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EO_12866 SNAP HCs 2060-AP54 FRM 20111027.docx

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 82

[EPA-HQ-OAR-2009-0286; FRL-xxxx-x]

RIN 2060-AP54

Protection of Stratospheric Ozone: Listing of Substitutes for Ozone-Depleting Substances –

Hydrocarbon Refrigerants

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final Rule.

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 [INSERT DATE 60 DAYS AFTER PUBLICATION IN 

THE FEDERAL REGISTER]. The incorporation by reference of certain publications listed in the 

rule is approved by the Director of the Federal Register as of [INSERT DATE 60 DAYS AFTER 

PUBLICATION IN THE FEDERAL REGISTER].

ADDRESSES: EPA has established a docket for this action under Docket ID No. EPA-HQOAR-2009-0286. All documents in the docket are listed on the www.regulations.gov website.

Although listed in the index, some information is not publicly available, i.e., confidential business 
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information (CBI) or other information whose disclosure is restricted by statute. Certain other 

material, such as copyrighted material, is not posted on the website 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 (202) 566-1744, and the telephone number for the Air and Radiation Docket is 

(202) 566-1742.

FOR FURTHER INFORMATION CONTACT: Margaret Sheppard, Stratospheric Protection 

Division, Office of Atmospheric Programs, Mail Code 6205J, Environmental Protection Agency, 

1200 Pennsylvania Ave., NW, Washington, DC 20460; telephone number (202) 343-9163; fax 

number (202) 343-2338; e-mail address: sheppard.margaret@epa.gov. 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
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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
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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

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 

 

1 RTOC, 2010, pp. 50, 51, 64.
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into interstate commerce would be required to submit a new SNAP application under EPA 

regulations.2

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 

 

2 The submitter has informed EPA that that it is now marketing R-441A (the blend originally submitted as “HCR188C1”) under the trade name “HCR-188C.”
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designation R-441A under ASHRAE Standard 34-2010.3Throughout this final rule, we refer to 

that blend as R-441A.

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.

Figure 1. Refrigerant Safety Group Classification

Safety Group Increasin

g

Flam

mability

Higher Flammability A3 B3

Lower Flammability A2 B2

No Flame 

Propagation

A1 B1

Lower Toxicity Higher Toxicity

Increasing Toxicity

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°C and 101.3 kPa, and have either a lower flammability limit (LFL) of 

less than or equal to 0.10 kg/m3or a heat of combustion greater than or equal to 19,000 kJ/kg.

 

3

See Addendum g to Standard 34-2010.
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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.
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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

Category NAICS code or 

subsector

Description of regulated entities

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

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.”
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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

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

LFL–lower flammability limit

mg/l–milligrams per liter
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NAICS–North American Industrial Classification System

NARA–National Archives and Records Administration

NIOSH–U.S. National Institute for Occupational Safety and Health

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® 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

TSCA–Toxic Substances Control Act

TWA–time-weighted average

UL–Underwriters Laboratories Inc.

UMRA–Unfunded Mandates Reform Act

UNEP–United Nations Environment Programme
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VOC–volatile organic compound

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 
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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 
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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-users5. 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).

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 

 

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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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 
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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 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 website 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?
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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)-226in household refrigerators, freezers, and combination 

refrigerators and freezers.7(This preamble refers to HCR-188C1 as R-441A.)

EPA also proposed to list propane (R-290) as “acceptable, subject to use conditions,” as a 

substitute for CFC-12, HCFC-22, and R-5028in retail food refrigerators and freezers (stand-alone 

units only).

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 10

th edition of Underwriters Laboratories (UL) Standard UL 250 (household 

refrigeration end-use) or the 10th edition of Standard UL 471 (retail food refrigeration enduse).

 

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.

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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(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.
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(5) The refrigerator or freezer must have red, Pantone® 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)9of refrigerant.

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;

 

9 The proposed rule inadvertently represented 5 pounds as 2.8 kilograms instead of 2.3 kg, which is accurate.
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 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 industrywide 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 
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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 enduse). 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 
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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 
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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 
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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. 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.

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 
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less than 5 (A.S. Trust & Holdings, 2009),10 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 enduses (e.g., GWPs of HFC-134a, R-404A, and R-410A are approximately 1,430, 3,920, and 2,090, 

respectively).

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:

 

10 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).
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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. HC600a 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.11

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).

 

11 As a percent of annual VOC emissions in the U.S., this represents approximately 5x10-6

percent (for isobutane in 

the household food refrigeration end-use) (ICF, 2009a and ICF, 2011a), 5x10-6percent (for propane in the retail food 

refrigeration end-use) (ICF, 2009b and ICF, 2011b), and 3x10-7percent (for R-441A in the household food 

refrigeration end-use) (ICF, 2009d and ICF, 2011c).
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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)12 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.

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 

 

12 LFL is the minimum concentration in air at which flame propagation occurs.
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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
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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)13 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, 

 

13 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.
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provided in the docket, describe the toxicity impact assessments in more detail (ICF, 2009a; ICF, 

2009b; ICF, 2009d; ICF, 2011a, ICF, 2011b, ICF, 2011c).

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 
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hydrocarbon and compared them to each hydrocarbon’s reference concentration (RfC).

14 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.

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, 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 

 

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

health effects.
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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.
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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 
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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 
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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 shortcircuit, (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.
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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,
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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 5.1.2.7 and SA 5.1.3.6) 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 
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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:
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 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 UL 250, including Supplement SA 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.
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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
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that the LFL would not be reached near an ignition source in those locations.15 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.

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 R441A 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 

 

15 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. (SA5.1.2.7, SA5.1.3.6). 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.
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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 m3, 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).
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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 UL 250, including 

Supplement SA 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 UL 250 (particularly Supplement SA) have passed appropriate ignition or 

leakage tests as stipulated in the standard. Passing the leakage test (at SA 5.1.2.7 and SA 5.1.3.6) 
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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 x 10-13 on average, with a worst-case probability of 7.0 x 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 
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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 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 
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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 
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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)16 and the UL Standard for Commercial Refrigerators and 

Freezers, UL 471 (for the retail food refrigeration end-use).17 Most commenters supported 

adherence to applicable UL standards, although some offered the following additional comments.

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 Z21.24,18 ASHRAE Standard 15,19 UL

 

16 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.

17 EPA is referencing the UL Standard 471, 9th edition Supplement SB; “Requirements for Refrigerators and Freezers

18 American National Standards Institute (ANSI) Z21.24: Connectors for Gas Appliances.

19 ASHRAE Standard 15-2010: Safety Standard for Refrigeration Systems.
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Standard 21,20 EN 378,21 ISO-5149,22 the IOR Safety Code of Practice for Refrigerating Systems 

Utilising A2 & A3 Refrigerants,23 and AS/NZS 1677.24

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)

 

20 UL 21: Standard for LP-Gas Hose.

21 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).

22International Organization for Standardization. ISO 5149: Mechanical refrigerating systems used for cooling and heating --

Safety requirements.

23 IOR (Institute of Refrigeration) : Safety code of practice for refrigerating systems utilising A2 and A3 refrigerants

24 The Joint Australian/New Zealand ASNZS Standard 1677: Addresses safety, design, construction, installation, testing, 

inspection, operation and maintenance of refrigeration systems.
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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 
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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,25 and a charge 

of isobutane providing comparable cooling would be 40 to 50% of the charge of HFC-134a,26 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 

website 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.”27 

Thus, the safety record of hydrocarbon refrigerators and freezers in Europe appears to reflect 

experience primarily with charge sizes much smaller than 150 g.

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 

 

25 A. D. Little, 2002.

26 ACRIB, 2001.

27 Greenpeace, 1997.
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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 
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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.
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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.28 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.

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.

 

28 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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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.
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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 enduse, 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.
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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.
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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.
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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 
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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.
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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).29 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 system30- the red mark must extend at least 1 inch 

in all directions from the port or valve.

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.

 

29 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.

30 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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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 Pantone #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.
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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 nonflammable 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. lefthanded). 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.
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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. 
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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 crosscontamination. 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.
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Response: Overall, EPA disagrees with the comment that cross-contamination is unlikely. 

Depending on the type of equipment being serviced, and its typical servicing patterns, it is quite 

possible that refrigerants could be mixed, particularly where best practices are not employed. 

Currently, many different refrigerants are used in refrigerators and freezers. Technicians are likely 

to encounter numerous refrigerants – now including hydrocarbons - raising the possibility that 

flammable refrigerants could be mixed with non-flammable refrigerants or that flammable 

refrigerants could be added to an appliance designed for non-flammable refrigerants. Not only 

does the mixing of refrigerants pose a risk for the cooling system of the appliance, it also can limit 

reclamation options. Whereas – as observed by two commenters – pure refrigerants have market 

value, contaminated refrigerants are costly to re-purify into their individual refrigerant 

components, and costly to discard properly, raising the risk of illegal venting. Nevertheless, EPA 

agrees with the commenters that cross-contamination itself does not pose safety issues sufficient 

to warrant a mandatory requirement for unique fittings.

Comment: Several commenters observed that technicians could defeat the intent of the 

requirement by using other kinds of fittings after first service. One commenter stated that service 

technicians have the tools to bypass unique fittings and would do so rather than purchase 

additional gauges and line sets to service the small number of hydrocarbon refrigerators. Another 

stated that most small appliances do not have fittings (unique or otherwise) and that technicians 

and the public could use line-piercing fittings if needed.

Response: EPA understands that a requirement for unique fittings would not prevent illegal or 

improper efforts to service appliances if a technician were determined to do so. The “Further 

Information” section in the regulation recommends that only technicians specifically trained in 

handling flammable refrigerants service refrigerators and freezers containing these refrigerants, 
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and that technicians gain an understanding of minimizing the risk of fire and the steps to use 

flammable refrigerants safely. We note that, in addition to preventing the mixing of refrigerants, 

the proposed use condition was intended to reduce the risk of fire by ensuring that flammable 

refrigerants are used only in appliances designed for flammable refrigerants. The proposed use 

condition was intended to prevent a technician from inadvertently attempting to service a 

refrigerator as if it contained non-flammable refrigerant when it actually contained highly 

flammable hydrocarbon refrigerant, or vice versa.

Comment: Four commenters stated that education is the best tool to prevent refrigerant 

contamination. One suggested creating a nationwide training program; the other, which 

specializes in training, observed that training had proven to be an effective option in lieu of a 

previous proposal to require unique fittings for high-pressure HFC refrigerants.

Response: EPA supports the concept of a national training program for flammable refrigerants 

and welcomes industry efforts to educate technicians on proper refrigerant use and proper service 

and disposal practices.

I. Small Containers

EPA received nine comments on the proposed use condition to limit the sale of the 

hydrocarbon refrigerants in containers designed to hold less than five pounds (2.3 kg).

31 This 

requirement was intended to prevent purchase by untrained people who lack the skills or 

equipment necessary to recover and charge refrigerant properly. Six commenters supported the 

proposed requirement. Other comments are discussed below.

 

31 As mentioned previously, the proposed rule inadvertently represented 5 pounds as 2.8 kilograms instead of 2.3 kg, 

which is accurate
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Comment: Three commenters opposed this requirement, stating that a small-container sales 

restriction was not the appropriate vehicle to compel proper training. One observed that properly

trained technicians know how to handle refrigerants safely; another noted that the proposed rule 

protections, such as labeling, would help mitigate the potential risk associated with technician 

error; and the third observed that untrained customers can already buy camping gas, which is a 

flammable gas like isobutane.

In addition, one of the commenters opposing the requirement stated that it would pose 

practicality and logistics problems for its service network for household refrigerators. The 

commenter stated that a five-pound minimum requirement would result in the transport of more

combustibles in a service vehicle than needed and that it would be preferable to use “right-sizing” 

canisters containing the exact charge for the particular appliance to ensure efficient and accurate 

service, to minimize the load a technician needs to carry, and to prevent under- and over-charging.

Response: After considering the comments received, EPA is removing the small-container 

sales restriction from the use conditions. EPA agrees that requiring the sale of the three 

hydrocarbon refrigerants in containers of at least five pounds could cause the transport of an 

unnecessary amount of refrigerant and increase risks to service technicians and – in the event of a 

vehicular accident – to others on the road. EPA intended the proposed use condition to prevent or 

minimize the purchase of refrigerant by untrained people who would not have the appropriate 

skills or equipment to properly recover or charge the refrigerant. However, after considering the 

comments, EPA recognizes that an unintended consequence of restricting smaller-container sales 

is the prospect that appliance owners could purchase non-refrigerant-grade propane such as 

camping gas to service their equipment. Non-refrigerant-grade hydrocarbons could contain 

contaminants that might fail to be absorbed by a filter drier, mix with the oil and cause high wear 
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on compressor bearings, or clog heat exchangers and capillary tubes. Such events could lead to 

equipment failure, increased servicing need, and more potential emissions of the refrigerant. 

These effects could increase risk to the appliance owner, service technicians, and those involved 

in appliance disposal.

As discussed in Section K of this preamble, EPA agrees with the importance of having 

hydrocarbon refrigerants handled only by trained technicians. The listing decisions for these three 

refrigerants in Appendix R to 40 CFR, part 82, subpart G, provide a recommendation that only

technicians specifically trained in handling flammable refrigerants service refrigerators and 

freezers containing these refrigerants. We also include a recommendation that technicians gain an 

understanding of minimizing the risk of fire and the steps to use flammable refrigerants safely.

J. Use of Hydrocarbon Refrigerants in Other End-uses

Comment: Three commenters requested that isobutane and propane be considered for use in 

both the household refrigeration and retail food refrigeration end-uses. Six other commenters 

specifically requested that isobutane be allowed for use in retail food refrigeration. All of these 

commenters reasoned that both refrigerants have similar physical characteristics (e.g., 

flammability limits, toxicity profiles, handling practices, safety group classification) and that the 

UL 250 and UL 471 standards do not distinguish between them.

Response: EPA is finalizing acceptability determinations only for the substitutes and end-uses 

identified in submissions to the Agency and in the proposed rule: isobutane and R-441A in the 

household refrigeration end-use, and propane in the retail food refrigeration end-use. The 

submitters did not request review of isobutane or R-441A in the retail food refrigeration end-use, 

or propane in the household refrigeration end-use, so EPA did not review those substitutes for 

those end-uses in this rulemaking. 
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The SNAP regulations at 40 CFR part 82, subpart G establish a process for the submission 

and review of SNAP applications and the finalization of acceptability determinations. EPA makes 

a listing determination after evaluation of the substitute. EPA follows a notice-and-comment 

rulemaking process to list substitutes that are proposed as acceptable subject to use conditions, 

acceptable subject to narrowed use limits, or unacceptable. Although EPA can issue SNAP 

determinations for substitutes and end-uses that were not provided by an applicant, the Agency

must perform the same detailed analysis, based on the criteria described in the SNAP regulations. 

EPA would need to make a risk screen available to the public through the notice-and-comment 

rulemaking process before making a listing decision. If EPA were to find those substitutes 

acceptable in those specific end-uses, use conditions would probably be necessary.

We recognize the stakeholders’ interest in using isobutane in the retail food refrigeration enduse and propane in the household refrigeration end-use. Preliminary information supports the 

observations that the use profiles and handling practices for these chemicals in these end-uses are 

very similar to the combinations of substitutes and end-uses being finalized today. EPA may

consider a subsequent rulemaking addressing the use of isobutane and R-441A in the retail food 

refrigeration end-use, and propane in the household refrigeration end-use.

Comment: One commenter noted that it did not have sufficient information on HCR-188C and 

HCR-188C1 (i.e., R-441A) to recommend their approval for the retail food refrigeration end-use. 

The commenter stated, however, that if ASHRAE Standard 34 were to classify those hydrocarbon 

blends as A3 refrigerants then the argument could be made that they should be listed in both enduses.

Response: In February 2011, ASHRAE issued Addendum g to Standard 34-2010, classifying 

R-441A as an A3 refrigerant. We agree that an applicant may be able to support a petition to find 
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R-441A acceptable subject to use conditions in the retail food refrigeration end-use based on our 

current understanding that R-441A has characteristics that are similar to those of propane. 

However, we do not currently have the appropriate technical demonstrations before us to propose, 

much less finalize, such a determination. If in the future a person submits a petition supported by 

a technical demonstration, we could take rulemaking action on such a listing.

K. Training

EPA received eight comments in response to its discussion of training in the preamble of the 

proposed rule. All acknowledged the value of training.

Comment: One commenter recommended against a mandatory national training program, 

observing that in the European Union, where hydrocarbon refrigerants are more prevalent, there is 

no national training program and each manufacturer handles training on its own. Another 

commenter, a training organization for technicians, suggested that training be a required element 

of a federal certification of technicians. The commenter noted that EPA intends to update the “test 

bank” of test questions for technician certification under CAA section 608, and so the Agency

should recognize the merits of incorporating hydrocarbon refrigerants into existing programs. 

This commenter stated that without a recertification program, hundreds of thousands of 

technicians will not see the new test questions. Therefore the commenter suggested that EPA 

either create another “type” category of certification under CAA section 608 addressing 

flammable refrigerants and/or require recertification of technicians every five years because of 

new refrigerants. One commenter stated that EPA should strongly consider delaying any SNAP 

acceptability listing for isobutane until such a program can be developed and deployed industrywide. The commenter observed that this could take two years and increase costs to consumers.
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Response: EPA agrees that training is an important way for technicians to learn about the safe 

handling of flammable refrigerants. We recognize that there are some long-standing training 

programs on flammable refrigerants in other countries where hydrocarbon refrigerants are 

currently in wide use. We also recognize that the use of hydrocarbon refrigerants, and training on 

such use, is in its infancy in the U.S., and is generally tied directly to specific products or 

applications, rather than generally to multiple types of products. 

Since the inception of the SNAP program and the section 608 refrigerant management 

program, we have continued to list a variety of new refrigerants as acceptable. EPA has not 

previously required that certified technicians be recertified as a result of the listing of the 

additional refrigerants. Moreover, the goals of the section 608 technician certification program 

reflect the need to reduce emissions during servicing, maintenance, repair and disposal. They do 

not substitute for the proper training that is normally provided through trade schools, 

apprenticeships, or other industry mechanisms. Given the extent of technical knowledge available 

within the industry, we believe that industry is better equipped than EPA to define the specific 

contents of such training, and that it is not necessary for EPA to require training in order for 

newly listed refrigerants to be used as safely as other refrigerants currently available.

Although we have determined not to require training as a use condition for these substitutes to 

ensure that they can be used as safely as other available refrigerants, we recommend that 

technicians receive training on the safe handling of hydrocarbon refrigerants through avenues 

such as industry-sponsored national training programs.

L. Other Options Considered
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EPA considered, and sought comment on, several other options or related issues in the 

proposed rule, although we did not propose them. This section describes comments the Agency

received on those options.

1. Use only in appliances specific to OEMs. EPA sought comment on an option that would 

allow isobutane and propane as a refrigerant for use only in OEM-specific appliances, as 

described in a SNAP application. The reason for such a limitation would be the concern that 

appliances from other manufacturers would not be designed with spark-proof engineering; nor 

would the manufacturers be able to develop recovery equipment compatible with flammable 

refrigerants.

Comment: EPA received two comments supporting EPA’s approach to not impose such a 

limitation. One observed that limiting use to SNAP-reviewed equipment would be timeconsuming and costly for all parties involved, with little added health and safety benefit. 

Response: EPA agrees that limiting refrigerant use to SNAP-reviewed equipment would be 

time-consuming and costly for all parties involved. We believe that adherence to the UL standards 

and the use conditions in this rule will help ensure that equipment is designed to use these 

refrigerants safely, and that use of these substitutes will present risks that are lower than or 

comparable to the risks from other potential substitutes. Thus we believe it is not necessary to 

include such a limitation.

2. Recovery equipment. EPA observed that it had considered proposing a use condition 

requiring that recovery equipment used to recapture flammable refrigerants be compatible with 

flammable refrigerants, and sought information on whether there currently is an industry standard 

for recovery units for flammable refrigerants and whether specific recovery units are available 

that are compatible with the refrigerants addressed in today’s rule.
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Comment: One commenter stated a belief that there are no known manufacturers of recovery

equipment for hydrocarbon refrigerants. Another commenter stated that recovery equipment used 

to recover flammable refrigerants must be compatible with flammable refrigerants, and in the 

absence of an industry standard, it has developed its own service equipment designed to recapture 

a flammable refrigerant in accordance with federal and state regulations. A third commenter 

observed that recovery units are only used in countries like the U.S. where venting is not allowed. 

Finally, one commenter observed that it uses a recovery device in its U.S. test market that is 

specifically designed for use with flammable refrigerants.

Response: The availability of recovery equipment is not necessary to ensure that the 

refrigerant will not pose more risk than other available substitutes in this end-use. EPA will 

continue to assess the need for, and availability of, recovery equipment that is compatible with 

flammable refrigerants.

3. Venting prohibition. EPA sought comment on whether, in a future rulemaking, it should 

consider exempting hydrocarbon refrigerants from the section 608 venting prohibition.

Comment: Several commenters expressed varying levels of support for exempting 

hydrocarbon refrigerants from the venting prohibition. Two commenters expressed unequivocal 

support, and four stated that they would support such an exemption if EPA were to confirm there 

would be no health impact. Another commenter asserted that venting would pose little 

environmental impact, comparing the worst-case scenario release of 150 grams from retail food 

refrigeration end-uses, or 57 grams from household refrigeration end-uses, to one and one-third 

pound, respectively, of CO2 equivalent. Another commenter stated that isobutane is not 

dangerous, but should not be vented in enclosed spaces. Another commenter supported a venting 

exemption during servicing, but advocated recovery at end-of-life due to environmental risks 
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associated with the release of refrigerant and oil captured in the refrigerant. Finally, a commenter 

stated that the environmental impact from venting such small charges is minimal and that safety 

concerns could be better mitigated through a properly designed and executed educational 

program. One commenter expressed reservations about allowing venting, and recommended 

further assessment of flammability risks as well as the potential risk associated with the release of 

synthetic refrigerant oil during venting.

Response: EPA appreciates the information provided by commenters. Venting is addressed by

section 608 of the CAA and EPA will develop a separate rule under that authority if we determine

that hydrocarbon refrigerants in the household refrigeration and retail food refrigeration end-uses

should be exempted from the venting prohibition. EPA exercised such authority to exempt 

hydrocarbons used in industrial process refrigeration systems from the venting prohibition (see 69 

FR 11946), but has not made a similar determination for hydrocarbons used in household and 

retail food refrigerators and freezers. Currently, EPA’s regulations implementing section 608 at 

subpart F to 40 CFR part 82 would prohibit venting of isobutane, propane, and R-441A 

refrigerants during service, maintenance, repair, and disposal from the end-uses considered in this 

rule.

4. Requiring only one use condition. EPA sought comment on an approach that it considered 

(but did not propose): to require that the only use condition for each hydrocarbon refrigerant be to 

meet applicable UL 250 and UL 471 standards.

Comment: EPA received one comment, which opposed such a provision.

Response: As described above, and consistent with the proposal, EPA has not limited the use 

conditions to compliance with the UL standards. 
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5. “Unacceptable” finding pending industry-wide servicing standards. EPA sought comment 

on (but did not propose) finding hydrocarbon refrigerants unacceptable until an industry-wide 

standard exists for servicing appliances using hydrocarbon refrigerants.

Comment: EPA received two comments on this issue, one opposing and one supporting. 

Neither commenter provided a rationale for its recommendation. 

Response: As described elsewhere, and consistent with the proposal, EPA is finding the three 

hydrocarbon refrigerants acceptable subject to use conditions. 

M. Other Comments on Proposed Rule

Comment: In a comment unrelated to the specifics of the proposed rule, one commenter 

recommended consideration of the type of automated system it uses on its production line. This 

system sounds a pre-warning alarm when 20 percent of the LFL is reached and shuts down the 

system if 40 percent of the LFL is reached. The commenter noted that this system conforms to the 

European standard and is approved by TUV (Technischer Überwachungs-Verein (Technical 

Inspection Association)), a German safety monitoring agency.

Response: EPA does not believe it is necessary to establish a use condition requiring the type 

of system suggested by the commenter. OSHA addresses the use of flammable substances in the 

workplace, including through its regulations at 29 CFR 1910.106, as discussed in response to 

other comments below. To the extent a manufacturer believes that additional precautions are 

appropriate, we believe the manufacturer is in the best position to determine how to address the 

risks of installing a hydrocarbon refrigerant considering the specific characteristics of its

production facilities and personnel. We note that in addition to OSHA requirements, other forces 

such as concerns for liability; costs of fire and casualty insurance; and reputational interests may

also dictate a firm’s behavior with respect to worker health and safety protections. 
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This final rule includes, in the “Further Information” column of Appendix R, 

recommendations that OEMs institute safety precautions as needed in their facilities to address 

potential hazards in the production of appliances using hydrocarbon refrigerants. EPA notes that 

OSHA regulations are in place to address such hazards. The table in Appendix M references 

OSHA requirements at 29 CFR part 1910, including those at 29 CFR 1910.106 (flammable and 

combustible liquids), 1910.110 (storage and handling of liquefied petroleum gases), and 

1910.1000 (toxic and hazardous substances). Nothing in these final listing decisions, including the 

“Further Information” column, supersedes other regulations such as these OSHA requirements.

Comment: Another commenter recommended that the use conditions in the final rule address 

the use of an odorant as a warning agent to alert manufacturing personnel or technicians of the 

presence of a leak. Without recommending how the issue should be addressed in this final rule, 

the commenter offered the following observations:

 Technicians or manufacturers may use mercaptan as an odor warning agent;

 Mercaptan is corrosive and is removed by filters and driers in refrigeration systems;

 Refrigerant classification standards for Australia and New Zealand require that Group A3 

refrigerants be odorized or subject to alternative safety provisions.

Response: EPA agrees that odorization is one way to alert manufacturing or servicing 

personnel of the presence of a hydrocarbon refrigerant. EPA’s risk screen did not evaluate these 

refrigerants with the addition of an odorant, nor did our proposed rule address odorants in its 

discussion of refrigerant composition or in its proposed use conditions. Today’s final rule does 

not prohibit the introduction of an odorant into isobutane, propane, or R-441A refrigerant as long 

as the refrigerant remains within purity specifications. The use conditions in today’s final rule, 
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such as red coloring and adherence to UL standards, provide ample safeguards to alert 

manufacturers, service personnel, and customers of the presence of a flammable refrigerant.

VI. What Other Changes Is EPA Making in the Final Rule?

In addition to changes made in response to comments, as described in Section V above, EPA 

is making the following minor changes:

A. Propane as Substitute for R-502

EPA is revising the wording in the Appendix R table to correct a typographical error. As 

discussed above, this final rule lists propane as acceptable subject to use conditions as a substitute 

for CFC-12, HCFC-22, and R-502 in the retail food refrigeration end-use. In the NPRM, the 

proposed Appendix R table erroneously omitted R-502 (a blend of HCFC-22 and CFC-115) from 

the listing, although it was included in the preamble discussion. This final rule corrects the error 

by including R-502 as one of the refrigerants for which propane is listed as a substitute in the 

retail food refrigeration end-use.

B. Wording of Use Conditions for Labeling

The use conditions in the proposed rule included requirements for marking (e.g., labeling) of 

appliances using isobutane and HCR-188C1 (i.e., R-441A) in the household refrigeration end-use, 

and propane in the retail food refrigeration end-use. EPA intended that language to mirror that of 

the UL standards. We are making two minor changes to this requirement.

First, we are restructuring the language for the requirement. The language of the proposed rule

first listed the wording required for five different types of labels, and then described where each 

of the labels was to be placed. For the final rule, we have moved the location requirements, so 

they are specified immediately before the corresponding label wording. EPA believes this minor 
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revision in the regulatory language provides more clarity and makes the use condition easier to 

implement.

Second, EPA is making a minor technical correction to the wording of one of the labels. In the 

proposed rule, one of the labels was to read as follows:

“(b) Near the machine compartment: "DANGER- Risk of Fire or Explosion. Flammable 

Refrigerant Used. Do Not Use Mechanical Devices. To Be Repaired Only By Trained Service 

Personnel. Do Not Puncture Refrigerant Tubing."

The phrase “Do Not Use Mechanical Devices” was included erroneously in the proposed 

requirement. EPA recognizes that trained personnel may need to use mechanical devices to 

service the machine compartment. We have removed that phrase from the use condition in the 

final listing decision, making the condition consistent with the UL 250 and UL 471 requirements. 

C. “Further Information” Column in Listing Decisions

EPA is also modifying the recommendations listed under “Further Information” to more 

appropriately cross-reference existing OSHA regulations and to avoid confusion about the 

relationship between EPA and OSHA requirements. 

The proposed rule contained, under “Further Information,” the following recommendations:

 Technicians and equipment manufactures should wear appropriate personal protective 

equipment, including chemical goggles and protective gloves when handling 

isobutane, HCR-188C, and HCR-188C1. Special care should be taken to avoid contact 

with the skin since isobutane, HCR-188C, and HCR-188C1 like many refrigerants, can 

cause freeze burns on the skin. 

 A class B dry powder type fire extinguisher should be kept nearby.
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 Proper ventilation should be maintained at all times during the manufacture of 

appliances containing hydrocarbon refrigerant through adherence to good 

manufacturing practices as per 29 CFR 1910.110.32 If refrigerant levels in the air 

surrounding the equipment rise above one-fourth of the lower flammability limit, the 

space should be evacuated, and re-entry should only occur after the space has been 

properly ventilated.

 Technicians should only use spark-proof tools when working refrigerators and freezers 

with R-600a, HCR-188C, and HCR-188C1.

 Recovery equipment designed for flammable refrigerants should be used.

 Only technicians specifically trained in handling flammable refrigerants should service 

refrigerators and freezers containing these refrigerants. Technicians should gain an 

understanding of minimizing the risk of fire and the steps to use flammable 

refrigerants safely.

 In production facilities or other facilities where large quantities of the refrigerant 

would be stored, proper safety precautions should be in place to minimize the risk of 

explosion. These facilities should be equipped with proper ventilation systems to 

minimize the risks of explosion and should be properly designed and operated to 

reduce possible ignition sources.

 Room occupants should evacuate the space immediately following the accidental 

release of this refrigerant.

 

32 OSHA regulations at 29 CFR 1910.110 consider ventilation adequate “when the concentration of the gas in a gasair mixture does not exceed 25 percent of the lower flammable limit.”
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The Agency did not receive any comments on these recommendations. EPA believes that they

are appropriate and that they serve as useful reminders of safe practices for technicians and 

manufacturers. EPA recognizes that some of these recommendations are reflected in OSHA 

regulations for worker health and safety. For this reason, EPA is adding a cross-reference to 

OSHA regulations at 29 CFR part 1910 (Occupational Health and Safety Standards) in order to 

ensure that regulated entities are aware of these requirements. Specifically, Appendix R provides 

a cross-reference to 29 CFR 1910.106 (flammable and combustible liquids), 1910.110 (storage 

and handling of liquefied petroleum gases), 1910.157 (portable fire extinguishers), and 1910.1000 

(toxic and hazardous substances).

VII. Statutory and Executive Order Reviews

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

Improving Regulation and Regulatory Review

Under Executive Order 12866 (58 FR 51735, October 4, 1993), this action is a "significant 

regulatory action.” It raises novel legal or policy issues arising out of legal mandates, the 

President's priorities, or the principles set forth in the Executive Order. Accordingly, EPA 

submitted this action to the Office of Management and Budget (OMB) for review under 

Executive Orders 12866 and 13563 (76 FR 3821, January 21, 2011) and any changes made in 

response to OMB recommendations have been documented in the docket for this action.

B. Paperwork Reduction Act

This action does not impose any new information collection burden. This final rule is an 

Agency determination. It contains no new requirements for reporting. The Office of Management 

and Budget (OMB) has previously approved the information collection requirements contained in 

the existing regulations in subpart G of 40 CFR part 82 under the provisions of the Paperwork 
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Reduction Act, 44 U.S.C. 3501 et seq. and has assigned OMB control number 2060-0226. This 

Information Collection Request (ICR) included five types of respondent reporting and 

recordkeeping activities pursuant to SNAP regulations: submission of a SNAP petition, filing a 

SNAP/TSCA Addendum, notification for test marketing activity, recordkeeping for substitutes 

acceptable subject to use restrictions, and recordkeeping for small-volume uses. The OMB control 

numbers for EPA's regulations are listed in 40 CFR part 9 and 48 CFR Chapter 15.C. 

C. Regulatory Flexibility Act

The Regulatory Flexibility Act (RFA) generally requires an agency to prepare a regulatory 

flexibility analysis of any rule subject to notice and comment rulemaking requirements under the 

Administrative Procedure Act or any other statute unless the agency certifies that the rule will not 

have a significant economic impact on a substantial number of small entities. Small entities 

include small businesses, small organizations, and small governmental jurisdictions. For purposes 

of assessing the impacts of this rule on small entities, small entity is defined as: (1) A small 

business as defined by Small Business Administration regulations at 13 CFR 121.201; (2) a small 

governmental jurisdiction that is a government of a city, county, town, school district or special 

district with a population of less than 50,000; and (3) a small organization that is any not-forprofit enterprise which is independently owned and operated and is not dominant in its field.

After considering the economic impacts of this final rule on small entities, I certify that this 

action will not have a significant economic impact on a substantial number of small entities. In

determining whether a rule has a significant economic impact on a substantial number of small 

entities, the impact of concern is any significant adverse economic impact on small entities, since 

the primary purpose of the regulatory flexibility analyses is to identify and address regulatory

alternatives “which minimize any significant economic impact of the rule on small entities.” 5 
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U.S.C. 603 and 604. Thus, an agency may certify that a rule will not have a significant economic 

impact on a substantial number of small entities if the rule relieves regulatory burden, or 

otherwise has a positive economic effect on all of the small entities subject to the rule. The 

requirements of this final rule affect the manufacturers of household refrigerators and freezers and 

retail food refrigerators and freezers. Today’s action allows users the additional options of using 

isobutane, propane, and R-441A, but does not mandate such use. Because isobutane, propane, and 

R-441A refrigeration systems are not yet manufactured in the U.S. (with the exception of limited 

test-marketing), and because the final rule actually imposes fewer requirements than the proposed 

rule (i.e., removal of the unique fittings requirement), manufacturers would not be required to 

change business practices to meet the use conditions and thus the rule would not impose any new 

costs on small entities. 

D. Unfunded Mandates Reform Act

This action contains no Federal mandates under the provisions of Title II of the Unfunded 

Mandate Reform Act of 1995 (UMRA), 2 U.S.C. 1531-1538 for State, local, or tribal 

governments or the private sector. This action imposes no enforceable duty on any State, local, or 

tribal governments or the private sector. 

The enforceable requirements of this final rule related to integrating risk mitigation devices, 

markings, and procedures for maintaining the safety of household refrigerators and freezers and 

retail food refrigerators and freezers using hydrocarbon refrigerants affect only small number of 

manufacturers of these appliances and their technicians. This rule provides additional refrigerant 

options, allowing greater flexibility for industry in designing consumer products. Further, since 

appliances using hydrocarbon refrigerants are not yet widely produced in the U.S., we do not 

expect impacts on existing users. Thus this rule is not subject to the requirements of sections 202 
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or 205 of the UMRA. This action is also not subject to the requirements of section 203 of UMRA 

because it contains no regulatory requirements that might significantly or uniquely affect small 

governments. This regulation applies directly to facilities that use these substances and not to 

governmental entities. The finding of “acceptability subject to use conditions” for isobutane, 

propane, and R-441A does not impact the private sector because manufacturers are not producing 

systems under the current regulation. This final rule does not mandate a switch to these 

substitutes; consequently, there is no direct economic impact on entities from this rulemaking.

E. Executive Order 13132: Federalism

This action does not have federalism implications. It will not have substantial direct effects on 

the States, on the relationship between the national government and the States, or on the 

distribution of power and responsibilities among the various levels of government, as specified in 

Executive Order 13132. This regulation applies directly to facilities that use these substances and 

not to governmental entities. Thus Executive Order 13132 does not apply to this action. 

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

This action does not have tribal implications, as specified in Executive Order 13175 (65 FR 

67249, November 9, 2000). It will not have substantial direct effects on tribal governments, on the 

relationship between the Federal government and Indian tribes, or on the distribution of power 

and responsibilities between the Federal government and Indian tribes, as specified in Executive 

Order 13175. Thus, Executive Order 13175 does not apply to this action.

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

This action is not subject to Executive Order 13045 (62 FR 19885, April 23, 1997) because it 

is not economically significant as defined in Executive Order 12866, and because the Agency

does not believe the environmental health or safety risks addressed by this action present a 
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disproportionate risk to children. This final rule provides both regulatory restrictions and 

recommended guidelines based upon risk screens conducted in order to reduce risk of fire and 

explosion.

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

This action is not a “significant energy action” as defined in Executive Order 13211 (66 FR 

28355 (May 22, 2001)) because it is not likely to have a significant adverse effect on the supply, 

distribution, or use of energy. Preliminary information indicates that appliances using these 

hydrocarbon refrigerants may be more energy-efficient than currently available systems in some 

climates. Therefore, we have concluded that this rule is not likely to have any adverse energy

effects.

I. National Technology Transfer and Advancement Act

Section 12(d) of the National Technology Transfer and Advancement Act of 1995 

(“NTTAA”), Pub L. No. 104-113, (15 U.S.C. 272 note) directs EPA to use voluntary consensus 

standards in its regulatory activities unless to do so would be inconsistent with applicable law or 

otherwise impractical. Voluntary consensus standards are technical standards (e.g., materials 

specifications, test methods, sampling procedures, and business practices) that are developed or 

adopted by voluntary consensus standards bodies. The NTTAA directs EPA to provide Congress, 

through OMB, explanations when the Agency decides not to use available and applicable 

voluntary consensus standards. 

This final rule involves incorporation by reference of technical standards issued by 

Underwriters Laboratories (UL) concerning the safety and reliability of flammable refrigerants. 

UL standards are voluntary consensus standards. The use conditions in the rule require, for the 

household refrigeration end-use, adherence to the UL Standard for Household Refrigerators and 
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Freezers, UL 250, 10th edition, 1993, updated August 2000. The use conditions also require, for 

the retail food refrigeration end-use, adherence to the UL Standard for Commercial Refrigerators 

and Freezers, UL 471, 10th edition, November 2010. Copies of UL 250 and UL 471 may be 

purchased at http://ulstandardsinfonet.ul.com/.

J. Executive Order 12898: Federal Actions to Address Environmental Justice in Minority

Populations and Low-Income Populations

Executive Order 12898 (59 FR 7629 (Feb. 16, 1994)) establishes federal executive policy on 

environmental justice. Its main provision directs federal agencies, to the greatest extent 

practicable and permitted by law, to make environmental justice part of their mission by

identifying and addressing, as appropriate, disproportionately high and adverse human health or 

environmental effects of their programs, policies, and activities on minority populations and lowincome populations in the United States. 

EPA has determined that this final rule will not have disproportionately high and adverse 

human health or environmental effects on minority or low-income populations because it 

increases the level of environmental protection for all affected populations without having any 

disproportionately high and adverse human health or environmental effects on any population, 

including any minority or low-income population. This final rule would allow sale of appliances 

with refrigerant substitutes that have no ODP and low GWPs. The reduction in ODS and GHG

emissions would assist in restoring the stratospheric ozone layer and provide climate benefits. 

K. Congressional Review Act

The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the Small Business 

Regulatory Enforcement Fairness Act of 1996, generally provides that before a rule may take 

effect, the agency promulgating the rule must submit a rule report, which includes a copy of the 
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rule, to each House of the Congress and to the Comptroller General of the United States. EPA will 

submit a report containing this rule and other required information to the U.S. Senate, the U.S. 

House of Representatives, and the Comptroller General of the United States prior to publication 

of the rule in the Federal Register. A major rule cannot take effect until 60 days after it is 

published in the Federal Register.

This action is not a ‘‘major rule’’ as defined by 5 U.S.C. 804(2). This rule will be effective 

[INSERT DATE 60 DAYS AFTER PUBLICATION IN THE FEDERAL REGISTER].

VIII. References

This preamble references the following documents, which are also in the Air and Radiation 

Docket at the address listed in Section I.B.1. Unless specified otherwise, all documents are 

available electronically through the Federal Docket Management System, Docket # EPA-HQOAR-2009-0286.

ACRIB, 2001. Guidelines for the Use of Hydrocarbon Refrigerants in Static Refrigeration 

and Air Conditioning Systems. Air Conditioning and Refrigeration Industry Board. 2001.

A.D. Little, 1991. Risk Assessment of Flammable Refrigerants for Use in Home Appliances

(draft report). Arthur D. Little, Inc., for EPA, Division of Global Change. September 10, 1991. 

Docket item EPA-HQ-OAR-2009-0286-0023.

A.D. Little, 2002. Global Comparative Analysis of HFC and Alternative Technologies for 

Refrigeration, Air Conditioning, Foam, Solvent, Aerosol Propellant, and Fire Protection 

Applications. Final Report to the Alliance for Responsible Atmospheric Policy, March 21, 2002.

Available online at http://www.arap.org/adlittle/4.html. Accessed on October 13, 2011.

AHRI, 2008. Air-Conditioning, Heating, and Refrigeration Institute, AHRI Guideline N-2008: 

Assignment of Refrigerant Colors. 2008.
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ASHRAE, 2010. American National Standards Institute (ANSI)/American Society of Heating, 

Refrigerating and Air-Conditioning Engineers (ASHRAE). Standard 34-2010: Designation and 

Safety Classification of Refrigerants. 2010. (Supersedes ANSI/ASHRAE Standard 34-2007.)

A.S. Trust & Holdings, Inc., 2007. Significant New Alternatives Policy Program Submission 

to the United States Environmental Protection Agency. June 2007.

A.S. Trust & Holdings, Inc., 2009. HCR-188C New Composition. Follow-up to the HCR188C Significant New Alternatives Policy Program Submission to the United States

Environmental Protection Agency. August 2009.

Ben and Jerry’s, 2008. Ben and Jerry’s/Unilever, Significant New Alternatives Policy

Program Submission to the United States Environmental Protection Agency, October 2008.

EPA, 1994. Significant New Alternatives Policy Technical Background Document: Risk 

Screen on the Use of Substitutes for Class I Ozone-Depleting Substances: Refrigeration and Air 

Conditioning. Stratospheric Protection Division. March, 1994.

GE, 2008. Significant New Alternatives Policy Program Submission to the United States 

Environmental Protection Agency, October 2008.

Greenpeace, 1997. “Greenfreeze A Revolution in Domestic Refrigeration.” Available online 

at http://archive.greenpeace.org/ozone/greenfreeze/. Accessed on October 13, 2011.

ICF, 1997. ICF Consulting. Physiological Effects of Alternative Fire Protection Agents -

Hypoxic Atmospheres Conference. Stephanie Skaggs prepared the proceedings of the conference 

held May 22, 1997 in New London, CT.
*** E.O. 12866 Review –Revised– Do Not Cite, Quote, or Release During Review***

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ICF, 2009a. ICF Consulting. “Significant New Alternatives Policy Program - Refrigeration 

and Air Conditioning Sector – Risk Screen on Substitutes for CFC-12 in Household Refrigerators 

and Household Freezers – Substitute: Isobutane.” May 22, 2009.

ICF, 2009b. ICF Consulting. “Significant New Alternatives Policy Program - Refrigeration 

and Air Conditioning Sector – Risk Screen on Substitutes for CFC-12, HCFC-22, and R502 in 

Retail Food Refrigeration – Substitute: Propane.” May 26, 2009.

ICF, 2009c. ICF Consulting. “Significant New Alternatives Policy Program in the Household 

Refrigeration Sector – Risk Screen on Substitutes for CFC-12 and HCFC-22 in Household 

Refrigerators, Freezers and Window AC Units – Substitute: HCR-188C.” July 17, 2009.

ICF, 2009d. ICF Consulting. “Significant New Alternatives Policy Program – Refrigeration 

and Air Conditioning Sector – Risk Screen on Substitutes for CFC-12 and HCFC-22 in 

Household Refrigerators and Freezers– Substitute: HCR-188C1.” November 6, 2009.

ICF, 2011a. ICF Consulting. “Significant New Alternatives Policy Program Refrigeration and 

Air Conditioning Sector – Risk Screen on Substitutes for CFC-12 and HCFC-22 in Household 

Refrigerators and Household Freezers – Substitute: Isobutane.” June 2011.

ICF, 2011b. ICF Consulting. “Significant New Alternatives Policy Program Refrigeration and 

Air Conditioning Sector – Risk Screen on Substitutes for CFC-12, HCFC-22 and R502 in Retail 

Food Refrigeration – Substitute: Propane.” June 2011.

ICF, 2011c. ICF Consulting. “Significant New Alternatives Policy Program in the Household 

Refrigeration Sector – Risk Screen on Substitutes for CFC-12 and HCFC-22 in Household 

Refrigerators and Freezers– Substitute: R-441.” June 2011.

ICF, 2011d. ICF Consulting. “Additional end-use modeling for household refrigerators and 

freezers.” July 2011.
*** E.O. 12866 Review –Revised– Do Not Cite, Quote, or Release During Review***

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IPCC/TEAP, 2005. Safeguarding the Ozone Layer and the Global Climate System: Special 

Report of the Intergovernmental Panel on Climate Change. Edited by Bert Metz, Lambert 

Kuijpers, Susan Solomon, Stephen O. Andersen, Ogunlade Davidson, Jose Pons, David de Jager, 

Tahl Kestin, Martin Manning and Leo Meyer. Cambridge University Press. 2005. Available 

online at: http://www.ipcc.ch/pdf/special-reports/sroc/sroc_full.pdf

Murray, D.M. 1997. “Residential House and Zone Volumes in the United States: Empirical 

and Estimated Parametric Distributions.” Risk Analysis. 17(4): 439-446.

ORNL, 1997. J. Sand, S. Fischer, and V. Baxter, “Energy and Global Warming Impacts of 

HFC Refrigerants and Emerging Technologies,” 1997, Oak Ridge National Lab.

RTOC, 2010. The 2010 Report of the United Nations Environment Programme (UNEP)’s 

Refrigeration, Air Conditioning and Heat Pumps Technical Options Committee (RTOC). 

Available online at http://ozone.unep.org/teap/Reports/RTOC/RTOC-Assessment-report2010.pdf.

TEAP, 2010. United Nations Environment Programme. Report of the Technology and 

Economic Assessment Panel. Available online at 

http://ozone.unep.org/teap/Reports/TEAP_Reports/teap-2010-progress-report-volume2-

May2010.pdf

Underwriters Laboratories (UL), 2000. UL 250: Household Refrigerators and Freezers. 10th 

edition. Supplement SA: Requirements for Refrigerators and Freezers Employing a Flammable 

Refrigerant in the Refrigerating System. Underwriters Laboratories, Inc. August 25, 2000.

Underwriters Laboratories (UL), 2010. UL 471. Commercial Refrigerators and Freezers. 10th 

edition. Supplement SB: Requirements for Refrigerators and Freezers Employing a Flammable 

Refrigerant in the Refrigerating System. Underwriters Laboratories, Inc. November 24, 2010.
*** E.O. 12866 Review –Revised– Do Not Cite, Quote, or Release During Review***

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World Meteorological Organization (WMO), 2011. WMO Scientific Assessment of Ozone 

Depletion: 2010. Available online at 

http://ozone.unep.org/Assessment_Panels/SAP/Scientific_Assessment_2010/index.shtml.
*** E.O. 12866 Review –Revised– Do Not Cite, Quote, or Release During Review***

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Protection of Stratospheric Ozone: Listing of Substitutes for Ozone-Depleting Substances–

Hydrocarbon Refrigerants

Final Rule

Page 90 of 96 pages

List of Subjects in 40 CFR part 82

Environmental protection, Administrative practice and procedure, Air pollution control, 

Incorporation by reference, Reporting and recordkeeping requirements

Date: _____________________________________________

___________________________________________________

Lisa P. Jackson, 

Administrator.
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For the reasons set out in the preamble, EPA is amending 40 CFR part 82 as follows:

PART 82 - PROTECTION OF STRATOSPHERIC OZONE

1. The authority citation for part 82 continues to read as follows:

Authority: 42 U.S.C. 7414, 7601, 7671 - 7671q.

Subpart G – Significant New Alternatives Policy Program

2. Subpart G is amended by adding Appendix R to read as follows:

Appendix R to subpart G of part 82- Substitutes Subject to Use Restrictions Listed in the [DATE 

OF PUBLICATION IN THE FEDERAL REGISTER] final rule, Effective [INSERT DATE 60 

DAYS AFTER PUBLICATION IN THE FEDERAL REGISTER].
*** E.O. 12866 Review –Revised– Do Not Cite, Quote, or Release During Review***

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SUBSTITUTES THAT ARE ACCEPTABLE SUBJECT TO USE CONDITIONS

End-use Substitute Decision Use Conditions Further Information

Household 

refrigerators,

freezers, and 

combination 

refrigerators 

and freezers

(New 

equipment 

only)

Isobutane (R600a) as a 

substitute for 

CFC-12 and 

HCFC-22

R-441A as a 

substitute for 

CFC-12 and 

HCFC-22

Acceptable 

Subject To 

Use 

Conditions 

These refrigerants may be used only in new 

equipment designed specifically and 

clearly identified for the refrigerant (i.e., 

none of these substitutes may be used as a 

conversion or “retrofit” refrigerant for 

existing equipment designed for a different 

refrigerant).

These refrigerants may be used only in a 

refrigerator or freezer, or combination 

refrigerator and freezer, that meets all 

requirements listed in Supplement SA to 

the 10th edition of the Underwriters 

Laboratories (UL) Standard for Household 

Refrigerators and Freezers, UL 250, dated 

1993 updated August 2000. In cases where 

the final rule includes requirements more 

stringent than those of the 10th edition of 

UL 250, the appliance must meet the 

requirements of the final rule in place of 

the requirements in the UL Standard.

The quantity of the substitute refrigerant (i.e., 

“charge size”) shall not exceed 57 grams 

(2.0 ounces) in any refrigerator, freezer, or 

combination refrigerator and freezer for 

each circuit. 

Applicable OSHA requirements at 29 CFR 

part 1910 must be followed, including 

those at 29 CFR 1910.106 (flammable 

and combustible liquids), 1910.110 

(storage and handling of liquefied 

petroleum gases), 1910.157 (portable 

fire extinguishers), and 1910.1000 (toxic 

and hazardous substances).

Proper ventilation should be maintained at 

all times during the manufacture and 

storage of equipment containing 

hydrocarbon refrigerants through 

adherence to good manufacturing 

practices as per 29 CFR 1910.106. If 

refrigerant levels in the air surrounding 

the equipment rise above one-fourth of 

the lower flammability limit, the space 

should be evacuated and re-entry should 

occur only after the space has been 

properly ventilated.

Technicians and equipment manufacturers 

should wear appropriate personal 

protective equipment, including 

chemical goggles and protective gloves, 

when handling isobutane and R-441A. 

Special care should be taken to avoid 

contact with the skin since these 

refrigerants, like many refrigerants, can 

cause freeze burns on the skin. 

A class B dry powder type fire extinguisher 

should be kept nearby.

Technicians should only use spark-proof 

tools when working on refrigerators and 

freezers with isobutane and R-441A.

Recovery equipment designed for 

flammable refrigerants should be used.

Only technicians specifically trained in 

handling flammable refrigerants should 

service refrigerators and freezers 

containing these refrigerants.

Technicians should gain an 

understanding of minimizing the risk of 

fire and the steps to use flammable 

refrigerants safely.
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End-use Substitute Decision Use Conditions Further Information

Household 

refrigerators, 

freezers, and 

combination 

refrigerators 

and freezers

(New 

equipment 

only)

Isobutane (R600a) as a 

substitute for 

CFC-12 and 

HCFC-22

R-441A as a 

substitute for 

CFC-12 and 

HCFC-22

Acceptable 

Subject To 

Use 

Conditions 

As provided in clauses SA6.1.1 and 

SA6.1.2 of UL Standard 250, the 

following markings shall be attached at 

the locations provided and shall be 

permanent: 

(a) On or near any evaporators that can 

be contacted by the consumer: 

"DANGER- Risk of Fire or Explosion. 

Flammable Refrigerant Used. Do Not 

Use Mechanical Devices To Defrost 

Refrigerator. Do Not Puncture 

Refrigerant Tubing."

(b) Near the machine compartment: 

"DANGER- Risk of Fire or Explosion. 

Flammable Refrigerant Used. To Be 

Repaired Only By Trained Service 

Personnel. Do Not Puncture Refrigerant 

Tubing."

(c) Near the machine compartment: 

“CAUTION - Risk of Fire or Explosion. 

Flammable Refrigerant Used. Consult 

Repair Manual/Owner's Guide Before 

Attempting To Service This Product. All 

Safety Precautions Must be Followed."

(d) On the exterior of the refrigerator: 

“CAUTION - Risk of Fire or Explosion. 

Dispose of Properly In Accordance With 

Federal Or Local Regulations. 

Flammable Refrigerant Used."

(e) Near any and all exposed refrigerant 

tubing: “CAUTION - Risk of Fire or 

Explosion Due To Puncture Of 

Refrigerant Tubing; Follow Handling 

Instructions Carefully. Flammable 

Refrigerant Used."

All of these markings shall be in letters 

no less than 6.4 mm (1/4 inch) high. 

The refrigerator, freezer, or combination 

refrigerator and freezer must have red, 

Pantone® Matching System (PMS) 

#185 marked pipes, hoses, or other 

devices through which the refrigerant is 

serviced (typically known as the service 

port) to indicate the use of a flammable 

refrigerant. This color must be present at 

all service ports and where service 

puncturing or otherwise creating an 

opening from the refrigerant circuit to 

the atmosphere might be expected (e.g., 

process tubes). The color mark must 

extend at least 2.5 centimeters (1 inch) 

from the compressor and must be 

replaced if removed.

Room occupants should evacuate the 

space immediately following the

accidental release of this refrigerant.

If a service port is added then household 

refrigerators, freezers, and combination 

refrigerator and freezers using these 

refrigerants should have service aperture 

fittings that differ from fittings used in 

equipment or containers using nonflammable refrigerant. “Differ” means 

that either the diameter differs by at least 

1/16 inch or the thread direction is 

reversed (i.e., right-handed vs. lefthanded). These different fittings should 

be permanently affixed to the unit at the 

point of service and maintained until the 

end-of-life of the unit, and should not be 

accessed with an adaptor.
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End-use Substitute Decision Use Conditions Further Information

Retail food 

refrigerators 

and freezers 

(stand-alone 

units only)

(New 

equipment 

only)

Propane (R290) as a 

substitute for 

CFC-12, 

HCFC-22, 

and R-502

Acceptable 

subject to 

use 

conditions

These refrigerants may be used only in 

new equipment specifically designed 

and clearly identified for the 

refrigerants (i.e., none of these 

substitutes may be used as a 

conversion or “retrofit” refrigerant 

for existing equipment designed for 

other refrigerants).

These substitutes may only be used in 

equipment that meets all 

requirements in Supplement SB to 

the 10th edition of the Underwriters 

Laboratories (UL) Standard for 

Commercial Refrigerators and 

Freezers, UL 471, dated November 

2010. In cases where the final rule 

includes requirements more stringent 

than those of the 10th edition of UL 

471, the appliance must meet the

requirements of the final rule in 

place of the requirements in the UL 

Standard.

The charge size for the retail food 

refrigerator or freezer shall not 

exceed 150 grams (5.3 ounces) in 

each circuit.

Applicable OSHA requirements at 29 

CFR part 1910 must be followed, 

including those at 29 CFR 1910.94 

(ventilation) and 1910.106 

(flammable and combustible liquids), 

1910.110 (storage and handling of 

liquefied petroleum gases), and 

1910.1000 (toxic and hazardous 

substances).

Proper ventilation should be maintained 

at all times during the manufacture 

and storage of equipment containing 

hydrocarbon refrigerants through 

adherence to good manufacturing 

practices as per 29 CFR 1910.106. If 

refrigerant levels in the air 

surrounding the equipment rise above 

one-fourth of the lower flammability 

limit, the space should be evacuated 

and re-entry should occur only after 

the space has been properly 

ventilated.

Technicians and equipment 

manufacturers should wear 

appropriate personal protective 

equipment, including chemical 

goggles and protective gloves, when 

handling propane. Special care should 

be taken to avoid contact with the 

skin since propane, like many 

refrigerants, can cause freeze burns 

on the skin. 

A class B dry powder type fire 

extinguisher should be kept nearby.

Technicians should only use spark-proof 

tools when working on refrigerators 

and freezers with propane.

Recovery equipment designed for 

flammable refrigerants should be 

used.

Only technicians specifically trained in 

handling flammable refrigerants 

should service refrigerators and 

freezers containing these refrigerants.

Technicians should gain an 

understanding of minimizing the risk 

of fire and the steps to use flammable 

refrigerants safely.

Note: In accordance with the limitations provided in section 310(a) of the Clean Air Act (42 U.S.C. 7610(a)), nothing in this table 

shall affect the Occupational Safety and Health Administrations’ authority to promulgate and enforce standards and other 

requirements under the Occupational Safety and Health Act of 1970 (29 U.S.C. 651 et seq.)
*** E.O. 12866 Review –Revised– Do Not Cite, Quote, or Release During Review***

95 of 96

End-use Substitute Decision Use Conditions Further Information

Retail food 

refrigerators 

and freezers 

(stand-alone 

units only)

(New 

equipment 

only)

Propane (R290) as a 

substitute for 

CFC-12, 

HCFC-22, 

and R-502

Acceptable 

subject to 

use 

conditions

As provided in clauses SB6.1.2 to SB6.1.5 

of UL Standard 471, the following 

markings shall be attached at the 

locations provided and shall be 

permanent:

(a) Attach on or near any evaporators that 

can be contacted by the consumer: 

"DANGER- Risk of Fire or Explosion. 

Flammable Refrigerant Used. Do Not 

Use Mechanical Devices To Defrost 

Refrigerator. Do Not Puncture 

Refrigerant Tubing."

(b) Attach near the machine compartment: 

"DANGER- Risk of Fire or Explosion. 

Flammable Refrigerant Used. To Be 

Repaired Only By Trained Service 

Personnel. Do Not Puncture 

Refrigerant Tubing."

(c) Attach near the machine compartment: 

“CAUTION - Risk of Fire or 

Explosion. Flammable Refrigerant 

Used. Consult Repair Manual/Owner's 

Guide Before Attempting To Service 

This Product. All Safety Precautions 

Must be Followed."

(d) Attach on the exterior of the 

refrigerator: “CAUTION - Risk of Fire 

or Explosion. Dispose of Properly In 

Accordance With Federal Or Local 

Regulations. Flammable Refrigerant 

Used."

(e) Attach near any and all exposed 

refrigerant tubing: “CAUTION - Risk 

of Fire or Explosion Due To Puncture 

Of Refrigerant Tubing; Follow 

Handling Instructions Carefully. 

Flammable Refrigerant Used."

All of these markings shall be in letters no 

less than 6.4 mm (1/4 inch) high. 

The refrigerator or freezer must have red, 

Pantone® Matching System (PMS) 

#185 marked pipes, hoses, and other 

devices through which the refrigerant 

is serviced, typically known as the 

service port, to indicate the use of a 

flammable refrigerant. This color must 

be present at all service ports and 

where service puncturing or otherwise 

creating an opening from the 

refrigerant circuit to the atmosphere 

might be expected (e.g., process tubes). 

The color mark must extend at least 2.5 

centimeters (1 inch) from the 

compressor and must be replaced if 

removed.

Room occupants should evacuate the 

space immediately following the 

accidental release of this 

refrigerant.

If a service port is added then 

household refrigerators, freezers, 

and combination refrigerator and 

freezers using these refrigerants 

should have service aperture 

fittings that differ from fittings 

used in equipment or containers 

using non-flammable refrigerant. 

“Differ” means that either the 

diameter differs by at least 1/16 

inch or the thread direction is 

reversed (i.e., right-handed vs. lefthanded). These different fittings 

should be permanently affixed to 

the unit at the point of service and 

maintained until the end-of-life of 

the unit, and should not be accessed 

with an adaptor.
*** E.O. 12866 Review –Revised– Do Not Cite, Quote, or Release During Review***

96 of 96

Note: The use conditions in this appendix contain references to certain standards from Underwriters Laboratories Inc. (UL). 

The standards are incorporated by reference, and the referenced sections are made part of the regulations in part 82:

1. UL 250: Household Refrigerators and Freezers. 10th edition. Supplement SA: Requirements for Refrigerators and Freezers 

Employing a Flammable Refrigerant in the Refrigerating System. Underwriters Laboratories, Inc. August 25, 2000.

2. UL 471. Commercial Refrigerators and Freezers. 10th edition. Supplement SB: Requirements for Refrigerators and 

Freezers Employing a Flammable Refrigerant in the Refrigerating System. Underwriters Laboratories, Inc. November 24, 2010.

The Director of the Federal Register approves this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR 

part 51. Copies of UL Standards 250 and 471 may be purchased at http://ulstandardsinfonet.ul.com/.

You may inspect a copy at U.S. EPA’s Air and Radiation Docket; EPA West Building, Room 3334, 1301 Constitution Ave., 

N.W., Washington DC or at the National Archives and Records Administration (NARA). For questions regarding access to these 

standards, the telephone number of EPA’s Air and Radiation Docket is 202-566-1742. For information on the availability of this 

material at NARA, call 202-741-6030, or go to: 

http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

[FR Doc. ]