[Federal Register Volume 87, Number 13 (Thursday, January 20, 2022)]
[Rules and Regulations]
[Pages 3037-3045]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-00998]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 82

[EPA-HQ-OAR-2003-0118; FRL-9445-01-OAR]
RIN 2060-AG12


Protection of Stratospheric Ozone: Determination 37 for 
Significant New Alternatives Policy Program

AGENCY: Environmental Protection Agency (EPA).

ACTION: Determination of acceptability.

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SUMMARY: This determination of acceptability expands the list of 
acceptable substitutes pursuant to the U.S. Environmental Protection 
Agency's Significant New Alternatives Policy program. This action lists 
as acceptable additional substitutes for use in the refrigeration and 
air conditioning; foam blowing; aerosols; cleaning solvents; and 
adhesives, coatings, and inks sectors.

DATES: This determination is applicable on January 20, 2022.

ADDRESSES: EPA established a docket for this action under Docket ID No. 
EPA-HQ-OAR-2003-0118 (continuation of Air Docket A-91-42). All 
electronic documents in the docket are listed in the index at 
www.regulations.gov. Although listed in the index, some information is 
not publicly available, i.e., Confidential Business Information (CBI) 
or other information whose disclosure is restricted by statute. 
Publicly available docket materials are available either electronically 
at www.regulations.gov or in hard copy at the EPA Air Docket (Nos. A-
91-42 and EPA-HQ-OAR-2003-0118), EPA Docket Center (EPA/DC), William J. 
Clinton West, Room 3334, 1301 Constitution Avenue NW, Washington, DC 
20460. The telephone number for the Public Reading Room is (202) 566-
1744, and the telephone number for the Air Docket is (202) 566-1742. 
Out of an abundance of caution for members of the public and our staff, 
the EPA Docket Center and Reading Room are closed to public visitors, 
with limited exceptions, to reduce the risk of transmitting COVID-19. 
Our Docket Center staff will continue to provide remote customer 
service via email, phone, and webform. For further information on EPA 
Docket Center services and the current status, please visit us online 
at https://www.epa.gov/dockets.

FOR FURTHER INFORMATION CONTACT: Gerald Wozniak by telephone at (202) 
343-9624, by email at [email protected], or by mail at U.S. 
Environmental Protection Agency, Mail Code 6205T, 1200 Pennsylvania 
Avenue NW, Washington, DC 20460. Overnight or courier deliveries should 
be sent to the office location at 1201 Constitution Avenue NW, 
Washington, DC 20004.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Listing of New Acceptable Substitutes
    A. Refrigeration and Air Conditioning
    B. Foam Blowing
    C. Aerosols
    D. Cleaning Solvents
    E. Adhesives, Coatings, and Inks
Appendix A: Summary of Decisions for New Acceptable Substitutes

I. Listing of New Acceptable Substitutes

    This action is listing as acceptable additional substitutes for use 
in the refrigeration and air conditioning; foam blowing; aerosols; 
cleaning solvents; and adhesives, coatings and inks sectors. This 
action presents EPA's most recent decision under the Significant New 
Alternatives Policy (SNAP) program to list as acceptable several 
substitutes in different end-uses. New substitutes are:
     Hydrochlorofluoroolefin (HCFO)-1233zd(E) in cold storage 
warehouses,

[[Page 3038]]

ice skating rinks and industrial process air conditioning (new 
equipment only);
     Blends of 10 to 90 percent hydrofluoroolefin (HFO)-
1234ze(E) by weight and the remainder HCFO-1233zd(E) in polystyrene: 
Extruded boardstock and billet (XPS);
     Blends of 10 to 90 percent HFO-1234ze(E) by weight and the 
remainder hydrofluorocarbon (HFC)-152a in XPS;
     Blends of zero to 100 percent HFO-1234ze(E), zero to 70 
percent methyl formate, zero to 60 percent HFC-152a, zero to 60 percent 
carbon dioxide (CO2), and zero to 60 percent water in XPS; 
and
     HCFO-1233yd(Z) in electronics cleaning, metals cleaning, 
precision cleaning, aerosol solvents, and coatings.
    EPA's review of certain substitutes listed in this document is 
pending for other end-uses. Listing decisions in the end-uses in this 
document do not prejudge EPA's listings of these substitutes for other 
end-uses. While certain substitutes being added through this action to 
the acceptable lists for specific end-uses may have a higher risk in 
one or more SNAP criteria than certain other substitutes already listed 
as acceptable or acceptable subject to restrictions, they have a 
similar or lower overall risk than other acceptable substitutes in 
those end-uses.
    For additional information on SNAP, visit the SNAP portion of EPA's 
Ozone Layer Protection website at: www.epa.gov/snap. Copies of the full 
lists of acceptable substitutes for ozone-depleting substances (ODS) in 
the industrial sectors covered by the SNAP program are available at 
www.epa.gov/snap/substitutes-sector. For more information on the 
Agency's process for administering the SNAP program or criteria for 
evaluation of substitutes, refer to the initial SNAP rulemaking 
published March 18, 1994 (59 FR 13044), and the regulations codified at 
40 CFR part 82, subpart G. SNAP decisions and the appropriate Federal 
Register citations are found at: www.epa.gov/snap/snap-regulations. 
Substitutes listed as unacceptable; acceptable, subject to narrowed use 
limits; or acceptable, subject to use conditions are also listed in the 
appendices to 40 CFR part 82, subpart G.
    The sections below discuss each substitute listing in detail. 
Appendix A contains tables summarizing each listing decision in this 
action. The statements in the ``Further Information'' column in the 
tables provide additional information but these are not legally binding 
under section 612 of the Clean Air Act (CAA). Although you are not 
required to follow recommendations in the ``Further Information'' 
column of the table under section 612 of the CAA, some of these 
statements may refer to obligations that are enforceable or binding 
under federal or state programs other than the SNAP program. The 
identification of other enforceable or binding requirements should not 
be construed as a comprehensive list of such obligations. In many 
instances, the information simply refers to standard operating 
practices in existing industry standards and/or building codes. When 
using these substitutes in the identified end-use, EPA strongly 
encourages you to apply the information in the ``Further Information'' 
column. Many of these recommendations, if adopted, would not require 
significant changes to existing operating practices.
    You can find submissions to EPA for the substitutes listed in this 
document, as well as other materials supporting the decisions in this 
action, in Docket EPA-HQ-OAR-2003-0118 at www.regulations.gov.

A. Refrigeration and Air Conditioning

1. HCFO-1233zd(E)
    EPA's decision: EPA finds HCFO-1233zd(E) acceptable as a substitute 
for use in:

 Cold storage warehouses (new equipment only)
 Ice skating rinks (new equipment only)
 Industrial process air conditioning (new equipment only)

    HCFO-1233zd(E), marketed under the trade name Solstice[supreg]zd, 
is also known as trans-1-chloro-3,3,3-trifluoroprop-1-ene (Chemical 
Abstracts Service Registry Number [CAS Reg. No.] 102687-65-0).
    You may find a copy of the applicant's submission, with CBI 
redacted, providing the required health and environmental information 
for this substitute in this end-use in Docket EPA-HQ-OAR-2003-0118 at 
www.regulations.gov under the name, ``Supporting Materials for Notice 
37 Listing of HCFO-1233zd(E) in Refrigeration and Air Conditioning. 
SNAP Submission Received October 7, 2019.'' EPA performed an assessment 
to examine the health and environmental risks of this substitute. These 
assessments are available in Docket EPA-HQ-OAR-2003-0118:
     ``Risk Screen on Substitutes in Cold Storage Warehouses 
and Industrial Process Air Conditioning. Substitute: HCFO-1233zd(E).''
     ``Risk Screen on Substitutes in Ice Skating Rinks. 
Substitute: HCFO-1233zd(E).''
    EPA previously listed HCFO-1233zd(E) as acceptable for use in 
several refrigeration and air conditioning and foam blowing end-uses 
(December 11, 2020, 85 FR 79863; August 10, 2012, 77 FR 47768; October 
21, 2014, 79 FR 62863).
    Environmental information: HCFO-1233zd(E) has an ozone depletion 
potential (ODP) of less than 0.0004 and a global warming potential 
(GWP) of 3.7.\1\ HCFO-1233zd(E) is excluded from the definition of 
volatile organic compounds (VOC) under CAA regulations (see 40 CFR 
51.100(s)) addressing the development of state implementation plans 
(SIPs) to attain and maintain the National Ambient Air Quality 
Standards (NAAQS). Knowingly venting or releasing this refrigerant 
blend is limited by the venting prohibition under section 608(c)(2) of 
the CAA, codified in EPA's regulations at 40 CFR 82.154(a).
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    \1\ WMO (World Meteorological Organization), Scientific 
Assessment of Ozone Depletion: 2018, Global Ozone Research and 
Monitoring Project--Report No. 58, 588 pp., Geneva, Switzerland, 
2018. Available at: https://ozone.unep.org/sites/default/files/2019-05/SAP-2018-Assessment-report.pdf. In this action, the 100-year GWP 
values are used.
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    Flammability information: HCFO-1233zd(E) is not flammable.
    Toxicity and exposure data: Potential health effects of exposure to 
this substitute include drowsiness or dizziness. The substitute may 
also irritate the skin or eyes or cause frostbite. The substitute could 
cause asphyxiation if air is displaced by vapors in a confined space. 
These potential health effects are common to many refrigerants.
    The Workplace Environmental Exposure Limit (WEEL) Committee of the 
Occupational Alliance for Risk Science (OARS) has established a WEEL of 
800 ppm on an eight-hour time-weighted average (8-hr TWA) for HCFO-
1233zd(E). EPA anticipates that users will be able to meet the WEEL and 
address potential health risks by following requirements and 
recommendations in the manufacturer's safety data sheet (SDS), American 
Society of Heating, Refrigerating, and Air-Conditioning Engineers 
(ASHRAE) Standard 15, and other safety precautions common to the 
refrigeration and air conditioning industry.
    Comparison to other substitutes in these end-uses: HCFO-1233zd(E) 
has an ODP of less than 0.0004, comparable to or less than other listed 
substitutes in these end-uses with ODPs ranging from zero to 0.098.
    For cold storage warehouses, HCFO-1233zd(E)'s GWP of about 3.7 is 
comparable to or lower than that of

[[Page 3039]]

other acceptable substitutes for new equipment such as ammonia 
absorption, CO2, R-450A, R-513A, and R-407C, with GWPs \2\ 
ranging from zero to 1,770.
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    \2\ Unless otherwise stated, all GWPs in this document for 
individual chemicals are 100-year values from: IPCC, 2007: Climate 
Change 2007: The Physical Science Basis. Contribution of Working 
Group I to the Fourth Assessment Report of the Intergovernmental 
Panel on Climate Change [Solomon, S., Qin, D., Manning, M., Chen, 
Z., Marquis, M., Averyt, K.B., Tignor M., and Miller, H.L. (eds.)]. 
Cambridge University Press, Cambridge, United Kingdom and New York, 
NY, USA. This document is accessible at www.ipcc.ch/
publications_and_data/ar4/wg1/en/contents.html. For blends of 
chemicals, such as R-507A, this document weights the GWPs of each 
component of the blend by their mass percentage in the blend, based 
upon the 100-year GWPs in IPCC, 2007, if available in that document.
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    For ice skating rinks and industrial process air conditioning, 
HCFO-1233zd(E)'s GWP of about 3.7 is comparable to or lower than that 
of other acceptable substitutes for new equipment such as ammonia 
absorption, CO2, R-450A, R-513A, and R-507A, with GWPs 
ranging from zero to 3,990.
    Flammability and toxicity risks are comparable to or lower than 
flammability and toxicity risks of other available substitutes in the 
same end-uses. Toxicity risks can be minimized by use consistent with 
the OARS WEEL, ASHRAE 15, and other industry standards, recommendations 
in the manufacturer's SDS, and other safety precautions common in the 
refrigeration and air conditioning industry.
    EPA finds HCFO-1233zd(E) acceptable in the cold storage warehouses 
(new equipment only), ice skating rinks (new equipment only) and 
industrial process air conditioning (new equipment only) end-uses 
because it does not pose greater overall environmental and human health 
risk than other available substitutes in the same end-uses.

B. Foam Blowing

1. Blends of 10 to 90 Percent HFO-1234ze(E) by Weight and the Remainder 
HCFO-1233zd(E)
    EPA's decision: EPA finds blends of 10 to 90 percent HFO-1234ze(E) 
by weight and the remainder HCFO-1233zd(E) acceptable as a substitute 
for use as a blowing agent in:

 Polystyrene: Extruded boardstock and billet

    These blends range in composition from 10 percent HFO-1234ze(E) and 
90 percent HCFO-1233zd(E) to 90 percent HFO-1234ze(E) and 10 percent 
HCFO-1233zd(E). Accordingly, these blends are referred to as blends of 
10 to 90 percent by weight HFO-1234ze(E) and the remainder HCFO-
1233zd(E), or hereafter in this action as ``HFO-1234ze(E)/HCFO-
1233zd(E) co-blowing blends''; they also go by the trade name of 
Solstice[supreg] XBA-1. HFO-1234ze(E) is also called 1,3,3,3-
tetrafluoropropene (E), or trans-1,3,3,3-tetrafluoropropene (CAS Reg. 
No. 29118-24-9). HCFO-1233zd(E) is also called trans-1-chloro-3,3,3-
trifluoro-prop-1-ene (CAS Reg. No. 102687-65-0).
    You may find a copy of the applicant's submission, with CBI 
redacted, providing the required health and environmental information 
for this substitute in this end-use in Docket EPA-HQ-OAR-2003-0118 at 
www.regulations.gov under the name, ``Supporting Materials for Notice 
37 Listing Blends of 10 to 90 Percent HFO-1234ze(E) by Weight and the 
Remainder HCFO-1233zd(E) as a Foam Blowing Agent. SNAP Submission 
Received November 4, 2019.'' EPA has performed an assessment to examine 
the health and environmental risks of this substitute. This assessment 
is available in docket EPA-HQ-OAR-2003-0118 under the name ``Risk 
Screen on Substitutes in Extruded Polystyrene Boardstock and Billet 
Foam Substitute: Blends of 10 to 90 Percent HFO-1234ze(E) by Weight and 
the Remainder HCFO-1233zd(E) (Solstice[supreg] XBA-1).''
    Environmental information: HFO-1234ze(E) has an ODP of zero and 
HCFO-1233zd(E) has an ODP of less than 0.0004.\3\ If these values are 
weighted by mass percentage, then these HFO-1234ze(E)/HCFO-1233zd(E) 
co-blowing blends have an ODP ranging from less than 0.0004 to less 
than 0.00004. Their components, HFO-1234ze(E) and HCFO-1233zd(E), have 
GWPs of less than one \4\ and 3.7, respectively. If these values are 
weighted by mass percentage, then the blends range in GWP from about 
1.3 to about 3.4. Both components of the blends are excluded from the 
definition of VOC under CAA regulations (see 40 CFR 51.100(s)) 
addressing the development of SIPs to attain and maintain the NAAQS.
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    \3\ WMO (World Meteorological Organization), Scientific 
Assessment of Ozone Depletion: 2018, Global Ozone Research and 
Monitoring Project--Report No. 58, 588 pp., Geneva, Switzerland, 
2018. Available at: https://ozone.unep.org/sites/default/files/2019-05/SAP-2018-Assessment-report.pdf. (WMO, 2018)
    \4\ WMO, 2018.
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    Flammability information: The component HCFO-1233zd(E) is non-
flammable. HFO-1234ze(E) is not flammable at standard temperature and 
pressure using the standard test method American Society for Testing 
and Materials (ASTM) E681. However, at higher temperatures, such as the 
temperatures typical for extruding XPS, HFO-1234ze(E) may also be 
flammable, particularly at higher humidity levels.\5\
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    \5\ Bellair and Hood, 2019. Comprehensive evaluation of the 
flammability and ignitability of HFO-1234ze, R.J. Bellair and L. 
Hood, Process Safety and Environmental Protection 132 (2019) 273-
284. Available online at doi.org/10.1016/j.psep.2019.09.033.
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    Toxicity and exposure data: Potential health effects of these 
substitutes at lower concentrations include drowsiness and dizziness. 
Potential health effects also include skin or eye irritation or 
frostbite. The components of HFO-1234ze(E)/HCFO-1233zd(E) co-blowing 
blends can cause symptoms of asphyxiation when present at sufficiently 
high concentrations. Excessive inhalation of the substitute may also 
result in an irregular heartbeat, due to cardiac effects. These 
potential health effects are common to many foam blowing agents.
    The American Industrial Hygiene Association (AIHA) has established 
a WEEL of 800 ppm as an 8-hr TWA for HFO-1234ze(E), and OARS's WEEL 
committee has established a WEEL of 800 ppm for HCFO-1233zd(E). EPA 
anticipates that users will be able to meet the AIHA and OARS WEELs and 
address potential health risks by following requirements and 
recommendations in the manufacturer's SDSs and other safety precautions 
common to the foam blowing industry.
    Comparison to other substitutes in this end-use: These HFO-
1234ze(E)/HCFO-1233zd(E) co-blowing blends have an ODP ranging from 
less than 0.0004 to less than 0.00004, comparable to all other 
acceptable substitutes in this end-use, such as blends of 10 to 99 
percent by weight HFO-1336mzz(Z) and the remainder HFC-152a (hereafter 
in this action ``HFO-1336mzz(Z)/HFC-152a blends''), HFO-1234ze(E), 
methyl formate, and CO2. These HFO-1234ze(E)/HCFO-1233zd(E) 
blends' GWPs from about 1.3 to 3.4 are lower than or comparable to 
those of other acceptable substitutes in the same end-use for which we 
are finding it acceptable, such as HFO-1336mzz(Z)/HFC-152a blends, HFO-
1234ze(E), light saturated hydrocarbons C3-C6 \6\ and methyl formate, 
with respective GWPs

[[Page 3040]]

of approximately three to 110,\7\ 124, one,\8\ less than one,\9\ and 
11.\10\
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    \6\ That is, alkanes with three to six carbons such as butane, 
n-pentane, isopentane, and cyclopentane.
    \7\ HFO-1336mzz(Z) and HFC-152a have GWPs of about two (WMO, 
2018) and 124 (IPCC, 2007), respectively. If these values are 
weighted by mass percentage, then the blends range in GWP from about 
three to about 110.
    \8\ WMO (World Meteorological Organization), Scientific 
Assessment of Ozone Depletion: 2018, Global Ozone Research and 
Monitoring Project--Report No. 58, 588 pp., Geneva, Switzerland, 
2018. Available at: https://ozone.unep.org/sites/default/files/2019-05/SAP-2018-Assessment-report.pdf.
    \9\ Ibid.
    \10\ Ibid.
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    Flammability and toxicity risks are comparable to or lower than 
flammability and toxicity risks of other available substitutes in the 
same end-use. Some acceptable substitutes in this end-use are 
flammable, like HFC-152a, light saturated hydrocarbons C3-C6, and 
methyl formate, while others are non-flammable. Toxicity risks can be 
minimized by use consistent with the AIHA's and OARS's WEELs, 
recommendations in the SDS, and other safety precautions common in the 
foam blowing industry.
    EPA finds blends of 10 to 90 percent by weight HFO-1234ze(E) and 
the remainder HCFO-1233zd(E) acceptable in the XPS end-use because they 
do not pose greater overall environmental and human health risk than 
other available substitutes in the same end-use.
2. Blends of 10 to 90 Percent HFO-1234ze(E) by Weight and the Remainder 
HFC-152a
    EPA's decision: EPA finds blends of 10 to 90 percent HFO-1234ze(E) 
by weight and the remainder HFC-152a acceptable as a substitute for use 
as a blowing agent in:

 Polystyrene: Extruded boardstock and billet

    These blends range in composition from 10 percent HFO-1234ze(E) and 
90 percent HFC-152a to 90 percent HFO-1234ze(E) and 10 percent HFC-
152a. Accordingly, these blends are also referred to as blends of 10 to 
90 percent by weight HFO-1234ze(E) and the remainder HFC-152a, or 
hereafter in this action as ``HFO-1234ze(E)/HFC-152a co-blowing 
blends''; they also go by the trade name of Solstice[supreg] XBA-2. 
HFO-1234ze(E) is also called 1,3,3,3-tetrafluoropropene (E), or trans-
1,3,3,3-tetrafluoropropene (CAS Reg. No. 29118-24-9). HFC-152a is also 
called 1,1-difluoroethane (CAS Reg. No. 75-37-6).
    You may find a copy of the applicant's submission, with CBI 
redacted, providing the required health and environmental information 
for this substitute in this end-use in Docket EPA-HQ-OAR-2003-0118 at 
www.regulations.gov under the name, ``Supporting Materials for Notice 
37 Listing Blends of 10 to 90 Percent HFO-1234ze(E) by Weight and the 
Remainder HFC-152a as a Foam Blowing Agent. SNAP Submission Received 
November 4, 2019.'' EPA has performed an assessment to examine the 
health and environmental risks of this substitute. This assessment is 
available in docket EPA-HQ-OAR-2003-0118 under the name ``Risk Screen 
on Substitutes in Extruded Polystyrene Boardstock and Billet Foam 
Substitute: Blends of 10 to 90 Percent HFO-1234ze(E) by Weight and the 
Remainder HFC-152a (Solstice[supreg] XBA-2).''
    Environmental information: These HFO-1234ze(E)/HFC-152a co-blowing 
blends and their components have an ODP of zero. Their components, HFO-
1234ze(E) and HFC-152a, have GWPs of less than one \11\ and 124, 
respectively. If these values are weighted by mass percentage, then the 
blends range in GWP from about 13 to about 112. Both components of the 
blends are excluded from the definition of VOC under CAA regulations 
(see 40 CFR 51.100(s)) addressing the development of SIPs to attain and 
maintain the NAAQS.
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    \11\ WMO (World Meteorological Organization), Scientific 
Assessment of Ozone Depletion: 2018, Global Ozone Research and 
Monitoring Project--Report No. 58, 588 pp., Geneva, Switzerland, 
2018. Available at: https://ozone.unep.org/sites/default/files/2019-05/SAP-2018-Assessment-report.pdf.
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    Flammability information: The component HFC-152a is flammable while 
the component HFO-1234ze(E) is not flammable at standard temperature 
and pressure using the standard test method ASTM E681. However, at 
higher temperatures, such as the temperatures typical for extruding 
XPS, HFO-1234ze(E) may also be flammable, particularly at higher 
humidity levels.\12\
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    \12\ Bellair and Hood, 2019. Comprehensive evaluation of the 
flammability and ignitability of HFO-1234ze, R.J. Bellair and L. 
Hood, Process Safety and Environmental Protection 132 (2019) 273-
284. Available online at doi.org/10.1016/j.psep.2019.09.033.
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    Toxicity and exposure data: Potential health effects of these 
substitutes at lower concentrations include drowsiness and dizziness. 
Potential health effects also include skin or eye irritation or 
frostbite. The components of HFO-1234ze(E)/HFC-152a blends can cause 
symptoms of asphyxiation when present at sufficiently high 
concentrations. Excessive inhalation of the substitute may also result 
in an irregular heartbeat, due to cardiac effects. These potential 
health effects are common to many foam blowing agents.
    The AIHA has established WEELs of 1,000 ppm for HFC-152a, and of 
800 ppm for HFO-1234ze(E), both as an 8-hr TWA. EPA anticipates that 
users will be able to meet the AIHA WEELs and address potential health 
risks by following requirements and recommendations in the 
manufacturer's SDSs and other safety precautions common to the foam 
blowing industry.
    Comparison to other substitutes in this end-use: These HFO-
1234ze(E)/HFC-152a co-blowing blends have an ODP of zero, comparable to 
all other acceptable substitutes in this end-use, such as HFO-
1336mzz(Z)/HFC-152a blends, HFC-152a, HFO-1234ze(E), methyl formate, 
and CO2. These HFO-1234ze(E)/HFC-152a co-blowing blends' 
GWPs from about 13 to 112 are lower than or comparable to those of 
other acceptable substitutes in the same end-use for which we are 
finding them acceptable, such as HFO-1336mzz(Z)/HFC-152a blends and 
HFC-152a with respective GWPs of approximately three to 110 \13\ and 
124. The GWPs of the HFO-1234ze(E)/HFC-152a co-blowing blends of about 
13 to 112 are higher than those for acceptable alternatives such as 
HFO-1234ze(E), light saturated hydrocarbons C3-C6 and methyl formate, 
with respective GWPs of one,\14\ less than one,\15\ and 11.\16\ Based 
on current information, EPA anticipates that HFO-1234ze(E), light 
saturated hydrocarbons C3-C6 and methyl formate are not currently being 
used as the sole blowing agent by any U.S. manufacturers in this end-
use because the individual chemicals have drawbacks such as 
insufficient vapor pressure, insufficient solubility in the polystyrene 
matrix, or high permeability resulting in low thermal resistance (``R-
value''); blends such as these HFO-1234ze(E)/HFC-152a co-blowing blends 
are expected to result in a feasible balance of blowing agent 
properties for adequate or better performance.
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    \13\ HFO-1336mzz(Z) and HFC-152a have GWPs of about two (WMO, 
2018) and 124 (IPCC, 2007), respectively. If these values are 
weighted by mass percentage, then the blends range in GWP from about 
three to about 110.
    \14\ WMO (World Meteorological Organization), Scientific 
Assessment of Ozone Depletion: 2018, Global Ozone Research and 
Monitoring Project--Report No. 58, 588 pp., Geneva, Switzerland, 
2018. Available at: https://ozone.unep.org/sites/default/files/2019-05/SAP-2018-Assessment-report.pdf.
    \15\ Ibid.
    \16\ Ibid.
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    Flammability and toxicity risks are comparable to or lower than 
flammability and toxicity risks of other available substitutes in the 
same end-use. Some acceptable substitutes in this end-use are 
flammable, like HFC-152a, light saturated hydrocarbons C3-C6, and 
methyl formate, while others are non-flammable. Toxicity risks can be 
minimized by use consistent with the

[[Page 3041]]

AIHA's WEELs, recommendations in the SDS, and other safety precautions 
common in the foam blowing industry.
    EPA finds blends of 10 to 90 percent by weight HFO-1234ze(E) and 
the remainder HFC-152a acceptable in the XPS end-use because they do 
not pose greater overall environmental and human health risk than other 
available substitutes in the same end-use.
3. Blends of Zero to 100 Percent HFO-1234ze(E), Zero to 70 Percent 
Methyl Formate, Zero to 60 Percent HFC-152a, Zero to 60 Percent 
CO2 and Zero to 60 Percent Water
    EPA's decision: EPA finds blends of zero to 100 percent HFO-
1234ze(E), zero to 70 percent methyl formate, zero to 60 percent HFC-
152a, zero to 60 percent CO2 and zero to 60 percent water acceptable as 
a substitute for use as a blowing agent in:

 Polystyrene: Extruded boardstock and billet

    These blends are hereafter referred to as ``HFO-1234ze(E)/methyl 
formate/HFC-152a/CO2/water co-blowing blends.'' The 
components of the blends are co-blown and component percentages are by 
weight.
    HFO-1234ze(E) is also known as HFC-1234ze, HFO-1234ze or trans-
1,3,3,3-tetrafluoroprop-1-ene (CAS Reg. No. 29118-24-9). Methyl formate 
is also known as methyl methanoate or formic acid, methyl ester (CAS 
Reg. No. 107-31-3). HFC-152a, also known as 1,1-difluoroethane, has CAS 
Reg. No. 75-37-6. CO2 has CAS Reg. No. 124-38-9, and water 
has CAS Reg. No. 7732-18-5.
    You may find a copy of the applicant's submission, with CBI 
redacted, providing the required health and environmental information 
for this substitute in this end-use in Docket EPA-HQ-OAR-2003-0118 at 
www.regulations.gov under the name, ``Supporting Materials for Notice 
37 Listing Blends of 0-100% HFO-1234ze(E), 0-70% Methyl Formate, 0-60% 
HFC-152a, 0-60% CO2 and 0-60% Water as a Foam Blowing Agent. 
SNAP Submission Received January 26, 2021.'' EPA has performed an 
assessment to examine the health and environmental risks of this 
substitute. This assessment is available in docket EPA-HQ-OAR-2003-0118 
under the name ``Risk Screen on Substitutes in Extruded Polystyrene 
Boardstock and Billet Foam Substitute: HFO-1234ze(E)/Methyl Formate/
HFC-152a/CO2/Water Co-blowing Blends for Extruded 
Polystyrene Foam Insulation (HFO-1234ze(E)/Methyl Formate/HFC-152a/
CO2/Water Co-blowing Blends).''
    Environmental information: The blends have an ODP of zero. Their 
components, HFO-1234ze(E), methyl formate, HFC-152a, CO2, 
and water have GWPs of one,\17\ 11,\18\ 124,\19\ one,\20\ and less than 
one,\21\ respectively. If these values are weighted by mass percentage, 
then the blends could have a GWP ranging from one to 80. HFO-1234ze(E), 
methyl formate, HFC-152a, CO2, and water--components of the 
blends--are excluded from EPA's regulatory definition of VOC under CAA 
regulations that address the development of SIPs to attain and maintain 
the NAAQS. See 40 CFR 51.100(s).
---------------------------------------------------------------------------

    \17\ WMO (World Meteorological Organization), Scientific 
Assessment of Ozone Depletion: 2018, Global Ozone Research and 
Monitoring Project--Report No. 58, 588 pp., Geneva, Switzerland, 
2018. Available at: https://ozone.unep.org/sites/default/files/2019-05/SAP-2018-Assessment-report.pdf. In this action, the 100-year GWP 
values are used.
    \18\ WMO, 2018.
    \19\ IPCC, 2007.
    \20\ IPCC, 2007.
    \21\ Sherwood et al. 2018. This paper estimated that water vapor 
emitted near Earth's surface due to anthropogenic sources (e.g., 
irrigation) would have a GWP of -10-\3\ to 5 x 10-\4\. 
``The global warming potential of near-surface emitted water 
vapour,'' Steven C. Sherwood, Vishal Dixit and Chrys[eacute]is 
Salomez. Environ. Res. Lett. 13 (2018) 104006.
---------------------------------------------------------------------------

    Flammability information: The components HFC-152a and methyl 
formate are flammable while the other components of the blends are non-
flammable at standard temperature and pressure using the standard test 
method ASTM E681. However, at higher temperatures, such as the 
temperatures typical for extruding XPS, HFO-1234ze(E) may also be 
flammable, particularly at higher humidity levels.\22\
---------------------------------------------------------------------------

    \22\ Bellair and Hood, 2019. Comprehensive evaluation of the 
flammability and ignitability of HFO-1234ze, R.J. Bellair and L. 
Hood, Process Safety and Environmental Protection 132 (2019) 273-
284. Available online at doi.org/10.1016/j.psep.2019.09.033.
---------------------------------------------------------------------------

    Toxicity and exposure data: Potential health effects of these 
substitutes at lower concentrations include headache, nausea, 
drowsiness, and dizziness. The substitutes may also irritate the skin 
or eyes or cause frostbite. Excessive inhalation of the substitutes may 
also result in an irregular heartbeat, due to cardiac effects. At 
sufficiently high concentrations, they may cause central nervous system 
depression and affect respiration. The substitutes could cause 
asphyxiation if air is displaced by vapors in a confined space. These 
health effects are common to many foam blowing agents.
    The AIHA has established WEELs of 1,000 ppm as an eight-hour time-
weighted average for HFC-152a and 800 ppm for HFO-1234ze(E). Methyl 
formate has an Occupational Safety and Health Administration (OSHA) 
permissible exposure limits (PEL) of 100 ppm on an 8-hr TWA. 
CO2 has an OSHA PEL of 5,000 ppm on an 8-hr TWA, and a 15-
minute recommended short-term exposure limit (STEL) of 30,000 ppm 
established by the National Institute for Occupational Safety and 
Health (NIOSH). EPA anticipates that users will be able to meet the 
AIHA WEELs, OSHA PELs, and NIOSH STEL and address potential health 
risks by following requirements and recommendations in the 
manufacturer's SDSs and other safety precautions common to the foam 
blowing industry.
    Comparison to other substitutes in this end-use: HFO-1234ze(E)/
methyl formate/HFC-152a/CO2/water co-blowing blends have 
ODPs of zero, comparable to all other acceptable substitutes in this 
end-use, such as HFO-1336mzz(Z)/HFC-152a blends, HFC-152a, HFO-
1234ze(E), methyl formate, and CO2.
    The GWPs of the HFO-1234ze(E)/methyl formate/HFC-152a/
CO2/water co-blowing blends, ranging from approximately one 
to 80, are lower than HFC-152a's GWP of 124 and are comparable to or 
lower than those for HFO-1336mzz(Z)/HFC-152a blends (three to 110 
\23\). The worst-case GWPs of the HFO-1234ze(E)/methyl formate/HFC-
152a/CO2/water co-blowing blends are higher than those for 
acceptable alternatives such as HFO-1234ze(E), light saturated 
hydrocarbons C3-C6 and methyl formate, with respective GWPs of less 
than one,\24\ less than one,\25\ and 11,\26\ while the GWP at the low 
end of the range of approximately one is comparable to those acceptable 
alternatives. Based on current information, EPA anticipates that HFO-
1234ze(E), light saturated hydrocarbons C3-C6 and methyl formate are 
not currently being used as the sole blowing agent by any U.S. 
manufacturers in this end-use because the individual chemicals have 
drawbacks such as insufficient vapor pressure, insufficient solubility 
in the polystyrene matrix, or high permeability resulting in low 
thermal resistance (``R-value''); blends such as these HFO-1234ze(E)/
methyl formate/HFC-152a/CO2/water co-blowing blends are 
expected to result in a feasible balance of blowing agent

[[Page 3042]]

properties for adequate or better performance.
---------------------------------------------------------------------------

    \23\ HFO-1336mzz(Z) and HFC-152a have GWPs of about two (WMO, 
2018) and 124 (IPCC, 2007), respectively. If these values are 
weighted by mass percentage, then the blends range in GWP from about 
three to about 110.
    \24\ WMO, 2018.
    \25\ WMO, 2018.
    \26\ WMO, 2018.
---------------------------------------------------------------------------

    Flammability and toxicity risks of the HFO-1234ze(E)/methyl 
formate/HFC-152a/CO2/water co-blowing blends are comparable 
to or lower than flammability and toxicity risks of other available 
substitutes in the same end-use. Some acceptable substitutes in this 
end-use are flammable, like HFC-152a, light saturated hydrocarbons C3-
C6, and methyl formate, while others are non-flammable. Toxicity risks 
can be minimized by use consistent with the AIHA WEELs, OSHA PELs, 
NIOSH STEL, recommendations in the manufacturer's SDSs, and other 
safety precautions common in the foam-blowing industry.
    EPA finds HFO-1234ze(E)/methyl formate/HFC-152a/CO2/
water co-blowing blends acceptable in the XPS end-use because they do 
not pose greater overall environmental and human health risk than other 
available substitutes in the same end-use.

C. Aerosols

1. HCFO-1233yd(Z)
    EPA's decision: EPA finds HCFO-1233yd(Z) acceptable as a substitute 
for use in:

 Aerosol solvents

    HCFO-1233yd(Z) is also known as (Z)-1-Chloro-2,3,3-trifluoropropene 
(CAS Reg. No. 1263679-68-0).
    You may find a copy of the applicant's submission, with CBI 
redacted, providing the required health and environmental information 
for this substitute in this end-use in Docket EPA-HQ-OAR-2003-0118 at 
www.regulations.gov under the name, ``Supporting Materials for Notice 
37 Listing of HCFO-1233yd(Z) in Cleaning Solvents, Aerosol Solvents, 
and Coatings. SNAP Submission Received March 12, 2019.'' EPA performed 
an assessment to examine the health and environmental risks of this 
substitute. This assessment is available in Docket EPA-HQ-OAR-2003-
0118:
     ``Risk Screen on Substitutes in Aerosol Solvents. 
Substitute: HCFO-1233yd(Z).''
    Environmental information: HCFO-1233yd(Z) has an ODP of 0.00003 and 
a GWP of less than 1.\27\ Under CAA regulations (see 40 CFR 51.100(s)) 
defining VOC for the purpose of addressing the development of SIPs to 
attain and maintain the NAAQS, HCFO-1233yd(Z) would be considered a 
VOC. That definition provides that ``any compound of carbon'' which 
``participates in atmospheric photochemical reactions'' is considered a 
VOC unless expressly excluded in that provision based on a 
determination of ``negligible photochemical reactivity.'' The 
manufacturer has petitioned EPA to exclude HCFO-1233yd(Z) from the 
definition of VOC under those regulations. EPA has not yet taken action 
on that petition. This substitute is subject to a Toxic Substance 
Control Act (TSCA) section 5(a)(2) Significant New Use Rule (SNUR).
---------------------------------------------------------------------------

    \27\ Kazuaki Tokuhashi, Tadafumi Uchimaru, Kenji Takizawa, and 
Shigeo Kondo, 2018. Rate Constants for the Reactions of OH Radical 
with the (E)/(Z) Isomers of CF3CF=CHCl and 
CHF2CF=CHCl (J.Phys. Chem. A 2018, 122, 3120-3127) 
(Tokuhashi et al., 2018).
---------------------------------------------------------------------------

    Flammability information: HCFO-1233yd(Z) is not flammable.
    Toxicity and exposure data: Potential health effects of exposure to 
this substitute include drowsiness or dizziness. The substitute may 
also irritate the skin or eyes. The substitute could cause asphyxiation 
if air is displaced by vapors in a confined space. These potential 
health effects are common to many aerosol solvents.
    The manufacturer recommends an acceptable exposure limit (AEL) for 
the workplace of 250 ppm on an 8-hr TWA for HCFO-1233yd(Z). EPA 
anticipates that users will be able to meet the manufacturer's AEL and 
address potential health risks by following requirements and 
recommendations in the manufacturer's SDS, and other safety precautions 
common to the aerosol industry.
    Comparison to other substitutes in this end-use: HCFO-1233yd(Z) has 
an ODP of less than 0.00003, comparable to or less than other listed 
substitutes in this end-use with ODPs ranging from zero to 0.033.
    HCFO-1233yd(Z)'s GWP of less than one is lower than that of other 
acceptable substitutes such as HFE-7200, HFE-347mcc3, HFC-365mfc and 
HFC-4310mee with GWPs ranging from 59 to 1,640. HCFO-1233yd(Z)'s GWP is 
lower than or comparable to the GWPs of other acceptable substitutes 
for aerosol solvents, including acetone, methoxytridecafluoroheptene 
isomers (MPHE), and trans-1-chloro-3,3,3-trifluoroprop-1-ene with GWPs 
ranging from less than one to seven.
    Some acceptable substitutes in this end-use are VOC, like HCFO-
1233yd(Z), while others are excluded from the definition of VOC.
    Flammability and toxicity risks are comparable to or lower than 
flammability and toxicity risks of other available substitutes in the 
same end-use. Toxicity risks can be minimized by use consistent with 
the manufacturer's AEL, industry standards, recommendations in the 
manufacturer's SDS, and other safety precautions common in the aerosol 
industry.
    EPA finds HCFO-1233yd(Z) acceptable in the aerosol solvent end-use 
because it does not pose greater overall environmental and human health 
risk than other available substitutes in the same end-use.

D. Cleaning Solvents

1. HCFO-1233yd(Z)
    EPA's decision: EPA finds HCFO-1233yd(Z) acceptable as a substitute 
for use in:

 Electronics cleaning
 Metals cleaning
 Precision cleaning

    HCFO-1233yd(Z) is also known as (Z)-1-chloro-2,3,3-trifluoropropene 
(CAS Reg. No. 1263679-68-0).
    You may find a copy of the applicant's submission, with CBI 
redacted, providing the required health and environmental information 
for this substitute in this end-use in Docket EPA-HQ-OAR-2003-0118 at 
www.regulations.gov under the name, ``Supporting Materials for Notice 
37 Listing of HCFO-1233yd(Z) in Cleaning Solvents, Aerosol Solvents, 
and Coatings. SNAP Submission Received March 12, 2019.'' EPA performed 
an assessment to examine the health and environmental risks of this 
substitute. This assessment is available in Docket EPA-HQ-OAR-2003-
0118:
     ``Risk Screen on Substitutes in Electronics Cleaning, 
Metals Cleaning, and Precision Cleaning. Substitute: HCFO-1233yd(Z).''
    Environmental information: The environmental information for this 
substitute is set forth in the ``Environmental information'' section in 
listing in I.C.1. above.
    Flammability information: HCFO-1233yd(Z) is not flammable.
    Toxicity and exposure data: The toxicity information for this 
substitute is set forth in the ``Toxicity and exposure data'' section 
in listing I.C.1. above.
    Comparison to other substitutes in these end-uses: HCFO-1233yd(Z) 
has an ODP of less than 0.00003, comparable to or less than other 
listed substitutes in the metals cleaning, electronics cleaning, and 
precision cleaning end-uses with ODPs ranging from zero to 0.033.
    HCFO-1233yd(Z)'s GWP of less than 1 is lower than that of other 
acceptable substitutes such as HFE-7200, HFE-7100, HFC-365mfc and HFC-
4310mee with GWPs ranging from 59 to 1,640. HCFO-1233yd(Z)'s GWP is 
lower than or comparable to the GWPs of other acceptable substitutes 
for cleaning solvents, including acetone, MPHE, and

[[Page 3043]]

trans-1-chloro-3,3,3-trifluoroprop-1-ene with GWPs ranging from less 
than one to seven.
    Some acceptable substitutes in these end-uses are VOC, like HCFO-
1233yd(Z), while others are excluded from the definition of VOC.
    Flammability and toxicity risks are comparable to or lower than 
flammability and toxicity risks of other available substitutes in the 
same end-use. Toxicity risks can be minimized by use consistent with 
the manufacturer's AEL, recommendations in the manufacturer's SDS, and 
other safety precautions common in the cleaning solvents industry.
    EPA finds HCFO-1233yd(Z) acceptable in the end-uses listed above 
because it does not pose greater overall environmental and human health 
risk than other available substitutes in the same end-uses.

E. Adhesives, Coatings, and Inks

1. HCFO-1233yd(Z)
    EPA's decision: EPA finds HCFO-1233yd(Z) acceptable as a substitute 
for use as a carrier solvent in:

 Coatings

    HCFO-1233yd(Z) is also known as (Z)-1-chloro-2,3,3-trifluoropropene 
(CAS Reg. No. 1263679-68-0).
    You may find a copy of the applicant's submission, with CBI 
redacted, providing the required health and environmental information 
for this substitute in this end-use in Docket EPA-HQ-OAR-2003-0118 at 
www.regulations.gov under the name, ``Supporting Materials for Notice 
37 Listing of HCFO-1233yd(Z) in Cleaning Solvents, Aerosol Solvents, 
and Coatings. SNAP Submission Received March 12, 2019.'' EPA performed 
an assessment to examine the health and environmental risks of this 
substitute. This assessment is available in Docket EPA-HQ-OAR-2003-
0118:
     ``Risk Screen on Substitutes in Coatings. Substitute: 
HCFO-1233yd(Z).''
    Environmental information: The environmental information for this 
substitute is set forth in the ``Environmental information'' section in 
listing I.C.1., above.
    Flammability information: HCFO-1233yd(Z) is not flammable.
    Toxicity and exposure data: The toxicity information for this 
substitute is set forth in the ``Toxicity and exposure data'' section 
in listing I.C.1., above.
    Comparison to other substitutes in these end-uses: HCFO-1233yd(Z) 
has an ODP of less than 0.00003, comparable to or less than other 
listed substitutes in this end-use with ODPs ranging from zero to 
0.00034.
    For coatings, HCFO-1233yd(Z)'s GWP of less than one is lower than 
that of other acceptable substitutes such as HFE-7200 and HFE-7100 with 
GWPs ranging from 59 to 297. HCFO-1233yd(Z)'s GWP is lower than or 
comparable to the GWPs of other acceptable substitutes for coatings, 
including acetone, MPHE, and trans-1-chloro-3,3,3-trifluoroprop-1-ene 
with GWPs ranging from less than one to seven. Some acceptable 
substitutes in this end-use are VOC, like HCFO-1233yd(Z), while others 
are excluded from the definition of VOC.
    Flammability and toxicity risks are comparable to or lower than 
flammability and toxicity risks of other available substitutes in the 
same end-use. Toxicity risks can be minimized by use consistent with 
the manufacturer's AEL, recommendations in the manufacturer's SDS, and 
other safety precautions common in the coatings industry.
    EPA finds HCFO-1233yd(Z) acceptable in the coatings end-use because 
it does not pose greater overall environmental and human health risk 
than other available substitutes in the same end-use.

List of Subjects in 40 CFR Part 82

    Environmental protection, Administrative practice and procedure, 
Air pollution control, Reporting and recordkeeping requirements.

Hans Christopher Grundler,
Director, Office of Atmospheric Programs.

Appendix A: Summary of Decisions for New Acceptable Substitutes

                                       Refrigeration and Air Conditioning
----------------------------------------------------------------------------------------------------------------
           End-use                Substitute            Decision                 Further information \1\
----------------------------------------------------------------------------------------------------------------
Cold Storage Warehouses (new   HCFO-1233zd(E)..  Acceptable...........  HCFO-1233zd(E) is also known as trans-1-
 equipment only).                                                        chloro-3,3,3-trifluoroprop-1-ene
                                                                         (Chemical Abstracts Service Registry
                                                                         Number [CAS Reg. No.] 102687-65-0).
                                                                        HCFO-1233zd(E) has an ozone depletion
                                                                         potential (ODP) of less than 0.0004 and
                                                                         a 100-year integrated global warming
                                                                         potential (GWP) of about 3.7.
                                                                        HCFO-1233zd(E) is nonflammable.
                                                                        The Workplace Environmental Exposure
                                                                         Limits (WEEL) committee of the
                                                                         Occupational Alliance for Risk Science
                                                                         (OARS) has established a WEEL of 800
                                                                         ppm as an eight-hour time-weighted
                                                                         average (8-hr TWA) for HCFO-1233zd(E).
Ice Skating Rinks (new         HCFO-1233zd(E)..  Acceptable...........  HCFO-1233zd(E) is also known as trans-1-
 equipment only).                                                        chloro-3,3,3-trifluoroprop-1-ene (CAS
                                                                         Reg. No. 102687-65-0).
                                                                        HCFO-1233zd(E) has an ODP of less than
                                                                         0.0004 and a GWP of about 3.7.
                                                                        HCFO-1233zd(E) is nonflammable.
                                                                        OARS has established a WEEL of 800 ppm
                                                                         on an 8-hr TWA for HCFO-1233zd(E).
Industrial Process Air         HCFO-1233zd(E)..  Acceptable...........  HCFO-1233zd(E) is also known as trans-1-
 Conditioning (new equipment                                             chloro-3,3,3-trifluoroprop-1-ene (CAS
 only).                                                                  Reg. No. 102687-65-0).
                                                                        HCFO-1233zd(E) has an ODP of less than
                                                                         0.0004 and a GWP of about 3.7.
                                                                        HCFO-1233zd(E) is nonflammable.
                                                                        OARS has established a WEEL of 800 ppm
                                                                         on an 8-hr TWA for HCFO-1233zd(E).
----------------------------------------------------------------------------------------------------------------
\1\ See recommendations in the manufacturer's SDS and guidance for all listed refrigerants.


                                               Foam Blowing Agents
----------------------------------------------------------------------------------------------------------------
           End-use                Substitute            Decision                 Further information \1\
----------------------------------------------------------------------------------------------------------------
Extruded Polystyrene:          Blends of 10 to   Acceptable...........  This substitute is blends of 10 to 90
 Boardstock and Billet.         90 percent HFO-                          percent HFO-1234ze(E) by weight and the
                                1234ze(E) by                             remainder HCFO-1233zd(E). HFO-1234ze(E)
                                weight and the                           is also called 1,3,3,3-
                                remainder HCFO-                          tetrafluoropropene(E), or trans-1,3,3,3-
                                1233zd(E).                               tetrafluoropropene (Chemical Abstracts
                                                                         Service Registry Number [CAS Reg. No.]
                                                                         29118-24-9). HCFO-1233zd(E) is also
                                                                         called trans-1-chloro-3,3,3-trifluoro-
                                                                         prop-1-ene (CAS Reg. No. 102687-65-0).

[[Page 3044]]

 
                                                                        HFO-1234ze(E) has a 100-year integrated
                                                                         global warming potential (GWP) of less
                                                                         than one.
                                                                        HCFO-1233zd(E) has an ozone depletion
                                                                         potential (ODP) of less than 0.0004 and
                                                                         a GWP of 3.7. The blends have an ODP
                                                                         ranging from less than 0.0004 to less
                                                                         than 0.00004 and range in GWP from
                                                                         about 1.3 to about 3.4.
                                                                        HFO-1234ze(E) is not flammable at
                                                                         standard temperature and pressure,
                                                                         however, however, at higher
                                                                         temperatures, such as the temperatures
                                                                         typical for extruding extruded
                                                                         polystyrene: boardstock and billet
                                                                         (XPS), HFO-1234ze(E) may be flammable,
                                                                         particularly at higher humidity levels.
                                                                         HCFO-1233zd(E) is non-flammable.
                                                                        The American Industrial Hygiene
                                                                         Association (AIHA) has established a
                                                                         Workplace Environmental Exposure Limit
                                                                         (WEEL) of 800 ppm as an eight-hour time-
                                                                         weighted average (8-hr TWA) for HFO-
                                                                         1234ze(E), and the Occupational
                                                                         Alliance for Risk Sciences (OARS) has
                                                                         established a WEEL of 800 ppm as an 8-
                                                                         hr TWA for HCFO-1233zd(E).
Extruded Polystyrene:          Blends of 10 to   Acceptable...........  This substitute is blends of 10 to 90
 Boardstock and Billet.         90 percent HFO-                          Percent HFO-1234ze(E) by weight and the
                                1234ze(E) by                             remainder HFC-152a. HFO-1234ze(E) is
                                weight and the                           also called 1,3,3,3-tetrafluoropropene
                                remainder HFC-                           (E), or trans-1,3,3,3-
                                152a.                                    tetrafluoropropene (CAS Reg. No. 29118-
                                                                         24-9). HFC-152a is also called 1,1-
                                                                         difluoroethane (CAS Reg. No. 75-37-6).
                                                                        The blend and its components have an ODP
                                                                         of zero. HFO-1234ze(E) has a GWP of
                                                                         less than one and HFC-152a has a GWP of
                                                                         124. The blends range in GWP from about
                                                                         13 to about 112.
                                                                        HFO-1234ze(E) is not flammable at
                                                                         standard temperature and pressure,
                                                                         however, at higher temperatures, such
                                                                         as the temperatures typical for
                                                                         extruding XPS, HFO-1234ze(E) may be
                                                                         flammable, particularly at higher
                                                                         humidity levels. HFC-152a is flammable
                                                                         at standard temperature and pressure.
                                                                        The AIHA has established a WEEL of 1,000
                                                                         ppm for HFC-152a and a WEEL of 800 ppm
                                                                         for HFO-1234ze(E), both as an 8-hr TWA.
Extruded Polystyrene:          Blends of 0-100%  Acceptable...........  This substitute is blends of 0-100% HFO-
 Boardstock and Billet.         HFO-1234ze(E),                           1234ze(E), 0-70% methyl formate, 0-60%
                                0-70% Methyl                             HFC-152a, 0-60% CO2 and 0-60% water.
                                Formate, 0-60%                           HFO-1234ze(E) is also called 1,3,3,3-
                                HFC-152a, 0-60%                          tetrafluoropropene (E), or trans-
                                CO2 and 0-60%                            1,3,3,3-tetrafluoropropene (CAS Reg.
                                Water.                                   No. 29118-24-9). Methyl formate is also
                                                                         called methyl methanoate or formic
                                                                         acid, methyl ester (CAS Reg. No. 107-31-
                                                                         3). HFC-152a is also called 1,1-
                                                                         difluoroethane, has CAS Reg. No. 75-37-
                                                                         6. CO2 has CAS Reg. No. 124-38-9, and
                                                                         water has CAS Reg. No. 7732-18-5.
                                                                        HFO-1234ze(E) and water have GWPs of
                                                                         less than one, CO2 has a GWP of one,
                                                                         methyl formate has a GWP of 11, and HFC-
                                                                         152a has a GWP of 124. The blends range
                                                                         in GWP from approximately one to 80.
                                                                        HFO-1234ze(E) is not flammable at
                                                                         standard temperature and pressure;
                                                                         however, at higher temperatures, such
                                                                         as the temperatures typical for
                                                                         extruding XPS, HFO-1234ze(E) may be
                                                                         flammable, particularly at higher
                                                                         humidity levels. HFC-152a and methyl
                                                                         formate are flammable at standard
                                                                         temperature and pressure.
                                                                        The AIHA has established a WEEL of 1,000
                                                                         ppm for HFC-152a and a WEEL of 800 ppm
                                                                         for HFO-1234ze(E), both as an 8-hr TWA.
----------------------------------------------------------------------------------------------------------------
\1\ See recommendations in the manufacturer's SDS and guidance for all listed foam blowing agents.


                                                Cleaning Solvents
----------------------------------------------------------------------------------------------------------------
           End-use                Substitute            Decision                 Further information \1\
----------------------------------------------------------------------------------------------------------------
Electronics cleaning, metals   HCFO-1233yd(Z)..  Acceptable...........  HCFO-1233yd(Z) is also known as (Z)-1-
 cleaning, precision cleaning.                                           chloro-2,3,3-trifluoropropene (CAS Reg.
                                                                         No. 1263679-68-0).
                                                                        HCFO-1233yd(Z) has an ozone depletion
                                                                         potential (ODP) of 0.00003 and a global
                                                                         warming potential (GWP) of less than 1.
                                                                        This compound is nonflammable.
                                                                        The manufacturer recommends an
                                                                         acceptable exposure limit (AEL) for the
                                                                         workplace for HCFO-1233yd(Z) of 250 ppm
                                                                         on an eight-hour time-weighted average
                                                                         (8-hr TWA).
                                                                        This substitute is subject to a Toxic
                                                                         Substances Control Act (TSCA) section
                                                                         5(a)(2) Significant New Use Rule
                                                                         (SNUR).
----------------------------------------------------------------------------------------------------------------
\1\ See recommendations in the manufacturer's SDS and guidance for all listed cleaning solvents.


                                                    Aerosols
----------------------------------------------------------------------------------------------------------------
           End-use                Substitute            Decision                 Further information \1\
----------------------------------------------------------------------------------------------------------------
Aerosol solvents.............  HCFO-1233yd(Z)..  Acceptable...........  HCFO-1233yd(Z) is also known as (Z)-1-
                                                                         chloro-2,3,3-trifluoropropene (CAS Reg.
                                                                         No. 1263679-68-0).
                                                                        HCFO-1233yd(Z) has an ozone depleting
                                                                         potential (ODP) of 0.00003 and a global
                                                                         warming potential (GWP) of less than 1.
                                                                        This compound is nonflammable.
                                                                        The manufacturer recommends an
                                                                         acceptable exposure limit (AEL) for the
                                                                         workplace for HCFO-1233yd(Z) of 250 ppm
                                                                         on an eight-hour time-weighted average
                                                                         (8-hr TWA).
                                                                        This substitute is subject to a Toxic
                                                                         Substances Control Act (TSCA) section
                                                                         5(a)(2) Significant New Use Rule
                                                                         (SNUR).
----------------------------------------------------------------------------------------------------------------
\1\ See recommendations in the manufacturer's SDS and guidance for all listed aerosols.


[[Page 3045]]


                                          Adhesives, Coatings, and Inks
----------------------------------------------------------------------------------------------------------------
           End-use                Substitute            Decision                 Further information \1\
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Coatings.....................  HCFO-1233yd(Z)..  Acceptable...........  HCFO-1233yd(Z) is also known as (Z)-1-
                                                                         chloro-2,3,3-trifluoropropene (CAS Reg.
                                                                         No. 1263679-68-0).
                                                                        HCFO-1233yd(Z) has an ozone depleting
                                                                         potential (ODP) of 0.00003 and a global
                                                                         warming potential (GWP) of less than 1.
                                                                        This compound is nonflammable.
                                                                        The manufacturer recommends an
                                                                         acceptable exposure limit (AEL) for the
                                                                         workplace for HCFO-1233yd(Z) of 250 ppm
                                                                         on an eight-hour time-weighted average
                                                                         (8-hr TWA).
                                                                        This substitute is subject to a Toxic
                                                                         Substance Control Act (TSCA) section
                                                                         5(a)(2) Significant New Use Rule
                                                                         (SNUR).
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\1\ See recommendations in the manufacturer's SDS and guidance for all listed carrier solvents for adhesives,
  coatings, and inks.

[FR Doc. 2022-00998 Filed 1-19-22; 8:45 am]
BILLING CODE 6560-50-P