[Federal Register Volume 76, Number 244 (Tuesday, December 20, 2011)]
[Rules and Regulations]
[Pages 78832-78858]
[FR Doc No: 2011-32175]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 82

[EPA-HQ-OAR-2009-0286; FRL-9507-7]
RIN 2060-AP54

Protection of Stratospheric Ozone: Listing of Substitutes for
Ozone-Depleting Substances--Hydrocarbon Refrigerants

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: Pursuant to the U.S. Environmental Protection Agency (EPA)'s
Significant New Alternatives Policy (SNAP) program, this action lists
isobutane (R-600a) and R-441A as acceptable, subject to use conditions,
as substitutes for chlorofluorocarbon (CFC)-12 and
hydrochlorofluorocarbon (HCFC)-22 in household refrigerators, freezers,
and combination refrigerators and freezers. This action also lists
propane (R-290) as acceptable, subject to use conditions, as a
substitute for CFC-12, HCFC-22, and R-502 in retail food refrigerators
and freezers (stand-alone units only).

DATES: This final rule is effective on February 21, 2012. The
incorporation by reference of certain publications listed in the rule
is approved by the Director of the Federal Register as of February 21,
2012.

ADDRESSES: EPA has established a docket for this action under Docket ID
No. EPA-HQ-OAR-2009-0286. All documents in the docket are listed on the
www.regulations.gov Web site. Although listed in the index, some
information is not publicly available, i.e., confidential business
information (CBI) or other information whose disclosure is restricted
by statute. Certain other material, such as copyrighted material, is
not posted on the Web site and will be made publicly available only in
hard copy form.
    Publicly available docket materials can be found either
electronically in 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<PHONE_NUMBER>, and the
telephone number for the Air and Radiation Docket is<PHONE_NUMBER>.

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

SUPPLEMENTARY INFORMATION:

Table of Contents

I. General Information
    A. Background
    B. Does this action apply to me?
    C. Which acronyms and abbreviations are used in the preamble?
II. How does the SNAP program work?
    A. What are the statutory requirements and authority for the
SNAP program?
    B. What are EPA's regulations implementing section 612?
    C. How do the regulations for the SNAP program work?
    D. Where can I get additional information about the SNAP
program?
III. What did EPA propose, and what are we finalizing?
    A. Proposed Rule
    B. Final Rule
IV. What is the basis for EPA's final action?
    A. Environmental Impacts
    B. Flammability
    C. Asphyxiation
    D. Toxicity
V. What is EPA's response to comments on the May 2010 notice of
proposed rulemaking?
    A. EPA's Acceptability Determination
    B. New Equipment Only; Not Intended for Use as a Retrofit
Alternative
    C. Compliance With UL Standards
    D. Charge Size Limitation (Household Refrigeration)
    E. Charge Size Limitation (Retail Food Refrigeration)
    F. Labeling
    G. Color-Coded Hoses and Piping
    H. Unique Fittings
    I. Small Containers
    J. Use of Hydrocarbon Refrigerants in Other End-Uses
    K. Training
    L. Other Options Considered
    M. Other Comments on Proposed Rule
VI. What other changes is EPA making in the final rule?
    A. Propane as Substitute for R-502
    B. Wording of Use Conditions for Labeling
    C. ``Further Information'' Column in Listing Decisions
VII. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From
Environmental Health and Safety Risks
    H. Executive Order 13211: Actions That Significantly Affect
Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions To Address
Environmental Justice in Minority Populations and Low-Income
Populations
    K. Congressional Review Act
VIII. References

I. General Information

A. Background

    This rule pertains to three hydrocarbon refrigerants: Isobutane,
propane, and R-441A. Hydrocarbon refrigerants have been in use for over
15 years in countries such as Germany, the United Kingdom, Australia,
and Japan in the end-uses addressed by this final rule. In Europe and
Asia, equipment manufacturers have designed and tested household and
commercial refrigerators and freezers to account for flammability and
safety concerns associated with hydrocarbon refrigerants.
    The 2010 Report of the United Nations Environment Programme
(UNEP)'s Refrigeration, Air Conditioning and Heat Pumps Technical
Options Committee (RTOC) estimates that approximately 100 million
household refrigerators and freezers are manufactured annually
worldwide. One-third of these now use either isobutane or an isobutane/
propane blend, and this proportion is expected to increase to 75
percent by 2020. In the retail sector, the RTOC observes that
hydrocarbon refrigerants continue to gain market share in Europe and
Japan.\1\
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    \1\ RTOC, 2010, pp. 50, 51, 64.
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    Because hydrocarbon refrigerants have zero ozone depletion
potential (ODP) and very low global warming potential (GWP) compared to
other refrigerants, many companies are interested in using them in the
United States (U.S.) as well. In this action, EPA addresses SNAP
submissions for use of three hydrocarbon refrigerants in two end-uses:
(1) Household refrigerators, freezers, and combination refrigerators
and freezers; and (2) retail food refrigerators and freezers (stand-
alone units only).
    The submitter of R-441A--A.S. Trust and Holdings--has provided
documentation to EPA, available in the docket for this rulemaking, that
it has withdrawn its submission for the blend originally submitted as
``HCR-188C.'' Because the submission is no longer pending before EPA,
we are not

finalizing a SNAP listing for that blend. Any person wishing to
introduce that blend into interstate commerce would be required to
submit a new SNAP application under EPA regulations.\2\
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    \2\ The submitter has informed EPA that that it is now marketing
R-441A (the blend originally submitted as ``HCR-188C1'') under the
trade name ``HCR-188C.''
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1. What are isobutane, propane, and R-441A?
    Isobutane and propane are hydrocarbons, and R-441A is a blend of
hydrocarbons. Hydrocarbons are flammable organic compounds made up of
hydrogen and carbon.
    Isobutane, also called 2-methylpropane, has four carbon atoms, the
chemical formula C4H10, and a branched structure.
It is often written as CH(CH3)2-CH3 to
distinguish it from butane, a straight-chain hydrocarbon with the same
chemical formula. Isobutane's Chemical Abstracts Service (CAS) Registry
Number is 75-28-5. As a refrigerant, isobutane is designated as R-600a
by the American Society of Heating, Refrigerating and Air-Conditioning
Engineers (ASHRAE) Standard 34-2010 ``Designation and Safety
Classification of Refrigerants'' (ASHRAE, 2010). It is also referred to
as HC-600a and iso-C4H10.
    Propane has three carbon atoms, the chemical formula
C3H8, and the CAS Number 74-98-6. As a
refrigerant, propane has ASHRAE designation R-290. It is also referred
to as HC-290 and CH3CH2CH3.
    R-441A is a blend of four hydrocarbons: Ethane (3.1 percent by
mass), propane (54.8 percent by mass), isobutane (6.0 percent by mass),
and butane (36.1 percent by mass). This blend was originally submitted
to EPA under the trade name ``HCR-188C1,'' and EPA used that
nomenclature in the proposed rule (75 FR 25799). In February 2011, this
blend received the designation R-441A under ASHRAE Standard 34-2010.\3\
Throughout this final rule, we refer to that blend as R-441A.
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    \3\ See Addendum g to Standard 34-2010.
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    ASHRAE Standard 34-2010 categorizes isobutane, propane, and R-441A
in the A3 safety group. ASHRAE's safety group classification consists
of two alphanumeric characters (e.g., A2 or B1). The capital letter
indicates the toxicity, and the numeral denotes the flammability.
    Figure 1 illustrates these safety group classifications.
    [GRAPHIC] [TIFF OMITTED] TR20DE11.000

    ASHRAE classifies Class A refrigerants as refrigerants for which
toxicity has not been identified at concentrations less than 400 ppm by
volume, based on data used to determine a workplace exposure limit for
long-term exposure, such as a threshold limit value-time-weighted
average (TLV-TWA) or consistent indices. Class B refrigerants show
evidence of toxicity below 400 ppm on an 8-hour time-weighted average
(TWA).
    Refrigerants also receive one of three possible flammability
classifications: 1 (no flame propagation), 2 (lower flammability), or 3
(higher flammability). Class 3 refrigerants exhibit flame propagation
at 60 [deg]C and 101.3 kPa, and have either a lower flammability limit
(LFL) of less than or equal to 0.10 kg/m\3\ or a heat of combustion
greater than or equal to 19,000 kJ/kg.
2. Which end-uses are covered in our final decision?
a. Household Refrigerators, Freezers, and Combination Refrigerators and
Freezers
    This end-use, which we refer to as ``household refrigeration'' in
this preamble, consists of appliances that are intended primarily for
residential use, although they may be used outside the home. Household
freezers offer storage space only at freezing temperatures. Products
with both a refrigerator and freezer in a single unit are most common.
This final rule includes a use condition that limits the refrigerant
charge in this end-use to 57 grams (2.0 ounces) or less for each sealed
refrigeration system (i.e., compressor, condenser, evaporator, and
refrigerant piping). EPA is also requiring other use conditions as
described in Section III (``What did EPA propose, and what are we
finalizing?'') below.
b. Retail Food Refrigerators and Freezers (Stand-Alone Units Only)
    This end-use, which we refer to as ``retail food refrigeration'' in
this preamble, includes the refrigeration systems, including cold
storage cases, designed to chill food or keep it at a cold temperature
for commercial sale. This final rule addresses the use of hydrocarbons
in stand-alone units only.

A stand-alone appliance is one using a hermetically-sealed compressor
and for which all refrigerant-containing components, including but not
limited to at least one 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 addition or
removal of refrigerant when placed into initial operation. Stand-alone
equipment is used to store chilled beverages or frozen products.
Examples include reach-in beverage coolers and stand-alone ice cream
cabinets. Our acceptability determination does not apply to large
refrigeration systems such as walk-in coolers or the direct expansion
refrigeration systems typically found in retail food stores. It also
does not apply to vending machines.
    This final rule includes a use condition that limits the
refrigerant charge in this end-use to 150 grams (5.3 ounces) or less.
EPA is also requiring other use conditions as described in Section III
(``What Did EPA Propose, and What are we finalizing?'') below.

B. Does this action apply to me?

    This final rule lists the use of three alternative refrigerants in
two end-uses: Household refrigerators, freezers, and combination
refrigerators and freezers; and retail food refrigerators and freezers
(stand-alone units only). Potentially regulated entities that may use
isobutane (R-600a) or R-441A in household refrigeration or propane (R-
290) in retail food refrigeration include:

  Table 1--Potentially Regulated Entities, by North American Industrial
             Classification System (NAICS) Code or Subsector
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                             NAICS code  or    Description of regulated
         Category               subsector              entities
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Industry..................            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  Electrical and Electronic
                                               Appliance, Television,
                                               and Radio Set Merchant
                                               Wholesalers.
Industry..................            423740  Refrigeration Equipment
                                               and Supplies Merchant
                                               Wholesalers.
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    This table is not intended to be exhaustive, but rather functions
as a guide regarding entities that are likely to use the substitute
whose use is regulated by this action. If you have any questions about
whether this action applies to a particular entity, consult the person
listed in the preceding section, FOR FURTHER INFORMATION CONTACT.

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

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

AEGL--Acute Exposure Guideline Level
ASHRAE--American Society of Heating, Refrigerating and Air-
Conditioning Engineers
ANSI--American National Standards Institute
CAA--Clean Air Act
CAS--Chemical Abstracts Service
CBI--confidential business information
CFC--chlorofluorocarbon
CFR--Code of Federal Regulations
CO2--carbon dioxide
EPA--United States Environmental Protection Agency
FR--Federal Register
FTA--Fault-Tree Analysis
GHG--greenhouse gas
GWP--global warming potential
HC--hydrocarbon
HCFC--hydrochlorofluorocarbon
HFC--hydrofluorocarbon
ICF--ICF International, Inc.
ICR--information collection request
IEC--International Electrotechnical Commission
kg--kilogram
LFL--lower flammability limit
NAICS--North American Industrial Classification System
NARA--National Archives and Records Administration
NOAEL--no observable 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
OMB--United States Office of Management and Budget
OSHA--United States Occupational Safety and Health Administration
PMS--Pantone[supreg] Matching System
ppm--parts per million
RFA--Regulatory Flexibility Act
RfC--reference concentration
RTOC--Refrigeration, Air Conditioning and Heat Pumps Technical
Options Committee
SNAP--Significant New Alternatives Policy
TEAP--Technology and Economic Assessment Panel
TLV--Threshold Limit Value
TSCA--Toxic Substances Control Act
TUV--Technischer Uberwachungs-Verein (German Technical Inspection
Agency)
TWA--time-weighted average
UL--Underwriters Laboratories Inc.
UMRA--Unfunded Mandates Reform Act
UNEP--United Nations Environment Programme
VOC--volatile organic compound
WGL--workplace guidance level
WMO--World Meteorological Organization

II. How does the 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:
1. Rulemaking
    Section 612(c) requires EPA to promulgate rules making it unlawful
to replace any class I substance (i.e., chlorofluorocarbon, halon,
carbon tetrachloride, methyl chloroform, methyl bromide, and
hydrobromofluorocarbon) or class II substance (i.e.,
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 is found at http://www.epa.gov/ozone/snap/lists/index.html, and the lists of substitutes
that are ``unacceptable,'' ``acceptable subject to use conditions,''
and ``acceptable subject to narrowed use limits'' are in subpart G of
40 CFR part 82.
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 are EPA's regulations 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 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 requires EPA to ensure that substitutes
found acceptable do not present a significantly greater risk to human
health and the environment than other substitutes that are currently or
potentially available.

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

    Under the SNAP regulations, anyone who plans to market or produce a
substitute to replace a class I substance or class II substance in one
of the eight major industrial use sectors 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. This requirement applies to the
persons planning to introduce the substitute into interstate
commerce,\4\ which typically are chemical manufacturers but may include
importers, formulators, equipment manufacturers, and end-users.\5\ The
regulations identify certain narrow exemptions from the notification
requirement, such as research and development and test marketing (40
CFR 82.176(b)(4) and (5), respectively).
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    \4\ As defined at 40 CFR 82.104, ``interstate commerce'' means
the distribution or transportation of any product between one state,
territory, possession or the District of Columbia, and another
state, territory, possession or the District of Columbia, or the
sale, use or manufacture of any product in more than one state,
territory, possession or District of Columbia. The entry points for
which a product is introduced into interstate commerce are the
release of a product from the facility in which the product was
manufactured, the entry into a warehouse from which the domestic
manufacturer releases the product for sale or distribution, and at
the site of United States Customs clearance.
    \5\ As defined at 40 CFR 82.172, ``end-use'' means processes or
classes of specific applications within major industrial sectors
where a substitute is used to replace an ODS.
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    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 in
the paragraphs below. Substitutes that are deemed acceptable with no
use restrictions (no use conditions or narrowed use limits) can be used
for all applications within the relevant end-uses in the sector.
    After reviewing a substitute, the Agency may determine that a
substitute is acceptable only if certain conditions in the way that the
substitute is used are met to minimize risks to human health and the
environment. EPA describes such substitutes as ``acceptable subject to
use conditions.'' Entities that use these substitutes without meeting
the associated use conditions are in violation of EPA's SNAP
regulations.
    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.'' The Agency requires the user of a
narrowed-use substitute to demonstrate that no other acceptable
substitutes are available for the specific application by conducting
comprehensive studies. 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.
    The Agency publishes its SNAP program decisions in the Federal
Register (FR). EPA publishes 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 with an opportunity to comment,
before publishing final decisions.
    In contrast, EPA publishes decisions concerning substitutes that
are deemed acceptable with no restrictions in ``notices of
acceptability,'' rather than as proposed and final rules. As described
in the March 18, 1994, rule initially implementing the SNAP program,
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 U.S. Occupational Safety and Health Administration (OSHA)). The
``Further Information'' classification 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 can I get 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 Layer Protection
Web site at: www.epa.gov/ozone/snap/index.html. For more information on
the Agency's process for administering the SNAP program or criteria for
evaluation of substitutes, refer to the March 18, 1994, SNAP final
rulemaking (59 FR 13044), codified at 40 CFR part 82, subpart G. A
complete chronology of SNAP decisions and the appropriate citations is
found at: http://www.epa.gov/ozone/snap/chron.html.

III. What did EPA propose, and what are we finalizing?

A. Proposed Rule

    On May 10, 2010, EPA published a notice of proposed rulemaking (75
FR 25799) to list isobutane (R-600a) and the hydrocarbon blends HCR-
188C and HCR-188C1 as ``acceptable, subject to use conditions,'' as
substitutes for chlorofluorocarbon (CFC)-12 and hydrochlorofluorocarbon
(HCFC)-22 \6\ in household refrigerators, freezers, and combination
refrigerators and freezers.\7\ (This preamble refers to HCR-188C1 as R-
441A.)
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    \6\ CFC-12 is also referred to as R-12,
CCl2F2 and dichlorodifluoromethane. HCFC-22 is
also referred to as R-22, CHClF2, chlorodifluoromethane,
and difluorochloromethane.
    \7\ HCR-188C and HCR-188C1 submissions included window air
conditioners as an end-use. EPA is acting on this end-use in a
separate rulemaking. As discussed previously, ``HCR-188C'' is the
name of a blend that has been withdrawn from review for the
household food refrigeration end-use.
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    EPA also proposed to list propane (R-290) as ``acceptable, subject
to use conditions,'' as a substitute for CFC-12, HCFC-22, and R-502 \8\
in retail food refrigerators and freezers (stand-alone units only).
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    \8\ R-502 is a blend of CFC-115 (51.2% by weight) and HCFC-22
(48.8%). CFC-115 is also referred to as R-115,
C2ClF5, chloropentafluoroethane, and
pentafluorochloroethane.
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    For each substitute, EPA proposed the following use conditions:
    (1) 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).
    (2) These refrigerants may be used only in refrigerators or
freezers that meet all requirements listed in the 10th edition of
Underwriters Laboratories (UL) Standard UL 250 (household refrigeration
end-use) or the 9th edition (sic) of Standard UL 471 (retail food
refrigeration end-use).
    (3) The quantity of the substitute refrigerant (i.e., ``charge
size'') in a refrigerator or freezer shall not exceed 57 grams (2.0
ounces) in the household refrigeration end-use or 150 grams (5.3
ounces) in the retail food refrigeration end-use.
    (4) Similar to clauses SA6.1.1 to SA6.1.2 of UL 250 and SB6.1.2 to
SB6.1.5 of UL 471, the following markings, or the equivalent, shall be
provided and shall be permanent:
    (a) ``DANGER--Risk of Fire or Explosion. Flammable Refrigerant
Used. Do Not Use Mechanical Devices To Defrost Refrigerator. Do Not
Puncture Refrigerant Tubing.''
    (b) ``DANGER--Risk of Fire or Explosion. Flammable Refrigerant
Used. To Be Repaired Only By Trained Service Personnel. Do Not Use
Mechanical Devices. Do Not Puncture Refrigerant Tubing.''
    (c) ``CAUTION--Risk of Fire or Explosion. Flammable Refrigerant
Used. Consult Repair Manual/Owner's Guide Before Attempting To Service
This Product. All Safety Precautions Must be Followed.''
    (d) ``CAUTION--Risk of Fire or Explosion. Dispose of Properly In
Accordance With Federal Or Local Regulations. Flammable Refrigerant
Used.''
    (e) ``CAUTION--Risk of Fire or Explosion Due To Puncture Of
Refrigerant Tubing; Follow Handling Instructions Carefully. Flammable
Refrigerant Used.''
    The marking described in clause (a) above shall be permanently
attached on or near any evaporators that can be contacted by the
consumer. The markings described in clauses (b) and (c) above shall be
located near the machine compartment. The marking described in clause
(d) above shall be permanently attached on the exterior of the
refrigerator. The marking described in clause (e) above shall be
permanently attached near any and all exposed refrigerant tubing. All
of these markings shall be in letters no less than 6.4 mm (1/4 inch)
high.
    (5) The refrigerator or freezer must have red, Pantone[supreg]
Matching System (PMS) 185 marked pipes, hoses, or other
devices through which the refrigerant passes, typically known as the
service port, to indicate the use of a flammable refrigerant. This
color must be applied at all service ports and parts of the unit where
service puncturing or otherwise creating an opening from the
refrigerant circuit to the atmosphere might be expected, and must
extend a minimum of 1 inch in both directions from such locations.
    (6) The refrigerator or freezer must have service aperture fittings
that differ from fittings used in equipment or containers using non-
flammable refrigerant. ``Differ'' means that either the diameter must
differ by at least 1/16 inch or the thread direction must be reversed.
The unique fittings must be permanently affixed to the unit and may not
be accessed with an adaptor until the end-of-life of the unit.
    (7) These refrigerants may not be sold for use as a refrigerant in
containers designed to contain less than 5 pounds (2.3 kg) \9\ of
refrigerant.
---------------------------------------------------------------------------

    \9\ The proposed rule inadvertently represented 5 pounds as 2.8
kilograms instead of 2.3 kg, which is accurate.
---------------------------------------------------------------------------

    The proposed rule also included several recommendations classified
as ``Further Information.'' These addressed personal protective
equipment, proximity to a Class B dry powder-type fire extinguisher,
proper ventilation, use of spark-proof tools, recovery equipment,
training, refrigerant storage, and evacuation.
    Finally, in the proposed rule, EPA sought information and comment
on several other issues:
     The availability of industry-wide training on flammable
refrigerants for refrigerant technicians;
     Whether EPA should limit the use of hydrocarbon
refrigerants only for use in the original equipment manufacturers'
(OEMs') specific appliances, as described in the application;
     Whether the use conditions should require ``spark-proof''
circuits in the design of equipment using hydrocarbon refrigerants;
     The availability in the U.S. of recovery units that are
designed specifically for hydrocarbons;
     Whether EPA should, in a future rulemaking, consider an
exemption for hydrocarbon refrigerants from the venting prohibition
under section 608 of the Clean Air Act;
     Whether EPA should require only one condition for each
refrigerant: to meet the UL 250 or 471 standards; and

     Whether EPA should find hydrocarbon refrigerants
unacceptable until an industry-wide standard exists for servicing
refrigerators and freezers using hydrocarbon refrigerants.

B. Final Rule

    After considering the comments received on the proposed rule, EPA
is finalizing a listing for hydrocarbon refrigerants in the household
refrigeration and retail food refrigeration end-uses.
    EPA is taking action on the specific refrigerant/end-use
combinations described in the proposed rule. We are: (1) Finding
isobutane acceptable, subject to use conditions, in the household
refrigeration end-use; (2) finding propane acceptable, subject to use
conditions, in the retail food refrigeration end-use; and (3) finding
R-441A (submitted as ``HCR-188C1,'' as discussed in Section I.A.1
above) acceptable, subject to use conditions, in the household
refrigeration end-use. As discussed above, the submitter has withdrawn
its application for the blend submitted as ``HCR-188C,'' and because
that submission is no longer pending before the Agency, EPA is not
finalizing a SNAP listing for that blend. The submitter has informed
EPA that it is now marketing R-441A (the blend originally submitted as
``HCR-188C1'') under the trade name ``HCR-188C.''
    For each of the listing decisions finalized in this action, we are
establishing the following use conditions after considering comments on
the proposed rule:
    (1) EPA is finalizing the proposed requirement that these
refrigerants 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 that is designed for other refrigerants). See Section V.B of
this preamble (``New Equipment Only; Not Intended for Use as a Retrofit
Alternative'').
    (2) EPA is finalizing the proposed requirement that these
refrigerants be used only in refrigerators or freezers that meet all
requirements listed in Supplement SA to UL 250 (household refrigeration
end-use) or Supplement SB to UL 471 (retail food refrigeration end-
use). We clarify that the intent of this use condition is to require
compliance with the provisions specifically for use with flammable
refrigerants found in those supplements, rather than requiring
compliance with other material in UL 250 and UL 471 that is not
specific to use with flammable refrigerants. See Section V.C
(``Compliance with UL Standards'').
    (3) EPA is finalizing the proposed requirement for 57-gram and 150-
gram charge size limitations for the household refrigeration and retail
food refrigeration end-uses, respectively. We are also clarifying that
the charge size limitations apply to each refrigerant circuit in a
refrigerator or freezer, not necessarily the entire appliance. See
Sections V.D (``Charge Size Limitation (Household Refrigeration)'') and
V.E (``Charge Size Limitation (Retail Food Refrigeration)'').
    (4) EPA is finalizing the marking (labeling) requirements as
proposed, as discussed in Section V.F (``Labeling''), with two minor
exceptions discussed in Section VI (``What Other Changes Is EPA Making
in the Final Rule?''). First, we are correcting the wording of the
label located at the machine compartment; second, we are clarifying the
language of the requirement to more clearly link each label with its
wording and location.
    (5) EPA is finalizing the proposed requirement that the
refrigerator or freezer have red PMS 185-marked pipes, hoses,
or other devices through which the refrigerant passes. We are narrowing
the applicability of this requirement by clarifying that the color must
be present at all locations through which the refrigerant is serviced,
and where service puncturing or otherwise creating an opening from the
refrigerant circuit to the atmosphere might be expected (e.g., process
tubes), instead of all locations where the refrigerant passes. In
addition, we are clarifying that the red coloring must be in place at
all times and must be replaced if removed. See Section V.G (``Color-
Coded Hoses and Piping'').
    (6) Based on the comments received, EPA is not finalizing the
proposed requirement for unique fittings at service apertures. Instead
we are providing this as a recommendation in the ``Further
Information'' column of Appendix R. See Section V.H (``Unique
Fittings'').
    (7) Based on the comments received, EPA is not finalizing the
proposed requirement prohibiting the sale of hydrocarbon refrigerants
in containers designed to contain less than 5 pounds (2.3 kg) of
refrigerant. See Section V.I (``Small Containers'').
    EPA is also making two other changes to the wording of the use
conditions and ``Further Information'' provisions in Appendix R. First,
we are clarifying that R-502 is one of the refrigerants for which
propane is listed as a substitute in the retail food refrigeration end-
use. Second, we are including in the ``Further Information'' column a
cross-reference to relevant OSHA regulations.

IV. What is the basis for EPA's final action?

    To determine whether these three substitutes present risks that are
lower than or comparable to risks from other substitutes that are
currently or potentially available in the end-uses under consideration,
we examined the criteria in 40 CFR 82.180(a)(7), focusing in particular
on the following areas of concern: Impacts on stratospheric ozone and
climate; volatile organic compound (VOC) emissions; flammability;
asphyxiation risks for consumers and end-users; and toxicity risks to
workers, consumers, and the general population.
    In support of the proposed rule, in 2009, EPA performed a risk
screen analysis for each of the substitutes for the end-use proposed
for listing: Isobutane in household refrigeration (ICF, 2009a), propane
in retail food refrigeration (ICF, 2009b), HCR-188C in household
refrigeration (ICF, 2009c), and HCR-188C1 (R-441A) in household
refrigeration (ICF, 2009d). In developing this final rule, EPA reviewed
these risk screens and made minor changes for greater consistency and
clarity, but made no substantive changes to the assumptions or to the
quantitative risk calculations. (EPA did not revise the risk screen for
HCR-188C, since the manufacturer withdrew the application for that
refrigerant, and EPA is not finalizing an acceptability determination
for the refrigerant.) The 2009 risk screens and the 2011 revisions
(ICF, 2011a; ICF, 2011b; ICF, 2011c) are included in the docket for
this rulemaking.
    Based on the information provided in the risk screens, EPA has
concluded that the overall environmental risk posed by each of the
three substitutes is lower than or comparable to the environmental
risks posed by other substitutes in the reviewed end-uses. With respect
to public health risks, EPA has concluded that without mitigation, the
risks posed by these refrigerants would be higher than other 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 flammability risks. Therefore,
EPA is finalizing use conditions to ensure that the overall risks to
human health and the environment posed by these substitutes are lower
than or comparable to the overall risk posed by other substitutes in
the same end-use.

A. Environmental Impacts

    EPA has concluded that, overall, the environmental risk posed by
each of the three reviewed substitutes is lower than or comparable to
the environmental risk posed by other substitutes in the reviewed end-
uses. All three substitutes have zero ozone depletion potential (ODP)
and very low global warming potential (GWP) compared to other
refrigerants. Although the substitutes are VOCs, the emissions from the
specific uses being found acceptable subject to use conditions would
not significantly affect local air quality. Thus the environmental
risks associated with ODP, GWP, and VOC effects for each reviewed
substitute are lower than or comparable to other acceptable
substitutes. These risks are discussed below.
    A chemical's ODP is the ratio of its impact on stratospheric ozone
compared to the impact of an identical mass of CFC-11.\10\ The ODP of
CFC-11 is defined as 1.0. Other CFCs and HCFCs have ODPs ranging from
0.01 to 1.0 (WMO, 2011). The ODP of HCFC-22 is 0.055, and the ODP of R-
502 is 0.334. The three substitutes discussed in this rule have an ODP
of zero, as do other common substitutes in the same end-uses, such as
HFC-134a, R-404A, and R-410A.
---------------------------------------------------------------------------

    \10\ CFC-11, CAS registry No. 75-69-4, is also referred to as R-
11, CCl3F and trichlorofluoromethane.
---------------------------------------------------------------------------

    The GWP of a greenhouse gas (GHG) quantifies its potential
integrated climate forcing relative to carbon dioxide (CO2)
over a specified time horizon. The 100-year integrated GWPs of
isobutane, propane, and R-441A are estimated to be 8 (GE, 2008), 3 (Ben
and Jerry's, 2008), and less than 5 (A.S. Trust & Holdings, 2009),\11\
respectively, relative to a value of 1.0 for CO2. These are
significantly lower than the 100-year integrated GWPs of the substances
that they would be replacing: CFC-12 (GWP = 10,890); HCFC-22 (GWP =
1,810); and R-502 (GWP = 4,660) (WMO, 2011) and are significantly lower
than those of other acceptable refrigerants in these end-uses (e.g.,
GWPs of HFC-134a, R-404A, and R-410A are approximately 1,430, 3,920,
and 2,090, respectively).
---------------------------------------------------------------------------

    \11\ The submission for HCR-188C1, now known as R-441A, reported
that the GWP of the substitute is ``negligible or essentially
zero.'' Because the main components of R-441A are the same as the
main components of the HCR-188C formulation originally submitted,
the GWP of R-441A is expected to be similar to that reported for the
original formulation by A.S. Trust & Holdings, Inc. (2007).
---------------------------------------------------------------------------

    The overall climate impacts from the use of these refrigerants are
also dependent upon the energy use by the appliances in which they are
used, because the indirect climate impacts associated with electricity
consumption typically exceed those from the refrigerants themselves
over the full life cycle of refrigerant-containing products (ORNL,
1997). A hydrocarbon appliance that is more energy-efficient than the
appliance it replaces would result in GHG emission reductions beyond
those attributable to the substitute refrigerant alone. Conversely, the
GHG benefits of a substitute refrigerant in a replacement hydrocarbon
appliance would be offset if that appliance had lower energy efficiency
than the appliance it replaces. EPA was unable to find any detailed
life-cycle analysis addressing GHG emissions associated with
substituting traditional ODS refrigerants with hydrocarbons.
Information in the submissions indicates that energy efficiency of
these refrigerants is likely to be comparable to or higher than that of
ODS refrigerants and of HFC refrigerants sometimes used (e.g., HFC-
134a) (Ben & Jerry's, 2008; A.S. Trust & Holdings, 2007, 2009; GE,
2008). In the 2010 Assessment Report of the Technology and Economic
Assessment Panel, UNEP's Technology and Economic Assessment Panel
(TEAP) discusses the energy efficiency of hydrocarbons compared to that
of HFC-134a:

    When GWP of HFC-134a is considered prohibitive in relation to
HFC emissions (country regulation or company policy), hydrocarbon
refrigerants (isobutane and propane, i.e. HC-600a and HC-290) or
CO2 (R-744) are the current alternative solutions,
presenting in most of the cases the same technical reliability and
energy performance as HFC-134a. [p. 60]

    Hydrocarbons are regulated as VOCs under sections of the CAA that
address development of State Implementation Plans to attain and
maintain National Ambient Air Quality Standards for ground-level ozone,
which is a respiratory irritant (see 40 CFR 51.100(s)). EPA's 1994 risk
screen document (EPA, 1994) describes the potential emissions of VOCs
from all substitutes for all end-uses in the refrigeration and air-
conditioning sector as likely to be insignificant relative to VOCs from
all other sources (i.e., other industries, mobile sources, and biogenic
sources). Analysis performed for this rulemaking indicates that in the
extremely unlikely event that all appliances manufactured by each
submitter in these two end-uses were to leak their entire charge over
the course of a year, the resulting increase in annual VOC emissions
from each substitute as a percent of all annual VOC emissions in the
U.S. would be negligible.\12\
---------------------------------------------------------------------------

    \12\ As a percent of annual VOC emissions in the U.S., this
represents approximately 5 x 10-6 percent (for isobutane
in the household food refrigeration end-use) (ICF, 2009a and ICF,
2011a), 5 x 10-6 percent (for propane in the retail food
refrigeration end-use) (ICF, 2009b and ICF, 2011b), and 3 x
10-7 percent (for R-441A in the household food
refrigeration end-use) (ICF, 2009d and ICF, 2011c).
---------------------------------------------------------------------------

    Therefore, the use of these hydrocarbons in the household
refrigeration and retail food refrigeration end-uses is sufficiently
small that a switch from an ODS or from an HFC refrigerant would not
have a noticeable impact on local air quality. International experts
came to a similar conclusion in Safeguarding the Ozone Layer and the
Global Climate System: Special Report of the Intergovernmental Panel on
Climate Change (IPCC/TEAP, 2005).
    Similarly, EPA expects that additional releases of hydrocarbons
into the environment from use as refrigerant will have an insignificant
impact on ecosystem risks. Because hydrocarbons are volatile and break
down quickly in the atmosphere into naturally-occurring compounds such
as carbon dioxide, EPA would not expect there to be any significant
amount of deposition that might adversely affect aquatic or terrestrial
ecosystems.

B. Flammability

    Because they are flammable, isobutane, propane, and R-441A could
pose a significant safety hazard for workers and consumers if handled
incorrectly. Isobutane, propane, and R-441A have lower flammability
limits (LFLs) \13\ of 18,000 ppm, 21,000 ppm, and 16,000 ppm,
respectively. The ODS for which these refrigerants are substitutes--
CFC-12, HCFC-22, and R-502--and other substitutes available in this
end-use are not flammable. When the concentration of a flammable
refrigerant reaches or exceeds its LFL in the presence of an ignition
source (e.g., a static electricity spark resulting from closing a door,
use of a torch during servicing, or a short circuit in wiring that
controls the motor of a compressor), an explosion or fire could occur.
---------------------------------------------------------------------------

    \13\ LFL is the minimum concentration in air at which flame
propagation occurs.
---------------------------------------------------------------------------

    Flammability risks are of particular concern because household
refrigeration appliances and retail food refrigeration appliances in
the United States traditionally have used refrigerants that are not
flammable. Without mitigation, the risks posed by flammable
refrigerants would be higher than those posed by non-flammable
refrigerants because individuals may not be aware that their actions
could cause a fire, and

existing appliances have not been designed specifically to minimize
flammability risks.
    Therefore, in order for these substitutes to be used safely, it is
important to minimize the presence of potential ignition sources and to
reduce the likelihood that the levels of these refrigerants will reach
their LFLs. Production facilities, and other facilities where large
quantities of the refrigerant are stored, should have proper safety
precautions in place to minimize the risk of explosion. EPA recommends
that these facilities be equipped with proper ventilation systems to
minimize the risks of explosion and be designed to reduce risks from
possible ignition sources.
    To determine whether the three hydrocarbon refrigerants would
present flammability concerns for service and manufacture personnel or
for consumers, EPA reviewed the submitters' detailed assessments of the
probability of events that might create a fire, as well as engineering
approaches to avoid sparking from the refrigeration equipment. EPA also
conducted risk screens, available in the docket for this rulemaking,
evaluating reasonable worst-case scenarios to model the effects of the
sudden release of the refrigerants. The worst-case scenario analysis
for each of the three hydrocarbons revealed that even if the unit's
full charge were emitted within one minute, the concentration would not
reach the LFL for that hydrocarbon.
    However, since hydrocarbon refrigerants are flammable, and
manufacture personnel, service personnel, and consumers in the U.S. may
not be widely familiar with refrigeration appliances containing
flammable refrigerants, use conditions are necessary to create
awareness of the presence of a flammable refrigerant and ensure safe
handling. For this reason, this final rule includes use conditions in
order to ensure that these substitutes present aggregate risks that are
lower than or comparable to those of other substitutes that are
currently or potentially available. This final rule also lists
recommendations such as proper ventilation and storage practices, and
use of appropriate tools and recovery equipment, to mitigate safety
risks for manufacture and servicing personnel.

C. Asphyxiation

    In evaluating potential human health impacts of isobutane, propane,
and R-441A, EPA considered the risk of asphyxiation to workers (store
employees and technicians) and consumers. The Agency evaluated a worst-
case scenario that did not consider likely mitigating exposure
conditions such as open doors or windows, fans, conditioned airflow, or
infiltration between a door and its door frame. EPA calculated the
maximum charge of each refrigerant that would result in a reduction of
oxygen levels to 12 percent in air, which is the no observable adverse
effect level (NOAEL) for hypoxia (ICF, 1997). Specifically, under the
worst-case conditions evaluated, the charge sizes necessary to reduce
the oxygen level in air to the 12-percent NOAEL in the household
refrigeration end-use would be 625 grams and 535 grams (for isobutane
and R-441A, respectively), which is much larger than the 57-gram charge
size limitation required in the use conditions in this rule (ICF, 2011a
and 2011c). Likewise, the charge size necessary to achieve the NOAEL in
the retail food refrigeration end-use would be 904 grams for propane,
which is six times greater than the 150-gram charge size limitations in
this rule (ICF, 2011b). This risk is lower than or comparable to that
of other available substitutes in these end-uses.

D. Toxicity

    EPA evaluated the toxicity impacts of the three refrigerants to
workers and consumers for the household refrigeration and retail food
refrigeration end-uses. The Agency estimated the maximum time-weighted
average (TWA) \14\ exposures for the hydrocarbons under different
exposure scenarios and compared them to relevant industry and
government exposure limits for each of the three hydrocarbons
(including potential impurities in the substitutes). The risk screens,
provided in the docket, describe the toxicity impact assessments in
more detail (ICF, 2009a; ICF, 2009b; ICF, 2009d; ICF, 2011a, ICF,
2011b, ICF, 2011c).
---------------------------------------------------------------------------

    \14\ Time-weighted average (TWA) = The average concentration of
a specific substance in air over a specified time period--e.g.,
during the course of an 8-hour work day.
---------------------------------------------------------------------------

    To assess occupational exposure for the household refrigeration and
retail food refrigeration end-uses, EPA estimated the number of
refrigerant releases during appliance manufacture and disposal and the
refrigerant amounts released per event. For each refrigerant, EPA used
those estimates to calculate the maximum 8-hour TWA exposure, which we
then compared to the corresponding workplace guidance level (WGL). EPA
found that occupational exposures to these hydrocarbons should not pose
a toxicity threat in either end-use because the TWAs were well below
the industry and government exposure limits.
    To assess consumer and end-user exposure for the household
refrigeration end-use, EPA modeled 15- and 30-minute TWAs for
catastrophic refrigerant release in a consumer kitchen under a
reasonable worst-case scenario. Even under the very conservative
modeling assumptions used, EPA found that exposures to any of the three
hydrocarbons would not pose a toxicity threat to end-users in the
household refrigeration end-use because the TWAs were significantly
lower than the NOAEL and/or acute exposure guideline level (AEGL).
    To assess consumer and end-user exposure for the retail food
refrigeration end-use, EPA estimated 15- and 30-minute TWAs as acute/
short-term consumer exposures resulting from catastrophic leakage of
refrigerant from retail food refrigerators and compared the TWAs to
standard toxicity limits. EPA concluded that none of the three
hydrocarbons posed a toxicity threat to consumers in the retail end-use
because the TWAs were significantly lower than the NOAEL and/or AEGL.
    Finally, EPA assessed the exposure risk to the general population
for the three hydrocarbons in their respective end-uses. To do so, EPA
estimated factory and on-site releases of each hydrocarbon and compared
them to each hydrocarbon's reference concentration (RfC).\15\ In all
cases, the modeled exposure concentrations were significantly lower
than the RfC, leading EPA to conclude that isobutane, propane, and R-
441A are unlikely to pose a toxicity risk to the general population.
These toxicity risks are lower than or comparable to those posed by the
other acceptable substitutes in these end-uses.
---------------------------------------------------------------------------

    \15\ The RfC is a concentration designed to protect the general
population against adverse systemic (i.e., non-cancer) health
effects.
---------------------------------------------------------------------------

V. What is EPA's response to comments on the May 2010 notice of
proposed rulemaking?

    In this section, EPA responds to comments on the May 10, 2010,
notice of proposed rulemaking (NPRM).

A. EPA's Acceptability Determination

    Comment: Ninety-nine commenters expressed unconditional support for
EPA's proposal to find isobutane and R-441A acceptable (subject to use
conditions) in the household refrigeration end-use and to find propane
acceptable (subject to use conditions) in the retail food refrigeration
end-use.

    Response: We appreciate the support for our proposed action, and we
are taking final action consistent with that proposal.
    Comment: One commenter observed that although hydrocarbon
refrigerants provide some environmental benefit by reducing GHG
emissions, they pose flammability risks that more than offset that
benefit. The commenter stated that the global warming impacts of HFC
refrigerants are currently small due to their low emissions (except in
the case of catastrophic leaks), and practices are in place to recover
refrigerant and destroy foam at an appliance's end-of-life. The
commenter also observed that hydrocarbon refrigerants could enter the
refrigerant recovery/recycle chain during servicing or at the end-of-
life, necessitating costly upgrades to recycle/recovery equipment in
order to mitigate potential flammability risks.
    Response: EPA reviews substitutes according to regulatory criteria
provided at 40 CFR 82.180(a)(7) and described above. EPA has evaluated
the hydrocarbon refrigerants against these criteria and has concluded
that they present overall environmental and human health risks that are
lower than or comparable to other acceptable substitutes in the
household refrigeration and retail food refrigeration end-uses. EPA
agrees that flammability risks could be a concern for these
refrigerants in these end-uses. But, for the two end-uses at issue in
this rule, where charges are limited and there is a long history of
safe use globally, EPA believes risks can be mitigated to ensure the
substitutes can be used as safely as other available substitutes. We
are establishing use conditions to ensure that these substitutes pose
an overall risk to human health and the environment that is lower than
or comparable to the overall risk posed by other substitutes in the
same end-uses.
    With respect to the comment regarding risks during servicing and at
end-of-life, EPA agrees that flammability could pose a concern for the
servicing and disposal of appliances containing hydrocarbon
refrigerants. However, the use conditions in this final rule address
this potential risk. For example, the labeling requirements and the
requirement for coloring of tubing will serve as notification to
servicing or disposal personnel that an appliance contains a flammable
refrigerant.
    Section V.L (below) also discusses recovery equipment. Based on
comments received, EPA believes that recovery equipment designed
specifically for flammable refrigerants is not yet widely manufactured
or available in the U.S., although certain commenters observed that
they have created their own equipment to meet this need in their own
business practices.
    Comment: Another commenter provided detailed comments on EPA's risk
screen for the use of isobutane in the household refrigeration end-use
and limited comments on EPA's risk screen for the use of propane in the
retail food refrigeration end-use. The commenter stated that EPA has
underestimated the safety risks associated with the use of hydrocarbon
refrigerants. The comments covered the following:
    1. A fault-tree analysis calculating the probability of failures
that would lead to ignition of the refrigerant;
    2. The results of an external leak test in a mockup kitchen to
illustrate the consequences of an external leak;
    3. The results of an internal leak test and a deflagration/
explosion test to illustrate the consequences of an internal leak;
    4. An observation about a manufacturer's major recall of certain
models of isobutane refrigerators in 2009 as a result of safety
incidents in Asia and Europe; and
    5. A statement of similar concerns about the use of propane in
small commercial refrigeration systems.
    This section of the preamble summarizes these comments and EPA's
response.
    Comment 1: Fault tree analysis.
    Comment: The commenter included a fault-tree analysis (FTA) that
assessed the probability of household refrigerator ignition events due
to the random coincidence of ignition sources and internal refrigerant
leaks. An FTA considers how likely different events are and how
resistant a system is to various faults. The commenter's FTA analyzed
several potential scenarios in which ignition events could take place
in household refrigerators. The commenter's FTA calculated that
isobutane household refrigerators in the U.S. would experience: (a) 2.9
ignition events per year at full market penetration as a result of
independent, random events, and (b) an additional 2.5 ignition events
for every 10 million refrigerators that enter the market due to a
specific coupled failure in which the malfunction of the defrost heater
is both the cause of the leak and the ignition source. The commenter
concluded that EPA potentially underestimated the risk of ignition-
related failures in residential refrigerators for internal leak events.
Details of the two calculations are presented below.
    (a) Failure scenarios based on independent, random events. The
commenter's FTA identified two events that, occurring simultaneously,
could potentially lead to an ignition event: (1) An internal isobutane
refrigerant leak and (2) the occurrence of an energy source with
sufficient energy to cause ignition. The commenter's FTA identified and
calculated probabilities for the different ways in which each of these
events could happen.
    To calculate the probability of an internal leak event, the
commenter made assumptions regarding: The number of refrigerator
repairs due to joint leakage and evaporator corrosion that might be
related to a leak; the number of refrigerator repairs annually (based
on the estimated amount of HFC-134a currently sold for use in
servicing); and a multiplier accounting for the number of leaking
refrigerators that would be thrown away instead of repaired. Based on
these assumptions, the commenter estimated that isobutane refrigerators
would experience approximately 260,000 internal leak failures per year
in the U.S. at full market penetration (which the commenter estimated
at approximately 150 million refrigerators).
    To calculate the probability of an energy source with sufficient
energy to cause ignition, the commenter's FTA estimated the probability
of sparks from internal switches and controls, the defrost heater, and
static electricity, asserting that any of these sparks would have
sufficient energy to ignite a leak. The commenter's FTA calculated the
likelihood of an ignition source as 11.2 in 1,000,000.
    The commenter's FTA integrated the above assumptions and estimates
to calculate an expected 2.9 ignition events per year at U.S. full
market penetration.
    (b) ``Coupled leak failure'' scenario. The commenter asserted that
in addition to the random, independent events assessed above, the
defrost heater presents a risk of a coupled failure because an electric
short to the evaporator coil can be the cause of both the refrigerant
leak and the ignition event. The commenter took three factors into
account to determine the total number of ignition events from this
coupled failure: (1) The probability that the defrost heater will
short-circuit, (2) the probability that an arc from the defrost heater
will cause a refrigerant leak, and (3) the probability that the
refrigerant will be present in sufficient quantities to ignite (i.e.,
whether the concentration will be at the LFL or higher). The commenter
estimated that for every 10 million household refrigerators using
isobutane that are produced, there would be an estimated 2.5 failure
events in which an electrical short to the evaporator coil causes both

a refrigerant leak and an ignition over the lifetime of those units.
The commenter clarified that this value is in addition to the ignition
events calculated in the previous FTA, which would result from the
coincidence of independent, random events.
    Response: While EPA believes that the commenter has overestimated
failure probabilities, we agree with the commenter that the risks
associated with the use of isobutane in household refrigerators are
greater than zero. EPA believes, however, that these risks are
sufficiently small and should not preclude a determination that
isobutane is acceptable for use subject to use conditions that are for
the purpose of mitigating the potential risks.
    EPA's interpretation of the risk of ignition-related failures in
residential refrigerators for internal leak events is based on
information presented in ``Risk Assessment of Flammable Refrigerants
for Use in Home Appliances'' (A.D. Little, 1991). The A.D. Little
report, available in the docket for this rulemaking, included an FTA in
which leak rate calculations were based on historical leak rate data
provided by three refrigerator manufacturers. As explained in more
detail below, EPA believes that many elements of the commenter's FTA
are undocumented, are at odds with the industry data used in the A.D.
Little report, and present internal analytical inconsistencies.
    (a) Failure scenarios based on independent, random events.
Regarding the failure scenarios based on independent, random events, we
note that the commenter's discussion of methodology, the equation used
for the calculation, and the calculations in the commenter's FTA were
inconsistent with each other, making it difficult to evaluate what had
been done. Based on the commenter's discussion of methodology, EPA
believes that the commenter's FTA applied assumptions that are either
undocumented or unsupported by industry data. One such assumption is
particularly problematic: The commenter's analysis appears to have
considered all leaks as potential risks for ignition. However, in order
for a leak to pose a potential risk for ignition, the refrigerant must
be present in amounts that meet or exceed the LFL. The ability of a
refrigerant to accumulate and reach its LFL is a function of both the
rate at which the leak occurs and the presence of enclosed spaces that
can trap the refrigerant and allow it to build up. Neither of these
conditions was accounted for in the commenter's probability
calculations.
    As previously mentioned, the A.D. Little report calculated leak
rates from historical leak rate data provided by three refrigerator
manufacturers. A.D. Little distinguished ``catastrophic'' leaks (the
loss of a significant portion of refrigerant charge over a few minutes)
from ``slow'' leaks, observing that only catastrophic or ``fast'' leaks
would allow refrigerant to accumulate to a level of concern. The report
goes on to calculate the ``average'' risk that a leak is a fast leak as
0.1 percent and the ``worst-case'' risk that a leak is a fast leak as 1
percent. EPA believes that the commenter's failure to distinguish
``slow'' from ``fast'' leaks causes the commenter's analysis to
overestimate the risk of an ignitable leak by at least two orders of
magnitude.
    Furthermore, today's rule finalizes use conditions that guard
against the potential that refrigerant from a ``fast'' leak will be
able to accumulate in amounts that reach the LFL, or that an ignition
source would cause an ignition event in the case of a significant leak.
The use conditions require any household refrigerator using isobutane
to be designed specifically for use with flammable refrigerant in a
manner that complies with the UL 250 Standard. UL 250, Supplement SA,
``Requirements for Refrigerators and Freezers Employing a Flammable
Refrigerant in the Refrigerating System,'' is intended to protect
against an ignition incident in the event of a refrigerant leak. Units
that are in compliance with UL 250 (particularly Supplement SA) have
passed appropriate ignition or leakage tests as stipulated in the
standard. Passing the leakage test (at SA <IP_ADDRESS> and SA <IP_ADDRESS>)
ensures that refrigerant concentrations in the event of a leak do not
reach or exceed 75 percent of the LFL inside any internal or external
electrical component compartments.
    (b) ``Coupled leak failure'' scenario. EPA's concerns about the
independent variables underlying the coupled leak failure scenario are
the same as those articulated above for randomized events. The
commenter did not provide clear documentation or a rationale for how
estimates were derived.
    EPA believes that the commenter overestimated the probability that
a defrost heater would cause a leak and cause ignition because the
calculation neglected to account for an important factor: the
probability of a defrost cycle coinciding with the time period during
which concentrations in the compartment reach the LFL. Even if a
refrigerant is present in sufficient quantity (i.e., at LFL), it will
not ignite if there is no ignition source. For example, if the door to
a compartment that contains refrigerant at LFL is opened before a new
defrost cycle begins and the refrigerant dissipates to concentrations
below the LFL, then no ignition event will take place, when the next
defrost heater cycle begins and an arc occurs. The commenter claimed
that the defrost cycle is only active 2 percent of the time (for three
10-minute periods per day). Had the commenter incorporated this factor
into the calculations, the number of coupled leak failures would be
approximately 50 times lower, dropping from 2.5 per 10 million units to
about 0.05 per 10 million units. Since this is the probability of a
coupled leak failure over the lifetime of a unit, and the average
lifetime of a unit is estimated to be a minimum of 10 years, this would
correspond to at most 0.08 ignition events per year at full market
penetration (approximately 150 million refrigerators, according to the
commenter) due to a coupled leak failure. We consider this a reasonable
risk level. Moreover, use conditions in this final rule should further
decrease the likelihood of such an event occurring, and that these
risks are sufficiently small and should not preclude a determination
that isobutane is acceptable for use, subject to use conditions that
are for the purpose of mitigating potential risks.
    Comment 2: External leak test.
    The commenter presented results from an experiment that mimicked a
leak from an isobutane refrigerator using a bottom-freezer refrigerator
located inside a controlled ambient chamber and performed test
measurements of isobutane levels in a mockup kitchen. The commenter
stated that the experiment followed the leak procedure in the UL 250
standard, including the following setup:
     A kitchen intended to closely resemble a typical U.S.
kitchen;
     A bottom-freezer refrigerator located inside a control
ambient chamber;
     A 57-gram charge of isobutane; and
     Eight calibrated Henze-Hauck concentration sensors near
potential ignition sources.

    After running the test, the commenter stated that five sensors
showed isobutane concentrations exceeding the LFL for several minutes.
The commenter used these results as the basis of an assertion that EPA
underestimated the risks from external leaks.
    Response: To assess the commenter's experiment fully, EPA would
require values for the commenter's test parameters and supporting
documentation. Based on the information provided, however, we have the
following responses.

    We note that the commenter's experiment was meant to simulate a
worst-case scenario leak. Based on industry data in the A.D. Little
report, the annual probability of a catastrophic leak outside a given
refrigerator is typically 3.6 x 10-7, with a worst-case
probability of 9.0 x 10-6.
    The commenter did not provide the make and model of the
refrigerator used, and did not describe whether it was designed
specifically to use isobutane as a refrigerant. Since EPA is requiring
any isobutane refrigerator to be designed specifically for use with
flammable refrigerant and to comply with Supplement SA of UL 250 for
use with flammable refrigerants, results from a test for a refrigerator
not designed to meet the requirements of Supplement SA would not
reflect the risks associated with an isobutane refrigerator that is
compliant with the use conditions in this final rule. Even if the
refrigerator were specifically designed for use with an isobutane
refrigerant and fully compliant with all portions of the UL 250
Standard, EPA believes that the leaked refrigerant at the locations of
the five sensors showing isobutane concentrations at or exceeding the
LFL is not likely to ignite for the reasons discussed below.
    The commenter's experiment leaked an unrealistically large amount
of refrigerant, causing slightly higher measurements for isobutane
concentrations than could be expected in the actual event of a leak. As
described in Section V.D of this preamble (Charge Size Limitation--
Household Refrigeration), the proposed and final rules limit the charge
size for each sealed refrigerant system to 57 grams, with a use
condition for compliance with the UL 250 Standard Supplement SA, which
calls for a charge size that will not leak more than 50 grams of
hydrocarbon refrigerant with properties similar to isobutane. Thus, a
leak of 57 grams, such as the one described in the commenter's
experiment, is not consistent with a possible leak from an isobutane
refrigerator that is compliant with the use conditions in this final
rule.
    The first of the five sensors that showed isobutane concentrations
above the LFL registered a maximum level of 1.9% for approximately 0.6
minutes (36 seconds). This was just barely above the LFL of 1.8% and
had a duration of less than a minute. The sensor would have measured a
concentration at or above the LFL for less than 0.6 minutes, if at all,
if the test had leaked a realistic amount of refrigerant based on the
use conditions in the proposed and final rules.
    The concentrations measured at the four other sensors likely still
would have been higher than the LFL, even if a realistic amount of
refrigerant had been leaked. However, EPA does not believe that there
are likely ignition sources present at those locations, which are near
the compressor relay, on the floor behind the refrigerator, on the
floor just in front of the refrigerator, and on the floor 2.5 meters in
front of the refrigerator. If the refrigerator were designed in
accordance with the UL 250 Standard as required by this rule, then
there would be no ignition sources in either of the first two
locations, or the refrigerator would be designed in such a way that the
LFL would not be reached near an ignition source in those
locations.\16\ As for the last two sensors, EPA disagrees with the
commenter's assertion that these locations are a likely source of
sparks. While not impossible, we believe it is highly unlikely that a
major external leak would occur and at the same time, someone would
light a match or cigarette in their kitchen and then drop it on the
floor. We note that the LFL was not reached at the sensor located near
a more likely spark source--30 inches above the floor at an electrical
outlet.
---------------------------------------------------------------------------

    \16\ Under SA5.1 of the Standard, a leakage test is required to
ensure that refrigerant concentrations measured near any internal or
external electrical component cannot exceed 75% of the LFL at any
point in time and, furthermore, cannot exceed 50% of the LFL for
more than 5 minutes at a time. (SA<IP_ADDRESS>, SA<IP_ADDRESS>). For any
locations in which the LFL exceeds these amounts, the product would
need to pass an ignition test (SA5.2) and a temperature test (SA
5.3) to ensure that electrical and heating components will not
ignite the specific flammable refrigerant under consideration in
order to comply with UL 250.
---------------------------------------------------------------------------

    In response to the commenter's general observation that EPA's risk
screen may underestimate risks, EPA revisited the assumptions made in
the end-use modeling for both isobutane and R-441A in the household
refrigeration end-use to identify opportunities for a more conservative
analysis. The results of this analysis are provided in a memo,
``Additional end-use modeling for household refrigerators and
freezers'' (ICF, 2011d), which is provided in the docket for this
rulemaking. This exercise identified two parameters for which
assumptions could be more conservative:
     Leak amounts were increased to 57 grams (representing the
entire allowable charge size) rather than 50 grams (for isobutane) and
40 grams (for R-441A), which were the intended charge sizes submitted
by the applicants. While a leak amount of 57 grams is greater than that
allowed by the UL 250 Standard, this additional analysis conservatively
accounts for the possibility of incorrect manufacturer testing of the
product. (We note that a refrigerator that leaks more than 50 grams of
isobutane or R-441A refrigerant would not be in compliance with UL 250,
and therefore would be in violation of the use conditions of this
rule.)
     Stratification was more conservatively modeled through the
assumption that 95 percent of the leaked refrigerant mixes evenly into
the bottom 0.2 meters (9 inches) of the room, rather than the bottom
0.4 meters as assumed in the risk screen.
    Using these more conservative assumptions, EPA performed additional
flammability and threshold analysis. EPA found that even with a higher
leak amount and a greater degree of stratification, the LFL was not
reached in the model for either refrigerant. Furthermore, it would take
a 75-gram leak in an 18 m\3\ kitchen or a 57-gram leak in a 13.8 m\3\
kitchen to meet or exceed the LFL in the lower portion of the room for
isobutane. Likewise, it would take a 59-gram leak in an 18 m\3\ kitchen
or a 57-gram leak in a 17.3 m\3\ kitchen to meet or exceed the LFL in
the lower compartment of the room for R-441A. It should be noted that a
survey of kitchen sizes found the smallest kitchen volume to be 31
m\3\, with 99 percent of kitchens having a volume of at least 53 m\3\
(Murray, 1997 as cited in ICF, 2009a; ICF, 2009d; ICF, 2011a; and ICF,
2011c). Thus the results of this more conservative and protective
modeling do not indicate a significant cause for concern that would
cause us to change our determination that isobutane and R-441A are
acceptable subject to use conditions for use in the household
refrigeration end-use.
    Depending on the mixing conditions, it is still possible that in
certain locations at floor level, or in restricted areas such as the
space between a refrigerator and a wall, the concentrations of
isobutane or R-441A could reach their LFLs for a few minutes, posing a
threat in the presence of a spark. However, in the worst case, the
annual probability of a ``fast'' external leak occurring and an
ignition source being present simultaneously is approximately 5.0 x
10-7, or 0.5 in a million) (A.D. Little, 1991).
    Comment 3: Internal leak test and explosion/deflagration
experiment.
    The commenter provided a cursory description of an internal leak
test that measured isobutane concentrations inside the freezer
compartment. The commenter concluded that refrigerant concentrations
inside the freezer compartment reached 3.2 percent, which exceeds the
LFL of 1.8 percent.

    The commenter also described the results of a test to reproduce the
deflagration/explosion when an internal leak is ignited. The commenter
stated that it performed a leakage test according to UL 250 on a U.S.
market refrigerator with original components, including the defrost
heater, in outdoor ambient conditions. The test leaked 57 grams of
refrigerant and used an unidentified sparking source to simulate a
faulty defrost heater connection in the freezer compartment. The result
was a violent explosion that sent heavy objects, such as the freezer
door, flying up to 48 feet high. The commenter argued that this
demonstrates that 57 grams of isobutane would produce enough energy to
result in structural damage.
    Response: As was the case for the external leak test, the commenter
provided neither the make and model of the refrigerator used, nor a
statement regarding whether the refrigerator was designed specifically
to use isobutane. Since EPA is requiring all isobutane refrigerators to
be designed specifically for use with flammable refrigerant and to
comply with Supplement SA of UL 250 for use of flammable refrigerants,
results from a test for a non-compliant refrigerator would not reflect
the risks associated with an isobutane refrigerator that is in
compliance with the use conditions in this rule. As previously noted,
Supplement SA is intended to protect against an ignition incident in
the event of a refrigerant leak. Units that are in compliance with
Supplement SA of UL 250 have passed appropriate ignition or leakage
tests as stipulated in the standard. Passing the leakage test (at SA
<IP_ADDRESS> and SA <IP_ADDRESS>) ensures that refrigerant concentrations in the
event of a leak do not reach 75 percent of the LFL inside food
compartments.
    EPA also notes that the commenter's experiment was meant to
simulate a worst-case scenario leak. Based on industry data in the A.D.
Little report, the annual probability of a fire or explosion inside a
given refrigerator is 2.7 - 10-13 on average, with a worst-
case probability of 7.0 - 10-12. This latter value
corresponds to roughly 0.001 ignition events per year (or 1 ignition
event every 1,000 years) at full market penetration (approximately 150
million refrigerators, according to the commenter) under a worst-case
scenario. We consider this a reasonable risk level. Again, we note that
the use conditions in this final rule should further decrease the
likelihood of such an event occurring, and that these risks are small
enough not to preclude a determination that isobutane is acceptable for
use subject to the use conditions required by this final rule.
    Comment 4: Recall of isobutane refrigerators.
    The commenter described a major recall of certain models of
isobutane refrigerators. In 2009 a major consumer refrigerator
manufacturer announced a recall of isobutane refrigerators as a result
of safety incidents that occurred in Asia and Europe. These incidents
occurred despite the fact that these units were specifically designed
to operate with isobutane, and were designed to eliminate potential
ignition sources. The electrical insulation in the defrost mechanism in
these units carbonized, leading to partial short-circuiting and
sparking. The sparking corroded the adjacent tubing, which resulted in
a leak of hydrocarbon refrigerant. Isobutane concentrations accumulated
enough to exceed the LFL in the closed refrigerator unit. During the
next defrost cycle, the faulty electrical circuit resulted in ignition
of the refrigerant and an explosion.
    Response: The recall discussed in this comment occurred in October
2009 and involved approximately 400,000 refrigerators in South Korea
and Europe that were manufactured between March 2005 and June 2006.
According to the manufacturer, the recall was triggered by an October
29, 2009, explosion of an isobutane refrigerator in Gyeonggi, South
Korea. Press accounts also discuss a small number of related incidents
in the United Kingdom and Germany between 2006 and 2009. Addressing the
problem under the recall involved home visits to install a safety
device to prevent the defrost heater from overheating.
    EPA notes that this final rule requires all isobutane refrigerators
to comply with the provisions of Supplement SA to UL 250. These
provisions include leakage, ignition, and temperature tests, as well as
an accelerated aging test of heater terminal seals and an insulation
resistance test of all defrost heaters. These tests are not included in
the standards established by the International Electrotechnical
Commission (IEC) that would have been applicable to the appliances
under recall.
    EPA also notes that more than 400 million hydrocarbon refrigerator
units are in use worldwide; in China alone, 75 percent of new domestic
refrigerators/freezers use isobutane. Refrigerator ignition incidents
resulting from leaked isobutane appear to be rare considering the
widespread use of hydrocarbon refrigerators worldwide.
    Comment 5: Use of propane in small commercial refrigeration
systems.
    The commenter includes a brief observation that the use of propane
in small commercial refrigeration systems poses risks similar to use of
isobutane in residential refrigerators. The commenter also argues that
larger hydrocarbon charges pose a higher risk of ignition events, and
that small commercial refrigeration systems are known to have much
higher leakage frequencies and failure rates than residential systems.
    Response: As discussed above, EPA performed a risk screen on the
use of propane in small commercial refrigeration systems (ICF, 2009b,
revised as ICF, 2011b), which is available in the docket for this
rulemaking. The risk screen indicates that propane's LFL is not reached
in the retail food refrigeration end-use where the charge size does not
exceed that established by the use conditions. As described in the risk
screen, under a worst-case (catastrophic) release scenario the maximum
instantaneous concentration of propane in the lowest stratum of the
room would be approximately 66 percent of the LFL and the concentration
in the upper part of the room would be lower. Further, the SNAP
application for this end-use pointed out that no catastrophic
(``fast'') leaks had been reported from among the 270,000 hydrocarbon
refrigerators in operation belonging to the submitter.
    The commenter did not provide information to refute EPA's risk
screen for retail food refrigeration. EPA's flammability assessment
indicates that the risk of explosion is extremely small in this end-
use.

B. New Equipment Only; Not Intended for Use as a Retrofit Alternative

    EPA received ten comments on its proposed requirement that
hydrocarbon refrigerants ``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).'' Nine of the commenters supported
restricting the use of hydrocarbon refrigerants to new equipment only.
    Comment: One commenter requested that retrofitting old household
refrigerators and freezers and retail food refrigerators (stand-alone
equipment only) be allowed. The commenter suggested that safety
concerns could be alleviated by allowing retrofitting only by personnel
who are trained to handle flammable refrigerants.
    Response: Under the SNAP program, an application for SNAP approval
specifies whether the proposed refrigerant use is for new equipment,

retrofitted equipment, or both. None of the submissions applied for use
in retrofitted equipment. The Agency did not conduct a risk analysis
for use of the substitutes in retrofitted equipment, nor did any of the
comments provide such an analysis. Therefore, EPA is not addressing
such use at this time.
    EPA would consider whether to find hydrocarbon refrigerants
acceptable for use in retrofitted equipment in the future if sufficient
evidence, including a risk assessment, is provided and shows that such
use will present risks to human health and the environment that are
lower than or comparable to risks from other available substitutes.

C. Compliance With UL Standards

    EPA received ten sets of comments on its proposed requirement that
the hydrocarbon refrigerants be used only in refrigerators or freezers
that meet all requirements listed in the Underwriters Laboratories (UL)
Standard for Household Refrigerators and Freezers, UL 250 (for the
household refrigeration end-use) \17\ and the UL Standard for
Commercial Refrigerators and Freezers, UL 471 (for the retail food
refrigeration end-use).\18\ Most commenters supported adherence to
applicable UL standards, although some offered the following additional
comments.
---------------------------------------------------------------------------

    \17\ EPA is referencing Supplement SA (``Requirements for
Refrigerators and Freezers Employing a Flammable Refrigerant in the
Refrigerating System'') from UL Standard 250, ``Household
Refrigerators and Freezers,'' 10th edition.
    \18\ EPA is referencing the UL Standard 471, 9th edition
Supplement SB; ``Requirements for Refrigerators and Freezers.
---------------------------------------------------------------------------

    Comment: One commenter recommended that a final rule be contingent
upon the existence and acceptance of a comprehensive industry-wide
safety standard. The commenter also suggested that EPA could add other
standards to the list of references addressing the safety of
hydrocarbon refrigerants. The commenter referred to ANSI Standard
Z21.24,\19\ ASHRAE Standard 15,\20\ UL Standard 21,\21\ EN 378,\22\
ISO-5149,\23\ the IOR Safety Code of Practice for Refrigerating Systems
Utilising A2 & A3 Refrigerants,\24\ and AS/NZS 1677.\25\
---------------------------------------------------------------------------

    \19\ American National Standards Institute (ANSI) Z21.24:
Connectors for Gas Appliances.
    \20\ ASHRAE Standard 15-2010: Safety Standard for Refrigeration
Systems.
    \21\ UL 21: Standard for LP-Gas Hose.
    \22\ EN 378: Refrigerating systems and heat pumps--Safety and
environmental requirements. Prepared by European Committee for
Standardization/Technical Committee CEN/TC 182 (Refrigerating
systems, safety and environmental requirements).
    \23\ International Organization for Standardization. ISO 5149:
Mechanical refrigerating systems used for cooling and heating--
Safety requirements.
    \24\ IOR (Institute of Refrigeration): Safety code of practice
for refrigerating systems utilising A2 and A3 refrigerants.
    \25\ The Joint Australian Standard/New Zealand Standard (AS/NZS)
1677: Addresses safety, design, construction, installation, testing,
inspection, operation and maintenance of refrigeration systems.
---------------------------------------------------------------------------

    Response: It is unclear what was intended by either comment.
Regarding the first comment, EPA notes that the UL standards are in
fact industry-wide safety standards. UL has tested equipment for
flammability risk in both household and retail food refrigeration. UL
also has developed acceptable safety standards including requirements
for construction, for marking, and for leakage, ignition, and
temperature tests, as well as an accelerated aging test of heater
terminal seals and an insulation resistance test of all defrost
heaters.
    With respect to the second comment, it is unclear whether the
commenter is suggesting that the other standards be imposed as use
conditions, whether they should be included in the ``Further
Information'' column of the regulations, or whether they should simply
be described in this preamble. The commenter provided no reasoning as
to why the listed standards should be included either as use conditions
or in the ``Further Information'' column of the regulation, and we are
not aware that these standards provide any additional protections that
are not provided by this rule. EPA believes that the use conditions
established in this final rule will ensure that these substitutes will
present risks that are lower than or comparable to the risks from other
available alternatives.

D. Charge Size Limitation (Household Refrigeration)

    EPA received ten comments on its proposed charge size limitation of
57 grams (2.0 ounces) for the household refrigeration end-use.
    Comment: Five commenters recommended a limit of 150 grams (5.3
ounces) to correspond to standards established by the International
Electrotechnical Commission (IEC 60335-2-24), including two non-
governmental organizations, a manufacturer of refrigerator compressors,
and two manufacturers of household refrigerators and freezers. One of
these commenters, an environmental organization, observed that over 400
million refrigerators using propane and isobutane refrigerants are in
use worldwide and that they generally are certified to the 150-gram
international safety standard. The commenter stated that EPA has not
provided a justification for a 57-gram charge size limit.
    One commenter, a manufacturer of household refrigerators and
freezers, stated that the 57-gram charge size limit in some cases would
reduce the efficiency of the appliance and raise the indirect GHG
emissions associated with the product's energy use. Two commenters, a
manufacturer of household refrigerators and freezers and an
environmental organization, observed that the UL 250 standard could
change in the future and recommended that EPA should modify its charge
size limitation to harmonize with UL 250 as it changes over time.
    Three of the commenters supported the 57-gram limitation, including
a manufacturer of household refrigerators and freezers that submitted
to the SNAP program for hydrocarbon refrigerant in this end use; a
manufacturer of commercial refrigerators and freezers that submitted to
the SNAP program for hydrocarbon refrigerant in both household and
commercial refrigerators and freezers; and a manufacturer of commercial
refrigerators and freezers.
    Response: EPA agrees with the comments supporting the proposed
requirement that the charge size not exceed 57 grams for household
refrigeration. UL 250 allows a maximum leak amount of 50 grams (1.8
ounces), and the submitter used procedures outlined in the UL 250
leakage test to conclude that up to 7 grams of additional refrigerant
charge could be solubilized in the oil (and assumed not to leak or
immediately vaporize with the refrigerant in the event of a leak). This
information was reflected in EPA's risk screen for isobutane, which
modeled a maximum refrigerant release of 50 grams (ICF, 2009a and ICF,
2011a).
    It is true that hundreds of millions of refrigerators and freezers
using propane and isobutane refrigerants in other countries are
certified to the IEC 60335-2-24 standard, which allows for a charge of
hydrocarbon refrigerant up to 150 g. However, available evidence
suggests that most of these appliances actually have charges that are
closer to 57 g than to 150 g. For comparison, a typical U.S. household
refrigerator using HFC-134a has a charge of roughly 140 g,\26\ and a
charge of isobutane providing comparable cooling would be 40 to 50% of
the charge of HFC-134a,\27\ or 56 to 70 g. It is EPA's understanding
that most European household refrigerators are smaller than the typical
U.S. household refrigerator and that they use less charge; thus, we
would expect that

European household refrigerators have charge sizes less than 70 g. The
commenter's own Web site states, ``[T]oday's hydrocarbon refrigerators,
with hermetically sealed compressor systems, use between 30 to 70 grams
of refrigerant, depending on the size of the refrigerator.'' \28\ Thus,
the safety record of hydrocarbon refrigerators and freezers in Europe
appears to reflect experience primarily with charge sizes much smaller
than 150 g.
---------------------------------------------------------------------------

    \26\ A. D. Little, 2002.
    \27\ ACRIB, 2001.
    \28\ Greenpeace, 1997.
---------------------------------------------------------------------------

    While EPA could assess various charge sizes on a theoretical basis,
we do not have the resources to perform product testing and we rely
primarily on industry, national safety standard organizations, and non-
governmental organizations to conduct tests on appliances. UL has
tested household refrigerators, freezers, and combination refrigerators
and freezers for safety, especially with respect to flammability
concerns, and the U.S. insurance industry and commercial sector rely on
the results of those tests. Testing by manufacturers and UL addresses
flammability in the manufacturing process as well as how the product
functions with different charge sizes. UL developed the 50-gram
allowable leak limit as the result of testing during development of the
UL 250 standard for household refrigerators and freezers. The 50-gram
allowable leak limit for household refrigerators in UL 250 differs from
the 150-gram allowable leak limit for commercial refrigerators and
freezers in UL 471 due to factors such as the difference in the room
sizes modeled for household versus retail appliances. Therefore,
building on the UL allowance of a 50-gram allowable leak limit and the
tests performed by the submitter, we concluded that the maximum charge
size should be 57 grams for the household refrigeration end-use.
    EPA did not receive specific information concerning the potential
energy efficiency effects of limiting the charge size to 57 g or less.
Thus, we are not able to judge the technical merits of the commenter's
statement.
    EPA does not have sufficient information supported by safety
testing data at this time from other commenters, industry, U.S.
national safety organizations, or non-governmental organizations to
support a charge size limit different from one based on UL 250, such as
the 150-gram limit in IEC 60335-2-24. EPA understands that the limit in
UL 250 may change in the future. If that occurs, and if the appropriate
safety testing data is submitted to EPA supporting safe use of a larger
charge, we would consider modifying the use conditions at a future
date.
    We acknowledge that a larger charge size may improve the energy
efficiency of an appliance and simplify its construction. However,
based on the analyses available at this time, we do not have sufficient
information to demonstrate that a larger charge size would not create
an unacceptable level of risk as compared to other available
substitutes in the household refrigeration end-use. As noted above, EPA
could modify the use conditions in the future if sufficient data were
submitted to support safe use of a larger charge size.
    Comment: One commenter requested a more precise definition of
``charge,'' recognizing that the exact value of the charge depends on
the accuracy of the charging equipment.
    Response: EPA regulations do not provide an accuracy specification
or interpretation for ``charge'' or ``charge size.'' EPA believes that
such a regulatory definition is not necessary for purposes of this use
condition. EPA believes that the wording in the use condition (``the
quantity of the substitute refrigerant'') provides sufficient guidance
and that manufacturers and service technicians have the proper
instrumentation and training to judge the quantity of refrigerant being
charged to an appliance.
    Comment: One commenter encouraged EPA to clarify or provide a test
procedure for how manufacturers should measure the potential solubility
of isobutane in the oil.
    Response: Providing such a test procedure is beyond the scope of
this final rule. The use conditions reflect the assumption that 7 grams
of a 57-gram charge could be solubilized in the refrigerant oil while
still allowing compliance with UL 250. The SNAP submittal for isobutane
in the household refrigeration end-use contains information on the
solubility of isobutane with refrigerant oils (GE, 2008). We typically
defer to the technical standard-setting agency on this type of issue
unless there is convincing evidence disputing such a calculation.
Moreover, we note that manufacturers that choose to use isobutane are
not obligated to measure its potential solubility in oil for purposes
of complying with the use conditions, since any charge below 50 grams
would be in compliance with UL 250 and the charge size limitations of
this rule. Thus we see no reason to establish a test procedure for
performing such an analysis.
    Comment: Two commenters observed that an appliance in the household
refrigeration end-use might incorporate more than one sealed system and
requested that the charge size limitation apply to each sealed system
in an appliance, not to the entire appliance.
    Response: EPA agrees and is clarifying that the 57-gram charge size
limit applies to each sealed system.\29\ A household refrigeration
appliance may incorporate multiple sealed systems. Having multiple
sealed systems is less of a concern than having a single system with
the same combined charge since the probability of two sealed systems
leaking simultaneously is very low. In addition, hermetically sealed
systems are less likely to leak, presenting a lower probability of fire
or explosion. Hermetically sealed systems provide an increased level of
safety in normal use.
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    \29\ A ``sealed system'' is an independently operated
refrigeration system, including a compressor, evaporator, condenser,
metering device, and refrigerant not shared for other purposes. For
example, a refrigerator-freezer might employ one sealed system to
chill food in the refrigerator section and a second sealed system to
keep food frozen in the freezer compartment. ``Appliance'' is
defined at 40 CFR 82.152 as ``any device which contains and uses a
refrigerant and which is used for household or commercial purposes,
including any air conditioner, refrigerator, chiller, or freezer.''
Thus a refrigerator, freezer, or combination refrigerator and
freezer, for example, may consist of two appliances provided that
the refrigerant in the first appliance (i.e., the first compressor,
condenser, evaporator, and metering device) does not mix with the
refrigerant in the second appliance (e.g., the second compressor,
condenser, evaporator, and metering device).
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E. Charge Size Limitation (Retail Food Refrigeration)

    EPA received seven sets of comments on its proposed charge size
limitation of 150 grams (5.3 ounces) for the retail food refrigeration
end-use. Six commenters supported the 150-gram limitation, although
some offered additional comments.
    Comment: One commenter recommended increasing the limit to 170
grams for three reasons: first, that EPA's 150-gram limit was
calculated based on a small European-sized kitchen and reflected a 20-
percent reduction from the LFL; second, that the proposed limit was
based on domestic refrigerator standards and misapplied to commercial
applications; and third, that the UL standard reflects 150 grams of
leakage and 20 grams that remains in the oil and does not leak.
    Response: EPA is finalizing the 150-gram charge size limit as
proposed for this end-use. This limit is more conservative than the UL
471 standard, which reflects a leak amount of 150 grams (i.e., not
counting refrigerant

solubilized in oil). Unlike the charge limit for the household
refrigeration end-use, the charge limit for the retail food
refrigeration end-use does not reflect an additional amount of
refrigerant assumed to be solubilized in the oil because SNAP
submitters did not include test data to support this information for
propane. UL 471 limits the amount of refrigerant leaked to 150 grams,
based on testing performed during the development of the UL 471
standard. The commenter provided no test data showing that 20 grams (or
some alternative amount) would be captured in the oil if the UL 471
standard were applied. Nor was there evidence that the leak assumptions
for the household refrigeration end-use (7 of 57 grams solubilized)
might apply proportionately to other equipment or other refrigerants.
Therefore, because EPA does not have a sufficient analytic basis to
derive a 170-gram charge size limit, EPA has no basis to support a
change to the 150-gram charge size limit we proposed for this end-use.
    Comment: Two commenters also observed that the IEC standards may be
revised upward in the future, and that EPA's limit should reflect such
changes.
    Response: The IEC charge size limit has not yet increased and EPA
cannot anticipate the timing or extent of such an increase. Further,
EPA has not received any information showing that a larger charge size
would ensure that propane would present risks in this end-use that are
lower than or comparable to risks from other potentially available
substitutes. If the IEC or UL standards are revised in the future or if
other information becomes available that would support a change in
charge size, an interested party could petition EPA to revise this
aspect of the use condition.
    Comment: Another commenter stated that appliances manufactured for
export should be allowed to have a larger charge size corresponding to
the charge size requirements that apply at the point of installation.
The commenter claims that prohibiting a larger charge size for export
would be a disadvantage for U.S. companies selling appliances overseas.
    Response: Under section 612 of the Clean Air Act, the SNAP program
is applicable to any person introducing a substitute into interstate
commerce. Interstate commerce is defined in 40 CFR 82.104(n) as:

    The distribution or transportation of any product between one
state, territory, possession or the District of Columbia, and
another state, territory, possession or the District of Columbia, or
the sale, use or manufacture of any product in more than one state,
territory, possession or the District of Columbia. The entry points
for which the product is introduced into interstate commerce are the
release of a product from the facility in which the product was
manufactured, the entry into a warehouse from which the domestic
manufacturer releases the product for sale or distribution, and at
the site of United States Customs clearance.

    This definition applies to any appliances produced in the U.S.,
including appliances that will be exported. Therefore EPA cannot
support the comment to apply different use conditions based on where an
appliance is being exported.
    Comment: One commenter observed that because an appliance might
have two or more independent refrigeration systems, EPA's charge size
limitation should apply to each refrigeration system in an appliance
and not to each appliance.
    Response: EPA received a similar comment with respect to the
household refrigeration end-use, as described in Section V.D above. As
was the case for the household refrigeration end-use, EPA agrees that
the charge size limitation for the retail food refrigeration end-use
should apply to each sealed system in an appliance. EPA is modifying
the wording of the use condition to reflect this clarification.

F. Labeling

    EPA received 11 sets of comments on its proposal to require that
``Danger'' and ``Caution'' labels be permanently attached at specified
locations on household and retail appliances using hydrocarbon
refrigerants. The proposed wording was identical to that of UL 250
Supplement SA (household refrigeration) and UL 471 Supplement SB
(retail food refrigeration), except that EPA proposed that the
lettering be \1/4\ inch (6.4 mm) rather than the \1/8\ inch (3.2 mm)
specified in the UL standards. Seven commenters expressed support for
the proposed labeling use conditions, including the lettering size.
    Comment: Two commenters stated that EPA and UL should require the
same print color and size. Another commenter supported the proposal
except for the language reflecting clause (a) in UL 471 (retail food
refrigeration) for evaporators that can be contacted by a consumer; the
comment stated that evaporators are never accessible to a customer in
units that are ``cold wall design.'' Finally, one commenter
specifically opposed use of the words ``Danger'' and ``Caution.'' The
commenter stated that equipment is safe if it meets UL standards, that
the words would scare consumers, and that service technicians know what
they are dealing with.
    Response: EPA is finalizing the labeling use condition as proposed
(with the exception of a minor technical correction to the wording of
one of the labels, described in Section VI below). EPA believes that
notification is necessary to alert technicians and personnel who
dispose of or recycle appliances that a refrigerant has the potential
to ignite if a sparking source is nearby. This is particularly true
during the years these products are first introduced into the market
because most technicians in the U.S., as well as those involved in the
disposal chain, are not yet familiar with flammable refrigerants.
    EPA consults with UL and other national safety standards as often
as possible, recognizing that the organizations differ in functions and
goals. With the exception of the lettering size, EPA is adopting label
wording and requirements that are identical to those in the UL 250 and
UL 471 standards. The UL standards include a requirement to label
evaporators in the retail end-use, and EPA is mirroring that
requirement, noting that even if a customer does not have access to the
labeled area, service technicians with such access still need to be
made aware that a flammable refrigerant is present.
    Regarding the lettering size, EPA continues to believe that it
would be difficult to see warning labels with the \1/8\-inch lettering
stipulated by UL 250 and UL 471. Three commenters specifically endorsed
the \1/4\-inch minimum height proposed, and EPA is finalizing that
requirement, making it easier for technicians, consumers, retail store-
owners, and emergency first responders to see the warning labels.

G. Color-Coded Hoses and Piping

    EPA received 11 sets of comments on its proposed requirement that
an appliance containing hydrocarbon refrigerants 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. The color would be required at all service ports
and where service puncturing or otherwise creating an opening from the
refrigerant circuit to the atmosphere would be expected to occur, and
would extend a minimum of 1 inch in both directions from such
locations. The proposed rule observed that no industry standard exists
for color-coded hoses or pipe for flammable refrigerants, and sought
comment on potential development of such a standard.

    Three commenters supported the proposed requirement. One of the
supporting commenters stated that EPA's use condition would also
suffice in lieu of an industry standard. Other commenters opposed
various aspects of the color-coding requirement.
    Comment: One commenter stated that mandatory color-coding would
impose a burdensome additional cost and is not a requirement under
international standards. A second commenter stated that color-coding
would be superfluous in light of the proposed labeling requirement. A
third commenter stated that leak testing requirements obviate the need
for color-coding. A fourth commenter identified several concerns: that
hose materials could be potentially incompatible with the paint used,
that the marking could be obscured by ice or insulation, and that paint
on heat exchange surfaces could change the thermal resistance and water
retention properties of the heat exchanger, affecting performance.
    Other commenters recommended a more precise interpretation of the
requirement to ensure that color-coding need only be provided where
beneficial and not in locations where system performance could be
hindered. One commenter observed that coloring all tubing would be
costly and that locations should be selected that do not present
problems for sealing of valves or for operational efficiency. Another
commenter suggested that since UL 471 already requires labels near the
compressor, coloring would only be necessary at discharge and charge
locations. The commenter further stated that self-contained units with
one compressor only need markings at two locations--at the filling tube
and after the filter dryer (in the flow direction)--because such units
only use one refrigerant and present no risk of mixing.
    Several commenters observed that an equally effective and less
costly option for some manufacturers might be to use a colored sleeve
or cap that must be forcibly removed in order to access the service
tube. If a manufacturer removed the sleeve or cap during service, a
similar replacement would be required.
    Response: EPA is finalizing a requirement to use red PMS
185 coloring on hoses and tubing. This is the same color
specified in AHRI Guideline N-2008, ``Assignment of Refrigerant
Container Colors,'' to identify containers of flammable refrigerant,
such as propane, isobutane, and R-441A (AHRI, 2008). The purpose of the
colored hoses and tubing in this case is to enable service technicians
to identify the use of a flammable refrigerant and to take additional
precautions (e.g., reducing the use of sparking equipment) as
appropriate to avert accidents, and particularly in the event that
labels are no longer legible. The air-conditioning and refrigeration
industry currently uses distinguishing colors to identify different
refrigerants. Likewise, distinguishing coloring is used elsewhere to
indicate an unusual and potentially dangerous situation, such as the
use of orange-insulated wires in hybrid electric vehicles. In the U.S.,
household and retail appliances contain various refrigerants and it is
not always clear what type of refrigerant an appliance uses.
    Since red coloring is understood to represent ``hot,'' ``stop,'' or
``danger,'' red coloring will provide technicians, consumers, and
emergency responders with an unambiguous signal that a potential hazard
is present. The labeling requirement discussed in Section V.F will
complement the color-coding requirement by providing a more precise
warning of the potential hazards and necessary precautions. Further, it
is possible that labels, particularly those on the outside of the
appliance, may fall off or become illegible over time; adding red
coloring on tubing inside the appliance provides additional assurance
that technicians will be aware that a flammable refrigerant is present.
    In response to concerns about the location of the color-coding, EPA
is modifying the language for this use condition to reflect its intent
more precisely. Instead of requiring PMS 185 coloration at all
locations ``through which the refrigerant passes,'' this final rule
requires coloration at locations ``through which the refrigerant is
serviced,'' as well as areas where service puncturing or otherwise
creating an opening from the refrigerant circuit to the atmosphere
might be expected. EPA is also clarifying the location and extent of
the coloring on the hose or process tube (if one exists).\30\ This does
not mean that the entire hose or process tube must be colored. Rather,
for process tubes the tube must be colored for at least one inch with
the red mark to extend from the compressor. This way, if the process
tube is cut for service, the red marking still remains after the tube
is welded back together. If further servicing would leave the colored
portion of the process tube less than 2.5 centimeters (1 inch) long, a
new process tube would be required, with the red marking as described
above. For other locations--for example, if a service port or
refrigerant access valve is added to the system \31\--the red mark must
extend at least 1 inch in all directions from the port or valve.
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    \30\ A process tube extends from the compressor and is used to
add or remove refrigerant. After refrigerant is added or removed,
the process tube is usually pinched to stop refrigerant flow and
then could be soldered to provide a long-lasting seal. The tube is
used as an access point for service technicians and does not serve
any refrigerant-flow or heat transfer purposes.
    \31\ The UL Standards referenced in this rule do not allow the
inclusion of service ports in finished products using flammable
refrigerants; however, the coloring use condition would still apply
if a service port or access valve were added after the product was
sold.
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    To clarify that the red coloring must always be present (not just
applied initially at installation), we are providing more specificity
in the language of the use condition than proposed. We are changing
``must be applied'' to ``must be present'' to correct any
misperceptions that once the coloring is initially placed (``applied'')
at a location, it need not be replaced if damaged or removed. The word
``present'' conveys that the red coloring must always be at the
specified location.
    EPA does not believe that this requirement will impose a burdensome
additional cost. The only commenter to raise this point did not provide
any information about what such costs might be and why the commenter
thought they would be burdensome. In this preamble we are clarifying
one aspect of flexibility that could mitigate potential cost concerns.
Specifically, EPA agrees with the commenters' observation that a
colored sleeve or cap could be equally effective and may offer a less
costly option for some manufacturers. The proposed rule specified the
type, location, and dimensions of the coloration but did not specify
the physical manner in which the tube should be colored. EPA believes
that the use of a sleeve or cap is consistent with this use condition
as long as the requirements of the use condition (use of PMS
185, location, and dimension) are met. However, in order to
remain in compliance with the use condition, a technician who removes a
sleeve during servicing is required to replace that sleeve on the
serviced tube with another. Allowing the use of a sleeve instead of
paint will also help alleviate the concern expressed by one commenter
over the potential incompatibility of red paint with hose materials.
    EPA recognizes that labeling is another way to provide warning of
the presence of a flammable refrigerant, and--as discussed in Section
V.F above--is finalizing a labeling requirement. However, since over
time labels can come off or become illegible, labeling should not be
the sole means of

alerting users and service technicians of the presence of a flammable
refrigerant.
    Comment: One commenter supported the proposed color-coding
requirement but pointed out that the American Academy of Ophthalmology
and the Centers for Disease Control and Prevention report that 8
percent of American males are color-blind, primarily in the colors
green and red, making the need for labels even more important.
    Response: The Agency recognizes that there is a color-blind
population. This is one reason to use both labeling and coloring to
signal that a flammable refrigerant is being used.

H. Unique Fittings

    EPA received 13 sets of comments on its proposed requirement that
appliances using isobutane or R-441A in household refrigeration and
propane in retail food refrigeration end-uses have service aperture
fittings that differ from fittings used in equipment or containers
using non-flammable refrigerant. The proposed rule defined ``differ''
to mean that either the diameter must differ by at least 1/16 inch or
the thread direction must be reversed (i.e., right-handed vs. left-
handed). The proposed rule specified that these different fittings must
be permanently affixed to the unit and may not be accessed with an
adaptor until the end-of-life of the unit.
    Comments: Twelve commenters opposed the proposed requirement for
various combinations of the following reasons: Adding fittings at the
time of manufacture is not appropriate for certain appliance types;
additional fittings presents an increased leak risk; the requirement
could be easily circumvented; the risk of cross-contamination is
overstated; international standards do not require unique fittings; and
the requirement would be inconsistent with UL standards. One commenter,
while neither supporting nor opposing the proposal, stated that if
unique fittings are installed they should require the use of special
tools to dissuade unauthorized personnel from opening the fittings.
    Response: EPA is persuaded by the comments opposing a use condition
to require unique fittings. The Agency is removing the requirement for
unique fittings from the list of use conditions and is instead
providing a recommendation for unique fittings in the ``Further
Information'' column of Appendix R. The following paragraphs describe
the comments and EPA's response in more detail.
    Comments: Most commenters interpreted the language of the proposed
requirement to mean that all appliances subject to this rule must be
manufactured with unique fittings, even appliances that would not
require servicing and thus would otherwise not need fittings. They
observed that household and retail appliances, whether they use
hydrocarbons or another type of refrigerant, typically are hermetically
sealed and are manufactured without maintenance fittings or service
valves. They pointed out that any service port with a mechanical
connection (such as a lock ring) presents a leak risk and that
requiring additional service ports for the purpose of installing unique
fittings would add to that risk. One commenter also observed that
equipment is highly sensitive to charge size and any leak could cause
malfunction or failure. (The commenter stated that in its past
experience, three-fourths of service calls were related to service
ports.) One commenter observed that the presence of service ports could
create incentives for untrained technicians to attempt servicing.
Another commenter pointed out that UL 250 and UL 471 prohibit
refrigerators or freezers that use a flammable refrigerant from
employing quick-connect fittings, flare fittings, compression fittings,
or packed stem valves.
    Response: EPA agrees with statements that a service valve installed
at the point of manufacture could increase the likelihood of leaks for
these types of appliances. We recognize from the comments that the
proposed requirement was worded in an overly broad manner. We intended
the requirement to apply only in cases where a service port or other
connection is installed subsequent to manufacture. EPA is aware that
the UL 250 and UL 471 standards forbid such ports at the time of
manufacture on units using flammable refrigerants. EPA recognizes that
service ports (whether with standard or unique fittings) are not
normally used in household refrigerators or stand-alone retail food
refrigerators and freezers.
    However, CAA 608(b)(2) requires all small appliances containing ODS
refrigerants to be equipped with service ports that allow for the
proper recovery of refrigerant during service or disposal of
refrigerators and freezers because service ports act as an access point
for recovery equipment. Under 40 CFR 82.154(a)(1), no refrigerant or
substitute may be knowingly vented unless otherwise exempted. For this
reason most hermetically sealed appliances are equipped with process
tubes that are used only for end-of-life recovery and which typically
do not leak.
    EPA does believe, however, that some hermetically sealed systems
eventually will be serviced and does not assume that such systems are
always completely leak-proof. Therefore EPA continues to believe that
if a service port or access valve is installed after manufacture, it
should employ a unique fitting that is maintained until the end-of-life
of the appliance.
    One commenter specifically supported a requirement for unique
fittings after the equipment is serviced and for the remainder of its
life. EPA believes that such fittings, if installed, should be designed
specifically for flammable refrigerants, such that those fittings would
not connect to service equipment designed for non-flammable
refrigerants.
    Comment: Several commenters observed that cross-contamination was
not a significant risk. Two commenters stated that requiring unique
fittings would not necessarily protect against cross-contamination. One
commenter stated that mixing of hydrocarbons and other refrigerants
would not pose a safety concern unless air or oxygen were present.
Another commenter asserted that since self-contained refrigerant
systems use only one refrigerant, there is no possibility that an
appliance would be refilled with an incorrect refrigerant. That
commenter also stated that proper refrigerant practices are in place
that require separate recovery cylinders for different refrigerants,
that technicians need only use one more type of cylinder, and that
economic incentives can foster proper recovery practices.
    Response: Overall, EPA disagrees with the comment that cross-