Final—July 2, 2015

1

Significant New Alternatives Policy Program 

Refrigeration and Air Conditioning Sector

Risk Screen on Substitutes in Chillers and Industrial Process Air Conditioning

Substitute: R-513A (Opteon® XP10)

This risk screen does not contain Clean Air Act (CAA) Confidential Business Information 

(CBI) and, therefore, may be disclosed to the public.

1. INTRODUCTION

Ozone-depleting substances (ODS) are being phased out of production in response to a series of diplomatic 

and legislative efforts that have taken place over the past two decades, including the Montreal Protocol and 

the Clean Air Act Amendments of 1990 (CAAA). The U.S. Environmental Protection Agency (EPA), as 

authorized by Section 612 of the CAAA, administers the Significant New Alternatives Policy (SNAP) 

Program, which identifies acceptable and unacceptable substitutes for ODS in specific end-uses based on 

assessment of their health and environmental impacts. 

EPA’s decision on the acceptability of a substitute is based on the findings of a screening assessment of 

potential human health and environmental risks posed by the substitute in specific applications. EPA has 

already screened a large number of substitutes in many end-use applications within all of the major ODSusing sectors including: refrigeration and air conditioning, solvent cleaning, foam blowing, aerosols, fire 

suppression, adhesives, coatings and inks, and sterilization. The results of these risk screens are presented 

in a series of Background Documents that are available in EPA's docket.

The purpose of this risk screen is to supplement EPA’s Background Document on the refrigeration and air 

conditioning sector (EPA 1994) (hereinafter referred to as the Background Document). This risk screen 

evaluates the potential use of R-513A (also known as Opteon® XP10) as a substitute in the chillers enduse (specifically, centrifugal, reciprocating, screw, and scroll chillers) and the industrial process airconditioning end-use. Table 1 presents the composition of the proposed substitute. 

Table 1. Composition of R-513A and Potential Impurities

Constituent Chemical Formula CAS Number Concentration

(Weight Percent)

2,3,3,3-Tetrafluoropropene 

(HFO-1234yf) CH2CFCF3 754-12-1 ≤56%

1,1,1,2-Tetrafluoroethane

(HFC-134a) CF3CH2F 811-97-2 ≤44%

Potential Impurities

Section 2 summarizes the results of the risk screen for the proposed substitute blend listed in Table 1. The 

remainder of the risk screen is organized into the following sections:

• Section 3: Atmospheric Assessment

• Section 4: Volatile Organic Compound Assessment 

• Section 5: Potential Health Effects 

• Section 6: Flammability Assessment

• Section 7: Asphyxiation Assessment

• Section 8: Occupational Exposure Assessment 

• Section 9: General Population Exposure Assessment

• Section 10: References
Final—July 2, 2015

2

2. SUMMARY OF RESULTS

R-513A is recommended for SNAP approval for chillers and industrial process air conditioning. EPA's risk 

screen indicates that the use of the proposed substitute will be less harmful to the atmosphere than the 

continued use of ODS and other commonly used refrigerants, as it is less harmful to the ozone layer, has 

lower climate impact, and a shorter atmospheric lifetime. The components of R-513A are not subject to 

volatile organic compound (VOC) regulations under the CAA (40 CFR 51.100(s)), so environmental

impact from the release of these substances is not a concern. In addition, because R-513A is considered to 

be nonflammable, the proposed substitute is not expected to present a flammability concern. It is expected 

that the manufacturer’s safety data sheet (SDS) for R-513A and good manufacturing practices will be 

adhered to during handling or use of R-513A. 

Additionally, it is expected that the appropriate safety and personal protective equipment (PPE) (e.g., 

protective gloves, tightly sealed goggles, protective work clothing, and suitable respiratory protection in 

case of leakage or insufficient ventilation) consistent with Occupational Safety and Health Administration 

(OSHA) guidelines will be used during manufacture, installation and servicing, and disposal of industrial 

process air conditioning systems using R-513A. Because industrial process air conditioning systems are to 

be installed in locations with adequate space and/or ventilation in accordance with EPA recommendations 

and the equipment maintenance manuals for R-513A in this end-use, significant toxicity risk to consumers 

is also unlikely. Exposure at the end-use is captured in the occupational exposure assessment, as consumer 

use of industrial process air conditioning equipment is not anticipated. 

In addition, potential health risks from exposure to the proposed substitute is considered to be a larger 

concern for workers than asphyxiation,1 due to the large spaces in which these systems are installed and 

serviced. Additional safeguards, including specified refrigerant concentration limits (RCL) of R-513A

components, are also provided by adherence to industry standards including American Society of Heating, 

Refrigerating and Air-Conditioning Engineers (ASHRAE) Standards 15,2 34,3 and 62.4

3. ATMOSPHERIC ASSESSMENT

This section presents an assessment of the potential risks to atmospheric integrity posed by the use of R513A in chillers and industrial process air conditioning. The ozone depletion potential (ODP), global 

warming potential (GWP), and atmospheric lifetime (ALT) of the proposed substitute are presented in 

Table 2.

The proposed substitute is substantially less harmful to the ozone layer, has lower climate impact, and a 

shorter ALT when compared to refrigerants such as CFC-12 and HCFC-22. In addition, R-513A has lower 

climate impact and a shorter ALT than those predicted for other substitutes examined in the Background 

Document as well as commonly utilized refrigerants HFC-134a, R-404A, and R-507A. Thus, EPA 

believes that the use of R-513A would result in substantially less harm to the climate and ozone layer than 

the continued use of ODS and other commonly used refrigerants in chillers and industrial process air 

conditioning systems. 

 1 The oxygen deprivation limit (ODL) for R-513A is 100,000 ppm per Standard 34-2010 (ASHRAE 2015). Exposure estimates 

remain significantly below this level (see Table 6). 

2 Safety Standard for Refrigeration Systems ASHRAE Standard 15 establishes safeguards for life, limb, health, and property and 

prescribes safety requirements.

3 Designation and Safety Classification of Refrigerants ASHRAE Standard 34 establishes a uniform system for assigning reference

numbers, safety classifications, and refrigerant concentration limits to refrigerants. Safety classifications based on toxicity and 

flammability data are included.

4 Ventilation for Acceptable Indoor Air Quality ASHRAE Standard 62 establishes minimum ventilation rates and other measures 

intended to provide indoor air quality that is acceptable to human occupants and that minimizes adverse health effects.
Final—July 2, 2015

3

Table 2. Atmospheric Impacts of R-513A Components Compared to Other Refrigerants

Refrigerant Ozone Depleting Potential

(ODP)a

Global Warming Potential

(GWP)b

Atmospheric Lifetime in 

Years (ALT)b

R-513A 0 631 NAc

Individual Components

HFC-134a 0 1,430 14

HFO-1234yf 0 4d 11 daysd

CFC-11 1.0 4,750 45

CFC-12 0.82 10,900 100

R-500e 0.7 8,077 NAf

HCFC-22 0.13 1,810 12

HCFC-123 0.01 77 1.3

HFC-134a 0 1,430 14

HFC-236fa 0 9,810 240

R-407Cg 0 1,774 NAh

a WMO 2010 Scientific Assessment Report (2011)

b IPCC 4th Assessment Report (Forster et al. 2007) c Atmospheric lifetimes are not given for blends, because the components separate in the atmosphere. The ALT for the individual components 

are also listed in Table 2. d Papadimitriou et al. (2007)

e R-500 is a blend consisting of CFC-12 (73.8%) and HFC-152a (26.2%). f Atmospheric lifetimes are not given for blends, because the components separate in the atmosphere. The ALT for CFC-12 is 100 years and 

HFC-152a is 1.4 years (IPCC 4th Assessment Report [Forster et al. 2007]).

g R-407C is a blend consisting of HFC-32 (29%), HFC-125 (25%) and HFC-134a (52%). h Atmospheric lifetimes are not given for blends, because the components separate in the atmosphere. The ALT for HFC-32 is 4.9 years, the 

ALT for HFC-125 is 29 years, and the ALT for HFC-134a is 14 years (IPCC 4th Assessment Report [Forster et al. 2007]).

4. VOLATILE ORGANIC COMPOUND ASSESSMENT

The components of R-513A, HFC-134a and HFO-1234yf, are exempt from the definition of VOCs under 

CAA regulations (40 CFR 51.100(s)). Therefore, VOC impacts from the release of R-513A are not a 

concern. 

5. POTENTIAL HEALTH EFFECTS

To assess potential health risks from exposure to the proposed substitute in chillers and industrial process 

air conditioning, EPA identified the relevant toxicity threshold values for comparison to modeled exposure 

concentrations for different scenarios. According to ASHRAE Standard 34-2013, R-513A is listed under 

safety group A1 with a RCL of 72,000 ppm (ASHRAE 2015). ASHRAE 34 RCLs are intended to reduce 

the risks of acute toxicity, asphyxiation, and flammability hazards in normally occupied, enclosed spaces 

during refrigerant use and protect end-users from the potential dangers of a catastrophic leak from a 

refrigeration unit (ASHRAE 2010b). ASHRAE Standard 15 implements the aforementioned standard, 

requiring that “the concentration of refrigerant in an enclosed space following a complete discharge of a 

high-probability system shall not exceed the RCL” (ASHRAE 2010a). As such, this risk screen references 

the proposed RCL for R-513A in addition to the hypoxia no observed adverse effect level (NOAEL), and 

exposure limits, as an additional, conservative limit to ensure that significant asphyxiation and toxicity

risks, respectively, do not occur. 

For the occupational exposure analysis, potential risks from chronic and acute worker exposure were

evaluated by comparing exposure concentrations to available occupational exposure limits. Potential risks 

of chronic worker exposure were evaluated using workplace guidance levels (WGL), such as Workplace 

Environmental Exposure Levels (WEELs). Risks from potential short-term consumer exposures were 

evaluated by comparing exposure concentrations to emergency guidance levels (EGL). In the absence of 

an established short-term exposure limit (STEL), acute exposure guideline level (AEGL), or emergency 
Final—July 2, 2015

4

response planning guideline (ERPG) for R-513A, potential short-term end-use exposures were evaluated 

on a component basis (i.e., HFC-134a and HFO-1234yf). Table 3 lists the relevant toxicity limits for R513A and its components, and is followed by Table 4, which provides an explanation of each toxicity 

limit. EPA’s approach for identifying or developing these values is discussed in Chapter 3 of the 

Background Document. 

Table 3. Exposure Limits of R-513A Components

R-513A

Component

WGL

(Long-term Exposure)

ppm

EGL 

(Short-term Exposure)

ppm

Refrigerant Concentration 

Limit (RCL)

ppm

R-513A 653 (8-hour AEL) 1,960 (15-min STEL)a 72,000

Individual Components

HFC-134a 1,000 (8-hour WEEL) 8,000 (10-min AEGL-1)

8,000 (30-min AEGL-1) 50,000

HFO-1234yf 500 (8-hour WEEL) 1,500 (15-min STEL)b 101,000c

a Neither the American Conference of Governmental Industrial Hygienists (ACGIH) nor the American Industrial Hygiene Association (AIHA)

recommend ceiling or short term exposure limits for the R-513A blend. A STEL for R-513A of 1,960 ppm was developed by EPA based on the 

653 ppm acceptable exposure limit (AEL) value. The STEL was estimated as three to five times the AEL, which is an established method of 

estimating a short-term exposure limit by ACGIH. [STEL] = [AEL] x 3 = 653 ppm x 3 ≈ 1,960 ppm b Neither ACGIH nor AIHA recommend ceiling or short term exposure limits for HFO-1234yf. A STEL for HFO-1234yf of 1,500 ppm was 

developed by EPA based on the 500 ppm WEEL value. The STEL was estimated as three to five times the AEL, which is an established method 

of estimating a short-term exposure limit by ACGIH. [STEL] = [AEL] x 3 = 500 ppm x 3 ≈ 1,500 ppm c Although an RCL has not been proposed for HFO-1234yf, the recommended acute toxicity exposure limit (ATEL) for HFO-1234yf is 101,000 

ppm (DuPont Fluoroproducts 2014).

Table 4. Explanation of Exposure Limit-Related Terminologya

Organization Definition

OSHA Occupational Safety and Health Administration

NIOSH National Institute for Occupational Safety and Health

ACGIH American Conference of Governmental Industrial Hygienists

AIHA American Industrial Hygiene Association

OARS Occupational Alliance for Risk Science

Exposure Limit Definition Explanation

Short-Term Exposure

RCL Refrigerant Concentration 

Limit

The RCL for a refrigerant is intended to reduce the risks of acute toxicity, 

asphyxiation, and flammability hazards in normally occupied, enclosed 

spaces. The RCL for each refrigerant is the lowest of the Acute-Toxicity 

Exposure Limit (ATEL), Oxygen Deprivation Limit (ODL), and Flammable 

Concentration Limit (FCL). Determination assumes full vaporization with 

no removal by ventilation, dissolution, reaction, or decomposition and 

complete mixing of refrigerant in the space to which it is released.

ATEL Acute Toxicity Exposure Limit The ATEL is the refrigerant concentration limit intended to reduce the 

risks of acute toxicity hazards in normally occupied, enclosed spaces 

according to ASHRAE Standard 34. The ATEL includes consideration of 

mortality, cardiac sensitization, anesthetic or central nervous system 

effects and other escape impairing effects and permanent injury. The 

ATEL is similar to the Immediately Dangerous to Life or Health (IDLH)

concentrations set by NIOSH.

STEL Short-Term Exposure Limit A 15-minute time-weighted average (TWA) exposure that should not be 

exceeded during a workday, even if the 8-hour TWA is within the 

threshold limit value-time weighted average threshold limit value-timeweighted average (TLV–TWA), set by ACGIH. 
Final—July 2, 2015

5

AEGLb,c

Acute Exposure Guideline 

Level 1

AEGL-1 is the airborne concentration (expressed as ppm or mg/m3) of a 

substance above which it is predicted that the general population, 

including susceptible individuals, could experience notable discomfort, 

irritation, or certain asymptomatic nonsensory effects. However, the 

effects are not disabling and are transient and reversible upon cessation 

of exposure. 

Acute Exposure Guideline 

Level 2

AEGL-2 is the airborne concentration (expressed as ppm or mg/m3) of a 

substance above which it is predicted that the general population, 

including susceptible individuals, could experience irreversible or other 

serious, long-lasting adverse health effects or an impaired ability to 

escape.

Acute Exposure Guideline 

Level 3

AEGL-3 is the airborne concentration (expressed as ppm or mg/m3) of a 

substance above which it is predicted that the general population, 

including susceptible individuals, could experience life-threatening health 

effects or death.

Long-Term Exposure

PEL Permissible Exposure Limit This is an 8-hour TWA exposure limit set by OSHA. 

AEL Acceptable Exposure Limit The maximum 8-hour TWA at which a worker can be exposed regularly 

without adverse effects.

WEEL Workplace Environmental 

Exposure Level 

Developed by OARS for to protect healthy workers against acute and 

chronic health effects, this limit is based on repeated daily exposures 

over a working lifetime and averaged over an 8-hour workday. 

TLV-TWA Threshold Limit Value –TimeWeighted AverageThe TWA concentration for a conventional 8-hour workday and a 40-

hour workweek, to which it is believed that nearly all workers may be 

repeatedly exposed, day after day, for a working lifetime without adverse 

effect according to ACGIH. 

a All information in this table taken from EPA (1994) except where otherwise noted.

b EPA (2012)

c Applicable to emergency exposure periods ranging from 10 minutes to 8 hours.

According to the SDS, exposure to R-513A may be hazardous if inhalation, skin contact, or eye contact 

with the substitute occurs. The most likely pathway of exposure is through inhalation. R-513A can cause 

symptoms of asphyxiation when present in concentrations high enough to significantly lower oxygen 

concentrations below 19.5 percent by volume, such as headaches, ringing in ears, dizziness, drowsiness, 

nausea, vomiting, depression of all senses, and also unconsciousness. Under some circumstances of overexposure (i.e., oxygen levels fall below 6 percent by volume), death may occur.

If inhaled, R-513A can cause symptoms such as light-headedness, dizziness, confusion, incoordination, 

drowsiness, unconsciousness, and anesthetic effects. Excessive inhalation of R-513A may also result in an 

irregular heartbeat or death, due to cardiac effects. Furthermore, R-513A vapors are denser than air and can 

cause asphyxiation if the oxygen concentration in a room is significantly reduced. 

If R-513A is inhaled, person(s) should be immediately removed from the contaminated space and exposed 

to fresh air. In accordance with the SDS, EPA further recommends that if breathing is difficult or irregular, 

person(s) should be given oxygen, provided a qualified operator is present, and medical attention be 

sought. Exposures of R-513A to the skin may cause frostbite. In the case of dermal exposure, the SDS for 

R-513A recommends that person(s) immediately wash the affected area with water and remove all 

contaminated clothing; if frostbite occurs, bathe (not rub) the affected area with lukewarm, not hot, water. 

If water is not available, cover the affected area with a clean, soft cloth, and seek medical attention 

immediately. Exposures of R-513A to the eyes could cause eye irritation. In case of ocular exposure, the 

SDS for R-513A recommends that person(s) immediately flush the eyes, including under the eyelids, with 

copious amounts of water for 15 minutes. 

EPA’s review of the human health impacts of this proposed substitute is contained in the public docket for 

this decision. These risks and procedures after exposure are similar for other common refrigerants. The 
Final—July 2, 2015

6

potential health effects of R-513A can be minimized by following the exposure guidelines, and ventilation 

and PPE recommendations outlined in the SDS for R-513A and this risk screen.

6. FLAMMABILITY ASSESSMENT

R-513A is classified as an A1 refrigerant by ASHRAE, and is considered to be nonflammable (DuPont 

Fluoroproducts 2014; ASHRAE 2015). Based on this classification, manufacture, servicing, and use of R513A is not expected to present a flammability risk in chillers or industrial process air conditioning.

7. ASPHYXIATION ASSESSMENT

R-513A is not expected to cause a significant risk of asphyxiation when used in chillers or industrial 

process air conditioning. These systems are typically installed in large spaces (e.g., outdoors, on roofs, 

large manufacturing facilities) where it would be unlikely for a release of R-513A to reduce the normal 

concentration of oxygen in air (21 percent) in the space to 12 percent,5 even in the case of a catastrophic 

leak. EPA believes that by installing R-513A chillers and industrial process air conditioning systems in 

appropriate spaces according to guidelines from the manufacturer and the SDS for R-513A, potential 

releases of R-513A are not expected to pose a significant risk of asphyxiation or impaired coordination to 

personnel, and are consistent with the potential risks for other commonly used refrigerants in these enduses. 

8. OCCUPATIONAL EXPOSURE ASSESSMENT

This section assesses potential exposures to workers during manufacture, installation, servicing, and 

disposal of R-513A chillers and industrial process air conditioning systems. To ensure that use of the 

proposed substitute in chillers and industrial process air conditioning does not pose an unacceptable risk to 

workers during installation, servicing, and disposal, occupational exposure modeling at installation was 

performed for the proposed substitute. All installation, maintenance, and disposal activities for R-513A

chillers and industrial process air conditioning systems are anticipated to occur on-site. Although modeling 

is only performed for installation, it is assumed that exposure during servicing and disposal would not 

exceed exposure during installation because similar refrigerant charging and/or recovery equipment would 

be used. Furthermore, because it is likely that an equivalent or marginally less refrigerant amount remains 

in the unit at disposal as would be present during installation or servicing, it is assumed that installation of

refrigeration units in chillers and industrial process air conditioning systems would require transfer of a 

greater amount of refrigerant, and thus result in greater worker exposure. Thus, occupational exposure was 

conservatively modeled based on installation.

According to the submitter, charge sizes in positive displacement and centrifugal chillers can range from 

typical charge sizes of 300 kg and 500 kg, respectively, and maximum charge sizes of 600 kg and 10,000 

kg, respectively. Industrial process air conditioning systems can range from a typical charge size of 30 kg 

to a maximum charge size of 5,000 kg. The anticipated maximum and typical charge sizes for the proposed 

applications are summarized in Table 5. 

Table 5. Typical and Maximum Charge Sizes for R-513A Chillers and Industrial Process Air 

Conditioning Applications

End-Use Application Typical Charge Size 

(kg)

Maximum Charge 

Size (kg)

Chillers Positive Displacement 300 600

Centrifugal 500 10,000

Industrial Process Air Conditioning Industrial Process Air Conditioning 30 5,000

 5 Twelve percent oxygen in air is the No Observed Adverse Effect Level (NOAEL) for hypoxia (ICF 1997).
Final—July 2, 2015

7

Installation of chillers and industrial process air conditioning systems is expected to occur with limited 

frequency (up to approximately one event per day) and with limited duration of exposure to the refrigerant 

charge. Release points during charging would be connection/disconnection of temporary lines from 

charging equipment. Refrigerant contained in temporary lines during charging would be recovered, and 

breaking of fittings should result in de minimus releases. Such activities and related exposure is anticipated 

to occur within 15-30 minutes (per event/day). To evaluate the risk of exposure at installation, the 

maximum modeled exposure concentration for each component of R-513A was compared to the 15-minute

STEL values, which were developed by EPA for each component based on the individual WEEL values.

The methodology used for this screening assessment is described in Chapter 5 of the Background 

Document. A box-model approach was used to evaluate potential worker exposure to alternative 

refrigerants. This approach has been widely used for many years to estimate probable exposures of 

workers to hazardous airborne materials, and has been described in detail by NIOSH. This model takes 

into consideration the duration and magnitude of the resulting exposure which is influenced by 1) duration 

and intensity of the release, 2) rate at which contaminated air is diluted with uncontaminated air, 3) 

proximity of the worker to the source of the release, and 4) the length of time the worker remains in the 

affected space.

The release per event was assumed to be 0.2 percent and 1 percent of the equipment charge during 

installation6 for chillers and industrial process air conditioning systems, respectively, and was multiplied 

by the number of installations estimated to occur over a workday (i.e., one installation was assumed for 

both chillers and industrial process air conditioning systems). The analysis models both the typical and 

maximum anticipated charge sizes for chillers and industrial process air conditioning systems, due to the 

wide range in charge sizes provided by the submitter. The maximum 15-minute TWA exposures for each 

R-513A constituent were estimated for the installation exposure scenario and compared to their respective 

STELs and RCLs (see Table 6). Because HFO-1234yf is present in larger concentrations and because it 

has a lower exposure limit than HFC-134a, Table 6 only presents exposures for HFO-1234yf, the 

component with greater potential concerns.

Table 6. Occupational Risk Assessment at Installation for R-513Aa

 6 IPCC (2006) estimates that first-fill losses during installation of industrial process air conditioning systems can range from 0.5% 

to 3%; DECC (2011) estimates that first-fill losses for industrial process air conditioning is approximately 1%; and SKM Enviros 

(2011) suggests that this loss rate should be less than 4%. A proposed update to EPA’s Vintaging Model recommends a first-fill 

emissions rate of 1% from industrial process air conditioning manufactured after 1990.
Final—July 2, 2015

8

System Charge 

Size (kg)

R-513A 

Component

Release 

Rateb

15-minute TWA 

Occupational 

Exposure 

(ppm)

15-min 

Short Term 

Exposure 

Limit

(ppm)c

Refrigerant 

Concentration 

Limit (RCL) 

(ppm)

Chillers 300

HFO-1234yf

0.2% 40

1,500 101,000d 10,000 1,330

Industrial Process Air 

Conditioning

30 1% 20

5,000 3,330

Bold font indicates modeling results. a Cells highlighted in green are the scenarios that are deemed to be acceptable given various modeling assumption options.

b Release rates are consistent with IPCC (2006), CARB (2013), and EPA’s Vintaging Model. c EPA-derived STEL; see Table 3 for more information. d ATEL for HFO-1234yf is 101,000 ppm; see Table 3 for more information.

Based on the assumptions described above, the short-term (15-minute) worker exposure concentrations are 

not likely to exceed the STEL for the HFO-1234yf component of R-513A for the typical and maximum

charge sizes for chillers or for the typical charge size for industrial process air conditioning. The modeling 

indicates that worker exposure could exceed the STEL for the HFO-1234yf component for the installation 

scenario for the maximum charge size for industrial process air conditioning; however, the estimated 

exposures were derived using conservative assumptions, and do not take into account the use of ventilation 

or PPE. In addition, all of the estimated exposures for each component are significantly lower than their 

respective RCLs and ATELs, which are limits intended to reduce the risks of acute toxicity hazards in 

normally occupied, enclosed spaces according to ASHRAE Standard 34. 

The maximum charge sizes for chillers and industrial process air conditioning systems are representative 

of large systems, and as such, additional precautions are appropriate for such applications. Furthermore, 

the modeling assumptions do not reflect the use of any local exhaust ventilation or other engineering 

controls, which are likely to be used during installation, servicing, and disposal operations, thereby 

preventing significant exposure to R-513A. Chillers and industrial process air conditioning systems are 

complex systems used in various types of commercial and manufacturing industries and are installed in 

large facilities. Such facilities are already equipped with proper engineering controls and industrial hygiene 

practices for safety purposes and therefore are expected to have the capabilities to mitigate exposures to 

any large releases of refrigerant from the refrigeration system. Facility personnel are also equipped with 

proper PPE and trained to work in such environments that contain numerous workplace hazards, and are 

expected to be only at marginally incremental risk for exposures to refrigerant releases in these settings.

Furthermore, these types of systems are typically installed, maintained, and disposed of by trained and 

EPA Section 608-certified refrigerant technicians using proper industrial hygiene techniques. When 

installing, servicing, or disposing of such large refrigeration systems, these techniques should be strictly 

followed. Adherence to the proposed substitute’s SDS and use of proper engineering controls and PPE 

make it unlikely that exposure to R-513A would occur. Adequate ventilation should always be established 

during any use, handling, or storage of R-513A. If installation, recovery, and/or disposal is taking place in 

an enclosed space without any mechanical ventilation, facilities should be cleared of non-essential 

personnel and technicians should wear a self-contained breathing apparatus (SCBA) and other appropriate 

protective equipment. Engineering controls should include vapor-in air detection systems and local exhaust 

ventilation during use of R-513A to prevent dispersion throughout the workplace. In addition, an eye wash 

and safety shower should be near the manufacturing facility and locations where R-513A is stored and 

ready for use. In general, use of PPE is recommended, such as splash goggles, mechanically-resistance 

gloves when handling cylinders, and chemically-resistant gloves when handling the gas mixture (e.g., 

butyl rubber, chlorinated polyethylene, or neoprene).

Toxicity risks would be further minimized by the installation of signage which warns room occupants to 

remain standing (as higher concentrations are likely to accumulate near the floor), not enter recessed parts 
Final—July 2, 2015

9

of the facility (e.g., maintenance crawl spaces and below grade service areas), and exit the facility 

immediately should they hear the refrigerant detector alarm and/or smell the leaked refrigerant.

In addition, as for other halogenated refrigerants, there is a risk of generation of toxic degradation products 

such as hydrogen fluoride and hydrogen chloride if the components of R-513A (i.e., HFC-134a and HFO1234yf) are exposed to high temperatures or fire. Other reaction products such as carbon dioxide might 

also be present. Containers should be stored in cool, dry conditions (maximum storage temperature should 

be 40°C) in well-sealed receptacles and should not be allowed to contact open flames, glowing metal 

surfaces, or electrical heating elements. EPA believes that when proper handling and disposal guidelines 

are followed, in accordance with both good industrial hygiene practices and the SDS for R-513A and its 

components, there is no significant risk to workers during the use of R-513A as a refrigerant in chillers and 

industrial process air conditioning systems.

9. GENERAL POPULATION EXPOSURE ASSESSMENT

R-513A is not expected to cause a significant risk to human health in the general population when 

manufactured for use and used as a refrigerant in chillers and industrial process air conditioning systems. 

The proposed substitute will be manufactured in a closed process and is proposed for use in closed 

systems; thus, significant releases are not anticipated. At room temperature, R-513A is a gas and, 

therefore, releases to ground or surface water are not anticipated, as R-513A is anticipated to dissipate into 

the atmosphere upon release to outside air (i.e., because natural ventilation rates would be higher and there 

is no enclosed space to maintain a high concentration of R-513A). Should air releases during 

manufacturing operations occur, engineering controls should be used (e.g., carbon absorption scrubbers) to 

collect R-513A and prevent the release of R-513A to the atmosphere. EPA believes that by using proper 

engineering controls and by following disposal and containment recommendations outlined in the 

proposed substitute’s SDS and this risk screen, exposure to R-513A is not expected to pose a significant 

toxicity risk to the general population. 
Final—July 2, 2015

10

10. REFERENCES

ACGIH. 2012. Guide to Occupational Exposure Values. American Conference of Governmental 

Industrial Hygienists.

AIHA. 2013. WEEL® Values (2011). 2013 ERPG/WEEL Handbook. AIHA Guideline Foundation. 

Available online at: https://www.aiha.org/getinvolved/AIHAGuidelineFoundation/WEELs/Pages/default.aspx.

ANSI/ASHRAE. 2015. 2015 Supplement to Standard 34: Designation and Safety Classification of 

Refrigerants. American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.

ANSI/ASHRAE. 2013. Standard 62: Ventilation for Acceptable Indoor Air Quality. American Society of 

Heating, Refrigerating and Air-Conditioning Engineers, Inc.

ANSI/ASHRAE. 2010a. Standard 15: Safety Standard for Refrigeration Systems. American Society of 

Heating, Refrigerating and Air-Conditioning Engineers, Inc.

ANSI/ASHRAE. 2010b. Standard 34: Designation and Safety Classification of Refrigerants. American 

Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. 

DuPont Fluoroproducts. 2014. Opteon® XP40 for Use as a Refrigerant. Significant New Alternatives 

Policy Program Submission to the United States Environmental Protection Agency. August 2014.

Forster, P., V. Ramaswamy, P. Artaxo, T. Berntsen, R. Betts, D.W. Fahey, J. Haywood, J. Lean, D.C. 

Lowe, G. Myhre, J. Nganga, R. Prinn, G. Raga, M. Schulz and R. Van Dorland. 2007. Changes in 

Atmospheric Constituents and in Radiative Forcing. In: 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., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M.Tignor and 

H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

ICF. 1997. Physiological Effects of Alternative Fire Protection Agents - Hypoxic Atmospheres 

Conference. Stephanie Skaggs prepared the proceedings of the conference held May 22, 1997 in New 

London, CT.

IPCC. 2013. Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the 

Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin, G.-K. 

Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. 

Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 1535 pp.

IPCC. 2006. IPCC Guidelines for National Greenhouse Gas Inventories. Volume 3: Industrial Processes 

and Product Use, Chapter 7: Emissions of Fluorinated Substitutes for Ozone Depleting Substances.” 

November 2008. Available at: http://www.ipccnggip.iges.or.jp/public/2006gl/pdf/3_Volume3/V3_7_Ch7_ODS_Substitutes.pdf. 

Mackenzie, F.T. and J.A. Mackenzie. 1995. Our changing planet. Prentice-Hall.

OSHA. 2004. “Safety and Health Topics: Isobutane.” February 2004. Available online at: 

<http://www.osha.gov/dts/chemicalsampling/data/CH_247840.html>.

UL. 2010. UL 471: Commercial Refrigerators and Freezers. Underwriters Laboratory.
Final—July 2, 2015

11

Papadimitriou, V., R.K. Talukdar, R.W. Portmann, A.R. Ravishankara, and J.B. Burkholder. 2007. 

CF3CF=CH2 and (Z)-CF3CF=CHF: Temperature dependent OH rate coefficients and global warming 

potentials. Physical Chemistry Chemical Physics. 9: 1-13.

UK Department of Energy & Climate Change (DECC). 2011. “Development of the GHG Refrigeration 

and Air Conditioning Model.” Prepared by ICF International. November 2011. Available at 

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/48250/3844-greenhousegas-inventory-improvement-project-deve.PDF.

U.S. EPA. 2012. Acute Exposure Guidelines (AEGLs) Definitions. Available online at: 

http://www.epa.gov/oppt/aegl/pubs/define.htm.

U.S. EPA. 1994. Significant New Alternatives Policy Technical Background Document: Risk Screen on 

the Use of Substitutes for Class I Ozone-depleting Substances: Refrigeration and Air Conditioning. 

Stratospheric Protection Division. March 1994.

WMO (World Meteorological Organization). 2011. Scientific Assessment of Ozone Depletion: 2010, 

Global Ozone Research and Monitoring Project-Report No. 52, 516 pp., Geneva, Switzerland.