local or Tribal governments or the private sector.

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.

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

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

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

    This action is not subject to Executive Order 13045 because it is
not economically significant as defined in Executive Order 12866, and
because EPA does not believe the environmental health or safety risks
addressed by this action present a disproportionate risk to children.
While EPA has not conducted a separate analysis of risks to infants and
children associated with this rule, the rule does contain use
conditions that would reduce exposure risks to the general population,
with the reduction of exposure being most important to the most
sensitive individuals. This action's health and risk assessments are
contained in the comparisons of toxicity for the various substitutes,
as well as in the risk screens for the substitutes that are listed in
this rule. The risk screens are in the docket for this rulemaking.

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

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

I. National Technology Transfer and Advancement Act and 1 CFR Part 51

    This action involves technical standards. EPA has decided to use
and incorporate by reference three technical safety standards in the
use conditions for the types of refrigeration and air conditioning
equipment addressed in this action: two standards developed by UL and
one developed by ASHRAE.
    EPA incorporates by reference the 2019 edition of UL Standard
60335-2-40, which establishes requirements for the evaluation of
commercial and residential AC and dehumidifier equipment and safe use
of flammable refrigerants, among other things. Additionally, EPA uses
and incorporates by reference the 2021 edition of UL Standard 61010-2-
011, which establishes requirements for the evaluation of laboratory
equipment and safe use of flammable refrigerants, among other things.
These standards are discussed in greater detail in sections II.E and
II.F.4 of this preamble.
    The 2019 UL Standard 60335-2-40 and 2021 UL Standard 61010-2-011
are available at http://www.shopulstandards.com/ProductDetail.aspx?UniqueKey=36463 and may be purchased by mail at:
COMM 2000, 151 Eastern Avenue, Bensenville, IL 60106; Email:
[email protected]; phone: 1-888-853-3503 in the U.S. or Canada
(other countries dial 1-415-352-2178); website: http://ulstandards.ul.com/ or www.comm-2000.com. The cost of each of the 2019
UL Standard 60335-2-40 and 2021 UL Standard 61010-2-011 is $440 for an
electronic copy and $550 for hardcopy. UL also offers a subscription
service to the Standards Certification Customer Library that allows
unlimited access to their standards and related documents. The cost of
obtaining this standard is not a significant financial burden for
equipment manufacturers and purchase is not necessary for those
selling, installing, and servicing the equipment. Therefore, EPA
concludes that the UL standards incorporated by reference is reasonably
available.
    EPA is also incorporating by reference ANSI/ASHRAE Standard 15-
2019,

Safety Standard for Refrigeration Systems, in the use conditions for
six refrigerants listed for use in chillers. This standard concerns the
safe design, construction, installation, and operation of refrigeration
systems. This standard is available at https://www.ashrae.org/resources-publications/bookstore/standards-15-34 and may be purchased
by mail at: 6300 Interfirst Drive, Ann Arbor, MI 48108; by phone: 1-
800-527-4723 in the U.S. or Canada; website: http://www.techstreet.com/ashrae/ashrae_standards.html?ashrae_auth_token=. The cost of ASHRAE
Standard 15-2019 is $159.00 for an electronic copy or hardcopy. The
cost of obtaining this standard is not a significant financial burden
for equipment manufacturers or for those selling, installing and
servicing the equipment. Therefore, EPA concludes that the ASHRAE
standard incorporated by reference is reasonably available.
    EPA is incorporating by reference the following addenda to ANSI/
ASHRAE Standard 15-2019, available at https://www.ashrae.org/technical-resources/standards-and-guidelines/standards-addenda:
     Addendum a, ANSI-approved February 6, 2020, concerning
updates to providing capacity factors for overpressure protection and
introducing a method for calculating pressure relief capacity factors
for refrigerants not included in the standard.
     Addendum b, ANSI-approved February 6, 2020, concerning
updates to the definition of ``listed,'' and adding the term
``labeled.''
     Addendum c, ANSI-approved September 1, 2020, concerning
updates to allow the use of equipment using small amounts of non-A1
refrigerants if they are listed to appropriate safety standards.
     Addendum d, ANSI-approved April 29, 2022, concerning
clarification that the standard does not apply to residential
refrigeration systems.
     Addendum e, ANSI-approved January 27, 2022, concerning
revisions to requirements related to refrigerant piping.
     Addendum f, ANSI-approved September 30, 2020, concerning
the addition of a new appendix providing clarifying, nonmandatory
information, movement of mandatory information into the body of the
standard, and updates to references.
     Addendum i, ANSI-approved July 31, 2020, concerning the
modification of the standard by deferring regulation of ammonia
refrigeration to ANSI/IIAR 2 and removal of erroneous references to
ammonia.
     Addendum j, ANSI-approved October 30, 2020, concerning the
replacement of the terms ``flammable'' and ``nonflammable'' with the
specific refrigerant class.
     Addendum k, ANSI-approved October 30, 2020, concerning the
modification of the existing listing requirement in the standard by
clarifying the acceptable product safety listing standards.
     Addendum m, ANSI-approved June 30, 2022, concerning the
modification of allowances for the use of mechanical ventilation to
expand this mitigation strategy for human comfort applications using
A2L refrigerants, helping to harmonize the standard with UL 60335-2-40,
3rd Edition.
     Addendum n, ANSI-approved May 31, 2022, concerning the
address of a continuous maintenance proposal to clarify wording about
airflow face velocity.
     Addendum o, ANSI-approved April 29, 2022, concerning the
clarification of notification requirements.
     Addendum q, ANSI-approved May 31, 2022, concerning the
modification of requirements for mechanical ventilation in machinery
rooms using only 2L classified refrigerants, updates to the graphical
method for determining required ventilation rates, and addition of an
alternate calculation method for compliance.
     Addendum r, ANSI-approved May 31, 2022, concerning the
modification of the definition of machinery rooms.
    EPA has already incorporated the following standards into appendix
R: UL 471 (November 24, 2010); UL 484 (December 21, 2007, with changes
through August 3, 2012); UL 541 (December 30, 2011); and UL 60335-2-24
(April 28, 2017).

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

    Executive Order 12898 (59 FR 7629, February 16, 1994) 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 (people of color and/or Indigenous
peoples) and low-income populations.
    EPA believes that the human health or environmental conditions that
exist prior to this action result in or have the potential to result in
disproportionate and adverse human health or environmental effects on
people of color, low-income populations and/or indigenous peoples. This
action's health and environmental risk assessments are contained in the
comparison of health and environmental risks for HFC-32, HFO-1234yf, R-
452B, R-454A, R-454B, R-454C, R-1150, 2-BTP, EXXFIRE[supreg], and
Powdered Aerosol H, as well as in the risk screens that are available
in the docket for this rulemaking. EPA's analysis indicates that other
environmental impacts and human health impacts of HFC-32, HFO-1234yf,
R-452B, R-454A, R-454B, R-454C, R-1150, 2-BTP, EXXFIRE[supreg], and
Powdered Aerosol H are comparable to or less than those of other
substitutes that are listed as acceptable for the same end-use. Because
adoption of the new substitutes listed in this final rule is voluntary,
the Agency is unable to quantify when, where, and how much of the
listed substitutes will be produced and used. Thus, EPA cannot
determine the extent to which this rule will exacerbate or reduce
existing disproportionate adverse effects on communities of color and
low-income people as specified in Executive Order 12898 (59 FR 7629,
February 16, 1994).
    EPA believes that it is not practicable to assess whether this
action is likely to result in new disproportionate and adverse effects
on people of color, low-income populations and/or indigenous peoples.
However, the listings for HFC-32, HFO-1234yf, R-452B, R-454A, R-454B,
R-454C, R-1150, 2-BTP, EXXFIRE[supreg], and Powdered Aerosol H in the
end-uses addressed in this action provide additional lower-GWP and ODP
or comparable alternatives in their respective end-uses. By providing
lower-GWP and ODP or comparable alternatives for these end-uses, this
rule is anticipated to reduce the use and eventual emissions of potent
greenhouse gases in these end-uses, which could help to reduce the
effects of climate change, including the public health and welfare
effects on people of color, communities of low-income and/or Indigenous
peoples. The Agency will continue to evaluate the impacts of this
program on communities with environmental justice concerns and consider
further action, as appropriate.

K. Congressional Review Act (CRA)

    This action is subject to the CRA, and EPA will submit a rule
report to each House of the Congress and to the Comptroller General of
the United States. This action is not a ``major rule'' as defined by 5
U.S.C. 804(2).

IV. References

    Unless specified otherwise, all documents are available
electronically through the Federal Docket Management System at https://www.regulations.gov, Docket number EPA-HQ-OAR-2021-0836.

ASHRAE, 2019a. ANSI/ASHRAE Standard 34-2019: Designation and Safety
Classification of Refrigerants.
ASHRAE, 2019b. ANSI/ASHRAE Standard 15-2019: Safety Standard for
Refrigeration Systems. 2019.
Chemical and Engineering News, 2020. ``CFC replacements are a source
of persistent organic pollution in the Arctic.'' Katherine Bourzac.
May 21, 2020. Available online at: https://cen.acs.org/environment/persistent-pollutants/CFC-replacements-source-persistent-organic/98/web/2020/05.
David et al., 2021. ``Trifluoroacetic acid deposition from emissions
of HFO-1234yf in India, China, and the Middle East,'' Volume 21,
issue 19. Atmos. Chem. Phys., 21, 14833-14849, 2021. https://doi.org/10.5194/acp-21-14833-2021. Available online at https://
acp.copernicus.org/articles/21/14833/2021/.
``Environmental effects of stratospheric ozone depletion, UV
radiation, and interactions with climate change: UNEP Environmental
Efects Assessment Panel, Update 2020.'' Photochemical &
Photobiological Sciences Available online at: https://ozone.unep.org/sites/default/files/assessment_panels/EEAP-summary-update-2021-for-policymakers.pdf.
EEAP, 2021. Environmental Effects of Stratospheric Ozone Depletion,
UV Radiation, and Interactions with Climate Change: UNEP
Environmental Effects Assessment Panel, Update 2021. Available
online at: https://ozone.unep.org/sites/default/files/assessment_panels/EEAP-summary-update-2021-for-policymakers.pdf.
Engineering ToolBox, 2005. Refrigerants--Physical Properties.
Available online at: https://www.engineeringtoolbox.com/refrigerants-d_902.html Accessed October 28, 2021.
EPA, 2004. A Guide to Completing a Risk Screen: Collection and Use
of Risk Screen Data. Fire Suppression Sector. April 2004.
Freeling et al., 2020. Finnian Freeling, David Behringer, Felix
Heydel, Marco Scheurer, Thomas A. Ternes, and Karsten N[ouml]dler.
``Trifluoroacetate in Precipitation: Deriving a Benchmark Data Set''
Environ. Sci. Technol. 2020, 54, 18, 11210-11219. August 17, 2020.
Available online at https://pubs.acs.org/doi/10.1021/acs.est.0c02910.
Freeling et al., 2022. Finnian Freeling, Marco Scheurer, Jan
Koschorreck, Gabriele Hoffmann, Thomas A. Ternes, and Karsten
N[ouml]dler. ``Levels and Temporal Trends of Trifluoroacetate (TFA)
in Archived Plants: Evidence for Increasing Emissions of Gaseous TFA
Precursors over the Last Decades,'' Environ. Sci. Technol. Lett.
2022, 9, 5, 400-405. April 18, 2022. Available online at: https://pubs.acs.org/doi/10.1021/acs.estlett.2c00164.
Hodnebrog, et al., 2013. Hodnebrog, [Oslash]., Etminan, M.,
Fuglestvedt, J.S., Marston, G., Myhre, G., Nielsen, C.J., Shine,
K.P., and Wallington, T.J. (2013). Global Warming Potentials and
Radiative Efficiencies of Halocarbons and Related Compounds: A
Comprehensive Review, Reviews of Geophysics, 51, 300-378. Available
online at doi.org/10.1002/rog.20013.
ICF, 2014. Assessment of the Potential Impact of Hydrocarbon
Refrigerants on Ground Level Ozone Concentrations. February 2014.
ICF, 2022a. Risk Screen on Substitutes in Chillers and Industrial
Process Air Conditioning (New Equipment); Substitute: R-32.
ICF, 2022b. Risk Screen on Substitutes in Chillers and Industrial
Process Air Conditioning (New Equipment); Substitute: HFO-123yf.
ICF, 2022c. Risk Screen on Substitutes in Chillers and Industrial
Process Air Conditioning (New Equipment); Substitute: R-452B.
ICF, 2022d. Risk Screen on Substitutes in Chillers and Industrial
Process Air Conditioning (New Equipment); Substitute: R-454A.
ICF, 2022e. Risk Screen on Substitutes in Chillers and Industrial
Process Air Conditioning (New Equipment); Substitute: R-454B.
ICF, 2022f. Risk Screen on Substitutes in Chillers and Industrial
Process Air Conditioning (New Equipment); Substitute: R-454C.
ICF, 2022g. Risk Screen on Substitutes in Residential Dehumidifiers
(New Equipment); Substitute: HFC-32.
ICF, 2022h. Risk Screen on Substitutes in Residential Dehumidifiers
(New Equipment); Substitute: R-452B.
ICF, 2022i. Risk Screen on Substitutes in Residential Dehumidifiers
(New Equipment); Substitute: R-454A.
ICF, 2022j. Risk Screen on Substitutes in Residential Dehumidifiers
(New Equipment); Substitute: R-454B.
ICF, 2022k. Risk Screen on Substitutes in Residential Dehumidifiers
(New Equipment); Substitute: R-454C.
ICF, 2022l. Risk Screen on Substitutes in Residential Dehumidifiers
(New Equipment); Substitute: HFO-1234yf.
ICF, 2022m. [Reserved--not referenced in this document.].
ICF, 2022n. Risk Screen on Substitutes in Residential and Light
Commercial Air Conditioning and Heat Pumps (New Equipment);
Substitute: HFC-32 (Difluoromethane).
ICF, 2022o. Risk Screen on Substitutes in Very Low Temperature
Refrigeration (New Equipment); Substitute: R-1150.
ICF, 2022p. Additional Assessment of the Potential Impact of
Hydrocarbon Refrigerants on Ground Level Ozone Concentrations. May
2020.
ICF, 2022q. Risk Screen on Substitutes in Total Flooding Systems in
Normally Unoccupied Spaces. Substitute: 2-bromo-3,3,3-
trifluoropropene (2-BTP).
ICF, 2022r. Risk Screen on Substitutes as Streaming Agents in Non-
Residential Applications. Substitute: 2-bromo-3,3,3-trifluoropropene
(2-BTP).
ICF, 2022s. Risk Screen on Substitutes in Total Flooding Systems in
Normally Unoccupied Spaces; Substitute: EXXFIRE [supreg].
ICF, 2022t. Risk Screen on Substitutes in Total Flooding Systems in
Normally Unoccupied Spaces; Substitute: Pyroquench-
[alpha]TM.
ICF, 2023a. Risk Screen on Substitutes in Residential and Light
Commercial Air Conditioning and Heat Pumps (New Equipment);
Substitute: HFC-32 (Difluoromethane).
ICF, 2023b. Risk Screen on Substitutes in Total Flooding Systems in
Normally Unoccupied Spaces; Substitute: Pyroquench-
[alpha]TM.
IPCC, 2007. Climate Change 2007: The Physical Science Basis.
Contribution of Working Group I to the Fourth Assessment Report of
the Intergovernmental Panel on Climate Change. Solomon, S., Qin, D.,
Manning, M., Chen, Z., Marquis, M., Averyt, K.B., Tignor, M., and
Miller, H.L. (eds.). Cambridge University Press. Cambridge, United
Kingdom and New York, NY, USA. Available online at: www.ipcc.ch/
publications_and_data/ar4/wg1/en/contents.html.
Kazil et al., 2014. J. Kazil, S. McKeen, S.-W. Kim, R. Ahmadov, G.A.
Grell, R.K. Talukdar, A.R. Ravishankara. ``Deposition and rainwater
concentrations of trifluoroacetic acid in the United States from the
use of HFO-1234yf,'' JGR Atmospheres. Volume 119, Issue 24. Pages
14,059-14,079. October 31, 2014. Available online at: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014JD022058.
Kim and Sunderland, 2018. Dennis Kim and Peter Sunderland,
``Viability of Various Ignition Sources to Ignite A2L Refrigerant
Leaks,'' 17th International Refrigeration and Air Conditioning
Conference at Purdue University, July, 2018. Available online at:
https://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=2885&context=iracc.
Myhre, et al., 2013. Myhre, G., D. Shindell, F.-M. Br[eacute]on, W.
Collins, J. Fuglestvedt, J. Huang, D. Koch, J.-F. Lamarque, D. Lee,
B. Mendoza, T. Nakajima, A. Robock, G. Stephens, T. Takemura and H.
Zhang, 2013: Anthropogenic and Natural Radiative Forcing. In:
Climate Change 2013: The Physical Science Basis. Contribution of
Working Group I to the Fifth Assessment Report of the
Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin,
G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y.
Xia, V. Bex and P.M. Midgley (eds.)]. Cambridge University Press,
Cambridge, United Kingdom and New York, NY, USA. Available online
at: https://www.ipcc.ch/report/ar5/wg1/.
National Fire Protection Agency (NFPA). 2018. NFPA 10: Standard for
Portable

Fire Extinguishers. Available online at: https://www.nfpa.org/.
National Fire Protection Agency (NFPA). 2018. NFPA 2001: Standard on
Clean Agent Fire Extinguishing Systems. Available online at: https://www.nfpa.org/.
National Fire Protection Agency (NFPA). 2018. NFPA 2010. Standard
for Fixed Aerosol Fire Extinguishing Systems. Available online at:
https://www.nfpa.org/.
Nielsen et al., 2007. Nielsen, O.J., Javadi, M.S., Sulbaek Andersen,
M.P., Hurley, M.D., Wallington, T.J., Singh, R. (2007). Atmospheric
chemistry of CF3CF=CH2: Kinetics and mechanisms of gas-phase
reactions with Cl atoms, OH radicals, and O3. Chemical Physics
Letters 439, 18-22. Available online at http://www.lexissecuritiesmosaic.com/gateway/FedReg/network_OJN_174_CF3CF=CH2.pdf.
Orkin, V.L. 2004. Photochemical Properties of 2-bromo-3,3,3-
trfluoropropene and semi-empirical kinetic estimates of its Global
Impacts on the Atmosphere. Prepared by the National Institute of
Standards and Technology Physical and Chemical Properties Division
for American Pacific Corporation. July 2004.
Patten, et al., 2011. Patten, K.O., V.G. Khamaganov, V.L. Orkin,
S.L. Baughcum, and D.J. Wuebbles (2011), OH reaction rate constant,
IR absorption spectrum, ozone depletion potentials and global
warming potentials of 2-bromo-3,3,3-trifluoropropene, J. Geophys.
Res., 116, D24307, doi:10.1029/2011JD016518.
Patten, et al., 2012. Patten, K.O., V.G. Khamaganov, V.L. Orkin,
S.L. Baughcum, and D.J. Wuebbles (2012), Correction to ``OH reaction
rate constant, IR absorption spectrum, ozone depletion potentials
and global warming potentials of 2-bromo-3,3,3-trifluoropropene,''
J. Geophys. Res., 117, D22301, doi:10.1029/2012JD019051.
UL 2129, 2017. UL Standard 2129--Halocarbon Clean Agent Fire
Extinguishers. Edition 3. January 5, 2017.
UL 60335-2-40, 2019. Household And Similar Electrical Appliances--
Safety--Part 2-40: Particular Requirements for Electrical Heat
Pumps, Air-Conditioners and Dehumidifiers. Third Edition. November
1, 2019.
UL Standard 61010-2-011, 2021. Safety Requirements for Electrical
Equipment for Measurement, Control, and Laboratory Use--Part 011:
Particular Requirements for Refrigerating Equipment. Second edition.
May 13, 2021.
Wickham, 2002. Status of Industry Efforts to Replace Halon Fire
Extinguishing Agents. March 2002. Available online at: https://www.epa.gov/snap/status-industry-efforts-replace-halon-fire-extinguishing-agents.
World Meteorological Organization (WMO), 2018. Burkholder et al.
Appendix A, Table A-1 in Scientific Assessment of Ozone Depletion:
2018, Global Ozone Research and Monitoring Project, Report No. 58,
WMO, Geneva, Switzerland, http://ozone.unep.org/science/assessment/sap.
World Meteorological Organization (WMO), 2022. Executive Summary.
Scientific Assessment of Ozone Depletion: 2022, GAW Report No. 278,
56 pp.; WMO: Geneva, 2022. Available online at https://ozone.unep.org/system/files/documents/Scientific-Assessment-of-Ozone-Depletion-2022-Executive-Summary.pdf
Zihan Zhai et al., 2015. Zihan Zhai, Jing Wu, Xia Hu, Li Li, Junyu
Guo, Boya Zhang, Jianxin Hu, and Jianbo Zhang. ``A 17-fold increase
of trifluoroacetic acid in landscape waters of Beijing, China during
the last decade,'' Chemosphere. 2015 Jun; 129:110-7. doi: 10.1016/
j.chemosphere.2014.09.033. Abstract available online at: https://pubmed.ncbi.nlm.nih.gov/25262947/

List of Subjects in 40 CFR Part 82

    Environmental protection, Administrative practice and procedure,
Air pollution control, Incorporation by reference, Stratospheric ozone
layer.

Michael S. Regan,
Administrator.

    For the reasons set forth in the preamble, EPA amends 40 CFR part
82 as follows:

PART 82--PROTECTION OF STRATOSPHERIC OZONE

0
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

0
2. Amend appendix R to subpart G of part 82 by:
0
a. Revising the heading;
0
b. Revising the table entitled ``Substitutes That Are Acceptable
Subject to Use Conditions'' and amending the ``Note'' immediately
following the table by removing the last two undesignated paragraphs.
    The revisions read as follows:

Appendix R to Subpart G of Part 82--Substitutes Subject to Use
Restrictions Listed in the December 20, 2011, Final Rule, Effective
February 21, 2012, and in the April 10, 2015 Final Rule, Effective May
11, 2015, and in the April 28, 2023 Final Rule, Effective May 30, 2023

                                                Substitutes That Are Acceptable Subject to Use Conditions
--------------------------------------------------------------------------------------------------------------------------------------------------------
              End-use                      Substitute               Decision                      Use conditions                  Further information
--------------------------------------------------------------------------------------------------------------------------------------------------------
1. Household refrigerators,          Isobutane (R-600a)      Acceptable subject to   As of September 7, 2018: These           Applicable OSHA
 freezers, and combination            Propane (R-290) R-      use conditions.         refrigerants may be used only in new     requirements at 29 CFR
 refrigerators and freezers (New      441A.                                           equipment designed specifically and      part 1910 must be
 equipment only).                                                                     clearly identified for the refrigerant   followed, including those
                                                                                (i.e., none of these substitutes may     at 29 CFR 1910.106
                                                                                be used as a conversion or               (flammable and
                                                                                ``retrofit'' refrigerant for existing    combustible liquids),
                                                                                equipment designed for a different       1910.110 (storage and
                                                                                refrigerant).                            handling of liquefied
                                                                                These refrigerants may be used only in    petroleum gases),
                                                                                a refrigerator or freezer, or            1910.157 (portable fire
                                                                                combination refrigerator and freezer,    extinguishers), and
                                                                                that meets all requirements listed in    1910.1000 (toxic and
                                                                                UL 60335-2-24.1 2 6                      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
                                                                                these refrigerants.
                                                                                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 these
                                                                                refrigerants.
                                                                                Any recovery equipment
                                                                                used should be designed
                                                                                for flammable
                                                                                refrigerants. Any
                                                                                refrigerant releases
                                                                                should be in a well-
                                                                                ventilated area, such as
                                                                                outside of a building.
                                                                                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.
2. Retail food refrigerators and     Isobutane (R-600a)      Acceptable subject to   As provided in clauses SB6.1.2 to        Room occupants should
 freezers (stand-alone units only)    Propane (R-290) R-      use conditions.         SB6.1.5 of UL 471,1 2 3 the following    evacuate the space
 (New equipment only).                441A.                                           markings must be attached at the         immediately following the
                                                                                locations provided and must be           accidental release of
                                                                                permanent:                               this refrigerant.
                                                                                (a) On or near any evaporators that can  If a service port is added
                                                                                be contacted by the consumer:            then retail food
                                                                                ``DANGER--Risk of Fire or Explosion.     refrigerators and
                                                                                Flammable Refrigerant Used. Do Not Use   freezers using these
                                                                                Mechanical Devices To Defrost            refrigerants should have
                                                                                Refrigerator. Do Not Puncture            service aperture fittings
                                                                                Refrigerant Tubing.''                    that differ from fittings
                                                                                (b) Near the machine compartment:         used in equipment or
                                                                                ``DANGER--Risk of Fire or Explosion.     containers using non-
                                                                                Flammable Refrigerant Used. To Be        flammable refrigerant.
                                                                                Repaired Only By Trained Service         ``Differ'' means that
                                                                                Personnel. Do Not Puncture Refrigerant   either the diameter
                                                                                Tubing.''                                differs by at least \1/
                                                                                (c) Near the machine compartment:         16\ inch or the thread
                                                                                ``CAUTION--Risk of Fire or Explosion.    direction is reversed
                                                                                Flammable Refrigerant Used. Consult      (i.e., right-handed vs.
                                                                                Repair Manual/Owner's Guide Before       left-handed). These
                                                                                Attempting To Service This Product.      different fittings should
                                                                                All Safety Precautions Must be           be permanently affixed to
                                                                                Followed.''                              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.
                                                                                (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 must be in
                                                                                letters no less than 6.4 mm (\1/4\
                                                                                inch) high.
                                                                                The refrigerator or freezer must have
                                                                                red, Pantone[supreg] 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.
3. Very low temperature              Ethane (R-170)........  Acceptable subject to   This refrigerant may be used only in     Applicable OSHA
 refrigeration Non-mechanical heat                            use conditions.         new equipment specifically designed      requirements at 29 CFR
 transfer (New equipment only).                                                       and clearly identified for the           part 1910 must be
                                                                                refrigerant (i.e., the substitute may    followed, including those
                                                                                not be used as a conversion or           at 29 CFR 1910.94
                                                                                ``retrofit'' refrigerant for existing    (ventilation) and
                                                                                equipment designed for other             1910.106 (flammable and
                                                                                refrigerants).                           combustible liquids),
                                                                                This refrigerant may only be used in      1910.110 (storage and
                                                                                equipment that meets all requirements    handling of liquefied
                                                                                in Supplement SB to UL 471.1 2 3 In      petroleum gases),
                                                                                cases where listing 3 of this table      1910.157 (portable fire
                                                                                includes requirements more stringent     extinguishers), and
                                                                                than those of UL 471, the appliance      1910.1000 (toxic and
                                                                                must meet the requirements of listing    hazardous substances).
                                                                                3 of this table in place of the         Proper ventilation should
                                                                                requirements in UL 471.                  be maintained at all
                                                                                The charge size for the equipment must    times during the
                                                                                not exceed 150 g (5.29 oz) in each       manufacture and storage
                                                                                circuit.                                 of equipment containing
                                                                                As provided in clauses SB6.1.2 to         hydrocarbon refrigerants
                                                                                SB6.1.5 of UL 471,1 2 3 the following    through adherence to good
                                                                                markings must be attached at the         manufacturing practices
                                                                                locations provided and must be           as per 29 CFR 1910.106.
                                                                                permanent:                               If refrigerant levels in
                                                                                (a) On or near any evaporators that can   the air surrounding the
                                                                                be contacted by the consumer:            equipment rise above one-
                                                                                ``DANGER--Risk of Fire or Explosion.     fourth of the lower
                                                                                Flammable Refrigerant Used. Do Not Use   flammability limit, the
                                                                                Mechanical Devices To Defrost            space should be evacuated
                                                                                Refrigerator. Do Not Puncture            and re-entry should occur
                                                                                Refrigerant Tubing.''                    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
                                                                                ethane. Special care
                                                                                should be taken to avoid
                                                                                contact with the skin
                                                                                since ethane, like many
                                                                                refrigerants, can cause
                                                                                freeze burns on the skin.
                                                                                A Class B dry powder type
                                                                                fire extinguisher should
                                                                                be kept nearby.

                                                                                (b) Near the machine compartment:     Technicians should only
                                                                                ``DANGER--Risk of Fire or             use spark-proof tools
                                                                                Explosion. Flammable Refrigerant      when working on equipment
                                                                                Used. To Be Repaired Only By          with flammable
                                                                                Trained Service Personnel. Do Not     refrigerants.
                                                                                Puncture Refrigerant Tubing.''       Any recovery equipment
                                                                                (c) Near the machine compartment:         used should be designed
                                                                                ``CAUTION--Risk of Fire or Explosion.    for flammable
                                                                                Flammable Refrigerant Used. Consult      refrigerants.
                                                                                Repair Manual/Owner's Guide Before      Any refrigerant releases
                                                                                Attempting To Service This Product.      should be in a well-
                                                                                All Safety Precautions Must be           ventilated area, such as
                                                                                Followed.''                              outside of a building.
                                                                                (d) On the exterior of the               Only technicians
                                                                                refrigerator: ``CAUTION--Risk of Fire    specifically trained in
                                                                                or Explosion. Dispose of Properly In     handling flammable
                                                                                Accordance With Federal Or Local         refrigerants should
                                                                                Regulations. Flammable Refrigerant       service equipment
                                                                                Used.''                                  containing ethane.
                                                                                (e) Near any and all exposed              Technicians should gain
                                                                                refrigerant tubing: ``CAUTION--Risk of   an understanding of
                                                                                Fire or Explosion Due To Puncture Of     minimizing the risk of
                                                                                Refrigerant Tubing; Follow Handling      fire and the steps to use
                                                                                Instructions Carefully. Flammable        flammable refrigerants
                                                                                Refrigerant Used.''                      safely.
                                                                                All of these markings must be in         Room occupants should
                                                                                letters no less than 6.4 mm (\1/4\       evacuate the space
                                                                                inch) high.                              immediately following the
                                                                                The refrigeration equipment must have     accidental release of
                                                                                red, Pantone[supreg] Matching System     this refrigerant.
                                                                                (PMS) #185 marked pipes, hoses, and     If a service port is added
                                                                                other devices through which the          then refrigeration
                                                                                refrigerant is serviced, typically       equipment using this
                                                                                known as the service port, to indicate   refrigerant should have
                                                                                the use of a flammable refrigerant.      service aperture fittings
                                                                                This color must be present at all        that differ from fittings
                                                                                service ports and where service          used in equipment or
                                                                                puncturing or otherwise creating an      containers using non-
                                                                                opening from the refrigerant circuit     flammable refrigerant.
                                                                                to the atmosphere might be expected      ``Differ'' means that
                                                                                (e.g., process tubes). The color mark    either the diameter
                                                                                must extend at least 2.5 centimeters     differs by at least \1/
                                                                                (1 inch) from the compressor and must    16\ inch or the thread
                                                                                be replaced if removed.                  direction is reversed
                                                                                (i.e., right-handed vs.
                                                                                left-handed). 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.
                                                                                Example of non-mechanical
                                                                                heat transfer using this
                                                                                refrigerant would be use
                                                                                in a secondary loop of a
                                                                                thermosiphon.
4. Vending Machines (New equipment   Isobutane (R-600a)      Acceptable subject to   These refrigerants may be used only in   Applicable OSHA
 only).                               Propane (R-290) R-      use conditions.         new equipment specifically designed      requirements at 29 CFR
                                      441A.                                           and clearly identified for the           part 1910 must be
                                                                                refrigerants (i.e., none of these        followed, including those
                                                                                substitutes may be used as a             at 29 CFR 1910.94
                                                                                conversion or ``retrofit'' refrigerant   (ventilation) and
                                                                                for existing equipment designed for      1910.106 (flammable and
                                                                                other refrigerants). Detaching and       combustible liquids),
                                                                                replacing the old refrigeration          1910.110 (storage and
                                                                                circuit from the outer casing of the     handling of liquefied
                                                                                equipment with a new one containing a    petroleum gases),
                                                                                new evaporator, condenser, and           1910.157 (portable fire
                                                                                refrigerant tubing within the old        extinguishers), and
                                                                                casing is considered ``new'' equipment   1910.1000 (toxic and
                                                                                and not a retrofit of the old,           hazardous substances).
                                                                                existing equipment.                     Proper ventilation should
                                                                                These substitutes may only be used in     be maintained at all
                                                                                equipment that meets all requirements    times during the
                                                                                in Supplement SA to UL 541.1 2 5 In      manufacture and storage
                                                                                cases where listing 4 of this table      of equipment containing
                                                                                includes requirements more stringent     hydrocarbon refrigerants
                                                                                than those of UL 541, the appliance      through adherence to good
                                                                                must meet the requirements of listing    manufacturing practices
                                                                                4 of this table in place of the          as per 29 CFR 1910.106.
                                                                                requirements in UL 541 The charge size   If refrigerant levels in
                                                                                for vending machines must not exceed     the air surrounding the
                                                                                150 g (5.29 oz) in each circuit.         equipment rise above one-
                                                                                As provided in clauses SA6.1.2 to         fourth of the lower
                                                                                SA6.1.5 of UL 541,1 2 5 the following    flammability limit, the
                                                                                markings must be attached at the         space should be evacuated
                                                                                locations provided and must be           and re-entry should occur
                                                                                permanent:                               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
                                                                                these refrigerants.
                                                                                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.
                                                                                (a) On or near any evaporators that   Technicians should only
                                                                                can be contacted by the consumer:     use spark-proof tools
                                                                                ``DANGER--Risk of Fire or             when working on
                                                                                Explosion. Flammable Refrigerant      refrigeration equipment
                                                                                Used. Do Not Use Mechanical Devices   with flammable
                                                                                To Defrost Refrigerator. Do Not       refrigerants.
                                                                                Puncture Refrigerant Tubing.''       Any recovery equipment
                                                                                (b) Near the machine compartment:         used should be designed
                                                                                ``DANGER--Risk of Fire or Explosion.     for flammable
                                                                                Flammable Refrigerant Used. To Be        refrigerants.
                                                                                Repaired Only By Trained Service        Any refrigerant releases
                                                                                Personnel. Do Not Puncture Refrigerant   should be in a well-
                                                                                Tubing.''                                ventilated area, such as
                                                                                (c) Near the machine compartment:         outside of a building.
                                                                                ``CAUTION--Risk of Fire or Explosion.   Only technicians
                                                                                Flammable Refrigerant Used. Consult      specifically trained in
                                                                                Repair Manual/Owner's Guide Before       handling flammable
                                                                                Attempting To Service This Product.      refrigerants should
                                                                                All Safety Precautions Must be           service refrigeration
                                                                                Followed.''                              equipment containing
                                                                                (d) On the exterior of the                these refrigerants.
                                                                                refrigerator: ``CAUTION--Risk of Fire    Technicians should gain
                                                                                or Explosion. Dispose of Properly In     an understanding of
                                                                                Accordance With Federal Or Local         minimizing the risk of
                                                                                Regulations. Flammable Refrigerant       fire and the steps to use
                                                                                Used.''                                  flammable refrigerants
                                                                                (e) Near any and all exposed              safely.
                                                                                refrigerant tubing: ``CAUTION--Risk of  Room occupants should
                                                                                Fire or Explosion Due To Puncture Of     evacuate the space
                                                                                Refrigerant Tubing; Follow Handling      immediately following the
                                                                                Instructions Carefully. Flammable        accidental release of
                                                                                Refrigerant Used.'' All of these         this refrigerant.
                                                                                markings must be in letters no less     If a service port is added
                                                                                than 6.4 mm (\1/4\ inch) high.           then refrigeration
                                                                                equipment using this
                                                                                refrigerant 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.
                                                                                left-handed). 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.

                                                                                The refrigeration equipment must have
                                                                                red, Pantone[supreg] 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.
5. Residential and light-commercial  Propane (R-290) R-441A  Acceptable subject to   These refrigerants may be used only in   Applicable OSHA
 air conditioning and heat pumps--                            use conditions.         new equipment specifically designed      requirements at 29 CFR
 self-contained room air                                                              and clearly identified for the           part 1910 must be
 conditioners only (New equipment                                                     refrigerants (i.e., none of these        followed, including those
 only).                                                                               substitutes may be used as a             at 29 CFR 1910.94
                                                                                conversion or ``retrofit'' refrigerant   (ventilation) and
                                                                                for existing equipment designed for      1910.106 (flammable and
                                                                                other refrigerants).                     combustible liquids),
                                                                                These refrigerants may only be used in    1910.110 (storage and
                                                                                equipment that meets all requirements    handling of liquefied
                                                                                in Supplement SA and Appendices B        petroleum gases),
                                                                                through F of UL 484.1 2 4 In cases       1910.157 (portable fire
                                                                                where listing 5 includes requirements    extinguishers), and
                                                                                more stringent than those of UL 484,     1910.1000 (toxic and
                                                                                the appliance must meet the              hazardous substances).
                                                                                requirements of listing 5 of this       Proper ventilation should
                                                                                table in place of the requirements in    be maintained at all
                                                                                UL 484.                                  times during the
                                                                                The charge size for the entire air        manufacture and storage
                                                                                conditioner must not exceed the          of equipment containing
                                                                                maximum refrigerant mass determined      hydrocarbon refrigerants
                                                                                according to Appendix F of UL 484 for    through adherence to good
                                                                                the room size where the air              manufacturing practices
                                                                                conditioner is used. The charge size     as per 29 CFR 1910.106.
                                                                                for these three refrigerants must in     If refrigerant levels in
                                                                                no case exceed 1,000 g (35.3 oz or       the air surrounding the
                                                                                2.21 lbs) of propane or 1,000 g (35.3    equipment rise above one-
                                                                                oz or 2.21 lb) of R-441A. For portable   fourth of the lower
                                                                                air conditioners, the charge size must   flammability limit, the
                                                                                in no case exceed 300 g (10.6 oz or      space should be evacuated
                                                                                0.66 lbs) of propane or 330 g (11.6 oz   and re-entry should occur
                                                                                or 0.72 lb) of R-441A. The               only after the space has
                                                                                manufacturer must design a charge size   been properly ventilated.
                                                                                for the entire air conditioner that     Technicians and equipment
                                                                                does not exceed the amount specified     manufacturers should wear
                                                                                for the unit's cooling capacity, as      appropriate personal
                                                                                specified in table A, B, C, D, or E of   protective equipment,
                                                                                this appendix R.                         including chemical
                                                                                goggles and protective
                                                                                gloves, when handling
                                                                                these refrigerants.
                                                                                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 air
                                                                                conditioning equipment
                                                                                with flammable
                                                                                refrigerants.
                                                                                As provided in clauses SA6.1.2 to        Any recovery equipment
                                                                                SA6.1.5 of UL 484,1 2 4 the following    used should be designed
                                                                                markings must be attached at the         for flammable
                                                                                locations provided and must be           refrigerants.
                                                                                permanent:                              Any refrigerant releases
                                                                                (a) On the outside of the air             should be in a well-
                                                                                conditioner: ``DANGER--Risk of Fire or   ventilated area, such as
                                                                                Explosion. Flammable Refrigerant Used.   outside of a building.
                                                                                To Be Repaired Only By Trained Service  Only technicians
                                                                                Personnel. Do Not Puncture Refrigerant   specifically trained in
                                                                                Tubing.''                                handling flammable
                                                                                (b) On the outside of the air             refrigerants should
                                                                                conditioner: ``CAUTION--Risk of Fire     service refrigeration
                                                                                or Explosion. Dispose of Properly In     equipment containing
                                                                                Accordance With Federal Or Local         these refrigerants.
                                                                                Regulations. Flammable Refrigerant       Technicians should gain
                                                                                Used.''                                  an understanding of
                                                                                (c) On the inside of the air              minimizing the risk of
                                                                                conditioner near the compressor:         fire and the steps to use
                                                                                ``CAUTION--Risk of Fire or Explosion.    flammable refrigerants
                                                                                Flammable Refrigerant Used. Consult      safely.
                                                                                Repair Manual/Owner's Guide Before      Room occupants should
                                                                                Attempting To Service This Product.      evacuate the space
                                                                                All Safety Precautions Must be           immediately following the
                                                                                Followed.''                              accidental release of
                                                                                (d) On the outside of each portable air   this refrigerant.
                                                                                conditioner: ``WARNING: Appliance       If a service port is added
                                                                                shall be installed, operated and         then air conditioning
                                                                                stored in a room with a floor area       equipment using this
                                                                                larger the ``X'' m\2\ (Y ft\2\).'' The   refrigerant should have
                                                                                value ``X'' on the label must be         service aperture fittings
                                                                                determined using the minimum room size   that differ from fittings
                                                                                in m\2\ calculated using Appendix F of   used in equipment or
                                                                                UL 484. For R-441A, use a lower          containers using non-
                                                                                flammability limit of 0.041 kg/m\3\ in   flammable refrigerant.
                                                                                calculations in Appendix F of UL 484.    ``Differ'' means that
                                                                                either the diameter
                                                                                differs by at least \1/
                                                                                16\ inch or the thread
                                                                                direction is reversed
                                                                                (i.e., right-handed vs.
                                                                                left-handed). 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.
                                                                                Air conditioning equipment
                                                                                in this category
                                                                                includes:
                                                                                Window air conditioning
                                                                                units.
                                                                                Portable room air
                                                                                conditioners.
                                                                                Packaged terminal air
                                                                                conditioners and heat
                                                                                pumps.
                                                                                All of these markings must be in
                                                                                letters no less than 6.4 mm (\1/4\
                                                                                inch) high.
                                                                                The air conditioning equipment must
                                                                                have red, Pantone[supreg] 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.

6. Residential and light-commercial  HFC-32................  Acceptable subject to   This refrigerant may be used only in     Applicable OSHA
 air conditioning and heat pumps--                            use conditions.         new equipment specifically designed      requirements at 29 CFR
 self-contained room air                                                              and clearly identified for the           part 1910 must be
 conditioners only (New equipment                                                     refrigerant (i.e., this substitute may   followed, including those
 only) manufactured from May 10,                                                      not be used as a conversion or           at 29 CFR 1910.94
 2015 and up to but not including                                                     ``retrofit'' refrigerant for existing    (ventilation) and
 May 30, 2023.                                                                        equipment designed for other             1910.106 (flammable and
                                                                                refrigerants).                           combustible liquids),
                                                                                This refrigerant may only be used in      1910.110 (storage and
                                                                                equipment that meets all requirements    handling of liquefied
                                                                                in Supplement SA and Appendices B        petroleum gases),
                                                                                through F of UL 484.1 2 4 In cases       1910.157 (portable fire
                                                                                where this listing 6 of this table       extinguishers), and
                                                                                includes requirements more stringent     1910.1000 (toxic and
                                                                                than those of UL 484, the appliance      hazardous substances).
                                                                                must meet the requirements of listing   Proper ventilation should
                                                                                6 of this table in place of the          be maintained at all
                                                                                requirements in UL 484.                  times during the
                                                                                The charge size for the entire air        manufacture and storage
                                                                                conditioner must not exceed the          of equipment containing
                                                                                maximum refrigerant mass determined      hydrocarbon refrigerants
                                                                                according to Appendix F of UL 484 for    through adherence to good
                                                                                the room size where the air              manufacturing practices
                                                                                conditioner is used. The manufacturer    as per 29 CFR 1910.106.
                                                                                must design a charge size for the        If refrigerant levels in
                                                                                entire air conditioner that does not     the air surrounding the
                                                                                exceed the amount specified for the      equipment rise above one-
                                                                                unit's cooling capacity, as specified    fourth of the lower
                                                                                in table A, B, C, D, or E of this        flammability limit, the
                                                                                appendix.                                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
                                                                                these refrigerants.
                                                                                Special care should be
                                                                                taken to avoid contact
                                                                                with the skin since these
                                                                                refrigerants, like many
                                                                                refrigerants, can cause
                                                                                freeze burns on the skin.
                                                                                For equipment following this listing 6,  A Class B dry powder type
                                                                                and as provided in clauses SA6.1.2 to    fire extinguisher should
                                                                                SA6.1.5 of UL 484,1 2 4 the following    be kept nearby.
                                                                                markings must be attached at the        Technicians should only
                                                                                locations provided and must be           use spark-proof tools
                                                                                permanent:                               when working on air
                                                                                (a) On the outside of the air             conditioning equipment
                                                                                conditioner: ``DANGER--Risk of Fire or   with flammable
                                                                                Explosion. Flammable Refrigerant Used.   refrigerants.
                                                                                To Be Repaired Only By Trained Service  Any recovery equipment
                                                                                Personnel. Do Not Puncture Refrigerant   used should be designed
                                                                                Tubing.''                                for flammable
                                                                                (b) On the outside of the air             refrigerants.
                                                                                conditioner: ``CAUTION--Risk of Fire    Any refrigerant releases
                                                                                or Explosion. Dispose of Properly In     should be in a well-
                                                                                Accordance With Federal Or Local         ventilated area, such as
                                                                                Regulations. Flammable Refrigerant       outside of a building.
                                                                                Used.''                                 Only technicians
                                                                                specifically trained in
                                                                                handling flammable
                                                                                refrigerants should
                                                                                service refrigeration
                                                                                equipment containing
                                                                                these refrigerants.
                                                                                Technicians should gain
                                                                                an understanding of
                                                                                minimizing the risk of
                                                                                fire and the steps to use
                                                                                flammable refrigerants
                                                                                safely.
                                                                                (c) On the inside of the air          Room occupants should
                                                                                conditioner near the compressor:      evacuate the space
                                                                                ``CAUTION--Risk of Fire or            immediately following the
                                                                                Explosion. Flammable Refrigerant      accidental release of
                                                                                Used. Consult Repair Manual/Owner's   this refrigerant.
                                                                                Guide Before Attempting To Service   If a service port is added
                                                                                This Product. All Safety              then air conditioning
                                                                                Precautions Must be Followed.''       equipment using this
                                                                                (d) On the outside of each portable air   refrigerant should have
                                                                                conditioner: ``WARNING: Appliance        service aperture fittings
                                                                                shall be installed, operated and         that differ from fittings
                                                                                stored in a room with a floor area       used in equipment or
                                                                                larger the ``X'' m\2\ (Y ft\2\).'' The   containers using non-
                                                                                value ``X'' on the label must be         flammable refrigerant.
                                                                                determined using the minimum room size   ``Differ'' means that
                                                                                in m\2\ calculated using Appendix F of   either the diameter
                                                                                UL 484.                                  differs by at least \1/
                                                                                All of these markings must be in          16\ inch or the thread
                                                                                letters no less than 6.4 mm (\1/4\       direction is reversed
                                                                                inch) high.                              (i.e., right-handed vs.
                                                                                The air conditioning equipment must       left-handed). These
                                                                                have red, Pantone[supreg] Matching       different fittings should
                                                                                System (PMS) #185 marked pipes, hoses,   be permanently affixed to
                                                                                and other devices through which the      the unit at the point of
                                                                                refrigerant is serviced, typically       service and maintained
                                                                                known as the service port, to indicate   until the end-of-life of
                                                                                the use of a flammable refrigerant.      the unit, and should not
                                                                                This color must be present at all        be accessed with an
                                                                                service ports and where service          adaptor.
                                                                                puncturing or otherwise creating an     Air conditioning equipment
                                                                                opening from the refrigerant circuit     in this category
                                                                                to the atmosphere might be expected      includes:
                                                                                (e.g., process tubes). The color mark   Window air conditioning
                                                                                must extend at least 2.5 centimeters     units.
                                                                                (1 inch) from the compressor and must   Portable room air
                                                                                be replaced if removed.                  conditioners.
                                                                                Packaged terminal air
                                                                                conditioners and heat
                                                                                pumps.
7. Residential and light-commercial  HFC-32................  Acceptable subject to   This refrigerant may only be used in
 air conditioning and heat pumps--                            use conditions.         equipment that meets all requirements
 self-contained room air                                                              in either:
 conditioners only (New equipment                                                    (1) Supplement SA and Appendices B
 only) manufactured from May 30,                                                      through F of UL 484 1 2 4 and listing
 2023 through January 1, 2024.                                                        6 of this table, or
                                                                                (2) UL 60335-2-40 1 2 7 and listing 8
                                                                                of this table.
8. Residential and light-commercial  HFC-32................  Acceptable Subject to   This refrigerant may be used only in     Applicable OSHA
 air conditioning and heat pumps--                            Use Conditions.         new equipment specifically designed      requirements at 29 CFR
 self-contained room air                                                              and clearly identified for the           part 1910 must be
 conditioners only (New equipment                                                     refrigerant (i.e., this substitute may   followed, including those
 only) manufactured on or after                                                       not be used as a conversion or           at 29 CFR 1910.94
 January 2, 2024.                                                                     ``retrofit'' refrigerant for existing    (ventilation) and
                                                                                equipment designed for other             1910.106 (flammable and
                                                                                refrigerants).                           combustible liquids),
                                                                                This substitute may only be used in air   1910.110 (storage and
                                                                                conditioning equipment that meets all    handling of liquefied
                                                                                requirements in UL 60335-2-40 1 2 7      petroleum gases), and
                                                                                and this listing 8 of this table.        1910.1000 (toxic and
                                                                                In cases where this listing 8 includes    hazardous substances).
                                                                                requirements more stringent than those  Proper ventilation should
                                                                                of UL 60335-2-40, the appliance must     be maintained at all
                                                                                meet the requirements of this listing    times during the
                                                                                8 in place of the requirements in UL     manufacture and storage
                                                                                60335-2-40.                              of equipment containing
                                                                                The following markings must be attached   flammable refrigerants
                                                                                at the locations provided and must be    through adherence to good
                                                                                permanent:                               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 reentry
                                                                                should occur only after
                                                                                the space has been
                                                                                properly ventilated.

                                                                                (a) On the outside of the equipment:  Technicians and equipment
                                                                                ``WARNING--Risk of Fire. Flammable    manufacturers should wear
                                                                                Refrigerant Used. To Be Repaired      appropriate personal
                                                                                Only By Trained Service Personnel.    protective equipment,
                                                                                Do Not Puncture Refrigerant           including chemical
                                                                                Tubing.''                             goggles and protective
                                                                                (b) On the outside of the equipment:      gloves, when handling
                                                                                ``WARNING--Risk of Fire. Dispose of      flammable refrigerants.
                                                                                Properly In Accordance With Federal Or   Special care should be
                                                                                Local Regulations. Flammable             taken to avoid contact
                                                                                Refrigerant Used.''                      with the skin which, like
                                                                                many refrigerants, can
                                                                                cause freeze burns on the
                                                                                skin.
                                                                                A class B dry powder type
                                                                                fire extinguisher should
                                                                                be kept nearby.
                                                                                (c) On the inside of the equipment    Technicians should only
                                                                                near the compressor: ``WARNING--      use spark-proof tools
                                                                                Risk of Fire. Flammable Refrigerant   when working on air
                                                                                Used. Consult Repair Manual/Owner's   conditioning equipment
                                                                                Guide Before Attempting to Service    with flammable
                                                                                This Product. All Safety              refrigerants.
                                                                                Precautions Must be Followed.''      Any recovery equipment
                                                                                (d) For any equipment pre-charged at      used should be designed
                                                                                the factory, on the equipment            for flammable
                                                                                packaging or on the outside of the       refrigerants. Only
                                                                                equipment: ``WARNING--Risk of Fire due   technicians specifically
                                                                                to Flammable Refrigerant Used. Follow    trained in handling
                                                                                Handling Instructions Carefully in       flammable refrigerants
                                                                                Compliance with National                 should service
                                                                                Regulations.''                           refrigeration equipment
                                                                                a. If the equipment is delivered          containing this
                                                                                packaged, this label shall be applied    refrigerant. Technicians
                                                                                on the packaging.                        should gain an
                                                                                b. If the equipment is not delivered      understanding of
                                                                                packaged, this label shall be applied    minimizing the risk of
                                                                                on the outside of the equipment near     fire and the steps to use
                                                                                the control panel or nameplate.          flammable refrigerants
                                                                                (e) On the equipment near the             safely.
                                                                                nameplate:                              Room occupants should
                                                                                a. At the top of the marking: ``Minimum   evacuate the space
                                                                                Installation height, X m (W ft).''       immediately following the
                                                                                This marking is only required if         accidental release of
                                                                                required by the UL 60335-2-40. The       this refrigerant.
                                                                                terms ``X'' and ``W'' shall be          Personnel commissioning,
                                                                                replaced by the numeric height as        maintaining, repairing,
                                                                                calculated per UL 60335-2-40. Note       decommissioning and
                                                                                that the formatting here is slightly     disposing of appliances
                                                                                different than UL 60335-2-40;            with this refrigerant
                                                                                specifically, the height in Inch-Pound   should obtain training
                                                                                units is placed in parentheses and the   and follow practices