6560-50-P

  FILENAME   \* MERGEFORMAT  EO_12866 SNAP Low GWP Refrigerants
2060-AS04 NPRM 20140508.docx

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 82

[EPA–HQ–OAR–2013–0748; FRL-9906-56-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: Notice of proposed rulemaking.

SUMMARY: Pursuant to the U.S. Environmental Protection Agency’s
Significant New Alternatives Policy program, this action proposes to
list a number of flammable refrigerants as acceptable substitutes,
subject to use conditions, for ozone-depleting substances in several
end-uses: household refrigerators and freezers, stand-alone commercial
refrigerators and freezers, very low temperature refrigeration,
non-mechanical heat transfer, vending machines, and room air
conditioning units. This action also proposes to exempt from Clean Air
Act Section 608’s prohibition on venting, release, or disposal the
hydrocarbon refrigerant substitutes that we are proposing to list in
this action as acceptable subject to use conditions in specific
end-uses. We are proposing this exemption on the basis of current
evidence that their venting, release, or disposal would not pose a
threat to the environment.

DATES: Comments must be received on or before [INSERT DATE 60 DAYS AFTER
PUBLICATION IN FEDERAL REGISTER]. Any party requesting a public hearing
must notify the contact listed below under FOR FURTHER INFORMATION
CONTACT by 5 p.m. Eastern Daylight Time on [INSERT DATE 15 DAYS AFTER
PUBLICATION IN FEDERAL REGISTER]. If a hearing is held, it will take
place on or about [INSERT DATE 30 DAYS AFTER PUBLICATION IN FEDERAL
REGISTER] in Washington, DC and further information will be provided on
EPA’s Stratospheric Ozone Website at www.epa.gov/ozone/snap.

ADDRESSES: Submit your comments, identified by Docket ID No.
EPA–HQ–OAR–2013–0748, by one of the following methods:

•  HYPERLINK www.regulations.gov.  Follow the on-line instructions for
submitting comments.

• E-mail:  HYPERLINK<EMAIL_ADDRESS>\h
<EMAIL_ADDRESS>

• Mail: Air and Radiation Docket, Environmental Protection Agency,
Mail Code 6102T, 1200 Pennsylvania Ave., NW., Washington, DC 20460,
Attention Docket ID No. EPA–HQ–OAR–2013–0748.

• Hand Delivery: EPA Docket Center, (EPA/DC) EPA West, Room 3334, 1301
Constitution Ave., NW., Washington, DC, Attention Docket ID No.
EPA–HQ–OAR–2013–0748. Such deliveries are only accepted during
the Docket’s normal hours of operation, and special arrangements
should be made for deliveries of boxed information.

Instructions: Direct your comments to Docket ID No.
EPA–HQ–OAR–2013–0748. EPA’s policy is that all comments
received will be included in the public docket without change and may be
made available online at  HYPERLINK "http://www.regulations.gov/" \h
www.regulations.gov,  including any personal information provided,
unless the comment includes information claimed to be Confidential
Business Information (CBI) or other information whose disclosure is
restricted by statute. Do not submit information that you consider to be
CBI or otherwise protected through  HYPERLINK
"http://www.regulations.gov/" \h www.regulations.gov  or e-mail. The
HYPERLINK "http://www.regulations.gov/" \h www.regulations.gov  Website
is an “anonymous access” system, which means EPA will not know your
identity or contact information unless you provide it in the body of
your comment. If you send an e-mail comment directly to EPA without
going through  HYPERLINK "http://www.regulations.gov/" \h
www.regulations.gov,  your e-mail address will be automatically captured
and included as part of the comment that is placed in the public docket
and made available on the Internet. If you submit an electronic comment,
EPA recommends that you include your name and other contact information
in the body of your comment and with any disk or CD–ROM you submit. If
EPA cannot read your comment due to technical difficulties and cannot
contact you for clarification, EPA may not be able to consider your
comment. Electronic files should avoid the use of special characters and
any form of encryption, and should be free of any defects or viruses.
For additional instructions on submitting comments, go to Section I.B.
of the SUPPLEMENTARY INFORMATION section of this document.

Docket: All documents in the docket are listed in the  HYPERLINK
"http://www.regulations.gov/" \h www.regulations.gov  index. Although
listed in the index, some information is not publicly available, i.e.,
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  HYPERLINK "http://www.regulations.gov/" \h www.regulations.gov  or
in hard copy at the Air and Radiation Docket, EPA/DC, EPA West, Room
3334, 1301 Constitution Ave., NW. Washington, DC. The Public Reading
Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday,
excluding legal holidays. The telephone number for the Public Reading
Room is (202) 566–1744, and the telephone number for the Air and
Radiation Docket is (202) 566–1742.

FOR FURTHER INFORMATION CONTACT: Margaret Sheppard, Stratospheric
Protection Division, Office of Atmospheric Programs, Mail Code 6205J,
Environmental Protection Agency, 1200 Pennsylvania Ave., NW.,
Washington, DC 20460; telephone number (202) 343–9163; fax number
(202) 343–2338, e-mail address<EMAIL_ADDRESS>Notices and
rulemakings under EPA’s Significant New Alternatives Policy (SNAP)
program are available on EPA’s Stratospheric Ozone Website at
HYPERLINK "http://www.epa.gov/ozone/snap/regs" \h
www.epa.gov/ozone/snap/regs.

SUPPLEMENTARY INFORMATION:

Table of Contents

General Information

Background

Does this action apply to me?

What should I consider as I prepare my comments for EPA?

What acronyms and abbreviations are used in the preamble?

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

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

What is EPA’s regulation implementing section 612?

How do the regulations for the SNAP program work?

Where do I find additional information about the SNAP program?

What substitutes in what end-uses are considered in this proposed rule?

What listing decisions is EPA proposing in this action?

What are ethane, isobutane, propane, HFC-32, R-441A, and the ASHRAE
classifications for refrigerant flammability?

What end-uses are included in EPA’s proposed decision?

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

Effects on the environment

Flammability and fire safety

Toxicity

Why is EPA proposing these specific use conditions?

New equipment only; not intended for use as a retrofit alternative

Standards

Charge size

Color-coded hoses and piping

Labeling

Other options not included

How is EPA proposing to address venting, release, or disposal of the
refrigerant substitutes proposed to be listed under section 608 of the
Clean Air Act?

What are the statutory requirements concerning venting, release, or
disposal of refrigerants and refrigerant substitutes under section 608
of the Clean Air Act?

What are EPA’s regulations concerning venting, releasing or disposing
of refrigerant substitutes?

What revision to the venting prohibition has EPA recently proposed?

What is EPA’s proposed determination regarding whether venting of
hydrocarbons to be listed as acceptable subject to use conditions in the
end-uses proposed in this NPRM poses a threat to the environment?

What is EPA proposing regarding venting, release, or disposal of
refrigerant substitutes, other than hydrocarbons, included in our
proposed decision?

What recommendations does EPA have for safe use of the proposed
flammable substitute refrigerants?

Statutory and Executive Order Reviews

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

Paperwork Reduction Act

Regulatory Flexibility Act

Unfunded Mandates Reform Act

Executive Order 13132: Federalism

Executive Order 13175: Consultation and Coordination with Indian Tribal
Governments

Executive Order 13045: Protection of Children from Environmental Health
and Safety Risks

Executive Order 13211: Actions that Significantly Affect Energy Supply,
Distribution, or Use

National Technology Transfer and Advancement Act

Executive Order 12898: Federal Actions to Address Environmental Justice
in Minority Populations and Low-Income Populations

References

I. General Information

A. Background

This rule lists as acceptable subject to use conditions a number of
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 proposed refrigerants include one hydrofluorocarbon (HFC)
refrigerant—HFC-32—and four hydrocarbon refrigerants—ethane,
isobutane, propane, and R-441A. This proposed rule, if finalized as
proposed, would list one or more of these substitutes as acceptable
subject to use conditions in a number of stationary air-conditioning 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 air conditioning and heat
pumps. The use conditions would 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.

All of the end-uses proposed in this rule are for stationary
refrigeration or air conditioning; EPA previously addressed 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 sufficient information to demonstrate
safe use in that end-use at that time. 40 CFR Part 82, Subpart G,
Appendix B. Some of these risks are unique to motor vehicles. In recent
years, EPA has listed three low global warming potential (GWP)
refrigerants as acceptable subject to use conditions for motor vehicles
(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 motor vehicle air conditioning because EPA has
not taken action to specifically list them as acceptable subject to use
conditions.

This proposed rule responds to a number of SNAP submissions for four
hydrocarbon refrigerants and HFC-32 and also lists some of these
refrigerants as acceptable subject to use conditions in the same
end-uses. Additionally, this action proposes to exempt from Section
608’s prohibition on venting, release, or disposal, the four
hydrocarbon refrigerant substitutes that we are proposing to list 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 that other environmental
regulatory requirements still apply. For example, for those refrigerants
that are volatile organic compounds (VOC) as defined in 40 CFR
50.100(s), i.e., isobutane, propane, and R-441A, 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.

With the exception of HFC-32, the refrigerants proposed 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 air conditioning units such as mini-splits
and portable room air conditioners.

Because hydrocarbon refrigerants have zero ozone depletion potential
(ODP) and very low 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 in the Federal Register 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 found propane acceptable
subject to use conditions in retail food refrigerators and freezers
(stand-alone units only). In this action, EPA is considering isobutane,
propane, and R-441A for different end-uses.

There is interest in use of HFC-32 (difluoromethane, Chemical Abstracts
Service Registry Number [CAS Reg. No.] 75-10-5) in residential air
conditioning systems and heat pumps because it has a GWP of 675, which
is lower than the GWPs of hydrochlorofluorocarbon (HCFC)-22 (1,810) and
most other HFC-based refrigerants (approximately 1,500 to 4,000). 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.

This action proposes to list one or more of these five lower-GWP
refrigerant substitute options as acceptable subject to use conditions
in the end-uses identified previously. This is a regular update to
EPA’s lists of acceptable substitutes through the SNAP program under
the authority of Section 612 of the Clean Air Act.

This action also responds to a call in the Climate Action Plan announced
June 2013 for 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 rule proposes to approve
a number of climate-friendly alternatives for various kinds of
refrigeration and air conditioning equipment, as discussed below. This
is the first listing action EPA has taken since the Climate Action Plan
was issued.

This action, if finalized, would expand the menu of available
climate-friendly alternatives. Many of these alternatives can substitute
both for ozone-depleting substances and for high-GWP HFCs. Using low-GWP
alternatives instead of high-GWP HFCs would reduce the impact of
climate-damaging emissions. Use and emissions of HFCs is rapidly
increasing because they are the primary substitutes for ozone-depleting
substances in many of the largest end-uses, and because use is growing
worldwide, mostly due to increased demand for refrigeration and air
conditioning, particularly in developing countries. 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 and their emissions are projected to
increase significantly over the next several decades, if left
unregulated. In the United States, emissions of HFCs are expected to
double from current levels of 1.5 percent of greenhouse gas emissions to
3 percent by 2020 and nearly triple by 2030.

HFCs are rapidly accumulating 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).

This action proposes to find acceptable, for specific end-uses and
subject to use conditions, several alternatives that have GWPs
significantly lower than both the ozone-depleting substances (ODS) and
HFC substitute refrigerants currently used in those end-uses. For
example, this action, if finalized, would allow the use of isobutane
(R-600a) and the hydrocarbon blend R-441A in stand-alone commercial
refrigerators. The GWPs of these hydrocarbon refrigerants are less than
10, while HFCs typically used in this end-use—HFC-134a and R-404A (a
blend of three HFCs)—have GWPs of 1,430 and approximately 3,920,
respectively. In addition, this action proposes to find propane (R-290)
acceptable for use in household refrigerator-freezers, subject to use
conditions. The GWP of R-290 is 3.3 compared to the GWP of 1430 for
HFC-134a, which is typically used in such equipment at the present time
in the U.S. Finally, this action, if finalized, would allow for the use
of propane, R-441A, and difluoromethane (HFC-32) in stand-alone room air
conditioners. These alternatives have GWPs of 675 or less and could
replace the use of R-410A (a blend of two HFCs), which has a GWP of
approximately 2,090. ODS replaced in the end-uses in this rule include
chlorofluorocarbon (CFC)-12 (ODP 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).

B. Does this action apply to me?

This notice of proposed rulemaking (NPRM) would list the following
flammable refrigerants as acceptable subject to use conditions for use
in specific end-uses within the refrigeration and air conditioning
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 air conditioning equipment addressed in this NPRM
include window AC units; packaged terminal AC units and heat pumps; and
portable room AC units. Types of refrigeration equipment include
stand-alone commercial refrigerators and freezers (retail food
refrigeration), very low temperature freezers, thermosiphons
(non-mechanical transfer equipment), household refrigerators and
freezers, and vending machines.

Table 1 identifies the potential entities that may wish to use ethane,
HFC-32, R-441A, isobutane, propane, and other flammable refrigerants in
these end-uses.

TABLE 1—POTENTIALLY REGULATED ENTITIES BY NORTH AMERICAN INDUSTRIAL
CLASSIFICATION SYSTEM (NAICS) CODE OR SUBSECTOR

Category	NAICS code or subsector	Description of regulated entities

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	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	423620	Household Appliances, Electric Housewares, and Consumer
Electronics Merchant Wholesalers

Industry	423740	Refrigeration Equipment and Supplies Merchant
Wholesalers

This table is not intended to be exhaustive, but rather a guide
regarding entities likely to adopt the substitutes whose use would be
regulated by this proposed 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.

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

Submitting Confidential Business Information (CBI)

Do not submit confidential information to EPA through
www.regulations.gov or e-mail. Clearly mark the part or all of the
information that you claim to be CBI. For CBI information in a disk or
CD-ROM that you mail to EPA, mark the outside of the disk or CD-ROM as
CBI and then identify electronically within the disk or CD-ROM the
specific information that is claimed as CBI. In addition to one complete
version of the comment that includes information claimed as CBI, a copy
of the comment that does not contain the information claimed as CBI must
be submitted for inclusion in the public docket. Information marked as
CBI will not be disclosed except in accordance with procedures set forth
in 40 Code of Federal Regulations (CFR) Part 2.

Tips for preparing your comments

When submitting comments, remember to:

Identify the rulemaking by docket number and other identifying
information (subject heading, Federal Register date, and page number).

Follow directions. The agency may ask you to respond to specific
questions or organize comments by referencing a CFR part or section
number.

Explain why you agree or disagree; suggest alternatives and substitute
language for your requested changes.

Describe any assumptions and provide any technical information and/or
data that you used.

If you estimate potential costs or burdens, explain how you arrived at
your estimate in sufficient detail to allow for it to be reproduced.

Provide specific examples to illustrate your concerns, and suggest
alternatives.

Explain your views as clearly as possible, avoiding the use of profanity
or personal threats.

Make sure to submit your comments by the comment period deadline
identified.

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

AHRI—Air Conditioning, Heating and Refrigeration Institute

ANSI—American National Standards Institute

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 Identification Number

CBI—Confidential Business Information

CFC—chlorofluorocarbon

CFR—Code of Federal Regulations

CMAQ—Community Multiscale Air Quality

DOE—the United States Department of Energy

EO—Executive Order

EPA—the United States Environmental Protection Agency

FR—Federal Register

GHG—greenhouse gas

GWP—global warming potential

HCFC—hydrochlorofluorocarbon

HFC—hydrofluorocarbon

ICF—ICF International, Inc.

ICR—Information Collection Request

IEC—International Electrotechnical Commission

IPCC—Intergovernmental Panel on Climate Change

IPR—industrial process refrigeration

kJ—kilojoule

kPa—kilopascal

lb—pound

LFL—lower flammability limit

MSDS—Material Safety Data Sheet

MVAC—motor vehicle air conditioning

NAAQS—National Ambient Air Quality Standard

NAICS—North American Industrial Classification System

NIOSH—the United States National Institute for Occupational Safety and
Health

NOAEL—No Observed Adverse Effect Level

NPRM—Notice of Proposed Rulemaking

NTTAA—National Technology Transfer and Advancement Act

OEM—original equipment manufacturer

ODP—ozone depletion potential

ODS—ozone-depleting substance

OHA—Office of Hearing and Appeals

OMB—the United States Office of Management and Budget

OSHA—the United States Occupational Safety and Health Administration

PEL—permissible exposure limit

PFC—perfluorocarbon

PMS—Pantone Matching System

ppb—parts per billion

ppm—parts per million

PRA—Paperwork Reduction Act

PTAC—packaged terminal air conditioner

PTHP—packaged terminal heat pump

REL—recommended exposure limit

RFA—Regulatory Flexibility Act

SBA—the United States Small Business Administration

SNAP—Significant New Alternatives Policy

STEL—short term exposure limit

TLV—threshold limit value

TSCA—Toxic Substances Control Act

TWA—time-weighted average

UL—Underwriters Laboratories Inc.

UMRA—Unfunded Mandates Reform Act

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 Clean Air Act (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, halon, carbon
tetrachloride, methyl chloroform, and hydrobromofluorocarbon) or class
II substance (hydrochlorofluorocarbon) 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 air conditioning; 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, 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. 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.

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 (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 restrictions may be used only in
accordance with those restrictions.

	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
(FR). 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 providing 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 are 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 website 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 is
found at: www.epa.gov/ozone/snap/chron.html.

III. What substitutes in what end-uses are considered in this proposed
rule?

What listing decisions is EPA proposing in this action?

In this action, EPA proposes to list the following refrigerants as
acceptable substitutes, subject to use conditions, in the identified
end-uses.

Retail food refrigeration. EPA proposes to list isobutane (also referred
to as R–600a) and the hydrocarbon blend R-441A as acceptable subject
to use conditions as substitutes in retail food refrigeration (new
stand-alone commercial refrigerators and freezers only). EPA proposes
the following use conditions:

The quantity of the substitute refrigerant (i.e., “charge size”)
must not exceed 150 grams (5.29 ounces);

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;

These refrigerants may be used only in stand-alone commercial
refrigerators and freezers that meet all requirements listed in
Supplement SB to the 10th edition of Underwriters Laboratories (UL)
Standard 471, dated November 24, 2010. In cases where the proposed rule
includes requirements more stringent than those of the 10th edition of
UL Standard 471, the appliance must meet the requirements of the rule,
as finalized;

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 applied 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;

The following markings, or the equivalent, must be provided and must be
permanent:

“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.

“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.

“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.

“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.

“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.

han 6.4 mm (1⁄4 inch) high. In UL 471, the markings are required to be
no less than 3.2 mm (1/8 inch) high.

2.  Very low temperature refrigeration and non-mechanical heat transfer.
EPA proposes to list ethane (also referred to as R-170), as acceptable,
subject to use conditions, in very low temperature refrigeration
equipment and in non-mechanical heat transfer, subject to the same use
conditions as described above for isobutane and R-441A in stand-alone
commercial refrigerators and freezers.

3. Household refrigerators and freezers. EPA proposes to list propane
(also referred to as R–290), as acceptable subject to use conditions
as a substitute in household refrigerators and freezers and combination
refrigerator/freezers subject to the following use conditions.

The charge size for any household refrigerator, freezer, or combination
refrigerator and freezer for each circuit using R–290 must not exceed
57 grams (2.01 ounces);

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;

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 the proposed rule includes
requirements more stringent than those of the 10th edition of UL
Standard 250, the appliance must meet the requirements of the final SNAP
listing);

The refrigerator or freezer must have red Pantone Matching System (PMS)
#185 marked pipes, hoses, and other devices through which the
refrigerant passes to indicate the use of a flammable refrigerant;

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. (The
difference between this requirement and clauses SA6.2.1 to SA6.2.5 of UL
Standard 250 is that in UL 250, the markings are required to be no less
than 3.2 mm [1/8 inch] high instead of 6.4 mm [1/4 inch]).

4.  Vending machines. EPA proposes to list R–441A, isobutane and
propane as acceptable substitutes in vending machines, subject to the
same use conditions described above for stand-alone commercial
refrigerators and freezers, except that paragraph iii. would read 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 the 10th edition of UL 471).

Note that 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.

5.  Residential and light commercial air conditioning and heat pumps.
EPA proposes to list propane (also known as R-290), difluoromethane
(also known as HFC-32 or R-32), and R-441A as acceptable subject to use
conditions as substitutes in residential and light commercial air
conditioning for self-contained room air conditioners, including
packaged terminal air conditioners (PTACs) and packaged terminal heat
pumps (PTHPs), window AC units, and portable AC units designed for use
in a single room. EPA proposes the following use conditions:

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;

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 Underwriters Laboratories (UL) Standard 484, “Room Air
Conditioners.” In cases where the final rule includes requirements
more stringent than those of the 8th edition of UL Standard 484, the
appliance must meet the requirements of the final rule in place of the
requirements in the UL Standard;

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 proposing the charge limits in the UL 484 standard as a
requirement, EPA is proposing 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, 2013
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 proposed limits are presented in Tables
3 through 6 below in section V.C, “Charge size,” and in Tables A, B,
C and D of the regulatory text at the end of this document.

The air conditioner 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 applied 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;

The following markings, or the equivalent, must be provided and must be
permanent:

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.”

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.”

 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.”

For portable air conditioners, packaged terminal air conditioners and
packaged terminal heat pumps, on the outside of the product: “WARNING:
Appliance shall be installed, operated and stored in a room with a floor
area larger than “X” m2 (Y ft2).” The value “X” must be
determined using the minimum room size in m2 calculated using Appendix F
of UL 484. The evaporator must remain no higher than 0.6 m above the
floor.

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” m2 (Y ft2).” The value “X” must be
determined using the minimum room size in m2 calculated using Appendix F
of UL 484. The evaporator must remain no higher than 1.06 m above the
floor.

6.4 mm (1⁄4 inch) high. (The difference between this requirement and
clauses SA6.2.1 to SA6.2.5 of UL Standard 484 is that in UL 484, the
markings are required to be no less than 3.2 mm [1/8 inch] high instead
of 6.4 mm [1/4 inch]).

The regulatory text of our proposed decisions appears in tables at the
end of this document. If finalized as proposed, this text would be
codified at 40 CFR Part 82 Subpart G. The proposed regulatory text
contains listing decisions for the end-uses discussed above. 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).

In summary, EPA is proposing to list ethane, isobutane, propane, HFC-32,
and R-441A as acceptable subject to use conditions as substitute
refrigerants in certain refrigeration and air conditioning end-uses. If
this proposal were to become final, it would be 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, as finalized, would be a violation
of CAA section 612 and EPA’s implementing regulations. Both the
equipment manufacturers and the end users should be familiar with these
proposed use conditions and EPA would expect them to comply with any
final use conditions.

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 and a chemical
formula of C2H6. Propane has three carbons and the formula C3H8.
Isobutane has four carbons and the formula C4H10, also written as
CH(CH3)2CH3 to distinguish it from n-butane. The respective Chemical
Abstracts Service Registry Numbers (CAS Reg. Nos.) of ethane, propane,
and isobutane are 74-84-0, 74–98–6, and 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 highly
flammable hydrocarbon blend consisting of 55% propane, 36% n-butane, 6%
isobutane, and 3% ethane by weight. 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 °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
3400 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
BTU/lb), and have a lower flammability limit (LFL) greater than 0.10
kg/m3. Refrigerants within flammability classification 2 may optionally
be designated in the lower flammability subclass “2L” if they have a
maximum burning velocity of 10 cm/s or lower when tested at 23.0 °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/m3 or lower. 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).

Figure 1. Refrigerant Safety Group Classification

Safety Group

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. What end-uses are included in our proposed decision?

1. Household Refrigerators, Freezers, and Combination
Refrigerator/Freezers

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.

2. Retail Food Refrigeration--Stand-Alone Commercial Refrigerators and
Freezers

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. In this proposed rule, we are
considering the use of hydrocarbons only in stand-alone equipment. A
stand-alone appliance is one utilizing 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 proposed rule does not apply to
large commercial refrigeration systems such as, but not limited to,
multiplex direct expansion refrigeration systems typically found in
supermarkets. Such equipment typically requires larger charge sizes than
those considered in this proposed rule. This proposal also does not
apply to walk-in coolers, a type of equipment that typically requires
larger charges than those considered in this proposed rule. EPA has
already listed propane as acceptable subject to use conditions for use
in stand-alone commercial refrigerators and freezers. December 20, 2011,
at 76 FR 78832, codified at Appendix R to Subpart G of 40 CFR Part 82.

3. and 4. Very low temperature refrigeration and non-mechanical heat
transfer equipment.

Very low temperature refrigeration equipment is intended to maintain
temperatures considerably lower than for refrigeration of food—for
example, -80 °C (-170 °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 Underwriters Laboratories, Inc. will
test their equipment for compliance with the UL 471 standard for
commercial refrigeration equipment, which addresses stand-alone
commercial refrigerators and freezers. We are proposing 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 proposal would allow use of ethane in
non-mechanical heat transfer uses, provided that they meet the use
conditions, including the requirements of Supplement B to the UL 471
standard and a charge limit of 150 g.

5. Vending Machines

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). The standard UL 541 applies to vending machines. It contains
a Supplement SA specifically addressing flammable refrigerants that is
very similar to the Supplement SB in the UL 471 standard for commercial
refrigerators and freezers.

6. Residential and Light Commercial Air Conditioning and Heat Pumps

This 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 air conditioning, 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 air conditioning and
heat pumps include:

Central air conditioners, also called unitary air conditioning 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.

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 would be regulated under this rule if it becomes final.

Packaged terminal air conditioners and packaged terminal heat pumps.
These are self-contained units that consist of a separate, un-encased
combination of heating and cooling assemblies mounted through a wall.
These types of units would be regulated under this rule if it becomes
final.

Portable room air conditioners. These are self-contained units used
inside rooms that are designed to be moved easily from room to room,
usually having wheels. They may contain an exhaust hose that can be
placed through a window or door to eject heat to the outside. These
types of units would be regulated under this rule if it becomes final.

Of these types of equipment, window air conditioners, packaged terminal
air conditioners, packaged terminal heat pumps, 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 would result 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.

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

Section 612(c) of the Clean Air Act directs EPA to publish a list of
acceptable replacement substances (“substitutes”) for class I and
class II substances for specific uses. EPA compares the risks to human
health and the environment of a substitute to the risks associated with
other substitutes that are currently or potentially available. EPA also
considers whether the substitute for class I and class II ODS “reduces
the overall risk to human health and the environment” 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
for which we are proposing 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 on 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 noted previously on May 17, 2013, at 78 FR 29035, 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. 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. EPA
recognizes that during the nearly two-decade history of the SNAP
program, new information about alternatives already found acceptable and
new alternatives have emerged. To the extent possible, EPA considers
current information that improves 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.

Effects on the environment

The SNAP program considers a number of environmental criteria when
evaluating substitutes: ozone depletion potential (ODP); climate
effects, primarily based on global warming potential (GWP); local air
quality impacts, particularly potential impacts on smog formation from
emissions of volatile organic compounds (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 CFCs and HCFCs have ODPs
that range from 0.01 to one (1.0).

All refrigerant substitutes in this proposal have an ODP of zero, lower
than the ODP of the ozone depleting substances that they replace:
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 proposal also have an ODP of zero (e.g.,
R–404A, R– 134a, R–410A, and R–407C). Some less common
alternatives for these end-uses, such as R-401A, R-414A and other blends
containing HCFC-22 or HCFC-142b, have ODPs ranging from 0.01 to 0.047.
Thus, the refrigerant substitutes in this proposal have ODPs lower than
or identical to the ODPs of other available substitutes and of the
substances they replace.

The GWP is a means of quantifying the potential integrated climate
forcing of various greenhouse gases relative to carbon dioxide. All of
the hydrocarbon refrigerants in this proposal have a relatively low
100-year integrated GWP of less than ten. HFC-32 has a GWP of 675. For
comparison, some other commonly used, acceptable refrigerants in these
end-uses are R–134a, R–404A, R–407C, and R–410A with GWPs of
about 1,430, 3,920, 1,770, and 2,090, respectively. In very low
temperature refrigeration, a common refrigerant is R-508B, with a GWP of
13,400. The GWPs of the ozone-depleting substances that they replace
are: CFC–12 (GWP = 10,900); HCFC–22 (GWP = 1,810); R-13B1/halon 1301
(GWP = 7,140) and R–502 (GWP = 4,660) (IPCC, 2007). The GWPs of the
substitutes reviewed in this proposal are significantly lower than those
of other refrigerants currently being used in the residential and light
commercial air conditioning and heat pump end-use. As stated above, EPA
considers overall risk to human health and the environment compared to
ODS as well as alternatives that are available and potentially available
in a given end-use. Therefore, the GWP of 675 for HFC-32 may not be
considered low in other end-uses that have a larger variety of options
available with lower GWPs. Among the acceptable substitutes listed in
this end-use, only ammonia absorption and the non-vapor compression
technologies evaporative cooling and desiccant cooling would have lower
GWPs. Given technical limits on the effective use of the non-vapor
compression technologies in different climates and the higher toxicity
of ammonia than of the alternatives proposed here, the proposed
substitutes still reduce risk overall compared to the available and
potentially available substitutes in this end-use.

The GHG 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 using the refrigerants being considered in this proposal 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 proposed refrigerants, we note that for most of the types of
equipment covered here, energy efficiency standards exist. Thus, total
energy use with alternative refrigerants can be expected to be no higher
than that required by the standards for those classes of equipment.
Further, testing data, peer-reviewed journal articles and other
information provided by the submitters for these substitute refrigerants
indicated 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 common ODS and HFC refrigerants
that are listed as acceptable under SNAP. This implies that equipment
that uses the refrigerants proposed to be 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).

In addition to global impacts on the atmosphere, EPA evaluated potential
impacts of the proposed 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 State Implementation
Plans (SIPs) to attain and maintain the national ambient air quality
standards. The other proposed 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 air conditioning 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, as proposed elsewhere in this action (see Section
VI, “How is EPA proposing to address venting, release, or disposal of
the refrigerant substitutes proposed to be listed under section 608 of
the Clean Air Act?” below). EPA estimates that potential emissions of
hydrocarbons when used as refrigerant substitutes in all end-uses in the
refrigeration and air conditioning sector have little impact on local
air quality, with the possible exception of unsaturated hydrocarbons
such as propylene (ICF, 2013a). However, for those refrigerants that are
VOC as defined in 40 CFR 50.100(s), a State could adopt additional
control strategies if necessary for an ozone nonattainment area to
attain the National Ambient Air Quality Standard (NAAQS) for ozone.

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, 2013a). That analysis assumed that the most
reactive hydrocarbon proposed to be acceptable (isobutane) was used in
all refrigeration and air conditioning uses, and that all refrigerant
used was emitted to the atmosphere even though isobutane is not being
proposed as acceptable for use in all refrigeration and air conditioning
uses. In that extreme 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. Further, in the analysis, the additional
ground-level ozone did not result in exceeding the NAAQS where an area
was in compliance without the additional refrigerant emissions. Given
the potential sources of uncertainty in the modeling, the
conservativeness of the assumptions, and the finding that the
incremental VOC emissions from this refrigerant emissions would not
cause any area that otherwise would meet the NAAQS to exceed it, we
believe that the use of isobutane consistent with the use conditions
will not result in significantly greater risk to the environment than
other substitutes that are currently or potentially available. Further,
propane, ethane, and n-butane, the remaining component of R-441A, are
less reactive than isobutane and we reach a similar conclusion for those
refrigerants.

EPA also analyzed the potential impacts of the uses of hydrocarbon
refrigerants proposed to be acceptable under this rule. In this less
conservative analysis, EPA looked 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. In addition, the air quality analysis assumed several
different hydrocarbons 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 air conditioning of large
buildings. (For further information on the specific assumptions, see
ICF, 2013a, in the docket for this rulemaking.) Based on this still
conservative but more probable assessment of refrigerant use, we found
that even if all the refrigerant in appliances in end-uses addressed in
this proposed rule were to be emitted, there would be a worst-case
impact of 0.15 ppb ozone in the Los Angeles area, which is the area with
the highest level of ozone pollution in the United States. In the other
cities examined in the analysis, Houston and Atlanta, impacts were
smaller (no more than 0.03 and 0.01 ppb, respectively) (ICF, 2013a).
These impacts did not cause any areas to exceed the NAAQS that otherwise
would have met the NAAQS without the additional refrigerant emissions.
Because of the relatively low air quality impacts of these refrigerants
if they are released to the atmosphere in limited amounts, EPA believes
that these refrigerants do not have a significantly greater impact on
human health and the environment based on their effects on local air
quality than other refrigerants listed as acceptable in the end-uses
proposed in this rule.

The substitutes in this proposal are all highly volatile. They typically
evaporate or partition to air, rather than contaminating surface waters.
Effects on aquatic life of the substitutes are expected to be small and
pose no greater risk of aquatic or ecosystem effects than those of other
available substitutes for these uses.

Based on EPA’s analysis, the overall environmental risks, including
ODP, GWP, local air quality effects and ecosystem impacts are lower than
or comparable to those of other acceptable substitutes in the same
end-uses.

B. Flammability and fire safety

The flammability risks of the proposed substitutes are of potential
concern because household and retail food refrigerators and freezers and
room AC units have traditionally used refrigerants that are not
flammable. Without appropriate use conditions, the flammability risk
posed by these refrigerants could be higher than non-flammable
refrigerants because individuals may not be aware that their actions
could potentially cause a fire, and existing equipment has not been
designed specifically to minimize flammable risks. In this section, we
discuss the risks posed by the refrigerants considered in this rule and
explain the proposed use conditions we believe are necessary to mitigate
risks to ensure that the overall risk to human health and the
environment posed by these proposed substitutes is not greater than the
overall risk posed by other substitutes in the same end-uses. In
addition, we discuss why the flammability risks have led us to propose
that these substitutes are only acceptable for use in new equipment
specifically designed for these flammable refrigerants.

Due to their flammable nature, ethane, isobutane, propane, HFC-32, and
R-441A could pose a significant safety concern for workers and consumers
in the end-uses addressed in this proposal if they are not handled
correctly. In the presence of an ignition source (e.g., static
electricity spark resulting from closing a door, using a torch during
service, or a short circuit in wiring that controls the motor of a
compressor), an explosion or a fire could occur when the concentration
of refrigerant exceeds its lower flammability limit (LFL). The LFLs of
the proposed substitutes are: ethane—30,000 ppm; HFC-32—139,000 ppm;
isobutane—18,000 ppm; propane—21,000 ppm; and R-441A—20,500 ppm.
Therefore, to use these substitutes safely, it is important to minimize
the presence of potential ignition sources and to reduce the likelihood
that the levels of ethane, HFC-32, isobutane, propane, or R-441A will
exceed the LFL. Under the proposed listing decision, these substitutes
would be acceptable for use only in new equipment (refrigerators,
freezers and air conditioners) specifically designed for the
refrigerant. We expect that the original equipment manufacturers, who
would be storing large quantities of the refrigerant, are familiar with
and use proper safety precautions to minimize the risk of explosion, due
to OSHA and building code requirements. We are proposing to include in
the “Further Information” section of the SNAP listings
recommendations that these facilities be equipped with proper
ventilation systems and be properly designed to reduce possible ignition
sources.

To determine whether flammability would be a concern for manufacturing
and service personnel or for consumers, EPA analyzed a plausible
worst-case scenario to model a catastrophic release of the proposed
refrigerants. The worst-case scenario analysis for each refrigerant
revealed that even if the unit’s full charge is emitted within one
minute, none of these refrigerants reached their respective LFLs of 1.8%
for isobutane, 2.1% for propane, 2.05% for R-441A, or 3.0% for ethane,
provided that the charge sizes were no greater than those specified in
the relevant standard from Underwriters Laboratories (ICF,
2013b,c,d,e,f,g,h,i,j,k). Thus, there would not be an excessive risk of
fire or explosion, even under those worst-case assumptions, so long as
the charge meets the use conditions in this proposed rule. Detailed
analysis of the modeling results are discussed below in the next section
regarding “Toxicity.” EPA also reviewed the submitters’ detailed
assessments of the probability of events that might create a fire and
engineering risk and approaches to avoid sparking from the refrigeration
equipment. Further information on these analyses and EPA’s risk
assessments are available in public docket EPA-HQ-OAR-2013-0748 at
www.regulations.gov. Although the analysis showed no potential for the
released refrigerant from one piece of equipment to reach the LFL,
manufacturing and service personnel or consumers are not familiar with
refrigeration or air conditioning equipment containing a flammable
refrigerant. Therefore, use conditions are necessary to ensure people
handling such equipment are aware that equipment contains a flammable
refrigerant and to ensure safe handling. This allows the flammable
refrigerants to be used without increasing overall risk to human health
and the environment.

C. Toxicity

In evaluating potential toxicity impacts of ethane, HFC-32, isobutane,
propane, and R-441A on human health, EPA considered both occupational
and consumer risks. EPA investigated the risk of asphyxiation and of
exposure to toxic levels of refrigerant for a worst-case scenario and a
typical use scenario for each refrigerant. In the worst-case scenario of
a catastrophic leak, we modeled release of the unit’s full charge
within one minute into a confined space to estimate concentrations that
might result. We considered a conservatively small space appropriate to
each end-use, such as a small convenience store of 244 m3 for retail
food refrigeration, a small galley kitchen of 18 m3 for a household
refrigerator/freezer, or a small bedroom of 41 m3 for a room air
conditioner.

To evaluate toxicity of all five refrigerants, EPA estimated the maximum
time-weighted average (TWA) exposure both for a short-term exposure
scenario, with a 15-minute and 30-minute TWA exposure, and for an 8-hour
time weighted average that would be more typical of occupation exposure
for a technician servicing the equipment. We compared these short-term
and long-term exposure values to relevant industry and government
workplace exposure limits for ethane, HFC-32, isobutane, propane, and
components of R-441A, (including potential impurities in the
substitutes). The modeling results indicate that both the short-term
(15-minute and 30-minute) and long-term (8-hour) worker exposure
concentrations would be below the relevant workplace exposure limits,
such as the Occupational Safety and Health Administration (OSHA)
permissible exposure limit (PEL), the National Institute for
Occupational Safety and Health’s (NIOSH) recommended exposure limit
(REL), the American Conference of Governmental Industrial Hygienists’
(ACGIH) threshold limit value (TLV), or in the case of HFC-32, the
manufacturer’s recommended workplace exposure limit. In some cases
where there was not an established short-term exposure limit (STEL), we
considered information on short-term exposure such as the no observed
adverse effect level (NOAEL) from available toxicity studies or the
National Research Council’s Acute Emergency Guideline Limits (AEGL).
The respective workplace exposure limits we considered for the various
compounds, including components of the refrigerant blend R-441A, are as
follows:

n-Butane, a component in R-441A: 800 ppm REL on 10-hr TWA; 6,900 ppm
AEGL-1 over 30 minutes

Ethane: 1000 ppm TLV on 8-hour TWA

HFC-32: 1000 ppm manufacturer’s exposure guideline on 8-hour TWA; 3000
ppm over 15 minutes

Isobutane: 800 ppm REL on 10-hr TWA; 18,000 ppm NOAEL over 30 minutes

Propane: 1000 ppm PEL on 8-hr TWA; 6,900 ppm AEGL-1 over 30 minutes

For equipment with which consumers might come into contact, such as
retail food refrigerators and freezers, vending machines, household
refrigerators and freezers, and room air conditioners, EPA performed a
consumer exposure analysis. In this analysis, we examined potential
catastrophic release of the entire charge of the substitute in
one-minute under a worst-case scenario. We did not examine exposure to
consumers in very low temperature refrigeration, as equipment for this
end-use would typically be used in the workplace, such as in
laboratories, and not in a home or public space. The analysis was
undertaken to determine the 15-minute or 30-minute TWA exposure levels
for the substitute, which were then compared to the toxicity limits to
assess the risk to consumers.

EPA considered toxicity limits for consumer exposure that reflect a
short-term exposure such as might occur at home or in a store or other
public setting where a member of the general public could be exposed and
then could escape. Specific toxicity limits that we used in our analysis
of consumer exposure include:

n-Butane: 6,900 ppm AEGL-1 over 30 minutes

HFC-32: cardiotoxic NOAEL of 350,000 ppm over 5 minutes

Isobutane: 18,000 ppm NOAEL over 30 minutes

Propane: 6,900 ppm AEGL-1 over 30 minutes

The analysis of consumer exposure assumed that 100 percent of the
unit’s charge would be released over one minute, at which time the
concentration of refrigerant would peak in an enclosed space, and then
steadily decline. Refrigerant concentrations were modeled under two air
change scenarios, believed to represent the baseline of potential flow
rates for a home or other public space, assuming flow rates of 2.5 and
4.5 air changes per hour (ACH) (Sheldon 1989). The highest
concentrations of the refrigerant occur in the lower stratum of the room
when assuming the lower ventilation level of 2.5 ACH. Calculating the
TWA exposure using 2.5 ACH results in a higher concentration than
calculating the TWA exposure using 4.5 ACH. Even under the very
conservative assumptions used in the consumer exposure modeling, the
estimated 15-minute or 30-minute consumer exposures to the proposed
refrigerants are much lower than the relevant toxicity limits and thus
should not pose a toxicity risk any greater than that of other
acceptable refrigerants in the proposed end-uses.

For further information, including EPA’s risk screens and risk
assessments as well as fault tree analyses from the submitters of the
substitutes, see docket number EPA–HQ–OAR–2013-0748 at
www.regulations.gov.

V. Why is EPA proposing these specific use conditions?

EPA is proposing to list ethane, isobutane, propane, HFC-32, and R-441A
as acceptable subject to use conditions in the specified end-uses. EPA
is proposing these uses in new equipment designed and manufactured
specifically to use these alternatives. 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
proposed listings with the 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. We seek
comment on the proposed listing as well as the specific use conditions
discussed below.

A. New equipment only; not intended for use as a retrofit alternative

EPA is proposing that the flammable refrigerants considered in this
proposal be limited to use only in new equipment that has been designed
and manufactured specifically for use with the listed alternative
refrigerant. We are proposing that these substitutes may be used only in
new equipment that is designed to address concerns unique to flammable
refrigerants. 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 without giving timely and adequate notice to EPA
would be in violation of section 612(e) of the CAA and the SNAP
regulations at 40 CFR Part 82, Subpart G. In addition, if the rule is
finalized as proposed, use of these refrigerants in existing equipment
would be in violation of section 612(c) of the CAA and the corresponding
SNAP regulations at 40 CFR Part 82, Subpart G.

B. Standards

EPA is proposing that the flammable refrigerants be used only in
equipment that meets all requirements in the relevant supplements for
flammable refrigerants in certain applicable UL Standards for
refrigeration and air conditioning equipment. Specifically, the
standards cited include UL 471 10th edition for commercial refrigerators
and freezers (including stand-alone freezers for very low temperature
refrigeration), UL 250 10th edition (for household refrigerators and
freezers), UL 541 7th edition for refrigerated vending machines, and UL
484 8th edition for room air conditioners.

UL has tested equipment for flammability risk in both household and
retail food refrigeration. 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
air-conditioning and refrigeration 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), we are proposing to rely on UL standards as those that are most
applicable and recognized by the U.S. market. This proposed approach is
the same as that in our previous rule on flammable refrigerants
(December 20, 2011 at 76 FR 78832).

C. Charge size

EPA is proposing use conditions that limit the amount of refrigerant
allowed in each type of appliance. As before, we believe 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 limit the risk
to workers and consumers since under worst-case scenario analyses, a
leak of the proposed charge sizes did not result in concentrations of
the refrigerant that met or exceeded the LFL, as explained above in
Section IV.B, “Flammability and fire safety.”

EPA is proposing limitations on refrigerant charge size for household
and stand-alone commercial refrigerators and freezers, vending machines,
and room air conditioning units that reflect the UL 250, UL 471, UL 541
and UL 484 standards. As discussed above in paragraph B of this section,
we believe UL standards are most applicable to the U.S. market and offer
requirements developed by a consensus of experts. EPA is proposing a
charge size not to exceed 57 grams (2.01 ounces) for household
refrigerators and freezers, not to exceed 150 grams (5.29 ounces) for
retail food refrigeration in stand-alone units, and not to exceed 150
grams (5.29 ounces) for vending machines. We are proposing a varying
charge size limit for room air conditioning units as discussed below. To
place these quantities in a familiar context, EPA estimates the charge
size of a disposable lighter is equal to 30 grams (1.06 ounces).

 The UL 250 standard for household refrigerators and freezers limits the
amount of refrigerant that may leak to 50 grams (1.76 ounces). EPA is
proposing a charge size of 57 grams (2.01 ounces) to allow for up to 7
grams (0.25 ounces) of refrigerant that might be solubilized in the oil
(and assumed not to leak or immediately vaporize with the refrigerant in
the case of a leak). EPA bases this estimate on information received
from a manufacturer of hydrocarbon-based refrigerator-freezers (see
EPA-HQ-OAR-2013-0748 on www.regulations.gov).

UL standards 541 (retail food refrigeration) and 471 (vending machines)
limit the amount of refrigerant leaked to 150 grams (5.29 ounces).
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 grams (5.29
ounces).

As noted above, EPA is proposing a varying charge size for room air
conditioning units. We are proposing that 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 charge of a fixed room air conditioner based
upon the size of the space where the refrigerant may escape and the
lower flammability limit of the refrigerant. The formula is as follows:

Where,

Mmax is the maximum charge size allowed for the space, in kg,

LFL is the lower flammability limit of the refrigerant in kg/m3,

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 m2.

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. Table 2 below gives examples of room sizes and appropriate
charge sizes for the three refrigerants proposed to be listed for use in
room AC units, assuming a typical height of 1.0 m for a window-mounted
unit.

In addition to the formula mentioned above, UL 484 has a requirement
that the maximum charge for a room air conditioner may not exceed the
amount calculated using the following formula:

Where,

m2 is the maximum charge size allowed, in kg,

26 m3 is a constant, and

LFL is the lower flammability limit of the refrigerant in kg/m3.

That formula sets maximum limits on refrigerant in a room air
conditioner, as shown in Table 2. With the A3 refrigerants, the maximum
value is 1 kg.

Table 2. Maximum refrigerant charge sizes

If you are using this refrigerant…	Then its lower flammability limit
is…	The maximum allowable charge in kg for room air conditioner is…
And the maximum charge, in kg, to use in a room of this size is…

	In % by volume	In kg/m3

1.7 m x 1.7 m x 2.5 m (7.2 m3)

A=2.89 m2	6 ft x 8 ft x 8 ft (384 ft3/ 10.9 m3)

A=4.46 m2	12 ft x 10 ft x 10 ft (1200 ft3/ 34.0 m3)

A=11.15 m2

HFC-32	14.4	0.306	7.979	0.971	1.192	1.900

Propane (R-290)	2.1	0.038	0.986	0.071	0.087	0.139

R-441A	2.05	0.041	1.000	0.078	0.095	0.152

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. 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 proposes to supplement 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 British
thermal units (BTU) per hour. Equipment manufacturers would be
responsible for designing equipment below a maximum charge size
consistent with the intended cooling capacity. This would allow the
manufacturer, who has greater understanding of the issue than a
consumer, to address the issue in a manner under the manufacturer’s
control. Placing the burden on the manufacturer also provides a better
means for EPA to ensure compliance 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. For instance, packaging, technical
literature and sales display material will often guide a consumer in
choosing the correct capacity for a given room size.

EPA has based its proposed 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, 2013). The proposed charge limits for each refrigerant
by equipment type and mounting location are as follows:

Table 3. Window AC Units*;

Maximum Charge Size by Unit Capacity and Refrigerant Used in Kg

Refrigerant

Charge Size in Kg (by associated capacity in BTU/hr)

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 4. Packaged Terminal AC Units and Heat Pumps and Portable AC
Units:*

Maximum Charge Size by Unit Capacity and Refrigerant Used in Kg

Refrigerant	Charge Size in Kg (by associated capacity in BTU/hr)

	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 5. Wall-Mounted AC Units* with Compressor 1.8 m Above Floor Level:

Maximum Charge Size by Unit Capacity and Refrigerant Used in Kg

Refrigerant	Charge Size in Kg (by associated capacity in BTU/hr)

	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	8.26	9.87	10.81	11.68	12.09
13.96

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 6. Ceiling-Mounted AC Units*:

Maximum Charge Size by Unit Capacity and Refrigerant Used in Kg

Refrigerant	Charge Size in Kg (by associated capacity in BTU/hr)

	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	8.09	8.95	10.09	12.07	13.22	14.28
14.78	17.06

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.

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
would 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 m2 and it is the lowest value observed
at a popular retailer’s website (www.homedepot.com). We request
comment on whether there should be lower, higher, or additional
intermediate capacity values added to these tables.

EPA is requesting comment on the approach of adding a requirement for
manufacturers to design with a maximum charge size consistent with the
design cooling capacity. We also request comment on other potential
methods for supplementing the formulas for calculating charge size in
the UL 484 standard in order to reduce potential risks of a consumer
using a room air conditioner with an inappropriately high charge that
could result in a higher risk of fire.

D. Color-coded hoses and piping

EPA proposes that equipment must have distinguishing color-coded hoses
and piping to indicate use of a flammable refrigerant. This will help
technicians immediately identify the use of a flammable refrigerant,
thereby potentially reducing the risk of using sparking equipment or
otherwise having an ignition source nearby. The air conditioning and
refrigeration industry currently uses distinguishing colors as means for
identifying different refrigerants. 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. EPA is proposing that all such refrigerator tubing be colored
red Pantone Matching System (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.”
This proposal mirrors the existing requirement for the use of
hydrocarbons in residential and commercial refrigerator-freezers
(December 20, 2011, at 76 FR 78832). EPA wants to ensure that there is
adequate notice that a flammable refrigerant is being used within a
particular piece of equipment or appliance. One mechanism to distinguish
hoses and pipes is to add a colored plastic sleeve or cap to the service
tube. The colored plastic sleeve or cap would have to be forcibly
removed in order to access the service tube. This would signal to the
technician that the refrigeration circuit that she/he was about to
access contained a flammable refrigerant, even if all warning labels
were somehow removed. This sleeve would be of the same red color (PMS
#185) and could also be boldly marked with a graphic to indicate the
refrigerant was flammable. This could be a cost-effective alternative to
painting or dying the hose or pipe. EPA is taking comment on this
mechanism of distinguishing the pipe and hose by adding a colored
plastic sleeve or cap to the pipe or hose.

EPA is particularly concerned with ensuring adequate and proper
notification for servicing and disposal of appliances containing
flammable refrigerants. EPA believes the use of color-coded hoses, as
well as the use of warning labels discussed below, would be reasonable
and would be consistent with other general industry practices. This
proposed approach is the same as that adopted in our previous rule on
flammable refrigerants (December 20, 2011, at 76 FR 78832). EPA is
interested in receiving information on how this requirement has been
implemented for those end-uses that are already subject to the earlier
rule, codified in Appendix R to Subpart G of 40 CFR Part 82.

E. Labeling

As a use condition, EPA is proposing to require labeling of household
and retail refrigerators and freezers, vending machines, non-mechanical
heat transfer equipment, very low temperature refrigeration equipment,
and room air conditioners. EPA is proposing the warning labels on the
equipment contain letters at least 1⁄4 inch high. The label must be
permanently affixed to the equipment until its end of life. Warning
label language requirements are found in Section III.A of this proposal,
“What listings is EPA proposing in this action?”  The warning label
language is similar to or exactly the same as that required in UL
standards: for household refrigerators and freezers in UL 250 in section
SA6.1, for vending machines in UL 541 in section SA6.1, for commercial
refrigerators and freezers in UL 471 in section SB6.1, and for room air
conditioning units in UL 484 in section SA6.1.

 that it would be difficult to see warning labels with the minimum
lettering height requirement of 1⁄8 inch in these UL standards.
Therefore, as in the requirements in our previous hydrocarbon
refrigerants rule (December 20, 2011, at 76 FR 78832), EPA is proposing
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 first responders to view the warning labels. We also
understand that UL is considering revising its standards to be
consistent with this requirement, which already applies to equipment
using propane in commercial stand-alone refrigerators and freezers and
equipment using isobutane or R-441A in household refrigerators,
freezers, and combination refrigerator/freezers.

F. Other options not included

EPA considered requiring separate servicing fittings for use with
flammable refrigerants to avoid mixing flammable and non-flammable
refrigerants. We previously considered this option and proposed this as
a use condition in a separate rulemaking in the Federal Register at 75
FR 25799 on May 10, 2010. In the associated final rule at 76 FR 78848 on
December 20, 2011, the Agency did not require separate servicing
fittings but did include this option as a recommendation rather than a
use condition. The types of equipment addressed in this rule are
self-contained pieces of equipment with a hermetically sealed
refrigerant circuit that is only rarely serviced. These are the same as
or similar to the equipment addressed in the December 20, 2011, rule,
and thus with regards to separate servicing fittings we are proposing to
again list this as a recommendation rather than as a use condition. We
have heard some anecdotal mention of concern about mixing of refrigerant
during servicing of appliances, particularly for air conditioning
equipment that is not self-contained. However, this rule is proposing to
address only equipment that is self-contained. Moreover, we do not have
information that would lead us to a different decision than in the
December 20, 2011, final rule for hydrocarbon refrigerants in household
and stand-alone commercial refrigerators and freezers.

We also considered requiring only one use condition for each refrigerant
and end-use--to meet the appropriate standard from Underwriters
Laboratories. We understand that UL may incorporate certain elements of
this proposal, particularly the proposed charge limit and the type font
height for labels, into the UL 250 standard for household refrigerators
and freezers. If those provisions were the only changes incorporated in
a revised version of Supplement A of the UL 250 standard, EPA could
remove the use conditions for charge size and for labeling requirements,
as they would already be incorporated by reference through the use
condition to follow the UL 250 standard. However, at this time, those
changes have not been incorporated into UL 250. Therefore, EPA is
proposing those use conditions as well as compliance with other aspects
of UL 250.

How is EPA proposing to address venting, release, or disposal of the
refrigerant substitutes proposed to be listed under section 608 of the
Clean Air Act?

What are the statutory requirements concerning venting, release, or
disposal of refrigerants and refrigerant substitutes under section 608
of the Clean Air Act?

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), including
air-conditioning and refrigeration equipment. EPA's authority to propose
the actions in this NPRM is based in part on section 608 of the Clean
Air Act. Section 608(c)(1) provides that, effective July 1, 1992, it is:

unlawful for any person, in the course of maintaining, servicing,
repairing, or disposing of an appliance or industrial process
refrigeration, to knowingly vent or otherwise knowingly release or
dispose of any class I or class II substance used as a refrigerant in
such appliance (or industrial process refrigeration) in a manner which
permits such substance to enter the environment.

Section 608(c)(1) further exempts from this self-effectuating
prohibition “[d]e minimis releases associated with good faith attempts
to recapture and recycle or safely dispose” of such a substance. EPA
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).

Effective November 15, 1995, section 608(c)(2) of the Act 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 NPRM.

B. 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 air-conditioning and refrigeration 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., hydrofluorocarbons (HFCs) and perfluorocarbons
(PFCs) in part or whole) during the maintenance, service, repair, or
disposal of appliances. These regulations are codified at 40 CFR Part
82, Subpart F. The regulation at 40 CFR 82.154(a) now states in part
that:

(1)“Effective June 13, 2005, 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:

Ammonia in commercial refrigeration, or in [IPR] or in absorption units;

Hydrocarbons in [IPR] (processing of hydrocarbons);

Chlorine in [IPR] (processing of chlorine and chlorine compounds);

Carbon dioxide in any application;

Nitrogen in any application; or

Water in any application.

(2) The knowing release of a refrigerant or non-exempt substitute
subsequent to its recovery from an appliance shall be considered a
violation of this prohibition. De minimis releases associated with good
faith attempts to recycle or recover refrigerants or non-exempt
substitutes are not subject to this prohibition….”

As explained in EPA's earlier 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). 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 (70
FR 19275; April 13, 2005).

C. What revision to the venting prohibition has EPA recently proposed?

On April 12, 2013, at 78 FR 21871, EPA proposed to revise the existing
venting prohibition for refrigerant substitutes. Those proposed changes
would exempt from that prohibition three hydrocarbon refrigerant
substitutes listed as acceptable subject to use conditions in the
specified end-uses under the SNAP program: isobutane (R–600a) and
R–441A, which were listed as acceptable, subject to use conditions, as
refrigerant substitutes in household refrigerators, freezers, and
combination refrigerators and freezers, and propane (R–290), which was
listed as acceptable, subject to use conditions, as a refrigerant
substitute in retail food refrigerators and freezers (stand-alone units
only). That proposal does not apply to blends of hydrocarbons with other
refrigerants or containing any amount of any CFC, HCFC, HFC, or PFC.

EPA proposed to determine 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 additionally concluded that other authorities,
controls and practices that apply to such refrigerants 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 developed to meet and maintain the NAAQS that would
apply to hydrocarbon refrigerants.

What is EPA’s proposed determination regarding whether venting of
hydrocarbons to be listed as acceptable subject to use conditions in the
end-uses proposed in this NPRM pose 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
substitute refrigerant during the maintenance, servicing, repairing, or
disposing of appliances poses a threat to the environment. See 69 FR
11948 (March 12, 2004). First, EPA determines whether venting, release,
or disposal of the substitute refrigerant poses a threat to the
environment due to inherent characteristics of the refrigerant, such as
global warming potential. Second, EPA determines whether and to what
extent such venting, release, or disposal actually takes place during
the maintenance, servicing, repairing, or disposing of appliances, and
to what extent such venting, release, or disposal is controlled by other
authorities, regulations, or practices. To the extent that such releases
are adequately controlled by other authorities, EPA defers to those
authorities.

1. Potential environmental impacts

EPA has evaluated the potential environmental impacts of releasing into
the environment the hydrocarbon refrigerant substitutes that we are
proposing to list under the SNAP program as acceptable subject to use
conditions in the end-uses proposed--i.e., ethane in very low
temperature refrigeration and non-mechanical heat transfer; isobutane in
retail food refrigeration (stand-alone equipment only) and vending
machines; propane in household refrigerators and freezers, vending
machines and room AC units; and R-441A in retail food refrigeration
(stand-alone equipment only), vending machines and room AC units. 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 and their GWPs, as well as
potential impacts on ecosystems (see Section IV above, “What criteria
did EPA consider in determining whether to list the substitutes as
acceptable and in determining appropriate use conditions and how does
EPA consider those factors?”). As explained in that section, the ODP
of these hydrocarbons is zero, the GWPs are less than 10, and effects on
aquatic life from these hydrocarbons are expected to be small. As to
potential effects on local air quality, based on the analysis and
modeling results described above, EPA concludes that the four saturated
hydrocarbon refrigerant substitutes proposed to be listed as acceptable
subject to use conditions in specific end-uses—ethane, isobutane,
propane, and R-441A—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
proposed rule were to be emitted, there would be a worst-case impact of
less than 0.2% of the NAAQS 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 proposal are not expected to pose a threat to
the environment on the basis of the limited quantities used in the
relevant end-uses and applications and on the basis of the inherent
characteristics of these substances (ICF, 2013a).

 Toxicity and Flammability

As discussed above in sections IV.B., “Flammability and fire safety”
and IV.C., “Toxicity,” EPA’s SNAP program evaluated the potential
for fire risk from flammability and toxicity risks from exposure to the
substitute refrigerants in this proposal. 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 considered in this proposal have lower flammability limits
(LFLs) ranging from 1.8% to 3.0% (18,000 ppm to 30,000 ppm). To address
flammability risks, EPA is issuing recommendations for their safe use
(see section VII, “What recommendations does EPA have for safe use of
the proposed flammable substitute refrigerants?” below) and specified
use conditions. The SNAP program’s analysis suggests that the use
conditions proposed in this rule mitigate flammability risks.

Like most refrigerants, hydrocarbons can displace oxygen at high
concentrations 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 proposed in this rule mitigate potential asphyxiation
and toxicity risks. Furthermore, the Agency believes that the
flammability risks and occupational exposures to hydrocarbons are
adequately regulated by OSHA, building, and fire codes at a local and
national level.

Authorities, Controls, and Practices

EPA believes that existing authorities, controls, and practices would
help mitigate environmental risk from the release of these hydrocarbon
refrigerants. Analyses performed for both this proposed 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 refrigerants proposed to be 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 substitute refrigerants and
mitigate risks from any possible release.

This conclusion is relevant to the second factor mentioned above in the
overall determination of whether venting, release, or disposal of a
substitute refrigerant poses a threat to the environment—that is, a
consideration of 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 refrigerants
would not pose a threat to the environment.

Industry service practices and OSHA standards and guidelines 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. Further, the SNAP rule listing
hydrocarbons as acceptable subject to use conditions for use in
household and commercial stand-alone refrigerators and freezers
(December 20, 2011, at 76 FR 78832), we noted that the amount of
refrigerant from a refrigerant loop is limited (57 g for household
refrigerators and freezers, and 150 g for commercial stand-alone
refrigerators and freezers), indicating that hydrocarbon emissions from
such uses are likely to be relatively small. Similar charge limits are
proposed to apply to very low temperature refrigeration equipment,
non-mechanical heat transfer equipment, and vending machines, with
larger but still limited charges for room air conditioners (1000 g for
hydrocarbon refrigerants).

Hydrocarbons that are also VOC may be regulated as VOC under sections of
the Clean Air Act that address nonattainment, attainment and maintenance
of the National Ambient Air Quality Standards for ground level ozone,
including those sections addressing development of State Implementation
Plans 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 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 could help 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. This conclusion addresses the
second factor in the analysis described above and is thus part of the
determination that the venting, release, or disposal of these
hydrocarbon refrigerant substitutes does not pose a threat to the
environment.

Conclusion

EPA has reviewed the potential environmental impacts of four hydrocarbon
refrigerant substitutes in the end-uses that we are proposing to list
subject to use conditions under SNAP, as well as the authorities,
controls and practices in place for those hydrocarbon refrigerant
substitutes. Specifically, EPA concludes that these four hydrocarbon
refrigerant substitutes in the proposed end-uses and subject to the
proposed 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, and
practices help mitigate environmental risk from the release of those
four hydrocarbons in the proposed end-uses and subject to the proposed
use conditions. In light of these conclusions and those described or
identified above in this section, we are proposing to determine, in
accordance with 608(c)(2), that based on current evidence and risk
analyses, the venting, release or disposal of these four hydrocarbon
refrigerant substitutes in the end-uses proposed does not pose a threat
to the environment. Furthermore, EPA is proposing to exempt from the
venting prohibition at 40 CFR 82.154(a)(1) these additional uses for
which hydrocarbons are being proposed to be found acceptable subject to
use conditions under the SNAP program.

EPA seeks information or data on whether there currently is an industry
standard for recovery units for flammable refrigerants and whether there
are commercially available recovery units that are specifically designed
to be compatible with ethane, isobutane, propane, and R-441A. At this
time, EPA is unaware of any recovery units that are designed
specifically for recovering hydrocarbons and which are readily available
in the U.S. Further, we are not aware of relevant U.S. standards for
such recovery units. However, to the extent that these hydrocarbons are
recovered rather than vented as would be allowed in the specified
end-uses if this proposal became final, EPA recommends the use of
recovery equipment designed for flammable refrigerants, when such
equipment and relevant U.S. standards for it become available, in
accordance with applicable safe handling practices.

What is EPA proposing regarding venting, release, or disposal of
refrigerant substitutes, other than hydrocarbons, included in our
proposed decision?

Today’s proposed rulemaking would regulate the use of HFC-32 in room
AC units. All HFCs are currently subject to the venting prohibition. EPA
is not proposing to extend the exemption to HFC-32 or any refrigerant
blends that contain HFC-32 or any other HFC. Further, the exemption to
the venting prohibition proposed in this NPRM does not extend to blends
of hydrocarbons and other types of compounds, e.g., blends of HFCs and
hydrocarbons. Such refrigerant substitutes would still be subject to the
statutory and regulatory venting prohibition.

What recommendations does EPA have for safe use of the proposed
flammable substitute refrigerants?

EPA recommends that only technicians specifically trained in handling
flammable refrigerant substitutes service or dispose of refrigeration
and air conditioning 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 refrigerant substitutes 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 were vented, released, or
disposed of (rather than recovered), as would be allowed in the
specified end-uses if this proposal became final, the release should be
in a well-ventilated area, such as outside of a building.

We are aware that at least one organization, Refrigeration Service
Engineers Society (RSES), has developed a technician training program in
collaboration with refrigeration equipment manufacturers and users that
addresses 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. EPA intends to update the CAA Section 608 technician
certification test bank provided to approved organizations that
administer the certification exams in accordance with 40 CFR 82.161 to
specifically include questions concerning flammable refrigerant
substitutes.

EPA considered proposing a use condition requiring training in handling
flammable refrigerant substitutes for technicians who service or dispose
of refrigeration and air conditioning equipment containing these
substitutes. However, we do not have sufficient information on the core
elements that should be part of such a training program to ensure that a
training requirement would improve safety. Some examples of potential
core elements that EPA might consider include:

EPA’s relevant use conditions for flammable refrigerants ;

relevant OSHA requirements for flammable gases; relevant industry
standards (e.g., UL, ASHRAE, NFPA);

MSDS information, including first aid and physical and chemical
characteristics of flammable refrigerants; and

requirements and procedures for safe storage and handling of flammable
refrigerants.

EPA requests comment on whether we should establish a use condition
requiring training in handling flammable refrigerant substitutes for
technicians servicing or disposing of equipment containing such
substitutes, and if so, what should be the mandatory elements of such
training.

VIII. Statutory and Executive Order Reviews

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

Under Executive Order (EO) 12866 (58 FR 51735, October 4, 1993), this
action is a “significant regulatory action.” It raises novel legal
or policy issues arising out of legal mandates, the President’s
priorities, or the principles set forth in the Executive Order.
Accordingly, EPA submitted this action to the Office of Management and
Budget (OMB) for review under EO 12866 and 13563 (76 FR 3821, January
21, 2011) and any changes made in response to OMB recommendations have
been documented in the docket for this action.

Paperwork Reduction Act

This action does not impose any new information collection burden. This
proposed rule is an Agency determination. It contains no new
requirements for reporting or recordkeeping. The Office of Management
and Budget (OMB) has previously approved the information collection
requirements contained in the existing regulations in Subpart G of 40
CFR Part 82 under the provisions of the Paperwork Reduction Act, 44
U.S.C. 3501 et seq. and has assigned OMB control number 2060-0226. This
Information Collection Request (ICR) included five types of respondent
reporting and recordkeeping activities pursuant to SNAP regulations:
submission of a SNAP petition, filing a SNAP/TSCA Addendum, notification
for test marketing activity, recordkeeping for substitutes acceptable
subject to use restrictions, and recordkeeping for small volume uses.
The OMB control numbers for EPA’s regulations are listed in 40 CFR
Part 9 and 48 CFR Chapter 15.C.

Regulatory Flexibility Act

The Regulatory Flexibility Act (RFA) generally requires an agency to
prepare a regulatory flexibility analysis of any rule subject to notice
and comment rulemaking requirements under the Administrative Procedure
Act or any other statute unless the agency certifies that the rule will
not have a significant economic impact on a substantial number of small
entities. Small entities include small businesses, small organizations,
and small governmental jurisdictions. For purposes of assessing the
impacts of this rule on small entities, small entity is defined as: (1)
a small business as defined by the Small Business Administration’s
(SBA) regulations at 13 CFR 121.201; (2) a small governmental
jurisdiction that is a government of a city, county, town, school
district or special district with a population of less than 50,000; and
(3) a small organization that is any not-for-profit enterprise which is
independently owned and operated and is not dominant in its field.

After considering the economic impacts of this proposed rule on small
entities, I certify that this action will not have a significant