore, EPA is exempting from the venting prohibition
at 40 CFR 82.154(a)(1) these additional end-uses for which these
hydrocarbons are being listed as acceptable, subject to use conditions,
under the SNAP program.
    This exemption does not mean that hydrocarbons can be vented in all
situations at this time. Hydrocarbons being recovered, vented, or
otherwise disposed of from commercial and industrial appliances are
likely to be hazardous waste under the Resource Conservation and
Recovery Act (RCRA) (see 40 CFR parts 261-270). As discussed in the
final rule allowing for the venting of isobutane and R-441A as
refrigerant substitutes in household refrigerators, freezers, and
combination refrigerators and freezers, and propane as a refrigerant
substitute in retail food refrigerators and freezers (stand-alone units
only), incidental releases may occur during the maintenance, service,
and repair of appliances. Nor would this activity be subject to RCRA
requirements for the disposal of hazardous waste, as such releases
would not constitute disposal of the refrigerant charge as a solid
waste, per se. Disposal of hydrocarbons from household appliances is
also not considered disposal of a hazardous waste under the existing
RCRA regulations and could be vented under the household hazardous
waste exemption. See 40 CFR 261.4(b)(1). However, for commercial and
industrial appliances, it is likely that flammable hydrocarbon
refrigerant substitutes would be classified as hazardous waste and
would need to be managed as hazardous waste under the RCRA regulations
(40 CFR parts 261-270).

E. Recommendations for the Safe use of Flammable Substitute
Refrigerants

    EPA recommends that only technicians specifically trained in
handling flammable refrigerant substitutes dispose of or service
refrigeration and AC equipment containing these substances. Technicians
should know how to minimize the risk of fire and the procedures for
using flammable refrigerant substitutes safely. Releases of large
quantities of flammable refrigerants during servicing and
manufacturing, especially in enclosed, poorly ventilated spaces or in
areas where large amounts of refrigerant are stored, could cause an
explosion if an ignition source exists nearby. For these reasons, it is
important that only properly trained technicians handle flammable
refrigerant substitutes when maintaining, servicing, repairing, or
disposing of household and retail food refrigerators and freezers, very
low temperature freezers, non-mechanical heat transfer equipment (e.g.,
thermosiphons), and room air conditioners. In addition, EPA recommends
that if hydrocarbon refrigerant substitutes are vented, released, or
disposed of (rather than recovered), as would be allowed in most of the
specified end-uses in this rule, the release should be in a well-
ventilated area, such as outside of a building.
    We are aware that at least two organizations, Refrigeration Service
Engineers Society (RSES) and the ESCO Institute, have developed
technician training programs in collaboration with refrigeration
equipment manufacturers and users that address safe use of flammable
refrigerant substitutes. In addition, EPA has reviewed several training
programs provided as part of SNAP submissions from persons interested
in flammable refrigerant substitutes. The agency intends to update the
test bank for technician certification under Section 608 of the CAA as
we have done previously, and will consider including additional
questions on flammable refrigerants. By adding such questions to the
test bank, EPA would supplement but would not replace technician
training programs currently provided by non-government entities. EPA
will seek additional information and guidance on how best to
incorporate this content through a separate process outside of this
final rule.

IV. What criteria did EPA consider in determining whether to list the
substitutes as acceptable and in determining the use conditions, and
how does EPA consider those criteria?

    As discussed above, Section 612(c) of the CAA directs EPA to
publish lists of acceptable substitutes for specific uses. EPA
considers whether the risks to human health and the environment of a
substitute poses less risk than that posed by other substitutes that
are currently or potentially available. EPA also considers whether the
substitute for class I and class II ODS poses lower overall risk to
human health and the

environment as compared to the ODS historically used in the end-use.
The criteria we review are listed at 40 CFR 82.180(a)(7). These
criteria are: (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.
    EPA evaluated each of the criteria for each substitute in each end-
use in this action and then for each substitute, we considered overall
risk to human health and the environment in comparison to other
available or potentially available alternatives in the same end-uses.
Based on our evaluations, we may reach different conclusions about the
same substitute in different end-uses, because of different risk
profiles (e.g., different exposure levels and usage patterns) and
different sets of available or potentially available substitutes for
each end-use.
    As we have noted previously, environmental and human health
exposures can vary significantly depending on the particular
application of a substitute--and over time, information available
regarding a substitute can change. See 78 FR at 29035 (May 17, 2013).
SNAP's comparative risk framework does not imply fundamental tradeoffs
with respect to different types of risk, either to the environment or
to human health. For example, in this rule, we considered all the human
health and environmental criteria, and addressed the potential risks
from flammability by imposing use conditions, rather than deciding that
other criteria were more important. EPA recognizes that during the more
than two-decade history of the SNAP program, new information about
alternatives already found acceptable has become available and new
alternatives have emerged. To the extent possible, for each SNAP
review, EPA considers information current at the time of the review
which has improved our understanding of the risk factors for the
environment and human health in the context of the available or
potentially available alternatives for a given use.

A. Effects on the Environment

    The SNAP program considers a number of environmental criteria when
evaluating substitutes: ODP; climate effects, primarily based on GWP;
local air quality impacts, particularly potential impacts on smog
formation from emissions of VOC; and ecosystem effects, particularly
from negative impacts on aquatic life. These and other environmental
and health risks are discussed below.
    The ODP is the ratio of the impact on stratospheric ozone of a
chemical compared to the impact of an identical mass of CFC-11. Thus,
the ODP of CFC-11 is defined to be one (1.0). Other ODS have ODPs that
range from 0.01 to ten (10.0).
    All refrigerant substitutes in this final rule have an ODP of zero,
lower than the ODP of ozone depleting refrigerants such as CFC-12 (ODP
= 1.0); HCFC-22 (ODP = 0.055); R-13B1 (ODP = 10) and R-502 (ODP =
0.334). The most commonly used substitutes in the end-uses addressed in
this final rule also have an ODP of zero (e.g., R-404A, R-134a, R-410A,
and R-407C).\13\ Some less common alternatives for these end-uses, such
as R-401A, R-414A, and other blends containing HCFC-22 or HCFC-
142b,\14\ have ODPs ranging from 0.01 to 0.047. Thus, the refrigerant
substitutes in this rule have ODPs lower than or identical to the ODPs
of other available substitutes and of ODS historically used in the end-
uses addressed in this rule.
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    \13\ We assume that substitutes containing no chlorine, bromine,
or iodine have an ODP of zero.
    \14\ Under EPA's phaseout regulations, virgin HCFC-22, HCFC-
142b, and blends containing HCFC-22 or HCFC-142b may only be used to
service existing appliances. Consequently, virgin HCFC-22, HCFC-142b
and blends containing HCFC-22 or HCFC-142b may not be used to
manufacture new pre-charged appliances or appliance components or to
charge new appliances assembled onsite.
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    The GWP is a means of quantifying the potential integrated climate
forcing of various GHGs relative to carbon dioxide. Each of the
hydrocarbon refrigerants in this final rule has a relatively low 100-
year integrated GWP of less than ten while HFC-32 has a GWP of 675. For
comparison, some other commonly used refrigerants currently listed as
acceptable in retail food refrigeration, vending machines, and
household refrigerators and freezers end-uses are R-134a, R-404A, and
R-407C, with GWPs of about 1,430, 3,920, and 1,770, respectively. In
very low temperature refrigeration, a commonly-used substitute is R-
508B, with a GWP of 13,400. An ODS in this end-use is R-13B1/halon 1301
with a GWP of 7,140. The GWPs of the substitutes in this final rule are
significantly lower than those of other refrigerants currently being
used in the residential and light commercial AC and heat pump end-use,
such as the HFC blend substitute R-410A. In addition, the substitutes
in this rule have lower GWPs than those of ODS in this end-use, CFC-12
(GWP = 10,900); HCFC-22 (GWP = 1,810); and R-502 (GWP = 4,660) (IPCC,
2007).
    As stated above, EPA considers overall risk to human health and the
environment compared to alternatives that are available and potentially
available in a given end-use. Therefore, while the GWP of 675 for HFC-
32 is considered low for the residential and light-commercial AC and
heat pumps end-use, it may not be considered low in other end-uses that
have a larger variety of substitutes with lower GWPs. Among the
acceptable substitutes listed in the residential and light-commercial
AC and heat pumps end-use, only ammonia absorption and the non-vapor
compression technologies evaporative cooling and desiccant cooling have
lower GWPs than the substitutes listed in this final rule in this end-
use.
    The total environmental effects impacts of these refrigerants also
depend upon the energy use of appliances, since the ``indirect'' GHG
emissions associated with electricity consumption typically exceed
those from refrigerants over the full lifecycle of refrigerant-
containing products. (ORNL, 1997). If appliances designed to use
refrigerants listed as acceptable in this final rule are less energy
efficient than the appliances they replace, then it is possible that
these appliances would result in higher lifecycle GHG emissions than
appliances using a higher GWP refrigerant or refrigerant substitute.
Conversely, higher energy efficiency of these appliances would lead to
even lower lifecycle GHG emissions.
    While we have not undertaken a comprehensive assessment of all
sources of GHG emissions associated with substituting ODS and other
commonly used refrigerants with the refrigerants in this final rule, we
note that energy efficiency standards exist for most of the types of
equipment covered here.\15\ Thus, total energy use with the substitute
refrigerants we are finding acceptable in this action can be expected
to be no higher than that required by the standards for those classes
of equipment.\16\ Further, testing

data, peer-reviewed journal articles, and other information provided by
the submitters for these substitute refrigerants indicate that
equipment using these refrigerants is likely to have a higher
coefficient of performance and use less energy than equipment currently
being manufactured that uses the most commonly used refrigerants that
are listed as acceptable under SNAP. This indicates that equipment
using the refrigerants listed will have the same or lower climate
impacts than other available substitutes (Daikin, 2011; A.S. Trust &
Holdings, 2012; A/S Vestfrost, 2012; CHEAA, 2013).
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    \15\ For example, Department of Energy (DOE) standards apply to
portable air conditioners, room air conditioners, PTACs and PTHPs,
household refrigerators and freezers, refrigerated beverage vending
machines, and commercial refrigeration equipment. See https://www1.eere.energy.gov/buildings/appliance_standards/standards_test_procedures.html.
    \16\ Refrigeration or air conditioning equipment in the
applicable covered equipment class would still be subject to DOE's
standards, regardless of the refrigerant that the equipment uses. If
a manufacturer believes that its design is subjected to undue
hardship by DOE's regulations, the manufacturer may petition DOE's
Office of Hearing and Appeals (OHA) for exception relief or
exemption from the standard pursuant to OHA's authority under
Section 504 of the DOE Organization Act (42 U.S.C. 7194), as
implemented at subpart B of 10 CFR part 1003. OHA has the authority
to grant such relief on a case-by-case basis if it determines that a
manufacturer has demonstrated that meeting the standard would cause
hardship, inequity, or unfair distribution of burdens.
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    In addition to global impacts on the atmosphere, EPA evaluated
potential impacts of the substitutes on local air quality. Ethane and
HFC-32 are exempt 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. The other refrigerants, isobutane, propane, and
components of R-441A, including isobutane, n-butane, and propane, are
VOC. Potential emissions of VOC from all substitutes for all end-uses
in the refrigeration and AC sector are addressed by the venting
prohibition under Section 608 of the CAA. Under that prohibition,
refrigerant substitutes (and thus the VOC they contain) may only be
emitted where EPA issues a final determination exempting a refrigerant
substitute from the venting prohibition on the basis that venting,
releasing or disposing of such substance does not pose a threat to the
environment. Based on an analysis described below, EPA estimates that
potential emissions of hydrocarbons if used as refrigerant substitutes
in all end-uses in the refrigeration and AC sector would have little
impact on local air quality, with the possible exception of unsaturated
hydrocarbons such as propylene (ICF, 2014a).
    EPA analyzed a number of scenarios to consider the potential
impacts on local air quality if hydrocarbon refrigerants were used
widely. We used EPA's Vintaging Model to estimate the hydrocarbon
emissions from these scenarios and EPA's Community Multiscale Air
Quality (CMAQ) model to assess their potential incremental
contributions to ground-level ozone concentrations (ICF, 2014a). That
analysis was conservative in that it assumed that the most reactive
hydrocarbon subject to this action--isobutane--was used in all
refrigeration and AC uses even though isobutane was not proposed or
listed as acceptable for use in all refrigeration and AC uses. In
addition, the analysis assumed that all refrigerant used was emitted to
the atmosphere. In that highly conservative scenario, the model
predicted that the maximum increase in the 8-hour average ground-level
ozone concentration would be 0.72 ppb in Los Angeles.
    For further information on the potential impacts of this rule and
other decisions we might make, EPA also performed a less conservative
analysis, looking at a set of end-uses that would be more likely to use
hydrocarbon refrigerants between now and 2030. The analysis assumed use
of hydrocarbon refrigerants in those uses for which UL currently has
standards in place, for which the SNAP program has already listed the
uses as acceptable, subject to use conditions, or for which the SNAP
program is reviewing a submission, including those in this rule.\17\ In
addition, the air quality analysis assumed several different
hydrocarbons \18\ would be used based upon those under review by the
SNAP program in the end-uses for which they were submitted. For
example, we assumed use of propane, R-441A, and another hydrocarbon
refrigerant under review in room air conditioners; and isobutane,
propane, and R-441A in vending machines, stand-alone retail food
refrigeration equipment, and household refrigerators and freezers; but
no use of hydrocarbons in chillers used for AC of large buildings. (For
further information on the specific assumptions, see ICF, 2014a, in the
docket for this rulemaking.)
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