refrigerants. These increased costs however are often offset by the
high energy efficiencies typically achieved with R-717 systems. We also
pointed to equipment designs, such as low charge packaged R-717
systems, R-717/R-744 cascade systems, and indirect secondary-loop
systems using R-717 as the primary refrigerant in a machine room
separated from the cooled interior, that can overcome some limitations
on the use of R-717. These systems are described in market
characterizations found in the docket to this rule (EPA-HQ-OAR-2015-
0663).\130\ While R-717 is the most common refrigerant used in cold
storage warehouses, others have used CFC-12, R-502 and HCFC-22 and more
recently R-404A, R-407C, R-407F, R-410A, or R-507A.
---------------------------------------------------------------------------

    \129\ ASHRAE, 2014. 2014 Handbook--Refrigeration. The American
Society of Heating, Refrigerating, and Air-conditioning Engineers,
Inc. Atlanta, Georgia, USA. ISBN 978-1-936504-71-8; ISSN 1930-7195.
    \130\ ICF, 2016h. Market Characterization for Fire Suppression,
Comfort Cooling, Cold Storage, and Household Refrigeration
Industries in the United States. Prepared for the U.S. Environmental
Protection Agency. October 2015.
---------------------------------------------------------------------------

    One commenter, AHRI, indicated manufacturers are developing R-407A
condensing units that could be used in cold storage warehouses,
particularly those less than 3,000 square feet which, as noted in
section VI.A.4.c.v of the proposed rule (81 FR 22853; April 18, 2016),
are subject to DOE energy conservation standards for walk-in coolers
and freezers.
b. What is EPA's final decision?
    For new cold storage warehouses, EPA proposed to change as of
January 1, 2023, the status of the following refrigerants from
acceptable to unacceptable: HFC-227ea, R-125/290/134a/600a (55.0/1.0/
42.5/1.5), R-404A, R-407A, R-407B, R-410A, R-410B, R-417A, R-421A, R-
421B, R-422A, R-422B, R-422C, R-422D, R-423A, R-424A, R-428A, R-434A,
R-438A, R-507A, and RS-44 (2003 composition). In this action, we are
finalizing the status changes that we proposed with no changes. The
change of status determinations for new cold storage warehouses are
summarized in Table 9.

                       Table 9--Change of Status Decisions for New Cold Storage Warehouses
----------------------------------------------------------------------------------------------------------------
               End-use                                    Substitutes                         Listing Status
----------------------------------------------------------------------------------------------------------------
Cold Storage Warehouses (new)........  HFC-227ea, R-125/290/134a/600a (55.0/1.0/42.5/    Unacceptable as of
                                        1.5), R-404A, R-407A, R-407B, R-410A, R-410B, R-  January 1, 2023.
                                        417A, R-421A, R-421B, R-422A, R-422B, R-422C, R-
                                        422D, R-423A, R-424A, R-428A, R-434A, R-438A, R-
                                        507A, and RS-44 (2003 composition).
----------------------------------------------------------------------------------------------------------------

i. How do these unacceptable refrigerants compare to other refrigerants
for this end-use with respect to SNAP criteria?
    Other refrigerants for new cold storage warehouse not subject to
this action are FOR12A, FOR12B, HFC-134a, IKON A, IKON B, KDD6, R-407C,
R-407F, R-437A, R-450A, R-513A, R-717, R-744, RS-24 (2002 composition),
SP34E, THR-02, and THR-03. In the proposed rule, EPA provided
information on the environmental and health risks presented by the
alternatives that are being found unacceptable compared with other
available alternatives that are listed as acceptable (81 FR 22851-52;
April 18, 2016). In addition, a technical support document \131\ that
provides the Federal Register citations concerning data on the SNAP
criteria (e.g., ODP, GWP, VOC, toxicity, flammability) for acceptable
alternatives, as well as those we are finding unacceptable, for new
cold storage warehouses may be found in the docket for this rulemaking
(EPA-HQ-OAR-2015-0663).
---------------------------------------------------------------------------

    \131\ EPA, 2016b. Tables of Alternatives for End-Uses Considered
in the Final Rule, Protection of Stratospheric Ozone: Listing
Modifications for Certain Substitutes under the Significant New
Alternatives Policy Program. September, 2016.
---------------------------------------------------------------------------

    One commenter requested that EPA clarify which refrigerants in the
R-407 series were subject to a change in status, while others
specifically requested that we not change the status of R-407A and R-
407B in cold storage warehouses. We are finalizing a change of status
for the refrigerants we proposed. With respect to the R-407 series
refrigerants in this end-use, EPA only proposed a change of status for
R-407A and R-407B based on our analysis that these two blends posed a
higher overall risk to human health and the environment than other
available refrigerants for this end use. EPA did not propose and is not
taking action in this rule to change the status of R-407C and R-407F in
cold storage warehouses; those refrigerants remain acceptable in this
end-use. EPA has not listed others in the R-407 series, including R-
407D, R-407E and R-407G, and R-407H, acceptable in this end-use.
    For cold storage warehouses, the refrigerants we are listing as
unacceptable have insignificant ODPs, but they have GWPs ranging from
2,090 to 3,990. As shown in Table 10, acceptable alternatives have GWPs
ranging from zero to 1,820.

            Table 10--GWP, ODP, and VOC Status of Refrigerants in New Cold Storage Warehouses \1\ \2\
----------------------------------------------------------------------------------------------------------------
           Refrigerants                  GWP               ODP                  VOC             Listing status
----------------------------------------------------------------------------------------------------------------
R-450A, R-513A, R-717, R-744.....           0-630  0..................  No.................  Acceptable.
IKON A, IKON B, THR-02...........          30-560  0--Not public \3\..  Yes \4\............  Acceptable.
HFC-134a, R-407C, R-407F.........     1,430-1,820  0..................  No.................  Acceptable.
FOR12A, FOR12B, KDD6, R-437A, RS-       920-1,810  0--Not public \3\..  Yes \4\............  Acceptable.
 24 (2002 composition), SP34E,
 THR-03.
R-407A, R-407B, R-410A, R-410B, R-    2,090-2,800  0..................  No.................  Unacceptable.
 421A, R-423A.
R-125/290/134a/600a (55/1/42.5/       2,260-2,730  0..................  Yes \4\............  Unacceptable.
 1.5), R-417A, R-422B, R-422D, R-
 424A, R-438A, RS-44 (2003
 composition).
HFC-227ea, R-421B, R-404A, R-507A     3,190-3,990  0..................  No.................  Unacceptable.
R-422A, R-422C, R-428A, R-434A...     3,080-3,610  0..................  Yes \4\............  Unacceptable.
----------------------------------------------------------------------------------------------------------------
\1\ The table does not include not-in-kind technologies listed as acceptable for the stated end-uses.
\2\ HCFC-22 and several blends containing HCFCs are also listed as acceptable but their use is severely
  restricted by the phasedown in HCFC production and consumption.
\3\ The ODP of one or more alternatives is not published here in order to avoid disclosing information that is
  claimed as confidential business information.
\4\ One or more constituents of the refrigerant are VOC.

    Some of the refrigerant blends not subject to this action, as well
as several of the substitutes for which we are changing the listing
from acceptable to unacceptable, include small amounts of R-290, R-600,
or other substances that are VOCs. These amounts are small and for this
end-use, are not expected to contribute significantly to ground-level
ozone formation.\132\ In the actions where EPA listed these
refrigerants as acceptable or acceptable subject to use conditions, EPA
concluded none of these refrigerants in this end-use pose significantly
greater risk to ground-level ozone formation than other alternative
refrigerants that do not meet the definition of VOC under CAA
regulations (see 40 CFR 51.100(s)) or that are specifically excluded
from that definition for the purpose of developing SIPs to attain and
maintain the NAAQS.
---------------------------------------------------------------------------

    \132\ ICF, 2014a. Assessment of the Potential Impact of
Hydrocarbon Refrigerants on Ground Level Ozone Concentrations.
February, 2014.
---------------------------------------------------------------------------

    The refrigerants listed as acceptable and not subject to this
action are highly volatile and typically evaporate or partition to air,
rather than contaminating surface waters. Their effects on aquatic life
are expected to be small and pose no greater risk of aquatic or
ecosystem effects than those of the refrigerants that are subject to
the status change for this end-use.
    With the exception of R-717, all other acceptable refrigerants, as
well as those that we are listing as unacceptable, are not flammable
and are of low toxicity (e.g., those listed under ASHRAE Standard 34-
2013 are Class A toxicity and Class 1 nonflammable). R-717 is mildly
flammable with a low flame speed; it is classified as a B2L refrigerant
under ASHRAE 34 (2013). R-717 has a long history of use as a
refrigerant in cold storage warehouses and other applications. In the
original SNAP rule, EPA noted ``[R-717] has been used as a medium to
low temperature refrigerant in vapor compression cycles for more than
100 years. Ammonia [R-717] has excellent refrigerant properties, a
characteristic pungent odor, no long-term atmospheric risks, and low
cost. It is, however, mildly flammable and toxic, although it is not a
cumulative poison. OSHA standards specify a 15 minute short-term
exposure limit of 35 ppm for ammonia [R-717].'' (53 FR 13072; March 18,
1994). We further noted its use in various food and beverage processing
and storage applications as well as other industrial applications. In
that rule, we found R-717 acceptable for use in new cold storage
warehouses, concluding that its overall risk to human health and the
environment was not significantly greater than the other alternatives
found acceptable. This conclusion was based on the assumption that the
regulated community adheres to OSHA regulations on such use as well as
standard refrigeration practices, such as ASHRAE Standard 15 and the
IIAR Standard 2,\133\ which are often utilized by local authorities
when setting their own building and safety requirements. See section
VI.A.4.c.iii.(b) of the proposed rule (81 FR 22852; April 18, 2016) for
a discussion on the long history of use of R-717 and our original
decision finding it acceptable in new cold storage warehouses.
---------------------------------------------------------------------------

    \133\ ANSI/IIAR Standard 2-2008 (Addendum B)--American National
Standard for Equipment, Design, & Installation of Closed Circuit
Ammonia Mechanical Refrigerating Systems.
---------------------------------------------------------------------------

    In summary, because the risks other than GWP are not significantly
different for the other available alternatives than for those we
proposed to list as unacceptable, and because the GWPs for the
refrigerants we proposed to list as unacceptable are significantly
higher and thus pose significantly greater risk, we are listing the
following refrigerants as unacceptable: HFC-227ea, R-125/290/134a/600a
(55.0/1.0/42.5/1.5), R-404A, R-407A, R-407B, R-410A, R-410B, R-417A, R-
421A, R-421B, R-422A, R-422B, R-422C, R-422D, R-423A, R-424A, R-428A,
R-434A, R-438A, R-507A, and RS-44 (2003 composition).
ii. When will the status change?
    EPA is establishing a change of status date for the above-listed
refrigerants new cold storage warehouses of January 1, 2023, which the
Agency finds is a reasonable yet expeditious date by which the
technical challenges can be met for a safe and smooth transition to
alternatives. This amount of time is needed particularly considering
the various equipment types that could be employed to provide the
cooling necessary for new cold storage warehouses and the requirement
for many of these equipment types to meet energy conservation standards
while undergoing such a transition. Although acceptable alternatives,
particularly R-717, are widely used, EPA recognizes based on comment
that R-717 is not an option due to technical or compliance constraints
at some facilities. For these facilities, the user would need the time
to investigate the use of other alternatives and to design, and
possibly certify to DOE energy conservation standards, equipment using
the chosen alternative. As discussed in the proposed rule (81 FR 22850;
April 18, 2016), in some cases, R-717 may not have been chosen based on
building code and regulatory restrictions that might have eliminated
its use. As also discussed there, and as supported by comment,
technologies are under development that can overcome some such
limitations; for example, newly-developed low-charge R-717 systems

can overcome building code and regulatory challenges that arise when
large charge sizes would otherwise be required, although we recognize
that such equipment may not be allowed in certain jurisdictions or may
not be practical in certain situations. EPA is establishing a January
1, 2023, status change date in part to allow these technologies to more
fully mature and become more fully available in the market. In addition
to these technologies, because a wide variety of other equipment types
can be applied at a cold storage warehouse, and some such equipment is
subject to DOE energy conservation requirements, EPA expects that this
period of time will allow acceptable alternatives to become more fully
available for cold storage warehouses. For locations and applications
that would otherwise use HFC blends subject to status change, primarily
R-404A, R-410A and R-507A, time is needed to develop equipment with
other alternative refrigerants or address the technical challenges of
using R-717 or other alternatives that are not subject to the proposed
change in status. As explained in section VI.A.4.c.v of the proposed
rule (81 FR 22853; April 18, 2016), certain types of equipment
potentially applied in cold storage warehouses are subject to energy
conservation standards, and hence time will be required to design, test
and certify equipment for those standards, while at the same time using
acceptable alternatives.
c. How is EPA responding to comments?
    EPA received comments on various topics including, the proposed
status change date of January 1, 2023, the refrigerants proposed for
status change, the acceptability of other refrigerants, and requests
for subdividing the category and limiting the status changes based on
those subdivisions.
    Commenters included AHRI, an industry organization; CARB, a state
agency; Daikin and Zero Zone, equipment manufacturers; Chemours,
Honeywell, and National Refrigerants, three chemical producers; and
NRDC, IGSD, and EIA, three environmental organizations.
    We have grouped comments together and responded to the issues
raised by the comments in the sections that follow, or in a separate
Response to Comments document which is included in the docket for this
rule (EPA-HQ-OAR-2015-0663).
i. Substitutes and End-Use Proposed
    Comment: Daikin suggested that EPA subdivide the cold storage
warehouse end-use into ``Indirect Expansion Refrigeration System[s]''
and ``Direct Expansion Refrigeration System[s].'' They did not suggest
any different decisions for the former. For the latter, they
recommended that R-410A remain acceptable, noting that it (along with
R-407C and R-407F) is also used in direct systems. Daikin commented
that both direct and indirect systems may be used, even at the same
facility. Daikin said that customer requirements will typically
determine the refrigeration system and that these requirements depend
on ``the use conditions, structure of the building and climatic
considerations among other factors.''
    Response: EPA is not subdividing the end-use as suggested. For
direct systems, two of the three refrigerants they mentioned as being
typically used--R-407C and R-407F--remain acceptable as proposed.
Daikin did not provide any indication of why in direct systems R-410A
would be required as opposed to these refrigerants not subject to
status change. The commenter did not indicate specifically what use
conditions, building structures, climates or other technical barriers
warranted subdividing the end-use as suggested, nor did the commenter
offer reasons for not changing the status of one particular refrigerant
in one of those subdivisions.
    Comment: Zero Zone agreed with EPA's explanation of the distinction
between cold storage warehouses and IPR.
    Response: EPA thanks the commenter for this comment.
    Comment: Zero Zone claimed that EPA should consider small cold
storage warehouses--those with a footprint of 3,000 square feet (279
square meters) or less--as fitting in the retail food refrigeration
end-use. They noted that DOE and California regulations cover such
items, whether they are cold storage warehouses or they are used for
retail food refrigeration, as walk-in coolers or freezers. They felt
that equipment manufacturers supplying equipment that meets such
definitions of walk-in coolers or freezers ``need to be able to supply
the same equipment'' regardless of whether they would be classified as
a cold storage warehouse or retail food refrigeration under SNAP. They
said that equipment manufacturers should not have to ``ascertain what
product will be in the building.'' Zero Zone stated that both R-407A
and R-407B should remain acceptable, especially if EPA did not treat
small cold storage warehouses as part of the retail food refrigeration
end use. AHRI also stated that R-407A and R-407B should be acceptable
in cold storage warehouses because the same unit cooler equipment,
whether used in a cold storage warehouse or in retail food
refrigeration, would need to comply with DOE energy efficiency
standards for walk-in coolers and freezers. They stated manufacturers
are preparing systems that use R-407A for small cold storage
warehouses. Daikin, NRDC, and IGSD indicated that R-407C and R-407F are
also used in cold storage warehouses. National Refrigerants asked EPA
to list all R-407 series refrigerants acceptable for cold storage
warehouses to provide additional options and to ``eliminate confusion
in the industry'' and ``ease compliance for technicians and equipment
owners by giving them the flexibility to utilize their R-407 preferred
refrigerant.''
    Response: EPA disagrees that certain cold storage warehouses should
be included as part of the retail food refrigeration end-use. EPA
established status changes for three retail food refrigeration end-use
categories in a previous rule and stated that equipment in these
categories of the SNAP end-use could also be subject to DOE's energy
conservation standards for Walk-In Coolers and Freezers (80 FR 82902;
July 20, 2015). Likewise, we noted in our proposed rule (81 FR 22853;
April 18, 2016) that small cold storage warehouses could also be
covered by these DOE standards. We disagree that R-407A and R-407B
should remain acceptable despite the indication that some products are
being designed using the former or for a manufacturer's preference to
use the same refrigerant in different end-uses. We are particularly
confused by the inclusion of R-407B in the comments from Zero Zone and
AHRI requesting we find it acceptable, as we changed the status of that
refrigerant for all categories of new retail food refrigeration
addressed in a previous rule (80 FR 42870; July 20, 2015). If we were
to treat small cold storage warehouses as retail food refrigeration, as
these commenters also suggest, R-407B would be subject to status
change. Several alternatives that remain acceptable for cold storage
warehouses are also acceptable for various retail food refrigeration
end-use categories. For instance, R-407C and R-407F, which as noted are
being used in some cold storage warehouses, are also acceptable for the
retail food refrigeration remote condensing unit end-use category.
Manufacturers who wish to use only one refrigerant may do so and to the
extent they are already using a refrigerant that is subject to status
change in the cold storage warehouse end-use, EPA finds no evidence
that these or other acceptable alternatives cannot be adopted by the

2023 status change date while continuing to meet DOE energy
conservation standards.
    Further, we disagree that to eliminate confusion, ease compliance,
or provide flexibility we should list all R-407 series refrigerants as
acceptable. EPA reviews refrigerants individually and is aware that
manufacturers, users, and owners make it their business to know the
exact refrigerant they are using, since they currently are aware that
not all R-407 series refrigerants are acceptable in this or any other
end-use. Just because two or more refrigerants are made up of the same
components \134\ does not mean they present the same overall risk to
human health and the environment. Indeed, R-407 and other series
refrigerants are made up of components having different flammability,
toxicity, GWP, and other characteristics considered by SNAP, making a
knowledge of specific composition critical to evaluating associated
risk.
---------------------------------------------------------------------------

    \134\ All R-407 series refrigerants are composed of HFC-32, HFC-
125 and HFC-134a.
---------------------------------------------------------------------------

    Comment: EIA, NRDC, IGSD, Chemours, and CARB supported EPA changing
the status to unacceptable of those refrigerants we proposed for such
change in new cold storage warehouses.
    Response: EPA thanks the commenters for these comments.
    Comment: Chemours felt that R-407C and R-407F should also be listed
as unacceptable stating there are multiple alternatives. Daikin
compared R-410A to R-448A and R-449A, arguing that because R-410A can
reduce the amount of refrigerant needed by 30 percent, the total GWP-
weighted emissions would be similar to that of R-448A and R-449A. CARB
stated that R-717, especially in low-charge units, and R-744 could be
used. EIA suggested that EPA continue to evaluate additional
refrigerants and consider those for status change, mentioning HFC-134a,
R-407C, R-407F, R-450A, and R-513A.
    Response: EPA's proposal was limited to determinations for the
specific refrigerants proposed which pose significantly greater risk
than other available refrigerants. We cannot take final action changing
the status of additional refrigerants without first performing the
necessary analysis of the SNAP criteria and providing notice and an
opportunity for comment.
    In response to the suggestion that we list additional specific
refrigerants as unacceptable, we note that at least two--R-407C and R-
407F--are currently used in cold storage warehouses. In addition to
considering the SNAP criteria in determining whether to propose action
to change the status of an acceptable substitute, we also need to
consider whether there are other alternatives available. Although we
recognize that alternatives such as R-717 and R-744 are available for
certain types of equipment in certain applications in the cold storage
warehouses end-use, the information available at this time does not
indicate that there are available alternatives for all types of
equipment in all types of applications.
    Comment: AHRI, Zero Zone, and Honeywell all supported an EPA action
to list R-448A and R-449A as acceptable for cold storage warehouses.
Honeywell noted that they are already being implemented in similar
equipment for the supermarket systems end-use category. On the other
hand, NRDC and IGSD urged EPA to find these two refrigerants
unacceptable, while EIA asked EPA to ``[r]equest advance comments on
changing the listing status'' of these two HFC/HFO blends as well as R-
450A and R-513A for new cold storage warehouses.
    Response: These comments suggesting that EPA take action to list
additional substitutes as acceptable or to change the listing status of
already-listed substitutes go beyond the scope of this rulemaking. As
noted previously, EPA may in the future issue a new proposal to change
the status of additional refrigerants in this end use after considering
what other alternatives are available and performing an analysis using
the SNAP criteria. Regarding the request that EPA substitutes not
already on one of the lists as acceptable or unacceptable, EPA notes
that R-448A and R-449A have been submitted to the SNAP Program for
review, but EPA has not yet issued a proposed decision for these
refrigerants or issued a Notice of Acceptability.
ii. Change of Status Date
    Comment: EIA, NRDC, IGSD, and Chemours supported EPA's proposed
2023 status change date for new cold storage warehouses.
    Response: EPA thanks the commenters for these comments.
    Comment: Honeywell suggested a status change date of January 1,
2019, based on the fact that several options, including R-407F, R-717,
and R-744, are acceptable for new cold storage warehouses. They also
indicated R-448A and R-449A are potential options that could be
implemented by January 1, 2019.
    Response: EPA agrees that many of the acceptable refrigerants not
subject to status change have been and can continue to be used in many
types of equipment for many of the applications for new cold storage
warehouses. EPA established a status change date of 2023 based on the
time required to address the number of different equipment types and
system designs used for cold storage warehouse and to redesign, and if
required recertify as compliant with DOE energy conservation standards.
EPA has determined that a change of status date of January 1, 2023, is
reasonable and expeditious in light of the various DOE energy
conservation standards that must be met (and for which equipment needs
to be designed and manufactured), the need to further assess currently
acceptable nonflammable and low toxicity alternatives in specific
applications, and the need to develop safe practices and institute
State and local code changes if required for flammable and higher
toxicity alternatives for certain equipment where the application and/
or the location limits the use of flammable or higher toxicity
refrigerants at this time. The commenter did not provide a discussion
of these equipment design and application issues or an indication of
how those can be addressed by 2019.
    Comment: CARB suggested a status change date of 2020, noting that
low-charge R-717 systems address issues with that refrigerant's use in
cold storage warehouses and where it cannot be used, R-744 or other
non-toxic, low-GWP refrigerants could be used.
    Response: The commenter did not provide technical support that a
change of status date of January 1, 2020, was feasible. The commenter
does not provide any detail on the use of R-744 in those applications
where R-717 is not an option, and we are not aware that its use has
been demonstrated for all of those applications. We are aware that R-
744 is being used for new cold storage warehouses in cascade and
secondary loop systems with R-717. However, we did not see similar
evidence it can be used in a direct system (i.e., not in a cascade or
secondary loop system with R-717) in the various equipment types and
designs used for this end-use.
    Comment: Zero Zone stated that the change of status for R-404A and
R-507A should be January 1, 2025, because those refrigerants offer the
low-glide properties desired for flooded or liquid overfeed systems.
They compared these to R-450A and R-513A--both of which are acceptable
in new cold storage warehouses and are not subject to the change in
status--which they described as also having low glide but low
volumetric efficiency. They felt the time was necessary ``to allow
technology and chemical companies to come up with a solution to this
design issue.''
    Response: The commenter did not provide any information that it was
not

technically feasible to transition away from R-404A and R-507A until
January 1, 2025. No explanatory timeline or past experience was
provided that indicated how long it might take to resolve the issues
they described. Other commenters have noted that R-407C and R-407F,
which are also high-glide blends, are used in cold storage warehouses.
Although they did not mention whether those were specifically used in
the flooded evaporator systems described, we are not aware and Zero
Zone has not provided any information on why they could not be used.
Zero Zone also did not discuss why single-component (no glide)
refrigerants including R-717 and R-744 could not be used in the types
of systems with which they are concerned. Finally, the commenter noted
that there are some low-glide blends available, but did not provide the
detail on the steps needed to redesign equipment to account for the low
volumetric efficiency they indicated for those available alternatives
and why those steps could not be completed before January 1, 2025.
iii. SNAP Review Criteria
    Comment: Daikin believed that ``it is important to note the
equipment's potential total environmental impact (i.e. refrigerant
quantity multiplied with GWP), not only the refrigerant's GWP value.''
As such, they stated that R-410A could reduce the total charge size up
to 30 percent compared to R-404A.
    Response: EPA interprets this comment to be based on the SNAP
review criteria of ``atmospheric effects,'' which is discussed above in
section II.E.1. In a previous proposed rule and in the response to
comments document for the associated final rule, we discussed the
possibility of allowing refrigerants with a higher GWP in low-charge
systems. In particular, we stated ``given the high GWP of these
refrigerants compared to other refrigerants that are available in
[supermarket systems], we do not believe that use with a small charge
size adequately addresses the greater risk they pose.'' (79 FR 46148;
August 6, 2014). The same consideration is applicable here for R-410A,
even if systems were designed to reduce the total charge size as Daikin
says is possible. Use in a lower-charge system does not guarantee lower
overall emissions. If catastrophic losses occurred in a system
employing R-410A or other high-GWP refrigerants, the emissions in
CO2-equivalent terms could be more than if a lower-GWP
refrigerant were used in the same or a similarly low-charge design. For
instance, an acceptable alternative could be used in a secondary loop
design, reducing the amount of that refrigerant used for the given
application.
7. Change of Status for Certain HFC Refrigerants for New Retail Food
Refrigeration (Refrigerated Food Processing and Dispensing Equipment)
a. Background
i. What is the affected end-use?
    In the SNAP July 2015 rule (80 FR 42902), EPA clarified that
``equipment designed to make or process cold food and beverages that
are dispensed via a nozzle, including soft-serve ice cream machines,
`slushy' iced beverage dispensers, and soft-drink dispensers'' was not
included as part of the retail food refrigeration end-use categories
specifically identified in that final rule. EPA clarified that this
equipment is part of a separate end-use category within the retail food
refrigeration end-use. This end-use category, ``refrigerated food
processing and dispensing equipment,'' is covered in this section of
the final rule. For an overview of this end-use category, please refer
to section VI.A.4.d.i of the proposed rule (81 FR 22854-55; April 18,
2016).
    One commenter, UTC, pointed out that certain soft-serve and other
frozen dairy treats may not fall within the technical definition of
ice-cream due to milk fat content, but that such products ``are handled
like ice-cream and shake products from an operational point of view.''
UTC also stated that a creamer dispenser (refrigerated unit dispensing
creamer in a dosed amount) and bulk milk dispensers (refrigerated unit
holding a container of milk that dispenses through a small nozzle when
the handle is lifted) would fit in this category as well. EPA's use of
``including'' in its description of the type of equipment that falls
under this end use indicates that the list was not intended to be
exclusive. EPA considers the types of equipment identified by UTC,
which dispense products through a nozzle, to fit within the end-use.
ii. What other types of equipment are used for similar applications but
are not covered by this section of the rule?
    As noted in section VI.A.4.d.i of the proposed rule (81 FR 22854;
April 18, 2016) certain types of equipment, including water coolers and
stand-alone retail food refrigeration units, do not fall within this
end-use category.
iii. What Refrigerants Are Used in Retail Food Refrigeration
(Refrigerated Food Processing and Dispensing Equipment)
    EPA discussed which refrigerants were acceptable in the
refrigerated food processing and dispensing equipment end-use category
in section VI.A.4.d.i of the proposed rule (81 FR 22855; April 18,
2016). While numerous refrigerants are acceptable in this end use, as
noted by the comments from UTC, R-404A is typically used for freezing
applications and HFC-134a for refrigerated applications.
    In comments submitted on the proposal, AHRI and UTC discussed the
potential use of R-448A and R-449A in this end-use category, and AHRI
urged EPA to find these blends acceptable. Other information claimed as
CBI indicated the potential to transition R-404A applications within
this end-use category to those refrigerants. Tecumseh also urged EPA to
list these two refrigerants acceptable as well as R-452A. EPA has
received submissions for these three refrigerants. Concurrent with this
rule, EPA is listing R-448A, R-449A, and R-449B as acceptable without
use conditions for new refrigerated food processing and dispensing
equipment. We are currently reviewing R-452A for this end-use.
b. What is EPA's final decision?
    For new refrigerated food processing and dispensing equipment, EPA
proposed to change as of January 1, 2021, the status of the following
refrigerants from acceptable to unacceptable: HFC-227ea, KDD6, R-125/
290/134a/600a (55.0/1.0/42.5/1.5), R-404A, R-407A, R-407B, R-407C, R-
407F, R-410A, R-410B, R-417A, R-421A, R-421B, R-422A, R-422B, R-422C,
R-422D, R-424A, R-428A, R-434A, R-437A, R-438A, R-507A, RS-44 (2003
formulation). In this action, we are finalizing the status changes we
proposed with no changes. The change of status determinations for new
refrigerated food processing and dispensing equipment are summarized in
Table 11.

 Table 11--Change of Status Decisions for New Retail Food Refrigeration
         [Refrigerated food processing and dispensing equipment]
------------------------------------------------------------------------
           End-use                   Substitutes          Listing status
------------------------------------------------------------------------
Retail food refrigeration     HFC-227ea, KDD6, R-125/    Unacceptable as
 (refrigerated food            290/134a/600a (55.0/1.0/   of January 1,
 processing and dispensing     42.5/1.5), R-404A, R-      2021.
 equipment) (new only).        407A, R-407B, R-407C, R-
                               407F, R-410A, R-410B, R-
                               417A, R-421A, R-421B, R-
                               422A, R-422B, R-422C, R-
                               422D, R-424A, R-428A, R-
                               434A, R-437A, R-438A, R-
                               507A, RS-44 (2003
                               formulation).
------------------------------------------------------------------------

i. How do these unacceptable refrigerants compare to other refrigerants
for this end-use with respect to SNAP criteria?
    For new refrigerated food processing and dispensing equipment, the
substitutes that will remain listed as acceptable pose lower overall
risk to human health and the environment than the refrigerants we are
listing as unacceptable. Acceptable refrigerants include: FOR12A,
FOR12B, HFC-134a, IKON A, IKON B, R-426A, RS-24 (2002 formulation), R-
450A, R-513A, R-744, SP34E, THR-02 and THR-03. In the proposed rule (81
FR 22855-22856; April 18, 2016) and SNAP Notice 31 (81 FR 32241; May
23, 2016), EPA provided information on the environmental and health
risks presented by the alternatives that are being found unacceptable
compared with other available alternatives that are listed as
acceptable. Also, concurrent with this rule, EPA is listing R-448A, R-
449A and R-449B acceptable for new refrigerated food processing and
dispensing equipment. A technical support document \135\ that provides
the Federal Register citations concerning data on the SNAP criteria
(e.g., ODP, GWP, VOC, toxicity, flammability) for acceptable
alternatives, as well as those we are finding unacceptable, for new
refrigerated food processing and dispensing equipment may be found in
the docket for this rulemaking (EPA-HQ-OAR-2015-0663).
---------------------------------------------------------------------------

    \135\ EPA, 2016b. Tables of Alternatives for End-Uses Considered
in the Final Rule, Protection of Stratospheric Ozone: Listing
Modifications for Certain Substitutes under the Significant New
Alternatives Policy Program. September, 2016.
---------------------------------------------------------------------------

    The refrigerants we are listing as unacceptable have GWPs ranging
from 1,770 to 3,990. As shown in Table 12, acceptable alternatives have
GWPs ranging from one to 1,510.

               Table 12--GWP, ODP, and VOC Status of Refrigerants in New Retail Food Refrigeration
                         [Refrigerated food processing and dispensing equipment] \1\ \2\
----------------------------------------------------------------------------------------------------------------
          Refrigerants                 GWP                  ODP                    VOC           Listing status
----------------------------------------------------------------------------------------------------------------
HFC-134a, R-448A, R-449A, R-            1-1,430  0........................  No...............  Acceptable.
 449B, R-450A, R-513A, R-744.
FOR12A, FOR12B, IKON A, IKON B,        30-1,510  0--Not public \3\........  Yes \4\..........  Acceptable.
 R-426A, RS-24 (2002
 composition), SP34E, THR-02,
 THR-03.
R-407A, R-407B, R-407C, R-407F,     1,770-2,800  0........................  No...............  Unacceptable.
 R-410A, R-410B, R-421A.
KDD6, R-125/290/134a/600a (55/1/    1,810-2,730  0........................  Yes \4\..........  Unacceptable.
 42.5/1.5), R-417A, R-422B, R-
 422D, R-424A, R-437A, R-438A,
 RS-44 (2003 composition).
HFC-227ea, R-404A, R-421B, R-       3,190-3,990  0........................  No...............  Unacceptable.
 507A.
R-422A, R-422C, R-428A, R-434A.     3,080-3,610  0........................  Yes \4\..........  Unacceptable.
----------------------------------------------------------------------------------------------------------------
\1\ The table does not include not-in-kind technologies listed as acceptable for the stated end-uses.
\2\ HCFC-22 and several blends containing HCFCs are also listed as acceptable but their use is severely
  restricted by the phasedown in HCFC production and consumption.
\3\ The ODP of one or more alternatives is not published here in order to avoid disclosing information that is
  claimed as confidential business information.
\4\ One or more constituents of the refrigerant are VOC.

    Some of the refrigerant blends not subject to this action, as well
as several of the substitutes for which we are changing the listing
from acceptable to unacceptable, include small amounts of VOC such as
R-290 (propane) and R-600 (n-butane). These amounts are small, and for
this end-use category are not expected to contribute significantly to
ground-level ozone formation.\136\ In the actions where EPA listed
these refrigerants as acceptable, EPA concluded none of these
refrigerants in this end-use pose significantly greater risk to ground-
level ozone formation than other alternative refrigerants that do not
meet the definition of VOC under CAA regulations (see 40 CFR 51.100(s))
or that are specifically excluded from that definition for the purpose
of developing SIPs to attain and maintain the NAAQS.
---------------------------------------------------------------------------

    \136\ ICF, 2014a. Assessment of the Potential Impact of
Hydrocarbon Refrigerants on Ground Level Ozone Concentrations.
February, 2014.
---------------------------------------------------------------------------

    The refrigerants not subject to this action are highly volatile and
typically evaporate or partition to air, rather than contaminating
surface waters. Their effects on aquatic life are expected to be small
and pose no greater risk of aquatic or ecosystem effects than those of
the refrigerants that are subject to the proposed status change for
this end-use.
    For this end-use category, all of the refrigerants, including those
which we are listing as unacceptable, are not flammable (e.g., those
listed under ASHRAE Standard 34-2013 are class 1 flammability).
Additionally, as discussed at section VI.A.4.d.iii.(c) of the proposed
rule (81 FR 22856; April 18, 2016) and in SNAP Notice 31 (81 FR 32245-
46; May 23, 2016), the toxicity of the refrigerants we are listing as
unacceptable is comparable to that of other alternatives that are
acceptable in this end-use.
    In summary, because the risks other than GWP are not significantly
different for the other available alternatives than for those we
proposed to list as unacceptable, and because the GWPs for the
refrigerants we proposed to list as unacceptable are significantly
higher and thus pose significantly greater risk, we are listing the
following refrigerants as unacceptable: HFC-227ea, KDD6, R-125/290/
134a/600a (55.0/1.0/42.5/1.5), R-404A, R-407A, R-407B, R-407C, R-

407F, R-410A, R-410B, R-417A, R-421A, R-421B, R-422A, R-422B, R-422C,
R-422D, R-424A, R-428A, R-434A, R-437A, R-438A, R-507A, RS-44 (2003
formulation).
i. When will the status change?
    EPA proposed and is establishing a change of status date for
refrigerated food processing and dispensing equipment of January 1,
2021, which the Agency finds is a reasonable yet expeditious date by
which the technical challenges can be met for a safe and smooth
transition to alternatives particularly considering the need for
equipment to comply with any sanitation and safety standards while
continuing to maintain the properties, characteristics and quality of
the food or beverage provided by the equipment. As discussed below and
in our response to comments, EPA relied on information from an
equipment manufacturer claimed as CBI that estimated different
conversion periods based on two refrigerants--specifically three years
for R-448A and five years for R-744--and the technical hurdles posed by
those refrigerants. While current efforts are focused on using those
two refrigerants, there are a number of other refrigerants listed as
acceptable for this end-use that manufacturers may also choose to use.
However, there is no information that suggests that a conversion period
for these other refrigerants would be any quicker than that for R-448A
and R-744.
    To address what alternatives might be available and when, comments
were provided by manufacturers and an association representing
manufacturers regarding certain refrigerants not currently acceptable
in this end-use category. Information was provided for R-448A and R-
449A, two HFC/HFO blends designed to mimic the properties of R-404A,
and one manufacturer and an association representing manufacturers
requested we find them acceptable for this end-use category. As noted
above, concurrent with this rule EPA is listing R-448A, R-449A, and R-
449B acceptable in this end-use. EPA views the interest expressed by
comments to be indicative of the progress being made in this end-use
category and the likely future use of R-448A, R-449A, or R-449B. As
noted above, information claimed as CBI indicates a transition to one
of these refrigerants could occur by January 1, 2021, and was being
planned by a manufacturer of equipment for this end-use category. EPA
discussed the status of these HFC/HFO blends and the availability of
their HFO components in a previous action (80 FR 42870; July 20, 2015).
For instance, we concluded then that there was ample supply of these
refrigerants and we pointed out that Emerson, a major supplier of
compressors and other components, was qualifying these refrigerants for
use in its products. Others have followed suit. For instance, Tecumseh
has approved R-449A as an acceptable alternative to R-404A and was in
the process of releasing R-449A compressors for use in remote
condensing units.\137\ This technology and know-how could then likely
translate into the refrigerated food processing and dispensing
equipment market, thereby allowing a transition by the January 1, 2021,
change of status date.
---------------------------------------------------------------------------

    \137\ Tecumseh, 2016. ``Tecumseh Outlines Position on
Refrigerant Transition.'' January 25, 2016. This document is
accessible at http://www.tecumseh.com/en/North-America/Newsroom/Press-Releases/2016/2016-AHR-Press-Release.
---------------------------------------------------------------------------

    Information was also supplied by equipment manufacturers regarding
the use of R-290 specifically or HCs generically in this equipment. An
environmental organization indicated that equipment using R-290 is
already being used in markets outside the United States and recommended
finding R-290 and R-600a acceptable subject to use conditions. EPA has
not received a submission for these refrigerants specifically for the
refrigerated food processing and dispensing equipment end-use category.
If in the future we decide to list these as acceptable, they would be
included in a Notice of Acceptability published in the Federal
Register, or, if we were to propose finding them acceptable subject to
use restrictions or unacceptable, we would publish a separate proposed
rule.
    Equipment manufacturers also submitted comments on some but not all
of the acceptable refrigerants not proposed for status change. One
manufacturer deemed HFC-134a as not appropriate for their equipment
while a second manufacturer indicated that refrigerant is typically
used for refrigerated (as opposed to freezing) applications in this
end-use category. Based on these comments, EPA recognizes that HFC-134a
is available for a portion of this end-use category, but additional
time would be required for it, or other acceptable alternatives, to be
considered available for all of this end-use category.
    One manufacturer provided technical information regarding the
challenges with using R-744 although as mentioned above information
claimed as CBI indicated at least one equipment manufacturer was
planning to transition to that refrigerants. A state agency indicated
that low-GWP refrigerants including R-744 ``are currently available for
refrigeration in retail food.'' Also, a group of companies,
Refrigerants, Naturally!, stated that ``there are natural refrigerant
alternatives available on the market'' for dispensing equipment. The
former comment discussed retail food refrigeration generally, rather
than the refrigerated food processing and dispensing equipment category
specifically. The latter comment only mentioned ``dispensing
equipment'' and did not mention equipment that may also process food
and beverages as well as dispensing it. As such EPA views these
statements as indicative of the availability of alternatives for a
portion but not necessarily all of the equipment within this end-use
category.
    EPA finds however that the progress using R-744 is far enough along
to consider that it will be available for the vast majority, if not
all, of the equipment in this end-use category that are using
refrigerants subject to status change by January 1, 2021. As noted in
the proposal (81 FR 22856; April 18, 2016), the Coca-Cola Company,
which purchases equipment in this and other retail food refrigeration
end-use categories, has announced their plans to convert to non-HFC
technologies for all new cold-drink equipment by 2015, and selected R-
744 as its refrigerant of choice.\138\ The Coca-Cola Company has
already placed over 1.4 million HFC-free units globally (80 FR 42919-
42920; July 20, 2015) and it was reported that the company would only
``narrowly miss'' its 2015 target to be HFC-free.\139\ The demand
created by this company for R-744 in this end-use category (as well as
for commercial refrigeration equipment in other end use categories
addressed in a previous rule) is expected to increase the availability
of R-744 components over the next several years. The time provided by
the status change date will allow other components to be developed, for
example to provide R-744 compressors designed for this end-use category
rather than the ``continuous, longer run systems'' as mentioned by an
equipment manufacturer. Further, as this company purchases equipment
from other suppliers, EPA expects that similar equipment, and the
components used by such equipment, will become more

widely available in the market. While today's action allows less time
than the five-year transition time estimated by a manufacturer in
information claimed as CBI for a full transition of R-404A equipment to
R-744, EPA believes based on experience to date and the market built by
the demand created by the Coca-Cola Company will allow for a faster
transition than the commenter estimated.
---------------------------------------------------------------------------

    \138\ Coca-Cola, 2014. ``Coca-Cola Installs 1 Millionth HFC-Free
Cooler Globally, Preventing 5.25MM Metrics Tons of CO2.'' January
22, 2014. This document is accessible at http://www.coca-colacompany.com/press-center/press-releases/coca-cola-installs-1-millionth-hfc-free-cooler-globally-preventing-525mm-metrics-tons-of-co2.
    \139\ Refrigeration and Air Conditioning Magazine, 2015. ``Coca
Cola to narrowly miss HFC-free global refrigeration target.'' March
20, 2015. This document is accessible at www.racplus.com/news/cocacola-to-narrowly-miss-hfc-free-global-refrigerationtarget/8680290.article.
---------------------------------------------------------------------------

    Based on this information claimed as CBI and other comments as
discussed above, we find that a January 1, 2021, change of status date
is necessary to provide a reasonable yet expeditious time for the
transition to acceptable alternatives to occur.
c. How is EPA responding to comments?
    EPA received several comments from individuals and organizations
with various interests in the refrigerants industry. Comments addressed
the proposed status change date of January 1, 2021, the refrigerants
proposed for status change, the technical challenges of using
refrigerants remaining acceptable and other refrigerants that may be
listed as acceptable in the future, energy efficiency, and other rules
and standards that may apply to equipment in this end-use category.
    Commenters included AHRI, an industry organization; Arkema and
Chemours, chemical producers; CARB, a state agency; EIA, NRDC and IGSD,
environmental organizations; and Stoelting, Tecumseh and UTC, equipment
and component manufacturers. Additional comments claimed as CBI were
submitted.
    We have grouped comments together and responded to the issues
raised by the comments in the sections that follow, or in a separate
Response to Comments document which is included in the docket for this
rule (EPA-HQ-OAR-2015-0663).
i. Substitutes and End-Use Proposed
    Comment: UTC was in general agreement with how EPA defined this
end-use category, but pointed out that ``soft-serve and other frozen
dairy treats may not fall within the technical definition of ice-cream
due to milk fat content.'' They also stated that ``it appears a creamer
dispenser (refrigerated unit dispensing creamer in a dosed amount) and
bulk milk dispensers (refrigerated unit holding a container of milk
that dispenses through a small nozzle when the handle is lifted) would
fit in this category as well.''
    Response: As noted previously in section VI.A.7.a.i, EPA agrees
that the type of equipment identified by the commenter falls within
this end-use.
    Comment: UTC, Refrigerants Naturally!, Chemours, EIA, NRDC, and
IGSD agreed with EPA's proposal to change the status of refrigerants
for this end-use category.
    Response: EPA thanks the commenters for the comments.
    Comment: AHRI and UTC both claimed that the number of currently
listed acceptable substitutes is limited and that EPA should list R-
448A and R-449A as acceptable for this end-use category. Tecumseh
suggested listing those two refrigerants and R-452A as acceptable.
    Response: As shown in Table 12, multiple refrigerants are
acceptable for this end-use category. After the proposal was published,
but before the comment period closed, EPA added another alternative to
the list of acceptable refrigerants in this end-use category,
specifically R-513A. R-448A, R-449A, R-449B, and R-452A have been
submitted to the SNAP Program for review. Concurrent with this rule,
EPA is finding R-448A, R-449A, and R-449B acceptable for new
refrigerated food processing and dispensing equipment. EPA has not
proposed or made a final listing decision for R-452A in the
refrigerated food processing and dispensing equipment end-use category.
If in the future we decide to list this as acceptable, it would be
included in a Notice of Acceptability published in the Federal
Register. Likewise, if we were to propose finding it acceptable,
subject to use restrictions or unacceptable, we would publish a
separate proposed rule.
    Comment: Responding to EPA's statement in the preamble to the
proposed rule that currently HCs such as R-290, R-600a and R-443A are
not listed as acceptable in this end-use category, UTC and Stoelting
identified technical challenges affecting the potential use of these
refrigerants in this end-use category. EIA recommended that EPA find R-
290 and R-600a acceptable, subject to use conditions as soon as
possible. They indicated that manufacturers are already making R-290
refrigerated dispensing systems abroad pointing to equipment offered by
several companies, and felt this demonstrates a change in status is
feasible.
    Response: EPA did not propose and is not taking action regarding
the use of HCs in this end-use category at this time. In any future
action EPA may take addressing the use of HCs in this end-use, EPA
would consider relevant technical information such as the availability
of equipment operating on R-290 in markets outside the United States.
    Comment: An initiative of a group of companies encouraged EPA to
find HFC-134a unacceptable ``for systems where there are
environmentally safe, low GWP alternatives.'' Information claimed as
CBI indicated that a manufacturer plans to transition from HFC-134a
after converting its R-404A equipment.
    Response: EPA did not propose to change the status of HFC-134a for
this end-use category and we are not taking such action today. While we
recognize that there are plans to transition from HFC-134a by at least
one manufacturer, the information provided did not offer sufficient
basis to determine when alternatives would be available for the limited
applications within this end-use category that rely on HFC-134a.
ii. Change of Status Date
    Comment: Three commenters submitted information regarding the
technical challenges of using certain refrigerants that have been
submitted to EPA for review but for which EPA has not made a listing
decision. UTC stated that the time to transition different products
``may vary based on technical challenges with product sensory
characteristics and differences in dispense rate requirements.'' They
indicated that a challenge for using R-448A, which they proposed should
be found acceptable, existed with the compressor discharge temperature
which might reduce the compressor reliability. Stoelting requested an
extension (of unspecified time) or exemption to continue to use R-404A.
They stated that ``R-448 or R-449 have an inherent temperature glide of
8 [deg]F [4.4 [deg]C] or more'' that causes two issues. They stated
that they could not ``account for the fractionation'' of such
refrigerants in equipment with flooded evaporators. They also stated
that meeting the temperature variances required (+/-1 [deg]F [0.56
[deg]C]) would be difficult and lead to a ``too cold/firm'' region and
a ``too warm/soft'' region. Information submitted and claimed as CBI
estimated that at least three years was needed to transition to R-448A,
if it is found acceptable.
    Response: EPA recognizes that challenges exist with any transition
and based on the technical information provided for this end-use EPA is
establishing a change of status date of January 1, 2021. EPA notes that
there are refrigerants currently listed as acceptable that would
alleviate or eliminate the concern regarding temperature glide that
Stoelting mentioned. For instance, R-744 as a pure substance does not
have a temperature glide, although separate limitations were discussed
by UTC as explained in the following comment.

Also, while R-450A is zeotropic, it has a low temperature glide that
presumably can be addressed based on past experience with R-404A,
another low-glide zeotropic blend. In addition, R-513A is an azeotrope
with no temperature glide.
    With respect to the other issues concerning R-448A discussed by
UTC, concurrent with this rule, EPA is listing R-448A as acceptable in
this end-use. As noted above, information provided and claimed as CBI
indicates a transition to R-448A is feasible by the change of status
date established.
    Comment: UTC emphasized that sufficient time is needed to
transition equipment to refrigerants not subject to status change. They
described multiple challenges with using R-744, which is currently
listed as acceptable. One challenge they described is the additional
space required in the heat exchangers and that this additional space
requirement must be balanced with the need to minimize increases in
footprints which would be difficult to accommodate in many foodservice
settings that utilize this equipment. The commenter further indicated
the challenges with ``compressor availability, compressor operating
envelope, refrigerant controls availability (in our capacity range),
footprint, and cost.'' Another challenge with R-744 noted was the need
to design for higher operating pressures and a more complex cooling
cycle. The commenter also stated that additional work on the compressor
designs was needed to develop models that are suited for the varying
cooling demands of this type of equipment as opposed to other
applications where R-744 compressors are used. For example, UTC stated
that ``R-744 compressors have been traditionally designed for
continuous, longer run system.'' CARB however stated that R-744 is
currently available for retail food refrigeration, arguing for a 2020
status change date, while information claimed as CBI indicated at least
one equipment manufacturer was already planning to convert to R-744 in
the future. This information claimed as CBI by an equipment
manufacturer estimated that they would need at least a five-year
timeframe to transition to R-744.
    Response: EPA agrees that some challenges exist when converting to
R-744, but the technical progress to date in using this refrigerant in
various applications indicates these challenges can be met by the
change of status date. Although some components are available, R-744
components have not yet become widely available and could not currently
satisfy the entire market for this end-use category by CARB's suggested
January 1, 2020 date. Nonetheless, although specific comments
suggesting the solutions to the technical concerns raised were not
provided, the transition by the Coca-Cola Company and other comments
indicate that such solutions exist and can be implemented. As discussed
in section VI.A.7.b.ii above, EPA finds that R-744 will be available
for most if not all of the equipment in this end-use category by the
change of status date, and sees various paths forward in the case that
it is not fully available for all such equipment.
iii. Relationship With Other Rules
    Comment: In response to EPA's request for comment on applicable DOE
energy conservation standards for equipment in this end-use category,
UTC indicated that there are currently no DOE directives or
requirements for this equipment. They also indicated the American
Society for Testing and Materials (ASTM International) was developing a
test standard for this equipment, implying such a standard might form
the basis of future DOE rulemaking. They also indicated that European
rules covering ice-cream and shake machines are being drafted.
    Response: EPA thanks the commenter for this information regarding
the development of testing standards and the current status of DOE and
European requirements for this equipment. We did not consider possible
future action by ASTM or DOE in establishing a change of status date
for this end-use category, but if one or both those actions occur, EPA
could consider it at that time.
iv. Industry Standards and Codes
    Comment: UTC provided a list of multiple industry standards,
including ones from the Canadian Standards Association (CSA,) UL, and
IEC that apply to this equipment. The commenter did not indicate how
the information was related to the proposal.
    Response: EPA thanks the commenter for the information regarding
standards.
8. Change of Listing Status for Certain HFC Refrigerants for New
Household Refrigerators and Freezers
a. Background
i. What is the affected end-use?
    Household refrigerators, freezers and combination refrigerator/
freezers are intended primarily for residential use, although they may
be used outside the home. The designs and refrigeration capacities of
equipment vary widely. Household refrigerators and freezers are
composed of three main categories of equipment. Household freezers only
offer storage space at freezing temperatures, while household
refrigerators only offer storage space at non-freezing temperatures.
Products with both a refrigerator and freezer in a single unit are most
common. In addition to the three main categories of equipment, other
small refrigerated household appliances exist (i.e., chilled kitchen
drawers, wine coolers, and mini-fridges) that are also within this end
use. Household refrigerators and freezers have all refrigeration
components integrated, and for the smallest types, the refrigeration
circuit is entirely brazed or welded. These systems are charged with
refrigerant at the factory and typically require only an electricity
supply to begin operation.
    The 2014 ASHRAE Handbook of Refrigeration provides an overview of
food preservation in regards to household refrigerators and freezers.
Generally, a storage temperature between 32 and 39 [deg]F (0 to 3.9
[deg]C) is desirable for preserving fresh food. Humidity and higher or
lower temperatures are more suitable for certain foods and beverages.
Wine chillers, for example, are frequently used for storing wine, and
have slightly higher optimal temperatures from 45 to 65 [deg]F (7.2 to
18.3 [deg]C). Freezers and combination refrigerator-freezers that are
designed to store food for long durations have temperatures below 8
[deg]F (-13.3 [deg]C) and are designed to hold temperatures near 0 to 5
[deg]F (-17.7 to -15 [deg]C). In single-door refrigerators, the optimum
conditions for food preservation are typically warmer than this due to
the fact that food storage is not intended for long-term storage.
    DOE energy conservation standards apply to household refrigerators
and freezers, as discussed in section VI.A.9.b.ii.
i. What refrigerants are used in household refrigerators and freezers?
    The following alternatives are currently acceptable for new
household refrigerators and freezers: FOR12A, FOR12B, HFC-134a, HFC-
152a, IKON A, IKON B, KDD6, R-125/290/134a/600a (55.0/1.0/42.5/1.5), R-
290, R-404A, R-407C, R-407F, R-410A, R-410B, R-417A, R-421A, R-421B, R-
422A, R-422B, R-422C, R-422D, R-424A, R-426A, R-427A, R-428A, R-434A,
R-437A, R-438A, R-441A, R-450A, R-513A, R-507A, R-600a, RS-24 (2002
formulation), RS-44 (2003 formulation), SP34E, THR-02 and THR-03. Of
those, R-290, R-441A and R-600a are acceptable, subject to use
conditions.

    Currently, the most commonly used refrigerant in the United States
for household refrigerators and freezers is R-134a, an HFC with a GWP
of 1,430. However, throughout many parts of the world, R-600a with a
GWP of approximately four is the most commonly used refrigerant and
there are ongoing efforts to help facilitate the adoption and continued
use of R-600a in this industry globally.\140\ The European Union (EU)
banned the use of HFCs with a GWP greater than 150 (which includes R-
134a) for household refrigerators and freezers as of January 1,
2015.\141\ R-600a has been used in Europe for approximately two
decades. Throughout parts of Asia, Africa, and South America, R-600a is
the dominant refrigerant for this end-use. In its 2014 assessment
report,\142\ the TEAP's Refrigeration, Air Conditioning and Heat Pumps
Technical Options Committee (RTOC) projects that by 2020 about 75
percent of new household refrigerators globally will use R-600a, a
small percentage will use HFOs, and the rest will use HFC-134a. There
are other alternatives that may be determined to work well in this end
use. For example, R-450A and R-513A, which EPA has listed as acceptable
for use in this end-use (79 FR 62863, October 21, 2014; 80 FR 42053,
July 16, 2015, respectively), were designed to match the
characteristics and performance of HFC-134a.
---------------------------------------------------------------------------

    \140\ ORNL, 2015. ORNL's JUMP Challenge: JUMP in to Advance Tech
Innovation! Presented by Brian Fricke, Oak Ridge National
Laboratory. November 17, 2015.
    \141\ EU, 2014. Regulation (EU) No 517/2014 of the European
Parliament and of the Council of 16 April 2014 on fluorinated
greenhouse gases and repealing Regulation (EC) No 842/2006.
Available online at: http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=uriserv:OJ.L_.2<IP_ADDRESS>5.01.ENG.
    \142\ RTOC, 2015. 2014 Report of the Refrigeration, Air-
Conditioning and Heat Pumps Technical Options Committee. Available
at: http://conf.montreal-protocol.org/meeting/mop/mop-27/presession/Background%20Documents%20are%20available%20in%20English%20only/RTOC-Assessment-Report-2014.pdf.
---------------------------------------------------------------------------

    In addition to R-600a, EPA previously found a number of other
flammable HC refrigerants including R-290 and R-441A and R-600a as
acceptable, subject to use conditions in household refrigerators and
freezers (76 FR 78832, December 20, 2011; 80 FR 19454, April 10, 2015).
b. What is EPA's final decision?
    For new household refrigerators and freezers, EPA proposed to
change as of January 1, 2021, the status of the following refrigerants
from acceptable to unacceptable: FOR12A, FOR12B, HFC-134a, KDD6, R-125/
290/134a/600a (55.0/1.0/42.5/1.5), R-404A, R-407C, R-407F, R-410A, R-
410B, R-417A, R-421A, R-421B, R-422A, R-422B, R-422C, R-422D, R-424A,
R-426A, R-428A, R-434A, R-437A, R-438A, R-507A, RS-24 (2002
formulation), RS-44 (2003 formulation), SP34E, and THR-03. In this
action, we are finalizing the status changes as proposed. The change of
status determinations for new household refrigerators and freezers:

                  Table 13--Change of Status Decisions for Household Refrigerators and Freezers
----------------------------------------------------------------------------------------------------------------
                 End-use                                  Substitutes                       Listing status
----------------------------------------------------------------------------------------------------------------
Household refrigerators and freezers      FOR12A, FOR12B, HFC-134a, KDD6, R-125/290/  Unacceptable as of January
 (new only).                               134a/600a (55.0/1.0/42.5/1.5), R-404A, R-   1, 2021.
                                           407C, R-407F, R-410A, R-410B, R-417A, R-
                                           421A, R-421B, R-422A, R-422B, R-422C, R-
                                           422D, R-424A, R-426A, R-428A, R-434A, R-
                                           437A, R-438A, R-507A, RS-24 (2002
                                           formulation), RS-44 (2003 formulation),
                                           SP34E, and THR-03.
----------------------------------------------------------------------------------------------------------------

i. How do these unacceptable refrigerants compare to other refrigerants
for this end-use with respect to SNAP criteria?
    Other refrigerants for new household refrigerators and freezers are
HFC-152a, IKON A, IKON B, THR-02; R-513A, R-450A, R-290, R-441A and R-
600a. In the proposed rule, EPA provided information on the
environmental and health risks presented by the alternatives that are
being found unacceptable compared with other alternatives listed as
acceptable (81 FR 22858; April 18, 2016). In addition, a technical
support document \143\ that provides the Federal Register citations
concerning data on the SNAP criteria (e.g., ODP, GWP, VOC, toxicity,
flammability) for acceptable alternatives as well as those we are
finding unacceptable for new household refrigerators and freezers may
be found in the docket for this rulemaking (EPA-HQ-OAR-2015-0663).
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    \143\ EPA, 2016b. Tables of Alternatives for End-Uses Considered
in the Final Rule, Protection of Stratospheric Ozone: Listing
Modifications for Certain Substitutes under the Significant New
Alternatives Policy Program. September, 2016.
---------------------------------------------------------------------------

    The refrigerants we are listing as unacceptable through this action
have insignificant ODP and they have GWPs ranging from 920 to 3,990. As
shown in Table 14, the other alternatives, listed as acceptable or as
acceptable, subject to use conditions, have GWP ranging from three to
630.

     Table 14--GWP, ODP, and VOC Status of Refrigerants in New Household Refrigerators and Freezers \1\ \2\
----------------------------------------------------------------------------------------------------------------
          Refrigerants                 GWP                  ODP                    VOC           Listing status
----------------------------------------------------------------------------------------------------------------
IKON A, IKON B, R-290, R-441A,            3-560  0--Not public \3\........  Yes \4\..........  Acceptable.
 R-600a, THR-02.
HFC-152a.......................             124  0........................  No...............  Acceptable.
R-450A, R-513A.................         600-630  0........................  No...............  Acceptable.
HFC-134a.......................           1,430  0........................  No...............  Unacceptable.
FOR12A, FOR12B, R-426A, RS-24         920-1,510  0--Not public \3\........  Yes \4\..........  Unacceptable.
 (2002 composition), SP34E, THR-
 03.
R-407C, R-407F, R-410A, R-410B,     1,770-2,630  0........................  No...............  Unacceptable.
 R-421A.
KDD6, R-125/290/134a/600a (55/1/    1,810-2,730  0........................  Yes \4\..........  Unacceptable.
 42.5/1.5), R-417A, R-422B, R-
 422D, R-424A, R-437A, R-438A,
 RS-44 (2003 composition).
R-404A, R-421B, R-507A.........     3,190-3,990  0........................  No...............  Unacceptable.
R-422A, R-422C, R-428A, R-434A.     3,080-3,610  0........................  Yes \4\..........  Unacceptable.
----------------------------------------------------------------------------------------------------------------
\1\ The table does not include not-in-kind technologies listed as acceptable for the stated end-uses.
\2\ HCFC-22 and several blends containing HCFCs are also listed as acceptable but their use is severely
  restricted by the phasedown in HCFC production and consumption.
\3\ The ODP of one or more alternatives is not published here in order to avoid disclosing information that is
  claimed as confidential business information.
\4\ One or more constituents of the refrigerant are VOC.

    Three substitutes that remain acceptable, subject to use
conditions, R-290, R-600a, and R-441A, are HCs or a blend of HCs. R-290
and R-600a are VOCs while R-441A is a blend composed primarily of
compounds that are VOC. EPA's analysis indicates that their use as
refrigerants in this end-use is not expected to contribute
significantly to ground level ozone formation.\144\ In the action in
which EPA listed these refrigerants as acceptable, subject to use
conditions (80 FR 19454; April 10, 2015), EPA concluded none of these
refrigerants as used in this end-use pose significantly greater risk to
ground-level ozone formation than other alternative refrigerants that
are not VOCs or that are specifically excluded from the definition of
VOC under CAA regulations (see 40 CFR 51.100(s)) addressing the
development of SIPs to attain and maintain the NAAQS.
---------------------------------------------------------------------------

    \144\ ICF, 2014a. Assessment of the Potential Impact of
Hydrocarbon Refrigerants on Ground Level Ozone Concentrations.
February, 2014.
---------------------------------------------------------------------------

    The refrigerants not subject to this action are highly volatile and
typically evaporate or partition to air, rather than contaminating
surface waters. Their effects on aquatic life are expected to be small
and pose no greater risk of aquatic or ecosystem effects than those of
the refrigerants that are subject to the status change for this end-
use.
    With the exception of HFC-152a, R-290, R-600a and R-441A, all other
refrigerants listed as acceptable, including those we are listing as
unacceptable, are not flammable. R-290 and R-600a, which are HCs, and
R-441A, which is a blend of HCs, are classified as A3 refrigerants by
ASHRAE Standard 34-2013, indicating that they have low toxicity and
high flammability, while HFC-152a is classified as an A2 refrigerant,
indicating that it has low toxicity and low flammability. To address
flammability, EPA listed these R-290, R-441A and R-600a as acceptable,
subject to use conditions. The use conditions include conditions
consistent with industry standards, limits on charge size, and
requirements for warnings and markings on equipment to inform consumers
and technicians of potential flammability hazards. Our assessment and
listing decisions (76 FR 78832; December 20, 2011 and FR 80 19454;
April 10, 2015) found that the overall risk, including the risk due to
flammability with the use conditions, is not significantly greater than
for other refrigerants listed as acceptable at that time. EPA found
HFC-152a acceptable for new household refrigerators and freezers in the
original SNAP rule indicating ``[a]lthough HFC-152a is flammable, a
risk assessment demonstrated it could be used safely in this end-use''
(59 FR 13081; March 18, 1994). Toxicity is not a significant concern
for the refrigerants we are listing as unacceptable. Their toxicity is
comparable to that of other alternatives that are acceptable in this
end-use. The refrigerants subject to the status change and the
refrigerants not subject to the status change, if listed under ASHRAE
34 (2013), are classified as Class A refrigerants (lower toxicity).
    In summary, because the risks other than GWP are not significantly
different for the other available alternatives than for those we
proposed to list as unacceptable, and because the GWPs for the
refrigerants we proposed to list as unacceptable are significantly
higher and thus pose significantly greater risk, we are listing the
following refrigerants as unacceptable: FOR12A, FOR12B, HFC-134a, KDD6,
R-125/290/134a/600a (55.0/1.0/42.5/1.5), R-404A, R-407C, R-407F, R-
410A, R-410B, R-417A, R-421A, R-421B, R-422A, R-422B, R-422C, R-422D,
R-424A, R-426A, R-428A, R-434A, R-437A, R-438A, R-507A, RS-24 (2002
formulation), RS-44 (2003 formulation), SP34E, and THR-03.
ii. When will the status change?
    As proposed, EPA is establishing a change of status date for new
household refrigerators and freezers of January 1, 2021. There are
technical challenges that must be met for a safe and smooth transition
to alternatives, particularly considering the likely use of one or more
of the flammable alternatives. The primary step that must occur for a
transition is product design work for alternative refrigerants, drawing
from current models used both in the United States and elsewhere. For
those designing with flammable refrigerants, this would include
complying with the use conditions EPA established when listing those
refrigerants as acceptable (76 FR 78832; December 20, 2011, and FR 80
1954; April 10, 2015). Although some models have recently and others
are currently transitioning,
    EPA recognizes that manufacturers will need time to continue
product design work for alternative refrigerants, drawing from current
models used both in the United States and elsewhere.
    Household refrigerators are subject to DOE energy conservation
standards and will need to be tested to demonstrate compliance with
those standards.\145\ EPA noted in a previous action that ``we do not
have a practice in the SNAP program of including energy efficiency in
the overall risk analysis'' but also pointed out that ``[w]e do,
however, consider issues such as technical needs for energy efficiency
(e.g., to meet DOE standards) in determining whether alternatives are
`available.' '' (80 FR 42921; July 20, 2015). Hence, we find that the
need for household refrigerator and freezers to meet DOE energy
efficiency standards plays a part in determining the availability of
alternatives and factors into our decision on the applicable change of
status date.
---------------------------------------------------------------------------

    \145\ DOE's previous energy conservation rulemaking for this
end-use was finalized in 2011 with a compliance date of September
15, 2014 (76 FR 57516; September 15, 2011).
---------------------------------------------------------------------------

    With a change of status date of 2021, the evidence presented
indicates that current models--already meeting the current DOE
standards--when redesigned for alternative refrigerants are expected to
continue to meet those existing standards. In fact, comments indicate
an increase in energy efficiency with some of the acceptable
alternatives, some of which have been implemented in products both in
the U.S. market and globally. See for example comments from Electrolux
and NRDC. Furthermore, as the typical compliance period for DOE energy
efficiency regulations is three years from the date issued, a status
change date over four years from today gives manufacturers should
provide a more than adequate period of time to redesign models to meet
such standards with an alternative refrigerant. This time frame also
allows manufacturers time to redesign models considering the use
conditions that must be met if a flammable acceptable alternative is
chosen, as discussed above.
    We understand however that there may be limitations with regard to
the availability of testing facilities in the event that, in the midst
of this implementation of new models with alternative refrigerants, the
energy efficiency requirements were to change in a manner that required
redesigning models to meet the new efficiency standards DOE has not
initiated the process under which new energy efficiency standards would
be promulgated. Commenters have suggested that this process could begin
as early as 2017 with an eventual compliance date of 2024 or 2025.
Therefore, at this point in time it is not evident that there will be
any constraint on laboratory availability to meet the January 1, 2021,
status change date in this rule. Should DOE finalize new energy
efficiency standards for household refrigerators-freezers in the next
few years, EPA could consider at that time whether laboratory
availability

issues might affect the transition to alternative refrigerants by the
2021 change of status date.
c. How is EPA responding to comments?
    EPA received several comments from organizations with various
interests in the household refrigerators and freezers end-use. Several
commenters commented on the proposed January 1, 2021, change of status
date. Other comments focused on substitutes and end-use proposed,
industry standards and codes, and general comments such as the need for
technician training.
    Commenters included AHAM, a trade association; and three equipment
manufacturers, Whirlpool, Sub Zero, and Electrolux. EPA also received
comments from Arkema and Chemours, chemical producers; NRDC, IGSD and
EIA, environmental organizations; UL, a safety consulting and
certification company; and CARB, a state agency.
    We have grouped comments together and responded to the issues
raised by the comments in the sections that follow, or in a separate
Response to Comments document which is included in the docket for this
rule (EPA-HQ-OAR-2015-0663).
i. Substitutes and End-Use Proposed
    Comment: AHAM noted that although alternatives have been approved
for and can be used in refrigerators and freezers, the only viable
alternative is R-600a and there are no available ``drop-ins.'' AHAM
also noted that while the appliance industry is moving to replace HFC
refrigerants in their products and has produced and sold hundreds of
millions of units safely around the world using HC alternatives,
factories must be reengineered, and education, logistics and disposal
systems would need to be established to manage the safe transportation,
servicing and disposal of flammable refrigerants in North America.
Whirlpool also commented that major manufacturing changes are required
across the industry to achieve widespread use of flammable
refrigerants. Three environmental organizations, NRDC, IGSD, and EIA,
along with a state government agency, CARB, and a chemical producer,
Chemours, supported EPA's proposal to change the status of HFC-134a in
this end-use.
    Response: EPA appreciates comments submitted in support of the
proposed rule and thanks commenters. As to AHAM's comments that there
are no ``drop-in'' substitutes for this end use, although EPA prefers
not to use the term ``drop-in,'' it is sometimes used by various
parties to refer to the circumstance where one refrigerant can be used
in place of another without any modification to the relevant piece of
refrigeration equipment. While equipment manufacturers may prefer to
use HC refrigerants as they do in other markets, EPA believes that R-
450A and R-513A may meet the characteristics that AHAM uses to define
``drop-in'' replacements. These are non-flammable and were developed to
have characteristics similar to R-134a. That said, EPA finds that the
change of status date provides sufficient time for redesigning to use
HC refrigerants if so preferred by equipment manufacturers.
ii. Change of Status Date
    Comment: Chemours, a chemical producer, supported the change of
status for the refrigerants proposed to be listed as unacceptable,
noting that it has sufficient supply of commercial replacement
solutions with comparable or improved energy efficiency compared to the
substitutes subject to the proposed status change. UL commented on the
proposed change of status for HFC-134a for use in this end-use, stating
it did not expect to be adversely impacted by any testing or retesting
of refrigerators and freezers due to proposed provision.
    Response: EPA acknowledges UL's statement that under the proposed
timeline for the change of status of R-134a they do not anticipate any
difficulty in providing laboratory capacity to perform any testing
needed for newly designed refrigerators and freezers and we have
considered this information in determining an appropriate change of
status date. In addition, we considered whether there was sufficient
manufacturing capacity for substitutes by Chemours and other chemical
producers in order to meet the established change of status date and
determined that production would be more than sufficient for a January
1, 2021, change of status date.
    Comment: Several commenters commented on the proposed January 1,
2021, change of status date for household refrigerators and freezers.
AHAM and Sub Zero suggested that a complete transition date should be
no earlier than 2024. AHAM noted that, while the industry is moving to
replace HFC refrigerants in products, this transition process is
expensive, time consuming, and industry faces technical challenges.
AHAM and Whirlpool suggested that the proposed change of status date
would create significant difficulties in designing products with
flammable refrigerants while also meeting DOE energy conservation
standards and charge size limitations for flammable refrigerants in the
UL refrigerators and freezers safety standard. AHAM and Sub Zero
suggested there would be a small environmental impact from moving the
change of status date to 2024. Whirlpool also recommended a transition
date of 2024 due to the design and engineering changes that would be
necessary. Electrolux noted that they could transition out of HFC based
refrigerants by January 1, 2021, if the charge size limit on HC
refrigerants could be increased. NRDC, IGSD, and EIA urged EPA to
maintain the proposed status change date of January 1, 2021, and noted
requests for extended delays are completely unwarranted given that
refrigerator manufacturers have offered models with R-600a for over a
decade outside the United States.
    Response: EPA appreciates points raised by AHAM, Sub Zero, and
Whirlpool and understands that challenges exist; however we do not
agree that additional time beyond what was proposed is needed. We
understand that time is needed for adapting certain model designs to
the U.S. market but do not believe the commenters have provided
sufficient information to indicate that more time than what EPA
proposed would be needed. Although the comments did not provide a
detailed analysis of what steps are required to complete a transition
and how long each step takes, and whether steps can occur
simultaneously or must occur in series, we find that much component
equipment development can occur at the same time as other product
design work. In other words, as certain components become available,
appropriate units could be redesigned using those components,
prototypes could be built and tested, and final designs could be
manufactured. While redesigns and prototypes are developed, additional
components can be developed as needed for other designs. Indeed, once
product models are designed, testing and certification could take place
while additional models are designed.
    We agree with NRDC, IGSD, and EIA that a status change date of
January 1, 2021, can be met, and will allow sufficient time for
manufacturers to redesign any products that require additional
engineering to meet this rule. EPA notes that R-600a is currently being
used in more than 500 million household refrigerator and freezer units
worldwide, including some units in the United States.\146\
Additionally, although changing the charge size limit for hydrocarbon
refrigerants as mentioned by Electrolux is beyond the scope of this

rule, many manufacturers have already identified a portion of their
products that they could redesign using R-290 under the existing limit.
EPA notes that refrigeration and AC equipment manufacturers are not
required to use any of the flammable refrigerants listed as acceptable,
subject to use conditions in this action; we expect that those who
choose to do so will plan accordingly for any changes required at the
factory and in the designs of the products they manufacture. We note
that R-450A and R-513A, which are not subject to status change, will
not require as many changes to the equipment design particularly since
these are nonflammable and operate with similar characteristics to HFC-
134a.
---------------------------------------------------------------------------

    \146\ (TEAP, 2015).
---------------------------------------------------------------------------

    Regarding the comment that there would be little environmental
impact by delaying the change of status date until 2024, we do not
consider that as part of the analysis for determining the appropriate
change of status date. We consider environmental effects, as part of
the SNAP review criteria for determining whether safer alternatives are
available. Once we have determined that other alternatives can be used
that pose less risk we look at the technical challenges of a transition
and the availability of alternatives to identify a reasonable but
expeditious change of status date that reflects when alternatives can
be used broadly within the end-use. Regarding Arkema's specific
suggestion for a change of status date of 2025, EPA does not agree that
equipment being hermetically sealed justifies a later change of status
date. As noted, EPA has determined that other alternatives pose less
risk than those for which the status is being changed can reasonably be
used earlier than 2025. Even assuming that the commenter is correct
that alternatives may be used in a manner that would pose even less
risk at a later date, such an assumption would not justify delaying the
change of status date. Manufacturers could still choose to manufacture
new equipment that is hermetically sealed in 2025 and beyond.
iii. Industry Standards and Codes
    Comment: AHAM, Whirlpool, NRDC, IGSD, and EIA discussed charge size
limitations for flammable refrigerants in the UL refrigerators and
freezers safety standard. Whirlpool and Electrolux noted the need for a
new safety standard that would replace the current UL standard that has
established the charge size limit of HC-based refrigerants to 57 g.
Electrolux suggested that this charge size limit should be harmonized
with the IEC 60335-2-40 standard in place in the European Market at 150
g. Arkema stated that building codes do not yet support use of
flammable materials at a sufficient charge size. CARB mentioned the
$5.2 million commitment announced on June 2, 2016, by DOE, AHRI, and
ASHRAE discussed previously to fund vital research that will establish
a more robust fact base about the properties and uses of flammable
refrigerants. This new research program will help provide the technical
knowledge needed to facilitate and accelerate the safe use of these
refrigerants. NRDC and IGSD commented that, in addition to finalizing
the change of status date for HFC-134a in new household refrigerators
and freezers, EPA should revisit the charge size limit of 57 g for HC
refrigerants used in any refrigerator, freezer, or combination
refrigerator and freezer for each circuit. NRDC and IGSD also
recommended that UL and AHAM ``review the technical justification for
such a wide gulf between U.S. and international safety standards and
close it as soon as possible.'' Similarly, EIA commented that ``the
current UL 250 charge size limit of 57 g of R-600a is effectively and
unnecessarily prohibiting market penetration of low-GWP hydrocarbon
systems in the U.S. . . . Even with the current overly restrictive UL
standard in place, manufacturers have R-600a based systems on the U.S.
market, though the charge size is a major restriction to refrigerator
volume, or substantially increases the price if dual compressor systems
are used to make a standard sized U.S. refrigerator.'' EIA recommended
that, while the UL 471 harmonization process to replace UL 250
continues, EPA should recognize the 150 g charge size limit under the
currently recognized International Electrochemical Commission (IEC)
standard (IEC 60335-2-89) as an acceptable use condition for the sale
of household refrigerators and freezers using HCs in the United States.
EIA believes this will help support the proposed change of status date
of January 1, 2021, for HFC-134a. EIA referenced their October 2015
petition to the Agency requesting that EPA incorporate by reference the
IEC standard 60335-2-89 as the basis for charge size limitations as use
conditions for R-290 and R-600a in household refrigerators and
freezers.
    Response: EPA understands the interest in reconsidering safe charge
limits and the potential for UL and IEC standards to be harmonized. EPA
understands that there are efforts in this direction underway. EPA is
encouraged by the June 2016 announcement by DOE, ASHRAE and AHRI and
understands that other stakeholders have been invited to join this
effort. While there may be opportunities to make changes to applicable
standards, and subsequently change the use conditions that currently
apply, such changes are beyond the scope of this rule. If and when
those standards are harmonized, EPA could consider whether to revise
the SNAP listing consistent with the new standards. This action is
based on the Agency's view that the other alternatives including those
acceptable to use conditions are feasible for use, as demonstrated by
several manufacturers, including GE and BOSCH. We understand that other
manufacturers are earlier in the process of designing equipment using
alternatives that remain acceptable and EPA has established a change of
status date of January 1, 2021 to allow time for manufacturers to
address the technical challenges.
iv. Other Suggestions or Requests
    Comment: AHAM recommended that service personnel must be trained to
adequately protect themselves and consumers from activities that may be
routine for handling equipment with non-flammable refrigerants but that
are not protective when servicing equipment with flammable HC
refrigerants. AHAM commented that repairing leaks or replacing/filling
refrigerant lines will involve new training techniques that must be
developed and communicated.
    Response: EPA is not taking action in this rulemaking regarding the
use of flammable refrigerants for this end-use and thus this comment is
outside the scope of this rulemaking. However, we note that we are
aware that at least two organizations--RSES and the ESCO Institute--
have developed technician training programs in collaboration with
refrigeration equipment manufacturers and users that address safe use
of flammable refrigerant substitutes. In addition, EPA has reviewed
several training programs provided as part of SNAP submissions from
persons interested in flammable refrigerant substitutes. The Agency
intends to update the test bank for technician certification under CAA
section 608 as we have done previously, and will consider including
additional questions on flammable refrigerants. By adding such
questions to the test bank, EPA would supplement but would not replace
technician training programs currently provided by non-government
entities. EPA will seek additional information and guidance on how best
to incorporate this content through a

separate process outside the scope of this final rule.

B. Motor Vehicle Air Conditioning

1. Background
    The vehicle types that are addressed in this action include limited
types of HD vehicles, specifically, MDPVs,\147\ HD trucks, and complete
HD vans.\148\ EPA has previously listed HFO-1234yf as acceptable,
subject to use conditions, in light-duty (LD) motor vehicles and trucks
(76 FR 17490; March 29, 2011).
---------------------------------------------------------------------------

    \147\ Defined at 40 CFR 86.1801-03.
    \148\ MVAC systems provide passenger comfort cooling for LD cars
and trucks, HD vehicles (large pick-ups, delivery trucks,
recreational vehicles, and semi-trucks), off-road vehicles, buses,
and rail vehicles. EPA is not addressing other types of HD vehicles,
off-road vehicles, buses, or trains in this action.
---------------------------------------------------------------------------

    The types of HD vehicles addressed in this action are in many ways
more similar to LD vehicles than they are to the HD vehicles with a
higher gross vehicle weight rating (GVWR), which is a measure of the
combined curb (empty) weight and cargo carrying capacity of the truck.
Table 15 outlines the HD vehicle weight classifications commonly used.
MDPVs,\149\ HD pickup trucks, and HD vans are Class 2b and 3 vehicles
with GVWRs between 8,501 and 14,000 lb. These vehicle types are similar
to LD vehicles technologically and most are manufactured in a similar
manner to LD vehicles by companies with major light-duty markets in the
United States.\150\ Ford, General Motors, and Fiat Chrysler Automobiles
(FCA) produce approximately100 percent of HD pickup trucks and
approximately 95 percent of HD vans, with Daimler and Nissan producing
the remaining approximately five percent of HD vans.\151\ In many
cases, these types of HD vehicles are versions of their LD
counterparts.\152\ For example, the Silverado 1500, Ram 1500, and Ford
F-150 are the LD counterparts of the HD Silverado 2500/3500, Ram 2500/
3500, and Ford F-250/F-350/F-450 pickup trucks.\153\ The primary
difference between HD pickup trucks and vans and their LD counterpart
vehicles is that HD pickups and vans are occupational or work vehicles
that are designed for much higher towing and payload capabilities
compared to LD pickups and vans.
---------------------------------------------------------------------------

    \149\ MDPVs are classified as HD vehicles based on their GVWR,
but due to their similarities to LD vehicles they are subject to the
GHG emissions standards established for LD trucks.
    \150\ This is more broadly true for HD pickup trucks than vans
because every manufacturer of HD pickup trucks also makes LD pickup
trucks, while only some heavy-duty van manufacturers also make
light-duty vans (80 FR 40148; July 13, 2015).
    \151\ EPA, 2015. Draft Regulatory Impact Analysis: Proposed
Rulemaking for Greenhouse Gas Emissions and Fuel Efficiency
Standards for Medium- and Heavy-Duty Engines and Vehicles--Phase 2.
EPA-420-D-15-900. June 2015. Available at http://www3.epa.gov/otaq/climate/documents/420d15900.pdf.
    \152\ ICCT, 2015. International Council on Clean Transportation:
Regulatory Considerations for Advancing Commercial Pickup and Van
Efficiency Technology in the United States. Available online at:
http://www.theicct.org/us-commercial-pickups-vans-efficiency-technology.
    \153\ ICF, 2015. Market Characterization of the U.S. Motor
Vehicle Air Conditioning Industry, U.S. Foams Industry, U.S.
Aerosols Industry, and U.S. Commercial Refrigeration Industry. July,
2015.

                                                         Table 15--Vehicle Weight Classification
--------------------------------------------------------------------------------------------------------------------------------------------------------
              Class                       2b               3                4                5                6                7                8
--------------------------------------------------------------------------------------------------------------------------------------------------------
GVWR (lb)........................    8,501-10,000    10,001-14,000    14,001-16,000    16,001-19,500    19,501-26,000    26,001-33,000          >33,000
--------------------------------------------------------------------------------------------------------------------------------------------------------

    All types of HD vehicles can be sold as ``complete'' or
``incomplete'' vehicles (76 FR 57259-60; September 15, 2011). Complete
vehicles are sold by vehicle manufacturers to end-users with no
secondary manufacturer making substantial modifications prior to
registration and use. Incomplete vehicles are sold by vehicle
manufacturers to secondary manufacturers without the primary load-
carrying device or container attached. See section VI.B.1 of the
proposed rule for additional information on HD vehicles and the vehicle
types within the MVAC end-use that are addressed in this action.
    Section 608(c) of the CAA prohibits the knowing venting, release or
disposal of all refrigerants by any person maintaining, servicing,
repairing or disposing of an appliance or IPR in a manner which permits
the refrigerant to enter the environment, except for certain substitute
refrigerants that have been specifically exempted from this venting
prohibition under CAA section 608(c)(2). MVAC end-of-life disposal and
recycling specifications are also covered under section 608 of the CAA
and our regulations issued under that section of the Act, which are
codified at subpart F of 40 CFR part 82. Additionally, CAA section 609
establishes standards and requirements regarding servicing of MVAC
systems. Under section 609, no person repairing or servicing motor
vehicles for consideration \154\ may perform any service on an MVAC
that involves the refrigerant without properly using approved
refrigerant recovery or recovery and recycling equipment and no such
person may perform such service unless such person has been properly
trained and certified. This action will not have a direct impact on
EPA's regulations under section 609. For further information on the
relationship between this action and other federal rules, see section
VI.B.6 of the proposed rule (81 FR 22866-67; April 18, 2016).
---------------------------------------------------------------------------

    \154\ Service for consideration means receiving something of
worth or value to perform service, whether in money, credit, goods,
or services.
---------------------------------------------------------------------------

2. What is EPA's final decision?
    As proposed, EPA is listing HFO-1234yf as acceptable, subject to
use conditions, in MVAC systems for newly manufactured MDPVs, HD pickup
trucks, and complete HD vans. The use conditions are detailed in
section VI.B.2.b, ``What are the final use conditions?''. EPA sought
comment and information on listing HFO-1234yf as acceptable subject to
use conditions for some incomplete HD vans. One commenter provided
information to EPA and EPA will consider that information to determine
whether to take further action regarding the listing of HFO-1234yf for
use in incomplete HD vans.
    As explained in section VI.B.1, section 608 of the CAA prohibits
the knowing venting, release or disposal of all refrigerants by any
person maintaining, servicing, repairing or disposing of an appliance
or IPR in a manner which permits the refrigerant to enter the
environment, except for certain substitute refrigerants that have been
specifically exempted from this venting prohibition. Because HFO-1234yf
has not been exempted from the venting prohibition in any end use, such
knowing releases of HFO-1234yf in the course of maintaining, servicing,
repairing or disposing of MVAC systems of MDVPs, HD pickup trucks, and
complete HD vans addressed in this action is prohibited.

a. How does HFO-1234yf compare to other refrigerants for these MVAC
applications with respect to SNAP criteria?
    Available refrigerants for newly manufactured MDPVs, HD pickup
trucks, and complete HD vans include HFC-134a, HFC-152a,\155\ and
CO2.\156\ There are also several blend refrigerants that are
listed as acceptable for new HD MVAC systems, subject to use
conditions, including the HFC blends SP34E and R-426A (also known as
RS-24) and the HCFC blends, R-416A (also known as HCFC Blend Beta or
FRIGC FR12), R-406A, R-414A (also known as HCFC Blend Xi or GHG-X4), R-
414B (also known as HCFC Blend Omicron), HCFC Blend Delta (also known
as Free Zone), Freeze 12, GHG-X5, and HCFC Blend Lambda (also known as
GHG-HP). HFC-134a is the refrigerant most widely used today in HD MVAC
systems; however, given the change of status for HFC-134a for LD
vehicles, it is likely that the manufacturers of these similar vehicle
types will also consider transitioning to another alternative which is
listed as acceptable for LD vehicles. All MVAC refrigerants that are
acceptable for use are listed as acceptable subject to use conditions.
For each listed refrigerant, the use conditions require labeling and
the use of unique fittings and are subject to additional use conditions
mitigating flammability and toxicity as appropriate to the alternative.
---------------------------------------------------------------------------

    \155\ HFC-152a is listed as acceptable, subject to use
conditions, for new vehicles only at 40 CFR part 82 subpart G; final
rule published June 12, 2008 (73 FR 33304).
    \156\ CO2 is listed as acceptable, subject to use
conditions, for new vehicles only at 40 CFR part 82 subpart G; final
rule published June 6, 2012 (77 FR 33315).
---------------------------------------------------------------------------

    In section VI.B.3 of the proposed rule (81 FR at 22860-65; April
18, 2016), EPA provided information on the environmental and health
properties of HFO-1234yf and the available alternative in this end-use
in this action. In addition, EPA's risk assessments for HFO-1234yf and
a technical support document \157\ that provides the Federal Register
citations concerning data on the SNAP criteria (e.g., ODP, GWP, VOC,
toxicity, flammability) for acceptable alternatives in the relevant
end-uses may be found in the docket for this rulemaking (EPA-HQ-OAR-
2015-0663). In summary, HFO-1234yf has a GWP of one to four. HFO-1234yf
has a GWP similar to or lower than the GWP of other alternatives for
the HD vehicle types addressed in this action. For example, its GWP is
significantly lower than that of HFC-134a, the refrigerant most widely
used in these vehicles today, which has a GWP of 1,430. HFC-152a,\158\
and CO2\159\ have GWPs of 124 and one, respectively. The
refrigerant blends acceptable for use in MVAC systems for the HD
vehicle types addressed in this action have GWPs ranging from 1 to
1,510.
---------------------------------------------------------------------------

    \157\ EPA, 2016b. Tables of Alternatives for End-Uses Considered
in the Final Rule, Protection of Stratospheric Ozone: Listing
Modifications for Certain Substitutes under the Significant New
Alternatives Policy Program. September, 2016.
    \158\ HFC-152a is listed as acceptable, subject to use
conditions, for new vehicles only at 40 CFR part 82 subpart G; final
rule published June 12, 2008 (73 FR 33304).
    \159\ CO2 is listed as acceptable, subject to use
conditions, for new vehicles only at 40 CFR part 82 subpart G; final
rule published June 6, 2012 (77 FR 33315).

    Table 16--GWP, ODP, and VOC Status of HFO-1234yf Compared to Other Refrigerants in MVAC Systems of Newly
                       Manufactured MDPVs, HD Pickup Trucks, and Complete HD Vans \1\ \2\
----------------------------------------------------------------------------------------------------------------
          Refrigerants               GWP                  ODP                  VOC status        Listing status
----------------------------------------------------------------------------------------------------------------
HFO-1234yf.....................          1-4  0..........................  No................  Acceptable,
                                                                                subject to use
                                                                                conditions.
CO2, HFC-152a, HFC-134a........      1-1,430  0..........................  No................  Acceptable.
IKON A, R-416A, R-426A, SP34E..     30-1,510  0-Not public \3\...........  Yes \4\...........  Acceptable.
----------------------------------------------------------------------------------------------------------------
\1\ The table does not include not-in-kind technologies listed as acceptable for the stated end-use.
\2\ HCFC-22 and several blends containing HCFCs are also listed as acceptable but their use is severely
  restricted by the phasedown in HCFC production and consumption.
\3\ The ODP of one or more alternatives is not published here in order to avoid disclosing information that is
  claimed as confidential business information.
\4\ One or more constituents of the blend are VOC.

    HFO-1234yf does not deplete the ozone layer. Likewise, HFC-134a,
HFC-152a, CO2 and the HFC blends SP34E and R-426A do not
deplete the ozone layer; the HCFC blends have ODPs ranging from 0.012
to 0.056. HFO-1234yf, HFC-134a, HFC-152a, and CO2 are exempt
from the definition of VOC under CAA regulations (see 40 CFR 51.100(s))
addressing the development of SIPs to attain and maintain the NAAQS.
The HFC blends and some of the HCFC blends have one or more components
that are VOCs and that are not exempt from the definition in 40 CFR
51.100(s).
    A potential environmental impact of HFO-1234yf is its atmospheric
decomposition to trifluoroacetic acid (TFA, CF3COOH). TFA is
a strong acid that may accumulate on soil, on plants, and in aquatic
ecosystems over time and that may have the potential to adversely
impact plants, animals, and ecosystems.\160\ Simulations have found
that the amount of TFA in rainfall produced from a transition of all
mobile air conditioners in the continental United States to HFO-1234yf
has been estimated to be double or more the values observed in the
United States in 2009 from all sources, natural and artificial (i.e.,
HFC-134a) sources.\161\ In comparison, the amount of TFA produced from
HFO-1234yf is expected to be higher than that of other fluorinated
refrigerants in this end-use.
---------------------------------------------------------------------------

    \160\ Other fluorinated compounds also decompose into TFA,
including HFC-134a.
    \161\ Luecken et al., 2009. Ozone and TFA impacts in North
America from degradation of 2, 3, 3, 3-tetrafluoropropene (HFO-
1234yf), a potential greenhouse gas replacement. Environmental
Science & Technology 2009. The document is accessible at: http://www.researchgate.net/profile/Robert_Waterland/publication/40481734_Ozone_and_TFA_impacts_in_North_America_from_degradation_of_2333-Tetrafluoropropene_(HFO-
1234yf)_a_potential_greenhouse_gas_replacement/links/
00b7d514ca9595bf5e000000.pdf.
---------------------------------------------------------------------------

    In support of the 2011 listing decision for HFO-1234yf in LD
vehicles, EPA analyzed potential TFA concentrations from a full
transition to HFO-1234yf in all MVAC applications, not limited to LD
vehicles.162 163 164 165 166 The analysis

found a maximum projected concentration of TFA in rainwater of
approximately 1,700 ng/L. This maximum projected concentration
identified in EPA's analysis, 1700 ng/L,\167\ was roughly 34 percent
higher than that projected in a 2009 peer reviewed article.\168\ The
differences in projected TFA concentrations in water is a reflection of
EPA's reliance on higher emission estimates.\169\ Even when relying on
more conservative emission estimates, a concentration of 1700 ng/L
corresponds to roughly \1/600\th of the No-Observed-Adverse-Effect-
Level (NOAEL) for the most sensitive algae species, which is also well
below the NOAEL for the most sensitive aquatic animal species.\170\
---------------------------------------------------------------------------

    \162\ ICF, 2009a. Revised Final Draft Assessment of the
Potential Impacts of HFO-1234yf and the Associated Production of TFA
on Aquatic Communities and Local Air Quality.
    \163\ ICF, 2010a. Summary of HFO-1234yf Emissions Assumptions.
    \164\ ICF, 2010b. Summary of Updates to the Vintaging Model that
Impacted HFO-1234yf Emissions Estimates.
    \165\ ICF, 2010c. Revised Assessment of the Potential Impacts of
HFO-1234yf and the Associated Production of TFA on Aquatic
Communities, Soil and Plants, and Local Air Quality.
    \166\ ICF, 2010d. Sensitivity Analysis CMAQ results on projected
maximum TFA rainwater concentrations and maximum 8-hr ozone
concentrations.
    \167\ ICF, 2010d. Sensitivity Analysis CMAQ results on projected
maximum TFA rainwater concentrations and maximum 8-hr ozone
concentrations.
    \168\ Luecken et al., 2009. Ozone and TFA impacts in North
America from degradation of 2, 3, 3, 3-tetrafluoropropene (HFO-
1234yf), a potential greenhouse gas replacement. Environmental
Science & Technology 2009. The document is accessible at: http://www.researchgate.net/profile/Robert_Waterland/publication/40481734_Ozone_and_TFA_impacts_in_North_America_from_degradation_of_2333-Tetrafluoropropene_(HFO-
1234yf)_a_potential_greenhouse_gas_replacement/links/
00b7d514ca9595bf5e000000.pdf.
    \169\ ICF, 2010d. Sensitivity Analysis CMAQ results on projected
maximum TFA rainwater concentrations and maximum 8-hr ozone
concentrations.
    \170\ ICF, 2009a. Revised Final Draft Assessment of the
Potential Impacts of HFO-1234yf and the Associated Production of TFA
on Aquatic Communities and Local Air Quality.
---------------------------------------------------------------------------

    Taking into consideration the analysis conducted in support of the
2011 listing decision, which was based on conservative emissions
assumptions and a transition from HFC-134a to HFO-1234yf for all MVAC
systems (not limited to LD vehicles), and the research that has been
conducted since, EPA concludes that the use of HFO-1234yf in the HD
vehicle types addressed in this action will not pose a significant risk
to the environment from atmospheric decomposition to TFA.
    HFO-1234yf is a flammable refrigerant classified as A2L under
ASHRAE 34-2013. HFC-134a and CO2 are nonflammable
refrigerants, while HFC-152a is slightly more flammable than HFO-1234yf
with an ASHRAE classification of A2. The blends listed as acceptable
are not flammable.
    EPA compared worker exposures to a workplace exposure limit of 250
ppm \171\ over an 8-hour time-weighted average for long-term
occupational exposure to HFO-1234yf. For short-term occupational
exposure to HFO-1234yf, we compared worker exposure to an acute
exposure limit of 98,211 ppm, divided by a margin of exposure of 30,
for a value of 3,270 ppm over 30 minutes.172 173 Concerning
workplace exposure, we expect that professional technicians have proper
training and certification and have the proper equipment and knowledge
to minimize their risks due to exposure to refrigerant from an MVAC
system. Thus, worker exposure to HFO-1234yf is expected to be low. If
workers service MVAC systems using certified refrigerant recovery
equipment after receiving training and testing, exposure levels to HFO-
1234yf are estimated to be on the order of 4 to 8.5 ppm on an 8-hour
time-weighted average (as compared with a 250 ppm workplace exposure
limit \174\) and 122 ppm on a 30-minute average (as compared with a
short-term exposure level of 98,211 ppm divided by a margin of exposure
of 30, for a value of 3270 ppm over 30 minutes
175 176).177 178 We also analyzed exposure levels
during manufacture and final disposition at vehicle end-of-life, and
found that they would be no higher than 28 ppm on a 15-minute average
or 8.5 ppm on an 8-hour time-weighted average.\179\ The manufacture,
use, and disposal or recycling of HFO-1234yf MVAC systems are not
expected to present a toxicity risk to workers. Other alternatives such
as HFC-134a and HFC-152a also do not present a toxicity risk to workers
in the same scenarios; therefore, HFO-1234yf

poses the same or less risk than other alternatives.
---------------------------------------------------------------------------

    \171\ This was based on a NOAEL of 4000 ppm from the study, ``An
Inhalation Prenatal Developmental Toxicity Study of HFO-1234yf
(2,3,3,3-Tetrafluoropropene) in Rabbits,'' EPA-HQ-OAR-2008-0664-
0041. We used a factor of 1.9 to account for differences in blood
concentrations between animals and humans, and a margin of exposure
or collective uncertainty factor of 30. Uncertainty factors of 3
were assigned for animal to human extrapolation, and 10 for
variability within the human population. The long-term workplace
exposure limit was calculated as follows: 4000 ppm (animal exposure)
x 1.9 (ratio of estimated human exposure/animal exposure) x \1/3\
(UF for animal to human extrapolation) x \1/10\ (UF for variability
within the human population) exposure) = 250 ppm. This value was
compared against 8-hour average concentrations. See EPA-HQ-OAR-2008-
0664-0036 and EPA-HQ-OAR-2008-0664-0038.
    \172\ This was based on a NOAEL of 51,690 ppm from the study,
``Sub-acute (2-week) Inhalation Toxicity Study with HFO-1234yf in
rats,'' EPA-HQ-OAR-2008-0664-0020 through-0020.4, a factor of 1.9 to
account for differences in blood concentrations between animals and
humans and a margin of exposure or collective uncertainty factor of
30. Uncertainty factors of 3 were assigned for animal to human
extrapolation, and 10 for variability within the human population.
The short-term workplace exposure value was calculated as follows:
51,690 ppm (animal exposure) x 1.9 (ratio of estimated human
exposure/animal exposure) = 98,211 ppm This value was then divided
by the expected exposure in each scenario, and compared against the
target margin of exposure of 30. See EPA-HQ-OAR-2008-0664-0036 and
EPA-HQ-OAR-2008-0664-0038.
    \173\ For comparison, the SAE CRP used exposure limits of 500
ppm over 8 hours and 115,000 ppm over 30 minutes to evaluate risks
for these same time periods. These are based on the 8-hr Workplace
Environmental Exposure Limit (WEEL) for HFO-1234yf and for short-
term exposure, assuming a NOAEL of approximately 405,800 ppm from
the study, ``Acute (4-hour) inhalation toxicity study with HFO-
1234yf in rats.'' Note that EPA disagrees with the finding that the
acute inhalation toxicity study found a NOAEL. We consider this
study to show adverse effects at all levels because of the presence
of grey discoloration in the lungs of the test animals. In order to
ensure sufficient protection, EPA's risk assessment used a NOAEL
from a subacute study instead of a LOAEL from an acute study.
    \174\ This was based on a NOAEL of 4000 ppm from the study, ``An
Inhalation Prenatal Developmental Toxicity Study of HFO-1234yf
(2,3,3,3-Tetrafluoropropene) in Rabbits,'' EPA-HQ-OAR-2008-0664-
0041. We used a factor of 1.9 to account for differences in blood
concentrations between animals and humans, and a margin of exposure
or collective uncertainty factor of 30. Uncertainty factors of 3
were assigned for animal to human extrapolation, and 10 for
variability within the human population. The long-term workplace
exposure limit was calculated as follows: 4000 ppm (animal exposure)
x 1.9 (ratio of estimated human exposure/animal exposure) x \1/3\
(UF for animal to human extrapolation) x \1/10\ (UF for variability
within the human population) exposure) = 250 ppm. This value was
compared against 8-hour average concentrations. See EPA-HQ-OAR-2008-
0664-0036 and EPA-HQ-OAR-2008-0664-0038.
    \175\ This was based on a NOAEL of 51,690 ppm from the study,
``Sub-acute (2-week) Inhalation Toxicity Study with HFO-1234yf in
rats,'' EPA-HQ-OAR-2008-0664-0020 through-0020.4, a factor of 1.9 to
account for differences in blood concentrations between animals and
humans and a margin of exposure or collective uncertainty factor of
30. Uncertainty factors of 3 were assigned for animal to human
extrapolation, and 10 for variability within the human population.
The short-term workplace exposure value was calculated as follows:
51,690 ppm (animal exposure) x 1.9 (ratio of estimated human
exposure/animal exposure) = 98,211 ppm. This value was then divided
by the expected exposure in each scenario, and compared against the
target margin of exposure of 30. See EPA-HQ-OAR-2008-0664-0036 and
EPA-HQ-OAR-2008-0664-0038.
    \176\ For comparison, the SAE CRP used exposure limits of 500
ppm over 8 hours and 115,000 ppm over 30 minutes to evaluate risks
for these same time periods. These are based on the 8-hr Workplace
Environmental Exposure Limit (WEEL) for HFO-1234yf and for short-
term exposure, assuming a NOAEL of approximately 405,800 ppm from
the study, ``Acute (4-hour) inhalation toxicity study with HFO-
1234yf in rats.'' Note that EPA disagrees with the finding that the
acute inhalation toxicity study found a NOAEL. We consider this
study to show adverse effects at all levels because of the presence
of grey discoloration in the lungs of the test animals. In order to
ensure sufficient protection, EPA's risk assessment used a NOAEL
from a subacute study instead of a LOAEL from an acute study.
    \177\ EPA, 2009b. Risk Assessment: PMN 07-0601. Available at:
http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OAR-2008-0664-
0036.
    \178\ ICF International, 2009b. Risk Screen on Substitutes for
CFC-12 in Motor Vehicle Air Conditioning: Substitute: HFO-1234yf.
Available online at: http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OAR-2008-0664-0038.
    \179\ Ibid.
---------------------------------------------------------------------------

    As explained in section VI.B.3 of the proposed rule (81 FR at
22860-65; April 18, 2016), to evaluate environmental, flammability, and
toxicity risks resulting from the use of HFO-1234yf in new MDPVs, HD
pickup trucks, and complete HD vans, the Agency relied on EPA's
analysis conducted in support of the 2011 listing decision for HFO-
1234yf for LD vehicles. EPA was able to rely on the 2011 analysis of
HFO-1234yf in LD vehicles in support of this rule because the MVAC
systems, vehicle designs, and the potential for exposure for the HD
vehicle types for which EPA is listing HFO-1234yf as acceptable,
subject to use conditions, in this action are identical or very similar
to those of LD vehicles. In addition, we considered risk assessments
performed by OEMs and independent consultants on the use of HFO-1234yf
in LD vehicles through SAE Cooperative Research Programs (CRPs) and
found these were consistent with our analysis. Based on that analysis,
at proposal, EPA concluded HFO-1234yf did not pose a significantly
greater due to environmental effects, flammability or toxicity than the
other alternatives when used in accordance with use conditions
established as part of the listing decision. The refrigerants to which
HFO-1234yf was compared in the 2011 action for LD vehicles are the same
refrigerants available for use in the vehicle types included in this
action.
    Based on the consideration of all of SNAP criteria, EPA has
determined that HFO-1234yf does not pose significantly greater risk
than the other alternatives, when used in accordance with use
conditions, for use in newly manufactured MDPVs, HD pickup trucks, and
complete HD vans. Further information on these analyses and EPA's risk
assessments are available in the docket for this rulemaking (EPA-HQ-
OAR-2015-0663).
b. What are the final use conditions?
    All MVAC refrigerants listed as acceptable are subject to use
conditions requiring labeling and the use of unique fittings. EPA is
listing HFO-1234yf as acceptable, subject to use conditions, because
the use conditions are necessary to ensure that use of HFO-1234yf will
not have a significantly greater overall impact on human health and the
environment than other alternatives for use in MDPVs, HD pickup trucks,
and complete HD vans. EPA is requiring the same use conditions for HFO-
1234yf in these HD vehicle types as are required for the use of HFO-
1234yf in newly manufactured LD vehicles. Because of the similarities
in the MVAC systems used for these vehicles, these use conditions will
ensure use of HFO-1234yf in MDPVs, HD pickup trucks, and complete HD
vans does not pose significantly greater risk than use of other
alternatives.
    The first use condition requires that MVAC systems designed to use
HFO-1234yf must meet the requirements of SAE J639, ``Safety Standards
for Motor Vehicle Refrigerant Vapor Compression Systems.'' This
standard sets safety standards that include unique fittings; a warning
label indicating the refrigerant's identity and that it is a flammable
refrigerant; and requirements for engineering design strategies that
include a high-pressure compressor cutoff switch and pressure relief
devices. This use condition also requires that for connections with
refrigerant containers for use in professional servicing, use fittings
must be consistent with SAE J2844 (revised January 2013), which
specifies quick-connect fittings that are different from those for any
other refrigerant. The low-side service port and connections will have
an outside diameter of 14 mm (0.551 inches) and the high-side service
port will have an outside diameter of 17 mm (0.669 inches), both
accurate to within 2 mm. Under SAE J2844 (revised January 2013),
containers of HFO-1234yf for use in professional servicing of MVAC
systems must have a left-handed screw valve with a diameter of 0.5
inches and Acme (trapezoidal) thread with 16 threads per inch. The SAE
standards did not include and EPA did not receive a submission for
unique fittings for small containers of HFO-1234yf refrigerant prior to
the publication of the proposed rule.