\17\ The analysis included stand-alone retail food refrigeration
equipment and coolers; vending machines; refrigerated transport;
water coolers; commercial ice machines; household refrigerators and
freezers; and room air conditioners (window AC, PTAC, and PTHP). The
analysis did not expressly break out very low temperature
refrigeration or non-mechanical heat transfer from commercial
refrigerators and freezers.
    \18\ Refrigerants in this scenario included propane, isobutane,
and R-441A in the end-uses where they are listed to be acceptable,
subject to use conditions, among others. Ethane was not expressly
included, since the type of equipment using ethane is not broken out
separately in the analysis. However, ethane is less reactive than
the other refrigerants included in the analysis, so this omission is
expected to result in a slight overestimation of impacts, if any.
---------------------------------------------------------------------------

    Based on this still conservative but more probable assessment of
refrigerant use, we found that even if all the refrigerant in
appliances in end-uses addressed in this final rule were to be emitted,
there would be a worst-case impact of 0.15 ppb ozone in the Los Angeles
area, which is the area with the highest level of ozone pollution in
the United States. In the other cities examined in the analysis,
Houston and Atlanta, impacts were smaller (no more than 0.03 and 0.01
ppb, respectively) (ICF, 2014a). Because both the highly conservative
as well as the conservative but more probable assessments indicated
there would be relatively low air quality impacts of these refrigerants
if they are released to the atmosphere in limited amounts, EPA believes
that these refrigerants would not have a substantially greater impact
on local air quality than other refrigerants listed as acceptable in
the end-uses in this final rule.
    Effects on aquatic life of the substitutes are expected to be small
and pose no greater risk of aquatic or ecosystem effects than those of
other available substitutes for these uses. The refrigerant substitutes
in this rule are all highly volatile and would evaporate or partition
to air, rather than contaminate surface waters.

B. Flammability

    The flammability risks of the substitutes are of concern because
household and retail food refrigerators and freezers and room AC units
have traditionally used refrigerants that are not flammable. Without
appropriate use conditions, the flammability risk posed by these
refrigerants could be higher than non-flammable refrigerants because
individuals may not be aware that their actions could potentially cause
a fire, and because without the requirements of this rule, these
refrigerants could be used in existing equipment that has not been
designed specifically to minimize flammable risks. In this section, we
discuss the flammability risks posed by the refrigerants in this rule
and explain the use conditions we believe are necessary to mitigate
those risks to ensure that the overall risk to human health and the
environment posed by these substitutes is not greater than the overall
risk posed by other substitutes in the same end-uses. In addition, we
discuss why the flammability risks have led us to find that these
substitutes are only acceptable for use in new equipment specifically
designed for these flammable refrigerants.
    Due to their flammable nature, ethane, isobutane, propane, HFC-32,
and R-441A could pose a significant safety concern for workers and
consumers in the end-uses addressed in this rule if they are not
handled correctly. In the presence of an ignition source (e.g.,

static electricity spark resulting from closing a door, using a torch
during service, or a short circuit in wiring that controls the motor of
a compressor), an explosion or a fire could occur when the
concentration of refrigerant exceeds its LFL. The LFLs of the
substitutes are: ethane--30,000 ppm; HFC-32--139,000 ppm; isobutane--
18,000 ppm; propane--21,000 ppm; and R-441A--20,500 ppm. Therefore, to
use these substitutes safely, it is important to minimize the presence
of potential ignition sources and to reduce the likelihood that the
levels of ethane, HFC-32, isobutane, propane, or R-441A will exceed the
LFL.
    To determine whether flammability would be a concern for
manufacturing and service personnel or for consumers, EPA analyzed a
plausible worst-case scenario to model a catastrophic release of the
refrigerants. The worst-case scenario analysis for each refrigerant
revealed that even if the unit's full charge is emitted within one
minute, none of these refrigerants reached their respective LFLs of
1.8% for isobutane, 2.1% for propane, 2.05% for R-441A, or 3.0% for
ethane, provided that the charge sizes were no greater than those
specified in the relevant standard from UL (ICF,
2014b,c,d,e,f,g,h,i,j,k). Thus, there would not be a significant risk
of fire or explosion, even under those worst-case assumptions, so long
as the charge meets the use conditions in this final rule. Detailed
analysis of the modeling results are discussed below in the next
section regarding ``Toxicity and asphyxiation.''
    EPA also reviewed the submitters' detailed assessments of the
probability of events that might create a fire and engineering risk and
approaches to avoid sparking from the refrigeration equipment. Further
information on these analyses and EPA's risk assessments are available
in public docket EPA-HQ-OAR-2013-0748 at www.regulations.gov. Although
the analysis showed no potential for the released refrigerant from one
piece of equipment to reach the LFL, manufacturing and service
personnel or consumers may not be familiar with refrigeration or AC
equipment containing a flammable refrigerant. Therefore, use conditions
are necessary to ensure that people handling such equipment are aware
that the equipment contains a flammable refrigerant and to ensure safe
handling. Because of existing OSHA and building code requirements, we
expect that the equipment manufacturer, who would be storing large
quantities of the refrigerant, is familiar with and uses proper safety
precautions to minimize the risk of explosion. We are including in the
``Further Information'' section of the SNAP listings recommendations
that these facilities be equipped with proper ventilation systems and
be properly designed to reduce possible ignition sources. The use
conditions allow the flammable refrigerants to be used without a higher
risk to human health and the environment than that posed by
nonflammable substitutes.

C. Toxicity and asphyxiation

    In evaluating potential toxicity impacts of ethane, HFC-32,
isobutane, propane, and R-441A on human health, EPA considered both
occupational and consumer risks. EPA investigated the risk of
asphyxiation and of exposure to toxic levels of refrigerant for a
plausible worst-case scenario and a typical use scenario for each
refrigerant. In the worst-case scenario of a catastrophic leak, we
modeled release of the unit's full charge within one minute into a
confined space to estimate concentrations that might result. We
considered a conservatively small space appropriate to each end-use,
such as a small convenience store of 244 m\3\ for retail food
refrigeration, a small galley kitchen of 18 m\3\ for a household
refrigerator/freezer, or a small bedroom of 41 m\3\ for a room air
conditioner.
    To evaluate toxicity of all five refrigerants, EPA estimated the
maximum TWA exposure both for a short-term exposure scenario, with a
15-minute and 30-minute TWA exposure, and for an 8-hour TWA that would
be more typical of occupational exposure for a technician servicing the
equipment. We compared these short-term and long-term exposure values
to relevant industry and government workplace exposure limits for
ethane, HFC-32, isobutane, propane, and components of R-441A (including
potential impurities). The modeling results indicate that both the
short-term (15-minute and 30-minute) and long-term (8-hour) worker
exposure concentrations would be below the relevant workplace exposure
limits, such as the OSHA permissible exposure limit (PEL), the NIOSH
recommended exposure limit (REL), the American Conference of
Governmental Industrial Hygienists' (ACGIH) TLV, or in the case of HFC-
32, the manufacturer's recommended workplace exposure limit. In some
cases where there was not an established short-term exposure limit
(STEL), we considered information on short-term exposure such as the no
observed adverse effect level (NOAEL) from available toxicity studies
or the National Research Council's Acute Emergency Guideline Limits
(AEGL).\19\ The respective workplace exposure limits we considered for
the various compounds, including components of the refrigerant blend R-
441A, are as follows:
---------------------------------------------------------------------------

    \19\ The AEGL limit is an emergency guideline for exposures to
the general population (including susceptible populations) and is
not time-weighted. It also considers the chemical's flammability in
addition to its toxicity. EPA develops a set of AEGL values for
chemical for five exposure periods (10 and 30 minutes, 1 hour, 4
hours and 8 hours). For each exposure period, three different AEGL
values are developed to address different levels of toxicological
impacts. Of relevance for the modeled scenarios is the AEGL-1
(10,000 ppm), which is defined as: ``the airborne concentration,
expressed as parts per million or milligrams per cubic meter (pm or
mg/m\3\) of a substance above which it is predicted that the general
population including susceptible individuals, could experience
notable discomfort, irritation, or certain asymptomatic nonsensory
effects. However, the effects are not disabling and are transient
and reversible upon cessation of exposure.'' While permanent
toxicological effects are not expected up to the AEGL-2 value, this
limit is not relevant for this analysis because at that level,
flammability would be a greater concern.
---------------------------------------------------------------------------

     n-Butane, a component in R-441A: 800 ppm NIOSH REL on 10-
hr TWA; 6,900 ppm AEGL-1 over 30 minutes
     Ethane: 1,000 ppm TLV on 8-hour TWA; 3,000 ppm over 15
minutes
     HFC-32: 1,000 ppm manufacturer's exposure guideline on 8-
hour TWA; 3,000 ppm over 15 minutes
     Isobutane: 800 ppm REL on 10-hr TWA; 6,900 ppm over 30
minutes
     Propane: 1,000 ppm PEL on 8-hr TWA; 6,900 ppm AEGL-1 over
30 minutes
    For equipment with which consumers might come into contact, such as
retail food refrigerators and freezers, vending machines, household
refrigerators and freezers, and room air conditioners, EPA performed a
consumer exposure analysis. In this analysis, we examined potential
catastrophic release of the entire charge of the substitute in one
minute under a worst-case scenario. We did not examine exposure to
consumers in very low temperature refrigeration, since such equipment
is typically used in workplaces, such as in laboratories, and not in
homes or public spaces. The analysis was undertaken to determine the
15-minute or 30-minute TWA exposure levels for the substitute, which
were then compared to the toxicity limits to assess the risk to
consumers.
    EPA considered toxicity limits for consumer exposure that reflect a
short-term exposure such as might occur at home or in a store or other
public setting where a member of the general public could be exposed
and could then escape. Specific toxicity limits that we used in our
analysis of consumer exposure include:

     n-Butane: 6,900 ppm AEGL-1 over 30 minutes
     HFC-32: cardiotoxic NOAEL of 350,000 ppm over 5 minutes
     Isobutane: 6,900 ppm over 30 minutes
     Propane: 6,900 ppm AEGL-1 over 30 minutes
    The analysis of consumer exposure assumed that 100 percent of the
unit's charge would be released over one minute, at which time the
concentration of refrigerant would peak in an enclosed space, and then
steadily decline. Refrigerant concentrations were modeled under two air
change scenarios, believed to represent the baseline of potential flow
rates for a home or other public space, assuming flow rates of 2.5 and
4.5 air changes per hour (ACH) (Sheldon, 1989). The highest
concentrations of the refrigerant occur in the lower stratum of the
room when assuming the lower ventilation level of 2.5 ACH. Calculating
the TWA exposure using 2.5 ACH results in a higher concentration than
calculating the TWA exposure using 4.5 ACH. Even under the very
conservative assumptions used in the consumer exposure modeling, the
estimated 15-minute or 30-minute consumer exposures to the refrigerants
are much lower than the relevant toxicity limits and thus should not
pose a toxicity risk any greater than that of other acceptable
refrigerants in the end-uses in this final rule. Other acceptable
refrigerants pose similar toxicity risks.
    For further information, including EPA's risk screens and risk
assessments as well as fault tree analyses from the submitters of the
substitutes, see docket number EPA-HQ-OAR-2013-0748 at
www.regulations.gov.

V. What are the differences between the proposed and final rules?

    This final rule lists all five refrigerants as acceptable, subject
to use conditions, in the same end-uses as in the proposed rule. This
final rule retains the same use conditions as proposed for very low
temperature refrigeration equipment; non-mechanical heat transfer
equipment; retail food refrigeration, stand-alone equipment only;
household refrigerators, freezers, and combination refrigerator/
freezers; and vending machines.
    For room AC units, EPA is retaining the same use conditions as
proposed, with one exception. For portable AC units, EPA is not
applying the proposed charge limits for PTAC, PTHP, and other floor
mounted AC units, which are set forth in Table D. New Table E
establishes charge limits for portable AC units, consistent with the
requirements in Appendix F of UL 484, 8th Edition. This change allows
larger charge sizes for small portable units than in the proposed rule
and limits the charge size to no more than 2.45 kg of HFC-32, 300 g of
propane, or 330 g of R-441A. Proposed Table D was based on a different
section of Appendix F of UL 484, 8th Edition. EPA is making this change
because we agree with commenters that the final rule should incorporate
specific provisions for charge limits for portable units in UL 484,
which is the standard that is the basis of EPA's other charge limits,
as well.
    This final rule exempts the four hydrocarbon refrigerants for the
end-uses addressed in the proposed rule from the venting prohibition
under Section 608. HFC-32 remains prohibited from being knowingly
vented or otherwise knowingly released or disposed of by any person
maintaining, servicing, repairing, or disposing appliances containing
HFC-32.

VI. What are EPA's responses to public comments?

A. EPA's Acceptability Determinations

1. R-441A
    Comment: The Environmental Investigation Agency-U.S. (EIA), an
environmental organization, and A.S. Trust & Holdings, the submitter
for R-441A, supported the listing of R-441A as an acceptable substitute
in new stand-alone retail food refrigeration equipment, residential and
light commercial AC, and vending machines. EIA noted the climate
benefits, improved energy efficiency, and reduced flammability for this
refrigerant.
    Response: EPA agrees and thanks the commenters for their support of
this listing decision. We are taking final action in this rule to list
R-441A as acceptable subject to use conditions for use in new retail
food refrigerators and freezers (stand-alone units only); new
residential and light commercial room AC units; and vending machines.
    Comment: A.S. Trust & Holdings requested clarification as to
whether EPA is approving the SNAP applications (i.e., submissions) for
R-441A in household window AC units, vending machines, new commercial
refrigerators, commercial freezers, and stand-alone refrigerated
display cases, and new residential split[hyphen]system AC units,
residential heat pumps, and portable (floor) room air conditioners.
    Response: This final rule lists R-441A as acceptable, subject to
use conditions, for use in (1) residential and light commercial room AC
units, (2) vending machines, and (3) stand-alone retail food
refrigeration equipment, including refrigerators, freezers, and
refrigerated display cases. These correspond to the submissions for R-
441A for household window AC units, vending machines, new commercial
refrigerators, commercial freezers, and stand-alone refrigerated
display cases, and the portable room air conditioners portion of the
submission for new residential split-system AC units, residential heat
pumps, and portable room air conditioners. EPA is reviewing R-441A
separately for new residential and light commercial split-system AC
units and heat pumps, and so is not in this action listing R441A as
acceptable in these uses at this time.
2. Ethane
    Comment: EIA supported the listing of ethane as acceptable subject
to use conditions for use in very low temperature refrigeration and
non-mechanical heat transfer, and indicated that equipment using ethane
is available that will reduce impacts on climate and cut energy use.
    Response: EPA appreciates the support for listing ethane as
acceptable subject to use conditions in very low temperature
refrigeration and non-mechanical heat transfer.
    Comment: Hoshizaki America, a manufacturer of commercial
refrigeration equipment, questioned the test methods used to evaluate
ethane's flammability and fire safety.
    Response: The commenter provided no support for why they believed
this was necessary or what, if anything else, they question in the test
methods used to evaluate ethane. EPA evaluated flammability risks in
the risk screen included in the docket (Docket ID EPA-HQ-OAR-2014-0748-
0004). This evaluation followed the standard approach for evaluating
health and environmental risks that the SNAP program has used over its
20-year history. The results found worst-case leaks of ethane to result
in concentrations far below the LFL of 30,000 ppmv, showing a lack of
flammability risk. We note that a use condition requires that the
ethane-containing equipment meet the requirements of Supplement SB to
the 10th edition of UL Standard 471 and this use condition will ensure
ethane will be tested and will meet specific safety testing
requirements.
3. Isobutane
    Comment: EIA and a private citizen supported EPA's proposal to list
isobutane as acceptable subject to use conditions for the proposed end-
uses

and noted that it is already available and in use in the United States
and global markets in vending machines and in stand-alone retail food
refrigeration equipment. Hoshizaki America questioned the listing of
isobutane and does not agree that it should be listed as acceptable
without proper safety analysis.
    Response: EPA appreciates the support for listing isobutane as
acceptable subject to use conditions in vending machines and stand-
alone retail food refrigeration equipment. EPA evaluated flammability
risks in the risk screens included in the docket (Docket ID EPA-HQ-OAR-
2014-0748-0013 and -0021). The commenter that suggested isobutane
should not be listed provided no support for their statement and did
not explain what they meant by ``proper safety analysis.'' EPA's
evaluations followed the standard approach for evaluating health and
environmental risks that the SNAP program has used over its 20-year
history. The results found leaks of isobutane in stand-alone retail
food refrigeration equipment and vending machines to result in
concentrations far below the LFL of 30,000 ppmv, showing a lack of
flammability risk. We note that a use condition requires that retail
food refrigeration equipment using isobutane meet the requirements of
Supplement SB to the 10th edition of UL Standard 471 and that vending
machines using isobutane meet the requirements of Supplement SA to the
7th edition of UL Standard 541. This use condition will ensure
isobutane is further tested in equipment and will meet specific safety
testing requirements.
4. HFC-32
    Comment: A.S. Trust & Holdings; ComStar, a distributor of R-441A
and other chemicals, and several private citizens expressed concerns
with the listing of HFC-32 as an acceptable substitute in room AC units
due to its toxicity, flammability, and high GWP relative to hydrocarbon
refrigerants. These commenters said that HFC-32's higher GWP, in
combination with its flammability and other characteristics, is reason
for not finding this substitute acceptable. Most of these commenters
were specifically concerned, due to the GWP and toxicity of HFC-32,
that EPA might exempt HFC-32 from the venting prohibition. EIA and
Daikin, the submitter of HFC-32, supported listing HFC-32 as acceptable
subject to use conditions.
    Response: EPA appreciates the support from the commenters who
support listing HFC-32 as acceptable subject to use conditions for use
in room AC units.
    EPA disagrees with the commenters who suggest that the toxicity,
flammability and GWP of HFC-32 indicate it should not be listed as
acceptable, subject to use conditions, for use in room AC units. The
GWP of HFC-32 (675) is two-thirds less than that of the most commonly
used alternative for this type of equipment, R-410A (approximately
2,090) and also significantly lower than that of HCFC-22 (1,810) and R-
407C (approximately 1,770). The only currently acceptable alternatives
in this end-use with lower GWP include ammonia absorption and the non-
vapor compression technologies evaporative cooling and desiccant
cooling. However, there are technical limits on the effective use of
the non-vapor compression technologies in different climates, and
ammonia has a higher toxicity that HFC-32 and the other alternatives.
HFC-32 also has a higher GWP than two other substitutes being listed in
this end-use in this final rule--propane (GWP of 3) and R-441A (GWP of
less than 5). However, it is considerably less flammable than either
propane or R-441A. For example, HFC-32 has an LFL of 13.8% and a
burning velocity of 6.7 cm/s compared to an LFL of 2.1% and a burning
velocity of 46 cm/s for propane and an LFL of 2.05% and a burning
velocity of 47.6 cm/s for R-441A (Daikin, 2011; A.S. Trust & Holdings,
2012). EPA's risk screen on the use of HFC-32 in residential and light
commercial AC is available in the docket for this rulemaking (Docket ID
EPA-HQ-OAR-2014-0748-0005). This risk screen indicates that HFC-32's
LFL is not reached where the charge size is consistent with the use
conditions, so we do not expect a significant risk of fire.
    The commenters did not provide any information concerning why they
believed that HFC-32 should be listed as unacceptable based on its
toxicity; the commenters merely provided general information such as
Material Data Safety Sheets (MSDSs) without giving analysis specific to
HFC-32. The potential health effects listed in the MSDSs provided by
the commenters, such as freeze burns, anesthetic effects, and asphyxia,
are common to many refrigerants already in the same end-use, such as
HCFC-22, R-410A, or HFC-134a. Further, these health effects apply to
both HFC-32 and to the two hydrocarbon refrigerant substitutes that we
are also listing in this action as acceptable, subject to use
conditions, in this end-use, and the commenters did not raise concerns
for the health effects for those substitutes. EPA's risk screen
evaluates exposure and toxicity risks. In the End-Use Exposure
Assessment the modeled 15-minute and 30-minute TWA exposures for
consumers were well below the relevant short-term limit, the
cardiotoxic NOAEL for HFC-32, for all charge sizes. Based on the
Occupational Risk Assessment, occupational exposure to HFC-32 is
anticipated to be significantly below the STEL during servicing and
installation.
    In addition, as discussed below in section VI.G, ``Venting
prohibition,'' EPA did not propose, nor is it finalizing, an exemption
to the venting prohibition for HFC-32.
5. Propane
    Comment: EIA supported listing propane for use in all of EPA's
proposed end-uses (household refrigerators and freezers, vending
machines, and room air conditioners), since hydrocarbons are already
being used successfully in these types of equipment around the world. A
private citizen agreed with the listing of propane specifically for AC
units. Hozishaki America disagreed with the proposed listing of propane
without proper safety analysis.
    Response: EPA appreciates the comments supporting our decision to
list propane as acceptable subject to use conditions in the proposed
end-uses and agrees that hydrocarbons are already being used safely and
successfully in such types of equipment around the world.
    The commenter opposing listing of propane provided no support for
their statements and did not explain what they meant by ``proper safety
analysis.'' EPA's evaluations followed the standard approach for
evaluating health and environmental risks that the SNAP program has
used over its 20-year history. EPA performed risk screens on the use of
propane in household refrigerators and freezers, vending machines, and
room air conditioners which are available in the docket for this
rulemaking (Docket IDs EPA-HQ-OAR-2013-0748-0006, -0007, and -0008).
EPA's vending machine risk screen indicates that propane's LFL is not
reached in the typical scenario, and for room air conditioners and
household refrigerators and freezers, worst-case concentrations would
be well below propane's LFL, showing a lack of flammability risk. We
note that EPA is including a use condition that requires that household
refrigerators and freezers using propane meet the requirements of
Supplement SA to the 10th edition of UL Standard 250, that vending
machines using propane meet the requirements of Supplement SA to the
7th edition of UL Standard 541, and that

room air conditioners meet the requirements of Supplement A and
Appendices B through F of the 8th edition of UL Standard 484.\20\
---------------------------------------------------------------------------

    \20\ Similarly, EPA previously listed propane as acceptable,
subject to use conditions, in stand-alone retail food refrigeration
equipment, including a condition requiring that such equipment meet
the requirements of Supplement SB to the 10th edition of UL Standard
471. December 20, 2011; 76 FR 78832.
---------------------------------------------------------------------------

    Comment: Some commenters suggested that propane should be added to
the list of acceptable substitutes for the very low temperature
refrigeration end-use, particularly since it could be used with the
same UL 471 Standard as for commercial refrigeration equipment.
    Response: EPA did not receive a submission and thus has not
evaluated propane for the very low temperature refrigeration end-use.
EPA may consider it in a future rulemaking action.

B. Environmental and Public Health Impacts

1. GWP and Direct Climate Impacts
    Comment: The Alliance for Responsible Atmospheric Policy (the
Alliance), California's Air Resources Board (CARB), EIA, the Institute
of Scrap Recycling Industries (ISRI), and private citizens stated that
the proposed list of substitutes is an important step towards
mitigating the industry's environmental impact, specifically by
broadening availability of substitutes that would reduce GHG emissions
from the refrigeration and AC sector. CARB estimates that if the
proposed low-GWP refrigerants replace the high-GWP HFCs in the
identified end-use sectors, nationwide annual emissions of GHGs would
be reduced by between 9 and 11 million metric tons of carbon dioxide
equivalents (MMTCO2eq). CARB also stated that while the
reductions are a modest three percent decrease from current fluorinated
gas emissions, they believe the proposal is an important step in
mitigating the anticipated growth in emissions of HFCs.
    Response: EPA agrees that listing these five substitutes as
acceptable subject to use conditions in the specified end-uses is an
important step towards mitigating GHG emissions and the anticipated
growth in emissions of HFCs. We thank the commenter for the calculated
estimate of the potential environmental benefits associated with this
rule. We do not know if the market penetration for these newly-listed
alternatives will align with the assumptions used by CARB in developing
their estimates. However, we agree that the entrance of these
alternatives into the market and the decrease in use of higher GWP
alternatives will mitigate climate impacts from the end-uses addressed
in this rule.
2. Energy Efficiency and Indirect Climate Impacts
    Comment: CARB and EIA stated that the use of low-GWP hydrocarbon
refrigerants also indirectly reduces GHG emissions through decreased
energy use. In contrast, Master-Bilt Products, a manufacturer of
commercial refrigeration equipment, said that some of the proposed
alternatives have poor energy efficiency.
    Response: EPA agrees with CARB and EIA that, based on the available
information, the hydrocarbon refrigerants may decrease energy use and
thereby reduce GHG emissions indirectly. Each submission provided
information showing reduced energy consumption when using the
alternative refrigerants listed in this rule (Daikin, 2011; A.S. Trust
& Holdings, 2012; A/S Vestfrost, 2012; CHEAA, 2013). However, we note
that the specific energy benefits will depend on a number of factors
other than the refrigerant, such as the design of the equipment and
efforts made to fine-tune the equipment once it is installed. Master-
Bilt did not submit any specific information regarding energy
efficiency and EPA is not aware of information supporting a claim that
any of the refrigerants being listed have poor energy efficiency.
3. Ozone Depletion
    Comment: A private citizen stated that ``hydrofluorocarbon
refrigerants and CHFC [sic] refrigerants all have significant,
demonstrated negative impacts on our atmospheric ozone, while
hydrocarbons have no effect on stratospheric ozone depletion.'' The
commenter also stated that ``[i]t is accepted fact that these synthetic
fluorinated gases including HFC-32 rapidly accumulate in the atmosphere
destroying ozone by breaking molecular bonds of O3'' and
requested that EPA remove HFC-32 from the rule.
    Response: The role of HCFCs in ozone depletion is well-documented
(WMO, 2010) and these substances are in the process of being phased out
of production and consumption globally in steps. EPA agrees that
hydrocarbons do not contribute to stratospheric ozone depletion.
However, we disagree with the commenter's statement that HFC
refrigerants have significant, demonstrated negative impact on
atmospheric ozone or that they break molecular bonds of ozone. On the
contrary, HFCs have long been considered to have a negligible impact on
stratospheric ozone depletion (Ravishankara et al, 1994; \21\ WMO,
2010). Thus, EPA considers the impact of HFCs on the ozone layer to be
comparable to those of hydrocarbons.
---------------------------------------------------------------------------

    \21\ 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.
---------------------------------------------------------------------------

4. Local Air Quality Impacts
    Comment: Regarding the air quality modeling using CMAQ, A.S. Trust
& Holdings stated that that the assumption of rapid transition to all
hydrocarbon refrigerants (in Scenarios 1, 2, and 3) is not a viable
assumption, and disregards simple market realities. CARB referred to
Scenarios 1 through 3 as upper-bound maximums that are not expected to
occur.
    Response: In Scenarios 1, 2, and 3 of the air quality analysis
(ICF, 2014a), isobutane or propylene were assumed to be the only
refrigerant used, respectively, in (1) all refrigeration and air
conditioning uses, (2) all refrigeration and air conditioning uses
except for MVAC, or (3) all refrigeration and air conditioning uses
except for MVAC and large commercial chillers. EPA agrees that these
scenarios are not likely to occur. These scenarios were not intended to
project what is likely to happen in the market, but rather, to provide
screening estimates to see if there would be some level of refrigerant
emissions that could result in unacceptably high increases in ground-
level ozone. The modeling indicated that widespread use of isobutane,
propane, R-441A, and other saturated hydrocarbon refrigerants are not
likely to result in significant increases in ground-level ozone
concentrations. In contrast, the screening estimates in Scenarios 1, 2,
and 3 indicated that there could be significant increases in ground-
level ozone concentrations if use (and emissions) of propylene were
widespread. Thus, further analysis of potential air quality impacts
based on likely use of propylene in the market may be needed for
evaluating propylene or refrigerants containing propylene in any future
action in which EPA considers listing propylene for these end-uses.
    Comment: A.S. Trust & Holdings commented that the air quality
modeling focuses on only one year (2005) of meteorological data. The
commenter stated it is standard practice in ambient air modeling
studies to focus on typically five years of meteorological data to
provide a more representative sample of conditions on different days

and thus reduce the uncertainties in the analysis.
    Response: It is standard practice to use five years of
meteorological data in regulatory analyses where the assessment is for
a single facility or small group of facilities seeking an air quality
permit, such as a permit for prevention of significant deterioration,
authority to construct, or air contaminant discharge. However, in state
implementation plans or nationwide regulatory impact assessments where
an entire state or the continental United States is modeled, a full
ozone season or a single year of meteorology is generally considered
sufficient (EPA, 2007). In the case of the CMAQ analysis performed for
this rule, modeling was performed based upon refrigerant emissions from
the entire United States and thus, use of one year of meteorological
data was appropriate.
    Comment: A.S. Trust & Holdings noted that specific hydrocarbon
refrigerants were not separately modeled in the air quality model. This
commenter states that each refrigerant should be assessed separately by
the Agency and that it does not seem reasonable to regulate a single
refrigerant based on a whole family of refrigerants. This commenter
also stated that it is difficult to make any substantial conclusions
regarding propylene without assessing the more realistic Scenario 4.
CARB stated that Scenario 4 of the analysis is a good representation of
anticipated emissions and useful for assessing the potential ozone
impacts of the proposal. This commenter also stated that the small
estimated impact based on national modeling is consistent with its own
estimate of the magnitude of potential emission increases and the lower
ozone formation potential of the hydrocarbon refrigerants.
    Response: Scenario 4 is a scenario that analyzed potential air
quality impacts of hydrocarbon refrigerants in a set of end-uses that
would be more likely to use hydrocarbon refrigerants between now and
2030. These included end-uses for which UL currently has standards in
place, for which the SNAP program has already listed hydrocarbon
refrigerants as acceptable, subject to use conditions, or for which the
SNAP program is reviewing a submission, including those end-uses
addressed in this final rule. EPA agrees with the second commenter that
this scenario is useful for assessing the potential ozone impacts of
the proposal.
    We disagree with the first commenter that EPA should have assessed
each refrigerant separately in Scenario 4 as we did in the bounding
Scenarios 1, 2, and 3. We are listing a number of refrigerants as
acceptable, subject to use conditions, in several end-uses and we
expect that they all will be present in the market and in the
atmosphere at the same time. The interactions of the different
compounds in the atmosphere are interdependent and are not linear.
Modeling each refrigerant separately would result in a less realistic,
and for some refrigerants an unrealistically low, estimate of
environmental impacts. The current air quality analysis found that the
peak 8-hr ozone increase of 0.15 ppb for Los Angeles is about 75%
associated with the use of propylene as a refrigerant and 21% from
propane under Scenario 4 (ICF, 2014a, p. 10).
5. Trifluoroacetic Acid
    Comment: The Australian Refrigeration Association (ARA) stated that
the toxic buildup of trifluoroacetic acid (TFA) (which they claimed is
a byproduct of HFC-32 decomposition) in fragile eco-systems is not
reversible. This commenter also stated that if TFA levels are allowed
to build up until algae and plant life is destroyed, it will be too
late to prevent the collapse of the food chain and global catastrophe.
The same commenter also noted that even before catastrophic levels are
reached, crop yields and marine life will be adversely affected.
    Response: Available information indicates that TFA is not a
byproduct of the decomposition of HFC-32 (Wellington and Nielsen, 1999,
as cited in ICF, 2015a). We note that even if TFA were a minimal
byproduct of HFC-32, HFC-32 would not pose significantly greater risk
than other available substitutes because TFA is generated by some other
acceptable substitutes used in the same end-uses as in this rule.

C. Toxicity

1. Toxicity of Proposed Refrigerants
    Comment: Master-Bilt Products stated that the
non[hyphen]drop[hyphen]in alternatives available and proposed by EPA
have many negative characteristics including toxicity. The commenter
stated that as a result, much more testing is going to be required now
than was required with the switch from CFCs to HFCs. This commenter
stated that before these newly redesigned products can be sold, many
additional steps will need to take place, such as upgrading appliance
manufacturing facilities; training service technicians in using toxic
refrigerants; achieving customer acceptance of having toxic
refrigerants in their facilities, near their employees and customers,
and around their food products; an expansion in capacity of testing
companies such as UL, the Canadian Standards Association, and Intertek;
and updating building codes to allow for toxic refrigerants.
    Response: EPA recognizes that steps by industry and government such
as physical upgrades to equipment manufacturer facilities, capital
investments, technician training, third-party testing of equipment, and
revisions to building codes may be needed before manufacturers of
refrigeration equipment and their customers will be able to adopt the
refrigerants listed in this final rule. We also recognize that
finalizing this rule removes regulatory uncertainty about EPA's
requirements for use of these refrigerants in the listed end-uses,
another required step before these refrigerants will be adopted.
    Concerning toxicity of the proposed refrigerants, our risk screens
find that even a worst-case release of isobutane or R-441A from stand-
alone retail food refrigeration equipment will not result in exceeding
exposure limits such as the TLVs of 1,000 ppm for isobutane or for the
four components of R-441A or the relevant short-term exposure limits
for these compounds. Similarly, for propane in household refrigerators
and freezers, a worst-case release would not exceed exposure limits
such as the AEGL-1 of 6,900 ppm for propane. For vending machines,
propane, isobutane, and the components of R-441A do not exceed exposure
limits in the typical scenario, such as the AEGL-1 of 6,900 ppm for
propane. We found similar results for the other types of equipment in
this rule, as discussed above in Section IV.C, ``Toxicity and
asphyxiation.'' Thus, the refrigerants that we are finding acceptable
subject to use conditions present comparable toxicity risk to other
acceptable refrigerants already used in these end-uses.
    Comment: A private citizen stated that EPA should confirm there is
no health threat to society before approving this rule.
    Response: EPA has assessed risks to human health and the
environment--including the flammability and toxicity, considering
exposure to workers, consumers, and the general public of each
substitute listed in this final rule. In addition, we have evaluated
the environmental impacts, including potential increases in generation
of ground-level ozone, impacts on the ozone layer and global climate,
all of which can impact human health. Based on these assessments, we
have determined that the human health risks of the listed refrigerants
are comparable to or less than those from other

acceptable refrigerants in the same end-uses.
2. Toxicity of Decomposition Products of HFC-32
    Comment: ARA and A.S. Trust & Holdings expressed concern about the
potential for HFC-32 to decompose into hydrogen fluoride (HF), carbonyl
fluoride, and other toxic chemicals because it is a fluorocarbon
refrigerant. A.S. Trust & Holdings suggested that HFC-32 should not be
acceptable because of the toxicity of its decomposition products.
    Response: EPA disagrees that the potential for toxic decomposition
products from HFC-32, when used consistent with the established use
conditions, creates a risk more significant than the risks posed by
other available refrigerants in the same end-uses. The risks of
decomposition products from HFC-32 in room air conditioners are no
greater than that from currently used refrigerants such as HCFC-22 or
R-410A, all of which contain fluorine. Indeed, the most commonly used
acceptable alternative refrigerant for room air conditioners, R-410A,
is a blend that contains 50% HFC-32.
    It is true that hydrocarbon refrigerants do not contain fluorine
and thus do not have the potential for the same toxic byproducts such
as HF or carbonyl fluoride. However, the risk of generating HF only
exists when HFC-32 burns. Even in the worst-case scenario in our risk
screen for use of HFC-32 in room AC units, the concentration of HFC-32
would not exceed 69% of the LFL. Therefore, the flammability risks of
HFC-32, and the related potential to generate HF are extremely low.
Based on analysis of all of the relevant health and environmental
factors, EPA concluded that HFC-32 does not present a significantly
higher risk to human health or the environment than other currently or
potentially available substitutes in the room AC end-use.

D. Flammability

    Comment: Traulsen, a manufacturer of commercial refrigeration
equipment, and Hoshizaki America, believed there has been an incomplete
safety assessment for listing flammable substitutes as acceptable. The
North American Association of Food Equipment Manufacturers (NAFEM)
requested that the Agency reevaluate the safety and enforcement issues
that must be addressed before flammable refrigerants are ubiquitous in
the marketplace. Hoshizaki America requested further testing and
analysis on actual machines to provide more concrete evidence that
there is no significant risk for this use. This commenter specifically
questioned the test method used for the flammability and fire safety
for isobutane and ethane and disagreed with the listing of isobutane or
propane without proper safety analysis.
    Response: EPA agrees that flammability is an important
consideration with regard to substitutes evaluated in this rulemaking.
EPA evaluated the safety of these refrigerants prior to issuing the
proposal for this rule. EPA believes flammability risks can be
mitigated to ensure the substitutes can be used as safely as other
available substitutes in these uses. EPA also notes that more than 400
million hydrocarbon refrigerators are in use worldwide, as well as
millions of smaller residential air conditioners using hydrocarbons or
HFC-32. Reports of refrigerator ignition incidents resulting from
leaked hydrocarbons have been rare. To determine whether the
refrigerants would present flammability concerns for consumers or for
workers, including those servicing or disposing of appliances. EPA
reviewed the submitters' detailed assessments of the probability of
events that might create a fire, as well as engineering approaches to
avoid sparking from the refrigerant equipment. EPA also conducted risk
screens, available in the docket for this rulemaking, evaluating
reasonable worst-case and more typical, yet conservative, scenarios to
model the effects of the sudden release of the refrigerants. This final
rule establishes maximum charge sizes for each type of equipment, and
analysis for each of the substitutes revealed that even if the unit's
full charge were emitted within one minute, the concentration would not
reach the LFL for that refrigerant.
    The listings of ethane, HFC-32, isobutane, propane, and R-441A as
acceptable, subject to use conditions, will allow manufacturers to
develop equipment that will use these substitutes as refrigerants. It
is not necessary for EPA to pre-test the actual equipment as part of
its threshold analysis of whether refrigerants, used consistent with
the use conditions, will pose a flammability risk of concern. In
addition, we note that the use conditions required by this rule include
testing requirements in the relevant UL standards which are intended,
among other things, to ensure that any leaks will result in
concentrations well below the LFL, and that potential ignition sources
will not be able to create temperatures high enough to start a fire.
EPA believes risks can be mitigated to ensure the substitutes can be
used as safely as other available substitutes.
    EPA believes that complying with the use conditions listed in this
final action, as well as with use conditions listed in previous SNAP
rules, reduces overall risk to human health and the environment. These
use conditions will ensure the substitutes are further tested in
equipment and will meet specific safety testing requirements.
    EPA believes that (1) these evaluations have followed standard SNAP
methods and showed low risk, (2) our decisions rely on consensus-based
safety standards developed specifically to test and to assure safe use
of flammable refrigerants, and (3) the required use conditions reduce
the flammability risk associated with the listed substitutes. For these
reasons, these alternatives provide lower overall risk to human health
and the environment than other available or potentially available
alternatives in very low temperature refrigeration equipment, non-
mechanical heat transfer, retail food refrigeration equipment (stand-
alone units only), vending machines, room air conditioners and
household refrigerators and freezers. In response to the comment
requesting EPA to ``evaluate the safety and enforcement issues that
must be addressed before flammable refrigerants are ubiquitous in the
marketplace,'' we note that the commenter did not elaborate on what it
meant regarding ``enforcement issues.'' We considered compliance
concerns as we developed the proposed and final rule. For example, EPA
notes elsewhere in this final rule that placing the responsibility on
the manufacturer to design equipment that restricts the maximum
refrigerant charge based upon the cooling capacity needed provides a
better means for EPA to ensure compliance with the use conditions and
thus to ensure that the risk to human health will not be greater than
that posed by other available substitutes.
    Comment: Several commenters noted the flammability of HFC-32. A.S.
Trust & Holdings indicated surprise at the charge size allowed for HFC-
32, as provided in the proposed use conditions, given its flammability.
ARA states that HFC-32 is extremely flammable and notes the high
ignition temperature of HFC-32. ComStar believes HFC-32's flammability,
and proposed high refrigerant charges in indoor systems, are compelling
reasons to keep HFC-32 out of all indoor refrigerant applications.
    Response: As discussed above in section VI.A.4, HFC-32 is
significantly less flammable than the other

refrigerants considered in this rulemaking for use in room AC
equipment. The charge sizes are calculated using the same formulas from
UL 484 as those for propane and R-441A. The charge size is larger for
HFC-32 because it has a much higher (safer) LFL.
    Comment: Enertech Global, a manufacturer of heat pumps, noted that
one disadvantage of hydrocarbon refrigerants is their flammability.
However, the commenter believes that careful design, manufacturing, and
use can ensure ``safe operation and handling in every step of the value
chain.'' Daikin has sold approximately three million units worldwide
and indicated that it is unaware of any incidents where the refrigerant
ignited during installation, servicing, or removal of these systems.
Additionally, the commenter stated that in Sweden, more than 100,000
packaged heat pumps that use flammable refrigerants have been used in
safe operation for over two decades. Daikin noted that service
technician training materials already developed could reduce
flammability risks associated with hydrocarbon refrigerants.
    Response: EPA agrees that the flammability risks of concern with
hydrocarbon refrigerants can be adequately managed through proper
design, controls, and use conditions. EPA also believes that service
technician training materials will help provide protection and minimize
risks associated with hydrocarbon refrigerants. The safe operating
history of millions of HFC-32 AC units and more than 100,000 packaged
heat pumps that use flammable refrigerants is encouraging.
    Comment: NAFEM, ICOR International (ICOR), Traulsen, and Hoshizaki
America expressed various other concerns regarding the flammability of
proposed substitutes in the heating, ventilation, air conditioning and
refrigeration (HVACR) industry including: the capital costs associated
with using flammable refrigerants; the need to redesign equipment; the
lack of awareness and training for service personnel and consumers; the
need for proper technician training; and industry codes and standards.
NAFEM and ICOR expressed concerns for the technicians being able to
recognize potential ignition sources.
    Response: Refrigeration and AC equipment manufacturers are not
required to use any of the flammable refrigerants listed as acceptable
subject to use conditions in this action; we expect that those who
choose to do so will make appropriate capital investments in their
facilities. For example, EPA would expect private sector investments in
safety upgrades similar to those made when we listed certain
hydrocarbon refrigerants previously for household refrigerators and
freezers and stand-alone retail food refrigeration equipment. In
addition, manufacturers would need to invest in training their staff in
safe handling of flammable refrigerants, including how to recognize
ignition sources. For example, technicians need to be aware that
standard refrigerant recovery equipment manufactured for non-flammable
refrigerants should not be used for recovering flammable refrigerants,
because even though it technically is capable of recovering many of
these hydrocarbons at similar pressure levels, such equipment may lack
adequate explosion proofing or non-sparking parts. Further, they need
to be aware that plugging or unplugging either the refrigeration and AC
equipment or electrical refrigerant recovery equipment is an ignition
source. In addition, we note that many of the use conditions, such as
the labeling and colored hoses, are for the express purpose of ensuring
that technicians are aware that the refrigerant is flammable.
    Second, EPA believes that greater awareness of the presence, risks,
and benefits of flammable refrigerants among consumers, industry code-
and standard-setting organizations, fire marshals, and first responders
will lead to a smoother, safer transition to flammable refrigerants.
EPA is working with standards setting organizations such as UL and
ASHRAE and with technician certifying organizations to improve the
level of knowledge of technicians. EPA also intends to update the test
bank for technician certification under Section 608 of the CAA, and
could include additional questions on the safe handling of flammable
refrigerants. EPA will seek additional information and guidance on how
best to incorporate this content through a separate process outside of
this rule.
    Comment: NAFEM and ICOR expressed concern about what to do when a
leak occurs and a trained technician is not present. NAFEM suggested
that EPA should consider other foreseeable conditions in which
flammable refrigerants are used, and specify precautionary measures in
situations such as a leak where no trained technician is present.
    Response: We expect that owners of this kind of equipment will
follow the manufacturer's recommendations for safe use and, for retail
food refrigeration and other commercial equipment, OSHA requirements,
as discussed in our risk screens for each refrigerant and end-use (ICF,
2014b,c,d,e,f,g,h,i,j,k). These would assist the owner in planning for
situations where there is a leak of flammable refrigerant but no
trained technician is available. For retail food refrigeration
equipment and very low temperature refrigeration equipment, such plans
could include training staff to recognize signs of leaks (e.g., odors,
sounds, reduced cooling ability, and alarm signals where there is leak
monitoring equipment) and to actively seek steps to remove or avoid
ignition sources (e.g., post signs prohibiting smoking or open flames,
avoid plugging in or unplugging electrical equipment when a leak is
suspected). For household appliances, consumers would have guidance
provided by the equipment manufacturer in the owner's manual. In
addition, we note that the use conditions provide additional safety
measures that make equipment owners, consumers, and emergency first
responders aware of the presence of a flammability risk and that
minimize the risk that refrigerant concentrations would reach flammable
or explosive levels.
    Comment: NAFEM noted that some local building and fire safety codes
still do not allow even small quantities of flammable refrigerants and
that manufacturers will be forced to maintain their current use of R-
134a and R-404A until states and municipalities update their codes.
Traulsen believed that all issues regarding codes, standards, safe
handling and venting can and should be resolved before the option to
switch to a flammable refrigerant is the only choice available to a
manufacturer or equipment purchaser.
    Response: This current rule expands rather than limits the
refrigerant choices available in each of the proposed end-uses; thus,
no one is restricted to using a flammable refrigerant in those end-
uses. There are multiple acceptable nonflammable refrigerants available
for use in these end-uses. Government and industry cooperation, such as
the task force formed to examine and work towards updating building
codes to allow use of alternative refrigerants, has begun to address
barriers to revising building codes. However, in the absence of any
flammable refrigerant being acceptable for use, government and other
code-setting bodies may not have an incentive to revise codes to
address the use of flammable refrigerants. EPA supports the concept of
a national training program for flammable refrigerants and welcomes
industry efforts to educate technicians on proper

refrigerant use and proper service and disposal practices, including
safe handling and venting.
    Comment: NAFEM is concerned the rulemaking will result in danger to
the public as flammable refrigerants are forced into certain market
applications.
    Response: This rule does not require the use of flammable
refrigerants; other, non-flammable refrigerants remain available for
use in each of the end-uses addressed in this action. Further, as
discussed in the proposed rule and elsewhere in the preamble to the
final rule, this action requires that when the listed flammable
refrigerants are used in the specific end-uses, they will be used under
specific conditions that will mitigate the flammability risks.
    Comment: Hoshizaki America requested that refrigerants used in the
commercial refrigeration sector be from the A1 group. The commenter
noted that refrigerant manufacturers are in the phase of gaining
approval of nonflammable refrigerants that have low GWPs. The commenter
claims that these refrigerants would be near drop-in replacements with
added efficiency benefits. Structural Concepts, a manufacturer of
commercial refrigeration equipment, requested EPA to approve R-448A, R-
449A, and R-450A (nonflammable refrigerant blends of HFOs and HFCs) for
the stand-alone, supermarket, and condensing unit end-uses.
    Response: There are multiple non-flammable A1 refrigerants listed
as acceptable for commercial refrigeration (retail food refrigeration
and vending machines), including CO2 and, as mentioned by
the commenter, R-450A, a non-flammable refrigerant blend that performs
very similarly to HFC-134a but with a lower GWP. As of the writing of
this final rule, EPA was still reviewing submissions for R-448A and R-
449A.
    Comment: Hoshizaki America noted that stand-alone refrigeration
equipment is well-known for having low probability of field leaks as
leaks in such equipment would prevent the equipment from maintaining
safe temperature for food. Due to low probability of leaks, the
commenter believes the evaluation of commercial refrigeration products
should be considered separate from other fields which exhibit larger
leakage to the atmosphere.
    Response: EPA agrees that stand-alone refrigeration equipment is
less likely to leak than other types of refrigeration equipment, such
as remote systems. This final rule lists a number of flammable
refrigerants acceptable, subject to use conditions, for use in stand-
alone refrigeration equipment such as stand-alone retail food
refrigeration equipment, very low temperature refrigeration equipment,
and household refrigerators, freezers, and combination refrigerator/
freezers. We note that for purposes of our review, we consider each
end-use separately.

E. Use Conditions

1. New Equipment Only; Not Intended for Use a Retrofit Alternative
    Comment: Traulsen, ISRI, and Hudson Technologies, a refrigerant
reclaimer, supported limiting the use of the substitutes to new
equipment.
    Response: EPA appreciates the support for our proposal to establish
use conditions to limit the use of the substitutes to new equipment
only and agrees with the commenters. EPA is including this use
condition in this final action.
2. Compliance With UL Standards
    Comment: AHRI, DuPont, and GE Appliances stated that the UL 484
Standard (for room AC units) is being revised to match the fourth
edition of IEC 60335-2-40, and that these revisions will likely include
a reduced allowable charge level for flammable refrigerants. According
to the commenters, this reduction was determined to be necessary for
safe use by a group of U.S. experts. The new limit is determined by the
equation ``Charge limit = 3 m\3\ x LFL, where LFL is the lower
flammable limit in kg/m\3\ for the refrigerant used.'' The commenters
noted that the charge level is small enough that restriction based on
room size is not necessary. As such, the commenters recommended that
EPA modify the methodology used to determine maximum charge level and
revise the 3rd paragraph of use conditions as follows:
    ``The charge size for the entire air conditioner must not exceed
the maximum refrigerant mass determined according to Appendix F of UL
484, 8th edition for the room size where the air conditioner is used.
The charge size for these three refrigerants must in no case exceed 918
g (32.4 oz or 2.02 lb) of HFC-32; 114 g (4.0 oz or 0.25 lbs) of
propane; or 123 g (4.3 oz or 0.27 lb) of R-441A..'' [The previous
sentence is in place of the proposed statements, ``The charge size for
these three refrigerants must in no case exceed 7960 g (280.8 oz or
17.55 lb) of HFC-32; 1000 g (35.3 oz or 2.21 lb) of propane; or 1000 g
(35.3 oz or 2.21 lb) of R-441A. The manufacturer must design a charge
size for the entire air conditioner that does not exceed the amount
specified for the unit's cooling capacity, as specified in Table A, B,
C, or D of this appendix.''].
    The commenters note that they expect the next revision to UL 484 to
be published by the end of 2014 or early 2015.
    Response: EPA understands that the consensus-based standards that
are the basis of the use conditions in the proposed rule are under
review and may change in the future. This is true for all standards
controlled by an active organization such as UL. EPA does not believe
that it would be appropriate to adopt use conditions to reflect
standards that are not yet final and may still be subject to change.
EPA believes the consensus-based standards it relied upon are
protective of human health, rest upon sound science and reflect the
currently used and accepted guidelines in the appliance industry. Our
risk screens found that equipment that met EPA's proposed charge limits
based on the current, 8th Edition of UL 484 did not exceed the LFL or
exposure limits for each of the three refrigerants proposed for use in
room AC units, even in relatively small spaces. If UL 484 is revised in
the future, or if other information becomes available that would
support a change in charge size limits, particularly to address
specific risks, EPA remains open to revising the charge size use
condition and/or the specific edition of the UL standard, whether in
response to a petition or in an action initiated by EPA.
    Furthermore, the commenters did not provide any technical support
for the changes they anticipate will be made to the UL 484 Standard,
nor do they provide information demonstrating that the charge sizes we
proposed present unacceptable risks. We also note that while the
commenters suggest that the charge size they anticipate will be
included in a revision to the UL 484 Standard will be small enough that
no restrictions based on room size would be needed, our understanding
is that the current UL 484 standard includes formulas for charge limits
based upon a peer-reviewed study (Kataoka et al., 2000) and the IEC
60335-2-40 Standard (EPA, 2015).
    By relying on the existing UL standard, EPA remains consistent with
our approach in listing other flammable refrigerants acceptable,
subject to use conditions, including charge size limits (76 FR 78832;
December 20, 2011) as set forth in the applicable UL standards at the
time of our final listing action.
    We believe that reliance on current standards, developed with a
focus on U.S. products and applications, are more appropriate than
potential future standards that have not yet been

adopted. We believe reliance on existing standards provides certainty
for manufacturers, while reducing the flammability risks that may exist
due to use of the flammable refrigerants listed in this action. While
charge size limits may change in the future, EPA cannot anticipate the
timing or extent of such changes.
    Should a manufacturer seek UL approval of their equipment in a
possible future where the standard has changed, they would need to meet
both the use conditions EPA has finalized today and meet the presumably
more restrictive requirements of the UL standard applicable at the time
they are seeking UL approval. We also note that should a manufacturer
choose to adopt one of the refrigerants covered by today's action, they
must decide what charge size they will design their equipment for and
may choose any charge size equal to or below the maximums set under
today's action.
    Comment: The Association of Home Appliance Manufacturers (AHAM) and
the Alliance stated that EPA should work towards a harmonized
international standard. UL noted their organization's work towards
harmonizing standards through the introduction of the UL 60335-2-40
Standard. This commenter suggested that EPA allow compliance with both
the UL 484 and the UL 60335-2-40 Standards. UL also clarified that the
UL 484 Standard will eventually be withdrawn and replaced with the UL
60335-2-40 Standard, possibly in 2020.
    Response: EPA appreciates information regarding efforts that may
result in the withdrawal of UL 484 and its being replaced by UL 60335-
2-40 perhaps by 2020. As provided in the previous response, however,
EPA believes it is appropriate to rely on the existing UL 484 Standard
in this final rule. If UL 484 is replaced with UL 60335-2-40 in the
future or is otherwise modified, EPA remains open to revising the use
condition, whether in response to a petition or in an action initiated
by EPA. Regarding the comment that the use condition allows compliance
with either UL 484 or UL 60335-2-40, we note that today there are some
differences in labeling requirements and in the specific tests to be
performed that could lead to confusion and difficulty in enforcing
requirements of two standards simultaneously. Moreover, as noted in our
previous response, EPA's consistent practice for flammable refrigerants
has been to base the use conditions on the applicable UL standard.
    Comment: Daikin notes a discrepancy between UL 484, which allows
for limited ducts used in PTAC installations, and the EPA footnote 10,
which indicates that no ducts can be used for PTACs using HFC-32. This
commenter believes that the UL 484 standard should be followed, as
ducts present no additional fire risk in systems with hermetically
sealed refrigerant loops.
    Response: EPA agrees with the commenter that UL 484 does allow for
limited ducts in PTAC installations, contrary to footnote 10 in the
preamble to the proposal. In this final action, we are clarifying by
correcting that footnote to be consistent with the 8th edition of the
UL 484 standard by removing the statement about ducts.
    Comment: Traulsen recommends that EPA consider that equipment being
manufactured specifically for markets outside the United States is
governed by the applicable standards and guidelines of those countries.
The commenter states that the proposed use conditions would restrict a
manufacturer's ability to place a product on the market in another
country. The commenter encourages the EPA to allow flexibility for
products to be sold into global markets, providing that such equipment
is clearly marked for export purposes only. For example, Traulsen
requested that equipment manufactured exclusively for export only be
subject to the charge sizes in regulations applicable to the
destination country.
    Response: Under Section 612 of the CAA and EPA's implementing
regulations in Subpart G of 40 CFR part 82, the SNAP program is
applicable to any person introducing a substitute into interstate
commerce. This applies to the introduction into interstate commerce of
any appliances produced in the United States, including appliances that
will be exported. EPA has previously responded to comments about the
applicability of the SNAP program to products destined for export. Most
recently, in a final rule issued December 20, 2011, EPA responded to a
comment concerning whether appliances manufactured for export should be
allowed to have larger charge sizes than those being sold in the United
States (and thus not have to comply with the use conditions being
established in that rule). EPA stated that:

    Under Section 612 of the Clean Air Act, the SNAP program is
applicable to any person introducing a substitute into interstate
commerce. Interstate commerce is defined in 40 CFR 82.104(n) as: The
distribution or transportation of any product between one state,
territory, possession or the District of Columbia, and another
state, territory, possession or the District of Columbia, or the
sale, use or manufacture of any product in more than one state,
territory, possession or the District of Columbia. The entry points
for which the product is introduced into interstate commerce are the
release of a product from the facility in which the product was
manufactured, the entry into a warehouse from which the domestic
manufacturer releases the product for sale or distribution, and at
the site of United States Customs clearance. This definition applies
to any appliances produced in the United States, including
appliances that will be exported. (76 FR 78846)

    The commenter has provided no new information that would cause us
to reverse our earlier decision.
    We believe that compliance with these final use conditions,
including the specified UL standards and charge sizes, does not
restrict or prohibit manufacturers from exporting to other markets. For
most of the uses addressed in this rule, international standards
regarding charge size are the same as those we are establishing in the
use conditions.
    In the case of household refrigerators and freezers, the charge
size requirement in our regulation is more stringent (57 g vs. 150 g)
than the comparable international standard. Even in this case, however,
the use condition would not restrict or prohibit the export of products
to international markets. Rather, the manufacturers could export
products so long as they complied with all of the use restrictions,
including the charge size of no more than 57 g.
3. Charge Size Limitations
    Comment: EIA stated that the propane charge limit size of 57 g for
household refrigerators and freezers, set by the UL 250 standards,
should be increased to 150 grams, matching the IEC 60335-2-24
standards. The commenter notes that this is consistent with European
policies, and corresponds to an R-22 charge size of 300-350 grams.
    Response: As discussed in our previous final rule that required a
charge size of 57 g for R-441A and isobutane in household refrigerators
and freezers, ``EPA does not have sufficient information supported by
safety testing data at this time from other commenters, industry, U.S.
national safety organizations, or non-governmental organizations to
support a charge size limit different from one based on UL 250, such as
the 150-gram limit in IEC 60335-2-24.'' (76 FR 78845; December 20,
2011). Further, our risk screen analysis of potential exposure at end-
use for a household refrigerator/freezer indicates that in a worst-case
release scenario, a charge as small as 104 g could result in consumer
exposure above the STEL of 6,900 ppm for propane (ICF, 2014h). The
commenter did not submit any technical

information showing that a charge size of 150 g could be used in this
end-use without posing a significantly greater risk than other
available substitutes.
    Comment: UL believes that the lowered charge limits suggested by
the Joint Task Group (JTG) and Standards Technical Panels (STP) from
the 2011 Flammable Refrigerant Stakeholder Forum are especially
important for safety in room AC units, given that many room air
conditioners are removed from wall or window sleeves annually and
placed in storage, potentially increasing the risk of ignition in the
presence of flammable refrigerants.
    Response: EPA recognizes that many room air conditioners are
removed and placed in storage, for example when changing from warmer,
summer temperatures to colder, winter temperatures. This fact was
understood when the current charge limits set in UL 484 were developed.
While we recognize that an annual removal/replacement cycle could
increase the risk that refrigerants in such products might leak, we are
not aware of, nor did we receive comments providing a safety assessment
that would give an analytical basis on which to set charge size limits
different than those proposed. EPA does not believe that the commenter
fully justified the need or reason to change our proposed charge size
limit, which are based on the existing UL 484 Standard (8th edition),
to a charge size recommended by the JTG and STP, but not yet formally
adopted.
    Comment: Enertech Global believes that the proposed charge
limitations for propane found in Table 4, Maximum Design Charge Sizes
for Packaged Terminal AC Units and Heat Pumps and Portable AC Units,
are set too low and that it is not feasible to manufacture a unit with
the specified cooling capacity using the small refrigerant charges
listed. De' Longhi, another manufacturer of AC equipment, stated that
under relevant standards, there is a specific formula with higher
charges allowed for portable AC units in IEC 60335-2-40 Clause gg.8 and
UL 484 Appendix F Clause F.1.7 (e.g., 300 g for a capacity of 12,000
BTU/hr instead of 160 g under the proposal). This commenter states that
there are additional safety requirements specifically for portable AC
units that allow for larger charge sizes.
    Response: EPA is establishing a use condition that sets charge size
limits based on the need to ensure the risk to human health and the
environment posed by propane is not significantly greater than that for
other available substitutes, not on the feasibility of manufacturing
specific products. The charge sizes in the proposed and final rule are
based upon the UL 484 Standard, 8th Edition. For portable AC units, the
use condition establishing charge size relies on the provisions of UL
484 Appendix F Clauses F.1.7-F.1.14. Clause F.1.7 allows non-fixed,
factory-sealed units, which for purposes of this rule we define solely
as portable room AC units, to follow the formula:

Mmax = 0.25 x A x LFL x 2.2

Where,
Mmax is the maximum charge size in kg,
A is the room area in m\2\ and
LFL is the lower flammability limit in kg/m\3\.

    The formula applies only to units with a refrigerant charge M that
is less than or equal to twice the value of ``m1,'' which in
turn is defined as four cubic meters multiplied by the LFL in kg/m\3\.
    Similar to the use-conditions set forth for other room air-
conditioners, EPA is setting additional charge size limits according to
the normal rated capacity of the unit. For portable room air
conditioners, these maximum charge sizes in terms of capacity are in
Table E (also described above in Section III.C.3, ``Charge size'').
    Comment: Daikin stated that the charge limits in UL Standard 484
are sufficient to protect the safety of all involved in the use and
maintenance of relevant equipment, and that any further limitations
would cause the commenter ``to revisit EPA's justifications for any R-
32 charge size limits.'' The commenter agreed with the guidance to use
linear interpolation to determine maximum charge size if the capacity
lies between two values in EPA's tables and believes that it would not
be beneficial to add any more values to the tables. The commenter also
states that a requirement for manufacturers to match charge size to
design cooling capacity in flammable refrigerant systems would not
significantly reduce fire risk.
    Response: EPA is finalizing charge size limits for room air
conditioners as proposed, including a linear interpolation, as
supported by this commenter. EPA notes in its response to other
commenters that if and when charge sizes are updated, EPA remains open
to revising the charge size use condition, whether in response to a
petition or in an action initiated by EPA. EPA also believes that the
use condition requiring manufacturers to meet charge size limits based
on design cooling capacity may allow for more appropriate selection of
unit sizes by the end-user than the use of room area, as well as
greater enforceability.
    Comment: ComStar opposed the use of HFC-32 as a refrigerant in
indoor applications because of its proposed high charges, as well as
its toxicity, flammability, and GWP over 600. The commenter remarked
that the use of R-32 in indoor applications is counter to ``the
direction foreign governments, science, and OEMs are heading.''
    Response: Charge sizes are higher for HFC-32 under this standard
than for propane or R-441A, the other refrigerants proposed for use in
room air conditioners, because HFC-32 is far less flammable and has a
much higher LFL. Based on the safety testing available in the record
for this action, we believe that meeting a charge size that is no
higher than that provided in the use conditions, HFC-32 does not pose
significantly greater risk than other refrigerants in the room air
condition end-use. This testing addressed flammability and toxicity
risks. Moreover, HFC-32's GWP of 675 is two-thirds less than that of
the most commonly used alternative for this type of equipment, R-410A
(approximately 2,090) and also significantly lower than that of HCFC-22
(1,810) and R-407C (approximately 1,770). The only currently acceptable
alternatives in this end-use with lower GWP include ammonia absorption
and the non-vapor compression technologies evaporative cooling and
desiccant cooling. However, there are technical limits on the effective
use of the non-vapor compression technologies in different climates,
and ammonia has a higher toxicity that HFC-32 and the other
alternatives.
    Regarding the direction of foreign governments, we note that EPA is
setting requirements for appliances that enter interstate commerce in
the United States. The European Union (EU) regulations addressing
fluorinated substances allow use of refrigerants with a GWP of up to
750 for split residential AC, which includes the potential for HFC-32
to be used, while their regulations do not allow for refrigerants with
a GWP higher than 150 in ``moveable room air-conditioning appliances,''
which would exclude HFC-32 for that type of equipment. The EU
regulations also include a phasedown schedule with a plateau and not a
complete phaseout of HFCs. Thus, it does not appear that the EU F-gas
regulations are moving in a direction away from allowing for HFC-32 for
all end-uses. EPA based charge size limits on UL 484, which is the same
approach used for other refrigerants which this commenter supports.
    The listing of HFC-32 acceptable subject to use conditions
contained in

today's action does not prevent OEMs from choosing a different
refrigerant; it only provides an option for those who wish to pursue
it. Further, EPA notes that the submission under SNAP for the use of
HFC-32 came from an OEM that supports its use in United States as well
as in other markets around the world.
    Comment: A.S. Trust & Holdings stated that they are surprised by
the high charge amount for HFC-32, given its flammability. Further, the
commenter provided charge information for R-443A and has noted that the
LFL of R-441A is nearly identical to that of R-443A, such that the
maximum allowable charge per room volume for a portable AC unit charge
with R-441A could be determined via the similar chart for R-443A.
    Response: EPA set the charge size limits for HFC-32 using the same
approach as used for the other refrigerants listed as acceptable
subject to use conditions for self-contained room air conditioners.
Charge sizes are higher for HFC-32 under the UL 484 standard than for
propane or R-441A, the other refrigerants proposed as acceptable for
use in room air conditioners, because HFC-32 is far less flammable and
has a much higher LFL. As discussed above, we have set the charge sizes
for R-441A based upon the formulas in UL 484, including new charge size
limits for portable AC units.
    Comment: Traulsen stated it agrees with the necessity of charge
sizes, but requested that these limits be continually revisited and
updated as applicable standards update safety information.
    Response: EPA notes that charge size limits within consensus-based
standards are under constant revision and updating. In fact, several
commenters supplied information about one or more revisions that are
under consideration. If and when charge sizes are updated, EPA remains
open to revising the charge size use condition, whether in response to
a petition or in an action initiated by EPA.
    Comment: Panasonic Healthcare, a manufacturer of very low
temperature refrigeration equipment, stated that the maximum charge
size for propane in commercial refrigeration applications should be 150
g per circuit, matching the level described for ethane in commercial
refrigerators and freezers, given that both are subject to the 10th
edition of UL 471.
    Response: In a previous rulemaking (76 FR 78832; December 20,
2011), EPA found propane acceptable subject to use conditions,
including a charge size limit of 150 g as specified in the 10th edition
of UL 471, in stand-alone retail food refrigeration equipment. EPA did
not receive a SNAP submission, and did not address in its proposed
rulemaking, the use of propane in very low temperature refrigeration.
    Comment: Master-Bilt Products stated that the 150 g charge limit
will allow for only 25% of its self-contained models to be used, as the
BTU/hr capacity required for larger models cannot be achieved at the
charge limit. The commenter also noted that it is unclear if multiple
systems can use the 150 g charge in one larger model.
    Response: EPA recognizes that a charge size limit, regardless of
what it is, could restrict the types of products that could be
manufactured with these refrigerants. Manufacturers may choose to
pursue these refrigerants for smaller BTU/hr capacity equipment and/or
investigate technologies that could extend the use of these
refrigerants to larger equipment while still meeting the 150 g use
condition. Consistent with previous actions, (76 FR 78832; December 20,
2011), the charge size limit applies to any sealed refrigeration system
in a product, and some products could employ two or more separate
sealed systems. EPA notes that if more than one sealed system is
employed, each must meet the charge size limit (i.e., 150 g each).
Having multiple sealed systems is of less concern than having a single
system with the same combined charge since the probability of two
sealed systems leaking simultaneously is lower than that of any one
system leaking. See 76 FR at 78845.
4. Color-Coded Hoses and Piping
    Comment: Daikin stated that HFC-32 is unique in being a ``lower
flammability'' refrigerant in the A2L category of the ASHRAE standard
and in being subject to venting restrictions, as opposed to the other
four substitutes that are ``higher flammability'' refrigerants in the
A3 category of the ASHRAE standard and that are to be exempted from the
venting restriction. In light of this, the commenter requested the use
of ANSI Safety Yellow PMS #109 for HFC-32 and continued use of red PMS
#185 for the other four substitutes. The commenter asserted that this
change will avoid confusion and inadvertent venting of HFC-32 by
installers and technicians.
    Response: Red coloring is understood to represent ``hot,''
``stop,'' or ``danger,'' and red coloring will provide technicians,
consumers, and emergency responders with an unambiguous signal that a
potential hazard is present. The latter two groups in particular are
more likely to be familiar with the meaning of red coloring and to
consider that color as a warning of danger. Yellow coloring could
communicate the flammability risks less clearly than red, and use of
two colors for different flammable refrigerants may both increase
confusion and dilute the effectiveness of the coloring as a warning.
EPA is finalizing a requirement to use red PMS #185 coloring on hoses
and tubing for equipment charged with HFC-32, R-441A, or propane in
room air conditioners. This is the same color specified in AHRI
Guideline N-2012, ``Assignment of Refrigerant Container Colors,'' to
identify containers of flammable refrigerant, such as propane,
isobutane, and R-441A (AHRI, 2012). We believe the purpose of the
coloring is to communicate the presence of a flammable refrigerant and
that this purpose can be accomplished best by using the same coloring
for HFC-32, propane, isobutane, and R-441A. EPA may consider whether
there should be added markings to communicate when a refrigerant may or
may not be vented in a future rule.
    Comment: Traulsen agreed that the colored hoses and piping may
increase attention.
    Response: EPA agrees with the commenter.
    Comment: Traulsen stated that the benefits of colored hoses and
piping have not been proven relative to the cost of burden in any
studies. Additionally, the commenter noted that if a product is
serviced, there is a risk that the sleeve or cap may not be properly
replaced unless EPA establishes a ``safe practice'' for servicers.
    Response: EPA does not believe that this requirement will impose a
burdensome additional cost. The only commenter to raise this point did
not provide any information about what such costs might be and why the
commenter thought they would be burdensome. EPA believes that the use
of a sleeve or cap is consistent with the use condition as long as the
requirements of the use condition (use of PMS #185, location, and
dimension) are met. However, in order to remain in compliance with the
use condition, a technician who removes a sleeve during servicing is
required to replace the sleeve on the serviced tube.
    The purpose of the colored hoses and tubing in this case is to
inform service technicians, consumers and emergency responders that a
flammable refrigerant is in use and to enable technicians to take
additional precautions (e.g., reducing the use of sparking equipment)
as appropriate to avert accidents when servicing the appliance. Color
coding is particularly useful in the event that labels are no longer
legible. The air-conditioning and refrigeration industry

currently uses distinguishing colors to identify containers of
different refrigerants. Likewise, distinguishing coloring is used
elsewhere to indicate an unusual and potentially dangerous situation,
such as the use of orange-insulated wires in hybrid electric vehicles.
    The labeling requirement discussed in Section III.C.5 will
complement the color-coding requirements by providing a more precise
warning of the potential hazards and necessary precautions. Further, it
is possible that labels, particularly those on the outside of the
appliance, may be removed or fall off or become illegible over time;
adding red coloring on tubing inside the appliance provides additional
assurance that technicians will be aware that a flammable refrigerant
is present.
5. Labeling
    Comment: Traulsen, ISRI, Daikin, and Hudson Technologies expressed
support for the requirement for warning labels. Traulsen stated that
because equipment is designed for multiple markets with different
languages, the warning symbols and colors should be sufficient to allow
for \1/8\-inch lettering in the UL standards as opposed to the \1/4\-
inch proposed.
    Response: EPA appreciates the support for the requirement for
warning labels. Regarding the lettering size, EPA continues to believe
that it would be difficult to read warning labels with the smaller \1/
8\-inch lettering stipulated by UL 250 and UL 471 and is finalizing the
\1/4\-inch minimum height proposed, making it easier for technicians,
consumers, retail store-owners, and emergency first responders to see
the warning labels. The color markings would be inside the equipment
where technicians could see them, but not consumers, retail store-
owners, or emergency first responders. The warning symbol appears in
fewer locations than the warning labels and provides less information,
and thus is not a substitute for an easily readable set of warning
statements.
6. Unique Service Fittings
    Comment: The Alliance, Hudson Technologies, and ISRI, supported the
use of unique service fittings for flammable refrigerants, in response
to EPA's proposal to recommend, but not require, such fittings. Hudson
Technologies and ISRI stated that EPA should require unique service
fittings. Traulsen agreed with the decision to not require service
ports for self-contained equipment given the increased risk of system
leaks. The commenter acknowledged that requiring a different service
port for non-flammable refrigerants may establish a ``safe practice,''
but noted that it does not guarantee servicing companies will safely
work on installed equipment. The Alliance stated that separate fittings
for flammable refrigerants, in addition to color coded hosing and
piping, will be an effective warning system to alert technicians to the
presence of flammable substances. ISRI stated that these fittings will
be useful for the future recovery of refrigerants by recyclers.
    Response: EPA agrees with commenters that service ports and unique
fittings should not be required for self-contained equipment given the
increased risk of system leaks. EPA also agrees that separate fittings
for flammable refrigerants, in addition to color-coded hosing and
piping and warning labels, can be an effective warning system to alert
technicians to the presence of flammable substances, and that these
fittings would be useful for the future recovery of refrigerants by
recyclers. We disagree with the commenters that suggested we require
unique fittings as a use condition. While there are some benefits to
unique fittings, there are also concerns. As we recognized in our
December 2011 rule, these concerns include that: Installation of
fittings at the time of manufacture is not appropriate for certain
appliance types; additional fittings present an increased leak risk;
the ease of circumventing the requirement; and inconsistency with UL
and international standards. In particular because the types of
equipment in this rule are self-contained and have a hermetically-
sealed refrigerant circuit, installing fittings at manufacture would
increase the risk of leakage and thus increase potential of a fire.
Also, the UL standards that are incorporated by reference in the use
conditions do not allow for equipment to be constructed with an access
port (which would be where unique servicing fittings would be installed
on the equipment). Therefore, this final rule continues to recommend,
but not require, only if someone chooses to add an access port that
they do so with separate servicing fittings for flammable refrigerants
and that they only consider this where it is not prohibited by the
required UL standard.

F. Technician Training

    Comment: A number of commenters stated that technicians should be
properly trained in handling flammable refrigerants, with Traulsen,
NAFEM, ICOR, Hudson Technologies, and the Alliance commenting that
training should be mandatory. Daikin, the Alliance, and DuPont
expressed concern that technicians could be confused if EPA exempts
certain refrigerants from venting requirements. Hoshizaki America
commented that U.S. technicians are not properly trained in servicing
appliances with flammable refrigerants, EPA does not explain the risk
of explosion well, and that U.S. industry and consumers might not be
aware that a unit contains flammable substances. ARA includes a list of
questions about MSDSs that HVACR contractors can ask to improve safety
with any refrigerant.
    Response: While EPA appreciates the concerns raised by the
commenters, we have been exempting certain refrigerant substitutes from
the venting prohibition since 1995. EPA already exempts certain
refrigerants used from the venting prohibition including propane (in
retail food refrigeration--stand-alone units only), and isobutane and
R-441A (in household refrigerators, freezers, and combination
refrigerator/freezers). Therefore, we do not believe that continuing
with this established practice should cause confusion.
    The Agency understands that over the past 20 years there have been
numerous developments in this industry and that often training programs
are developed to familiarize technicians with these changes, including
the introduction of new refrigerants. EPA is aware of such continuing
education programs offered by vocational schools, unions, trade
associations, equipment manufacturers and other entities that provide
technicians information on a range of technology developments.
Therefore, the Agency recommends that anyone servicing appliances with
a flammable refrigerant receive appropriate training and follow
industry best practices. Given the extent of technical knowledge
available within the industry and the presence of voluntary training
programs, we believe that it is not necessary for EPA to require
training at this time in order for these newly listed refrigerants to
be used as safely as other refrigerants currently available.
    EPA is not requiring training through today's action. EPA notes
that the Agency does require technician certification under Section 608
for technicians servicing, maintaining, or repairing appliances
containing ozone-depleting refrigerants, but does not require any
specific training and the certification program is limited in its
scope, as it is not intended to replace vocational training. The goals
of the Section 608 technician certification program reflect the need to
reduce emissions during servicing,

maintenance, repair, and disposal. The complete requirements are
included at 40 CFR part 82, subpart F. Currently the regulations
require anyone who services, maintains or repairs appliances containing
an ozone-depleting refrigerant to be tested and certified. However, the
Agency is undertaking a review of the Section 608 technician
certification requirements--including whether to address flammable
refrigerant substitutes--through a separate process.

G. Venting Prohibition

    Comment: ISRI and a number of private citizens support EPA's
conclusion that venting hydrocarbons does not pose a threat to the
environment. One commenter notes that other countries allow venting of
hydrocarbons. In contrast, Hudson Technologies believes intentional
venting to the atmosphere to be poor environmental policy and that the
low GWP of hydrocarbons does not justify their exemption from venting
prohibitions.
    Response: For the reasons discussed in section III.D, ``Venting
prohibition,'' EPA agrees that venting, release, or disposal of the
following hydrocarbon refrigerant substitutes in the following end-uses
and subject to the use conditions listed in this action does not pose a
threat to the environment: (1) Isobutane and R-441A in retail food
refrigerators and freezers (stand-alone units only); (2) propane in
household refrigerators, freezers, and combination refrigerators and
freezers; (3) ethane in very low temperature refrigeration equipment
and equipment for non-mechanical heat transfer; (4) R-441A, propane,
and isobutane in vending machines; and (5) propane and R-441A in self-
contained room air conditioners for residential and light commercial
air conditioning and heat pumps. EPA's decision is based on
consideration of multiple environmental characteristics and not just
GWP. The comments do not give us sufficient reason to change our
proposed conclusion that these refrigerant substitutes in these end-
uses, subject to the required use conditions, do not pose a threat to
the environment or to change this final rule so that they would not be
exempt from the venting prohibition.
    In addition, EPA's exemption from the CAA venting prohibition of
these substances in these end-uses is consistent with how other
countries, including Australia, Japan, and those in the European Union,
regulate the venting of hydrocarbons.
    Comment: ARA and some private citizens asserted that HFC-32 has a
significant impact on the environment, with a 100-year GWP of 675,
raised concerns about its toxicity in the context of venting, and
stated that it should not be exempt from the venting prohibition.
    Response: EPA did not propose to create an exemption to the venting
prohibition for HFC-32 and is not establishing such an exemption in
this final action. Therefore, the venting prohibition under Section 608
and the implementing regulations at 40 CFR 82.154(a)(1) on knowingly
venting, releasing, or disposing of refrigerant substitutes still
applies to HFC-32 (and all other fluorinated gases), including in the
end-use for which we are taking final action today under SNAP (i.e.,
room AC units).
    Comment: Traulsen, Hoshizaki America, NAFEM and DuPont expressed
concern about the potential confusion from and safety consequences of
EPA's proposal to exempt certain substances from the venting
prohibition. DuPont states that the differential treatment of
refrigerants in such a manner could be misunderstood and could lead to
unintended venting and environmental consequences from the release of
ozone-depleting refrigerants.
    Response: EPA has evaluated the environmental and safety
considerations of venting in: (1) Isobutane and R-441A in retail food
refrigerators and freezers (stand-alone units only); (2) propane in
household refrigerators, freezers, and combination refrigerators and
freezers; (3) ethane in very low temperature refrigeration equipment
and equipment for non-mechanical heat transfer; (4) R-441A, propane,
and isobutane in vending machines; and (5) propane and R-441A in self-
contained room air conditioners for residential and light commercial
air conditioning and heat pumps. After this review, EPA has determined
the exempted releases do not pose a threat to the environment and thus
that it is appropriate to exempt these refrigerant in these specific
end-uses and subject to these use conditions from the venting
prohibition under Section 608(c) of the CAA. The comments do not
provide sufficient grounds to compel us to change that conclusion.
While EPA appreciates the concerns raised by the commenters, the agency
has been exempting certain refrigerant substitutes from the venting
prohibition since 1995. Therefore, we do not believe that continuing
with this established practice should cause confusion. Also, as
discussed above, the Agency is undertaking a review of the Section 608
technician certification requirements--including whether to address
flammable refrigerants--through a separate process.
    Comment: CARB was concerned with the potential increase in ground-
level ozone formation resulting from venting hydrocarbons, especially
in non-attainment regions in California such as the South Coast Air
Basin and the San Joaquin Valley Air Basin. CARB commented that their
own modeling results agree with the conclusion of Scenario 4 of EPA's
air quality modeling results.
    Response: EPA has assessed the possible increase in ground-level
ozone formation and believes it is appropriate to finalize the
exemption from the venting prohibition as described in this action. We
found that even if all the refrigerant in appliances in end-uses
addressed in this rule were to be emitted, there would be a worst-case
impact in the Los Angeles area of less than 0.15 ppb. Further, this
estimate is likely to be higher than the impact resulting from actual
emissions due to venting of the refrigerant substitutes listed in this
rule in the specified end-uses, because the estimate includes emissions
from a more reactive refrigerant substitute that is not listed and not
allowed to be vented under this rule. Because of the relatively low air
quality impacts of these refrigerants if they are released to the
atmosphere in limited amounts, as well as the factors discussed above,
such as their low GWP, zero ODP, and lack of aquatic effects, EPA is
concluding that these four hydrocarbon refrigerant substitutes in the
end-uses and subject to the use conditions do not pose a threat to the
environment. For more detail, see Sections III.D, IV.A and VI.B.
    Comment: Two private citizens state that hydrocarbons are non-toxic
and therefore venting of hydrocarbon refrigerants into the atmosphere
would be an acceptable practice.
    Response: While the hydrocarbons being listed as acceptable in this
rule are generally low in toxicity, they can lead to asphyxiation and
other adverse health effects in high enough concentrations. Therefore,
EPA considered exposure limits and potential exposure concentrations
when assessing the safety and the acceptability of hydrocarbons under
SNAP. This analysis found that the listed refrigerant substitutes, when
used according to the required use conditions, would not exceed the
relevant exposure limits (e.g., TLVs, STELs, or AEGLs), indicating that
toxicity is not a significant risk for the specific refrigerant
substitutes in the end-uses listed when used according to the required
use conditions. See

Sections III.D.4.ii and IV.C for more detail on EPA's toxicity
assessment of these refrigerants during servicing and disposal. Thus to
the extent that this information is relevant to EPA's determination
under Section 608(c)(2), EPA does not believe that toxicity
considerations preclude finalizing the exemption from the venting
prohibition in this action.
    Comment: Traulsen, Hoshizaki America, NAFEM, ICOR and DuPont
expressed concerns about the flammability of hydrocarbon refrigerants
and the adequacy of safety measures during venting. DuPont stated that
because of the low minimum ignition energy of hydrocarbon refrigerants,
these refrigerants are easily ignited by static electricity. This
commenter stated that venting in an uncontrolled environment could lead
to unsafe conditions. NAFEM and ICOR mentioned that use of a class B
fire extinguisher would not be sufficient to avoid an explosive
condition.
    Response: Because of safety concerns, EPA has required numerous use
conditions for appliances using flammable refrigerants as part of the
SNAP listings. A discussion of the SNAP use conditions and EPA's
assessment of safety, which considered a full release of the charge
within one minute, is available in the risk screens released with the
proposal. When it comes to servicing, the charge size limit and the
labeling requirements (e.g., visible warning statement and red coloring
on the pipes, hoses and devices which contain refrigerant) will reduce
the risk of a fire significantly. However, additional precautions are
recommended, like ensuring proper ventilation and avoiding ignition
sources during servicing.
    Concerning the risks of fire from static electricity, EPA notes
this concern about the ignition of hydrocarbon refrigerants was
discussed in the 2011 SNAP rule, in which propane was evaluated for use
in stand-alone retail food refrigeration equipment and R-441A and
isobutane were evaluated for use in household refrigerators and
freezers, and were determined to be acceptable, subject to use
conditions, under SNAP. In section ``B. Flammability'' of part IV of
that SNAP rule, titled ``What is the basis for EPA's final action?''
the Agency describes the evaluation and conclusion for approving those
hydrocarbon refrigerant substitutes for the specific end-uses under the
use conditions. The 2011 SNAP rule explains that, ``when the
concentration of a flammable refrigerant reaches or exceeds its LFL in
the presence of an ignition source (e.g., a static electricity spark
resulting from closing a door, use of a torch during servicing, or a
short circuit in wiring that controls the motor of a compressor), an
explosion or fire could occur'' (76 FR at 78837). The 2011 SNAP rule
continues by stating that, ``To determine whether the three hydrocarbon
refrigerants would present flammability concerns for service and
manufacture personnel or for consumers, EPA reviewed the submitters'
detailed assessments of the probability of events that might create a
fire, as well as engineering approaches to avoid sparking from the
refrigeration equipment. EPA also conducted risk screens, available in
the docket for [that] rulemaking, evaluating reasonable worst-case
scenarios to model the effects of the sudden release of the
refrigerants. The worst-case scenario analysis for each of the three
hydrocarbons revealed that even if the unit's full charge were emitted
within one minute, the concentration would not reach the LFL for that
hydrocarbon'' (id. at 78839). EPA's risk screens evaluating the
environmental, toxicity and flammability risks of the refrigerant
substitutes and end-uses in this action came to similar conclusions
that the LFL would not be exceeded. Thus, although end-users should
take precautions to reduce sparking from static electricity, this
concern is not sufficient to cause EPA to prohibit use of these
refrigerant substitutes or to decline to exempt these refrigerant
substitutes in the specified end-uses when used according to the
required use conditions.
    Use of a Class B fire extinguisher would not prevent a fire or
explosive condition from occurring, as the commenter suggested; but if
there is a fire, it is important to use a Class B extinguisher that is
intended for use with hydrocarbon fires, rather than a Class A
extinguisher intended for use with fires from wood, paper, or other
ordinary combustibles. The statements in the ``further information''
column for each listing, including the recommendation for having a
Class B dry powder type fire extinguisher available, are not intended
to be a comprehensive set of all precautions needed, but rather basic
guidelines or areas of consideration that users should consider as they
develop their own safety programs. The Australian Institute of
Refrigeration, Air Conditions and Heating (AIRAH) provides useful
guidance on safety precautions technicians can follow when servicing
equipment containing flammable refrigerants. This document is included
in the docket for this rule (AIRAH, 2013).
    Comment: DuPont stated that the presence of lubricants during the
venting process can potentially increase risk of ignition, and is not
sure whether EPA fully evaluated these potential risks.
    Response: EPA has evaluated this potential risk and taken it into
consideration in this action. Most lubricant will remain in the unit,
along with a small amount of hydrocarbon refrigerant substitutes.
Typical compressor oils have flashpoints over 130 [deg]C, which is well
above both ambient temperatures and the flashpoint of the hydrocarbon
refrigerant substitutes in this rule. Thus, the presence of compressor
oil should not have a significant effect on the flammability of the
refrigerant-oil mixture. Our risk screens available in the docket for
this rulemaking find that even if the full charge is lost in one
minute, the LFL of the hydrocarbon refrigerant substitute is not
reached. Having said that, the Agency recommends technicians working
with hydrocarbon refrigerants follow proper safety precautions, such as
ensuring their workspace is well-ventilated and removing ignition
sources.
    Observance of OSHA requirements could further limit concentrations
and attendant flammability risks associated with those oils. For
example, OSHA has a PEL for one class of compressor oil, mineral oil
mist, of 5 mg/m\3\ of air, as well as rules for respiratory protection
and personal protective equipment that apply. EPA additionally notes
that the very small amount of dissolved compressor oil expected to be
used in the small hydrocarbon charge size required by the use
conditions will significantly mitigate the amount and the impact of any
release into the environment of lubricants dissolved in the hydrocarbon
refrigerant substitutes that may result from any venting, release or
disposal that may occur under this final action. EPA also notes that
many of the lubricants used with hydrocarbon refrigerants, such as
alkyl benzene and polyalkylene glycol, are considered environmentally
acceptable because they biodegrade easily, as noted in EPA's document
on environmentally acceptable lubricants, available in the docket.
    EPA received a similar comment on the rule exempting isobutane and
R-441A, as refrigerant substitutes in household refrigerators,
freezers, and combination refrigerators and freezers, and propane as a
refrigerant substitute in retail food refrigerators and freezers
(stand-alone units only) (see 79 FR

29682). EPA considered such studies and the influence of lubricant on
the LFLs of the hydrocarbon refrigerants in the specific end-uses in
that rule when finding them acceptable subject to use conditions under
the SNAP program (see December 20, 2011; 76 FR 78832, sections ``D.
Charge Size Limitation (Household Refrigeration)'' and ``E. Charge Size
Limitation (Retail Food Refrigeration)'' and discussions of Standards
UL 250 and UL 471 regarding lubricant oil). We believe that same
analysis and the same results are applicable here.
    Comment: A private citizen states that replacing old refrigerants
with new ones decreases the risk of toxicity yet increases a risk of
combustion. This commenter asked who would be responsible for fires due
to use and disposal of these refrigerants (e.g., junkyard owner,
appliance owner) and whether EPA and appliance manufacturers are
responsible for ensuring that the end user is aware of risks from the
usage and disposal of flammable refrigerants.
    Response: In this rule, EPA is exempting certain hydrocarbon
refrigerants in specific applications from the venting prohibition, not
making a determination of fault for individual incidents such as fires,
which global experience indicates can be prevented with appropriate
precautions. Thus, the commenter's point about who would be responsible
for fires is outside the scope of this rulemaking. With respect to the
commenter's concerns about the end-user's awareness, in the Agency's
risk screen, we have assessed a worst-case scenario for consumer
exposure (available in the docket for this rulemaking). Even in that
worst-case scenario, the charge size for these approved applications is
small enough that if the complete charge is lost within one minute in a
confined space, the amount released does not reach the LFL, and
therefore, a fire would not occur. Further, charges in the analyzed
scenarios do not exceed the relevant exposure limits, and therefore,
there should not be a significant toxicity risk. Since junkyards, scrap
yards, and other facilities disposing of or recycling small appliances
are already bound by the venting prohibition, they should already have
a system in place to determine whether an appliance contains an ODS or
substitute refrigerant. EPA believes that the required labeling of the
product and prominent red marking on the refrigeration circuit will
help these facilities to identify that the appliance contains a
flammable refrigerant. Thus, these facilities likely have procedures in
place to identify and appropriately handle flammable refrigerant
substitutes, whether or not they are subject to an exemption from the
venting prohibition. See also EPA's guidance in the further information
column in 40 CFR part 82, subpart G, Appendix R, concerning appropriate
personal protective equipment (PPE), type of fire extinguisher to use,
use of spark-proof tools, use of recovery equipment designed for
flammable refrigerants, and releasing refrigerant to well-ventilated
areas.
    Comment: Traulsen and NAFEM stated that EPA should reevaluate the
suggestion that venting should be conducted outside of a building
because of local codes, lease terms, or logistical concerns that may
make outdoor venting disruptive or even impossible. One of these
commenters, Traulsen, also is concerned that EPA has not yet outlined
what a network of properly trained service professionals to handle
venting practices safely would consist of, yet assumes that one will
exist.
    Response: EPA is not requiring that flammable refrigerant
substitutes from appliances be vented, nor that they be vented outside.
We recognize that outdoor venting may not always be feasible and that
such activity may be restricted by fire codes. Venting outdoors is
likely to allow sufficient ventilation to reduce concentrations and
mitigate flammability risks, but sufficient ventilation could also be
provided by engineered ventilation systems. Some manufacturers and end-
users may instead choose to recover flammable refrigerants rather than
venting. While the use conditions under SNAP finalized by this action,
in particular charge size, will minimize safety risk, other precautions
are recommended, like ensuring proper ventilation and avoiding ignition
sources during servicing. These would also be appropriate guidelines,
whether venting or recovering the refrigerant. AIRAH provides useful
guidance on safety precautions technicians can follow when servicing
equipment with flammable refrigerants. One of those practices is to
connect a hose to the appliance to allow for venting the refrigerant
outside. This document is included in the docket for this rule. We note
that at least two organizations, RSES and the ESCO Institute, already
offer training for handling of flammable refrigerants, which is the
first step to building a network of properly trained technicians.
Similarly, equipment manufacturers and end-users that have sent EPA
SNAP submissions for flammable refrigerants have indicated that there
is technician training for their own staff and for contractors
responsible for servicing appliances. Also, the Agency intends to
update the test bank for technician certification under Section 608 of
the CAA as we have done previously, and will consider including
additional questions on flammable refrigerants. By adding such
questions to the test bank, EPA would supplement but would not replace
technician training programs currently provided by non-government
entities. We will seek additional information and guidance on how best
to incorporate this content through a separate process outside of this
final rule.
    Comment: Traulsen has not found a solution regarding EPA's question
about an industry standard for hydrocarbon recovery units and their
availability in the U.S. market. No other commenters provided
information on such an industry standard.
    Response: EPA is not aware of an industry standard for hydrocarbon
recovery equipment, but encourages industry to develop one. However,
the agency is aware of the existence of some hydrocarbon recovery
devices. One of those recovery devices uses activated carbon to assist
in the safe removal of hydrocarbons from appliances. A canister
containing activated carbon is pulled to a 25 in.Hg vacuum. The
canister is then filled with nitrogen up to 10 psi and pulled to a
vacuum again to bring oxygen levels below 0.1% in the cylinder, thereby
preventing conditions that might allow ignition. The canister is then
attached to the appliance containing a hydrocarbon refrigerant. The
hydrocarbon refrigerant is pulled from the appliance into the canister
and the canister is then sealed off. This can be done with no pump or
other electrical equipment near the equipment containing the flammable
refrigerant. The carbon within the canister bonds with the hydrocarbon,
eliminating its ability to oxidize or burn. Once the process is
complete, the hydrocarbon can be recovered from the canister and
appropriately managed for reuse or disposal. Given the lack of
additional information on standards for recovery equipment for
hydrocarbon refrigerant substitutes, and our finding that release of
the specific refrigerants in the specific end-uses identified in this
rule do not pose a threat to the environment, we continue to believe
there is reason for allowing venting of the hydrocarbon refrigerant
substitutes in the specified end-uses as an alternative to recovery.
    Comment: ISRI seeks clarification on how 40 CFR 82.156(f) applies
to the recycling of appliances with exempt substitutes that may be
vented pursuant to 40 CFR 82.154(a)(1).

    Response: Under 40 CFR 82.156(f), the person who takes the final
step in the disposal process (including but not limited to scrap
recyclers and landfill operators) of a small appliance, room AC, MVACs,
or MVAC-like appliances must either recover any remaining refrigerant
in accordance with the regulations or verify that refrigerant has been
evacuated previously. Since the current definition of refrigerant
excludes non-ozone-depleting refrigerant substitutes, these
recordkeeping requirements do not presently apply to the hydrocarbon
refrigerant substitutes in the specified end-uses that are the subject
of this action. The only requirement under 40 CFR part 82 Subpart F
that would have applied is the venting prohibition. However, since EPA
is exempting those hydrocarbons for the specific uses from the venting
prohibition in this final rule, that prohibition would no longer apply.
Moreover, as this action does not change the applicability of other
environmental regulations, other applicable environmental regulations
would continue to apply (e.g., under RCRA).
    Comment: ISRI notes that in the last rule exempting isobutane and
R-441A as refrigerant substitutes in household refrigerators, freezers,
and combination refrigerators and freezers, and propane as a
refrigerant substitute in retail food refrigerators and freezers
(stand-alone units only) (see 79 FR 29682), EPA stated that certain
hydrocarbons could be characterized as hazardous waste due to their
flammability (as defined under the RCRA regulations; see 40 CFR
261.21). The commenter notes that the agency also stated that
incidental releases of these hydrocarbons ``would not be subject to
RCRA requirements for the disposal of hazardous waste as the release
would occur incidentally during the maintenance, service and repair of
the equipment, and would not constitute disposal of the refrigerant
charge as solid waste, per se,'' (79 FR 29687). ISRI seeks clarity on
whether full venting is allowed if flammable refrigerants have been
exempted from the venting prohibition at 40 CFR 82.154(a). The
commenter also seeks clarity on whether hydrocarbons would be
considered hazardous waste under RCRA. The commenter suggests that EPA
could create a new exclusion from hazardous waste at 40 CFR 261.4(b)
for an acceptable ignitable refrigerant substitute, or determine that
an acceptable ignitable refrigerant is equivalent to household waste
under 40 CFR 261.4(b)(1).
    Response: In this rule, EPA is exempting from the venting
prohibition under CAA Section 608(c) certain hydrocarbons in certain
end-uses listed as acceptable subject to use conditions under SNAP.
Specifically, EPA is exempting from the venting prohibition the
following refrigerant substitutes in the following uses: (1) Isobutane
and R-441A in retail food refrigerators and freezers (stand-alone units
only); (2) propane in household refrigerators, freezers, and
combination refrigerators and freezers; (3) ethane in very low
temperature refrigeration equipment and equipment for non-mechanical
heat transfer; (4) R-441A, propane, and isobutane in vending machines;
and (5) propane and R-441A in self-contained room air conditioners for
residential and light commercial air conditioning and heat pumps.
    The commenter's request to modify the hazardous waste regulations
is beyond the scope of this rulemaking, since it focuses on Sections
608 and 612 of the CAA. However, as discussed in the final rule
exempting from the venting prohibition isobutane and R-441A, as
refrigerant substitutes in household refrigerators, freezers, and
combination refrigerators and freezers; and propane, as a refrigerant
substitute in retail food refrigerators and freezers (stand-alone units
only); incidental releases that occur during the maintenance, service,
and repair of appliances would not be subject to RCRA requirements for
the disposal of hazardous waste because this would not constitute
disposal of the refrigerant charge as a solid waste, per se (see 79 FR
29687).
    The commenter raises questions about how the hazardous waste
requirements under RCRA apply at disposal (or in the case of scrap
metal recycling, disassembly) of an appliance. Under the RCRA
requirements at 40 CFR part 261, it does appear that certain
refrigerants, like hydrocarbons, could potentially be subject to
regulation as hazardous wastes if they exhibit the ignitability
characteristic.
    In the case of household appliances, repair and disposal of
hydrocarbons would not be considered hazardous waste management because
the appliance is exempt from the hazardous waste regulations under the
household hazardous waste exemption at 40 CFR 261.4(b)(1) (although
States may have more stringent regulations). The refrigerant could
therefore generally be vented without triggering RCRA hazardous waste
requirements.
    On the other hand, for commercial and industrial appliances that
are not generated by households as defined in 40 CFR 261.4(b)(1),
ignitable refrigerants would be subject to regulation as hazardous
waste (see 40 CFR 261.21) subject to a limited exception if the
ignitable refrigerant is to be recycled. Ignitable refrigerant that has
been used and has become contaminated through use would fit the
definition of a spent material under RCRA (40 CFR 261.1(c)(1)) if it
must be reclaimed prior to its reuse. Spent materials that are
reclaimed are solid wastes per Section 261.2(c). However, if the
hydrocarbon refrigerant is recovered for direct reuse (i.e., no
reclamation), it would not be classified as a solid or a hazardous
waste (40 CFR 261.2(e)). EPA believes that recycling of these materials
would require cleaning before they are reused.

H. Cost and Economic Impacts

1. Equipment Redesign
    Comment: NAFEM and Hoshizaki America stated that refrigeration
equipment manufacturers would incur capital costs in switching to
flammable refrigerants because they would need to redesign equipment
and facilities to eliminate ignition sources to reduce the risk of
fire. Hoshizaki America stated that manufacturers would have to go
through considerable and costly staff training to understand the risks
of explosion for the proposed list of substitutes. Master-Bilt Products
stated that the large expenses for upgrading factories and additional
testing to meet different standards will slow innovation for their
business as well as other small businesses.
    Response: EPA agrees that manufacturers choosing to use one of the
refrigerants listed in this rule may need to make capital investments
in their facilities, including the redesign of equipment to handle
flammable refrigerants, and may need to invest in training their staff
to handle flammable refrigerants safely. These investments would be
needed for safe use of these refrigerants and would be needed
irrespective of use conditions established by EPA in listing these
refrigerants as acceptable subject to use conditions. Therefore
manufacturers may decide, based on their own business considerations,
whether to pursue hydrocarbon refrigerants. This rule does not restrict
nonflammable substitutes currently in use nor does it require
manufacturers to use any of the flammable substitute refrigerants
listed through this action.
    Comment: Master-Bilt commented that if multiple systems using the
150 g charge can be used in larger models, propane could potentially be
used in some larger equipment, but the cost would go up approximately
25-50% and the systems would be more complex.

    Response: The 150 g limit applies to each refrigerant circuit and
multiple circuits could be used in the same piece of equipment, as
discussed above under section VI.E.3. We agree with the commenter that
the cost for models that have multiple circuits could be higher and
that the systems would be more complex. We are not requiring
manufacturers to use propane or any of the substitute refrigerants
listed in this action.
2. Market Options
    Comment: Traulsen believes this rule will give the industry more
flexibility to explore market options. EIA believes the rule will allow
U.S. businesses to sell international products domestically and
encourage foreign businesses to expand their manufacturing operations
and distribution in the United States.
    Response: EPA agrees with the commenters. Whenever the Agency
expands the list of acceptable substitutes it provides industry,
including manufacturers, with more flexibility and options.
3. Recycling
    Comment: ISRI is concerned that EPA may not have adequately
considered the impacts of the proposed rule on the recycling industry.
The commenter stated that, for example, the recycling industry (NAICS
423930) was not even identified as potentially affected in Table 1 of
the proposed rule.
    Response: EPA has added the recycling industry in Table 1 in this
final rule. Further, EPA has performed research to consider impacts of
the rule on the recycling industry more fully (ICF, 2015b). We
investigated the impacts of use of flammable refrigerants in waste
streams of other countries using these refrigerants. This analysis
found that it is not anticipated that the recycling industry will
experience additional risk if appliances containing hydrocarbon
refrigerants are sent to recycling facilities prior to the refrigerant
being properly vented or evacuated. This analysis suggested that
recycling facilities should vent or otherwise remove the refrigerant
(consistent with other requirements like RCRA) before any mechanical
processing of the appliance (e.g., shredders, choppers, magnets), due
to the potential presence of ignition sources. Further, based upon
experience with flammable refrigerants in Europe, Australia, and Japan,
there are best practices for handling flammable refrigerants at
disposal, such as those provided by AIRAH (2013).

I. Statutory and Executive Order Reviews

    Comment: Traulsen stated that EPA's rule adding to the list of
acceptable SNAP substitutes may not be affected by the Regulatory
Flexibility Act (RFA), but any requirement related to the removal of a
previously approved substance would violate the RFA. Traulsen expressed
concern about the potential future impacts on small businesses if
flammable refrigerants, including the proposed refrigerants, become the
only refrigerant options available, combined with uncertainties such as