### FINAL July 2, 2015 1 

## Significant New Alternatives Policy Program Refrigeration and Air Conditioning Sector
Risk Screen on Substitutes in Refrigerated Transpor t

Substitute: R-449A (Opteon® XP40)

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

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



### 1. INTRODUCTION
Ozone-depleting substances (ODS) are being phased o ut of production in response to a series of diploma tic and legislative efforts that have taken place over the past two decades, including the Montreal Protoc ol 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 unacceptab le substitutes for ODS in specific end-uses based o n assessment of their health and environmental impact s. 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 pose d by the substitute in specific applications. EPA has already screened a large number of substitutes in m any end-use applications within all of the major OD Susing sectors including: refrigeration and air cond itioning, solvent cleaning, foam blowing, aerosols, fire suppression, adhesives, coatings and inks, and ster ilization. The results of these risk screens are pr esented in a series of Background Documents that are availa ble in EPA's docket.
The purpose of this risk screen is to supplement EP A’s Background Document on the refrigeration and ai r conditioning sector (EPA 1994) (hereinafter referre d to as the Background Document). This risk screen evaluates the potential use of R-449A (also known a s Opteon® XP40) as a substitute in the refrigerated transport end-use, specifically in trucks and trail ers. Table 1 presents the composition of the propos ed substitute.
Table 1. Composition of R-449A and Potential Impur ities

Constituent Chemical Formula CAS Number Concentration (Weight Percent) Difluoromethane (HFC

- 32) CH 2 F 2 75

- 10

- 5 ≤24.3% 1,1,1,2,2

- Pentafluoroethane (HFC

- 125) CF 3 CHF 2 354

- 33

- 6 ≤24.7% 2,3,3,3

- Tetrafluoropropene (HFO

- 1234yf) CH 2 CFCF 3 754

- 12

- 1 ≤25.3% 1,1,1,2

- Tetrafluoroethane (HFC

- 134a) CF 3 CH 2 F 811

- 97

- 2 ≤25.7% 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: Discussion of End-Use Scenarios Modeled

• Section 6: Potential Health Effects

• Section 7: Flammability Assessment

### FINAL July 2, 2015 2 • Section 8: Asphyxiation Assessment

• Section 9: End-Use Exposure Assessment

• Section 10: Occupational Exposure Assessment

• Section 11: General Population Exposure Assessment

• Section 12: References



### 2. SUMMARY OF RESULTS
R-449A is recommended for SNAP approval for the ref rigerated transport end-use, specifically in trucks and trailers. 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 t o the ozone layer, has lower climate impact, and a sh orter atmospheric lifetime. The components of R-449 A 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 subs tances is not a concern. In addition, because R-449 A is considered to be nonflammable, the proposed substit ute is not expected to present a flammability conce rn. It is expected that the manufacturer’s safety data sheet (SDS) for R-449A and good manufacturing practices will be adhered to, and appropriate safet y and personal protective equipment (PPE) (e.g., protective gloves, tightly sealed goggles, protecti ve work clothing, and suitable respiratory protecti on in case of leakage or insufficient ventilation) consis tent with Occupational Safety and Health Administra tion (OSHA) guidelines will be used during manufacture, servicing, and disposal of refrigerated transport u nits using R-449A. In addition, it is expected that leak detectors wil l be installed inside refrigerated transport contai ners and container doors will be open during end-use to prev ent significant exposure to R-449A in the case of catastrophic leakage. Because refrigerated transpor t units are to be installed in locations with adequ ate space and/or ventilation (i.e., outdoors) in accord ance with EPA recommendations and the equipment maintenance manuals for R-449A in the refrigerated transport end-use, significant toxicity risk to consumers is also unlikely.
Additional safeguards, including specified refriger ant concentration limits (RCL) of R-449A and its components, are also provided by adherence to indus try standards including American Society of Heating

, Refrigerating and Air-Conditioning Engineers (ASHRA E) Standards 15, 1 

### 34, 2 

### and 62. 3



### 3. ATMOSPHERIC ASSESSMENT
This section presents an assessment of the potentia l risks to atmospheric integrity posed by the use o f R449A in refrigerated transport. The ozone depletion potential (ODP), global warming potential (GWP), a nd atmospheric lifetime (ALT) of the proposed substitu te are presented in 

### Error! Reference source not found.

. The proposed substitute is substantially less harmf ul to the ozone layer, has lower climate impact, an d a shorter ALT when compared to refrigerants such as C FC-12, R-502, and HCFC-22. In addition, R-449A also has lower climate impact and a shorter ALT tha n those predicted for other substitutes examined in the Background Document as well as commonly utilized re frigerants in refrigerated transport, R-404A, R-

1 Safety Standard for Refrigeration Systems ASHRAE St andard 15 establishes safeguards for life, limb, he alth, and property and prescribes safety requirements.

2 Designation and Safety Classification of Refrigeran ts ASHRAE Standard 34 establishes a uniform system for assigning reference numbers, safety classifications, and refrigerant co ncentration limits to refrigerants. Safety classif ications based on toxicity and flammability data are included.
3 Ventilation for Acceptable Indoor Air Quality ASHRA E Standard 62 establishes minimum ventilation rates and other measures intended to provide indoor air quality that is acce ptable to human occupants and that minimizes advers e health effects.

### FINAL July 2, 2015 3 507A, and R-407C. Thus, EPA believes that the use o f R-449A would result in substantially less harm to the climate and ozone layer than the continued use of ODS and other commonly used refrigerants.
Table 2. Atmospheric Impacts of R-449A Components Compared to Other Refrigerants Used in Refrigerated Transport

Refrigerant Ozone Depleting Potential (ODP) a Global Warming Potential (GWP) b Atmospheric Lifetime in Years (ALT) b
R

- 449A 0 1,39 7 NA c Individual Components HFC

- 32 0 675 4.9 HFC

- 125 0 3,500 29 HFC

- 134a 0 1,430 14 HFO

- 1234yf 0 4 d 11 days d CFC

- 12 0.82 10,900 100 R

- 502 e 0.2 4,650 NA f HCFC

- 22 0.13 1,810 12 a R

- 404A g 0 3,922 NA h R

- 507A i 0 3,985 NA j R

- 407C k 0 1,774 NA l

a WMO 2010 Scientific Assessment Report (2011)

b IPCC 4 th Assessment Report (Forster et al. 2007)

c Atmospheric lifetimes are not given for blends, be cause the components separate in the atmosphere. Th e ALT for the individual components are listed in the table.

d Papadimitriou et al. (2007)

e R-502 is a blend consisting of HCFC-22 (49%) and CF C-115 (51%).

f Atmospheric lifetimes are not given for blends, be cause the components separate in the atmosphere. Th e ALT for HCFC-22 is 12 years and the ALT for CFC-115 is 1,700 years (IPCC 4 th Assessment Report [Forster et al. 2007]).

g R-404A is a blend consisting of HFC-143a (52%), HF C-125 (44%) and HFC-134a (4%).

h Atmospheric lifetimes are not given for blends, be cause the components separate in the atmosphere. Th e ALT for HFC-143a is 52 years, the ALT for HFC-125 is 29 years, and the ALT for HFC-13 4a is 14 years (IPCC 4 th Assessment Report [Forster et al. 2007]).

i R-507A is a blend consisting of HFC-125 (50%) and HFC-143a (50%). j Atmospheric lifetimes are not given for blends, be cause the components separate in the atmosphere. Th e ALT for HFC-125 is 29 years and ALT for HFC-143a is 52 years (IPCC 4 th Assessment Report [Forster et al. 2007]).

k R-407C is a blend consisting of HFC-32 (29%), HFC- 125 (25%) and HFC-134a (52%).

l Atmospheric lifetimes are not given for blends, be cause the components separate in the atmosphere. Th e ALT for HFC-32 is 4.9 years, the ALT for HFC-125 is 29 years, and the ALT for HFC-134a i s 14 years (IPCC 4 th Assessment Report [Forster et al. 2007]).



### 4. VOLATILE ORGANIC COMPOUND ASSESSMENT The components of R-449A (i.e., HFC-32, HFC-125, HF C-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-449A are not a concern.



### 5. DISCUSSION OF END-USE SCENARIOS MODELED R-449A has been proposed for use in refrigerated tr ansport units. As provided by the submitter, the ty pical and maximum charge sizes for R-449A in trucks and t railers are listed in Table 3.
Table 3. Typical and Maximum Charge Sizes for Vario us R-449A End-Uses and Applications

End-Use Application Typical Charge Size (kg) Maximum Charge Size

(kg)
Refrigerated Transport Trucks 2 5 Trailers 7 15


### To evaluate potential end-use exposures for R-449A in refrigerated transport units, this risk screen examines a scenario in which a catastrophic leak of refrigerant occurs while personnel are inside the refrigerated transport container and the doors to t he container are closed. A more reasonable worst-ca se

### FINAL July 2, 2015 4 scenario for this assessment would consider the cat astrophic leak of refrigerant occurring while the container doors are open, because EPA expects the r efrigerated container doors to be open while person nel are present inside the container at end-use (e.g., during loading and unloading of refrigerated goods)

. However, the limitations of the box model used for this assessment do not allow consideration of this scenario; calculating the concentration of R-449A i n the container as it exchanges with the warm, outs ide air through the open door would require more comple x computational fluid dynamics modeling.
Given these limitations, the risk screen evaluates a more unlikely scenario, in which it is assumed th at the full charge of the refrigerated transport unit is e mitted over the course of one minute into the refri gerated container with the doors closed. Although R-449A is denser than air, a vertical concentration gradient is not assumed, because when the full charge is releas ed, the presence of ventilation and the high pressu re operating conditions of the refrigerant are expecte d to disperse the proposed substitute evenly and immediately throughout the refrigerated transport c ontainer. It is assumed that an individual is prese nt at the start of the leak and remains in the container until the charge is completely released. Furthermore, this risk screen evaluates a refrigera ted transport unit with a ventilation rate of 25 m 3 

### /hr, a lower ventilation rate appropriate for less perisha ble produce (perishable items require a higher vent ilation rate up to 60 m 3 

### /hr) (Brecht et. al 2000). Hence, based on suggeste d ventilation rates for refrigerated transport units for various types of produce, this analysis conservatively assumes a ventilation rate of 25

m 3 

### /hr. 4 

### Table 4 details the end-use modeling assumptions u sed in Sections 8 and 9.
Table 4. End-Use Scenario Model Assumptions

Parameter Assumptions (Trucks) Assumptions (Trailers) Refrigerated Transport Container Trucks Trailers Charge Size (kg) 2; 5 7; 15 Length of Release (minutes) 1 1 Container Size (volume

- m 3 ) 78 (2, 76 0 ft 3 ) a 100 (3,530 ft 3 ) b Room Ventilation (m 3 /hr) 25 25 Vertical Concentration Gradient No No

a Specific information was not available regarding th e sizes of the refrigerated transport trucks. Thus, a standard 26 ft. (7.9 m) refrigerated truck was used for this scenar io, with a height of 12.5 ft (3.8 m) and a width of 8.5 ft (2.6 m) (C.H. Robinson, 2012).

b According to the United Nations Environmental Progr amme (UNEP), trailers have box volumes of approxima tely 100 m 3 (UNEP 2010).



### EPA recognizes that refrigerated transport units ma y be placed in a variety of containers with differe nt sizes and ventilation rates. When units are install ed in smaller containers, there is a higher risk fo r asphyxiation or significant exposure. To address th is variability in container volumes and charge size s for refrigerated transport units, this risk screen inco rporates threshold analyses in addition to the wors t-case scenario modeling. The threshold analyses are perfo rmed in order to determine the container size and charge size requirements that ensure that the use o f R-449A in refrigerated transport does not present risk to end-users or servicing technicians.



### 6. POTENTIAL HEALTH EFFECTS
To assess potential health risks from exposure to t he proposed substitute in refrigerated transport un its, EPA identified the relevant toxicity threshold valu es for comparison to modeled exposure concentration s for different scenarios. R-449A is listed under saf ety group A1 with a RCL of 100,000 ppm (ASHRAE 2015). ASHRAE 34 RCLs are intended to reduce the ri sks of acute toxicity, asphyxiation, and flammability hazards in normally occupied, enclosed spaces during refrigerant use, and protect end-use rs from the potential dangers of a catastrophic leak f rom a refrigeration unit (ASHRAE 2010b). ASHRAE

4 Ventilation rates range from 0 to 60 m 3 /hr depending on the type of good that is transport ed (Hamburg Süd 2010).

### FINAL July 2, 2015 5 Standard 15 implements the aforementioned standard, requiring that “the concentration of refrigerant i n an enclosed space following a complete discharge of a high-probability system shall not exceed the RCL” (ASHRAE 2010a). As such, this risk screen reference s the proposed RCL for R-449A, hypoxia no observed adverse effect level (NOAEL), and exposure limits, as an additional, conservative limit to en sure that significant asphyxiation and end-use exposure risks, respectively, do not occur. For the occupational exposure analysis, potential r isks from chronic and acute worker exposure were evaluated by comparing exposure concentrations to a vailable occupational exposure limits. Potential r isks of chronic worker exposure were evaluated using wor kplace guidance levels (WGLs), such as Workplace Environmental Exposure Levels (WEELs). Risks from potential short-term consumer exposures were evaluated by comparing exposure concentrations to e mergency guidance levels (EGLs). In the absence of an established short-term exposure limit (STEL), ac ute exposure guideline level (AEGL), or emergency response planning guideline (ERPG) for R-449A, pote ntial short-term, end-use exposures were evaluated on a component basis (i.e., HFC-32, HFC-125, HFC-13 4a and HFO-1234yf). Table 5 lists the relevant toxicity limits for R-449A and its components and i s followed by Table 6, which provides an explanatio n of each toxicity limit. EPA’s approach for identify ing or developing these values is discussed in Chap ter 3 of the Background Document.

Table 5. Exposure Limits of R-449A Components

R-449A Component WGL

(Long-term Exposure) ppm EGL

(Short-term Exposure) ppm Refrigerant Concentration Limit (RCL) ppm R

- 449A 830 (8

- hour AEL) 2,490 (15

- min STEL) a 100,000 Individual Components HFC

- 32 1,000 (8

- hour WEEL) 3,000 (15

- min STEL) b 36,000 HFC

- 125 1,000 (8

- hour WEEL) 3,000 (15

- min STEL) c 75,000
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) d 101,000 e

a Neither the American Conference of Governmental Ind ustrial Hygienists (ACGIH) nor the American Industr ial Hygiene Association (AIHA) recommend ceiling or short term exposure limits for the blend R-449A. A STEL for R-449A of 2,490 ppm w as developed by EPA based on the 830 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. [S TEL] = [AEL] x 3 = 830 ppm x 3 ≈ 2,490 ppm

b Neither ACGIH nor AIHA recommend ceiling or short t erm exposure limits for HFC-32. A STEL for HFC-32 o f 3,000 ppm was developed by EPA based on the 1,000 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. [S TEL] = [AEL] x 3 = 1,000 ppm x 3 ≈ 3,000 ppm.

c Neither ACGIH nor AIHA recommend ceiling or short term exposure limits for HFC-125. A STEL for HFC-12 5 of 3,000 ppm was developed by EPA based on the 1,000 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. [S TEL] = [AEL] x 3 = 1,000 ppm x 3 ≈ 3,000 ppm.

d 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. T he STEL was estimated as three to five times the AE L, 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

e Although a RCL has not been proposed for HFO-1234yf , the recommended ATEL for HFO-1234yf is 101,000 pp m (DuPont Fluoroproducts 2014).

### FINAL July 2, 2015 6 Table 6. Explanation of Exposure Limit-Related Term inology a Organization Definition OSHA Occupational Safety and Health Administration NIOSH National Institute for Occupational Safety and Health ACGIH American Conference of Governmental Industrial Hygi enists 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 (OD L), and Flammable Concentration Limit (FCL). Determination assumes fu ll vaporization with no removal by ventilation, dissolution, reaction, o r decomposition and complete mixing of refrigerant in the space to whic h it is released. ATEL Acute Toxicity Exposure Limit The ATEL is the refrigerant concentration limit int ended to reduce the risks of acute toxicity hazards in normally occupie d, enclosed spaces according to ASHRAE Standard 34. The ATEL includes consideration of mortality, cardiac sensitization, anesthetic or cen tral nervous system effects and other escape impairing effects and perm anent injury. The ATEL is similar to the Immediately Dangerous to Lif e or Health (IDLH) concentrations set by NIOSH. STEL Short

- Term Exposure Limit A 15

- mi nute time

- weighted average (TWA) exposure that should not be exceeded during a workday, even if the 8-hour TWA i s within the threshold limit value-time weighted average (TLV–TW A), set by ACGIH.

AEGL b,c Acute Exposure Guideline

Level 1 AEGL

- 1 is the airbo rne concentration (expressed as ppm or mg/m 3 ) of a substance above which it is predicted that the gene ral population, including susceptible individuals, could experience notable discomfort, irritation, or certain asymptomatic nonsensory effe cts. However, the effects are not disabling and are transient and rev ersible upon cessation of exposure. Acute Exposure Guideline Level 2 AEGL

- 2 is the airborne concentration (expressed as ppm or mg/m 3 ) of a substance above which it is predicted that the gene ral 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 o r mg/m 3 ) of a substance above which it is predicted that the gene ral population, including susceptible individuals, could experience life-threatening health effects or death. Long

- Term Exposu re 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 ag ainst acute and chronic health effects, this limit is based on repe ated daily exposures over a working lifetime and averaged over an 8-hour workday. TLV

- TWA Threshold Limit Value

– Time

Weighted Average T he 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 li fetime 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 fr om 10 minutes to 8 hours.

### FINAL July 2, 2015 7 According to the SDS, exposure to R-449A may be haz ardous if inhalation, skin contact, or eye contact with the proposed substitute occurs. The most likel y pathway of exposure is through inhalation. R-449A 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 sen ses, and also unconsciousness. Under some circumstances of over-exposure (i.e., oxygen levels fall below 6 percent by volume), death may occur.
If inhaled, R-449A can cause symptoms such as light -headedness, dizziness, confusion, incoordination, drowsiness, unconsciousness, and anesthetic effects . Excessive inhalation of R-449A may also result in an irregular heartbeat or death, due to cardiac effect s. If R-449A is inhaled, person(s) should be immediate ly removed from the contaminated space and exposed to fresh air. In accordance with the SDS, EPA furth er recommends that if breathing is difficult or irr egular, person(s) should be given oxygen, provided a qualif ied operator is present, and medical attention be sought. Exposures of R-449A to the skin may cause f rostbite. In the case of dermal exposure, the SDS f or R-449A recommends that person(s) immediately wash t he 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 attentio n immediately. Exposures of R-449A to the eyes could cause eye irritation. In case of ocular exposure, t he SDS for R-449A recommends that person(s) immediatel y 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 pr oposed substitute is contained in the public docket for this decision. These risks and procedures after exposure are simil ar for other common refrigerants. The potential health effects of R-449A can be minimized by following the exposure guidelines, and ventilat ion and PPE recommendations outlined in the SDS for R-4 49A and this risk screen.



### 7. FLAMMABILITY ASSESSMENT
R-449A is classified as an A1 refrigerant by ASHRAE , and is considered to be nonflammable (DuPont Fluoroproducts 2014; ASHRAE 2015). Based on this cl assification, manufacture, servicing, and use of R449A is not expected to present a flammability risk in the refrigerated transport end-use.



### 8. ASPHYXIATION ASSESSMENT
The risk of asphyxiation for the reasonable worst-c ase scenario described in Section 5 was investigate d for R-449A. In this section, risk of asphyxiation is as sessed in three ways: 1) modeling the oxygen concentration under the maximum charge size and con tainer size specified in the worst-case scenario, 2 ) performing a threshold analysis of the minimum char ge size needed to cause an asphyxiation risk in the container size specified in the worst-case scenario , and 3) performing a threshold analysis of the min imum container size needed to cause an asphyxiation risk with the maximum charge size specified in the wors tcase scenario. This analysis does not consider vent ilation or conditions that are likely to occur that would increase oxygen levels to which individuals would b e exposed, such as open container doors, which allo w air to flow in and out. Additionally, as specified in Section 5, the worst-case scenario does not assu me a vertical concentration gradient. If the proposed su bstitute passes the screening analysis with these restrictive assumptions in place, it can be reasona bly assumed that no risks of asphyxiation will be p resent under real-world conditions. The results of the asp hyxiation assessment are summarized in Table 7 belo w. Table 7. Asphyxiation Assessment a Refrigerated Transport Application Scenario Charge Size (kg) Effective

Container Size (m 3 ) Percent

Oxygen Concentration b Trucks Scenario 1a: Maximum Charge Size 5 78 (2,760 ft 3 ) 21%

### FINAL July 2, 2015 8 Trailers Scenario 1b: Maximum Charge Size 15 100 (3 ,530 ft 3 ) 20% Trucks Threshold Analysis 1a: Charge Size 120 78 (2,760 ft 3 )

12% Trailers Threshold Analysis 1b: Charge Size 150 100 (3,530 ft 3 ) Trucks Threshold Analysis 2a: Container Size 5 3.3 (120 ft 3 ) Trailers Threshold Analysis 2b: Container Size 15 9.8 (350 ft 3 )
Bold font indicates modeling results.

a Cells highlighted in green are the scenarios in wh ich the charge and container sizes evaluated in thi s risk screen are acceptable according to the threshold analysis or the scenarios with accept able oxygen concentrations, given various modeling assumption options.

b The typical concentration of oxygen in air is cons idered to be 21 percent (Mackenzie & Mackenzie 1995 ).


### In order for a risk of asphyxiation to occur, the n ormal concentration of oxygen in air (21 percent) m ust be reduced to 12 percent. 5 

### Based on the worst-case scenario modeling for R-44 9A, a release of the maximum charge sizes indicated by the submitter in trucks a nd trailers (i.e., 5 kg and 15 kg, respectively) do es not present a significant risk of asphyxiation. This mo deling does not take into account any ventilation w hich is likely to occur, such as open container doors th at allow air to flow in and out, as mentioned above . Thus, the actual asphyxiation risk to personnel is likely to be even smaller than modeled. For the asphyxiation threshold analyses shown in Error! Reference source not found. , the conditions at which an asphyxiation concern would exist were dete rmined.

• Within a container size of 78 m 3 

### (2,760 ft 3 

### ), as shown under Threshold Analysis 1a, the charge size of the R-449A refrigerated truck unit would have to be at least 120 kg for asphyxiation to be a concern, which is twenty-four times greater than th e maximum charge size indicated by the submitter for trucks (i.e., 5 kg).

• As shown under Threshold Analysis 1b, the charge si ze of the R-449A refrigerated trailer unit in a 100 m 3 

### container would have to be at least 150 kg for asp hyxiation to be a concern, which is ten times greater than the maximum charge size indicate d by the submitter for trailers (i.e., 15 kg).

• In order for a risk of asphyxiation to occur from t he release of a 5 kg refrigerated truck unit, the volume of the container would have to be approximat ely 3.3 m 3 

### (120 ft 3 

### ), or approximately twenty-four times smaller than the typical truck si ze indicated by the submitter (see Threshold Analysis 2a).

• Using the largest charge size of 15 kg for refriger ated trailers, as shown under Threshold Analysis 2b, the volume of the container would have to be ap proximately 9.8 m 3 

### (350 ft 3 

### ) or approximately ten times smaller than the typical trailer containe r size indicated by the submitter for asphyxiation to be of concern.
Based on the modeling results and threshold analysi s in Table 7, EPA does not believe that the use of R449A in refrigerated transport poses a significant risk of asphyxiation or impaired coordination to personnel, provided systems are installed in approp riate spaces according to guidelines from the manufacturer and the SDS for R-449A.



### 9. END-USE EXPOSURE ASSESSMENT
This section presents estimates of potential end-us er exposures to R-449A and each of its chemical constituents in the event of a catastrophic release from the proposed substitute’s use in refrigerated transport units. An end-use exposure analysis was p erformed to examine potential catastrophic releases of R-449A under the scenario outlined in Section 5. This end-use exposure assessment examines a scenari o in which personnel are located inside the refrigerated transport unit containing goods; such scenarios are expected to occur while the container doors are open. When the container doors are opened, a st ack effect exists from the presence of the denser, cold

5 Twelve percent oxygen in air is the NOAEL for hypo xia (ICF 1997).

### FINAL July 2, 2015 9 air coming into contact with the warm, moist air ou tside. This effect will cause the colder air to flo w outside of the container and become replaced by the warm, outside air through infiltration. Therefore, EPA expects that if a release of the proposed substitut e occurs while personnel are present inside the refrigerated transport container (e.g., during load ing and unloading of refrigerated goods), the conta iner doors would be open, increasing the air exchange ra te inside of the unit and also resulting in diffusi on of any R-449A to flow towards the outside of the conta iner. To simulate a worst-case scenario, the catastrophic release of the entire charge of the unit into the refrigerated container was modeled. The estimated e xposures are conservative, as the analysis assumes that a catastrophic release occurs while the refrigerate d transport container doors are closed and also doe s not consider other variables that would reduce the leve ls to which individuals would be exposed. The analy sis was undertaken to determine the 15-minute exposures for R-449A, which were then compared to the standard toxicity limits presented in Table 5 to as sess the risk to end-users. Modeling results are pr esented in Table 8a.
Table 8a. End-Use Exposure Assessment for R-449A C omponents a
Refrigerated Transport Containers R-449A

Component Charge

Size (kg) Container

Size (m 3 ) 15-min TWA

End-Use Exposure (ppm) 15-minute Short

Term Exposure Limit b (ppm) Refrigeration

Concentration Limit (RCL)

Trucks HFC

- 32

2 78 2, 600 3,000 36,000

HFC

- 125 1,140 3,000 75,000 HFC

- 134a 1,400 8,000 50,000 HFO

- 1234yf 1,230 1,500 c 101,000 d HFC

- 32

5 78 6, 500 3,000 36,000 HFC

- 125 2, 8 6 0 3,000 75,000 HFC

- 134a 3,500 8,000 50,000 HFO

- 1234yf 3,090 1,500 c 101,000 d

Trailers HFC

- 32

7 100 7, 1 9 0 3,000 36,000

HFC

- 125 3, 1 7 0 3,000 75,000 HFC

- 134a 3, 8 8 0 8,000 50,000 HFO

- 1234yf 3,410 1,500 c 101,000 d HFC

- 32

15 100 15, 400 3,000 36,000 HFC

- 125 6, 7 8 0 3,000 75,000 HFC

- 134a 8, 30 0 8,000 50,000 HFO

- 1234yf 7, 32 0 1,500 c 101,000 d
Bold font indicates modeling results.

a Cells highlighted in green are the scenarios with a cceptable exposure levels given various modeling as sumption options.

b See Table 5 for more information

c EPA-derived STEL (see Table 5).

d ATEL for HFO-1234yf is 101,000 ppm; see Table 5 fo r more information.



### Under the worst-case scenarios described in Section 5 for refrigerated transport systems in trucks and trailers, catastrophic releases of the typical and maximum charge sizes of R-449A were modeled. Although approximately half of the exposure estimat es for the worst-case scenarios exceed the STEL for R-449A components (i.e., 3,000 ppm for HFC-32 and H FC-125, 8,000 ppm for HFC-134a, and 1,500 ppm for HFO-1234yf) (see Table 8a), the STEL is a conse rvatively-derived exposure limit that is intended t o protect workers in an occupational setting in which they are exposed to these chemicals on a daily bas is. The STEL values do not represent limits for a singl e exposure in a lifetime. These modeled exposures a re one-time exposures following a catastrophic release of refrigerant, so exceedances of the STEL values do not necessarily indicate a significant risk of harm to end-users. The effect of a one-time exposure ca n be more accurately evaluated by comparing the modeled exposure concentrations to the RCL and ATEL, which are limits intended to reduce the risks of ac ute toxicity hazards in normally occupied, enclosed

### FINAL July 2, 2015 10 spaces according to ASHRAE Standard 34 (see Table 6 ). All of the modeled exposure estimates are significantly lower than the RCL for HFC-32, HFC-12 5, and HFC-134a, (i.e., 36,000, 75,000, and 50,000 ppm, respectively), as well as the ATEL for HFO-123 4yf (i.e., 101,000 ppm). 6 

### Furthermore, the estimated exposures for R-449A in each of these scenarios are also significantly lower than the RCL for R-449A (i.e., 100,000 ppm). Because the modeling was done using a conservative worst-case scenario where the refrigerated transport container doors are closed, and because normally personnel would be exposed in a situation where the doors are open with significant ly higher ventilation levels, personnel exposure to the proposed substitute at end-use is not expected to r each the modeled concentrations shown in Table 8a. Therefore, end-use exposure is not considered to be a significant risk.
A threshold analysis was performed to determine the combinations of charge sizes and container sizes w ith a 25 m 3 

### /hr ventilation rate that would avoid end-use expos ures above the STEL for components of R449A. The results from the threshold analyses are u sed to establish general guidelines for choosing an effective container size and charge size such that the use of R-449A in refrigerated transport units d oes not present risk to end-users or servicing technicians. These estimated charge and container sizes are fai rly conservative as the analysis does not consider open container doors and other variables that would red uce the levels to which individuals would be exposed. T he results of the threshold analyses are presented in Table 8b.
Table 8b. End-Use Exposure Threshold Analysis for R -449A Components Refrigerated Transport Container Scenario Charge Size (kg) Container Size (m 3 )

Trucks Threshold Analysis 1a: Charge Size 2.3 78 (2,760 ft 3 )

Threshold Analysis 1b: Container Size 5 170 (6,140 ft 3 )

Trailers Threshold Analysis 2a: Charge Size 2.9 100 (3,530 ft 3 )

Threshold Analysis 2b: Container Size 15 530 (18,700 ft 3 )
Bold font indicates modeling results.

a EPA-derived STEL (see Table 5). 

### Based on these results, for a minimum container vol ume of 78 m 3 

### (2,760 ft 3 

### ), end-use exposure would not exceed the STEL of any components of R-449A as long as the charge size does not exceed 2.3 kg (see Threshold Analysis 1a in Table 8b) and for the maxi mum proposed charge sizes in trucks and trailers (i .e., 5 and 15 kg, respectively) exposure would not be a concern if the refrigeration unit is installed in a container of effective volume of at least 170 m 3 

### (6,140 ft 3 

### ) and 530 m 3 

### (18,700 ft 3 

### ), respectively (see Threshold Analyses 1b and 2b in Table 8b). As shown in Table 8b, these recommended minimum container sizes vary in direct correlation with cha rge size, and are more conservative than the intend ed charge sizes provided by the submitter. However, th e modeling results presented in Table 8a and 8b are derived using the STELs for R-449A components (i.e. , 3,000 ppm for HFC-32 and HFC-125, 8,000 ppm for HFC-134a, and 1,500 ppm for HFO-1234yf) and ref lects conditions that are assumed to be a worst-cas e scenario, as described in Section 5. Infiltration rates through the opening of a refrige rated truck container have been measured to be approximately 2,520 m 3 

### /hr, which is roughly 100 times the ventilation rat es used in the threshold analyses (Bonjour et. al 2011). As previously discussed, EPA expects the refrigerated container doors to be ope n while personnel are present inside the container at end-use, increasing the air exchange rate inside o f the unit and also encouraging any R-449A to flow toward s the outside air. Therefore, under a reasonable worst-case scenario where the refrigerated containe r doors are open, the exposures shown in the modeli ng

6 Although a RCL has not been proposed for HFO-1234yf , the recommended ATEL for HFO-1234yf is 101,000 pp m (DuPont Fluoroproducts 2014). The ATEL is a refrigerant con centration limit intended to reduce the risks of ac ute toxicity hazards in normally occupied, enclosed spaces according to ASH RAE Standard 34.

### FINAL July 2, 2015 11 results (see Tables 8a and 8b) are unlikely. Because refrigerated transport units using the prop osed substitute were modeled using a conservative, worst-case scenario where the refrigerated transpor t container doors are closed, personnel exposure ab ove the proposed substitute’s STEL is unlikely. However , these potential exceedances emphasize the importance associated with proper equipment use, em ployment of engineering controls to limit releases and/or exposures, and the need for workforce traini ng. To prevent exposure and reduce the risk of acut e toxicity hazards during larger releases in any loca tion where an R-449A system is installed, EPA recommends that the proposed RCL for R-449A (i.e., 100,000 ppm or 370 g/m 3 

### ) and the RCL for the individual components (or ATEL for HFO-1234yf) are not exceeded and that proper leak protection devices are in place. In addition, EPA recommends t he installation of refrigerant detection monitors o n both ends of the refrigerated container, especially near the refrigeration system unit, and ensure the doors to the refrigerated container are open while person nel are inside.
EPA also recommends that warning labels are present in the refrigerated transport container indicating that R-449A refrigerant is in use and can cause suffocat ion, injury, or death. An example of this warning l abel would read: “WARNING: R-449A gas can cause injury o r death. Ventilate the area before entering. A high R-449A concentration can occur in this area an d can cause suffocation.” Training materials and an operations manual describing procedures for proper use of the equipment, safety guidelines for handlin g R-449A, and safety training is required for all per sonnel operating and servicing the refrigerated tra nsport unit. These procedures and guidelines should be ack nowledged and followed to mitigate exposure in case of R-449A leakage in refrigerated transport units.



### 10. OCCUPATIONAL EXPOSURE ASSESSMENT
This section assesses potential exposures to worker s during manufacture, charging and servicing, and disposal of R-449A refrigerated transport equipment . To ensure that use of the proposed substitute in refrigerated transport does not pose an unacceptabl e risk to workers during charging, servicing, and disposal, occupational exposure modeling was perfor med using a box-model approach. For a detailed description of the methodology used for this screen ing assessment, the reader is referred to the occupational exposure and hazard analysis described in Chapter 5 of the Background Document.
Estimates of refrigerant release per event for vari ous release scenarios were obtained from the Vintag ing Model. 7 

### To determine the estimated level of occupational e xposure for a constituent in a blend, the total anticipated release rate of the refrigerant is mult iplied by the weight percent composition of each compound in the blend. For charging, servicing, and disposal activities, the release rate per event wa s multiplied by the number of events estimated to occ ur over a workday. During charging and servicing, t he release per event was conservatively assumed to ran ge between 0.6 percent and 8 percent of the equipme nt charge, respectively. For equipment charging and servicing, the number of events per workday was assumed to equal the maximum number of units antici pated to be serviced in one day (i.e., eight units divided by eight hours per workday for refrigerated transport units in trucks and trailers) (see Secti on 10.2). For equipment disposal of refrigerated truck and tr ailer systems, the release per event was conservati vely assumed to be 100 percent of the equipment charge ( representing a catastrophic release). It was assume d that 10 units are disposed of during an 8-hour work day; however, it was assumed that of the ten units

, only the last unit per workday would experience the catastrophic release (i.e., 100 percent). The rema ining 9 units were assumed to release only an incidental amount of refrigerant (i.e., 1 percent per unit) fr om the

7 ICF International maintains the Vintaging Model fo r EPA in order to simulate the aggregate impacts of the ODS phaseout on the use and emissions of various ODS and their substitu tes over a period of several years across 60 differ ent end-uses. The model tracks the use and emissions of various compounds f or the annual vintages of new equipment that enter service in each end-use. The vintage of each type of equipment determines su ch factors as leak rate, charge size, number of uni ts in operation, and the initial ODS substance that the equipment contained.

### FINAL July 2, 2015 12 connecting and disconnecting of lines, as it is lik ely that if a worker was exposed to the entire char ge of a system during disposal activities, they would immed iately stop working, clear the area until all refri gerant has been removed from the space (e.g., through vent ilation), and adhere to the exposure procedures recommended in the SDS for the proposed substitute (see Section 10.3).
The modeled exposure concentrations for both scenar ios were compared to STELs at charging and servicing in Table 9 and long-term exposure limits at disposal in Table 10.

### FINAL July 2, 2015 13 10.1 Occupational Exposure at Manufacture

During manufacture of the components and blending o f R-449A, the SDS for each component (i.e., HFC32, HFC-125, HFC-134a and HFO-1234yf) should be ref erenced and proper engineering controls and PPE used.
Refrigerant quality control testing may also result in release of de minimus quantities of refrigerant, which would typically be to exhaust ducts or fume hoods. To prevent significant exposure if such leaks occur , engineering controls should be used, including no rmal and local ventilation (e.g., chemical hoods) and va por-in-air detection systems for standard manufactu ring procedures so workers can avoid physical contact wi th the refrigerant and to achieve emission control. In general, use of PPE consistent with OSHA guidelines is recommended, such as respiratory protection (including a self-contained breathing apparatus [SC BA] in case of insufficient ventilation), tightly s ealed goggles, and protective gloves (OSHA 1994).
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-449A 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 s torage temperature should be 40 ° C) in well-sealed receptacles and should not be allowed to contact op en flames, glowing metal surfaces, or electrical he ating elements. EPA believes that when proper handling an d disposal guidelines are followed, in accordance with both good industrial hygiene and manufacturing practices and the SDS for R-449A and its components, there is no significant risk to workers during the manufacture of R-449A.
10.2 Occupational Exposure at Charging and Servicin g Charging and servicing activities for refrigerated transport units are not expected to result in signi ficant worker exposure when certified technicians follow t he procedures outlined in the R-449A SDS and maintenance manual, undergo proper training, and we ar appropriate PPE (e.g., gloves and safety glasses ). Nevertheless, the potential occupational exposure d uring servicing was analyzed. The maximum 15- minute TWA exposures for each R-449A constituent we re estimated for the charging and servicing exposure scenario and compared to their respective STELs (see Table 9).
Table 9. Occupational Risk Assessment at Charging and Servicing for R-449A Components a
Refrigerated Transport Containers R-449A

Component Charge

Size (kg) 15

- min TWA Occupational

Exposure (ppm) 15-minute Short Term Exposure Limit b (ppm) Refrigeration

Concentration Limit (RCL) b Charging (0.6% release) Servicing

(8% release)

Trucks HFC

- 32

2 6.0 8 1 3,000 36,000

HFC

- 125 2.7 36 3,000 75,000 HFC

- 134a 3.3 44 8,000 50,000 HFO

- 1234yf 2.9 3 8 1,500 c 101,000 d HFC

- 32

5 15 20 0 3,000 36,000 HFC

- 125 6.7 89 3,000 75,000 HFC

- 134a 8.2 110 8,000 50,000 HFO

- 1234yf 7 .2 96 1,500 c 101,000 d

Trailers HFC

- 32

7 21 28 0 3,000 36,000

HFC

- 125 9.4 130 3,000 75,000 HFC

- 134a 11 15 0 8,000 50,000 HFO

- 1234yf 10 140 1,500 c 101,000 d HFC

- 32 15 4 6 610 3,000 36,000 HFC

- 125 20 270 3,000 75,000 HFC

- 134a 25 330 8,000 50,000

### FINAL July 2, 2015 14 HFO

- 1234yf 2 2 290 1,500 c 101,000 d
Bold font indicates modeling results.

a Cells highlighted in green are the scenarios with a cceptable exposure levels given various modeling as sumption options.

b See Table 5 for more information.

c EPA-derived STEL (see Table 5).

d ATEL for HFO-1234yf is 101,000 ppm; see Table 5 fo r more information.



### The anticipated 15-minute TWA exposures for the com ponents of R-449A are not anticipated to exceed their respective STELs (see Table 9). In addition, the estimated exposures were derived using conserva tive assumptions, and do not take into account the use o f ventilation or PPE. These types of systems are typically serviced by trained personnel using prope r industrial hygiene techniques and using proper engineering controls (e.g., local ventilation, refr igerant detectors, and alarm systems). Thus, EPA do es not believe that charging or servicing of refrigerated transport units containing R-449A present a signifi cant concern to workers.

10.3 Occupational Exposure at Disposal Disposal of R-449A in refrigerated transport units is expected to occur with limited frequency (approximately ten disposal events per day) at disp osal facilities with limited duration of exposure t o the installed refrigerant. Typically, potential exposur es to the refrigerant during recovery and disposal are expected to occur during activities related to deco mmissioning refrigeration systems (e.g., attaching of hoses associated with draining or otherwise dischar ging of refrigerant from the refrigeration units in to cylinders) and would be similar to those during ser vicing, because similar refrigerant charging and/or recovery equipment would be used (see Section 10.2 and Table 9 for information and modeling results related to exposure during servicing activities).
As shown in Table 9 in Section 10.2, exposures duri ng servicing (and therefore during typical disposal activities) are not anticipated to present a signif icant concern for workers. To model a worst-case sc enario during disposal, it was assumed that of the ten dis posal events, nine units are properly disposed of w ith only incidental releases of refrigerant (i.e., 1 pe rcent per unit) followed by the disposal of one uni t that results in a catastrophic release of refrigerant (i .e., 100 percent of the charge). Table 10 presents the maximum estimated 8-hour TWA occupational exposure levels for the constituents of R-449A during disposal.
Table 10. Occupational Risk Assessment at Disposal for R-449A Components a
Refrigerated Transport Containers R-449A

Component Charge

Size (kg) 8-hour TWA

Occupational Exposure (ppm) 8-hour Long

Term Exposure Limits (ppm) b Refrigeration

Concentration Limit (RCL)

Trucks HFC

- 32

2 160 1,000 36,000

HFC

- 125 70 1,000 75,000 HFC

- 134a 85 1,000 50,000 HFO

- 1234yf 75 500 101,000 c HFC

- 32

5 400 1,000 36,000 HFC

- 125 170 1,000 75,000 HFC

- 134a 210 1,000 50,000 HFO

- 1234yf 190 500 101,000 c

Trailers HFC

- 32

7 560 1,000 36,000

HFC

- 125 240 1,000 75,000 HFC

- 134a 300 1,000 50,000 HFO

- 1234yf 260 500 101,000 c HFC

- 32 15 1,190 1,000 36,000 HFC

- 125 520 1,000 75,000

### FINAL July 2, 2015 15 HFC

- 134a 640 1,000 50,000 HFO

- 1234yf 560 500 101,000 c Bold font indicates modeling results.

a Cells highlighted in green are the scenarios with a cceptable exposure levels given various modeling as sumption options.

b 8-hour WEEL

c ATEL for HFO-1234yf is 101,000 ppm; see Table 5 fo r more information.



### The results in Table 10 indicate that long-term (8- hour) worker exposure concentration during disposal is not likely to exceed the WEEL for components of R-4 49A in trucks and trailers with the exception of HFC-32 and HFO-1234yf in the maximum proposed charg e size in trailers (i.e., 15 kg). Although the modeling indicates that the worst-case disposal sce nario for the maximum proposed charge size in trail ers could exceed the WEEL for HFC-32, the estimated exp osures were derived using conservative assumptions (e.g., no mechanical or local exhaust v entilation), and represent a worst-case scenario wi th a low probability of occurrence. These types of syste ms are typically disposed of by Section 608-certifi ed personnel using proper industrial hygiene technique s to maximize recovery efficiency and limit release s, and there are already established standards of prac tice and training requirements that apply to fluori nated refrigerants to reduce exposures (and would therefo re extend to R-449A systems). It is also unlikely that workers would be exposed t o the unrecoverable portion of refrigerant during t he recovery process, and therefore anticipated exposur es would be approximately ten percent lower. For example, some of the refrigerant would likely be di ssolved in the refrigerant oil (which would be draw n out and separated from the recovered refrigerant) o r trapped within deeper parts of the refrigeration circuit (e.g., the accumulator or receiver) and wouldn’t be released until the system is actually dismantled l ater on in the disposal process (Oko-Recherche 2003).
Because anticipated occupational exposures could ex ceed the exposure limit for components of R-449A in one of the disposal release scenarios (i.e., traile r units of 15 kg charge size), the recommendations for proper engineering controls and PPE in the SDS for R-449A should be followed. Adequate ventilation should always be established during any use, handli ng, or storage of R-449A. If recovery and disposal is taking place in an enclosed space without any mecha nical ventilation, facilities should be cleared of nonessential personnel and technicians should wear a S CBA and other appropriate protective equipment. Engineering controls should include vapor-in air de tection systems and local exhaust ventilation durin g use of R-449A to prevent dispersion throughout the work place. In addition, an eye wash and safety shower should be near the manufacturing facility and locat ions where R-449A is stored and ready for use. In general, use of PPE is recommended, such as splash goggles, mechanical resistance gloves (e.g., oilrepellent or thermal resistance gloves) when handli ng cylinders and recovery equipment and chemicallyresistant gloves when handling the gas mixture (e.g ., butyl rubber, chlorinated polyethylene, or neopr ene). The installation of signage which warns room occupa nts to remain standing (as higher concentrations ar e likely to accumulate near the floor), not to enter recessed parts of the facility (e.g., maintenance c rawl spaces and below grade service areas), and exit the facility immediately should they hear the refriger ant detector alarm and/or smell the leaked refrigerant would further minimize toxicity risks. EPA believes that if proper handling and disposal guidelines are foll owed, in accordance with good industrial hygiene an d manufacturing practices and the SDS for R-449A, the re is no significant risk to workers during the manufacturing, installation, servicing, and disposa l of R-449A in refrigerated transport units.



### 11. GENERAL POPULATION EXPOSURE ASSESSMENT
R-449A 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 r efrigerated transport units. The proposed substitut e will be manufactured in a closed process and is proposed for use in closed systems; thus, significant relea ses are not anticipated. At room temperature, R-449A is a gas and, therefore, releases to ground or surfac e water are not anticipated, as R-449A is anticipated to dissipate into the atmosphere upon release to o utside

### FINAL July 2, 2015 16 air (i.e., because natural ventilation rates would be higher and there is no enclosed space to maintai n a high concentration of R-449A). Should air releases durin g manufacturing operations occur, engineering contr ols should be used (e.g., carbon absorption scrubbers) to collect R-449A and prevent the release of R-449A to the atmosphere. EPA believes that by using proper e ngineering controls and by following disposal and containment recommendations outlined in the propose d substitute’s SDS and this risk screen, exposure t o R-449A is not expected to pose a significant toxici ty risk to the general population.

### FINAL July 2, 2015 17 

### 12. REFERENCES

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

ANSI/ASHRAE. 2015. 2015 Supplement to Standard 34: Designation and Safety Classification of Refrigerants. American Society of Heating, Refriger ating and Air-Conditioning Engineers, Inc.

ANSI/ASHRAE. 2013a. Standard 62: Ventilation for Ac ceptable Indoor Air Quality. American Society of Heating, Refrigerating and Air-Conditioning Engi neers, Inc.

ANSI/ASHRAE. 2010a. Standard 15: Safety Standard fo r Refrigeration Systems. American Society of Heating, Refrigerating and Air-Conditioning Enginee rs, Inc.

ANSI/ASHRAE. 2010b. Standard 34: Designation and Sa fety Classification of Refrigerants. American Society of Heating, Refrigerating and Air-Condition ing Engineers, Inc.

Bonjour, J. Ducoulombier, M., and Sartre, V. 2011. Experimental Investigation of the Infiltration Heat Load During the Opening of a Refrigerated Truck Body. In ternational Institute of Refrigeration: Internation al Congress of Refrigeration. Available online at http ://bright-blue.eu/wp-content/uploads/2012/11/artike l392_DucoulombierSartreBonjour_revised_final.pdf

Brecht, P., Hinsch, T., Kader, A., and Thompson, J. 2000. Marine container transport of chilled perish able produce. University of California Agriculture and N atural Resources Publications: Oakland, CA.

C.H. Robinson Worldwide. 2012. Trailer Equipment Gu ide. Available online at: http://www.chrobinson.com/en/us/-/media/chrobinson/ news-pdf/truckloadequipmentguide.pdf.

DuPont Fluoroproducts. 2014. Opteon® XP40 for Use a s a Refrigerant. Significant New Alternatives Policy Program Submission to the United States Envi ronmental 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. Sc hulz 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 Fourt h Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marqu is, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. Cambridge University Press, Ca mbridge, United Kingdom and New York, NY, USA.

Gallagher, Glenn, Tao Zhan, Ying-Kuang Hsu, et. al. (CARB) 2013. “High-global Warming Potential Fgas Emissions in California: Comparison of Ambient- based versus Inventory-based Emission Estimates, and Implications of Refined Estimates.” Environ. Sci. Technol., 2014, 48 (2), pp 1084–1093. DOI: 10.1021/es403447v. Publication Date (Web): December 13, 2013. Copyright © 2013 American Chemical Society. Available at http://pubs.acs.org/doi/abs/1 0.1021/es403447v

Hamburg Süd. 2010. Reefer Guide. Available online a t http://www.hamburgsud.com/group/media/sharedmedia/d okumente/brochures/Reefer_guide.pdf

Hodnebrog, O., Etminan, M., Fuglestvedt, J. S., Mar ston, G., Myhre, G., Nielsen, C. J., Shine, K. P., Wallington, T. J. 2013. Global Warming Potentials a nd Radiative Efficiencies of Halocarbons and Related Compounds: A Comprehensive Review, Reviews of Geophysics, 51, 300-378, doi:10.1002/rog.20013.

### FINAL July 2, 2015 18 ICF. 1997. Physiological Effects of Alternative Fir e Protection Agents - Hypoxic Atmospheres Conference. Stephanie Skaggs prepared the proceedin gs of the conference held May 22, 1997 in New London, CT.

Kataoka, O., M. Yoshizawa, & T. Hirakawa 2000. “Al lowable Charge Limit of Flammable Refrigerants and Ventilation Requirements.” Daikin Industries. International Refrigeration and Air Conditioning Conference. Paper 506. Available online at: http:// docs.lib.purdue.edu/iracc/506

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

Oko-Recherche and Ecofys. 2003. “Establishing the L eakage Rates of Mobile Air Conditioners”. Available online at: http://www.oekorecherche.de/si tes/default/files/publikationen/leakage_rates_0.pdf

OSHA. 2004. “Safety and Health Topics: Isobutane.” February 2004. Available online at: http://www.osha.gov/dts/chemicalsampling/data/CH_24 7840.html

Papadimitriou, V., R.K. Talukdar, R.W. Portmann, A. R. Ravishankara, and J.B. Burkholder. 2007. CF 3 

### CF=CH 2 

### and (Z)-CF 3 

### CF=CHF: Temperature dependent OH rate coefficients and global warming potentials. Physical Chemistry Chemical Physics. 9: 1-13.

United Nations Environmental Programme. 2010. “2010 Report of the Refrigeration, Air Conditioning and Heat Pumps Technical Options Committee (RTOC) 2 006 Assessment. Available online at: http://acdext.gsfc.nasa.gov/Documents/O3_Assessments/Docs/WMO _2010/2010assessment/RTOC_2010_Assess ment_Report.pdf>

U.S. EPA. 2012. Acute Exposure Guidelines (AEGLs) D efinitions. Available online at: http://www.epa.gov/oppt/aegl/pubs/define.htm

U.S. EPA. 1994. Significant New Alternatives Polic y 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. Scie ntific Assessment of Ozone Depletion: 2010, Global Ozone Research and Monitoring Project-Report No. 52, 516 pp., Geneva, Switzerland.