Controls, Lennox International Inc., the Sporlan division of Parker
Hannifin Corporation (Sporlan), Rheem Manufacturing Company, and Trane
Technologies (Trane), seven equipment manufacturers; and two
environmental organizations, NRDC and EIA.
    We have grouped comments together and responded to the issues
raised by the comments in the sections that follow.

a. Substitutes and End-Use Proposed
    Comment: Several commenters voiced general support for the proposed
listing of HFC-32, R-452A, R-454A, R-454B, R-454C, and R-457A as
acceptable subject to use conditions in residential and light
commercial air conditioning and heat pumps. Chemours likewise supported
the proposal. Daikin voiced strong support and encouraged EPA to
approve HFC-32 quickly, noting that ``[o]ver 100 million R-32 split
system air conditioners have been sold since 2012'' and provided a list
showcasing their and other manufactures' implementation of air
conditioning products using A2L refrigerants in other countries. HARDI
supported these listings as ``one part of a larger process in the
industry's effort to phase down older refrigerants.''
    Response: EPA acknowledges these commenters' general support for
this proposed listing and appreciates the additional information
provided by Daikin on the use of HFC-32. We add to that information
that it has been reported that products using HFC-32 are operating in
over 90 countries.\34\ After considering all the public comments on
this proposal, we are finalizing this portion of the rule as proposed
with only a few modifications discussed elsewhere in this final rule.
---------------------------------------------------------------------------

    \34\ The Air Conditioning, Heating, and Refrigeration News, An
HVAC Technician's Guide to R-32, November 12, 2020. Available at
https://www.achrnews.com/articles/144053-an-hvac-technicians-guide-to-r-32?oly_enc_id=8731J4776701J6C.
---------------------------------------------------------------------------

b. Clarifications
    Comment: AHRI suggested that rather than ``mildly flammable
refrigerants'' EPA use the term ``refrigerants with lower
flammability'' to remain consistent with ASHRAE classifications.
    Response: EPA acknowledges this correction and has used the ``lower
flammability'' description for the A2L refrigerants in the preamble to
this final rule. In the ``Further information'' column of the
regulatory text in this final rule, we have used the term ``Flammable''
to replace the term ``Mildly flammable'' that was contained in the 2020
NPRM.
    Comment: AHRI pointed out that EPA indicated class 2L flammability
is determined based on testing at 73.4 [deg]F (23.0 [deg]C). They noted
that ASHRAE Standard 34-2019 requires testing at that temperature to
determine if flame propagation exists and if not, tests at 140 [deg]F
(60 [deg]C) are conducted to determine the refrigerant flammability
classification.
    Response: EPA acknowledges this clarification, which is
incorporated in the description of the ASHRAE standard testing
procedures to determine flammability classification in section II.B.3
above.
    Comment: AHRI provided additional detail on requirements contained
in UL 60335-2-40 and stated that some of the summary information EPA
provided (85 FR 35884-34885, June 12, 2020) may be taken out of context
or be incorrect. For instance, they stated alarms might not be required
for most systems and if refrigerant concentrations are found to exceed
certain thresholds a mitigation strategy such as ``fan operation and
air circulation or ventilation'' would be activated; shut-off valves
are only an option for VRF systems; connected space requirements exist
for duct-free equipment but are not required for ducted systems with
sensors/detectors; mitigation requirements for labeling, ignition
source controls, and other features are required for portable
appliances with charge sizes less than three times the LFL; that
similar requirements exist for fixed appliances where the charge is
less than six times the LFL; that detectors are required to be factory
installed, qualified and listed with the product for equipment above a
charge size calculated per the standard; outdoor air ventilation is
required ``[o]nly in a few cases;'' and while Annex HH is informative
as EPA stated in the proposal, installation and service instructions
are required by the UL standard and that these instructions would
tailor Annex HH recommendations to the specific product. Carrier
pointed out that Annex DD of the standard, while also informative,
provides guidance on what information should be included in operation,
service and installation manuals.
    Response: EPA acknowledges these clarifications and we agree with
the commenters' more detailed characterization of certain aspects of UL
Standard 60335-2-40. Our description in section II.B.5 above is offered
only for informational purposes and is not meant to be an exhaustive
summary of the standard. We emphasize that our use conditions are not
reliant on that informational description but rather adherence to the
actual requirements in the standard, which is incorporated by reference
in this rulemaking.
    Comment: AHRI stated that the proposed rule would require the use
of spark-free equipment but states such tools ``are not required for
A2L refrigerants as these refrigerants have a high minimum ignition
energy and sparks from tools and even some electrical devices is not a
competent ignition source for an A2L refrigerant due to their higher
minimum ignition energies.''
    Response: EPA noted in the proposal and reiterates in this final
rule that the information on spark-free tools is included in the
``Further information'' column of the regulatory text and so is not a
requirement of the rule. While we believe the use of spark-free tools
provides additional risk mitigation for technicians working with
flammable refrigerants, it was not proposed as a requirement and in
this final rule we maintain the recommendation in the ``Further
information'' column.
c. Use Conditions
i. Standards
    Comment: Daikin supported EPA's reliance on UL Standard 60335-2-40
as a basis for listing as acceptable with a use condition requiring
adherence to that standard. NRDC, speaking in part about the UL
Standard, stated that ``EPA's approach of reviewing, adjusting as
needed, and then adopting these standards' safe use requirements is
sound.''
    Response: EPA acknowledges Daikin's and NRDC's support for these
aspects of the proposed listing. After considering all the public
comments on this proposal, we are finalizing this listing, as described
in section II.B, including the use conditions related to UL 60335-2-40.
    Comment: Pointing to ASHRAE 15-2019 and the third edition of UL
60335-2-40, Chemours stated that the ``[a]pplication and product
standards for the end-uses referenced in the proposed rule are
complete.'' AHRI stated that industry has proposed requirements to
reduce risk with A2L refrigerants in UL Standard 60335-2-40, ASHRAE
Standard 15, and ASHRAE Standard 15.2. They provided some examples of
these including air circulation as well as control of ignition sources
and hot surface temperatures. Trane stated EPA's use conditions should
be linked to the current and future versions of ASHRAE 15 and ASHRAE
15.2, the latter of which they expected to be published in early 2021.
They noted that these standards govern the installation, operation and
maintenance of heating, ventilation, and air conditioning (HVAC)
systems using A2L refrigerants in commercial and residential
occupancies.
    Response: EPA understands that other risk mitigation requirements
have been proposed by the standards project committee for ASHRAE 15 and
ASHRAE 15.2 and may be used by the HVAC industry, just as mitigation
requirements have already been

included in the UL Standard that is adopted as a use condition in these
final SNAP listings. Nonetheless, we find that these A2L refrigerants
can be used safely provided the use conditions in this rule are
followed, including compliance with the requirements of the UL
Standard. In certain clauses, the UL Standard requires compliance with
ASHRAE 15. We also note that other authorities might impose additional
requirements, such as adoption of ASHRAE 15 and 15.2 in building codes,
that would provide an additional layer of safety above what EPA is
requiring. If in the future EPA were to determine that additional
requirements are needed after this rulemaking to ensure safe use of the
refrigerants in the residential and light commercial AC and heat pumps
end-use, EPA could consider any relevant changes and if any revisions
to this final rule should be proposed.
    Comment: The Alliance noted that the standard proposed to be
incorporated by reference, UL 60335-2-40, 3rd edition, will likely be
updated again. Daikin noted the standard is a ``continuous maintenance
standard'' supporting reference to the current edition. AHRI also
pointed out that ``new and updated standards will become more important
as standards sunset in the coming years.'' The Alliance expected the
fourth edition ``soon,'' and forecasted that most products manufactured
to this standard with the six A2L refrigerants would likely be
certified to that fourth edition. They asked that ``the UL 60355-2-40
[sic] standard update to include refrigerants that meet all the
requirements listed in the fourth edition as well.'' More generally
they asked that ``references to the standards be updated as new
editions become available for the products listed in SNAP Rule 23 and
other rules.'' Carrier also suggested EPA align with new safety
standards ``as new editions and future revisions become available'' and
Chemours offered similar suggestions. Sporlan and Trane suggested the
use condition reference the latest edition of the UL Standard, such
that the reference remains up to date. Sporlan suggested ``this use
condition be modified to reference the latest released edition of this
same standard, instead of tying Rule 23 exclusively to the 3rd
Edition.'' Trane noted that future editions of the UL Standard are
already underway and predicted the fourth edition would be complete
within two years (i.e., by July 27, 2022). Honeywell also supported
referencing a 4th edition and indicated that the process for writing
such would start in August 2020 and expected completion in 2021.
Honeywell asked EPA to wait until the 4th edition is published before
finalizing these listings of the A2L refrigerants and noted that the
3rd edition ``does not cover mitigation measures for external fires
caused by refrigerant leaks.'' AHRI also pointed out that there is an
ongoing effort to harmonize the relevant safety standards and
recommended that EPA update references to requirements for compliance
with product safety standards as new editions and revisions become
available. Referencing both the third and fourth edition of UL 60335-2-
40 as well as ASHRAE 15-2019 and the proposed ASHRAE 15.2, Johnson
Controls called for the acceptability listing of these A2L refrigerants
to be ``contingent upon the completion and harmonization of the
governing UL and ASHRAE standards for the safe design and application
of stationary air conditioning.'' Honeywell made a similar point,
referencing ASHRAE Standards 15 and 15.2, and suggested that these A2L
listings be delayed until this harmonization process was complete.
    Response: EPA acknowledges the information on further developments
in the UL 60335-2-40 standard and ASHRAE standards processes. After
considering all the public comments on this proposal, we are finalizing
this listing, as described in section II.B. EPA is incorporating by
reference the 3rd edition of the UL standard (the existing version of
the standard). As addressed below, we conclude, and several commenters
agree, that this version adequately addresses the use of these A2L
refrigerants in the equipment proposed.
    As we noted above, in certain cases the UL Standard refers to
ASHRAE 15-2019 for compliance. We are not, however, providing a use
condition based on one or more future editions of this standard, nor do
we feel it necessary or appropriate to rely on future standards and
harmonization efforts. Not only does EPA not know exactly what these
future standards may entail, those commenting on the proposed rule have
not had the opportunity to review those updates, as they have not yet
been finalized. Similarly, we do not find it necessary or appropriate
to wait for such actions to be finalized before taking this action. The
third edition of the UL Standard included extensive revisions
specifically to address flammability risks of A2L refrigerants and
reach industry-wide consensus. We further note that Chemours' comments
on the 2020 NPRM called finalization of this rule ``critical'' and
``timely'' and stated that with this final rule, the HVAC ``industry is
now well prepared to take this important step forward'' in the use of
lower-GWP--and lower overall risk to human health and the environment--
refrigerants in this end-use. If and when a 4th edition of the UL
Standard is released, EPA can consider any relevant changes and if any
revisions to this final rule should be proposed.
    Further, as mentioned by AHRI and Daikin, the UL standards are
under continuous maintenance--as are ASHRAE Standards 15 and 15.2--and
hence may change again even after the mentioned editions are published.
Nonetheless, most commenters supported moving forward with the rule
using the third edition of the UL Standard. Daikin, for instance,
``endorses EPA's determination that this consensus safety standard
adequately protects against the reasonably foreseeable risks associated
with the use of R-32 in the applications being considered.'' Chemours
added that ``[a]pplication and product standards for the end-uses
referenced in the proposed rule are complete'' and that ``these updated
standards sufficiently address the risks associated with the use of A2L
solutions.'' EPA concludes that reliance on the current UL Standard and
our other use conditions allows applicable products to be used safely.
    Regarding Honeywell's comment on external fires, we note that a
leak, even of a flammable refrigerant, does not ``cause'' a fire. It
would require an ignition source and a concentration of the refrigerant
higher than the lower flammability limit and below the higher
flammability limit. Requirements in the UL Standard mitigate the risk
of the equipment serving as an ignition source. As noted above, AHRI
pointed out that ``[f]or almost all applications air circulation will
be sufficient to dilute the refrigerant concentration in the event of a
catastrophic leak to below 25% of the LFL. Only in [a] rare case will
ventilation be used to introduce outside air.'' Further, the industry
is actively studying the behavior of A2L refrigerants (presuming a leak
does occur) in a structural fire. Should the results of this research
or other information lead in the future EPA to determine that
additional requirements are needed after this rulemaking to ensure safe
use of the refrigerants in the residential and light commercial AC and
heat pumps end-use, EPA could consider any relevant changes and if any
revisions to this final rule should be proposed.
    We understand that the Alliance is asking EPA to modify the use
condition so that it requires adherence to the fourth edition once the
fourth edition

publishes, similar to suggestions from other commenters, and to also
consider revising the listing beyond the six refrigerants in this
rulemaking to others. If in the future an updated standard is
published, or the harmonization with other standards is completed, EPA
could consider any relevant changes and if any revisions to this final
rule should be proposed. In a similar manner, and through the normal
SNAP submission review, we can consider taking future action to list,
or propose to list with use conditions, other refrigerants if we were
to determine we had enough information to do so.
    Comment: Honeywell predicted that ASHRAE Standard 15.2 would be
published in late 2021 or early 2022 and then adopted into model
building codes in 2024. They asked EPA to delay finalization of this
rule listing of A2L refrigerants until these actions occurred. They
stated that ``[c]urrent model mechanical and fire codes prohibit mildly
flammable refrigerants to be used in direct HVAC systems.''
    Response: EPA has not participated in the revisions to the model
codes discussed by Honeywell, and we find that these SNAP listings can
be finalized before Honeywell's prediction that a proposed standard
would be adopted into such codes, consistent with how we have proceeded
with other listings in past SNAP actions that could be affected by
anticipated revisions to building codes. As noted both in the proposal
and above in this final rule, however, information listed in the
``Further information'' column of the listings might refer to ``sound
operating practices that have already been identified in existing
industry and/or building codes or standards.'' (85 FR 35885, June 12,
2020). The listings in this final rule find certain refrigerants
acceptable and establishes EPA's use conditions, and do not require any
particular entity to use these refrigerants. Should other requirements
or standards also apply, such as building codes as Honeywell states,
other authorities would be responsible for ensuring such requirements
are addressed and enforced. We also note that some states are in the
process of updating their building code requirements to allow for
refrigerants with lower flammability (e.g., 2Ls), which will address
Honeywell's concern that such codes ``prohibit mildly flammable
refrigerants.'' Further, we are aware of the safe use of 2L
refrigerants in the end-uses covered by this rule in other countries.
While other states' building codes might currently prohibit use of
these refrigerants, the adoption by some states and the safe use
demonstrated gives support to listing these now. Further, we note that
regardless of the status of building codes, alternative means and
measures exist under which interested parties may present to the
Authority Having Jurisdiction (AHJ) evidence to demonstrate a similar
level of safety as provided under the existing building codes and
receive an exception to use an A2L refrigerant. For these reasons, the
Agency determines it is appropriate to finalize this final rule now. If
and when building codes are updated as indicated by the comment, EPA
can consider any relevant changes and if any revisions to this final
rule should be proposed.
    Comment: Rheem asked EPA to ``[p]rovide revised guidance for charge
limits for R-32 refrigerant, currently defined in SNAP Notice 25 and
based on unit capacity, to be governed by the safety standards.''
    Response: We believe Rheem is referring to SNAP Rule 19 (80 FR
19454, April 10, 2015) wherein EPA found HFC-32 acceptable, subject to
use conditions, for self-contained room air conditioners. One use
condition referenced parts of the August 3rd, 2012 version of UL
Standard 484, Edition 8 and another set charge size limits based on the
type of equipment (window unit, portable room AC, etc.) and cooling
capacity. In the proposal for this final rule we noted that we were not
proposing to revisit or modify the existing requirements from SNAP Rule
19, and consistent with that proposal, we are not finalizing changes to
these requirements. EPA understands that the standard we relied on in
Rule 19 might ``sunset'' in the future. Therefore, we will continue to
evaluate the market for the equipment addressed in that rule, including
HFC-32 in self-contained room air conditioners, and whether to
establish new or revised use conditions that reference UL 60335-2-40.
If in the future we wish to revise the existing requirements for HFC-32
self-contained room air conditioners, EPA could consider any relevant
changes and if any revisions to this final rule, or SNAP Rule 19,
should be proposed.
ii. New Equipment
    Comment: AHRI, Carrier, Daikin, EIA, Honeywell, Johnson Controls
and Lennox strongly support the proposed use condition that these A2L
refrigerants may only be used in new equipment and not retrofits. AHRI
noted that ``refrigerants from a higher ASHRAE flammability
classification'' should not be used to retrofit existing equipment;
i.e., these A2L lower flammability refrigerants should not be used to
retrofit systems using A1 (``no flame propagation'') refrigerants, such
as R-410A. Carrier added that such a use condition continues EPA's
precedent from similar listings of flammable refrigerants that were
only listed for new equipment.
    Response: EPA acknowledges these commenters' support of our
proposed use condition that finds these refrigerants acceptable for new
equipment and not for retrofits. After considering all the public
comments on this proposal, we are finalizing this listing, as described
in section II.B., including that use condition.
    Comment: AHRI, Carrier, Chemours, Daikin, Johnson Controls, and
Rheem sought clarification on footnote 33 in the proposed rule, which
sought to distinguish a ``new'' system from a ``retrofitted'' system.
AHRI noted that since the inception of the International Building Codes
in the 1990s, nail strips have been required to be used to support
existing piping within 1.5 inches of a wall when a new system is
installed. AHRI also indicated that any ``[e]xisting external piping
must be pressure-tested, leak-checked and vacuum-checked per the safety
standards during the installation process,'' a point also noted by
Johnson Controls. Daikin pointed to provisions in UL Standard 60335-2-
40 that address situations where ``partial units'' (as defined in the
Standard) are installed without new refrigerant tubing between indoor
and outdoor components. They also noted that clause DD.3.1DV.2 of the
UL Standard provides mandatory requirements, including strength test,
leak tightness checks, and compliance with national and local codes,
for field-installed refrigerant tubing and as such tubing meeting those
conditions may be reused. Carrier stated that ``[l]ine sets, however,
have been safely re-used in the HVACR field for decades'' and noted
that equipment manufacturer installation instructions and standards,
such as UL 60335-2-40 and ASHRAE 15, allow for reuse of line sets
provided they meet requirements including ``line sizing, as well as
pressure and vacuum testing of the line sets to ensure they are free of
leaks.'' Chemours offered similar observations. Rheem asked that
``external field-erected line sets'' be excluded from the definition of
a new unit, observing that replacement of these should be left to the
AHJ such as a building code inspector. Carrier and Chemours offered
alternative language for the footnote and suggested providing such
guidance in appendix W of the proposed regulatory text where the
listing is provided. On the other hand,

Honeywell states that the definition of ``new system'' should require
the installation of new refrigerant piping, tubing or linesets and
later stated that ``the tubing must be replaced, or at least inspected
and reinforced to meet proposed requirements under ASHRAE 15.2.'' They
said that existing tubing was not likely to meet minimum safety
regulations. Trane said ``[b]asing the proposed use conditions on
ASHRAE 15 and ASHRAE 15.2 incorporates appropriate piping guidance and
avoids the potential of unnecessary and costly restrictions.''
    Response: After consideration of these comments, EPA concludes that
the use of existing piping that is consistent with the use conditions
finalized--such as adherence to the UL 60335-2-40 Standard and the
inclusion of markings and labels as required--and the safety protocols
mentioned should not pose additional risk. We have clarified this in
section II.B.5.a and likewise in the text of the corresponding footnote
in section II.B.1.b of this final rule by not including ``refrigerant
tubing'' in the description of new equipment in this final action. As
such, existing piping does not need to be replaced for the equipment to
be considered ``new'' while a new compressor, evaporator, and condenser
are all required to be considered ``new.'' We believe this preamble
text sufficiently indicates our intention and so have not included
additional discussion in the regulatory text.
    As noted by other comments, discussed elsewhere in this final rule,
the UL Standard 60335-2-40, which is incorporated by reference through
this rule, addresses the situations where existing tubing might be used
when installing a new system using a refrigerant in this rule.
Consistent with the use conditions established in this rule, EPA finds
that this standard provides appropriate criteria by which an installer
would decide when exiting tubing may be used or needs to be replaced.
Accordingly, EPA concludes it is not necessary or appropriate to define
a ``new'' system to require installation of new refrigerant piping,
tubing or linesets. If the existing tubing and linesets do not meet
existing regulations separate from the UL Standard and our other use
conditions, e.g. applicable building codes, other regulations or other
authorities may require installation of new refrigerant piping, tubing
or linesets. EPA also does not find it appropriate to adopt ``proposed
requirements,'' including those proposed in October for ASHRAE 15.2, as
those have not been finalized and neither commenters nor EPA can know
the future content of a standard for certain until it is finalized.
    Comment: Carrier brought up the possibility that an outdoor
condensing unit using a non-flammable refrigerant (e.g., HCFC-22 or R-
410A) might illegally be replaced with one of the six refrigerants in
the listings in this final rule. Carrier urged EPA to work with the
industry concerning the replacement of all components, e.g. including
the indoor unit, as these instances will exhibit ``inspection and
enforcement challenges.''
    Response: EPA notes that the final listings of these six
refrigerants require they be used in a new system, including the
replacement of the indoor unit of an existing HCFC-22 or R-410A system
when the corresponding outdoor unit is replaced. We support education
and training across the industry to improve awareness of and compliance
with the requirements of this final rule. EPA intends to continue to
work with industry towards these goals.
    Comment: Carrier and Chemours sought clarification where EPA stated
in footnote 33 that the use condition for ``new equipment'' meant a
``completely new circuit.'' Chemours noted that a literal translation
of that might be to require that an entire system be replaced, even if
in the future a repair was being conducted on a system using one of the
six A2L refrigerants in this final rule.
    Response: EPA acknowledges Carrier's and Chemours' comments
pointing out this potential misinterpretation of the use condition.
Under the use conditions finalized in this rule, EPA intends that once
systems using these A2L refrigerants are installed, technicians, using
proper safety procedures, may service the equipment similarly to
servicing current day equipment using A1 refrigerants. This intention
to allow servicing and not strand equipment prematurely is consistent
with prior SNAP decisions, as well as with approaches that we have
taken under other provisions of Title VI of the CAA to achieve a smooth
phaseout and transition to safer alternatives. Such service would
include replacing components including the condensing unit, and other
adjustments. In those cases where one of the heat exchangers needs
replacing, EPA recommends that outdoor units and indoor units be
properly matched, including for instance replacing a functioning indoor
A2L evaporator unit if warranted when the original A2L outdoor unit is
replaced with a higher-efficiency outdoor unit using that same A2L
refrigerant.
iii. Labels
    Comment: AHRI, the Alliance, Carrier, Chemours, Daikin, Johnson
Controls, Lennox, and Rheem suggested that EPA rely on the labeling
requirements found in UL 60335-2-40, including the font size
requirement in the standard. Carrier held that the \1/8\-inch font size
specified in the standard is ``easily readable'' and further noted that
``visual icons and flammability symbols'' are required by the standard.
Lennox felt this size, which is half the size required in other EPA
listings (e.g., 80 FR 19454, April 10, 2015), was justified given the
refrigerants proposed have lower flammability (A2L) whereas the
referenced listings were for higher flammability refrigerants (A3).
Chemours stated that using a larger font ``disproportionally emphasizes
flammability versus other safety aspects including electrical or
pressure requirements.'' Rheem said that diverging from the UL Standard
``adds unnecessary complexity'' and Johnson Controls held that ``[t]he
introduction of new, unique requirements could lead to confusion in the
field and thus increase safety risks.'' EIA, on the other hand,
``strongly supports the labelling requirements . . . outlined on the
proposed rulemaking.''
    Response: As in other regulations promulgated under CAA section
612, EPA concludes that the proposed labeling requirement to use \1/4\-
inch fonts provides for an easier-to-read label than the \1/8\-inch
fonts in the standard; hence, the large font size provides an extra
layer of risk mitigation for technicians, consumers, retail store
owners, building owners and operators, first responders, and those
disposing of the equipment to readily understand the possibility that
the equipment contains a flammable refrigerant. Accordingly, EPA is
finalizing the larger text size as proposed.
    The only differences to the actual text of the label between UL
60335-2-40 and the requirement proposed and finalized in this rule are
to the label(s) on the indoor unit, where for instance the minimum
installation height in meters (m) and feet (ft) is to be referred to in
the format ``X m (Y ft)'' rather than ``X m and Y ft'' as in the UL
Standard, with X and Y calculated per the standard (85 FR 35881, June
12, 2020). EPA believes the format is appropriate and would help avoid
possible confusion if an installer were to interpret the label as
called for in the UL Standard to mean X meters plus Y feet (i.e., 4.28
times Y feet or 1.305 times X meters). Likewise, we proposed and are
finalizing the same change in text

format for the minimum room area label.
    Comment: AHRI and Daikin indicated EPA could in the future submit a
proposed change to UL to modify the labeling requirements. AHRI also
pointed out that there is an ongoing effort to harmonize the relevant
safety standards and recommended that EPA update references to
requirements for compliance with product safety standards as new
editions and revisions become available. They also suggested EPA
consider incorporating application standards such as ASHRAE 15 when
this harmonization process is complete.
    Response: As explained above, EPA finds that these A2L refrigerants
can be used safely provided the use conditions in this final rule are
followed, including compliance with the current (3rd edition) UL 60335-
2-40. Accordingly, EPA is taking final action on the proposal without
waiting for the harmonization process to be completed. EPA understands
that it could submit a change proposal to UL and if in the future EPA
were to determine that additional use conditions are needed after this
rulemaking to ensure safe use of the refrigerants in the residential
and light commercial AC and heat pumps end-use, EPA could consider any
relevant changes and if any revisions to this final rule should be
proposed, for instance by proposing to reference a revised standard and
specific application standards. Given the time required to propose,
discuss, and finalize any change to the UL Standard, EPA understands
that such a revised UL standard would not have been finalized for this
final rule, nor did we expect the harmonization effort to be complete.
If and when a 4th edition of the UL Standard is released, EPA can
consider any relevant changes and if any revisions to this final rule
should be proposed.
    Comment: Carrier stated that ``[t]he consensus safety standard CSA/
UL 60335-2-89 committee included representatives from fire service
which concluded that the proposed label requirements replicated from
UL/CSA 60335-2-40 in addition to label requirements for buildings in
building codes were sufficient from their perspective.'' Lennox made
the same point, saying the committee that developed the CSA/UL 60335-2-
89 standard ``included representatives from fire services which
concluded that the UL label requirements were sufficient.''
    Response: EPA appreciates learning that fire service personnel were
part of the consensus process for the 60335-2-89 standard but notes
that this is a different UL standard from the one addressed in this
rule. Thus, any conclusions about the adequacy of the label
requirements for that standard are not the same as a conclusion that
the label requirements for the UL standard addressed in this final rule
is sufficient, including the font size. For example, as the 60335-2-89
standard covers commercial refrigeration equipment, it is reasonable to
assume that the fire service personnel were only evaluating the label
requirements for the types of appliances covered by that standard, and
not necessarily agreeing to the adequacy of those requirements for the
equipment covered in this final rule, considering that much of the
equipment in the residential and light commercial AC and heat pumps
end-use has higher refrigerant charge sizes than the appliances covered
in the 60335-2-89 standard. As described elsewhere in this action, we
are concluding that the larger font size is appropriate under SNAP to
reduce risks to technicians, consumers, retail store owners, building
owners and operators, first responders, and those disposing the
appliance, consistent with EPA's approach in other prior SNAP rules.
    Comment: Daikin stated that the UL Standard was drafted under a
consensus process and requested that EPA's proposed use conditions
regarding labels be removed, allowing the standard to address any such
requirements.
    Response: EPA understands that this UL standard was drafted
following consensus practices, as were standards referenced in past EPA
listings of flammable refrigerants (e.g., 76 FR 78832, December 20,
2011; 80 FR 19454, April 10, 2015). In those cases, as in this action,
we find that the extra level of safety provided by EPA's labeling
requirement is appropriate under SNAP and that the larger font size
will reduce risks to technicians, consumers, retail store owners,
building owners and operators, first responders, and those disposing
the appliance. Accordingly, EPA is finalizing the use conditions
regarding labels as proposed.
iv. Red Markings
    Comment: Chemours indicates that using the same use condition for
red markings for these A2L refrigerants as was used for A3 refrigerants
previously listed acceptable amounts to a ``one size fits all''
approach. They disagreed that this should be done and specifically drew
attention to the UL 60335-2-40 standard, which provides different
requirements for equipment with A2L refrigerants compared to equipment
with A3 refrigerants. They indicated that ``treating A2 [sic] and A3
refrigerants the same is likely to cause confusion to end-users,
especially technicians responsible for installation and maintenance of
systems.'' Daikin, Lennox, and Rheem commented that the UL Standard was
adequate and as such the proposed requirement for red markings was not
warranted. EIA, on the other hand, ``strongly supports . . . the
required red markings on piping and hoses outlined on the proposed
rulemaking.''
    Response: EPA is finalizing the proposed requirement for red
markings. Consistent with other rules promulgated under CAA section
612, EPA's requirements of red markings add an extra layer of safety on
top of the labels required under the UL standards, and EPA concludes
this extra protection is appropriate for this listing under SNAP. As
noted above, these types of red markings would signal to the technician
that the refrigeration circuit that she/he was about to access
contained a flammable refrigerant, even if all warning labels were
somehow removed or were illegible or not understood (e.g., for non-
English speakers), and would provide similar notification to consumers,
retail store owners, building owners and operators, first responders,
and those disposing the appliance. We understand that UL 60335-2-40
treats A2L and A3 refrigerants differently; however, our proposal and
this final rule do not cover the A3 refrigerants. EPA relied on
different standards when we previously listed A3 refrigerants as
acceptable subject to use conditions and hence we are not treating
these two classes of refrigerants the same. For this SNAP listing, as
in our past listings for A3 (and also A2L) refrigerants, EPA concluded
that it is most important to warn technicians that there is a flammable
refrigerant present, not whether it is specifically an A2L, A2, or A3
refrigerant. Once warned, we would expect the technician then seek to
know which refrigerant is used and to proceed accordingly. While we see
that the flammability risk can be considered ``lower'' when using A2L
refrigerants compared to A3 refrigerants, a risk does exist and we find
that the red markings will provide an additional warning to
technicians, consumers, retail store owners, building owners and
operators, first responders, and those disposing the appliance. We also
note that the use of red markings is already required for HFC-32 as
well as A3 refrigerants in self-contained room air conditioners based
on previous regulations (80 FR 19454, April 10, 2015), and we are not
aware that the marking requirements have led to any confusion.

    Comment: AHRI read the proposal to be proposing all tubing be red,
but thought the intent was to only require such markings for service
ports.
    Response: EPA did not intend to propose that all tubing in
equipment using A2L refrigerants be red and we are not finalizing such
a requirement in this final rule. We are finalizing this use condition
as proposed and clarifying in section II.B.1.d that where the red
markings would be applied depends primarily on the equipment design.
The intent in the proposed rule and finalized in this rule is for the
red marking to be present at all service ports for equipment that
includes such service ports, and for the marking to extend one inch
from those ports. Likewise, if connections need to be made in the field
as opposed to at a factory, the one-inch red marking is required at
those connection points. If, however, equipment is provided without
such service ports, the one-inch red marking would be required at the
point in the equipment where any service involving the refrigerant,
including the evacuation of the refrigerant prior to equipment
disposal, would occur. On smaller appliances, we have noted in the past
that a process tube is often provided for such service, and that the
red marking would be required there. As we have also noted previously,
the manufacturer must decide the method of providing the red marking,
for instance via paint, plastic sleeve, shrink wrap, tape, etc.
    Comment: AHRI described the labeling requirements of the UL
standard for service ports and indicated that ``use of red markings and
the use of red hoses may cause some confusion.'' The reason the
commenter provided was that typical gage sets currently use red housing
for the higher-pressure side, a comment echoed by Carrier.
    Response: EPA does not agree that the similarity of color between
the gage set and the servicing port would lead to confusion. Given that
connections in the gage set also exist for the low-pressure side, we
feel that technicians would understand that a red marking of a service
port does not mean that only the red hose of a gage set must be
connected there. Other EPA requirements, such as the venting
prohibition under section 608(c) of the CAA and technician training
requirements, have existed since the early 1990s, and thus EPA believes
technicians will be able to use gage sets without confusion. Further,
training on flammable refrigerants which several commenters have
pointed to would reinforce the understanding of red service ports and
the use of gage sets. Finally, EPA notes that a similar red coloring
requirement use condition exists for flammable refrigerants, including
HFC-32, in other end-uses, and we are not aware that such coloring has
led to any confusion.
    Comment: Chemours stated that the requirement of red markings would
be difficult to implement in certain types of residential and light
commercial air conditioning equipment. As an example, they indicated
that quick-release Schrader valves ``may be impossible to get in red
color.''
    Response: EPA does not see evidence that the construction of red-
colored Schrader valves is impossible. In fact, Chemours' comments may
point to the reason why they say such valves are not available.
Chemours pointed out that the equipment types where flammable
refrigerants are currently acceptable subject to use conditions were
self-contained equipment generally using process tubes rather than
Schrader valves. Thus, there may have been no reason to develop them in
the past. However, that does not mean that such valves will not become
available if there is demand for such valves in the future. Although we
cannot confirm that such valves do not exist at all, it is important to
note that other means of applying the red marking may be used. The
regulatory text proposed and finalized in this rule states the red
``color must be applied at all service ports;'' hence, items such as a
red plastic sleeve or shrink wrap at both sides of the port, rather
than the entire port itself, would be acceptable means of meeting this
use condition.
d. SNAP Criteria
i. Flammability Risks and Safety
    Comment: AHRI and Lennox pointed to an approximately $7 million
research effort with the U.S. Department of Energy (DOE), the
California Air Resources Board (CARB) and other stakeholders on the
behavior and safe use of next generation refrigerants, including the
lower toxicity, lower flammability (A2L) refrigerants in the proposed
rule. Lennox emphasized that such research was used to develop the
safety standards and develop training. Sporlan said this research on 2L
refrigerants is ``of mature enough nature that they will be able to be
safely applied in new systems designed for 2L flammable refrigerants.''
AHRI detailed the extensive use of A2L refrigerants in the United
States and other countries and noted that ``it has yet to find
incidents related to A2L refrigerants.''
    Response: The Agency acknowledges AHRI's and Lennox's support for
this proposed listing. EPA acknowledges AHRI and Lennox for providing
this information and note Sporlan's comment, which supports EPA's
finding that the flammability risk of A2L refrigerants can be safely
addressed. After considering all the public comments on this proposal,
we are finalizing this listing, as described in section II.B.
    Comment: HARDI indicated that the industry is supporting updates to
the building, mechanical, and fire codes as well as transportation
regulations to allow new equipment to use new refrigerants, including
the A2L ones listed in the proposed rule. HARDI is working with the
industry ``to ensure a smooth and safe transition takes place.''
    Response: EPA acknowledges HARDI's information on their efforts to
support the safe use of these refrigerants in residential and light
commercial equipment as well as other types of equipment not covered by
this final rule.
    Comment: Honeywell commented that EPA should update the Risk
Screens for R-32 and R-454B included in supporting documents for the
proposed rule. They suggested that because ASHRAE Standard 15 mandates
use of a refrigerant concentration limit (RCL), and ASHRAE Standard 34
sets the RCL to be 25% of the LFL, EPA should use that amount rather
than the 100% of LFL.
    Response: EPA has consistently evaluated alternatives through a
risk screen process that begins with a highly conservative worst-case
scenario, such as where the entire refrigerant charge of a specific
equipment type leaks out rapidly in a specific room size. If a
substitute's concentrations remain below 100% of the LFL and relevant
toxicity limits in the worst-case scenario with highly conservative
assumptions, we do no further assessment. If the substitute's
concentrations exceed the LFL or a relevant toxicity limit in the
worst-case scenario, then we consider more typical scenarios based on
less conservative assumptions. EPA's risk screens indicate that none of
the types of equipment in this rule with these refrigerants came close
to 100% of the LFL, although they did exceed the 25% mark under the
most conservative scenarios analyzed.
    To the extent ASHRAE 15 is incorporated into building codes--as
Honeywell indicates--that requirement to adhere to the ASHRAE RCL would
provide an additional layer of safety above the use conditions set in
this final rule. More generally, the use of risk screens was developed
in the original SNAP Rule issued in 1994 and was not meant to
incorporate every possible risk factor. In fact, in that rule we stated

``[w]henever the initial risk screen indicated a potential risk, the
substitute was evaluated further to ascertain whether the potential
risk was accurately estimated and if management controls could reduce
any risk to acceptable levels.'' In this case, in the worst-case
scenario where the 25% RCL was exceeded, we concluded that the
additional risk mitigation offered by the UL Standard and our other use
conditions adequately addressed any such risk.
ii. Toxicity and PFAS
    Comment: EIA indicated there are ``concerns regarding potential
risks to human health and the environment due to toxicity of
trifluoroacetic acid (`TFA') and other by-products of breakdown of HFO-
1234yf, which is a component of the five refrigerant blends.'' They
pointed to scientific literature that finds HFO-1234yf has a 100%
conversion rate into TFA. They noted that increased use of alternative
refrigerants including HFOs has increased ecosystem levels of
anthropogenic TFA. EIA advised EPA to lead with caution but did not,
however, recommend that additional restrictions be placed on these
refrigerant blends based on TFA concerns. NRDC noted that ``EPA's risk
analyses do not evaluate the potential human health and environmental
impacts of approving additional uses for substances known to degrade
into [TFA].'' NRDC pointed to the previous analyses EPA performed on
TFA and requested that EPA revise those studies to include the
potential use of the five blends in the air-conditioning sector.
    Response: EPA does not agree that increased controls on HFOs or
other refrigerants is warranted to address generation of TFA. EPA
studied the potential generation of TFA when we first listed neat
(i.e., 100%, not in blends) HFO-1234yf as acceptable subject to use
conditions in motor vehicle air conditioners. The myriad studies we
referenced all concluded that the additional TFA from HFO-1234yf did
not pose a significant additional risk, even if it were assumed to be
used as the only refrigerant in all refrigeration and air conditioning
equipment (76 FR 17492-17493, March 29, 2011). More recently, the World
Meteorological Organization (WMO) concluded that ``[t]here is increased
confidence that [TFA] produced from degradation of HFCs, HCFCs, and
HFOs will not harm the environment over the next few decades'' while
also calling for periodic reevaluation of this conclusion.\35\ EPA
likewise finds that the data on TFA is not sufficient to propose or
establish additional restrictions under SNAP at this time. We further
note that the venting prohibition under section 608(c) of the CAA,
codified at 40 CFR 82.154(a), and accompanying refrigerant management
requirements reduce emissions of these refrigerants. EPA intends to
continue reviewing the research on potential impacts from TFA in the
future.
---------------------------------------------------------------------------

    \35\ World Meteorological Organization (WMO), Executive Summary:
Scientific Assessment of Ozone Depletion: 2018, World Meteorological
Organization, Global Ozone Research and Monitoring Project--Report
No. 58, 67 pp., Geneva, Switzerland, 2018. Available at https://ozone.unep.org/sites/default/files/2019-04/SAP-2018-Assessment-report-ES-rev%20%281%29.pdf.
---------------------------------------------------------------------------

    Comment: NRDC asked EPA to revise the Agency's analysis of the
substances included in this rulemaking that are polyfluoroalkyl or
perfluoroalkyl substances (PFAS), citing two recent papers on the
subject.\36\ \37\
---------------------------------------------------------------------------

    \36\ Cousins, Ian T, et al. The concept of essential use for
determining when uses of PFASs can be phased out. Environmental
Science: Processes & Impacts. The Royal Society of Chemistry. May
28, 2019. https://pubs.rsc.org/en/content/articlelanding/2019/em/c9em00163h#!divAbstract.
    \37\ Kwiatkowski, Carol F. et al. Scientific Basis for Managing
PFAS as a Chemical Class. Environmental Science & Technology
Letters. June 30, 2020. https://pubs.acs.org/doi/10.1021/acs.estlett.0c00255.
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    Response: EPA acknowledges these references. Upon review of these
papers, EPA does not conclude that any revisions to the evaluation of
overall risk to human health and the environment of the refrigerants
addressed in this final rule is necessary at this time. While the
papers NRDC referenced indicate there are potential health effects due
to accumulation of PFAS in the environment, they do not provide
information concerning the incremental effect that adoption of the five
refrigerants listed in this rule for the residential and light
commercial air conditioning end-use would have or how those effects
would compare to effects from other available substitutes in this end-
use.
    Both papers reference decision IV/25 by parties to the Montreal
Protocol on Substances that Deplete the Ozone Layer. That decision
concerns applying specific criteria and procedures in assessing an
essential use for the purposes of the control measures in Article 2 of
the Protocol and therefore is not directly relevant to the SNAP
program. Cousins et al. reviewed several examples of PFAS uses to
assess whether they would consider those uses to be ``essential,'' and
those uses did not include the refrigerants considered in this final
rule. Kwiatkowski et al. likewise did not provide an overview of
refrigerants to indicate any additional restrictions that they would
consider warranted.
    EPA intends to continue monitoring the scientific research on PFAS
in the future and consider whether this information is relevant for the
SNAP program.
e. Training
    Comment: ACCA argues that training and certification of technicians
on the handling of A2L refrigerants is necessary for safety and
consumer peace of mind. ACCA indicated it and others were developing
training and guidelines on A2L refrigerants and provided a list of
several aspects that they are addressing. Carrier noted that industry
has developed an exam for flammable refrigerants under the North
American Technician Excellence (NATE) certification organization.
Chemours also pointed to NATE and ACCA training as well as that by the
Refrigeration Service Engineers Society (RSES), AHRI, and that provided
by refrigerant producers and equipment manufacturers. Daikin also noted
that AHRI is developing guidelines for A2L refrigerants and that
equipment manufacturers are providing training to their service
personnel. Chemours stated that ``[t]echnician training, guidelines,
informational brochures, and certifications for flammable refrigerants
have been or are currently being developed by a number of industry
organizations'' and that ``recovery machines, leak detectors, service
cylinders and fittings are also available to the industry.'' HARDI
indicated the industry is supporting ``the development of training to
allow contractors to install newly designed equipment.'' ACCA asked EPA
to work with them and other industry stakeholders ``to develop and
implement training standards for the handling of flammable
refrigerants.'' Carrier similarly encouraged industry stakeholder
engagement and Chemours stated that given the number of programs that
already exist, EPA should collect a wide range of comments and move
forward with a separate rule on training that incorporates stakeholder
feedback. Rheem agreed that EPA should not undertake the creation of
new training requirements in this rule and went further to say they
were not in favor of a separate rulemaking, believing industry should
create any new training requirements.
    Response: EPA acknowledges the commenters' information related to
their work to educate and train technicians on the proper and safe use
of flammable refrigerants, including the A2L refrigerants in this final
rule. In the

proposed rule (85 FR 35886, June 12, 2020), EPA indicated it would take
advance comments on the possibility of proposing, in a separate rule,
training and service requirements, and we thank the industry for their
advance comments. We will take these comments into consideration to
determine whether we should propose such a rule on training or
undertake other future action. We note that certain safety requirements
for refrigerant recovery and/or recycling equipment are already
included in 40 CFR part 82, subpart F, under EPA's Refrigerant
Management Program. We also indicated in our proposal, as we did in
previous rules finding flammable refrigerants acceptable subject to use
conditions (e.g. 76 FR 78832, December 20, 2011; 80 FR 19454, April 10,
2015), that industry may be better suited than EPA to develop
appropriate training, and we see that this development has already
started across multiple fronts.
    Comment: AHRI ``strongly supports incorporation of new refrigerant
and requirements regarding A2L refrigerants into existing certification
requirements.'' The Alliance likewise supported this position asking
EPA to update the training and certification framework. Rheem
``encourages EPA to incorporate group A2L and group A3 refrigerants
into any requirements for training and certification that currently
exist for group A1 refrigerants.'' (emphasis in original). EIA
recommended that ``EPA mandate training and servicing requirements for
all flammable refrigerants'' holding that ``[i]n addition to putting
consumers at risk, not mandating such training would create confusion
for contractors if EPA has different rules and standards for different
refrigerants.''
    Response: Although AHRI and Rheem did not indicate which existing
training and certification requirements to which they were referring,
we believe it would include the existing technician certification
required under regulations implementing section 608 of the Clean Air
Act. EPA has incorporated information on flammable refrigerants into
the question bank for tests for such certification, which is required
to service equipment that contains the refrigerants covered by this
rulemaking, and has standards in place for refrigerant recovery and/or
recycling equipment used with such refrigerants. As we consider these
advance comments, we note that EPA's 608 test bank already includes
questions concerning A2L refrigerants and the appliances covered by
this rule, and EPA continues to review the test bank and can consider
adding additional questions in the future if appropriate. As noted
above, EPA will consider these advance comments as we determine what,
if any, additional actions we might take, including considering issuing
a proposed rulemaking addressing the possibility of mandating certain
additional training requirements.
    Comment: In their support of a separate rulemaking to update
training and certification requirements for A2L refrigerants, Carrier
suggested that a rulemaking provide ``training and service requirements
for anyone purchasing A2L refrigerants or servicing equipment
containing A2L refrigerants,'' noting that Australia and Japan have
credited such requirements in their successful adoption of such
refrigerants. Johnson Controls recommended a licensing system,
delivered by trade schools and accredited by established contractor
trade organizations, for handling A2L refrigerants. They emphasized the
need for hands-on training, including ``demonstration of skills as it
relates to the brazing, evacuating, charging, handling, storage,
transportation, etc. of mildly flammable, A2L refrigerants.''
    Response: EPA acknowledges the suggestion of undertaking a
rulemaking to provide training and service requirements for technicians
and the suggestion that it cover those purchasing A2L refrigerants and
servicing equipment containing them. Likewise, we acknowledge Johnson
Controls' recommendations of hands-on training and the topics suggested
to be included in a licensing training curriculum. As noted above, EPA
is taking these advance comments into consideration for possible future
industry engagement and possible rulemaking or other future action.
    Comment: EIA commented that industry has ``an aging and diminishing
workforce that need to be retrained.'' In addition to flammability,
they opined the training needs to cover other safety aspects including
health and environmental aspects of venting and accidental release.
They also stated that ``[t]here is significant confusion and lack of
clarity when it comes to applicability of the venting prohibition
itself, which still applies to the maintenance, service, repair, and
disposal of equipment containing HFCs.'' They noted that ``the
workforce needs to be provided basic awareness and education of
refrigerant lifecycle and impacts at different stages'' while also
noting that such education and training already exists. EIA offered
suggestions on how the training program they support could be managed,
such as allowing ``a certain grace period for servicing companies to
bring technicians into compliance before such training becomes
mandatory.'' They noted EPA could partner with the Department of Labor
to ``support the transition to low-GWP alternatives, particularly to
small businesses and women or minority owned companies,'' possibly
complementary to apprenticeship programs under the Workforce
Opportunity and Innovation Act.
    Response: EPA appreciates EIA's concern with respect to
technicians' handling of refrigerants. We further note that EPA's
current CAA section 608 technician certification test bank includes
questions concerning topics such as environmental impacts, laws and
regulations (including the venting prohibition and its applicability),
safety, flammable refrigerants, and safe disposal. Under the current
regulations, EPA can make changes to the test bank.
    EPA observes that while our proposed rulemaking took advance
comment on the possibility of proposing training and service
requirements for certain flammable refrigerants through a separate
rulemaking, we neither proposed to create a complementary technician
training and certification program in the current rulemaking, nor did
we propose to modify our existing CAA 608 technician certification
program in the current rulemaking. We appreciate EIA's suggestions and
as noted above we will take these comments into consideration in
determining whether to propose a rule or undertake other future action
on such training or service requirements.
    Comment: Honeywell stated that ``[a]ny transition to A2L
refrigerants should also be accompanied by a comprehensive training
program'' covering the installation and maintenance of equipment
containing A2L refrigerants. They held that such a training program
should be established, through rulemaking, by EPA before finalization
of this rule. Others, including manufacturers intending to use these
A2L refrigerants in their equipment, disagreed. For instance, Carrier
said they see no reason to delay this rulemaking in order to initiate a
separate rulemaking on training and certification for A2L refrigerants.
Daikin also supported EPA's approach of not proposing specific training
or service practices at this time, stating that manufacturers using A2L
refrigerants provide training to their service personnel.
    Response: After considering these comments, we agree with the
comments that it is not necessary to delay this rulemaking to undertake
separate action

on training, certification, or service practices for A2L refrigerants.
As noted by comments, training is already being provided by some
manufacturers and several organizations have developed or are in the
process of developing training. In past rulemakings listing flammable
refrigerants, we stated our conclusion that training is best left to
the industry, and we find no reason to change that conclusion in this
action. We are not aware of any safety issues that have arisen with the
equipment covered by those rules and our current understanding based on
comments to this rule is that action is already being taken to
adequately train service technicians. While we will nonetheless
consider these advance comments as we determine what, if any,
additional actions we might take, including considering issuing a
proposed rulemaking addressing the possibility of mandating certain
additional training requirements, our current understanding based on
comments to this rule is that the industry in general and interested
manufacturers in particular are already preparing for an adequate level
of training. As noted above, many additional sources are available, and
more are under development, to provide training on the A2L refrigerants
in this final rule and on flammable refrigerants in general.

C. Total Flooding: Removal of Powdered Aerosol E From the List of
Substitutes Acceptable Subject to Use Conditions

    Powdered Aerosol E, also marketed under the trade names of FirePro,
FirePro Xtinguish, and FireBan, is generated in an automated
manufacturing process during which the chemicals, in powder form, are
mixed and then supplied to end users as a solid contained within a fire
extinguisher. In the presence of heat, the solid converts to an aerosol
consisting mainly of potassium salts. EPA listed Powdered Aerosol E as
acceptable, subject to use conditions, as a total flooding agent (71 FR
56359, September 27, 2006). The use conditions required that Powdered
Aerosol E be used only in areas that are normally unoccupied, because
the Agency did not have sufficient information at that time supporting
its safe use in areas that are normally occupied. Based on a review of
additional information from the submitter to support the safe use of
Powdered Aerosol E in normally occupied spaces, EPA subsequently
determined that Powdered Aerosol E is also acceptable for use in total
flooding systems for normally occupied spaces (83 FR 50026, October 4,
2018). The listing provides that Powdered Aerosol E is acceptable for
total flooding uses, which includes both unoccupied and occupied
spaces. In the October 2018 listing action, EPA noted that in a
subsequent rulemaking, the Agency would remove the previous listing of
Powdered Aerosol E as acceptable, subject to use conditions since the
use condition is no longer applicable. We received no comments on the
proposal for this listing. Therefore, in this final rule, as proposed,
EPA is taking the ministerial action of removing that listing for
Powdered Aerosol E.

III. How is EPA responding to other public comments?

    EPA received other comments beyond the scope of this final action
and addresses them below.
    Comment: EIA stated ``that ODS are still undergoing replacement in
the residential and light commercial AC and heat pump end-use and are
subject to EPA's authority under the SNAP Program. EIA urges EPA to
promulgate additional SNAP Program regulations listing high-GWP
substitutes that pose a considerably higher comparable risk to the five
refrigerant blends, as unacceptable for this end-use, including R-410A,
R-404A, R-134a, and R-434A.''
    Response: This final rule lists additional substitutes as
acceptable, subject to use conditions, in the residential and light
commercial air conditioning end-use. The proposed rule did not discuss
finding other substitutes unacceptable in this end-use and such
listings are out of scope for this action. Accordingly, this comment
requires no further response.
    Comment: EIA noted EPA's ``Ongoing Responsibility to Protect Global
Ozone'' as it relates to methylene chloride
(CH2Cl2). The commenter stated that the
atmospheric concentrations of very short-lived substances (VSLS)
including methylene chloride are increasing and that they are
``increasingly seen as a threat to the progress made by the Montreal
Protocol . . . to protect the ozone layer.'' In order to address this
threat, EIA asks that the agency consider listing methylene chloride
and other similar VSLS as unacceptable in some end-uses.
    Response: We appreciate EIA's comments on VSLS and note that EPA
has taken domestic action on methylene chloride under the Toxic
Substances Control Act (TSCA) due to its toxicity (84 FR 11420, March
27, 2019). The proposed rule did not discuss listing VSLS as
unacceptable and such listings are out of scope for this final action.
Accordingly, this comment requires no further response.
    Comment: Trane commented that HFC-32, R-452B, and R-454B should
also be approved for scroll chillers. AHRI requested EPA to find HFC-32
and R-454B acceptable for positive displacement chillers, and Rheem
similarly asked that SNAP list group A2L refrigerants in such
equipment. Johnson Controls suggested listing HFC-32 and all five
blends acceptable for positive displacement chillers, to include
reciprocating, screw and scroll chillers. The Alliance, Carrier, and
Chemours agreed and encouraged listing HFC-32 and the five A2L blends
acceptable in chillers in general. Carrier pointed out that for
chillers, requirements for machine rooms would be needed and held that
the ASHRAE 15 standard could serve this purpose.
    Response: EPA notes that five of these six refrigerants (HFC-32, R-
452B, R-454A, R-454B, and R-454C) have been submitted to the SNAP
program for use in chillers and EPA is evaluating them for the chiller
end-use, encompassing both the centrifugal chiller and positive
displacement chiller end-uses. The other refrigerant, R-457A, has been
submitted but not for the chiller end-uses. The proposed rule addressed
listings for certain end-use categories, which did not include the
chiller end-use. The proposed rule did not discuss finding these
substitutes acceptable in other end uses, and such listings are out of
scope for this action. Accordingly, this comment requires no further
response.
    Comment: Rheem sought clarification as to which SNAP end-use Heat
Pump Pool Heaters (HPPH) and Heat Pump Water Heaters (HPWH) belong in
and for clarification as to whether an end use category currently
exists for these types of equipment.
    Response: The classification of HPPHs and HPWHs is beyond the scope
of this final rule. Accordingly, this comment requires no further
response. Nonetheless, EPA is now aware of this clarification request
and we invite Rheem and other manufacturers of such equipment to
further pursue this issue separately with EPA and the SNAP program.

IV. Statutory and Executive Order Reviews

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

    This action is not a significant regulatory action and was
therefore not submitted to the Office of Management and Budget (OMB)
for review.

B. Paperwork Reduction Act (PRA)

    This action does not impose any new information collection burden
under the PRA. OMB has previously approved the information collection
activities contained in the existing regulations and has assigned OMB
control number 2060-0226. The approved Information Collection Request
includes five types of respondent reporting and recordkeeping
activities pursuant to SNAP regulations: Submission of a SNAP petition,
filing a TSCA/SNAP Addendum, notification for test marketing activity,
recordkeeping for substitutes acceptable subject to use restrictions,
and recordkeeping for small volume uses. This rule contains no new
requirements for reporting or recordkeeping.

C. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic
impact on a substantial number of small entities under the RFA. In
making this determination, the impact of concern is any significant
adverse economic impact on small entities. An agency may certify that a
rule will not have a significant economic impact on a substantial
number of small entities if the rule relieves regulatory burden, has no
net burden or otherwise has a positive economic effect on the small
entities subject to the rule. This action allows the additional options
under SNAP of using R-32, R-448A, R-449A, R-449B, R-452B, R-454A, R-
454B, R-454C, and R-457A in the specified end-uses, but does not
mandate such use. Users who choose to avail themselves of this
flexibility for R-448A, R-449A, and R-449B must make a reasonable
effort to ascertain that other substitutes or alternatives are not
technically feasible and must document and keep records of the results
of such investigations. Because equipment for R-452B, R-454A, R-454B,
R-454C, and R-457A is not manufactured yet in the U.S. for the
residential and light commercial air conditioning and heat pumps end-
use, no change in business practice is required to meet the use
conditions, resulting in no adverse impact compared to the absence of
this rule. Equipment for R-32 already being manufactured has been
subject to similar use conditions, resulting in no adverse impact
compared to the absence of this rule. Thus, this final rule would not
impose new costs on small entities. We have therefore concluded that
this action will not impose a significant adverse regulatory burden for
all directly regulated small entities.

D. Unfunded Mandates Reform Act (UMRA)

    This action does not contain any unfunded mandate as described in
UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect
small governments. The action imposes no enforceable duty on any state,
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 fora.

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.
EPA has not conducted a separate analysis of risks to infants and
children associated with this rule. Any risks to children are not
different than the risks to the general population. 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 final 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

    This action involves technical standards. EPA uses and incorporates
by reference portions of the 2019 UL Standard 60335-2-40, which
establishes requirements for the evaluation of residential air
conditioning equipment and safe use of flammable refrigerants, among
other things. The standard is discussed in greater detail in section
II.B.5 of this preamble.
    The 2019 UL Standard 60335-2-40 is available at https://www.shopulstandards.com/ProductDetail.aspx?UniqueKey=36463, and may be
purchased by mail at: Comm 2000, 151 Eastern Avenue, Bensenville, IL
60106; Email<EMAIL_ADDRESS>Telephone: 1-888-853-3503 in
the U.S. or Canada (other countries dial 1-415-352-2178); internet
address: https://www.shopulstandards.com. The cost of the 2019 UL
Standard 60335-2-40 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 standard
incorporated by reference is reasonably available.

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

    EPA believes that it is not feasible to quantify any
disproportionately high and adverse human health or environmental
effects from this action on minority populations, low-income
populations and/or indigenous peoples, as specified in Executive Order
12898 (59 FR 7629, February 16, 1994) because for all affected
populations there is no requirement to use any of the alternatives
listed in this action.

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).

V. References

    Unless specified otherwise, all documents are available
electronically through the Federal Docket Management System, Docket
number EPA-HQ-OAR-2019-0698.

AHRI, 2017. Petition Requesting EPA SNAP Approval of R-448A/449A/
449B for Medium Temperature, Stand-Alone Retail Food Refrigeration
Equipment. Submitted March 20, 2017.
ASHRAE, 2019. ANSI/ASHRAE Standard 34-2019: Designation and Safety
Classification of Refrigerants.
Cousins, et al., 2019. Cousins, I.T., Goldenman G., Herzke, D.,
Lohmann, R., Miller, M., Ng, C.A., Patton, S., Scheringer, M.,
Trier, X., Vierke, L., Wang, Z., and DeWitt, J.C. (2019). The
concept of essential use for determining when uses of PFASs can be
phased out. Environ. Sci.: Processes Impacts, 2019, 21, 1803-1815.
Available online at: https://pubs.rsc.org/en/content/articlelanding/2019/em/c9em00163h#!divAbstract.
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, 2020a. Risk Screen on Substitutes in Retail Food Refrigeration
(Medium-temperature Stand-alone Units) (New Equipment); Substitute:
R-448A.
ICF, 2020b. Risk Screen on Substitutes in Retail Food Refrigeration
(Medium-temperature Stand-alone Units) (New Equipment); Substitute:
R-449A.
ICF, 2020c. Risk Screen on Substitutes in Retail Food Refrigeration
(Medium-temperature Stand-alone Units) (New Equipment); Substitute:
R-449B.
ICF, 2020d. Risk Screen on Substitutes in Residential and Light
Commercial Air-Conditioning and Heat Pumps (New Equipment);
Substitute: HFC-32.
ICF, 2020e. Risk Screen on Substitutes in Residential and Light
Commercial Air-Conditioning and Heat Pumps (New Equipment);
Substitute: R-452B.
ICF, 2020f. Risk Screen on Substitutes in Residential and Light
Commercial Air-Conditioning and Heat Pumps (New Equipment);
Substitute: R-454A.
ICF, 2020g. Risk Screen on Substitutes in Residential and Light
Commercial Air-Conditioning and Heat Pumps (New Equipment);
Substitute: R-454B.
ICF, 2020h. Risk Screen on Substitutes in Residential and Light
Commercial Air-Conditioning and Heat Pumps (New Equipment);
Substitute: R-454C.
ICF, 2020i. Risk Screen on Substitutes in Residential and Light
Commercial Air-Conditioning and Heat Pumps (New Equipment);
Substitute: R-457A.
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.
Javadi et al., 2008. Javadi, M.S., S[oslash]ndergaard, R., Nielsen,
O.J., Hurley, M.D., and Wellington, T.J., (2008). Atmospheric
chemistry of trans-CF3CH=CHF: products and mechanisms of hydroxyl
radical and chlorine atom-initiated oxidation. Atmospheric Chemistry
and Physics Discussions 8, 1069-1088. Available online at https://www.atmos-chem-phys.net/8/3141/2008/.
Kwiatkowski et al. 2020. Kwiatkowski, C.F., Andrews, D.Q., Birnbaum,
L.S., Bruton, T.A., DeWitt, J.C., Knappe, D.R.U., Maffini, M.V.,
Miller, M.F., Pelch, K.E., Reade, A., Soehl, A., Trier, X., Venier,
M., Wagner, C.C., Wang, Z., and Blum, A. (2020). Scientific Basis
for Managing PFAS as a Chemical Class. Environ. Sci. Technol. Lett.
2020, 7, 532-543. Available online at: https://pubs.acs.org/doi/10.1021/acs.estlett.0c00255.
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.
The Air Conditioning, Heating, and Refrigeration News, 2020. ``An
HVAC Technician's Guide to R-32,'' November 12, 2020. Available
online at: https://www.achrnews.com/articles/144053-an-hvac-technicians-guide-to-r-32?oly_enc_id=8731J4776701J6C
UL 60335-2-40, 2019. Standard for Safety for Household And Similar
Electrical Appliances--Safety--Part 2-40: Particular Requirements
for Electrical Heat Pumps, Air-Conditioners and Dehumidifiers. Third
Edition. November 1, 2019.

List of Subjects in 40 CFR Part 82

    Environmental protection, Administrative practice and procedure,
Air pollution control, Incorporation by reference, Reporting and
recordkeeping requirements, 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

Appendix O to Subpart G of Part 82 [Amended]

0
2. Appendix O to subpart G of part 82 is amended by removing the entry
``Total flooding; Powdered Aerosol E (FirePro[supreg])''.

0
3. Add appendix W to subpart G of part 82 to read as follows:

Appendix W to Subpart G of Part 82--Substitutes Listed in the May 6,
2021 Final Rule--Effective June 7, 2021

                                           Refrigerants--Substitutes Acceptable Subject to Narrowed Use Limits
--------------------------------------------------------------------------------------------------------------------------------------------------------
              End-use                      Substitute               Decision                   Narrowed use limits                Further information
--------------------------------------------------------------------------------------------------------------------------------------------------------
Retail food refrigeration-- medium-  R-448A, R-449A, R-449B  Acceptable Subject to   Acceptable only for use in new medium-   A possible reason for
 temperature stand-alone units (new                           Narrowed Use Limits.    temperature stand-alone units where      rejection of one or more
 only).                                                                               reasonable efforts have been made to     other alternative(s)
                                                                                ascertain that other alternatives are    could be based on ADA
                                                                                not technically feasible.                requirements.
                                                                                Users are required to document and
                                                                                retain the results of their technical
                                                                                investigation of alternatives for the
                                                                                purpose of demonstrating compliance.
                                                                                Information shall include descriptions
                                                                                of:
                                                                                Process or product in which
                                                                                the substitute is needed;
                                                                                Substitutes examined and
                                                                                rejected;
                                                                                Reason for rejection of
                                                                                other alternatives, e.g.,
                                                                                performance, technical or safety
                                                                                standards; and
                                                                                Anticipated date other
                                                                                substitutes will be available and
                                                                                projected time for switching.
--------------------------------------------------------------------------------------------------------------------------------------------------------

                                             Refrigerants--Substitutes Acceptable Subject to Use Conditions
--------------------------------------------------------------------------------------------------------------------------------------------------------
              End-use                      Substitute               Decision                      Use conditions                  Further information
--------------------------------------------------------------------------------------------------------------------------------------------------------
Residential and light commercial     R-452B, R-454A, R-      Acceptable Subject to   These refrigerants may be used only in   Applicable OSHA
 air conditioning and heat pumps      454B, R-454C and R-     Use Conditions.         new equipment specifically designed      requirements at 29 CFR
 (new only).                          457A.                                           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).                     combustible liquids),
                                                                                These substitutes may only be used in     1910.110 (storage and
                                                                                air conditioning equipment that meets    handling of liquefied
                                                                                all requirements in the 3rd edition of   petroleum gases), and
                                                                                UL 60335-2-40. 1 2 3 In cases where      1910.1000 (toxic and
                                                                                this appendix includes requirements      hazardous substances).
                                                                                more stringent than those of UL 60335-  Proper ventilation should
                                                                                2-40, the appliance must meet the        be maintained at all
                                                                                requirements of this appendix in place   times during the
                                                                                of the requirements in the UL            manufacture and storage
                                                                                Standard.                                of equipment containing
                                                                                The charge size for the equipment must    flammable refrigerants
                                                                                not exceed the maximum refrigerant       through adherence to good
                                                                                mass determined according to UL 60335-   manufacturing practices
                                                                                2-40 for the room size where the air     as per 29 CFR 1910.106.
                                                                                conditioner is used.                     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.
                                                                                The following markings must be attached  Technicians and equipment
                                                                                at the locations provided and must be    manufacturers should wear
                                                                                permanent:                               appropriate personal
                                                                                (a) On the outside of the air             protective equipment,
                                                                                conditioning equipment: ``WARNING--      including chemical
                                                                                Risk of Fire. Flammable Refrigerant      goggles and protective
                                                                                Used. To Be Repaired Only By Trained     gloves, when handling
                                                                                Service Personnel. Do Not Puncture       flammable refrigerants.
                                                                                Refrigerant Tubing.''                    Special care should be
                                                                                (b) On the outside of the air             taken to avoid contact
                                                                                conditioning equipment: ``WARNING--      with the skin which, like
                                                                                Risk of Fire. Dispose of Properly In     many refrigerants, can
                                                                                Accordance With Federal Or Local         cause freeze burns on the
                                                                                Regulations. Flammable Refrigerant       skin.
                                                                                Used.''                                 A class B dry powder type
                                                                                (c) On the inside of the air              fire extinguisher should
                                                                                conditioning equipment near the          be kept nearby.
                                                                                compressor: ``WARNING--Risk of Fire.    Technicians should only
                                                                                Flammable Refrigerant Used. Consult      use spark-proof tools
                                                                                Repair Manual/Owner's Guide Before       when working on air
                                                                                Attempting To Service This Product.      conditioning equipment
                                                                                All Safety Precautions Must be           with flammable
                                                                                Followed.''                              refrigerants.
                                                                                (d) For any equipment pre-charged at     Any recovery equipment
                                                                                the factory, on the equipment            used should be designed
                                                                                packaging: ``WARNING--Risk of Fire due   for flammable
                                                                                to Flammable Refrigerant Used. Follow    refrigerants. Only
                                                                                Handling Instructions Carefully in       technicians specifically
                                                                                Compliance with National                 trained in handling
                                                                                Regulations.''                           flammable refrigerants
                                                                                (e) On the indoor unit near the           should service
                                                                                nameplate:                               refrigeration equipment
                                                                                a. At the top of the marking: ``Minimum   containing these
                                                                                Installation height, X m (W ft)''.       refrigerants. Technicians
                                                                                This marking is only required if         should gain an
                                                                                required by UL 60335-2-40. The terms     understanding of
                                                                                ``X'' and ``W'' shall be replaced by     minimizing the risk of
                                                                                the numeric height as calculated per     fire and the steps to use
                                                                                the UL Standard. Note that the           flammable refrigerants
                                                                                formatting here is slightly different    safely.
                                                                                than the UL Standard; specifically,     Room occupants should
                                                                                the height in Inch-Pound units is        evacuate the space
                                                                                placed in parentheses and the word       immediately following the
                                                                                ``and'' has been replaced by the         accidental release of
                                                                                opening parenthesis.                     this refrigerant.
                                                                                b. Immediately below (a) above or at     Personnel commissioning,
                                                                                the top of the marking if (a) is not     maintaining, repairing,
                                                                                required: ``Minimum room area            decommissioning and
                                                                                (operating or storage), Y m\2\ (Z        disposing of appliances
                                                                                ft\2\)''. The terms ``Y'' and ``Z''      with these refrigerants
                                                                                shall be replaced by the numeric area    should obtain training
                                                                                as calculated per the UL Standard.       and follow practices
                                                                                Note that the formatting here is         consistent with Annex HH
                                                                                slightly different than the UL           of UL 60335-2-40, 3rd
                                                                                Standard; specifically, the area in      edition.1 2 3
                                                                                Inch-Pound units is placed in           CAA section 608(c)(2)
                                                                                parentheses and the word ``and'' has     prohibits knowingly
                                                                                been replaced by the opening             venting or otherwise
                                                                                parenthesis.                             knowingly releasing or
                                                                                disposing of substitute
                                                                                refrigerants in the
                                                                                course of maintaining,
                                                                                servicing, repairing or
                                                                                disposing of an appliance
                                                                                or industrial process
                                                                                refrigeration.
                                                                                Department of
                                                                                Transportation
                                                                                requirements for
                                                                                transport of flammable
                                                                                gases must be followed.
                                                                                Flammable refrigerants
                                                                                being recovered or
                                                                                otherwise disposed of
                                                                                from residential and
                                                                                light commercial air
                                                                                conditioning appliances
                                                                                are likely to be
                                                                                hazardous waste under the
                                                                                Resource Conservation and
                                                                                Recovery Act (RCRA) (see
                                                                                40 CFR parts 260-270).

                                                                                (f) For non-fixed equipment,
                                                                                including portable air
                                                                                conditioners, window air
                                                                                conditioners, packaged terminal air
                                                                                conditioners and packaged terminal
                                                                                heat pumps, on the outside of the
                                                                                product: ``WARNING--Risk of Fire or
                                                                                Explosion--Store in a well
                                                                                ventilated room without
                                                                                continuously operating flames or
                                                                                other potential ignition.''
                                                                                (g) For fixed equipment, including
                                                                                rooftop units and split air
                                                                                conditioners, ``WARNING--Risk of
                                                                                Fire--Auxiliary devices which may
                                                                                be ignition sources shall not be
                                                                                installed in the ductwork, other
                                                                                than auxiliary devices listed for
                                                                                use with the specific appliance.
                                                                                See instructions.''
                                                                                (h) All of these markings must be in
                                                                                letters no less than 6.4 mm (\1/4\
                                                                                inch) high.
                                                                                The equipment must have red Pantone
                                                                                Matching System (PMS) #185 or RAL 3020
                                                                                marked service ports, pipes, hoses, or
                                                                                other devices through which the
                                                                                refrigerant passes, to indicate the
                                                                                use of a flammable refrigerant. This
                                                                                color must be applied at all service
                                                                                ports and other parts of the system
                                                                                where service puncturing or other
                                                                                actions creating an opening from the
                                                                                refrigerant circuit to the atmosphere
                                                                                might be expected and must extend a
                                                                                minimum of one (1) inch (25mm) in both
                                                                                directions from such locations and
                                                                                shall be replaced if removed.
Residential and light commercial     R-32..................  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
 (new only), excluding self-                                                          and clearly identified for the           part 1910 must be
 contained room air conditioners.                                                     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).                     combustible liquids),
                                                                                These substitutes may only be used in     1910.110 (storage and
                                                                                air conditioning equipment that meets    handling of liquefied
                                                                                all requirements in the 3rd edition of   petroleum gases), and
                                                                                UL 60335-2-40.1 2 3 In cases where       1910.1000 (toxic and
                                                                                this appendix includes requirements      hazardous substances).
                                                                                more stringent than those of UL 60335-  Proper ventilation should
                                                                                2-40, the appliance must meet the        be maintained at all
                                                                                requirements of this appendix in place   times during the
                                                                                of the requirements in the UL            manufacture and storage
                                                                                Standard.                                of equipment containing
                                                                                The charge size for the equipment must    flammable refrigerants
                                                                                not exceed the maximum refrigerant       through adherence to good
                                                                                mass determined according to UL 60335-   manufacturing practices
                                                                                2-40 for the room size where the air     as per 29 CFR 1910.106.
                                                                                conditioner is used.                     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.
                                                                                The following markings must be attached  Technicians and equipment
                                                                                at the locations provided and must be    manufacturers should wear
                                                                                permanent:                               appropriate personal
                                                                                (a) On the outside of the air             protective equipment,
                                                                                conditioning equipment: ``WARNING--      including chemical
                                                                                Risk of Fire. Flammable Refrigerant      goggles and protective
                                                                                Used. To Be Repaired Only By Trained     gloves, when handling
                                                                                Service Personnel. Do Not Puncture       flammable refrigerants.
                                                                                Refrigerant Tubing.''                    Special care should be
                                                                                (b) On the outside of the air             taken to avoid contact
                                                                                conditioning equipment: ``WARNING--      with the skin which, like
                                                                                Risk of Fire. Dispose of Properly In     many refrigerants, can
                                                                                Accordance With Federal Or Local         cause freeze burns on the
                                                                                Regulations. Flammable Refrigerant       skin.
                                                                                Used.''                                 A class B dry powder type
                                                                                (c) On the inside of the air              fire extinguisher should
                                                                                conditioning equipment near the          be kept nearby.
                                                                                compressor: ``WARNING--Risk of Fire.    Technicians should only
                                                                                Flammable Refrigerant Used. Consult      use spark-proof tools
                                                                                Repair Manual/Owner's Guide Before       when working on air
                                                                                Attempting To Service This Product.      conditioning equipment
                                                                                All Safety Precautions Must be           with flammable
                                                                                Followed.''                              refrigerants.
                                                                                (d) For any equipment pre-charged at     Any recovery equipment
                                                                                the factory, on the equipment            used should be designed
                                                                                packaging: ``WARNING--Risk of Fire due   for flammable
                                                                                to Flammable Refrigerant Used. Follow    refrigerants. Only
                                                                                Handling Instructions Carefully in       technicians specifically
                                                                                Compliance with National Regulations''   trained in handling
                                                                                (e) On the indoor unit near the           flammable refrigerants
                                                                                nameplate:                               should service
                                                                                a. At the top of the marking: ``Minimum   refrigeration equipment
                                                                                Installation height, X m (W ft)''.       containing this
                                                                                This marking is only required if         refrigerant. Technicians
                                                                                required by UL 60335-2-40. The terms     should gain an
                                                                                ``X'' and ``W'' shall be replaced by     understanding of
                                                                                the numeric height as calculated per     minimizing the risk of
                                                                                the UL Standard. Note that the           fire and the steps to use
                                                                                formatting here is slightly different    flammable refrigerants
                                                                                than the UL Standard; specifically,      safely.
                                                                                the height in Inch-Pound units is       Room occupants should
                                                                                placed in parentheses and the word       evacuate the space
                                                                                ``and'' has been replaced by the         immediately following the
                                                                                opening parenthesis.                     accidental release of
                                                                                b. Immediately below (a) above or at      this refrigerant.
                                                                                the top of the marking if (a) is not    Personnel commissioning,
                                                                                required: ``Minimum room area            maintaining, repairing,
                                                                                (operating or storage), Y m\2\ (Z        decommissioning and
                                                                                ft\2\)''. The terms ``Y'' and ``Z''      disposing of appliances
                                                                                shall be replaced by the numeric area    with this refrigerant
                                                                                as calculated per the UL Standard.       should obtain training
                                                                                Note that the formatting here is         and follow practices
                                                                                slightly different than the UL           consistent with Annex HH
                                                                                Standard; specifically, the area in      of UL 60335-2-40, 3rd
                                                                                Inch-Pound units is placed in            edition.\1\ \2\ \3\
                                                                                parentheses and the word ``and'' has    CAA section 608(c)(2)
                                                                                been replaced by the opening             prohibits knowingly
                                                                                parenthesis.                             venting or otherwise
                                                                                knowingly releasing or
                                                                                disposing of substitute
                                                                                refrigerants in the
                                                                                course of maintaining,
                                                                                servicing, repairing or
                                                                                disposing of an appliance
                                                                                or industrial process
                                                                                refrigeration.
                                                                                Department of
                                                                                Transportation
                                                                                requirements for
                                                                                transport of flammable
                                                                                gases must be followed.
                                                                                Flammable refrigerants
                                                                                being recovered or
                                                                                otherwise disposed of
                                                                                from residential and
                                                                                light commercial air
                                                                                conditioning appliances
                                                                                are likely to be
                                                                                hazardous waste under the
                                                                                Resource Conservation and
                                                                                Recovery Act (RCRA) (see
                                                                                40 CFR parts 260-270).
                                                                                (f) For fixed equipment, including
                                                                                rooftop units and split air
                                                                                conditioners, ``WARNING--Risk of
                                                                                Fire--Auxiliary devices which may
                                                                                be ignition sources shall not be
                                                                                installed in the ductwork, other
                                                                                than auxiliary devices listed for
                                                                                use with the specific appliance.
                                                                                See instructions.''
                                                                                (g) All of these markings must be in
                                                                                letters no less than 6.4 mm (\1/4\
                                                                                inch) high.

                                                                                The equipment must have red Pantone
                                                                                Matching System (PMS) #185 or RAL
                                                                                3020 marked service ports, pipes,
                                                                                hoses, or other devices through
                                                                                which the refrigerant passes, to
                                                                                indicate the use of a flammable
                                                                                refrigerant. This color must be
                                                                                applied at all service ports and
                                                                                other parts of the system where
                                                                                service puncturing or other actions
                                                                                creating an opening from the
                                                                                refrigerant circuit to the
                                                                                atmosphere might be expected and
                                                                                must extend a minimum of one (1)
                                                                                inch (25mm) in both directions from
                                                                                such locations and shall be
                                                                                replaced if removed.
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\1\ UL 60335-2-40, Standard for Safety for Household And Similar Electrical Appliances--Safety--Part 2-40: Particular Requirements for Electrical Heat
  Pumps, Air-Conditioners and Dehumidifiers, Third edition, Dated November 1, 2019.