refrigerant from air-conditioning or heat pump units must be viewed
probabilistically--that is, only a very small fraction of AC or heat
pump units would experience leaks at any given point in time, and only
a small fraction of these leaks would be sudden releases. The commenter
stated that there is no basis for assuming that every possible leak in
an R443A-based system would be sudden and complete, as opposed to slow
and diluted. Values of 0.1 to one percent are much more realistic than
100 percent full release.
    Response: With respect to EPA's assumptions for estimating total
emissions for its air quality analysis, EPA assumed 100 percent release
of refrigerant at disposal in most of the scenarios, to simulate a
situation where venting would not be prohibited. As discussed
previously, EPA considered scenarios where venting would be prohibited
and also considered emissions from leaks. However, based upon the
historical information EPA used in establishing the Vintaging Model and
on reviewer input of those data, we consider the commenter's estimated
probability of leaks to be low, particularly for residential split AC
and heat pump equipment and for older equipment, which would be more
likely to leak through extended lines. The study that was the basis for
the commenter's estimates was based upon monitoring of commercial AC
equipment in supermarkets of a type and age that was not described. If
the equipment in the study was chiller equipment, this leak rate would
be reasonable and close to the annual average leak rate EPA used in its
emissions analysis for chillers, but the leak rate would be low for
residential or light commercial AC and heat pump equipment,
particularly for split systems.
    With respect to EPA's leak assumptions in our risk screens for
purposes of assessing flammability and toxicity impacts, we first
conducted a worst-case analysis that assumed a release of 95 percent of
the refrigerant charge within one minute. This was an initial screen to
determine whether the refrigerant would ever potentially exceed the LFL
or relevant exposure limits. Since there were some potential
exceedances with the most conservative assumptions, EPA then considered
additional, less conservative assumptions concerning ventilation rates,
charge sizes, and stratification or complete mixing of release
refrigerant, and did not evaluate smaller leaks. EPA agrees with the
commenter that slow, small leaks are likely to be far more common than
large leaks. However, EPA must consider the possibility of a complete
release because that is a possible, if less frequent, situation.
    Comment: Whitmyre Research stated that EPA analyses incorrectly
assumed air-exchange rates far lower than those allowed by ASHRAE
standards incorporated in building codes (at least 0.35 ACH in typical
residential structures). Based on data from Pandian et al. (1998),\89\
the median residential air exchange rate in the United States (across
all regions, all seasons) is 0.5 ACH. Therefore, the presumed exposures
are unlikely and unrealistic for both the toxicity and flammability
scenarios presented in this rule.
---------------------------------------------------------------------------

    \89\ Pandian et al., 1998. ``Correcting Errors in the Nationwide
Data Base of Residential Air Exchange Rates.'' Journal of Exposure
Analysis and Environmental Epidemiology, Vol. 8, No. 4, 577-585.
---------------------------------------------------------------------------

    Response: We disagree that the air exchange rates used in the
scenarios are not representative and do not represent likely scenarios.
First, we note that the air-exchange value from ASHRAE is from a 2016
standard and applies only to newly constructed buildings; thus, it does
not apply to existing housing stock, which is the vast majority of what
is available. Second, both the value from ASHRAE and the median value
from Pandian et al. fall within the range of air exchange rates that
EPA analyzed of 0.11 to 0.67 ACH.
    Comment: Whitmyre Research and Whitmyre Equipment Corporation
claimed there is no need for concern about leakage because a safety
valve design option already exists (per the request of EPA) that will
greatly limit refrigerant loss during leak events.
    Response: A safety valve, such as the check valve suggested by the
commenter for R-443A, may reduce the size of leaks and thereby reduce
risk of using the refrigerant. However, the submitter did not provide
information on applying the check valve to equipment in this end-use.
It is not clear, based on the information provided for the check valve
in another end-use, that it would mitigate risk sufficiently to say R-
443A poses lower overall risk to human health and the environment. For
instance, if the check valve works as described, it could reduce the
amount of refrigerant leaked and potentially avoid exceedances of the
LFL or the acute exposure limit. However, it is not clear that this
check valve would be able to avoid slower leaks that over time
contribute substantially to VOC emissions and to adverse air quality
impacts, even if it works as designed. Further, EPA has not seen
sufficient information to be confident of the performance of the safety
valve.
iii. Flammability
    Comment: Whitmyre Research and Refrigerants, Naturally! stated that
EPA's discussion of flammability risk does not account for probability
and therefore greatly overstates any concern for use of R-443A in both
normal operation and maintenance/repair/disposal situations. Whitmyre
Research stated that in order for there to be a flammability risk,
there must be a co-occurrence of a leak event and a spark generation
event. Subsequently, the probabilities of fire for normal operation of
these devices, when charged with the specified amount of R-443A, and
during maintenance, repair, and disposal, are quite low as calculated
by the commenter in a fault tree analysis (FTA) included in the
submission for R-443A. Refrigerants, Naturally! commented that there
should be no differentiation between R-443A and other HCs in regards to
flammability.
    Response: EPA agrees that flammability risk for R-443A and
propylene would not be significantly different from the risks for other
HC refrigerants for the same uses. EPA's risk screen is intended to
look first at reasonable worst-case scenarios and then at more typical
scenarios, while remaining protective, and is not intended to discuss
probability. EPA did evaluate the probability of events presented by
the submitter in the FTA. As discussed in this section VI.A.4.c.i under
``Assumptions in EPA's Analyses,'' the study that was the basis for the
commenter's estimates was based upon monitoring of commercial AC
equipment in supermarkets of a type and age that was not described. If
the equipment in the study was chiller equipment, this leak rate would
be reasonable and close to the annual average leak rate EPA used in its
emissions analysis for chillers, but the leak rate would be low for
residential or light commercial AC and heat pump equipment,
particularly for split systems. Thus, the probabilities estimated by
the commenter likely

underestimate risks for residential and light commercial AC and heat
pumps. In addition to worst-case scenarios, more typical scenarios, and
FTAs, EPA also considered where there are industry standards or
controls in place that can mitigate flammability risks.
    Comment: UTC supported EPA's proposal to list both R-443A and
propylene as unacceptable in residential and light commercial AC and
heat pumps, cold storage warehouses, and centrifugal and positive
displacement chillers for commercial comfort AC. However, the commenter
believed that they also should be found unacceptable based on
flammability concerns. In particular, the commenter asserted that since
both propylene and R-443A are Class 3 flammable refrigerants, they
should be considered unacceptable.
    Response: EPA disagrees that flammability concerns should also
provide a basis for listing R-443A and propylene as unacceptable in all
the proposed end-uses. EPA previously listed two ASHRAE Class 3
refrigerants as acceptable, subject to use conditions, for use only in
new room air conditioners (i.e., propane and R-441A). For those
refrigerants, EPA established use conditions that limited charge size
and that would mitigate flammability risks. We note that the
flammability risks for R-443A and propylene are similar to those for
other Class A3 refrigerants.
    For equipment with larger charge sizes, such as some unitary split
AC systems and heat pumps or most centrifugal and positive displacement
chillers, the flammability risk is a greater concern than for equipment
with smaller sizes, such as self-contained room air conditioners.
However, by stating the flammability risk is greater for equipment with
larger charge sizes, EPA is not implying that such risks could never be
mitigated. ASHRAE, AHRI, and DOE are investing $5.2 million in research
with the goal of using the results to update industry standards,
subject to the ANSI consensus process, to address flammability risks.
Such updates to standards would address risks in a broader range of
equipment than the current UL standards.
iv. Toxicity and Exposure
    Comment: Whitmyre Research stated that the Agency had
``misconstrued the toxicity of propylene.'' The commenter stated that
propylene is widely recognized as having very low toxicity by
inhalation (e.g., narcosis occurs at 35-46 percent by volume). Whitmyre
Research stated that that the Agency's concern for the toxicity of
propylene is misplaced, because (1) the Agency's modeled exposures are
based on flawed methods and incorrect assumptions; (2) R-443A is only
partially made of propylene; (3) propylene is simply not toxic at the
modeled levels; and (4) the Agency used inappropriate toxicity
benchmarks. Specific assumptions in some of EPA's scenarios that the
commenter disagreed with included the length of time for the entire
refrigerant charge to release, the ventilation rates, and the
assumption of stratification of refrigerant (i.e., pooling near the
floor). The commenter also stated that the Agency must match the time-
frame of exposure to catastrophic releases of R-443A (minutes) in
establishing a toxicity benchmark.
    Response: Based on this comment, EPA reconsidered the available
toxicology data for propylene and agrees that it indicates lower
concern for acute exposure than indicated in our risk assessment for
the proposed rule. Concerning the commenter's complaint about the
methods and assumptions for modeled exposures, EPA's analysis looked at
a variety of scenarios. These scenarios considered ventilation rates
both above and below those suggested by the commenter and both
stratification of refrigerant and complete mixing of refrigerant within
the space. We note that with a higher ventilation rate than that
suggested by the commenter and with an assumption of no refrigerant
stratification, concentrations reached 9,680 ppm over 30 minutes from
release of a larger charge for a split system, exceeding both the
excursion limit of 1,500 ppm and an acute exposure limit of 6,900 ppm
over 30 minutes, analogous to the AEGL-1 for propane. EPA separately
evaluated the propylene fraction when comparing modeled concentrations
against the guideline for propylene, and thus, considered that it is
only part of R-443A's composition.
    We agree that the modeled exposure levels are below the level at
which toxicity has actually been observed. However, it is standard
practice to use more conservative values in evaluating toxicity risk
than the no observed adverse effect level (NOAEL) seen in studies to
account for uncertainty, such as variability within the general
population or differences between species. Concerning the toxicity
benchmark used by EPA--an excursion limit of three times the ACGIH
TLV--EPA agrees that there could be other, less conservative benchmarks
that could be used. We reviewed the available toxicity data for
propylene and also considered how the toxicity profile of propylene
differs from that of propane to determine what might be an appropriate,
less conservative benchmark. We concluded that there were not major
differences between the two HCs that warranted using a much lower acute
exposure limit for propylene than for propane.\90\ Therefore, we
reevaluated consumer exposure to propylene using an acute exposure
limit of 6,900 ppm over 30 minutes for propylene, analogous to the
AEGL-1 of 6,900 ppm for propane. In that revised evaluation, releases
of the propylene fraction of R-443A from smaller room air conditioners
could meet this acute exposure limit, but releases from split AC
systems and heat pumps with higher charges could exceed the acute
exposure limit. Thus, we still consider toxicity of propylene in R-443A
to potentially be of concern for residential and light commercial AC
and heat pump equipment with large charge sizes such as split AC
systems, but it is not a concern for room air conditioners with limited
charge sizes.
---------------------------------------------------------------------------

    \90\ Abt Associates, 2016. Review of propylene acute toxicity
for R-443A risk screen. Prepared for EPA. July 6, 2016.
---------------------------------------------------------------------------

    Comment: Whitmyre Research stated that there is no asphyxiation
risk at the Immediately Dangerous to Life and Health (IDLH) limit; it
is not an indicator of asphyxiation risk.
    Response: EPA agrees that the IDHL is not an indicator of
asphyxiation risk; however, EPA used a minimum oxygen concentration of
12 percent in assessing asphyxiation risk and did not use the IDLH.
    Comment: Whitmyre Research stated that the TLV of 500 ppm for
propylene that was established by ACGIH is a chronic exposure limit to
be applied only to repeated exposures at least 40 hours per week over
an occupational lifetime. ACGIH based the TLV of 500 ppm for propylene
on nasal irritation effects occurring in treated animals exposed 6
hours per day, five days per week, for 103 weeks (2 years). No such
nasal effects were observed in rats or mice exposed acutely (i.e.,
single inhalation dose) or when exposed to up to 10,000 ppm propylene
for 6 hours per day, 5 days per week for 14 days (ACGIH 2006).
    Response: EPA agrees that the ACGIH's TLV for propylene, like other
TLVs, is intended to be a chronic exposure limit and is based on longer
term exposure. However, the ACGIH also recommends that short term
excursions over a TLV should be no more than three times the TLV, on a
regular basis, and in no case should exceed five times the TLV. The
commenter has not suggested a specific

value that they propose EPA should use instead to assess risks of
short-term exposure.
5. Change of Listing Status for Certain HFC Refrigerants for New
Centrifugal Chillers and for New Positive Displacement Chillers
a. Background
i. What are the affected end-uses?
    In the proposed rule, EPA described two chiller end-uses,
specifically centrifugal chillers and positive displacement chillers.
We draw attention to the fact that, as discussed there, in some cases
the same refrigerant is used in both end-uses. Of note is the fact that
HFC-134a is used for some centrifugal chillers, namely ``high-
pressure'' centrifugal chillers, as well as in some positive
displacement chillers, such as screw chillers. In addition, as
discussed below, at least two alternatives--HFO-1234ze(E) and R-513A--
have been used in both types of chillers. EPA received many comments
concerning chillers that did not specifically say whether the comment
was referencing centrifugal chillers, positive displacement chillers,
or both. Therefore, in today's rule, we are addressing both end-uses in
this section.
    Centrifugal chillers are equipment that utilize a centrifugal
compressor in a vapor-compression refrigeration cycle. They are
typically used for commercial comfort AC although other uses do exist.
Centrifugal chillers tend to be used in larger buildings, such as
office buildings, hotels, arenas, convention halls, airport terminals,
and other buildings.
    For commercial comfort and some other applications, centrifugal
chillers typically cool water that is then pumped to fan coil units or
other air handlers to cool the air that is supplied to the occupied
spaces transferring the heat to the water. The heat absorbed by the
water can then be used for heating purposes, and/or can be transferred
directly to the air (``air-cooled''), to a cooling tower or body of
water (``water-cooled'') or through evaporative coolers (``evaporative-
cooled''). See section VI.A.4.a.i of the proposed rule for additional
information on the centrifugal chiller end-use (81 FR 22841-42; April
18, 2016).
    Positive displacement chillers are vapor compression cycle chillers
that utilize positive displacement compressors, such as reciprocating,
screw, scroll or rotary types. Positive displacement chillers are
applied in similar situations as centrifugal chillers, primarily for
commercial comfort AC, except that positive displacement chillers tend
to be used for smaller capacity needs such as in mid- and low-rise
buildings. See section VI.A.4.b.i of the proposed rule for additional
information on the positive displacement chiller end-use (81 FR 22841-
42; April 18, 2016).
ii. What other types of equipment are used for similar applications but
are not covered by this section of the rule?
    Other equipment including packaged rooftop units and split system
air conditioners, both of which fall under the SNAP end-use
``residential and light commercial air conditioning,'' can also be used
for commercial comfort AC, typically for even smaller capacity needs
than positive displacement chillers. These equipment types are not
centrifugal or positive displacement chillers and hence are not covered
under this section of the rule. EPA responds to comments regarding the
scope of chillers--both centrifugal and positive displacement--end-uses
in section VI.A.5.c.i.
iii. What refrigerants are used in centrifugal and positive
displacement chillers?
    EPA discussed historical and recent use of refrigerants in
centrifugal chillers in section VI.A.4.a.i.(c) of the proposed rule (81
FR 22842; April 18, 2016). Since then, EPA has become aware of numerous
additional demonstrations, availability, and announcements regarding
alternative refrigerants for use in centrifugal chillers. For example,
Honeywell stated in their comments that ``[s]everal manufacturers
currently offer high-efficiency chillers, air-cooled (outdoor) and
water-cooled (indoor), using HFO-1234ze(E) in sizes ranging from tens
of tons to hundreds of tons'' and listed some examples, including some
centrifugal chillers. Multiple companies have introduced chillers using
HFO-1234ze(E), including Star Refrigeration,\91\ Klima-Therm,\92\
Airedale,\93\ Geoclima,\94\ Mitsubishi Heavy Industries,\95\ Smardt
Chiller Group,\96\ RC Group,\97\ Engie Refrigeration,\98\ and
Climaveneta.\99\
---------------------------------------------------------------------------

    \91\ Star Refrigeration, 2012. ``Star's Three-Way Development
Test for R-1234ze(E).'' July 2012. This document is accessible at
http://www.star-ref.co.uk/star/images/stories/pdf/Case%20Study%20No%2082%20-%20Refrigerant%20R-1234ze.pdf.
    \92\ RAC, 2012. ``Klima-Therm discusses world's first HFO
chiller for Waitrose.'' January 10, 2012. This document is
accessible online at http://www.racplus.com/features/klima-therm-discusses-worlds-first-hfo-chiller-for-waitrose/8624689.article.
    \93\ The NEWS, 2014. ``Airedale Chiller with Low-GWP HFO
Refrigerant to Cool New John Lewis Store.'' June 9, 2014. This
document is accessible at http://www.achrnews.com/articles/126828-airedale-chiller-with-low-gwp-hfo-refrigerant-to-cool-new-john-lewis-store.
    \94\ Geoclima, 2014. Geoclima Brochure. This document is
accessible at http://www.benndorf-hildebrand.eu/sites/default/files/fabrikate/pdf/geoclima_broschure.pdf.
    \95\ Mitsubishi, 2012. ``Deployment to New Series of `eco Turbo
chiller ETI series.' '' This document is accessible at http://www.mhi.co.jp/technology/review/pdf/491/491058.pdf.
    \96\ SMARDT, 2016. ``Revolutionary Energy Savings for the Built
Environment'', ``Trendsetting Technologies for Centrifugal
Chillers.'' These documents are available at http://climatecontrolme.com/2013/12/trendsetting-technologies-for-centrifugal-chillers/and http://www.smardt.com/docs/SMARDT%20BROCHURE%20ENGLISH%20JAN%202016.pdf.
    \97\ RC Group, 2016. ``Unico Turbo Air Cooled Liquid Chiller.''
This document is accessible at http://www.rcgroup.it/EN/Prodotti/?idP=1563.
    \98\ Engie Refrigeration, 2016. ``Quantum: Series and features
of the energy-efficient chiller series.'' This document is
accessible at https://www.engie-refrigeration.de/export/sites/cofelyrefrigeration/content/documents/ENG/Produkte/Quantum/ENG_Quantum_Folder.pdf.
    \99\ Climaveneta, 2015. ``Against Global Warming with the NEW
TECS2 HFO Chillers.'' January 12, 2015. This document is accessible
at http://www.climaveneta.com/EN/Media/Press-Releases/112.html.
---------------------------------------------------------------------------

    Centrifugal chillers using the alternative R-1233zd(E) have also
been offered, from at least three manufacturers: Trane (a brand of
Ingersoll Rand),\100\ Carrier (a brand of UTC) \101\ and Mitsubishi
Heavy Industries.\102\ Ingersoll Rand confirmed in their comment that
they have R-1233zd(E) centrifugal chillers available now and further
stated that they will have centrifugal chillers under their Trane brand
using R-514A available in 2017.
---------------------------------------------------------------------------

    \100\ Trane, 2016. ``Trane Announces Significant Centrifugal
Chiller Line Expansion and Services for the United States and
Canada.'' June 15, 2016. This document is accessible at http://www.trane.com/commercial/north-america/us/en/about-us/newsroom/press-releases/centrifugal-chiller-line-expansion.html.
    \101\ Carrier, 2016. ``Carrier China Showcases latest
Innovations at China Refrigeration Expo.'' April 7, 2016. This
document is accessible at http://www.carrier.com/carrier/en/us/news/news-article/carrier_china_showcases_latest_innovations_at_china_refrigeration_expo.aspx.
    \102\ MHI, 2015. ``MHI Develops `ETI-Z Series' of Next-
generation Centrifugal Chiller--Adopt New Non-ozone-depleting
Refrigeration to Minimize Greenhouse Gas Emissions.'' June 10, 2015.
This document is accessible at www.mhi-global.com/news/story/1506101900.html.
---------------------------------------------------------------------------

    A fourth alternative that is already available for some centrifugal
chillers is R-513A. For instance, Johnson Controls announced this year
that the centrifugal (and screw) chillers they offer, originally
designed for HFC-134a, are compatible with R-513A.\103\
---------------------------------------------------------------------------

    \103\ Johnson Controls, 2016. ``Johnson Controls Advances
Environmental Sustainability with Chiller Platforms Compatible with
Low GWP Refrigerants.'' January 20, 2016. http://www.johnsoncontrols.com/media-center/news/press-releases/2016/01/20/advanced-environmental-sustainability-with-chiller-platforms-compatible-with-low-gwp-refrigerants.
---------------------------------------------------------------------------

    EPA discussed historical and recent use of refrigerants in positive

displacement chillers in section VI.A.4.b.i.(c) of the proposed rule
(81 FR 22846; April 18, 2016), noting for instance that Trane
introduced a series of positive displacement chillers offered with R-
513A and that UTC had installed a screw chiller using HFO-1234ze(E).
    Since then, EPA has become aware of additional demonstrations,
availability and announcements regarding alternative refrigerants for
use in positive displacement chillers. For example, in their comments,
Ingersoll Rand noted their commitment to transition its entire chiller
portfolio, including positive displacement screw and scroll chillers,
before the end of 2018. They separately announced their intention to
use R-452B in ``small chillers'' as well as other products.\104\
Johnson Controls also announced that they were offering multiple
positive displacement chillers, covering their entire line of screw
chillers, with the choice of R-513A refrigerant.\105\ It was reported
that UTC chose HFO-1234ze(E) for their global line of screw
chillers.\106\ Blue Box has designed its Kappa Rev range of screw
chillers specifically for HFO-1234ze(E).\107\ This refrigerant is also
available in positive displacement chillers from Geoclima.\108\
---------------------------------------------------------------------------

    \104\ Ingersoll Rand, undated. ``Ingersoll Rand Innovates HVAC
Portfolio Using
    Next Generation, Low Global Warming Refrigerant, R-452B.'' This
document is accessible at http://company.ingersollrand.com/content/dam/ir-corp/documents/pdf/2016-DR55-Update-Release-FINAL.pdf.
    \105\ Johnson Controls, 2016. ``Johnson Controls Advances
Environmental Sustainability with Chiller Platforms Compatible with
Low GWP Refrigerants.'' January 20, 2016. This document is
accessible at http://www.johnsoncontrols.com/media-center/news/press-releases/2016/01/20/advanced-environmental-sustainability-with-chiller-platforms-compatible-with-low-gwp-refrigerants.
    \106\ RAC, 2016. ``Carrier opts for HFO 1234ze refrigerants for
global chiller range.'' February 26, 2016. This document is
accessible at http://www.racplus.com/news/carrier-opts-for-hfo-1234ze-refrigerants-for-global-chiller-range/10003440.article?blocktitle=News&contentID=15773.
    \107\ Cooling Post, 2015. ``Blue Box offers R1234ze chiller
option.'' April 29, 2015. This document is accessible at http://www.coolingpost.com/world-news/blue-box-offers-r1234ze-chiller-option/.
    \108\ Geoclima, 2014. Geoclima Brochure. This document is
accessible at http://www.benndorf-hildebrand.eu/sites/default/files/fabrikate/pdf/geoclima_broschure.pdf.
---------------------------------------------------------------------------

b. What is EPA's final decision?
    For new centrifugal chillers, EPA proposed to change the status as
of January 1, 2024, of the following refrigerants from acceptable to
unacceptable: FOR12A, FOR12B, HFC-134a, HFC-227ea, HFC-236fa, HFC-
245fa, R-125/134a/600a (28.1/70/1.9), R-125/290/134a/600a (55.0/1.0/
42.5/1.5), R-404A, R-407C, R-410A, R-410B, R-417A, R-421A, R-422B, R-
422C, R-422D, R-423A, R-424A, R-434A, R-438A, R-507A, RS-44 (2003
composition), and THR-03. We also proposed narrowed use limits for HFC-
134a and R-404A for certain centrifugal chillers. In this action, we
are finalizing the status changes and narrowed use limits that we
proposed with no changes. The change of status determinations for new
centrifugal chillers are summarized in Table 5.

    Table 5--Change of Status Decisions for New Centrifugal Chillers
------------------------------------------------------------------------
           End-use                 Substitutes         Listing status
------------------------------------------------------------------------
Centrifugal Chillers (new     FOR12A, FOR12B, HFC-  Unacceptable as of
 only).                        134a, HFC-227ea,      January 1, 2024,
                               HFC-236fa, HFC-       except where
                               245fa, R-125/134a/    allowed under a
                               600a (28.1/70/1.9),   narrowed use limit.
                               R-125/290/134a/600a
                               (55.0/1.0/42.5/
                               1.5), R-404A, R-
                               407C, R-410A, R-
                               410B, R-417A, R-
                               421A, R-422B, R-
                               422C, R-422D, R-
                               423A, R-424A, R-
                               434A, R-438A, R-
                               507A, RS-44 (2003
                               composition), and
                               THR-03.
Centrifugal Chillers (new     HFC-134a............  Acceptable, subject
 only).                                              to narrowed use
                                                     limits, for
                                                     military marine
                                                     vessels, as of
                                                     January 1, 2024.
Centrifugal Chillers (new     HFC-134a and R-404A.  Acceptable, subject
 only).                                              to narrowed use
                                                     limits, for human-
                                                     rated spacecraft
                                                     and related support
                                                     equipment, as of
                                                     January 1, 2024.
------------------------------------------------------------------------

    For new positive displacement chillers, EPA proposed to change as
of January 1, 2024 the status of the following refrigerants from
acceptable to unacceptable: FOR12A, FOR12B, HFC-134a, HFC-227ea, KDD6,
R-125/134a/600a (28.1/70/1.9), R-125/290/134a/600a (55.0/1.0/42.5/1.5),
R-404A, R-407C, R-410A, R-410B, R-417A, R-421A, R-422B, R-422C, R-422D,
R-424A, R-434A, R-437A, R-438A, R-507A, RS-44 (2003 composition),
SP34E, and THR-03. We also proposed narrowed use limits for HFC-134a
and R-404A for certain positive displacement chillers. In this action,
we are finalizing the status changes and narrowed use limits that we
proposed with no changes. The change of status determinations for new
positive displacement chillers are summarized in Table 6.

    Table 6--Change of Status Decisions for New Positive Displacement
                                Chillers
------------------------------------------------------------------------
           End-use                 Substitutes         Listing status
------------------------------------------------------------------------
Positive Displacement         FOR12A, FOR12B, HFC-  Unacceptable as of
 Chillers (new only).          134a, HFC-227ea,      January 1, 2024,
                               KDD6, R-125/134a/     except where
                               600a (28.1/70/1.9),   allowed under a
                               R-125/290/134a/600a   narrowed use limit.
                               (55.0/1.0/42.5/
                               1.5), R-404A, R-
                               407C, R-410A, R-
                               410B, R-417A, R-
                               421A, R-422B, R-
                               422C, R-422D, R-
                               424A, R-434A, R-
                               437A, R-438A, R-
                               507A, RS-44 (2003
                               composition),
                               SP34E, and THR-03.
Positive Displacement         HFC-134a............  Acceptable, subject
 Chillers (new only).                                to narrowed use
                                                     limits, for
                                                     military marine
                                                     vessels, as of
                                                     January 1, 2024.
Positive Displacement         HFC-134a and R-404A.  Acceptable, subject
 Chillers (new only).                                to narrowed use
                                                     limits, for human-
                                                     rated spacecraft
                                                     and related support
                                                     equipment, as of
                                                     January 1, 2024.
------------------------------------------------------------------------

i. How do these unacceptable refrigerants compare to other refrigerants
for these end-uses with respect to SNAP criteria?
    Other refrigerants for new centrifugal chillers not subject to this
action are HFO-1234ze(E), HFO-1336mzz(Z), IKON A, IKON B, R-450A, R-
513A, R-514A,\109\ R-717 (ammonia), R-744 (carbon dioxide), THR-02, and
trans-1-chloro-3,3,3-trifluoroprop-1-ene.\110\ In the proposed rule and
SNAP Acceptability Determination 31, EPA provided information on the
environmental and health risks presented by the alternatives that are
being found unacceptable compared with alternatives listed as
acceptable (81 FR 22842, April 18, 2016; and 81 FR 32242-45, May 23,
2016). In addition, a technical support document \111\ 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
centrifugal chillers may be found in the docket for this rulemaking
(EPA-HQ-OAR-2015-0663).
---------------------------------------------------------------------------

    \109\ In SNAP Determination 31 (81 FR 32241; May 23, 2016), EPA
found acceptable a blend of 74.7 percent by weight HFO-1336mzz(Z)
and 25.3 percent by weight trans-1,2-dichloroethylene. The Standing
Standard Project Committee updating ASHRAE Standard 34-2013 has
proposed assigning this blend a designation of R-514A, which is how
we refer to it throughout section VI.A.5 of this rule.
    \110\ ASHRAE Standard 34-2013 designates this chemical as R-
1233zd(E), which is how we refer to it throughout section VI.A.5 of
this rule.
    \111\ 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.
---------------------------------------------------------------------------

    For new centrifugal chillers, the refrigerants we are listing as
unacceptable have an insignificant ODP. Acceptable refrigerants HFO-
1234ze(E), HFO-1336mzz(Z), IKON A, IKON B, R-1233zd(E), R-450A, R-513A,
R-514A, R-717 (ammonia), R-744 (carbon dioxide), and THR-02 also have
an insignificant ODP. The alternative refrigerant R-1233zd(E) has an
ODP of 0.00024 to 0.00034.112 113 Estimates of this
compound's potential to deplete the ozone layer indicate that even with
worst-case estimates of emissions, which assume that this compound
would substitute for all compounds it could replace, the impact on
global atmospheric ozone abundance would be statistically
insignificant.\114\ R-514A has an ODP of approximately 0.00006, lower
than that of R-1233zd(E) and comparable to HFC-134a's calculated ODP of
less than 0.000015,\115\ which has generally been described as zero by
EPA and in common practice. Thus, the acceptable alternatives have ODPs
lower than or of the same practical effect to the ODPs of the
alternatives which EPA is listing as unacceptable, and lower than the
ODPs of ODS historically used in this end-use.
---------------------------------------------------------------------------

    \112\ Wang D., Olsen S., Wuebbles D. 2011. ``Preliminary Report:
Analyses of tCFP's Potential Impact on Atmospheric Ozone.''
Department of Atmospheric Sciences. University of Illinois, Urbana,
IL. September 26, 2011.
    \113\ Patten and Wuebbles, 2010. ``Atmospheric Lifetimes and
Ozone Depletion Potentials of trans-1-chloro-3,3,3-
trichloropropylene and trans-1,2-dichloroethylene in a three-
dimensional model.'' Atmos. Chem. Phys., 10, 10867-10874, 2010.
    \114\ Wang D., Olsen S., Wuebbles D. 2011. ``Preliminary Report:
Analyses of tCFP's Potential Impact on Atmospheric Ozone.''
Department of Atmospheric Sciences. University of Illinois, Urbana,
IL. September 26, 2011.
    \115\ The ODP of HFC-134a was estimated to be less than 1.5 x
10-5 using a theoretical 2-dimensional model.
Ravishankara, A. R., A. A. Turnipseed, N. R. Jensen, S. Barone, M.
Mills, C. J. Howard, and S. Solomon. 1994. Do hydrofluorocarbons
destroy stratospheric ozone? Science 263: 71-75. Available online at
http://www.ciesin.org/docs/011-552/011-552.html.
---------------------------------------------------------------------------

    The refrigerants we are listing as unacceptable through this action
have GWPs ranging from about 920 to 9,810. As shown in Table 7,
alternatives acceptable for this end-use not subject to this action
have GWPs ranging from zero to 630.

                                    Table 7--GWP, ODP, and VOC Status of Refrigerants in New Centrifugal Chillers 1 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
             Refrigerants                     GWP                      ODP                            VOC                       Listing status
--------------------------------------------------------------------------------------------------------------------------------------------------------
HFO-1234ze(E), R-1233zd(E), R-450A, R-           0-630  0-0.00034........................  No.......................  Acceptable.
 513A, R-717, R-744.
HFO-1336mzz(Z), IKON A, IKON B, R-               7-560  0--Not public \3\................  Yes \4\..................  Acceptable.
 514A, THR-02.
HFC-134a, HFC-245fa...................     1,030-1,430  0................................  No.......................  Unacceptable.
FOR12A, FOR12B, THR-03................       920-1,220  Not public \3\...................  Yes \4\..................  Unacceptable.
R-407C, R-410A, R-410B, R-421A, R-         1,770-3,220  0................................  No.......................  Unacceptable.
 423A, HFC-227ea.
R-125/134a/600a (28.1/70/1.9), R-125/      1,985-3,250  0................................  Yes \4\..................  Unacceptable.
 290/134a/600a (55/1/42.5/1.5), R-
 417A, R-422B, R-422C, R-422D, R-424A,
 R-434A. R-438A, RS-44 (2003
 composition).
HFC-236fa, R-404A, R-507A.............     3,920-9,810  0................................  No.......................  Unacceptable.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The table does not include not-in-kind technologies listed as acceptable for the stated end-use.
\2\ HCFC-22, HCFC-123, HCFC-124, 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.

    One of the refrigerant blends not subject to this action (THR-02),
as well as several of the substitutes for which we are changing the
listing from acceptable to unacceptable, include small amounts of R-290
(propane), R-600 (n-butane), 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.\116\ HFO-1336mzz(Z) and
trans-1,2-dichloroethylene (constituents of R-514A) are considered
VOCs; the producer has petitioned EPA to exempt HFO-1336mzz(Z) from the
definition of VOC. 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.
---------------------------------------------------------------------------

    \116\ 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 for which we are
changing the listing from acceptable to unacceptable for this end-use.

    With the exceptions of HFO-1234ze(E) and R-717, all other
refrigerants listed as acceptable and those we are listing as
unacceptable, are not flammable. HFO-1234ze(E) is nonflammable at
standard temperature and pressure using the standard test method ASTM
E681; however, at higher temperatures it is mildly flammable. It is
classified as a Class 2L (mild flammability, low burning velocity)
refrigerant under the standard ASHRAE 34 (2013). Our assessment and
listing decision (77 FR 47768; August 10, 2012) found that the overall
risk, including the risk due to this mild flammability at elevated
temperature, is not significantly greater than for other refrigerants
or for the refrigerants we are listing as unacceptable.
    The toxicity of the refrigerants we are listing as unacceptable is
comparable to that of other alternatives that are acceptable in this
end-use, with the exception of R-717 and R-514A. R-717 is of a higher
toxicity than the other acceptable refrigerants and is classified as a
B refrigerant under ASHRAE 34 (2013). See section VI.A.4.a.iii.(b) of
the proposed rule (81 FR 22843; April 18, 2016) for a discussion on the
long history of use of R-717 and our original decision finding it
acceptable in new centrifugal chillers. The use of R-717, also known as
ammonia, and the risks it might present are controlled through industry
standards, code requirements and other regulations. In the original
SNAP rule, EPA noted ``[a]mmonia [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). In that rule, we found R-717 acceptable for use in centrifugal
chillers, 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 the adherence to ASHRAE
Standard 15 and the International Institute of Ammonia Refrigeration
(IIAR) Standard 2,\117\ which are utilized by local authorities when
setting their own building and safety requirements.
---------------------------------------------------------------------------

    \117\ ANSI/International Institute of Ammonia Refrigeration
(IIAR) Standard 2-2008 (Addendum B)--American National Standard for
Equipment, Design, & Installation of Closed Circuit Ammonia
Mechanical Refrigerating Systems.
---------------------------------------------------------------------------

    R-514A is designed for use in low-pressure centrifugal chillers and
has the same toxicity rating as HCFC-123, which has and continues to be
used safely in such chillers. Because these refrigerants operate in
low-pressure chillers only, any leaks are more likely to cause air to
enter the chiller, rather than refrigerant to escape. Exposure is
further reduced by requirements set forth in ASHRAE Standard 15, which
is often cited in building codes. Specifically, Occupant Exposure
Limits and Refrigerant Concentration Limits for B1 refrigerants--
specified in ASHRAE Standard 34-2013 and mandated by ASHRAE Standard 15
and building codes--are lower than for A1 refrigerants, and these
limits must be observed in chiller operations. EPA's risk screen \118\
found that for a typical-size chiller using R-514A, even under
conservative assumptions, the estimated 15-minute time-weighted average
exposure would be well below (less than 12 percent of) the
corresponding limit. The other acceptable alternatives listed
previously that are included in ASHRAE 34 (2013) are classified as A
(lower toxicity) refrigerants. For further information, including EPA's
risk screens and risk assessments as well as information from the
submitters of the substitutes, see docket EPA-HQ-OAR-2015-0663.
---------------------------------------------------------------------------

    \118\ ICF, 2016m. Risk Screen on Substitutes in Chillers
Substitute: HFO-1336mzz(Z)/trans-1,2-dichloroethylene blend (74.7/
25.3) (OpteonTM XP30).
---------------------------------------------------------------------------

    In summary, for new centrifugal chillers, 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, HFC-227ea, KDD6, R-125/134a/
600a (28.1/70/1.9), R-125/290/134a/600a (55.0/1.0/42.5/1.5), R-404A, R-
407C, R-410A, R-410B, R-417A, R-421A, R-422B, R-422C, R-422D, R-424A,
R-434A, R-437A, R-438A, R-507A, RS-44 (2003 composition), SP34E, and
THR-03.
    For new positive displacement chillers, other alternatives that are
listed as acceptable and not subject to this action pose lower overall
risk to human health and the environment than the refrigerants we are
listing as unacceptable. Acceptable refrigerants for new positive
displacement chillers include: HFO-1234ze(E), HFO-1336mzz(Z), IKON B,
R-450A, R-513A, R-514A, R-717, R-744, and THR-02. In the proposed rule
and SNAP Acceptability Determination 31, EPA provided information on
the environmental and health risks presented by the alternatives that
are being found unacceptable compared with other available alternatives
listed as acceptable (81 FR 22846; April 18, 2016 and 81 FR 32242-
32245; May 23, 2016). In addition, a technical support document \119\
that provides the Federal Register citations of actions in which we
provide information on the SNAP criteria (e.g., ODP, GWP, VOC,
toxicity, flammability) for acceptable alternatives for new positive
displacement chillers, as well as those we are finding unacceptable,
may be found in the docket for this rulemaking (EPA-HQ-OAR-2015-0663).
---------------------------------------------------------------------------

    \119\ 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.
---------------------------------------------------------------------------

    For new positive displacement chillers, the refrigerants that we
are listing as unacceptable have insignificant ODPs and have GWPs
ranging from about 920 to 3,990. As shown in Table 8, other
alternatives that we are not listing as unacceptable in this end-use
have GWPs ranging from zero to 630.

         Table 8--GWP, ODP, and VOC Status of Refrigerants in New Positive Displacement Chillers \1\ \2\
----------------------------------------------------------------------------------------------------------------
         Refrigerants                 GWP                   ODP                    VOC           Listing status
----------------------------------------------------------------------------------------------------------------
HFO-1234ze(E), R-450A, R-513A,           0-630  0.........................  No...............  Acceptable.
 R-717, R-744.
HFO-1336mzz(Z), IKON B, R-               7-560  0--Not public \3\.........  Yes \4\..........  Acceptable.
 514A, THR-02.
HFC-134a......................           1,430  0.........................  No...............  Unacceptable.
FOR12A, FOR12B, SP34E, THR-03.       920-1,410  0--Not public \3\.........  Yes\4\...........  Unacceptable.
HFC-227ea, R-407C, R-410A, R-      1,770-3,220  0.........................  No...............  Unacceptable.
 410B, R-421A.

KDD6, R-125/134a/600a (28.1/70/    1,810-3,250  0.........................  Yes \4\..........  Unacceptable.
 1.9), R-125/290/134a/600a (55/
 1/42.5/1.5), R-417A, R-422B,
 R-422C, R-422D, R-424A, R-
 434A, R-437A, R-438A, RS-44
 (2003 composition).
R-404A, R-507A................     3,920-3,990  0.........................  No...............  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.

    One of the refrigerant blends not subject to this action (THR-02),
as well as several of the substitutes for which we are changing the
listing from acceptable to unacceptable, include small amounts of R-290
(propane), R-600 (butane), 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.\120\ HFO-1336mzz(Z) and
trans-1,2-dichloroethylene (constituents of R-514A) are considered
VOCs; the producer has petitioned EPA to exclude HFO-1336mzz(Z) from
the definition of VOC. In the actions where EPA listed these
refrigerants as acceptable, EPA concluded that none of the refrigerants
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.
---------------------------------------------------------------------------

    \120\ 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 HFO-1234ze(E) and R-717, all other
refrigerants that have been listed as acceptable, including those for
which we are now changing the status to unacceptable, are not
flammable. HFO-1234ze(E) is nonflammable at standard temperature and
pressure using the standard test method ASTM E681; however, at higher
temperatures it is mildly flammable. It is classified as a Class 2L
(mild flammability, low burning velocity) refrigerant under the
standard ASHRAE 34 (2013). Our assessment and listing decision (77 FR
47768; August 10, 2012) found that the overall risk, including the risk
due to this mild flammability at elevated temperature, is not
significantly greater than for other refrigerants or for the
refrigerants we are listing as unacceptable.
    R-717 (ammonia) is mildly flammable with a low flame speed; it is
classified as a 2L refrigerant under ASHRAE 34 (2013). R-717 has a long
history of use as a refrigerant in positive displacement chillers,
especially in water-cooled screw chillers, and other applications. In
our evaluation finding R-717 acceptable in this end-use, EPA noted
``[a]mmonia [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. Ammonia [R-717] may be used safely if existing OSHA and ASHRAE
standards are followed'' (61 FR 47015).
    With the exception of R-717, the toxicity of the refrigerants we
are listing as unacceptable is comparable to that of other alternatives
that are acceptable in this end-use. R-717, a refrigerant we are not
listing as unacceptable, is of a higher toxicity than some other
refrigerants and is classified as a B refrigerant under ASHRAE 34
(2013). See section VI.A.4.b.iii.(b) of the proposed rule (81 FR 22847;
April 18, 2016) for a discussion on the long history of use of R-717
and our original decision finding it acceptable in new positive
displacement chillers. However, as we provided in listing it as
acceptable, if used consistent with OSHA regulations, as well as
standard refrigeration practices, such as the adherence to ASHRAE
Standard 15 and the International Institute of Ammonia Refrigeration
(IIAR) Standard 2, which are utilized by local authorities when setting
their own building and safety requirements, it does not pose
significantly greater risk than other available refrigerants in this
end-use. For further information, including EPA's risk screens and risk
assessments as well as information from the submitters of the
substitutes, see docket EPA-HQ-OAR-2015-0663.
    In summary, for positive displacement chillers, 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, HFC-227ea, KDD6, R-125/134a/
600a (28.1/70/1.9), R-125/290/134a/600a (55.0/1.0/42.5/1.5), R-404A, R-
407C, R-410A, R-410B, R-417A, R-421A, R-422B, R-422C, R-422D, R-424A,
R-434A, R-437A, R-438A, R-507A, RS-44 (2003 composition), SP34E, and
THR-03.
ii. Narrowed Use Limits for Military Marine Vessels and Human-Rated
Spacecraft and Related Support Equipment
    EPA is establishing a narrowed use limit that would allow continued
use of HFC-134a in centrifugal and positive displacement chillers for
military marine vessels as of January 1, 2024. EPA is also establishing
a narrowed use limit that would allow continued use of HFC-134a and R-
404A in centrifugal and positive displacement chillers for human-rated
spacecraft and related support equipment applications as of January 1,
2024. See section VI.A.4.a.iv and VI.A.4.b.iv of the proposed rule (81
FR 22844; April 18, 2016) for a discussion of the reasons for these
narrowed use limits. EPA responds to comments regarding the narrowed
use limits in section VI.A.5.c.v.
    Under these narrowed use limits, the end users will need to
ascertain that other alternatives are not technically feasible due to
performance or safety requirements, and they would also need to
document the results of their

analysis. See 40 CFR 82.180(b)(3). Users are expected to undertake a
thorough technical investigation of alternatives to the otherwise
restricted substitute. Although users are not required to report the
results of their investigations to EPA, users must document these
results and retain them in their files for the purpose of demonstrating
compliance. This information includes descriptions of:
     Process or product in which the substitute is needed;
     Substitutes examined and rejected;
     Reason for rejection of other alternatives, e.g.,
performance, technical or safety standards; and/or
     Anticipated date other substitutes will be available and
projected time for switching.
iii. When will the status change?
    EPA proposed and is finalizing a status change date of January 1,
2024, for new centrifugal chillers and new positive displacement
chillers, except as otherwise allowed under a narrowed use limit. The
status change date is based on comments and our understanding of the
needs for industry standards, model codes, and adoption of those items
to allow for a range of alternatives, including flammable alternatives,
in both types of chillers addressed. As pointed out by AHRI and NRDC in
their joint comment on the proposed rule, for chillers with
alternatives not subject to a status change to be used ``effectively
and safely, the appropriate mitigation must be developed, proven, and
finally adopted by safety standards. Only then can states and
municipalities adopt building codes reflecting the updated safety
standards.'' The Agency understands that relevant industry standards
and model building codes are likely to change in the 2017 to 2021
timeframe, and that such changes will be a necessary step for the
acceptable alternatives feasibly to be used in the chiller market.
These standards and codes include ASHRAE 15, UL 1995, UL 60335-2-40,
and the International Building Code (IBC). EPA also recognizes that
even once standards and model building codes are changed, time will be
required for locations to adopt such codes allowing for the use of
chillers using the alternative refrigerants, many of which may not
currently be allowed to be used based on existing codes. While some
non-flammable, code-acceptable refrigerants are available for some of
the chiller market, the use of other acceptable alternatives would
require code changes or exceptions made by code officials. Comments
indicated that there is a progression from the release of a model code
until adoption by State authorities, and that the majority of States
are currently using either the most recent (2015) model code or are
only one cycle behind (2012). While EPA does not believe the status
change date must occur after all such authorities have adopted a new
model code, we are allowing a reasonable time to provide that
opportunity where such code adoption would facilitate the introduction
of chillers with alternative refrigerants. Comments also indicate that,
if the appropriate codes are not adopted, there are alternative means
and measures that may be taken to allow the use of alternatives
otherwise not allowed. A change of status date of January 1, 2024, is
necessary to provide an expeditious yet reasonable time for this
process to occur. The status change date is also necessary to allow
continued development of designs of new centrifugal and positive
displacement chillers using an acceptable alternative, covering the
wide range of capacity and design types (low/medium pressure, indoor/
outdoor, etc.) that exist in the market, and allow those chillers to be
tested and certified. EPA is aware that some equipment has been
introduced with acceptable alternatives, as discussed above in section
VI.A.5.a.ii, and that additional research and development is underway
with these and other possible alternatives. EPA responds to comments
regarding the status change date in section VI.A.5.c.ii.
    Some commenters suggested an earlier date for all or parts of the
centrifugal and positive displacement chiller market, suggesting status
change dates as early as 2019. While EPA noted that multiple chillers
with alternative refrigerants are already available on the market now,
and we expect more to become so by that date, we did not find evidence
that a significant portion of the chiller market could transition at an
earlier date than the date we are finalizing. Further, EPA did not
receive enough technical detail to support dividing the centrifugal
chiller end-use or the positive displacement chiller end-use so that
different change of status dates could apply to different portions of
the end-uses.
    Commenters who suggested a later status change date had concerns
regarding their ability to maintain current energy efficiency levels
with alternative refrigerants. The data provided by commenters,
however, showed only minor theoretical losses of efficiency for some
alternatives, up to about four percent. These commenters suggested more
time is needed to recover these losses by redesigning and recertifying
centrifugal chillers. These losses are considered small and only
pertain to ``drop-in'' conditions; it is expected that any losses can
be recovered by designing new chillers to utilize those refrigerants,
as commenters indicate they expect to do. Furthermore, several
alternatives were found to exceed current efficiency levels even in
these theoretical conditions. While some commenters provided a general
description of the steps that must be taken in this redesign process,
none provided a detailed timeline of how long each step would take and
how multiple models can be redesigned in parallel during the proposed
timeframe. Therefore, we disagree that efficiency concerns would
support a later change of status date.
    Commenters who suggested a later status change date were also
concerned about the need to update industry standards and building
codes, and adoption of those codes, specifically for flammable
alternatives. For centrifugal chillers, they stated such changes must
take place for HFO-1234ze(E), a mildly flammable A2L refrigerant, to be
used. They also identified that refrigerant and several other A2L
refrigerants for positive displacement chillers, and likewise indicated
that standards and codes actions hindered the availability of chillers
with those alternatives. EPA found several examples where acceptable
alternatives have been used in both centrifugal and positive
displacement chillers, and received information that indicates that
industry standards are expected to be updated as early as 2017 and that
model building codes would be updated possibly in the 2018 cycle or
most likely the 2021 cycle. By establishing a 2024 status change, we
allow time for adoption of those model codes by States and other
jurisdictional authorities. In addition, commenters noted that there
are other alternative means and measures by which the use of a
flammable refrigerant, if so chosen by the manufacturer, in a
centrifugal or positive displacement chiller may be permitted, even if
that refrigerant were not otherwise allowed under a particular State or
locality's existing code requirements.
c. How is EPA responding to comments?
    EPA received several comments from individuals and organizations
with various interests in the refrigerants industry. Comments addressed
EPA's proposed status change date of January 1, 2024, for new
centrifugal chillers and new positive displacement chillers. Some
commenters, including Chemours, EIA, Honeywell, and Ingersoll Rand

supported EPA's proposed status change date. These commenters
identified a range of potential alternatives but generally agreed that
new centrifugal chillers using these alternatives needed some time to
be brought to the market. Other commenters opposed the proposed status
changes or suggested different change of status dates from the one EPA
proposed, such as 2021 and 2025. Other comments we received related to
energy efficiency, industry standards and codes, and the narrowed use
limits for military and spacecraft uses.
    Commenters included Boeing, Eastman Chemical Company, Honeywell,
Chemours, Johnson Controls, Ingersoll Rand, UTC, PSEG Services
Corporation, Arkema, the Alliance, National Association of
Manufacturers (NAM), AHRI, EIA, NRDC, IGSD, NASA, and DoD.
    As stated above, EPA received many comments discussing ``chillers''
or ``HFC-134a alternatives'' that did not specify whether the comments
applied specifically to centrifugal chillers, positive displacement
chillers, or both. 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). Our responses should be
considered as equally applicable to both end-uses unless otherwise
specified.
i. Substitutes and End-Use Proposed
    Comment: Eastman requested that EPA clarify whether the status
changes under the chiller end-uses apply to the IPR end-use. Eastman
pointed out that since the inception of the SNAP program, EPA has
separated these into different end-uses.
    Response: EPA confirms that this action will change the status of
refrigerants for new positive displacement chillers and new centrifugal
chillers and does not affect refrigerants listed under the separate IPR
end-use.
    Comment: Eastman raised concerns about retrofits to existing
equipment, specifically for ``any of these systems with remaining
useful life [that] are scheduled for retrofits due to previous phase-
outs of refrigerants such as R-22,'' and pointed out issues related to
using certain refrigerants listed as acceptable for the chiller end-
uses ``to replace the one the [IPR] system was originally designed to
use.'' PSEG submitted similar comments, requesting that EPA ``clarify
its intent that the prohibition of HFC-134a in chillers applies to new
chillers installed on or after January 1, 2024,'' and did not require
``units that are newly installed with HFC-134a after the final rule
becomes effective, but prior to January 1, 2024, to retrofit those
`existing' units by January 1, 2024.'' PSEG stated that ``there are few
viable zero or low GWP refrigerants available for use in HFC-134a large
tonnage equipment'' and that highly flammable refrigerants and both R-
717 and R-744 are not viable for nuclear applications, noting that
``the equipment must be designed specifically for the gas.''
    Response: The status changes to the centrifugal and positive
displacement chiller end-uses in this rule apply to ``new'' equipment
installed on or after the status change date of January 1, 2024. EPA
has historically issued separate decisions under the SNAP program for
new equipment in a given end-use and retrofit (i.e., the replacement of
the refrigerant with an alternate refrigerant) in the same end-use.
This action changes the status of refrigerants for new chillers created
on or after the status change date; it does not change the status of
refrigerants currently acceptable for retrofitting chillers. Thus,
concerns about retrofitting ``HFC-134a'' equipment are not pertinent
for this action.
    Comment: EIA supported EPA's proposal to change the status of high-
GWP refrigerants to unacceptable for centrifugal and positive
displacement chillers, mentioning specifically refrigerants HFC-134a,
R-404A, R-407C, R-410A and R-507A. Chemours also supported EPA's
proposed status changes for both chiller end-uses, and identified
several alternatives and what they would replace, including R-513A
(HFC-134a replacement), R-452B (R-410A replacement), R-449A (R-404A
replacement) and HFO-1234yf (HFC-134a replacement).
    Response: EPA thanks the commenters for their support of the
proposed rule. Regarding the alternatives identified by Chemours, EPA
agrees that R-513A is an acceptable alternative for centrifugal and
positive displacement chillers. EPA has received submissions for R-449A
and R-452B for both centrifugal and positive displacement chillers and
the Agency is reviewing them for these and other end-uses. We have not
received a submission specifically for HFO-1234yf in chillers.
    Comment: UTC provided information regarding various refrigerants
that are listed as acceptable or that may be under research for use in
centrifugal chillers, specifically HFO-1234ze(E), R-290, R-450A, R-
513A, R-452B, R-718, R-744, R-1233zd(E) and R-515A. They likewise
provided information on the first six of these refrigerants in positive
displacement chillers. Additional information regarding the compressor
displacement to utilize these alternatives was also provided. UTC noted
the flammability of R-290 and felt that R-718 and R-744 ``do not
provide a long-term solution or require additional work to make such
refrigerants feasible in chillers.'' UTC provided information regarding
the application and efficiency of the other refrigerants and said some
of these that could be used ``are short-term, but less efficient''
options. They also indicated others are ``longer-term,'' and identified
HFO-1234ze(E) as a specific example but also noted its flammability.
They stated that R-452B was not a viable option to replace HFC-134a but
did indicate it was under consideration as one of several R-410A
alternatives, all of which are flammable.
    Response: EPA interprets this comment to apply to both centrifugal
and positive displacement chillers. EPA thanks the commenter for this
information. This information shows that much is known about these
refrigerants and how they could be employed in chillers. UTC indicates
a desire to transition to what it considered ``longer-term'' solutions,
but did not provide adequate information to indicate why their
recommended status change date of January 1, 2025, would provide such
time but the proposed status change date of January 1, 2024, would not.
As discussed in section VI.A.5.b.iii above, EPA has established a
change of status date that considers the need for standards and model
codes to change to incorporate requirements for flammable refrigerants
as well as additional time for States and localities to adopt such
codes as part of their requirements.
    Comment: UTC indicated that HFO-1234ze(E) is flammable and
therefore mitigation is required and ``appropriate safety standards and
approved building codes must be in place before it can be used.''
Comments submitted as CBI indicate that a chiller using HFO-1234ze(E)
has been introduced in Europe and that the potential flammability of
the refrigerant was addressed through added mitigation requirements
sufficient for A2 (and hence A2L) refrigerants. As noted in section
VI.A.5.a.iii above, Honeywell stated that ``[s]everal manufacturers
currently offer high-efficiency chillers, air-cooled (outdoor) and
water-cooled (indoor), using HFO-1234ze(E) in sizes ranging from tens
of tons to hundreds of tons'' and listed some examples, including some
centrifugal chillers and some positive displacement chillers.

    Response: EPA interprets these comments as applying to both
centrifugal and positive displacement chillers. This information
indicates that manufacturers and installers have been successful in
introducing chillers with alternative flammable refrigerants in some
instances, and that building codes allow for such installations under
certain circumstances. However, as discussed in section VI.A.5.b.iii
above, EPA agrees that for flammable refrigerants to become more widely
used across the multiple applications and configurations where
centrifugal and positive displacement chillers are deployed, standards
and model codes need to be revised and the States and localities must
adopt such codes. Our status change date of January 1, 2024, provides
the time necessary for this to occur. As discussed above in section
VI.A.5.a.iii, multiple companies have introduced chillers using HFO-
1234ze(E). Comments indicate that this refrigerant is already being
employed in chillers and that steps to address the flammability of the
refrigerant in some applications are known. Thus, this refrigerant is
one of the many options that can be utilized by manufacturers to
develop chillers using acceptable refrigerants by the January 1, 2024,
status change date. In addition to HFO-1234ze(E), other flammable
refrigerants have been used, especially in positive displacement
chillers. For instance, in the proposed rule (81 FR 22847; April 18,
2016), EPA noted that ``R-717 has a long history of use as a
refrigerant in positive displacement chillers, especially in water-
cooled screw chillers, and other applications.''
    Comment: Honeywell stated that ``HFO-1233zd(E), has a GWP of one,
is non-flammable and more energy efficient than HFC-134a, and chillers
utilizing HFO-1233zd(E) are available from at least three
manufacturers,'' identifying Trane (a brand of Ingersoll Rand), Carrier
(a brand of UTC), and Mitsubishi Heavy Industries.
    Response: EPA thanks the commenter for this information regarding
R-1233zd(E). The proposed rule (81 FR 22842; April 18, 2016) noted that
one manufacturer had introduced a chiller using this refrigerant.\121\
That same company now offers all of their large tonnage low-pressure
centrifugal chillers using this refrigerant.\122\ As Honeywell notes,
and as we cite in section VI.A.5.a.iii above, other manufacturers have
also produced centrifugal chillers using R-1233zd(E). These will serve
part of the chiller market but do not satisfy the full market, for
instance where a smaller tonnage, positive displacement chiller is
required.
---------------------------------------------------------------------------

    \121\ Cooling Post, 2014. ``Trane first with 1233zd chiller.''
June 30, 2014. This document is accessible at http://www.coolingpost.com/world-news/trane-first-with-1233zd-chiller/.
    \122\ Trane, 2016. ``Trane Announces Significant Centrifugal
Chiller Line Expansion and Services for the United States and
Canada.'' June 15, 2016. This document is accessible at http://www.trane.com/commercial/north-america/us/en/about-us/newsroom/press-releases/centrifugal-chiller-line-expansion.html.
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    Comment: Ingersoll Rand stated that they will have small tonnage
low-pressure centrifugal chillers under their Trane brand using R-514A
available in 2017.
    Response: EPA thanks the commenter for this comment indicating the
development of small tonnage low-pressure centrifugal chillers using R-
514A, which we cite in section VI.A.5.a.iii.
    Comment: EIA suggested that EPA ``signal the likelihood'' of
finding alternatives with GWPs above 600 unacceptable, including R-450A
and R-513A.
    Response: EPA cannot, at this time, project what actions it may
take in the future. Moreover, any proposal to change the status of R-
450A and R-513A in the chiller end-uses would need to occur through a
separate notice and comment rulemaking in which EPA performs a full
comparative assessment using the SNAP criteria.
ii. Change of Status Date
    Comment: Honeywell supported a January 1, 2024, status change date
for chillers but felt that certain types could transition sooner. They
noted that the discussion regarding the need for building codes to
change to accept 2L flammable refrigerants was most applicable to
water-cooled indoor chiller installations and that ``for the most part
this issue does not impact the installation of air-cooled chillers that
are installed outdoors.'' Based on that, Honeywell believed that EPA
could adopt an earlier transition date for air-cooled (outdoor)
chillers. EIA suggested a staged transition with a change of status
date of January 1, 2019, for air-cooled chillers and January 1, 2021,
for water-cooled chillers. The California Air Resources Board (CARB)
recommended that all chillers be subject to a January 1, 2021, status
change date. Arkema suggested a 2021 transition date for R-407A, R-
407B, R-407C, R-407D, R-407E, and R-407F.
    Response: EPA interprets these comments as applying to both
centrifugal and positive displacement chillers. The commenters
supporting one or more earlier change of status dates for all or
portions of the chiller end use did not provide enough technical detail
to conclude that such dates are achievable for the chillers that would
be subject to such dates. Further, EPA did not receive enough
information regarding how extensive code changes would (or would not)
be specifically for air-cooled outdoor chillers and thus we do not
believe that an earlier status change date for that portion of the
chiller market as suggested by Honeywell and EIA is supported. EPA
notes that nonflammable (A1) and flammable (A2L and B2L) alternatives
are acceptable for both centrifugal and positive displacement chillers.
    We also recognize that it is important under the SNAP program to
not limit end users to a single choice. EPA has identified several
alternatives that are acceptable for centrifugal chillers and likewise
positive displacement chillers. By establishing the same change of
status date for all chillers, manufacturers will be able to choose from
the full list of acceptable alternatives the refrigerant(s) and chiller
type(s) that best meet their specific needs, and customers will be able
to apply the particular type(s) of chillers using the particular
acceptable alternative that best meet their needs. Individual
manufacturers may determine for themselves which alternative(s) to use
in their particular equipment and given the variety of alternatives
available there may not be a single ``widely-accepted'' replacement,
even for a specific type of chiller; there may be several refrigerants
and chiller types competing in the market. For additional comments
regarding building codes and standards, please see section VI.A.c.iv.
    Comment: UTC argued for a status change date no earlier than
January 1, 2025. One factor that they cited was that HFO-1234ze(E) ``is
a new HFO.'' Regarding this chemical, UTC stated that it has
``approximately equal performance'' to HFC-134a and indicated that
changes to equipment designs are required to use it. UTC also stated
that ``typical development projects require 2-3 years to complete,''
but indicated that HFO-1234ze(E) ``require[s] major redesign work.''
Commenting on positive displacement chillers, EIA stated that ``[t]he
first HFO-1234ze chillers were installed back in 2011 and production
uptake of HFO-1234ze chillers has been increasing rapidly'' noting two
major manufacturers--Carrier (a brand of UTC) and Trane (a brand of
Ingersoll Rand)--using that refrigerant in chillers.

    Response: EPA interprets UTC's comment as applying to both
centrifugal and positive displacement chillers while EIA's comment was
specific to positive displacement chillers. HFO-1234ze(E) is not a
``new'' refrigerant--it was added to ASHRAE Standard 34-2010 via
addendum i, which was approved by the ASHRAE Standards Committee on
June 25, 2011, by the ASHRAE Board of Directors on June 29, 2011, and
by the ANSI on June 30, 2011. EPA listed it acceptable for centrifugal
and positive displacement chillers on August 10, 2012. As discussed
previously in section VI.A.5.b.iii and as EIA noted, multiple companies
have utilized HFO-1234ze(E) in chillers to date. Finally, we note that
Carrier Corporation, a brand of UTC, has at least six HFO-1234ze(E)
chiller installations in Switzerland.\123\
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    \123\ RAC, 2016. ``Carrier opts for HFO 1234ze refrigerants for
global chiller range.'' February 26, 2016. This document is
accessible at http://www.racplus.com/news/carrier-opts-for-hfo-1234ze-refrigerants-for-global-chiller-range/10003440.article?blocktitle=News&contentID=15773.
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    Comment: UTC, Johnson Controls and AHRI stated that any status
change date earlier than January 1, 2025, would not provide the time
necessary to transition to alternatives that remain acceptable. UTC
stated that ``EPA must take into account certain properties, including
flammability, for refrigerants for which EPA does not propose to change
status'' (emphasis in the original), such as HFO-1234ze(E), R-
1233zd(E), R-450A and R-513A. UTC commented that the substitutes that
remain acceptable for centrifugal chillers and for positive
displacement chillers currently utilizing HFC-134a are not ``drop-in''
refrigerants and will require substantial equipment redesign to account
for displacement changes and changes in cycle efficiency and heat
transfer. For positive displacement chillers currently utilizing R-
410A, UTC and Johnson Controls said system changes must be made for A2L
refrigerants, and concluded that all the alternatives being
investigated for such use are or would be classified as A2L. UTC
provided further information on the steps required during redesign.
These included steps for ``each chiller type'' as well as additional
steps for 2L flammable refrigerants. To redesign equipment, UTC said
one necessary step was the development of oils and new materials to be
used in the new equipment. They also indicated that new components and
overall systems would need to be requalified by test laboratories. More
generally, UTC indicated that ``different equipment redesign,
requalification and equipment sensor and alarms will be required along
with state and local adoption of building and fire code changes'' to
transition positive displacement chillers.
    UTC said that typical development projects would require two to
three years to complete but also indicated that this time frame could
be delayed due to the availability of manufacturer and test labs for
certification, Johnson Controls indicated a project duration of two to
nine years for low-pressure and medium-pressure chillers. AHRI also
estimated it would take two to nine years to commercialize including
time to reengineer and re-optimize chillers to use alternative
refrigerants. Ingersoll Rand noted their commitment to transition its
entire chiller portfolio, including positive displacement screw and
scroll chillers, before the end of 2018.
    Response: EPA interprets these comments as applying (regarding the
development process) to both centrifugal and positive displacement
chillers. 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. EPA
recognizes that in many cases designs will need to be modified to use
different refrigerants. This is expected and was evidenced when
centrifugal chillers transitioned from CFC-11 and CFC-12 to HCFC-123
and HFC-134a and when positive displacement chillers transitioned from
CFC-12 and HCFC-22 to HFC-134a, R-407C and R-410A. Past experiences
show that such redesigns offer the opportunity for manufacturers to
integrate other changes to improve performance of their products and
could offer them competitive advantages in the market. EPA realizes
that the degree of design changes may vary by the refrigerant chosen
and more so from decisions by the manufacturers in adopting designs for
those refrigerants and including other design changes during the
process.
    The information from these commenters did not provide sufficient
detail to determine the time it would take to transition all chillers
to acceptable alternatives to serve its current market. For instance,
UTC did not indicate whether the two to three year product development
timeframe applied to just one or multiple products, and if the latter,
whether those development projects could overlap and occur
simultaneously. Johnson Controls and AHRI did not address these
situations either. However, the January 1, 2024, change of status date
for both centrifugal and positive displacement chillers that EPA is
establishing in the final rule should provide sufficient time for the
activities described by the commenters to occur in order to meet that
date.
    Comment: In addition to the argument for a change of status date no
earlier than January 1, 2025, UTC suggested that HFC-134a in chillers
should remain acceptable until states and localities adopted the
``relevant building, fire and mechanical codes that may be necessary.''
The commenter suggested a narrowed use limit could apply. UTC also
provided a table indicating the number of states adopting various
editions of the IBC, the International Fire Code, and the International
Mechanical Code. UTC indicated a desire for ``regulatory certainty''
and an avoidance of ``balkanization of the market.''
    Response: UTC did not indicate specifically which codes, and
specifically which provisions in any codes, would need to be modified.
Although EPA recognizes that in general standards and model codes need
to be developed to allow for the use of A2L refrigerants, and that
States and localities need to adopt those model codes or similar
requirements, it is not reasonable to condition the entire market by
such actions. As stated above in section VI.A.5.b.iii, a status change
date of January 1, 2024, provides a reasonable amount of time for these
actions to take place for most if not all States and localities. Where
such actions have not fully occurred, manufacturers have the option to
offer nonflammable refrigerants for some chiller types, and alternative
means and methods exist to allow for the use of A2L refrigerants if
needed.
    Further, as the table of approvals provided showed, various states
are adopting different cycles of codes, some dating back to 2003 and
others adopting the latest 2015 codes. In section VI.A.5.c.iv below,
EPA points to the concerted effort by DOE, AHRI, and ASHRAE to fund
vital research that will establish a more robust fact base about the
properties and uses of flammable refrigerants. The results from this
work will help provide the technical knowledge needed to facilitate and
accelerate the safe use of flammable refrigerants. EPA finds that
conditioning a status change on code adoption would not only be
unnecessary, but would create the ``balkanization'' or patchwork of
regulations that UTC said it wanted to avoid.
    Comment: AHRI and NRDC jointly stated that ``[t]he forthcoming
redesign

will require modification not only to the equipment itself, but also to
the manufacturing environment, servicing practices and shipping
logistics, and most importantly, to the equipment rooms and buildings
in which these equipment may be installed.'' AHRI and NRDC recommended
a January 1, 2025, change of status date to allow time for these
modifications to occur.
    Response: EPA interprets these comments as applying to both
centrifugal and positive displacement chillers. As discussed in the
previous response, EPA recognizes that equipment modification and
redesigns will be required to use alternatives. The commenters did not
indicate specifically why the other modifications were required, did
not provide any detail regarding the time needed for the identified
modifications, whether the various steps could be addressed in parallel
or only one after the other in series and why these steps cannot take
place in time to meet a January 1, 2024, change of status date. Thus,
these comments do not support a claim that the change of status date
should be January 1, 2025, instead of January 1, 2024, for either
centrifugal or positive displacement chillers.
    Comment: Arguing for a January 1, 2025, status change date, Johnson
Controls stated that the alternatives not subject to status change are
not ``drop-ins'' for HCFC-123 in low-pressure centrifugal chillers and
likewise that to transition HFC-134a chillers to low-pressure
alternatives would require redesign of heat exchangers and compressors
and take two to nine years or longer.
    Response: As noted above, 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. We recognize that manufacturers typically redesign products
to varying extents when transitioning refrigerants in most cases to
address the unique properties of the new refrigerant that will be used.
As an initial matter, EPA's change of status rule does not limit
manufacturers currently using HFC-134a to convert to low-pressure
alternatives. Higher-pressure alternatives that are not subject to
status change may also be considered, including HFO-1234ze(E), R-450A
and R-513A. In addition, manufacturers may develop and submit to SNAP
other alternatives for evaluation. Regardless, the commenter has
suggested a wide timeframe for the time in which it would take
manufacturers to convert equipment, but has provided no detail as to
the actual expected timeframe. We note that a January 1, 2024, change
of status date will provide the manufacturer slightly more than seven
years in which to achieve a conversion, which is on the later side of
the time they suggest might be needed. In addition, we note that the
commenter has already announced that the centrifugal and screw chillers
they offer, originally designed for HFC-134a, are compatible with R-
513A, which is not subject to the status change in this action.\124\
---------------------------------------------------------------------------

    \124\ Johnson Controls, 2016. ``Johnson Controls Advances
Environmental Sustainability with Chiller Platforms Compatible with
Low GWP Refrigerants.'' January 20, 2016. http://www.johnsoncontrols.com/media-center/news/press-releases/2016/01/20/advanced-environmental-sustainability-with-chiller-platforms-compatible-with-low-gwp-refrigerants.
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    Comment: AHRI stated that the flammability of new refrigerants will
require safety upgrades for manufacturing and reclamation facilities.
AHRI also indicated that transition to flammable refrigerants involves
capital investments that need to be planned well in advance.
    Response: AHRI did not provide any specific information on the time
required to prepare these facilities for flammable refrigerants and how
that might affect the proposed change of status date. We note that
neither of the two certified reclaimers that commented on the proposed
rule indicated that safety upgrades were needed and that a later change
of status date should be established to allow for such upgrades.
    Comment: Johnson Controls stated that the AHRI/NRDC proposal called
for a tremendously aggressive transition away from HFCs in just over
eight years and compared that time period to what they indicated was
over 20 years to transition chillers from CFCs and HCFCs. They stated
that after more than 25 years from the signing of the Montreal
Protocol, there are manufacturers still using HCFCs in chillers. AHRI
also stated that the last refrigerant transition from ODS has taken 20
years and is still in process.
    Response: EPA disagrees that a 2024 status change date is overly
aggressive or that the transition away from CFCs and HCFCs provides
support that an over seven-year period for moving away from the use of
many HFCs and HFC blends is insufficient. It is important to note that
the transition away from CFCs and HCFCs in the earlier years was due to
a phasedown, not a phaseout, of CFCs. While based on later regulations
CFCs were phased out of production in 1995, a phaseout in production of
HCFCs has only more recently started. Thus, during the first 15 years
of the SNAP program, there was no obligation and no incentive for
manufacturers to transition from HCFCs. Therefore, the pace of
transition away from HCFCs does not reflect the time needed to
transition away from the substitutes subject to the change of status.
As provided in more detail in section VI.A.5.b.iii, we evaluated the
steps it would take for manufacturers to transition chillers away from
the substitutes that we are changing the listing status to
unacceptability, examining the technical challenges for that transition
and considering the use of flammable alternatives and the related need
for changes to industry standards and model building codes and the
adoption of those codes. For the reasons provided there, we have
determined that January 1, 2024, is a reasonable, but expeditious date
for such a transition.
    Comment: The Alliance asked EPA to explain in more detail what
technical analysis or timelines would be needed to justify a change of
status later than our lead proposal of January 1, 2024.
    Response: EPA interprets this comment as applying to both
centrifugal and positive displacement chillers. EPA has not established
a specific list of items that are needed to justify a later change of
status date. In establishing a change of status date, EPA examined the
technical challenges in order to determine a reasonable, but
expeditious change of status date. Thus, to support a later change of
status date, EPA would need additional information indicating that the
information it relied on to support a January 1, 2024, change of status
date was flawed and that additional time was needed to meet the
technical challenges of a transition.
    Comment: Arkema provided a list of steps needed for ``product line
development'' including ``researching options, risk assessment,
analyzing existing manufacturing capabilities, working with component
suppliers, building test units, testing beta units, updating
manufacturing processes (including employee training), building pre-
production units, field testing, completing the customer approval
process, phasing in production, disposing of trapped inventory, and
training installation and maintenance personnel'' and ensuring
``products conform to local building codes.'' For new chillers
specifically, Arkema suggested a change of status date of 2025 for HFC-
134a and R-410A, stating as their ``[r]ationale'' that ``HFC-134a is
used in screw and centrifugal chillers;

[R-]410A is used in smaller chillers, especially scroll chillers.''
    Response: EPA interprets this comment as applying to both
centrifugal and positive displacement chillers. EPA agrees with the
commenter's indication of which types of chillers HFC-134a and R-410A
are currently used, but this does not provide any rationale for their
proposed change of status date for these refrigerants. Further, the
commenter did not provide any indication of how the product line
development tasks apply specifically to chillers and how they relate to
the change of status date proposed. The commenter did not provide any
justification to support a 2025 status change date instead of a change
of status date of January 1, 2024.
iii. Energy Efficiency
    Comment: Information submitted and claimed as CBI compared the full
load efficiency and the integrated part-load value (IPLV), another
measure of efficiency, of several alternatives relative to HFC-134a.
Similar information was included for eight alternatives relative to R-
410A. Given the number of alternatives shown, this information appears
to be based on theoretical calculations (e.g. ``cycle calculations'')
or tests of non-optimized equipment rather than a sample of equipment
in operation. The estimates showed that R-450A, R-513A, and R-515A had
lower full load efficiencies than HFC-134a (up to 3.3 percent below)
and that R-1233zd(E) and HFO-1234ze(E) had higher full load
efficiencies and IPLVs than HFC-134a (up to 3.1 percent above). The
information provided and claimed as CBI also indicated that some
refrigerants have better IPLVs (up to 2.3 percent higher) and some have
worse IPLVs (up to 2.5 percent lower) than HFC-134a in chillers. Of the
eight alternatives compared to R-410A, including for example HFC-32 and
R-452B, seven had higher IPLVs (up to 0.7 percent) and all eight had
higher full load efficiencies (up to 3.2 percent).
    UTC stated that ``the primary environmental impact (~95 percent) of
HVAC systems stems from the electric power needed to operate them, not
from refrigerant leaks (which constitute about five percent of the
overall impact).'' Johnson Controls and AHRI both stated that 98
percent of the CO2-equivalent emissions from chillers are
the result of the power. Johnson Controls claimed that medium-pressure
options to replace HFC-134a in chillers are two to four percent less
efficient in ``drop-in'' conditions while AHRI stated that some
acceptable alternatives ``may be two to three percent less efficient.''
Johnson Controls stated that ``the minimum efficiency of chillers is
mandated'' and indicated that it is unacceptable to offer lower-
efficiency equipment to their customers. They suggested that any loss
in efficiency might be possibly regained by increasing the surface area
of the heat exchangers and from modifying the aerodynamics of
compressors.
    Response: EPA interprets these comments as applying to both
centrifugal and positive displacement chillers. As discussed in section
VII.D.3 below, energy efficiency is not a specific criterion under
SNAP; however, manufactures indicated the desire to maintain or improve
efficiency with alternative refrigerants, and EPA is supportive of that
as well. The information provided shows that some options offer better
energy efficiency than refrigerants such as HFC-134a and R-410A
currently used in many chillers.
    While we agree with the commenters who suggest that certain
refrigerants may have a lower energy efficiency if used as ``drop-
ins,'' (i.e., without equipment modification), energy efficiency could
be addressed, as some commenters recognize, by adjusting design. The
change of status date allows time for such redesign to occur.
    It is unclear what the commenter is referencing when it states that
``minimum efficiency of chillers is mandated.'' EPA does not mandate
energy efficiency and, as we noted in the proposal (81 FR 22845; April
18, 2016), there are no specific DOE requirements for minimum energy
efficiency for chillers apart from those used in federal government-
owned buildings.\125\ It is reasonable to assume that Johnson Controls'
line of ``over 40 chiller product families'' already comes with varying
degrees of energy efficiency and that as they move forward to develop
systems that comply with the status change there will still be a range
of energy efficient products available.
---------------------------------------------------------------------------

    \125\ EPA stated in section VI.A.4.a.vi of the proposed rule (81
FR 22845; April 18, 2016) that DOE has established efficiency
requirements, based on ANSI/ASHRAE/IES Standard 90.1-2010, for
chillers used in federal buildings and provided our understanding of
that standard. Since that time, EPA has become aware that such
chiller efficiency requirements are now based on the 2013 version of
that standard (80 FR 68749; November 6, 2015).
---------------------------------------------------------------------------

    EPA also addresses energy efficiency in section VII.D.3 in this
action and in sections V.B.6.a, V.C.7, V.D.3.c, and VII.C.3 of the
preamble to the July 2015 rule (80 FR 42870; July 20, 2015).
    Comment: UTC indicated generally that while it would not face any
code barriers, ``an A1 [i.e., nonflammable] refrigerant may result in
reduced energy efficiency that may limit customer demand and drive
decisions to repair, and not replace, existing equipment.''
    Response: EPA interprets these comments as applying to both
centrifugal and positive displacement chillers. EPA recognizes that the
energy efficiency is a significant factor when choosing equipment. We
also recognize that the energy efficiency of any given piece of
equipment is in part affected by the choice of refrigerant and the
particular thermodynamic and thermophysical properties that refrigerant
possesses. We also do not believe that the evidence supports that the
change of status will result in end users needing to choose lower
efficiency equipment. As detailed in the previous comment and response,
the substitutes that will remain available provide both higher and
lower energy efficiencies than HFC-134a. Also, as noted by the
commenter in the previous comment and response, there are strategies
that manufacturers may pursue to mitigate against any loses in energy
efficiency.
    With respect to UTC's comment that reduced energy efficiency may
drive decisions to repair rather than replace existing equipment, EPA
does not dictate through the SNAP program when a chiller must be
replaced rather than repaired. Instead, EPA allows the user to
determine when to repair and when to replace their system.
iv. Industry Standards and Codes
    Comment: UTC stated that flammability is ``a new risk for comfort
cooling'' and that ``[s]afety cannot be compromised by setting
requirements ahead of the [ASHRAE] and [UL] standards.'' UTC, AHRI, and
Johnson Controls indicated that these standards would need to change to
allow for the safe use of alternatives, and that such changes would
only be a first step in that process. After that, model building codes
would need to incorporate the revised standards and then State and
local jurisdictions would adopt those codes, thereby making the use of
new alternatives viable in those locations. Commenters noted that HFO-
1234ze(E) is flammable and UTC listed eight options under consideration
to replace R-410A in positive displacement chillers and stated that
``[a]ll of these refrigerants are A2L and will require and [sic] update
of state and local codes.'' AHRI and NRDC jointly said ``[m]any
promising alternative refrigerants are mildly flammable (especially for
R-410A) and currently restricted under product safety standards and
building codes.'' The Alliance indicated ``[t]here has been notable
progress this year on the

challenge of incorporating the use of mildly flammable and flammable
low-GWP alternatives into the relevant codes and standards.'' Ingersoll
Rand stated that ``ASHRAE 15 and UL 60335-2-40 are being updated to
accommodate A2L refrigerants in chillers and are on track to be
complete by the end of 2017'' while EIA said ``ASHRAE Standards and
International Code Council (ICC) code changes required for adopting A2L
refrigerants . . . are already proposed and are expected to be
completed by 2018.'' AHRI pointed to an ``unprecedented effort''--a
$5.2 million program jointly funded by AHRI, ASHRAE and DOE--to
undertake independent research to allow flammable refrigerants to be
used safely in air conditioning and refrigeration equipment.
    Response: EPA interprets these comments as applying to both
centrifugal chillers and positive displacement chillers. These comments
indicate that the process of updating standards for flammable
refrigerants is underway and expected to be completed shortly. The
results of this research announced by DOE, ASHRAE, and AHRI will
immediately be transmitted to the committees responsible for ANSI/
ASHRAE Standard 15-2013, ``Safety Standard for Refrigeration Systems,''
and ANSI/ASHRAE Standard 34-2013, ``Designation and Safety
Classification of Refrigerants,'' with a goal of using the results to
update the standards as soon as possible, subject to full compliance
with the ANSI consensus process. EPA is encouraged by this $5.2 million
program as part of the ongoing global effort to identify appropriate
climate-friendly alternatives and the announcement that another
$500,000 has been pledged for this work.\126\ While EPA acknowledges
that additional time may be needed to adopt such standards in codes, or
provide other means for approval of the use of chillers with flammable
refrigerants by authorities having jurisdiction, such time is provided
through our January 1, 2024, status change date. Furthermore, EPA has
noted that nonflammable alternatives are available for both centrifugal
and positive displacement chillers, especially for designs currently
using HCFC-123 or HFC-134a. While commenters stated that the
alternatives for positive displacement chillers currently using R-
410A--such as those listed by UTC--are flammable, this does not
preclude the possibility of designing a chiller using a nonflammable
alternative nor as mentioned the revision of standards to allow the use
of flammable refrigerants, the incorporation of those standards into
model building codes, and the adoption of these building codes.
---------------------------------------------------------------------------

    \126\ EPA, 2016c. A ``Cool'' Way to Combat Climate Change under
the Montreal Protocol. July 20, 2016. Available online at https://blog.epa.gov/blog/2016/07/a-cool-way-to-combat-climate-change/.
---------------------------------------------------------------------------

    Comment: AHRI and NRDC maintained that ``appropriate mitigation
must be developed, proven, and finally adopted by safety standards''
before they can be used. They said that ``product and safety standards
will not be updated until 2018 at the earliest'' and that model
building codes reflecting those updates were expected in 2021. NAM and
UTC likewise indicated that state and local adoption of building and
fire codes was necessary for chillers to use 2L refrigerants, including
HFO-1234ze(E) and alternatives for R-410A positive displacement
chillers. UTC provided an undated table that showed the number of
states that had adopted various editions (from 2003 to 2015) of three
different codes. UTC said the process for adoption typically takes 8-10
years. They stated that they ``do not expect model codes to be
completely updated until 2021.'' Johnson Controls and AHRI also
provided information on code adoption by states. AHRI claimed that
historically it has taken on average up to 10 years to adopt updated
building codes and listed the four states using the 2006 or older IBC.
AHRI stated that a January 1, 2025, transition date is reasonable
``based on the assumption that the HVAC industry would work together
with the Federal government to accelerate the adoption of the standards
and codes necessary to allow for commercialization of the products.'' A
private citizen pointed out that codes produced by the ICC, including
the IBC, ``allows the jurisdiction to accept new methods and materials,
so long as that acceptance doesn't reduce the level of safety provided
by a code compliant material or method.'' This would indicate that a
manufacturer or other interested party could develop chillers using
those refrigerants and provide additional risk mitigation techniques
that could then be deemed as acceptable under the codes, even if the
codes did not specifically address the requirements to use 2L
refrigerants in such equipment. The citizen indicated that a subsidiary
company to the ICC can provide manufacturers with reports of its
assessment of such new products or methods, and that manufacturers in
turn can share that report with jurisdictions to demonstrate the
product meets the intent of the code. This would then allow the use of
that chiller, and possibly others, using 2L refrigerants in that
particular jurisdiction. Finally, the citizen noted two examples where
code changes are being undertaken that would ``more appropriately
address'' the use of A2L refrigerants. NRDC and IGSD pointed to
``several mechanisms'' by which individual building codes may be
modified by 2018 to allow for A2L refrigerants to be used. They further
pointed out that even without such measures building codes are expected
to allow the use of A2L refrigerants if a ``very high level of
ventilation and explosion-proof electronics are used.'' They concluded
that ``states with old codes will not truly be off limits to
manufacturers using mildly flammable refrigerants in their chillers.''
    Response: EPA interprets these comments as applying to both
centrifugal chillers and positive displacement chillers. The comments
provided indicated that some changes could be incorporated into the
model codes 2018 cycle. Nonetheless, EPA agrees with other commenters
that the integration of appropriate changes to the model codes may not
occur until the 2021 cycle, and as explained in section VI.A.5.b.iii
above, finds that a January 1, 2024, change of status date, which
allows three years for State and local adoption of the 2021 model code,
is appropriate under such circumstances. AHRI is one of three entities
that announced a new research program between the HVAC industry and the
Federal government that ``will provide the technical knowledge needed
to facilitate and accelerate the safe use of these refrigerants.''
\127\ As the table provided by UTC shows, some states were already
using the most recent (2015) codes and the majority were just one cycle
(i.e., 2012) behind as of early 2016. This would imply that many states
will be able to adopt the 2021 codes by the 2024 status change date.
UTC, Johnson Controls, AHRI, and NRDC did not address whether
amendments could be made, either to the codes themselves or to state
and local adoptions of the codes, without full adoption of a specific
cycle of building codes, providing the necessary changes, if any, to
allow chillers with acceptable alternatives to be used after the status
change date, but other comment provide evidence of such possibility.
UTC, Johnson Controls, and AHRI also did not address whether
alternative means and measures, such as those discussed by the private
citizen

and NRDC jointly with IGSD, could be taken to obtain approval from the
authority having jurisdiction to approve the use of such chillers where
a state or locality had not otherwise adopted the building codes
suggested as needed. Finally, considering UTC, Johnson Controls, and
AHRI are aware that some state adoptions lag the most recent codes by
up to 12 years, it is logical to assume there would be plans to address
such adoptions if they were to persist past their proposed status
change date of 2025, which is only four years after the code cycle that
their comments presume will allow for implementation of A2L options.
UTC, Johnson Controls, and AHRI, did not provide any details on such
plans, or why they could not equally be implemented by the 2024 status
change date, apart from AHRI's assumption of Federal government
assistance and further announcements of such. EPA is not aware that any
part of the Federal government was represented or consulted when the
AHRI Chiller Section and NRDC agreed to recommend a January 1, 2025,
transition date; however, we do note subsequent to the AHRI Chiller
Section and NRDC letter announcing this agreement, DOE along with AHRI
and ASHRAE, announced the $5.2 million effort ``that will establish a
more robust fact base about the properties and the use of flammable
refrigerants'' with an intent to update standards.\128\
---------------------------------------------------------------------------

    \127\ AHRI, 2016. ``AHRI, ASHRAE, DOE Partner to Fund Flammable
Refrigerant Research.'' June 2, 2016. This document is accessible at
http://www.ahrinet.org/News-Events/News-and-Shipping-Releases.aspx?A=1170.
    \128\ ASHRAE, 2016. ``ASHRAE, AHRI, DOE Partner to Fund
Flammable Refrigerant Research.'' June 2, 2016. This document is
accessible at https://www.ashrae.org/news/2016/ashrae-ahri-doe-partner-to-fund-flammable-refrigerant-research.
---------------------------------------------------------------------------

    Comment: UTC maintained that where codes did not allow the use of
A2L refrigerants after the status change date, businesses' only option
would be to repair a less efficient system. Elsewhere UTC stated that
another possibility would be for customers to use a packaged product or
variable refrigerant flow system.
    Response: EPA interprets these comments as applying to both
centrifugal chillers and positive displacement chillers. As previously
noted, EPA believes that the change of status date of January 1, 2024,
allows sufficient time for adoption of industry standards and changes
to relevant codes. In determining a change of status date, EPA does not
simply pick the latest date by which the Agency can be certain that all
codes will be updated. To the extent there may be codes that have not
been modified by the change of status date, users will have several
options in addition to the option of repair of an existing system or
use of a non-chiller system. As noted in the preamble and in
information in the docket to this rule, multiple chillers using
nonflammable refrigerants are available today and others have been
announced for release by 2017. Both Ingersoll Rand and Johnson Controls
have indicated a full line of centrifugal chillers using nonflammable
options. These two companies also have nonflammable options for
positive displacement chillers. Although commenters indicated the only
options currently being investigated for positive displacement chillers
currently using R-410A are flammable refrigerants, there is sufficient
time to develop, certify and release such chillers prior to the change
of status date.
v. Narrowed Use Limits for Military Marine Vessels, Human-Rated
Spacecraft, and Related Support Equipment
    Comment: Boeing, Chemours, and the Department of Defense (DoD)
supported EPA's proposal to find HFC-134a acceptable, subject to
narrowed use limits for centrifugal and positive displacement chillers
on military marine vessels. In addition to the reasons discussed in the
proposed rule (81 FR 22844; April 18, 2016), comments submitted by the
Department of the Navy on behalf of DoD addressed several alternatives
that are acceptable for chillers and not subject to status change that
have been found to not meet the stringent requirements for military
marine vessels. For instance, DoD pointed out that certain alternatives
that are flammable, such as HFO-1234ze(E) and R-717, would not meet the
DoD's requirements. While in stationary applications the flammability
may be handled, for instance, by increased ventilation, this is not a
practical solution for submarines or surface-going ships under warfare
conditions. DoD also discussed R-1233zd(E), noting that it would be
used in low-pressure chillers that are not acceptable for narrow
military uses due to reliability and maintenance issues. Boeing also
reiterated that ``testing of alternate refrigerants or blowing agents
for these niche markets may require more time than for mass-market
commercial items, due to customer and regulatory agency approval
requirements.''
    Response: EPA interprets these comments as applying to both
centrifugal and positive displacement chillers. EPA agrees with the
assessment made by DoD of specific technical issues in transitioning
for military marine vessels and is finalizing the narrowed use limit.
Because EPA is finalizing a status change date of January 1, 2024 for
this refrigerant in other chillers, the narrowed use limit would
likewise start on January 1, 2024.
    Comment: Boeing, Chemours, and NASA supported EPA's proposal to
find HFC-134a and R-404A acceptable subject to narrowed use limits for
centrifugal and positive displacement chillers for human-rated
spacecraft and related support equipment. Although NASA anticipates
using this narrowed use limit for only a small number of chillers, they
indicated that critical properties of the chiller system were required
for such applications that include ground-based assembly, integration
and test operations, and launch of the spacecraft.
    Response: EPA interprets these comments as applying to both
centrifugal and positive displacement chillers. EPA agrees with the
assessment made by NASA and is finalizing the narrowed use limit.
Because EPA is finalizing a status change date of January 1, 2024 for
these refrigerants in other chillers, the narrowed use limit would
likewise start on January 1, 2024.
6. Change of Status Listing for Certain HFC Refrigerants for New Cold
Storage Warehouses
a. Background
i. What is the affected end-use?
    Cold storage warehouses are temperature-controlled facilities used
to store meat, produce, dairy and other products that are delivered to
other locations for sale to the ultimate consumer. This end-use within
the SNAP program describes an application of refrigeration equipment
for an intended purpose, and hence the listings of acceptable and
unacceptable refrigerants for this end-use apply regardless of the type
of refrigeration system used.
    As explained in the proposed rule (81 FR 22849; April 18, 2016),
cold storage warehouses are usually deemed ``private'' or ``public,''
and some may be both, describing the relationship between the owner or
operator of the cold storage warehouse and the owner of the products
stored within.
    Cold storage warehouses are also often divided into two general
uses: ``coolers'' that store products at temperatures above 32 [deg]F
(0 [deg]C) and ``freezers'' that store products below this temperature.
Some subdivisions of these types were also provided in the proposed
rule (81 FR 22849; April 18, 2016).
    We explained that several other end-uses under the SNAP program
cover other parts of the food (and product) cold chain and are distinct
from the cold storage warehouse end-use. We

drew distinctions between the ``cold storage warehouse'' end-use which
is subject to this action and the IPR end-use while noting that many
facilities may have operations and refrigeration equipment for both
end-uses. We also discussed ``refrigerated food processing and
dispensing equipment,'' which is a category of the ``retail food
refrigeration'' end-use and is subject to separate decisions in this
action (see section VI.A.7). Finally, we discussed ``cold rooms'' and
``walk-in'' coolers and freezers, noting that many used for storage of
food and beverages at a retail food location (e.g., a supermarket or
restaurant) are considered to fall within other retail food
refrigeration end-use categories that were covered by a previous rule
(80 FR 42870; July 20, 2015). See section VI.A.4.c.i of the proposed
rule for background on the cold storage warehouse end-use (81 FR 22849-
51; April 18, 2016).
    EPA understands that existing cold storage warehouses may undergo
expansion to handle needs such as increased production, consolidation
of distribution points, or increased population or other reasons for
increased demands of the products stored. Such expansions could include
a physical expansion of the storage space or using racking techniques
to increase the amount of product within a given facility. The owner of
cold storage warehouses undergoing such expansions (or the owner's
designer) may determine that a new system needs to be added. That new
system could be a complete newly manufactured system separate from the
existing system, or it could be equipment and refrigerant added to the
existing system increasing the capacity of the existing system. In both
cases, EPA considers these actions as the manufacturing of a new system
and hence that equipment is affected by the changes of status in this
final rule.
    A commenter stated that cold storage warehouses are ``typically
designed with planned expansions'' and that the change of status should
not apply to any future expansion of such warehouses. EPA addressed the
definition of a ``new'' system as used in the SNAP program in a
previous rule (80 FR 42902-03; July 20, 2015). As explained there,
consistent with the definition in 40 CFR part 82, subparts A and I, EPA
considers a system to be new for purposes of these SNAP determinations
as of the date upon which the refrigerant circuit is complete, the
system can function, the system holds a full refrigerant charge, and
the system is ready for use for its intended purposes. Therefore, as
used in the SNAP program, ``new'' refers to the manufacture and often
installation of a refrigeration system for an intended purpose, which
may occur on a newly manufactured or an existing cold storage
warehouse. The status changes in this action would apply to the
expansion of the refrigeration system in an existing cold storage
warehouse if the capacity of that existing refrigeration system is
increased to handle the expansion. Because the existing system capacity
was inadequate to provide the necessary cooling for the expanded load,
the existing system did not meet the intended purpose of the expanded
capacity, and therefore if it were expanded to hand that load it would
be considered ``new'' with respect to SNAP. On the other hand, if an
existing refrigeration system is extended (for instance, by adding
additional refrigerant lines and evaporators to a newly manufactured or
newly commissioned building, to a portion of the existing facility
previously not used for cold storage, or to an extension of the
previous building), without requiring an increase in capacity and while
only needing the same full refrigerant charge as before, the system is
not considered ``new'' and hence may continue its operations with the
existing refrigerant. Likewise, a facility may increase the amount of
products it handles while at the same time providing better sealing
around infiltration points and/or increasing the insulation on walls
and roofs, and thereby avoid the need to increase the refrigeration
capacity of the equipment serving the cold storage warehouse.
    Commenters suggested divisions in the cold storage warehouse market
by which EPA should finalize separate decisions. One suggestion was to
distinguish between indirect and direct systems. In today's action, EPA
is not subdividing the cold storage warehouse end-use based on whether
a direct or indirect system is used. As addressed below, the commenter
suggesting this subdivision, and different change of status decisions
for the two subdivisions, did not provide evidence how any of the SNAP
criteria varied between the two subdivisions, instead only addressing
energy efficiency and economic burden.
    Another comment suggested a distinction between those cold storage
warehouses with a footprint of 3,000 square feet (279 square meters) or
less, noting they are covered by DOE energy conservation standards for
walk-in coolers and freezers, a point brought out in the proposed rule
(81 FR 22853; April 18, 2016). A commenter stated that EPA should
consider all such cold storage warehouses to be part of the retail food
refrigeration end-use because manufacturers make equipment that could
be used for retail food refrigeration or could be used in a manner that
would be classified as a cold storage warehouse within SNAP. In today's
action, EPA is not changing the definition of the cold storage
warehouse end-use such that some types are considered a different end-
use by virtue of their size. As addressed below, comments suggesting
this subdivision did not provide evidence how any of the SNAP criteria
varied between these two subdivisions. Although comments as well as the
proposed rule noted that such types of cold storage warehouses are
subject to DOE energy conservation regulations, the comments did not
indicate how this fact would change the availability of acceptable
alternatives by the change of status date proposed.
    An equipment manufacturer commented that many industrial processors
have multiple cold storage warehouses on the same campus and that these
may be cooled from a system that also provides cooling to other
applications, such as an industrial process refrigeration system. The
manufacturer stated that EPA should ``treat campuses with multiple
building and processing areas as one complete industrial process.'' EPA
notes, however, that SNAP decisions are on an end-use basis, and
therefore any cold storage warehouse may only use a refrigerant listed
as acceptable for that end-use. While through today's action EPA is not
changing the status of refrigerants in the industrial process
refrigeration end-use, we are doing so for new cold storage warehouses,
and as such some refrigerants in this end-use will be listed as
unacceptable as of the change of status date.
    EPA is not aware of other federal rules applying to efficiency of
cold storage warehouses (i.e., the buildings), but we find that some
federal rules apply to equipment that could be used in this specified
end-use. Specifically, EPA noted in the proposed rule (81 FR 22853;
April 18, 2016) that air-cooled commercial unitary air conditioners and
heat pumps (``CUACs'' and ``CUHPs'') might be applied at cold storage
warehouses, and such equipment is subject to DOE energy conservation
standards. Comment from NRDC and IGSD confirmed that cold storage
warehouses, among other types of designs, could be outfitted with
rooftop units that must comply with the DOE rule, and that
``[m]anufacturers are expecting to begin using HFC-32, R-452B, and
other A2L-class refrigerants in rooftop units in 2023 at the latest.''
For further information on the

relationship between this action and other federal rules, see section
VI.A.4.c.v of the proposed rule (81 FR 22853; April 18, 2016).
ii. What other types of equipment are used for similar application but
are not covered by this section of the rule?
    EPA has found several not-in-kind systems (i.e., systems that
operate using thermodynamic cycles other than vapor-compression)
acceptable for this end-use, including ammonia absorption, evaporative
cooling, desiccant cooling, and Stirling cycle systems, which are not
subject to this action.
iii. What refrigerants are used in cold storage warehouses?
    In section VI.A.4.c.i of the proposed rule, EPA indicated that R-
717 is believed to be the most common refrigerant used in cold storage
warehouses and provided information on equipment types and system
designs that facilitate the use of that refrigerant (81 FR 22850-22851;
April 18, 2016).
    We noted that limitations on the use of R-717 do exist. For
example, it is reported that charge sizes exceeding 10,000 pounds of R-
717 ``may require government-mandated process safety management (PSM)
and [a] risk management plan (RMP).'' \129\ Various state and local
building codes could also apply, and adherence to such codes might
hinder or even eliminate the use of R-717 in some cold storage
warehouses. Likewise, regulations may require employing operators with
special levels of expertise, reporting of use or accidental releases,
and other actions not typically required for other alternatives,
increasing the operating cost compared to facilities using other