99720 Federal Register / Vol. 89, No. 238 / Wednesday, December 11, 2024 / Rules and Regulations 

1 IPCC, 2007: Climate Change 2007: The Physical 

Science Basis. Contribution of Working Group I to 

the Fourth Assessment Report of the 

Intergovernmental Panel on Climate Change 

[Solomon, S., Qin, D., Manning, M., Chen, Z., 

Marquis, M., Averyt, K.B., Tignor M., and Miller, 

H.L. (eds.)]. Cambridge University Press, 

Cambridge, United Kingdom and New York, NY, 

USA. Available at: https://www.ipcc.ch/ 

publications_and_data/ar4/wg1/en/contents.html. 

2The IPCC, 2007 100-year GWP values are 

consistent with the exchange values for the 

regulated HFCs listed in subsection (c) of the AIM 

Act and with the GWPs in Annex F of the Montreal 

Protocol. 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 82 

[EPA–HQ–OAR–2003–0118; FRL–12145–01– 

OAR] 

RIN 2060–AG12 

Protection of Stratospheric Ozone: 

Determination 39 for the Significant 

New Alternatives Policy Program 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Determination of acceptability. 

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 four 

substitutes as acceptable additional 

substitutes for use in the refrigeration 

and air conditioning and foam blowing 

sectors. 

DATES: This determination is applicable 

on December 11, 2024. 

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 https://

www.regulations.gov. Although listed in 

the index, some information is not 

publicly available, e.g., confidential 

business information (CBI) or other 

information whose disclosure is 

restricted by statute. Publicly available 

docket materials are available either 

electronically at https://

www.regulations.gov or in hard copy at 

the EPA Docket Center (EPA/DC), 

(Docket Nos. A–91–42 and EPA–HQ– 

OAR–2003–0118), 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 and 

Radiation Docket is (202) 566–1742. The 

Docket Center’s hours of operations are 

8:30 a.m.–4:30 p.m., Monday–Friday 

(except Federal Holidays). For further 

information on the EPA Docket Center 

services and the current status, please 

visit online at https://www.epa.gov/ 

dockets. 

FOR FURTHER INFORMATION CONTACT: 

Nathaniel Burola, Stratospheric 

Protection Division, Office of 

Atmospheric Protection (Mail Code 

6205A), U.S. Environmental Protection 

Agency, 1200 Pennsylvania Avenue 

NW, 20460; telephone number: 202– 

564–2883; email address: 

Burola.Nathaniel@epa.gov. 

Table of Contents 

I. Listing of New Acceptable Substitutes 

A. Refrigeration and Air Conditioning 

1. R–471A 

2. R–480A 

3. R–513A 

B. Foam Blowing 

1. Extruded Polystyrene (XPS) Blowing 

Agent Blends of 0 to 90 Percent HFO– 

1336mzz(Z), 0 to 90 Percent HFO– 

1234ze(E), 0 to 75 Percent HFC–152a, 

and 0 to 90 Percent CO2

Appendix A: Summary of Decisions for New 

Acceptable Substitutes 

SUPPLEMENTARY INFORMATION: 

I. Listing of New Acceptable Substitutes 

This action is listing as acceptable 

additional substitutes for use in the 

refrigeration and air conditioning and 

foam blowing sectors. This action 

presents EPA’s most recent decisions 

under the Significant New Alternatives 

Policy (SNAP) program to list as 

acceptable several substitutes in 

different end-uses. The new substitutes 

are: 

• R–471A in retail food refrigeration, 

industrial process refrigeration, and 

cold storage warehouses (retrofit 

equipment only); 

• R–480A in cold storage warehouses, 

commercial ice machines, positive 

displacement chillers, refrigerated 

transport, and water coolers (retrofit 

equipment only); 

• R–513A in residential and light 

commercial air conditioning and heat 

pumps—self-contained units (new 

equipment only); 

• XPS foam blowing agent blends of 

0 to 90 percent hydrofluoroolefin 

(HFO)–1336mzz(Z), 0 to 90 percent 

HFO–1234ze(E), 0 to 75 percent 

hydrofluorocarbon (HFC)–152a, and 0 to 

90 percent carbon dioxide (CO2) in 

polystyrene: extruded boardstock and 

billet. 

Listing decisions in the end-uses in 

this document do not prejudge EPA’s 

listings of these substitutes for other 

end-uses. For additional information on 

SNAP, visit the SNAP website at https:// 

www.epa.gov/snap. The full lists of 

acceptable substitutes for ozonedepleting substances (ODS) in the 

industrial sectors covered by the SNAP 

program are available at https://

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 (59 FR 13044; March 18, 

1994). The regulations are codified at 40 

CFR part 82, subpart G. SNAP decisions 

and the appropriate Federal Register 

citations are available at: https://

www.epa.gov/snap/snap-regulations. 

Under the SNAP program, EPA may list 

a substitute as acceptable for specified 

end-uses where the Agency has 

reviewed the substitute and found no 

reason to restrict or prohibit its use. 

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. 

This document discusses each 

substitute listing in detail and 

summarizes the results of EPA’s 

assessment of the human health and 

environmental risks posed by each 

substitute. EPA’s evaluation applies the 

criteria in 40 CFR 82.180(a)(7), 

including atmospheric effects and 

related health and environmental 

effects, ecosystem risks, occupational 

risks, consumer risks, flammability, and 

cost and availability of the substitute. 

EPA evaluates these criteria in risk 

screens, or technical documents that 

evaluate risks to human health and the 

environment from substitutes in specific 

end-uses, including comparisons to 

other available substitutes and 

evaluations against relevant thresholds 

of risk starting with protective 

assumptions. The risk screens cited in 

this document include evaluation of 

atmospheric effects, toxicity data, 

exposure assessments, flammability, 

and other environmental impacts such 

as ecotoxicity and local air quality 

impacts. You can find more information 

on the criteria used in the evaluation of 

substitutes in the SNAP program at 

https://www.epa.gov/snap/snapregulations. 

In this document, EPA determined the 

global warming potential (GWP) for a 

chemical or blend using the 100-year 

GWP values from the Intergovernmental 

Panel on Climate Change’s (IPCC) 

Fourth Assessment Report (AR4) 1 for 

substances or components of blends if 

included.2 Note that Annex F to the 

Montreal Protocol on Substances that 

Deplete the Ozone Layer lists GWPs for 

HFCs that are numerically equivalent to 


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3Annex F of the Montreal Protocol is available at: 

https://ozone.unep.org/treaties/montreal-protocol/ 

articles/annex-f-controlled-substances. 

4WMO, Scientific Assessment of Ozone 

Depletion: 2022, GAW Report No. 278, 509 pp.; 

WMO: Geneva, 2022. Available at: https://

ozone.unep.org/system/files/documents/ScientificAssessment-of-Ozone-Depletion-2022.pdf. (WMO, 

2022). 

5For example, there may be restrictions or 

prohibitions in regulations issued under section 610 

of the CAA at 40 CFR part 82 subpart C for 

nonessential products containing ODS, under the 

Toxic Substances Control Act, under the 

Occupation Safety and Health Act, and under state 

or local laws and regulations that warrant 

consideration. 

6WMO, 2022. 

7WMO, 2022. 

8Annex F to the Montreal Protocol. 

9ASTM, E681. Standard Test Method for 

Concentration Limits of Flammability of Chemicals 

(Vapors and Gases). 

the AR4 values.3 These HFC 100-year 

GWP values are also numerically 

equivalent to the exchange values listed 

in the American Innovation and 

Manufacturing Act of 2020 (hereafter 

referred to as ‘‘the AIM Act’’). If no GWP 

is provided in AR4 for a substance, the 

SNAP program is using the 100-year 

GWP listed in World Meteorological 

Organization (WMO), 2022.4 To 

calculate the GWP of blends of 

chemicals, such as the listed refrigerant 

blends, this document weights the GWP 

of each component of the blend by its 

mass percentage. This method of 

calculating GWPs is consistent with the 

method used to calculate GWPs in the 

October 2023 Technology Transitions 

Rule as codified at 40 CFR 84.64. 

Under section 612 of the Clean Air 

Act (CAA), the SNAP program reviews 

substitutes using a comparative risk 

framework in different industrial 

sectors. In making listing decisions, EPA 

considers overall risk to human health 

and the environment. As a general 

matter, the substitutes being added 

through this action to the acceptable 

lists have a similar or lower risk than 

other substitutes already listed as 

acceptable in those end-uses. However, 

certain substitutes may have a higher 

risk than certain other substitutes 

already listed as acceptable or 

acceptable subject to restrictions. In 

such cases, those already-listed 

alternatives have other factors that limit 

their use in some situations within a 

particular end-use. 

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 CAA. Although users 

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 enduse, 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. 

It should be noted that a substitute 

listed as acceptable under the SNAP 

program may also be subject to 

requirements or limitations under other 

statutory or regulatory provisions. For 

example, there are relevant regulations 

under subsection (i) of the AIM Act that 

restrict the use of certain HFCs in a 

variety of sectors and subsectors. See 88 

FR 73098 (October 24, 2023). 

Consequently, if a substitute listed as 

acceptable under the SNAP program is 

also subject to limitations on its use 

under other regulations, it may not be 

permitted for use in accordance with 

those other regulations. Those intending 

to use a substitute listed as acceptable 

under the SNAP program may need to 

consider restrictions under subsection 

(i) of the AIM Act, as well as other 

relevant authorities, and must also be 

followed.5

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 the docket 

(EPA–HQ–OAR–2003–0118) at https://

www.regulations.gov. 

A. Refrigeration and Air Conditioning 

1. R–471A 

EPA’s decision: EPA finds R–471A 

acceptable as a substitute for use in: 

• Cold storage warehouses (retrofit 

equipment only); 

• Industrial process refrigeration 

(retrofit equipment only); 

• Retail food refrigeration— 

Refrigerated food processing and 

dispensing equipment (retrofit 

equipment only); 

• Retail food refrigeration—Remote 

condensing units (retrofit equipment 

only); 

• Retail food refrigeration— 

Supermarket systems (retrofit 

equipment only). 

R–471A, marketed under the trade 

name Solstice® N71, is a weighted blend 

of 78.7 percent HFO–1234ze(E), also 

known as trans-1,3,3,3-tetrafluoroprop1-ene (Chemical Abstracts Service 

Registry Number [CAS Reg. No.] 29118– 

24–9); 17.0 percent HFO–1336mzz(E), 

also known as trans-1,1,1,4,4,4- 

hexafluoro-2-butene (CAS Reg. No. 

66711–86–2); and 4.3 percent HFC– 

227ea, which is also known as 

1,1,1,2,3,3,3-heptafluoropropane (CAS 

Reg. No. 431–89–0). 

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 the docket 

(EPA–HQ–OAR–2003–0118) at https://

www.regulations.gov under the name, 

‘‘Supporting Materials for Notice 39 

Listing of R–471A in Refrigeration and 

Air Conditioning. SNAP Submission 

Received September 15, 2023.’’ EPA 

performed assessments to examine the 

health and environmental risks of this 

substitute, and the results are 

summarized below. These assessments 

are available in the docket EPA–HQ– 

OAR–2003–0118: 

• ‘‘Risk Screen on Substitutes in 

Retail Food Refrigeration (Retrofit 

Equipment) Substitute: R–471A 

(Solstice® N71).’’ 

• ‘‘Risk Screen on Substitutes in 

Industrial Process Refrigeration and 

Cold Storage Warehouses (Retrofit 

Equipment) Substitute: R–471A 

(Solstice® N71).’’ 

Environmental information: R–471A 

has an ozone depletion potential (ODP) 

of 0. Its components, HFO–1234ze(E), 

HFO–1336mzz(E), and HFC–227ea, have 

GWPs of 1,6 26,7 and 3,220,8

respectively. When these values are 

weighted by mass percentage of the 

blend, R–471A has a GWP of about 144. 

The components of R–471A are 

excluded from the EPA’s regulatory 

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 otherwise knowingly 

releasing this refrigerant blend is 

limited by the venting prohibition under 

section 608(c)(2) of the CAA, codified in 

EPA regulations at 40 CFR 82.154(a). 

Flammability information: The 

component HFO–1234ze(E) has lower 

flammability as defined using the 

standard test method American Society 

of Testing and Materials (ASTM) E681.9

The other two components of R–471A 

are not flammable using the same 


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10ASHRAE Standard 34–2022: Designation and 

Safety Classification of Refrigerants. (ASHRAE, 

2022). 

11ASHRAE, 2022. 

12Trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO– 

1336mzz–E) (2018). Toxicology and Industrial 

Health. 2019; 35(3):204–210. doi:10.1177/ 

0748233719825529. 

13ASHRAE, 2022. 

14ASHRAE 15. Safety Standard for Refrigeration 

Systems. 

15The October 2023 Technology Transitions Rule 

does not restrict the use of HFCs (i.e., establish 

GWP limits) in retrofit applications (See 88 FR 

73127). 

method. R–471A is not flammable as 

formulated, in the worst-case 

formulation for flammability (WCF) and 

the worst-case of fractionation for 

flammability (WCFF). The American 

Society of Heating, Refrigerating, and 

Air-Conditioning Engineers (ASHRAE) 

has assigned R–471A a flammability 

class of ‘‘1,’’ meaning it does not 

propagate a flame under standard test 

conditions.10

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 

in the case of rapid evaporation of the 

liquid. The substitute could cause 

asphyxiation if air is displaced by 

vapors in a confined space. Excessive 

exposure may cause central nervous 

system effects including drowsiness and 

dizziness. Excessive exposure may also 

cause cardiac arrhythmia. These 

potential health effects are common to 

many refrigerants. 

ASHRAE has adopted an occupational 

exposure limit (OEL) for the blend of 

710 ppm 11 12 on an eight-hour timeweighted average (8-hr TWA) for HFO– 

1336mzz(E), the American Industrial 

Hygiene Association (AIHA) has 

established a WEEL of 1,000 ppm (8-hr 

TWA) for HFC–227ea, and ASHRAE has 

adopted an OEL of 800 ppm (8-hr TWA) 

for HFO–1234ze(E).13 EPA anticipates 

that users will be able to meet these 

workplace guidance limits and address 

potential health risks by following 

recommendations in the manufacturer’s 

safety data sheet (SDS), ASHRAE 

Standard 15,14 other industry standards, 

and other safety precautions common to 

the refrigeration and air conditioning 

industry. 

Comparison to other substitutes in 

these end-uses: R–471A has an ODP of 

0, comparable to or less than other listed 

substitutes in retrofits for these end-uses 

with ODPs ranging from 0 to less than 

0.0004. 

As a retrofit for supermarket systems, 

remote condensing units, and 

refrigerated food processing and 

dispensing equipment, R–471A with a 

GWP of 144 is lower than that of all 

other acceptable substitutes such as R– 

450A which has a GWP of 601; R–513A 

with a GWP of 630; R–448A with a GWP 

of 1,386; R–449A with a GWP of 1,396; 

R–449B with a GWP of 1,412; R–407C 

with a GWP of 1,770; R–407F with a 

GWP of 1,825; and R–407A with a GWP 

of 2,107. 

For retrofits in industrial process 

refrigeration, R–471A’s GWP of 144 is 

lower than that of other acceptable 

substitutes such as HFC–134a which has 

a GWP of 1,430; R–407C with a GWP of 

1,770; and R–407F with a GWP of 1,825. 

Other alternatives in this sector have a 

lower GWP than R–471A such as CO2

with a GWP of 1 and R–290 (propane) 

with a GWP of 3. There may be 

situations in which lower-GWP options 

may not be feasible for certain 

retrofitted industrial process 

refrigeration equipment. For example, 

CO2, which has a GWP of 1 is a highpressure refrigerant and cannot be used 

as a retrofit for low-pressure refrigerant 

systems. R–471A is a low-pressure 

refrigerant, making it more technically 

feasible to retrofit systems that use 

similar low-pressure refrigerants. R–290 

is an A3, highly flammable refrigerant 

and may not be feasible for certain 

retrofitted industrial process 

refrigeration equipment where 

flammability is a concern. 

Further, refrigerants offer cooling 

within a specific temperature range. 

Adding R–471A to the list of available 

substitutes in industrial process 

refrigeration systems may offer a 

refrigerant that achieves a specific 

cooling temperature that other retrofit 

alternatives with lower GWPs cannot 

achieve.15 For retrofits of cold storage 

warehouses, R–471A’s GWP of 144 is 

lower than that of all other acceptable 

substitutes such as R–450A with a GWP 

of 601; R–513A with a GWP of 630; 

HFC–134a with a GWP of 1,430; R–407C 

with a GWP of 1,770; and R–407F with 

a GWP of 1,825. 

Flammability and toxicity risks are 

comparable to or lower than 

flammability and toxicity risks of other 

available substitutes in the same retrofit 

end-uses. Toxicity risks can be 

minimized by use consistent with the 

AIHA and OARS WEELs, ASHRAE 

OELs and ASHRAE 15, other industry 

standards, recommendations in the 

manufacturer’s SDS, and other safety 

precautions common in the refrigeration 

and air conditioning industry. 

Based on the considerations described 

above, EPA finds R–471A acceptable as 

a retrofit refrigerant for the following 

end-uses: cold storage warehouses, 

industrial process refrigeration, and 

retail food refrigeration (including 

supermarket systems, remote 

condensing units, and refrigerated food 

processing and dispensing equipment), 

because it does not pose greater overall 

environmental and human health risk 

than other available substitutes in the 

same end-uses. 

2. R–480A 

EPA’s decision: EPA finds R–480A 

acceptable as a substitute for use in: 

• Cold storage warehouses (retrofit 

equipment only); 

• Commercial ice machines (retrofit 

equipment only); 

• Positive displacement chillers 

(retrofit equipment only); 

• Refrigerated transport (retrofit 

equipment only); 

• Water coolers (retrofit equipment 

only). 

R–480A, marketed under the trade 

name RS–20, is a weighted blend of 5 

percent CO2 (CAS Reg. No. 124–38–9), 

86 percent HFO–1234ze(E), also known 

as trans-1,3,3,3-tetrafluoroprop-1-ene 

(CAS Reg. No. 29118–24–9), and 9 

percent HFC–227ea, also known as 

1,1,1,2,3,3,3-heptafluoropropane (CAS 

Reg. No. 431–89–0). 

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 the docket 

(EPA–HQ–OAR–2003–0118) at https://

www.regulations.gov under the name, 

‘‘Supporting Materials for Notice 39 

Listing of R–480A in Refrigeration and 

Air Conditioning. SNAP Submission 

Received May 16, 2024.’’ EPA 

performed assessments to examine the 

health and environmental risks of this 

substitute, and the results are 

summarized below. These assessments 

are available in the docket EPA–HQ– 

OAR–2003–0118: 

• ‘‘Risk Screen on Substitutes in Cold 

Storage Warehouses (Retrofit 

Equipment). Substitute: R–480A (RS– 

20).’’ 

• ‘‘Risk Screen on Substitutes in 

Commercial Ice Machines (Retrofit 

Equipment). Substitute: R–480A (RS– 

20).’’ 

• ‘‘Risk Screen on Substitutes in 

Chillers (Retrofit Equipment). 

Substitute: R–480A (RS–20).’’ 

• ‘‘Risk Screen on Substitutes in 

Refrigerated Transport (Retrofit 

Equipment). Substitute: R–480A (RS– 

20).’’ 

• ‘‘Risk Screen on Substitutes in 

Water Coolers (Retrofit Equipment). 

Substitute: R–480A (RS–20).’’ 

Environmental information: R–480A 

has an ODP of 0. This blend consists of 


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16 IPCC, 2007. 

17WMO, 2022. 

18Annex F to the Montreal Protocol. 

19ASHRAE, 2022, Addendum h. 

20ASHRAE, 2022. 

21WMO, 2022. 

22This value is calculated by weighting the GWPs 

of HFO–1336mzz(Z) (2) and 1,2-dichloroethene(Z) 

(1) from WMO, 2022 by the mass percentages of the 

blend components of 74.7 percent and 25.3 percent, 

respectively. 

23Annex F to the Montreal Protocol. 

24WMO, 2022. 

CO2 with a GWP of 1,16 HFO–1234ze(E) 

with a GWP of 1,17 and HFC–227ea with 

a GWP of 3,220.18 Weighting these 

values by mass percentage results in a 

GWP of 291 for R–480A. The 

components of R–480A are excluded 

from EPA’s regulatory definition of VOC 

under CAA regulations (see 40 CFR 

51.100(s)) addressing the development 

of SIPs to attain and maintain the 

NAAQS. Knowingly venting or 

otherwise knowingly releasing this 

refrigerant blend is limited by the 

venting prohibition under CAA section 

608(c)(2), codified at 40 CFR 82.154(a). 

Flammability information: The 

component HFO–1234ze(E) has lower 

flammability as defined using the 

standard test method ASTM E681, while 

the other two components of R–480A 

are not flammable using the same 

method. R–480A is not flammable as 

formulated, in the WCF and the WCFF. 

ASHRAE has assigned R–480A a 

flammability class of ‘‘1,’’ meaning it 

does not propagate a flame under 

standard test conditions. 

Toxicity and exposure data: The 

substitute may be hazardous if 

inhalation, skin contact, or eye contact 

with the substitute occurs at sufficiently 

high levels. The substitute could cause 

symptoms of asphyxiation if air is 

displaced by vapors in a confined space. 

These potential health effects are 

common to many refrigerants. 

ASHRAE has adopted an OEL for the 

blend of 900 ppm (8-hr TWA).19 For the 

components of R–480A, the U.S. 

Occupational Safety and Health 

Administration (OSHA) has established 

a permissible exposure limit (PEL) of 

5,000 ppm (8-hr TWA) for CO2, AIHA 

has established a WEEL of 1,000 ppm 

for HFC–227ea, and ASHRAE has 

adopted an OEL of 800 ppm (8-hr TWA) 

for HFO–1234ze(E).20 EPA anticipates 

that users will be able to meet these 

workplace guidance limits and address 

potential health risks by following 

recommendations in the manufacturer’s 

SDS, ASHRAE Standard 15, other 

industry standards, and other safety 

precautions common to the refrigeration 

and air conditioning industry. 

Comparison to other substitutes in 

these end-uses: R–480A has an ODP of 

0, comparable to or less than other listed 

substitutes in these end-uses with ODPs 

ranging from 0 to less than 0.0004. 

For cold storage warehouses, R–480A 

with a GWP of 291 is lower than all 

other acceptable substitutes for retrofit 

equipment in this end-use, such as a 

number of HFC blends, including R– 

450A and R–513A, with GWPs of 601 

and 630, respectively. 

For commercial ice machines, R– 

480A’s GWP of 291 is lower than all 

other acceptable substitutes for retrofit 

equipment in this end-use, such as a 

number of HFC blends, including R– 

450A and R–513A, with GWPs of 601 

and 630, respectively. 

For positive displacement chillers, R– 

480A’s GWP of 291 is lower than that 

of certain other acceptable substitutes 

for retrofit equipment in this end-use, 

such as a number of HFC blends, 

including R–450A and R–513A, with 

GWPs of 601 and 630, respectively. The 

GWP of R–480A is higher than the 

GWPs of two other acceptable 

substitutes for retrofit equipment in this 

end-use, namely R–1224yd(Z) and R– 

514A, with GWPs of 1 21 and 2,22

respectively. EPA is listing this 

substitute as acceptable because 

available lower-GWP options are not 

feasible to use in certain applications. 

For example, equipment retrofitted with 

R–480A can operate within a specific 

temperature range and pressure range 

that other retrofitted chillers using 

lower-GWP options such as R– 

1224yd(Z) and R–514A cannot achieve. 

For refrigerated transport, R–480A’s 

GWP of 291 is lower than that of all 

other acceptable substitutes for retrofit 

equipment in this end-use, such as R– 

450A, R–513A, and HFC–134a, with 

GWPs of 601, 630, and 1,430, 

respectively. 

For water coolers, R–480A’s GWP of 

291 is lower than that of all other 

acceptable substitutes for retrofit 

equipment in this end-use, such as R– 

450A, R–513A, R–426A, and R–411A, 

with GWPs of 601, 630, 1,510, and 

1,600, respectively. 

Flammability and toxicity risks are 

comparable to or lower than 

flammability and toxicity risks of other 

available substitutes in the same retrofit 

end-uses. Toxicity risks can be 

minimized by use consistent with the 

OSHA PEL, AIHA WEEL, ASHRAE 

OELs, ASHRAE 15 and other industry 

standards, recommendations in the 

manufacturer’s SDS, and other safety 

precautions common in the refrigeration 

and air conditioning industry. 

Based on the considerations described 

above, EPA finds R–480A acceptable in 

retrofit equipment in the following enduses: cold storage warehouses, 

commercial ice machines, positive 

displacement chillers, refrigerated 

transport, and water coolers, because it 

does not pose greater overall 

environmental and human health risk 

than other available substitutes in the 

same end-uses. 

3. R–513A 

EPA’s decision: EPA finds R–513A 

acceptable as a substitute for use in: 

• Residential and light commercial 

air conditioning and heat pumps—selfcontained units (new equipment only). 

R–513A, marketed under the trade 

name Opteon® XP–10, is a weighted 

blend of 44 percent HFC–134a and 56 

percent HFO–1234yf by weight. HFC– 

134a is an HFC and is also known as 

1,1,1,2-tetrafluoroethane (CAS Reg. No. 

811–97–2). HFO–1234yf is an HFO and 

is also known as 2,3,3,3 tetrafluoroprop1-ene (CAS Reg. No.754–12–1). 

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 category in 

Docket EPA–HQ–OAR–2003–0118 at 

www.regulations.gov under the name, 

‘‘SNAP Information Notice for R–513A 

as a Refrigerant. SNAP Submission 

Received January 9, 2024.’’ EPA has 

performed an assessment to examine the 

health and environmental risks of this 

substitute and the results are 

summarized below. This assessment is 

available in Docket EPA–HQ–OAR– 

2003–0118: 

• ‘‘Risk Screen on Substitutes for Use 

in Residential and Light Commercial Air 

Conditioning and Heat Pumps—SelfContained Units (New Equipment) 

Substitute: R–513A (Opteon® XP–10).’’ 

Environmental information: R–513A 

is a blend of HFC–134a and HFO– 

1234yf with an ODP of 0. HFC–134a has 

a GWP of 1,430 23 and HFO–1234yf has 

a GWP of 1.24 The GWP of R–513A is 

630 when the two components are 

weighted by mass percentage of their 

GWPs. All components of the blends are 

excluded from the EPA’s regulatory 

definition of VOC under CAA 

regulations (see 40 CFR 51.100(s)) 

addressing the development of SIPs to 

attain and maintain the NAAQS. 

Knowingly venting or otherwise 

knowingly 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). 

Flammability information: The 

component HFO–1234yf has lower 

flammability as defined using the 


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25These are all examples of equipment defined as 

‘‘factory sealed appliances’’ in the UL 60335–2–40 

standard for electrical heat pumps, air-conditioners, 

and dehumidifiers, in which all refrigerating system 

parts have been sealed tight during the 

manufacturing process. Other equipment that meets 

the UL definition of factory sealed appliances are 

also self-contained units. 

standard test method ASTM E681. HFC– 

134a is not flammable using the same 

method. R–513A is not flammable as 

formulated in the WCF and the WCFF. 

ASHRAE has assigned R–513A a 

flammability class of ‘‘1,’’ meaning it 

does not propagate a flame under 

standard test conditions. 

Toxicity and exposure data: Potential 

health effects of exposure to this 

substitute include skin and eye 

irritation and frostbite upon contact. 

The substitute could cause asphyxiation 

if air is displaced by vapors in a 

confined space. These potential health 

effects are common to many refrigerants. 

EPA anticipates that R–513A will be 

used consistent with the 

recommendations specified in the SDS. 

ASHRAE has adopted an OEL for the 

blend R–513A of 650 ppm as an 8-hr 

TWA. The AIHA has established WEELs 

of 1000 ppm for HFC–134a and of 500 

ppm for HFO–1234yf, both as an 8-hr 

TWA. EPA anticipates that users will be 

able to meet these workplace guidance 

limits and will address potential health 

risks by following requirements and 

recommendations in the manufacturer’s 

SDSs, ASHRAE Standard 15, other 

industry standards, and other safety 

precautions common to the refrigeration 

and air conditioning industry. 

Comparison to other refrigerants in 

this end-use category: R–513A has an 

ODP of 0, which is comparable to other 

acceptable substitutes in the residential 

and light commercial air conditioning 

and heat pumps—self-contained units 

end-use category with ODPs ranging 

from 0 to less than 0.0004. R–513A 

which has a GWP of 630 is lower than 

or comparable to those of some 

acceptable substitutes in the same enduse category for which we are finding it 

acceptable, such as R–452B which has 

a GWP of 700 and HFC–32 which has 

a GWP of 675. R–513A has a GWP of 

630, which is higher than those of other 

acceptable substitutes in this end-use 

category such as R–290, which has a 

GWP of 3, R–454A, which has a GWP 

of 240, R–454B, which has a GWP of 

470, R–454C, which has a GWP of 150, 

and R–457A, which has a GWP of 140. 

While other acceptable substitutes 

have lower GWPs, EPA is listing R– 

513A as acceptable in this end-use 

category recognizing it likely will be 

used only in certain self-contained units 

that use R–134a where other available 

options are not technically feasible. 

Self-contained units can include but are 

not limited to window units, packaged 

terminal air conditioners, packaged 

terminal heat pumps, portable room air 

conditioning units, and portable air 

conditioners used to cool commercial 

aircraft interiors while on the ground.25

As a general matter, the replacements 

for most of the equipment in the 

residential and light commercial air 

conditioning and heat pumps end-use 

category use refrigerants that mimic the 

thermodynamic qualities and high 

pressure of R–410A which was the 

dominant refrigerant used for the 

majority of equipment types in this enduse category. There are, however, some 

specific applications where R–134a was 

used in self-contained units because of 

its unique thermodynamic properties 

that make it a better choice. For 

example, self-contained portable air 

conditioners used to cool commercial 

aircraft while on the ground currently 

use R–134a. This refrigerant is used 

because R–134a is optimized for 

equipment that use screw compressors 

and need to be able to operate at 

extremely high ambient temperatures 

with high humidity. R–513A’s 

thermodynamic properties closely 

mimic those of R–134a, making it an 

important option for applications where 

R–134a is used. As noted above, selfcontained portable air conditioners used 

to cool the aircraft interior while on the 

ground must function in a wide range of 

ambient temperatures and humidities, 

making R–513A an important option for 

this specific use. Other available 

refrigerant options with lower GWPs do 

not have the correct thermodynamic 

properties to fit the technical needs for 

this specific use. In addition, R–513A 

and R–134a are both low pressure 

refrigerants. As a result, R–513A could 

replace R–134a in equipment with 

minimal modifications but it is not 

expected to replace R–410A due to the 

extensive re-engineering required. 

EPA expects that use of R–513A in 

residential and light commercial air 

conditioning and heat pumps will be 

limited to a narrow set of specific 

applications because it is likely to be 

used only in those few applications 

where R–134a is currently used in selfcontained units and where other 

available options are not technically 

feasible. Therefore, EPA is listing this 

refrigerant as acceptable for use in the 

residential and light commercial air 

conditioning and heat pumps–selfcontained units end-use category. 

Flammability and toxicity risks are 

comparable to or lower than 

flammability and toxicity risks of other 

available substitutes in the same enduse category. For example, R–513A is 

non-flammable and has comparable or 

lower flammability risk compared to 

other acceptable refrigerants in this enduse category, such as the lower 

flammability refrigerants R–454B and 

R–454C. Toxicity risks can be 

minimized by use consistent with the 

AIHA’s WEELs, ASHRAE’s OEL, 

ASHRAE 15 and other industry 

standards, recommendations in the SDS, 

and other safety precautions common in 

the refrigeration and air conditioning 

industry. 

Based on the considerations described 

above, EPA finds R–513A acceptable in 

new self-contained units in the 

residential and light commercial air 

conditioning end-use because it 

provides a lower-GWP alternative for 

this end-use category. R–513A does not 

pose greater overall environmental and 

human health risk than other available 

substitutes in the same end-use 

category. 

B. Foam Blowing 

1. Extruded Polystyrene (XPS) Blowing 

Agent Blends of 0 to 90 Percent HFO– 

1336mzz(Z), 0 to 90 Percent HFO– 

1234ze(E), 0 to 75 Percent HFC–152a, 

and 0 to 90 Percent CO2

EPA’s decision: EPA finds blends of 0 

to 90 percent HFO–1336mzz(Z), 0 to 90 

percent HFO–1234ze(E), 0 to 75 percent 

HFC–152a, and 0 to 90 percent CO2

(‘‘HFO–1336mzz(Z)/HFO–1234ze(E)/ 

HFC–152a/CO2 blends’’) acceptable as a 

substitute for use as a foam blowing 

agent in: 

• Polystyrene: extruded boardstock 

and billet. 

HFO–1336mzz(Z) is an HFO and is 

also called (Z)-1,1,1,4,4,4-hexafluorobut2-ene or cis-1,1,1,4,4,4-hexafluorobut-2- 

ene (CAS Reg. No. 692–49–9); it also 

goes by the trade names of FEA–1100 or 

Formacel® 1100. HFO–1234ze(E) is an 

HFO and is also known as trans-1,3,3,3- 

tetrafluoroprop-1-ene (CAS Reg. No. 

29118–24–9). HFC–152a is an HFC and 

is also called ethane, 1,1-difluoro (CAS 

Reg. No. 75–37–6). CO2 has CAS Reg. 

No. 124–38–9. 

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 the docket 

(EPA–HQ–OAR–2003–0118) at https://

www.regulations.gov under the name, 

‘‘SNAP Information Notice for Extruded 

Polystyrene Blend of 0 to 90% HFO– 

1336mzz(Z), 0 to 90% HFO–1234ze(E), 

0 to 75% HFC–152a, and 0 to 90% CO2

as a Foam Blowing Agent SNAP 

Submission Received August 7, 2023.’’ 


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26WMO, 2022. 

27WMO, 2022. 

28Annex F to the Montreal Protocol. 

29Bellair 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. 30Cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO– 

1336mzz-Z) (2018). Toxicology and Industrial 

Health. 2019;35(3):180–188. doi:10.1177/ 

0748233719825530. 

31ASHRAE, 2022. 

32Annex F to the Montreal Protocol. 

33WMO, 2022. 

34 IPCC, 2007. 

35WMO, 2022. 

EPA has performed an assessment to 

examine the health and environmental 

risks of this substitute. This assessment 

is available in the docket EPA–HQ– 

OAR–2003–0118: 

• ‘‘Risk Screen on Substitutes for Use 

in Extruded Polystyrene Boardstock and 

Billet Foam Substitute: HFO– 

1336mzz(Z)/HFO–1234ze(E)/HFC–152a/ 

CO2 Blends.’’ 

Environmental information: These 

HFO–1336mzz(Z)/HFO–1234ze(E)/ 

HFC–152a/CO2 foam blowing agent 

blends have an ODP of 0. The 

components, HFO–1336mzz(Z), HFO– 

1234ze(E), HFC–152a, and CO2 have 

GWPs of 2,26 1,27 124,28 and 1, 

respectively. The GWPs of the blowing 

agent blends using these components 

range from 1 to 94. These reflect the 

composition ranges that result in the 

lowest GWP of 1 to the highest GWP of 

94 given the GWP and range of 

percentages for each component. The 

components of the HFO–1336mzz(Z)/ 

HFO–1234ze(E)/HFC–152a/CO2 blends 

are excluded from EPA’s regulatory 

definition of VOC under CAA 

regulations (see 40 CFR 51.100(s)) 

addressing the development of SIPs to 

attain and maintain the NAAQS. 

Flammability information: The 

component HFC–152a is flammable at 

standard temperature and pressure as 

defined by standard test method ASTM 

E681. HFO–1336mzz(Z) and HFO– 

1234ze(E) are not flammable at standard 

temperature and pressure using the 

same method. However, at higher 

temperatures, such as the temperatures 

typical for extruding XPS, HFO– 

1234ze(E) may also be flammable, 

particularly at higher humidity levels.29

HFO–1336mzz(Z)/HFO–1234ze(E)/ 

HFC–152a/CO2 blends anticipated to be 

used in manufacturing polystyrene: 

extruded boardstock and billet are 

flammable at the temperatures typical 

for extruding XPS. 

Toxicity and exposure data: Potential 

health effects of exposure to this 

substitute include skin or eye irritation 

or frostbite. At sufficiently high 

concentrations, the substitute may cause 

irregular heartbeat. The substitute could 

cause asphyxiation if air is displaced by 

vapors in a confined space. These 

potential health effects are common to 

many foam blowing agents. Exposure 

may be possible during the blowing of 

the foam if the foam manufacturer does 

not take standard precautions such as 

the use of personal protective 

equipment. EPA anticipates that these 

HFO–1336mzz(Z)/HFO–1234ze(E)/ 

HFC–152a/CO2 blends will be used 

consistent with the recommendations 

specified in the SDS. 

The AIHA has established a WEEL of 

1,000 ppm for HFC–152a as an 8-hr 

TWA. The WEEL committee of the 

OARS has established a WEEL of 500 

ppm 30 for HFO–1336mzz(Z). OSHA has 

established a PEL of 5,000 ppm on an 

8-hr TWA for CO2. The manufacturer of 

HFO–1234ze(E) recommends an OEL of 

800 ppm 31 (8-hr TWA) for this 

chemical. EPA anticipates that users 

will be able to meet the AIHA and 

OARS WEELs, OSHA PEL, and 

manufacturer’s OEL and will follow 

requirements and recommendations in 

the manufacturer’s SDSs and other 

safety precautions common to the foam 

blowing industry, thereby addressing 

potential health risks. 

Comparison to other foam blowing 

agents in this end-use: These HFO– 

1336mzz(Z)/HFO–1234ze(E)/HFC–152a/ 

CO2 blends have an ODP of 0, 

comparable to other acceptable 

substitutes in the polystyrene: extruded 

boardstock and billet end-use, such as 

HFC–152a, HFO–1234ze(E), methyl 

formate, and CO2. These HFO– 

1336mzz(Z)/HFO–1234ze(E)/HFC–152a/ 

CO2 blends’ GWPs from 1 to 94 are 

lower than or comparable to those of 

other acceptable substitutes in the same 

end-use for which we are finding it 

acceptable. Examples include HFC– 

152a, HFO–1234ze(E), light saturated 

hydrocarbons C3–C6, and methyl 

formate, with respective GWPs of 124,32

1,33 less than 4,34 and 11.35 Depending 

on the specific composition, the blend 

used may have a higher GWP than that 

of some individual chemicals that are 

acceptable substitutes in this end-use 

that are more flammable (e.g., HFO– 

1234ze(E)) or are less able to meet 

standard specifications (e.g., ASTM 

C578) than the blends because of 

properties such as solvency in the 

plastic resin (e.g., HFO–1336mzz(Z)) or 

contributions to insulation value (e.g., 

CO2, water). 

Flammability and toxicity risks are 

comparable to or lower than 

flammability and toxicity risks of other 

available substitutes in the same enduse. Toxicity risks can be minimized by 

use consistent with the AIHA’s and 

OARS’s WEELs, OSHA’s PEL, 

recommendations in the SDS, and other 

safety precautions common in the foam 

blowing industry. 

Based on the considerations described 

above, EPA finds blends of 0 to 90 

percent HFO–1336mzz(Z), 0 to 90 

percent HFO–1234ze(E), 0 to 75 percent 

HFC–152a, and 0 to 90 percent CO2

acceptable in the polystyrene: extruded 

boardstock and billet end-use because 

they do 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. 

Paul M. Gunning, 

Director, Office of Atmospheric Protection. 

Appendix A: Summary of Decisions for 

New Acceptable Substitutes 

REFRIGERATION AND AIR CONDITIONING

End-use Substitute Decision Further information 1

Cold storage warehouses 

(retrofit equipment only).

R–471A ................ Acceptable ............ This substitute is a blend of 78.7 percent hydrofluoroolefin (HFO)-1234ze(E), which is also 

known as trans-1,3,3,3-tetrafluoroprop-1-ene; (Chemical Abstracts Service Registry 

Number [CAS Reg. No.] 29118–24–9); 17.0 percent HFO–1336mzz(E), also known as 

trans-1,1,1,4,4,4-hexafluoro-2-butene (CAS Reg. No. 66711–86–2); and 4.3 percent 

HFC–227ea, which is also known as 1,1,1,2,3,3,3-heptafluoropropane (CAS Reg. No. 

431–89–0). 

R–471A has a global warming potential (GWP) of 144 and an ozone depletion potential 

(ODP) of 0. The blend is not flammable as it has an American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) flammability classification of ‘‘1’’. 


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REFRIGERATION AND AIR CONDITIONING—Continued 

End-use Substitute Decision Further information 1

ASHRAE has adopted an occupational exposure limit (OEL) for the blend of 710 ppm on 

an eight-hour time-weighted average (8-hr TWA). For the components of R–471A, the 

Workplace Environmental Exposure Limit (WEEL) Committee of the Occupational Alliance for Risk Science (OARS) has established a WEEL of 400 ppm on an 8-hr TWA for 

HFO–1336mzz(E), the AIHA has established a WEEL of 1,000 ppm for HFC–227ea (8- 

hr TWA), and ASHRAE has adopted an OEL of 800 ppm on an 8-hr TWA for HFO– 

1234ze(E). 

Cold storage warehouses 

(retrofit equipment only).

R–480A ................ Acceptable ............ This substitute is a weighted blend of 5 percent CO2, 86 percent HFO–1234ze(E), which is 

also known as trans-1,3,3,3-tetrafluoroprop-1-ene CAS Reg. No. 29118–24–9), and 9 

percent HFC–227ea, which is also known as 1,1,1,2,3,3,3-heptafluoropropane (CAS 

Reg. No. 431–89–0). 

R–480A has a GWP of 291 and an ODP of 0. The blend is not flammable as it has an 

ASHRAE flammability classification of ‘‘1.’’ 

ASHRAE has adopted an OEL for the blend of 900 ppm (8-hr TWA). For the components 

of R–480A, the Occupational Safety and Health Administration (OSHA) has established 

a permissible exposure limit (PEL) for CO2 of 5,000 ppm on an 8-hr TWA, AIHA has established a WEEL of 1,000 ppm for HFC–227ea (8-hr TWA), and ASHRAE has adopted 

an OEL of 800 ppm on an 8-hr TWA for HFO–1234ze(E). 

Commercial ice machines 

(retrofit equipment only).

R–480A ................ Acceptable ............ This substitute is a weighted blend of 5 percent CO2, 86 percent HFO–1234ze(E), which is 

also known as trans-1,3,3,3-tetrafluoroprop-1-ene CAS Reg. No. 29118–24–9), and 9 

percent HFC–227ea, which is also known as 1,1,1,2,3,3,3-heptafluoropropane (CAS 

Reg. No. 431–89–0). 

R–480A has a GWP of 291 and an ODP of 0. The blend is not flammable as it has an 

ASHRAE flammability classification of ‘‘1.’’ 

ASHRAE has adopted an OEL for the blend of 900 ppm (8-hr TWA). For the components 

of R–480A, OSHA has established a PEL for CO2 of 5,000 ppm on an 8-hr TWA, AIHA 

has established a WEEL of 1,000 ppm for HFC–227ea (8-hr TWA), and ASHRAE has 

adopted an OEL of 800 ppm on an 8-hr TWA for HFO–1234ze(E). 

Industrial process refrigeration (retrofit equipment 

only).

R–471A ................ Acceptable ............ This substitute is a blend of 78.7 percent HFO–1234ze(E), which is also known as trans1,3,3,3-tetrafluoroprop-1-ene; (CAS Reg. No. 29118–24–9); 17.0 percent HFO– 

1336mzz(E), also known as trans-1,1,1,4,4,4-hexafluoro-2-butene (CAS Reg. No. 

66711–86–2); and 4.3 percent HFC–227ea, which is also known as 1,1,1,2,3,3,3- 

heptafluoropropane (CAS Reg. No. 431–89–0). 

R–471A has a GWP of 144 and an ODP of 0. The blend is not flammable as it has an 

ASHRAE flammability classification of ‘‘1’’. 

ASHRAE has adopted an OEL for the blend of 710 ppm (8-hr TWA). For the components 

of R–471A, OARS has established a WEEL of 400 ppm on an 8-hr TWA for HFO– 

1336mzz(E), AIHA has established a WEEL of 1,000 ppm for HFC–227ea (8-hr TWA), 

and ASHRAE has adopted an OEL of 800 ppm on an 8-hr TWA for HFO–1234ze(E). 

Positive displacement chillers 

(retrofit equipment only).

R–480A ................ Acceptable ............ This substitute is a weighted blend of 5 percent CO2, 86 percent HFO–1234ze(E), which is 

also known as trans-1,3,3,3-tetrafluoroprop-1-ene CAS Reg. No. 29118–24–9), and 9 

percent HFC–227ea, which is also known as 1,1,1,2,3,3,3-heptafluoropropane (CAS 

Reg. No. 431–89–0). 

R–480A has a GWP of 291 and an ODP of 0. The blend is not flammable as it has an 

ASHRAE flammability classification of ‘‘1.’’ ASHRAE has adopted an OEL for the blend 

of 900 ppm (8-hr TWA). For the components of R–480A, the Occupational Safety and 

Health Administration (OSHA) has established a permissible exposure limit (PEL) for 

CO2 of 5,000 ppm on an 8-hr TWA, AIHA has established a WEEL of 1,000 ppm for 

HFC–227ea (8-hr TWA), and ASHRAE has adopted an OEL of 800 ppm on an 8-hr 

TWA for HFO–1234ze(E). 

Refrigerated transport (retrofit 

equipment only).

R–480A ................ Acceptable ............ This substitute is a weighted blend of 5 percent CO2, 86 percent HFO–1234ze(E), which is 

also known as trans-1,3,3,3-tetrafluoroprop-1-ene CAS Reg. No. 29118–24–9), and 9 

percent HFC–227ea, which is also known as 1,1,1,2,3,3,3-heptafluoropropane (CAS 

Reg. No. 431–89–0). 

R–480A has a GWP of 291 and an ODP of 0. The blend is not flammable as it has an 

ASHRAE flammability classification of ‘‘1.’’ ASHRAE has adopted an OEL for the blend 

of 900 ppm (8-hr TWA). For the components of R–480A, OSHA has established a PEL 

for CO2 of 5,000 ppm on an 8-hr TWA, AIHA has established a WEEL of 1,000 ppm for 

HFC–227ea (8-hr TWA), and ASHRAE has adopted an OEL of 800 ppm on an 8-hr 

TWA for HFO–1234ze(E). 

Residential and light commercial air conditioning and 

heat pumps—self-contained units (new equipment only).

R–513A ................ Acceptable ............ This HFC–134a/HFO–1234yf blend R–513A has an ODP of 0. Its components include 

HFC–134a which has a GWP of 1,430 and HFO–1234yf which has a GWP of 1. If these 

values are weighted by mass percentage, then the blend would have a GWP of 630. All 

components of the blends are excluded from EPA’s regulatory definition of VOC under 

CAA regulations (see 40 CFR 51.100(s)). 

ASHRAE has assigned R–513A a flammability class of ‘‘1,’’ meaning it does not propagate 

a flame under standard test conditions. ASHRAE has adopted an OEL for the blend R– 

513A of 650 ppm (8-hr TWA). The AIHA has established WEELs of 1000 ppm for HFC– 

134a and of 500 ppm for HFO–1234yf, both as an 8-hr TWA. 

Retail food refrigeration—Refrigerated food processing 

and dispensing equipment 

(retrofit equipment only).

R–471A ................ Acceptable ............ This substitute is a blend of 78.7 percent HFO–1234ze(E), which is also known as trans1,3,3,3-tetrafluoroprop-1-ene; (CAS Reg. No. 29118–24–9); 17.0 percent HFO– 

1336mzz(E), also known as trans-1,1,1,4,4,4-hexafluoro-2-butene (CAS Reg. No. 

66711–86–2); and 4.3 percent HFC–227ea, which is also known as 1,1,1,2,3,3,3- 

heptafluoropropane (CAS Reg. No. 431–89–0). 

R–471A has a GWP of 144 and an ODP of 0. The blend is not flammable as it has an 

ASHRAE flammability classification of ‘‘1’’. ASHRAE has established an OEL for the 

blend of 710 ppm on an eight-hour time-weighted average (8-hr TWA). For the components of R–471A, OARS has established a WEEL of 400 ppm on an 8-hr TWA for 

HFO–1336mzz(E), AIHA has established a WEEL of 1,000 ppm for HFC–227ea (8-hr 

TWA), and ASHRAE has adopted an OEL of 800 ppm on an 8-hr TWA for HFO– 

1234ze(E). 


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REFRIGERATION AND AIR CONDITIONING—Continued 

End-use Substitute Decision Further information 1

Retail food refrigeration—Remote condensing units (retrofit equipment only).R–471A ................ Acceptable ............ This substitute is a blend of 78.7 percent HFO–1234ze(E), which is also known as trans1,3,3,3-tetrafluoroprop-1-ene; (CAS Reg. No. 29118–24–9); 17.0 percent HFO– 

1336mzz(E), also known as trans-1,1,1,4,4,4-hexafluoro-2-butene (CAS Reg. No. 

66711–86–2); and 4.3 percent HFC–227ea, which is also known as 1,1,1,2,3,3,3- 

heptafluoropropane (CAS Reg. No. 431–89–0). 

R–471A has a GWP of 144 and an ODP of 0. The blend is not flammable as it has an 

ASHRAE flammability classification of ‘‘1’’. ASHRAE has established an OEL for the 

blend of 710 ppm (8-hr TWA). For the components of R–471A, OARS has established a 

WEEL of 400 ppm on an 8-hr TWA for HFO–1336mzz(E), AIHA has established a 

WEEL of 1,000 ppm for HFC–227ea (8-hr TWA), and ASHRAE has adopted an OEL of 

800 ppm on an 8-hr TWA for HFO–1234ze(E). 

Retail food refrigeration—Supermarket systems (retrofit 

equipment only).

R–471A ................ Acceptable ............ This substitute is a blend of 78.7 percent HFO–1234ze(E), which is also known as trans1,3,3,3-tetrafluoroprop-1-ene; (CAS Reg. No. 29118–24–9); 17.0 percent HFO– 

1336mzz(E), also known as trans-1,1,1,4,4,4-hexafluoro-2-butene (CAS Reg. No. 

66711–86–2); and 4.3 percent HFC–227ea, which is also known as 1,1,1,2,3,3,3- 

heptafluoropropane (CAS Reg. No. 431–89–0). 

R–471A has a GWP of 144 and an ODP of 0. The blend is not flammable as it has an 

ASHRAE flammability classification of ‘‘1’’. ASHRAE has established an OEL for the 

blend of 710 ppm (8-hr TWA). For the components of R–471A, OARS has established a 

WEEL of 400 ppm on an 8-hr TWA for HFO–1336mzz(E), AIHA has established a 

WEEL of 1,000 ppm for HFC–227ea (8-hr TWA), and ASHRAE has adopted an OEL of 

800 ppm on an 8-hr TWA for HFO–1234ze(E). 

Water coolers (retrofit equipment only).R–480A ................ Acceptable ............ This substitute is a weighted blend of 5 percent CO2, 86 percent HFO–1234ze(E), which is 

also known as trans-1,3,3,3-tetrafluoroprop-1-ene CAS Reg. No. 29118–24–9), and 9 

percent HFC–227ea, which is also known as 1,1,1,2,3,3,3-heptafluoropropane (CAS 

Reg. No. 431–89–0). 

R–480A has a GWP of 291 and an ODP of 0. The blend is not flammable as it has an 

ASHRAE flammability classification of ‘‘1.’’ ASHRAE has adopted an OEL for the blend 

of 900 ppm (8-hr TWA). For the components of R–480A, OSHA has established a PEL 

for CO2 of 5,000 ppm on an 8-hr TWA, AIHA has established a WEEL of 1,000 ppm for 

HFC–227ea (8-hr TWA), and ASHRAE has adopted an OEL of 800 ppm on an 8-hr 

TWA for HFO–1234ze(E). 

1See recommendations in the manufacturer’s SDS and guidance for all listed refrigerants. 

FOAM BLOWING

End-use Substitute Decision Further information 1

Polystyrene: Extruded 

boardstock and billet.

Extruded polystyrene (XPS) foam blowing 

agent blends of 0 to 90 percent HFO– 

1336mzz(Z), 0 to 90 percent HFO– 

1234ze(E), 0 to 75 percent HFC–152a, 

and 0 to 90 percent CO2.

Acceptable ............ HFO–1234ze(E) is also known as trans-1,3,3,3-tetrafluoroprop-1-ene 

(Chemical Abstracts Service Registry Number [CAS Reg. No.] 29118– 

24–9). HFO–1336mzz(Z) is also known as (Z)-1,1,1,4,4,4-hexafluoro2-butene and cis-1,1,1,4,4,4-hexafluoro-2-butene (CAS Reg. No. 692– 

49–9). HFC–152a is also known as 1,1-difluoroethane (CAS Reg. No. 

75–37–6). CO2 has CAS Reg. No. 124–38–9. 

These blends have 100-year GWPs from 1 to about 94, depending on 

the specific composition. Blends of these compounds anticipated to 

be used in manufacturing are flammable. 

The AIHA has established a WEEL of 1,000 ppm for HFC–152a on an 

eight-hour Time-Weighted Average (8-hr TWA). The OARS has established a WEEL of 500 ppm (8-hr TWA) for HFO–1336mzz(Z). The 

manufacturer of HFO–1234ze(E) has established an OEL of 800 ppm 

(8-hr TWA) and the American Society of Heating, Refrigerating and 

Air-Conditioning Engineers has adopted an OEL of 800 ppm (8-hr 

TWA) for this compound. The U.S. OSHA has established a PEL of 

5,000 ppm on an 8-hr TWA for CO2.

1See recommendations in the manufacturer’s SDS and guidance for all listed foam blowing agents. 

[FR Doc. 2024–28307 Filed 12–10–24; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Parts 261, 262, and 266 

[EPA–HQ–OLEM–2023–0081; FRL 8687–04– 

OLEM] 

RIN 2050–AH23 

Hazardous Waste Generator 

Improvements Rule, the Hazardous 

Waste Pharmaceuticals Rule, and the 

Definition of Solid Waste Rule; 

Technical Corrections 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Final rule. 

SUMMARY: The Environmental Protection 

Agency (EPA or the Agency) is 

finalizing five amendments that were 

withdrawn in its December 6, 2023, 

partial withdrawal of direct final rule. 

Due to receipt of adverse comments, the 

EPA withdrew eight amendments from 

the August 9, 2023, direct final rule that 

included revisions to the 2016 

Hazardous Waste Generator 

Improvements Rule, the 2019 Hazardous 

Waste Pharmaceuticals Rule and the 

2018 Vacatur of the Definition of Solid 

Waste Rule (88 FR 54086). The EPA is 


lotter on DSK11XQN23PROD with RULES1