Final

-- October 10 , 2014 1 

## Significant New Alternatives Policy Program Refrigeration and Air Conditioning Sector Risk Screen on Substitutes in Retail Food Refrigeration, Vending Machines, and Commercial Ice Machines
Substitute: R

- 450A

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 ODS

using sectors includin g: 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 EP A'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

- 450A as a substitute in the retail refrigeration (specifically, convenience stores, direct racks, indirect racks, remote condensing units, and stand

- alone display cases), vending machines, and commercial ice machines end

- uses. Table 1 presents the composition o f the proposed substitute.
Table 1 . Composition of R

- 450A and Potential Impurities

Constituent Chemical Formula CAS Number Concentration (Weight Percent) a 1,1,1,2

- Tetrafluoroethane (HFC

- 134a) CF 3 CH 2 F 811

- 97

- 2 42% Trans

- 1,3,3,3,

- Tetrafluoro

- 1

- propene (HFO

- 1234ze(E)) CHFCHCF 3 29118

- 24

- 9 58% Potential ImpuritiesFinal

-- October 10 , 2014 2 Constituent Chemical Formula CAS Number Concentration (Weight Percent) aFinal

-- October 10 , 2014 3 Constituent Chemical Formula CAS Number Concentration (Weight Percent) a

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 Scenario Modeled

 Section 6 : Potential Health Effects

 Section 7 : Flammability Assessment

 Section 8 : Asphyxi ation 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

- 450A is recommended for SNAP approval for the retail food refrigeration, vending machine, and commercial ice machine end

- uses. EPA's risk screen indicates that the use of the proposed substitute will be less harmful to the atmosphere than the continued use of CFC

- 12, R

- 502, and HCFC

- 22 , as well as oth er commonly used refrigerants, as it is less harmful to the ozone layer, has lower climate impact, and a shorter atmospheric lifetime. Neither of the components of R

- 450A are subject to volatile organic compound (VOC) regulations under the CAA (40 CFR 51.1 00(s)), so environmental impact from the release of these substances is not a concern. It is expected that the material safety data sheet (MSDS) for R

- 450A and good manufacturing practices will be adhered to. Additionally, it is expected that the appropria te 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 retail food refrigeration systems, vending machines, and commercial ice machines using R

- 450A. Because retail food refrigeration systems, vending machines, and commercial ice machines are to be installed in locations with adequate space and/or ventilation in accordance with EPA recommendations and the equipment maintenance manuals for R

-Final

-- October 10 , 2014 4 450A in each end

- use, significant toxicity risk to consumers i s also unlikely. In addition, because R

- 450A is considered to be nonflammable , the proposed substitute is not expected to present a flammability

concern. Additional safeguards, including specified refrigerant concentration limits (RCL) of R

- 450A components, are also provided by adherence to industry standards including American Society of Heating, Refrigerating and Air

- Conditioning Engineers (ASHRAE) Standards 15, 1 34, 2 and 62. 3



### 3. ATMOSPHERIC ASSESSMENT This section presents an assessment of th e potential risks to atmospheric integrity posed by the use of R

450A in retail food refrigeration, vending machines, and commercial ice machines. The ozone depletion potential (ODP), global warming potential (GWP), and atmospheric lifetime (ALT) of the p roposed substitute are presented in

1 Safety Standard for Refrigeration Systems ASHRAE Standard 15 establishes safeguards for life, limb, health, and property and prescribes safety requirements. 2 Designation and Safety Classification of Refrigerants ASHRAE Standard 34 is 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. 3 Ventilation for Acceptable Indoor Air Quality ASHRAE Standard 62 establishes minimum ventilation rates an d other measures intended to provide indoor air quality that is acceptable to human occupants and that minimizes adverse health effects.Final

-- October 10 , 2014 5 Table 2

. The proposed substitute is substantially less harmful to the ozone layer, has lower climate impact, and a shorter atmospheric lifetime when compared to refrigerants currently used in these end uses such as CFC

12, R

- 502, and HCFC

- 22. In addition, R

- 450A also has lower climate impact and a shorter atmospheric lifetime than those predicted for other substitutes examined in the Background Document as well as commonly utilized refrigerants HFC

- 134a, R

- 404A, R

- 507A, and R

- 407C. Thus, EPA believes that the use of R

- 450A would result in substantially less harm to the climate and ozone layer than the continued use of ODS and other commonly used refrigerants.Final

-- October 10 , 2014 6 Table 2 . Atmospheric Impacts of R

- 450A Components Compared to Other Retail Food Refrigerants Refrigerant Ozone Depleting Potential (ODP) a Global Warming Potential (GWP) b Atmospheric Lifetime in Years (ALT) R

- 450A 0 601 NA c Individual Components HFC

- 134a 0 1,430 14 b HFO

- 1234ze(E) 0 1 d 16.4 days d CFC

- 12 0.82 10,900 100 b R

- 502 e 0.2 4,650 NA f HCFC

- 22 0.13 1,810 12 a HFC

- 134a 0 1,430 14 b 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, because the components separate in the atmosphere. The ALT for HFC

- 134a is 14 years and the ALT for HFO

- 1234ze(E) is 16.4 days (IPCC 4 th Assessment Report [Forster et al. 2007], Hodnebrog, O. et al. [ 2013 ] ). d Hodnebrog, O. et al. ( 2013 )

e R

- 502 is a blend consisting of HCFC

- 22 (49%) and CFC

- 115 (51%). f Atmospheric lifetimes are not given for blends, because the components separate in the atmosphere. The 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%), HFC

- 125 (44%) and HFC

- 134a (4%). h Atmospheric lifetimes are not given for blends, because the components separate in the atmosphere. The ALT for HFC

- 143a is 52 years, the ALT for HFC

- 125 is 29 years, and the ALT for HFC

- 134a 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, because the components separate in the atmosphere. The 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, 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 4 th Assessment Report [Forster et al. 2007]).


### 4

. VOLATILE ORGANIC COMPOUND (VOC) ANALYSIS
HFC

- 134a and HFO

- 1234ze(E) are not volatile organic compounds (VOCs) according to CAA regulations (40 CFR 51.100(s)) due to their negligible photochemical reactivity

. Therefore, environmental impacts from the rele ase of HFC

- 134a and HFO

- 1234ze(E) as VOCs are not a concern.



### 5. DISCUSSION OF END

- USE SCENARIOS MODELED
The submission states that R

- 450A retail food refrigeration equipment will have typical charge sizes ranging from 0.9 kg for a stand

- alone, self

- contai ned display case to 300 kg for a direct rack system. For vending machines, the submission states that R

- 450A will have a typical charge size of 0.5 kg. Commercial ice machines are anticipated to have a typical charge size of 10 kg and a maximum charge size of 50 kg. The intended maximum and typical charge sizes for all of the proposed applications are listed in Table 3.Final

-- October 10 , 2014 7 Table 3 . Typical and Maximum Charge Sizes for Various R

- 450A End

- Uses and Applications
End
- Use Application Typical Charge Size (kg) Maximum Charge Size

(kg)

Retail food refrigeration Convenience Store 30 60 Direct rack / 4 compressor 300 400 Indirect rack / 4 compressor 150 250 Remote condensing unit / air

- cooled 5 hp unit 10 12 Remote condensing unit / air

- cooled 10 hp unit 36 47 Stand

- alone self

- contained display case 0.9 1.2 Vending machines Vending machines 0.5 2 Commercial ice machines Commercial ice machines 10 50 Bolded applications represent those modeled in this risk screen. To represent a reasonable worst

- case scenario for the retail food refrigeration end

- use, it is assumed that a catastrophic leak of refrigerant occurs while a direct rack system and a stand

- alone beverage cooler are installed at the end

- use (i.e., a grocery supermarket a nd a convenience store, respectively). The analysis considers the typical charge size provided by the submitter for each scenario. Because retail refrigeration equipment can be installed in a wide range of locations with varying room volumes, the analysis in this risk screen conservatively assumes that the direct rack system is located in a grocery supermarket and the beverage cooler is located in a convenience store. The grocery supermarket is assumed to have an effective volume of 24,200 m 3 (855,000 ft 3 ) with an effective floor area of 4,400 m 2 (i.e., excluding the space filled by the rack system, shelving, display cases, etc.) and a height of 5.5 meters (Armines 2008). The convenience store is assumed to have an effective volume of 244 m 3 (8,620 ft 3 ) with an effective floor area of 102 m 2 (i.e., excluding the space filled by the beverage cooler, shelving, display cases, etc.) and a height of 2.4 meters. For the vending machine end

- use, it is assumed that the vending machine is located in the minimum room size, an enclosed alcove of a commercial building that can be isolated by a door. The alcove is assumed to have an effective floor area of 6.15 m 2 (i.e., excluding the space filled by the vending machine, furniture, boxes, etc.) and a height of 2.4 meters, equivalent to a volume of 15 m 3 (530 ft 3 ).
For the commercial ice machines end

- use, it is assumed that the ice machine is also located in a convenience store with an assumed effective volume of 244 m 3 (8,620 ft 3 ), with an effective floor area of 102 m 2 ( i.e., excluding the space filled by the beverage cooler, shelving, display cases, etc.) and a height of 2.4 meters). Under these worst

- case scenarios, the full charge of each unit is assumed to be emitted over the course of one minute, into the grocery sup ermarket, convenience store, or enclosed alcove with 8, 1, and 0.5 air changes per hour (ACH), respectively 4 over the course of two time durations: 1) one minute, which represents a catastrophic release of refrigerant due to a puncture or other major damag e to the refrigeration system, and 2) fifteen minutes, which represents the accidental release of refrigerant due to a non

catastrophic leak in the system (e.g., valve failure). The one

- minute time duration is most appropriate for flammable refrigerants an d presents a less relevant scenario for R

- 450A, which is nonflammable. Therefore, while both scenarios are evaluated in this risk screen for consistency purposes, the scenario which analyzes a release of refrigerant over a 15

- minute time duration more accu rately represents a reasonable worst

- case scenario for R

- 450A in retail food refrigeration, vending machines, and commercial ice machines.

4 The air exchange rate is derived from the requirements in ANSI/ASHRAE Standard 62.1

- 2007, Table 6.1 (ANSI/ASHRAE 200 7). Ventilation requirements (presented as cubic feet per minute per square foot of ventilated space in the standard) were converted to air exchanges per hour using the assumed room size for the scenario.Final

-- October 10 , 2014 8 A vertical concentration gradient is also assumed since R

- 450A is denser than air (the specific gravities of both HF C

- 134a and HFO

- 1234ze(E) are greater than 1) and will settle in higher concentrations closer to the ground. In order to simulate the vertical concentration gradient, it is assumed that 95 percent of the leaked refrigerant mixes evenly into the bottom 0.4 meter of the room, and the rest of the refrigerant mixes evenly in the remaining volume (Kataoka 2000). Table 4 details the end

- use modeling assumptions used throughout the risk screen (i.e., in Sections 8, 9 and 10). Table 4. End

- Use Scenario Model Assump tions Parameter Assumptions (Large Retail Food) Assumptions (Small

Retail Food) Assumptions

(Vending Machine) Assumptions (Ice Machine)
Refrigeration Unit Direct Rack System Stand

- Alone Beverage

Cooler Vending Machine Ice Machine Room Grocery Supermarket Convenience Store Enclosed Alcove Kitchen of Small Fast Food Restaurant Charge Size (kg) 300; 400 0.9; 1.2 0.5; 2 10; 50 Length of Release (minutes) 1 ; 15 1; 15 1; 15 1; 15 Room Size (volume

- m 3 ) 24,200 a 244 b 15 244 b Room Ventilation (air changes per hour) 8 1 0.5 1 Vertical Concentration Gradient Yes Yes Yes Yes

a The average grocery supermarket sales area size found during a California survey (Armines 2008)

– 4,400 m 2

– was used for this scenario and a 5.5 m (18

- foot) ceiling was assumed. b Specific information was not available regarding which types of stores would utilize beverage cases or commercial ice machine s, so a small store (i.e., a convenience store) was used in the model. The minimum convenience store size found during a California survey (Armines 2008)

– 100 m 2

– was used for this scenario and an 8

- foot ceiling was assumed.
EPA recognizes that direct rack systems, beverage coolers, other retail food refrig eration units, vending machines, and commercial ice machines may be placed in a variety of stores, establishments, and rooms with different sizes and ventilation rates. When units are installed in smaller, enclosed spaces, there is a higher risk for asphyx iation or exposure concerns. To address this variability in room volumes and charge sizes for installed retail food equipment, vending machines, and commercial ice machines, this risk screen incorporates threshold analyses in addition to the worst

- case sce nario modeling. The threshold analyses are performed in order to determine the room size and charge size requirements that ensure that the use of R

450A in retail food refrigeration, vending machines, and commercial ice machines does not present risk to
en d

- users or servicing technicians.



### 6. POTENTIAL HEALTH EFFECTS To assess potential health risks from exposure to the proposed substitute in retail food refrigeration, vending machines, and commercial ice machines, EPA identified the relevant toxicity thresh old values for comparison to modeled exposure concentrations for different scenarios. In March 2014, R

- 450A was submitted to ASHRAE’s Standing Standard Project Committee (SSPC) for inclusion in ASHRAE Standard 34 under safety group A1 with a RCL of 72,000 ppm. 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 refrige ration 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

- 450A in addition to the lower flammability limit, hypoxia no observed adverseFinal

-- October 10 , 2014 9 effect level (NOAEL), and exposure limits, as an additional, conservative limit to ensure that significant flammabi lity, asphyxiation, and end

- use exposure 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 expo sure limits. Potential risks of chronic worker exposure were evaluated using workplace guidance levels (WGLs). Risks from potential short

- term consumer exposures were evaluated by comparing exposure concentrations to emergency guidance levels (EGLs). In the absence of an established short

- term exposure limit (STEL), acute exposure guideline level (AEGL), or emergency response planning guideline (ERPG) for R

- 450A, potential short

term, end

- use exposures were evaluated on a component basis (i.e., HFC

- 134a a nd HFO

- 1234ze(E)). Table 5 lists the relevant toxicity limits for R

- 450A and its components and is followed by Table 6, which provides an explanation of each toxicity limit. EPA’s approach for identifying or developing these values is discussed in Chapte r 3 of the Background Document.
Table 5. Exposure Limits of R

- 450A Components
R
- 450A Component WGL

(Long

- term Exposure) ppm EGL

(Short

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

- 450A 880 (8

- hour AEL) 2,640 (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

- 1234ze(E) 800 (8

- hour WEEL) 2,400 (15

- min STEL) b NA c NA = Not available

a Neither ACGIH nor AIHA recommend ceiling or short term exposure limits for the blend R

- 450A. A STEL for R

- 450A of 2,640 ppm was developed by EPA based on the 880 ppm 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 = 880 ppm x 3 ≈ 2,640 ppm b Neither ACGIH nor AIHA recommend ceiling or short term exposure limits for HFO

- 1234ze(E). A STEL for HFO

- 1234ze(E) of 2,400 ppm was developed by EPA based on the 800 ppm WEEL value. The STEL was estimated as three to five times the AEL, which is an establi shed method of estimating a short

- term exposure limit by ACGIH . [STEL] = [AEL] x 3 = 800 ppm x 3 ≈ 2,400 ppm

c Although a RCL has not been proposed for HFO

- 1234ze(E), t he recommended ATEL for HFO

- 1234ze(E) is 59,000 ppm (Honeywell 2014a).

Table 6. Explanat ion of Exposure Limit

- Related Terminology a 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). Determi nation 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 t he refrigerant concentration limit intended to r educe 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 nerv ous systemFinal

-- October 10 , 2014 10 effects and other escape i mpairing 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) expos ure that should not be exceeded during a workday, even if the 8

- hour TWA is within the TLV

– TWA, set by ACGIH.

AEGL b,c Acute Exposure Guideline

Level 1 AEGL

- 1 is the airborne concentration of a substance above which it is predicted that the general popula tion, 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 adver se 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 time

- weighted average exposure limit set by OSHA. AEL Acceptable Exposure Limit The maximum 8

- hour time weighted average (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 dail y exposures over a working lifetime and averaged over an 8

- hour workday. TLV

- TWA Threshold Limit Value

– Time

Weighted Average The 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 A pplicable to emergency exposure periods ranging from 10 minutes to 8 hours. According to the MSDS, exposure to R

- 450A may be hazardous if inhalation, skin contact, or eye contact with R

- 450A occurs. The most likely pathway of exposure is through inhalation. R

- 450A can cause symptoms of asphyxia tion 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. Unde r some circumstances of over

exposure (i.e., oxygen levels fall below 6 percent by volume), death may occur.
If R

- 450A is inhaled, person(s) should be immediately removed and exposed to fresh air. In accordance with the MSDS, EPA further recommends that i f breathing is difficult or irregular, person(s) be given oxygen, provided a qualified operator is present, and medical attention be sought. Rescuers should not attempt to retrieve victims of exposure to R

- 450A without adequate PPE. At a minimum, a self

- co ntained breathing apparatus (SCBA) should be worn. Exposures of R

- 450A to the skin may cause frostbite. In the case of dermal exposure, the MSDS for R

- 450A 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

- 450A to the eyes could cause eye irritation. In case of ocular exposure, the MSDS for R

- 450A recommends that person(s) immediately flush the eyes, including under the eyelids, with copious amounts of water for 15 minutes.Final

-- October 10 , 2014 11 EPA’s review of the human health impacts of this proposed sub stitute is contained in the public docket for this decision. These risks and procedures after exposure are similar for other common refrigerants. The potential health effects of R

- 450A can be minimized by following the exposure guidelines and ventilation
a nd PPE recommendations outlined in the MSDS for R

- 450A and this risk screen.



### 7. FLAMMABILITY ASSESSMENT
R

- 450A has been submitted to the ASHRAE SSPC 34 committee for classification as an A1 refrigerant, and is considered to be nonflammable (Honeywell 2014). Based on this classification, manufacture, servicing, and use of R

- 450A is not expected to present a flammability risk in the retail food refrigeration, vending machines, or commercial ice machine end

- uses.


### 8. ASPHYXIATION ASSESSMENT
The risk of as phyxiation for the reasonable worst

- case scenario was investigated for R

- 450A. In this section, risk of asphyxiation is assessed in three ways: 1) modeling the oxygen concentration under the charge size and room size specified in the worst

- case scenario, 2 ) performing a threshold analysis of minimum charge size needed to cause an asphyxiation risk in the room size specified in the worst

- case scenario 3) performing a threshold analysis of the maximum room size needed to cause an asphyxiation risk with the ch arge size specified in the worst

- case scenario. This analysis does not consider ventilation or conditions that are likely to occur that would increase oxygen levels to which individuals would be exposed, such as open doors or windows, fans operating, cond itioned airflow (either heated or cooled), or even openings at the bottom of doors that allow air to flow in and out. As specified in Section 5, the reasonable worst

- case scenario assumes a vertical concentration gradient. If the proposed substitute passes the screening analysis with these restrictive assumptions in place, it can be reasonably assumed that no risks of asphyxiation will be present under real

- world conditions. The results of the asphyxiation assessment are summarized in Table 7 below.
Table 7. Asphyxiation Assessment a,b
Equipment Scenario Charge Size (kg) Effective Room Size

(m 3 ) Percent Oxygen

Concentration in Lower 0.4 Meters Direct Rack System Reasonable Worst

- Case 1 300 24,200 (855,000 ft 3 ) 20 % Beverage Cooler Reasonable Worst

- Case 2 0.9 244 (8,620 ft 3 ) 21% Vending Machine Reasonable Worst

- Case 3 0.5 15 (530 ft 3 ) 20 %
Ice Machine Reasonable Worst

- Case 4 10 50 (1,770 ft 3 ) 20 % Direct Rack System Threshold Analysis 1a: Charge Size 1,360 24,200 (855,000 ft 3 ) 12%

Threshold Analysis 1b: Room Size 300 5,330 (18,800 ft3) 12% Beverage Cooler Threshold Analysis 2a: Charge Size 30.9 244 (8,620 ft 3 ) 12%

Threshold Analysis 2b: Room Size 0.9 7 (250 ft 3 ) 12% Vending Machine Threshold Analysis 3a: Charge Size 1.9 15 (530 ft 3 ) 12%

Threshold Analysis 3b: Room Size 0.5 4 (140 ft 3 ) 12%
Ice Machine Threshold Analysis 4a: Charge Size 31 50 (1770 ft 3 ) 12%

Threshold Analysis 4b: Room Size 10 79 (2,790 ft 3 ) 12% Bold font indicates modeling results.

a Cells highlighted in green are the scenarios in which the charge and room sizes evaluated in this risk screen are acceptable according to the threshold analysis or the scenarios with acceptable oxygen concentrations, given various modeling assumption opt ions. b The typical concentration of oxygen in air is considered to be 21 percent (Mackenzie & Mackenzie 1995).Final

-- October 10 , 2014 12 Based on the worst

- case scenario modeling assumptions, R

- 450A in retail food refrigeration, vending machines, and commercial ice machines does not present a significant risk of asphyxiation. In order for a risk of asphyxiation to occur, the normal concentr ation of oxygen in air (21 percent) in the lower 0.4 meters of the room must be reduced to 12 percent. 5 Based on the reasonable worst

- case scenario modeling assumptions, use of R

- 450A in retail food refrigeration equipment, vending machines, and commercial ice machines does not present a significant risk of asphyxiation:

 As shown in Threshold Analysis 1a for direct rack systems, the minimum charge size of R

- 450A necessary to reduce the oxygen levels to 12 percent in air in the lower 0.4 meters of a room of volume 24,200 m 3 (855,000 ft 3 ) was calculated to be 1,360 kg assuming that 1) nitrogen and oxygen retain the same relative volumes in the rooms with the balance composed entirely of R

450A, and 2) the pressure of the room does not increase significantly wi th the addition of the refrigerant. This amount represents almost five times the typical charge of approximately 300 kg (or more than three times the maximum charge size of 400 kg) for a direct rack R

- 450A system.

 Under Threshold Analysis 2a for beverage coolers, the minimum charge of R

- 450A necessary to reduce the oxygen levels to 12 percent in air in the lower 0.4 meters of a room of volume 244 m 3 (8,620 ft 3 ) was calculated to be 30.9 kg, which represents almost 35 times the typical charge of 0.9 kg for a single R

- 450A beverage cooler (or 25 times the maximum intended charge size of 1.2 kg).

 For vending machines, Threshold Analysis 3a shows that under similar assumptions, the minimum charge of R

- 450A necessary to reduce oxygen levels to 12% in air in the lower 0.4 meters of a room of volume 15m 3 (530 ft 3 ) was calculated to be 1.9 kg, almost four times the typical charge of approximately 0.5 kg for a vending machine. The maximum charge size intended for R

- 450A vending machines of 2 kg, does exceed the maxi mum charge size for which an asphyxiation risk could occur in the specified area (i.e., 15 m 3 ) under the assumptions specified in Section 5.

 For commercial ice machines, Threshold Analysis 4a shows that the minimum charge of R

- 450A necessary to reduce oxy gen levels to 12% in air in the lower 0.4 meters of a room of volume 244

m 3 (8,620 ft 3 ) was calculated to be 31 kg, more than three times the typical charge of approximately 10 kg for a commercial ice machine. The maximum charge size intended for R

450A co mmercial ice machine of 50 kg, does exceed the maximum charge size for which an asphyxiation risk could occur in the specified area (i.e., 244 m 3 ) under the assumptions specified in Section 5. Because this threshold modeling does not take into account any ventilation which is likely to occur, such as conditioned airflow, open doors, or even openings at the bottom of doors that allow air to flow in and out, as mentioned above, the actual asphyxiation risk to consumers is likely to be smaller than modeled. For the room size Threshold Scenarios, the room size at which an asphyxiation concern would exist (i.e., when the oxygen concentration in the lower 0.4 meters of the room is 12 percent) using the typical equipment charge sizes provided by the submitter wer e also determined:

 For direct rack systems, in order for asphyxiation to be of concern with a charge size of 300 kg, the system would have to be installed in a store with an effective volume of 5,330 m 3 (18,800 ft 3 ) (see Threshold Analysis 1b in Table 7).

 For beverage coolers, in order for asphyxiation to be of concern with the typical charge size of 0.9 kg, the volume of the food preparation area would have to be about 7 m 3 (250 ft 3 ) (see Threshold Analysis 2b in Table 7).

 For vending machines, Thresho ld Analysis 3b indicates that the volume of the vending machine area would have to be about 4 m 3 (140 ft 3 ) with the typical charge size of 0.5 kg in order for asphyxiation to be a concern.

7 Twelve percent oxygen in air is the No Observed Adverse Effect Level (NOAEL) for hypoxia (ICF 1997).Final

-- October 10 , 2014 13  For commercial ice machines, Threshold Analysis 4b indicates that the volume of the commercial ice machine area would have to be about 79 m 3 (2,790 ft 3 ) with the typical charge size of 10 kg in order for asphyxiation to be a concern. Based on the worst

- case modeling results and threshold analysis, EPA does not believe t hat the use of R

450A in retail food refrigeration, vending machines, and commercial ice machines poses a significant risk of asphyxiation or impaired coordination to personnel, provided systems are installed in appropriate spaces according to guidelines f

rom the manufacturer and the MSDS for R

- 450A.



### 9. END

- USE EXPOSURE ASSESSMENT This section presents estimates of potential end

- user exposures to R

- 450A and each of its chemical constituents in the event of a catastrophic release from the proposed substitute’s use in retail food refrigeration, vending machines, and commercial ice machines. An end

- use exposure analysis was performed to examine potential catastrophic releases of R

- 450A under the reasonable worst

- case scenarios outlined in Section 5.
F or the end

- use exposure assessment scenario, 15

- minute TWA exposures for the proposed substitute were calculated using the box model described in the Background Document, which was adapted to estimate concentrations on a minute

- by

- minute basis. Estimates f or acute/short

- term end

- use exposures resulting from catastrophic leakage of refrigerant from retail food refrigeration, vending machines, and commercial ice machines were examined. The analysis was undertaken to determine the 15

- minute exposures for R

450 A, which were then compared to the standard toxicity limits presented in Table 5 to assess the risk to end

- users. Because HFO

- 1234ze(E) is present in larger concentrations and because it has a lower exposure limit than HFC

- 134a, Table 8 displays only HFO

- 1 234ze(E), the component with greater potential

concerns

. The estimated TWA values are fairly conservative as the analysis does not consider opened windows, fans operating, conditioned airflow (either heated or cooled) and other variables that would reduce the levels to which individuals would be exposed.

Table 8. End

- Use Exposure Assessment for HFO

- 1234ze(E) Component a ,b
Equipment Scenario Charge Size (kg) Room

Size (m 3 ) Length of

Release (min) 15
- min TWA End
- Use

Exposure (ppm)
Direct Rack System Reasonable Worst

- Case Scenario 1a 300 24,400 1 18,600

Reasonable Worst

- Case Scenario 1 b 15 10,100 Beverage Cooler Reasonable Worst

- Case Scenario 2a 0.9 244 1 2,460

Reasonable Worst

- Case Scenario 2b 15 1,340 Vending Machine Reasonable Worst

- Case Scenario 3a 0.5 15 1 22,200

Reasonable Worst

- Case Scenario 3b 15 12,100

Ice Machine Reasonable Worst

- Case Scenario 4a 10 244 1 27,400

Reasonable Worst

- Case Scenario 4b 15 14,900 Bold font indicates modeling results.

a Cells highlighted in green are the scenarios with acceptable exposure levels given various modeling assumption options. b 15

- min STEL for HFO

- 1234ze(E) is 2,400 ppm and ATEL for HFO

- 1234ze(E) is 59,000 ppm; see Table 4 for more information.
Under the reasonable worst

- case scenarios described in Section 5 for direct rack systems , beverage coolers , vending machines, and ice machines catastrophic releases of the typical charge sizes of R

- 450A were modeled. The modeling scenarios evaluate two refrigerant r elease time durations (i.e., 1 minute and 15 minutes). The anticipated 15

- minute TWA exposures for the HFO

- 1234ze(E) component of R

- 450A are likely to exceed its STEL (i.e., 2,400 ppm) for all scenarios except Reasonable Worst

- Case Scenario 2b, which assum es a 15

- minute release for a beverage cooler in a convenience store. Although most of the exposure estimates for the reasonable worst

- case scenarios exceed the STEL (i.e., 2,400 ppm) (see TableFinal

-- October 10 , 2014 14 8), the STEL is a conservatively

- derived exposure limit that i s intended to protect against risk with a wide safety margin for even the most sensitive of populations. All of these exposure estimates are significantly lower than the acute toxicity exposure limit (ATEL) of 59,000 ppm for HFO

- 1234ze(E), which is a refri gerant concentration limit intended to reduce the risks of acute toxicity hazards in normally occupied, enclosed spaces according to ASHRAE Standard 34. Furthermore, the estimated exposures for R

- 450A in each of these scenarios are also significantly lower than the RCL for R

- 450A (i.e., 72,000 ppm).
In addition, t hese exposure estimates were derived using fairly conservative assumptions (e.g., minimum room volume, low ventilation rate, maximum charge size) that do not necessarily reflect the actual room attributes where R

- 450A retail food refrigeration equipment, vending machines, and commercial ice machines will be installed. Finally, these exposures represent concentrations of leaked refrigerant in the bottom 0.4 meter (1.3 feet) of the room , accounting for 95 percent of the refrigerant charge in this lower compartment of the room. The probability that an individual would be present in this lower compartment (e.g., prone or supine on the floor) in the event of the catastrophic release of refrigerant is l ow. To prevent exposure and potential serious side effects during larger releases, EPA recommends that the proposed RCL for R

- 450A (i.e., 72,000 ppm or 320 g/m 3 ) is not exceeded in any location where an R

450A system is installed, unless proper leak protection devices are in place in order to prevent exposures of R

- 450A beyond the recommended limits. Proper leak protection devices , engineering control requirements, and adherence to the MSDS will further ensure that exposure limits are maintained below those described in Table 8.



### 10. OCCUPATIONAL EXPOSURE ASSESSMENT This section assesses potential exposures to workers during manufacture, charging and servicing, and disposal of R

- 450A retail food refrigeration equipment, vending machines, and commercia l ice machines. To ensure that use of the proposed substitute in retail food refrigeration, vending machines, and commercial ice machines does not pose an unacceptable risk to workers during servicing and disposal, occupational exposure modeling was perfo rmed using a box

- model approach. For a detailed description of t he methodology used for this screening assessment, the reader is referred to the occupational exposure and hazard analysis described in Chapter 5 of the Background Document. Estimates of ref

rigerant release per event for various release scenarios were obtained from the Vintaging Model. 6 To determine the estimated level of occupational exposure for a constituent in a blend, the total anticipated release rate of the refrigerant is multiplied b y the weight percent composition of each compound in the blend; however, only the exposure concentrations for the HFO

- 1234ze(E) component are shown. For the retail food refrigeration and vending machine end

- uses, the release per event was conservatively as sumed to range between 0.25 percent and 5 percent of the equipment charge during charging and servicing (see Section 10.2) and 13.5 to 81 percent of the equipment charge during disposal (see Section 10.3). The release rate per event was multiplied by the n umber of events estimated to occur over a workday. For equipment charging and servicing, the number of events per workday was assumed to equal the maximum number of units anticipated to be serviced in one day (i.e., eight units divided by eight hours per workday for beverage coolers, vending machines, and commercial ice machines, and one unit divided by eight hours per workday for direct rack systems). For disposal, i t was conservatively assumed that 10 units are disposed during an 8

- hour work day for sma ller equipment and one unit per day for direct rack systems. The modeled exposure concentrations were compared to short

- term occupational exposure limits at installation and servicing and long

- term exposure limits at disposal.

6 ICF International maintains the Vintaging Model for EPA in order to simulate the aggregate impacts of the ODS phaseout on the use and emissions of various ODS and their substitutes over a period of sev eral years across 60 different end

- uses. The model tracks the use and emissions of various compounds for the annual vintages of new equipment that enter service in each end

- use. The vintage of each type of equipment determines such factors as leak rate, charge size, number of units in operation, and the initial ODS substance that the equipment contained.Final

-- October 10 , 2014 15 10.1 Occupational Exposure at Manufacture

HFC

- 134a is obtained by the submitter from other manufacturers and HFO

- 1234ze(E) is manufactured by the submitter in the United States. During manufacture of the components and blending of R

- 450A, the MSDS for both HFC

- 134a and HFO

- 1234ze(E) should be referenced and proper engineering controls and PPE used.

R

- 450A and its components are not expected to pose a risk to workers during manufacture or blending when the engineering controls and PPE recommendations referenced in the MSDS for HFC

- 1 34a, HFO

1234ze(E), and R

- 450A are followed. Release points/exposure in chemical manufacturing would typically be where temporary lines are connected or disconnected (i.e., filling of portable cylinders and portable bulk containers). Refrigerant quality co ntrol testing may result in release of de minimus quantities of refrigerant, which would typically be to exhaust ducts or fume hoods. Engineering controls should include normal and local ventilation (e.g., chemical hoods) and vapor

- in

- air detection and ala rm systems for standard manufacturing procedures so workers can avoid physical contact with the refrigerant and to achieve emission control. In general, use of PPE consistent with OSHA guidelines is recommended, such as respiratory protection (including a SCBA in case of insufficient ventilation), tightly sealed 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 HFC

- 134a or HFO

- 1234ze(E) 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

- s ealed 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 and manu facturing practices and the MSDS for R

- 450A and its components, there is no significant risk to workers during the manufacture of R

- 450A.

10.2 Occupational Exposure at Charging and Servicing As indicated by the submitter, large commercial refrigeration equ ipment (e.g., direct rack systems) is typically field

- erected and therefore equipment is charged in the field. Smaller retail refrigeration equipment (e.g, beverage coolers), vending machines, and commercial ice machines would occur by the Original Equipme nt Manufacturer (OEM). For both OEM system manufacture (i.e., charging at OEM location) and field charging (i.e., charging at the end

- use location), points of release for charging and servicing these leak

- tight systems would be from connection/disconnectio n of temporary lines for charging and recovery equipment. Charging occurs within an enclosed area equipped with automatic ventilation, refrigerant detectors, and alarm systems. The submitter indicated that charging equipment is operated only by trained tec hnicians. 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 release s (Honeywell 2014). During servicing, used refrigerant from R

- 450A retail food refrigeration equipment, vending machines, and commercial ice machines is pumped into a canister, where it is stored until it is recycled (i.e., filtered and reused). During the transfer to the initial canister, incidental refrigerant releases may occur during connection and disconnection of the recharging hose fittings (Honeywell 2014). Isolation and evacuation of lines or equipment prior to servicing or repair and the use of co mpatible seals, gaskets, O

- rings, thread sealants, and minimization of threaded joints all contribute to limiting releases. Room ventilation, leak monitors, and alarms also help minimize exposure.Final

-- October 10 , 2014 16 Charging and servicing activities for retail refrigeration equipment, vending machines, and commercial ice machines are not expected to result in significant worker exposure when certified technicians follow the procedures outlined in the R

- 450A MSDS and maintenance manual, undergo proper training, and wear appro priate PPE (e.g., gloves and safety glasses). Nevertheless, the potential occupational exposure during servicing was analyzed. The maximum 15

- minute time weighted average (TWA) exposures for each R

450A constituent were estimated for the servicing exposure scenario and compared to their respective short

- term exposure limits (see Table 9). Because HFO

- 1234ze(E) is present in larger concentrations and because it has a lower exposure limit than HFC

- 134a, Table 9 displays results only for HFO

- 1234ze(E), the component with greater potential concerns. Table 9. Occupational Risk Assessment at Charging and Servicing for HFO

- 1234ze(E) Component a

Equipment Charging Servicing 15
- min Short Term Exposure Limits (ppm) Release Rate b 15
- minute

TWA (ppm) Release Rate b 15
- minute TWA (ppm) Direct Rack System c 2% 440 5% 1,100 2,400 d Beverage Cooler 1% 5 0.25% 1.3 Vending Machine 1% 3 0.25% 0.74 Ice Machine 1% 59 3% 180 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) and CARB (2013)

c One installation or servicing event per day was modeled for direct rack systems d EPA

- derived STEL (see Table 4)

The 15

- mi n STEL for HFO

- 1234ze(E) is not exceeded in the charging or servicing exposure scenarios for all four equipment types. In addition, t he estimated exposures were derived using conservative assumptions, and do not take into account the use of ventilation or PPE. These types of systems are typically serviced by Section 608

- certified personnel using proper industrial hygiene techniques and using proper engineering controls (e.g., local ventilation, refrigerant detectors, and alarm systems). Thus, EPA does not b elieve that charging, installation, or servicing of retail food refrigeration units, vending machines, and commercial ice machines containing R

- 450A presents a significant concern to workers.

10.3 Occupational Exposure at Disposal Disposal of R

- 450A retai l food refrigeration equipment is expected to occur with limited frequency (up to approximately ten disposal events per day for smaller equipment such as beverage coolers, vending machines, and commercial ice machines and one disposal event per day for dir ect rack systems) at disposal facilities or, for larger equipment (e.g., direct rack systems) at the end

- use and with limited duration of exposure to the installed refrigerant. Typically, potential exposures to the refrigerant during recovery and disposal are expected to occur during activities related to decommissioning refrigeration systems (e.g., attaching of hoses associated with draining or otherwise discharging of refrigerant from the refrigeration units into cylinders) and would be similar to those d uring servicing, 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, exposur es during servicing (and therefore during typical disposal activities) are not anticipated to present a significant concern for workers. To model a worst

- case scenario during disposal, scenarios were modeled in which the portion of refrigerant that is not recovered during decommissioning of equipment (e.g., due to technical efficiency of recovery equipment) is released during the recovery process in the presence of workers. The implied maximum release rates workers could be exposed to under the reasonable w orst

- case disposal scenario are shown in Table 10.Final

-- October 10 , 2014 17 Table 10. Assumed Release Rates during Disposal
Equipment Percent Remaining at Disposal Recovery

Efficiency Implied Maximum

Disposal Release Rate Direct Rack System 90% 85% 14% Beverage Cooler 90% 10% 81% Vending Machine 90% 10% 81% Ice Machine 80% 70% 24% Source: Release rate assumptions consistent with IPCC (2006), UK DECC (2011) and CARB (2013) Because HFO

- 1234ze(E) is present in larger concentrations and because it has a lower exposure limit than HFC

- 134a, Table 11 displays the maximum estimated 8

- hour TWA occupational exposure levels for only HFO

- 1234ze(E) disposal, , the component with greater potential concerns. Based on the assumptions described in the beginning of Section 10, the modeling indicates the following:

 The 8

- hour worker exposure concentrations for the HFO

- 1234ze(E) component will at no point exceed the long

- term exposure limit (i.e., 800 ppm) during disposal of R

- 450A for beverage coolers and vending machines during the 81 perce nt release scenarios.

 Under the disposal release scenarios for the direct rack system and commercial ice machines, the modeling indicates that occupational exposure could exceed the 8

- hour long term exposure limit for HFO

- 1234ze(E).

Table 11. Occupati onal Risk Assessment at Disposal for HFO

- 1234ze(E) Component a
Equipment Percent Release 8
- Hour TWA Occupational Exposure (ppm) 8
- Hour Long Term

Exposure Limits (ppm) Direct Rack System 14% 3,200
800 b Beverage Cooler 81% 570 Vending Machine 81% 320 Ice Machine 24% 1,900 Bold font indicates modeling results.

a Cells highlighted in green are the scenarios with exposure levels deemed to be acceptable given various modeling assumption o ptions. b WEEL OEL Although the modeling indicates that the worse

- case disposal scenario for direct rack systems and commercial ice machines could exceed the WE EL for HFO

- 1234ze(E), the estimated exposures were derived using conservative assumptions (e.g., no mechanical or l ocal exhaust ventilation) , and represent a worst

- case scenario with a low probability of occurrence (e.g., for smaller commercial refrigeration equipment, it is highly unlikely that a worker would be exposed to the maximum release rate at disposal for ever y unit decommissioned in a day). These types of systems are also typically disposed of by Section 608

- certified personnel using proper industrial hygiene techniques to maximize recover y efficiency and limit releases. The average recovery efficiencies and maximum disposal release rates (see Table 10) are also representative of release rates for currently used refrigerants in commercial refrigeration equipment (e.g., HFC

- 134a, R

- 404A), and there are already established standards of practice and training requ irements that apply to fluorinated refrigerants to reduce exposures (and would therefore extend to R

450A systems ).

It is also unlikely that workers would be exposed to the unrecoverable portion of refrigerant during the recovery process , and therefore a nticipated exposures would be much lower . For example, some of the refrigerant would likely be dissolved in the refrigerant oil (which would be drawn out and separated from the recovered refrigerant) or trapped within deeper parts of the refrigeration circ uit (e.g., the accumulatorFinal

-- October 10 , 2014 18 or receiver) and wouldn’t be released until the system is actually dismantled later on in the disposal process (Oko

- Recherche 2003).
Because anticipated occupational exposures could be above the exposure limits for HFO

- 1234ze(E) for the direct rack system and commercial ice machine disposal release scenarios, the recommendations for proper engineering controls and PPE in the MSDS for R

- 450A should be followed. Adequate ventilation should always be established during any use, handling, or storage of R

- 450A

. If recovery and 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 SCBA and other appropriate prot ective equipment

. Engineering controls should include vapor

- in air detection systems and local exhaust ventilation during use of R

- 450A to prevent dispersion throughout the workplace. In addition, an eye wash and safety shower should be near the manufact uring facility and locations where R

- 450A is stored and ready for use. In general, use of PPE is recommended, such as splash goggles, mechanical

- resistance gloves (e.g., oil

repellent or thermal resistant gloves) when handling cylinders and chemically

- resi stant gloves when handling the gas mixture (e.g., butyl rubber, chlorinated polyethylene, or neoprene). For larger retail food refrigeration ( e.g. , rack systems) and commercial ice machine (e.g., remote systems) systems, toxicity risks could be further min imized through t he installation of signage which warns room occupants to remain standing (as higher concentrations are likely to accumulate near the floor) and not to enter recessed parts of the facility (e.g., maintenance crawl spaces and below grade serv ice areas) and exit the facility immediately should they hear the refrigerant detector alarm and/or smell the leaked refrigerant . EPA believes that if proper handling and disposal guidelines are followed in accordance with good industrial hygiene and manufacturing practices and the MSDS for R

- 450A, there is no significant risk to workers during the manufacturing, installation, servicing, and disposal of R

- 450A in retail food refrigeration units, commercial ice machines, and vending machines.



### 11. GENERA L POPULATION EXPOSURE ASSESSMENT
R

- 450A 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 retail food refrigeration, vending machines, and commercial ice machines. T he 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

450A is a gas and, therefore, releases to ground or surface water are not anti cipated, as R

- 450A 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

- 450A). Should air releases during m anufacturing operations occur, engineering controls should be used (e.g., carbon absorption scrubbers) to collect R

- 450A and prevent the release of R

- 450A to the atmosphere. EPA believes that by using proper engineering controls and by following disposal a nd containment recommendations outlined in the proposed substitute’s MSDS, exposure to R

- 450A is not expected to pose a significant toxicity risk to the general population.Final

-- October 10 , 2014 19 

### 12. REFERENCES Armines. 2008. Inventory of Direct and Indirect GHG Emissions from Stationary Air Conditioning and Refrigeration Sources, with Special Emphasis on Retail Food Refrigeration and Unit ary Air Conditioning. CARB Agreement No. 06

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. ACGIH. 2012. Guide to Occupational Exposure Values. Ameri can Conference of Governmental Industrial Hygienists.
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. ANSI/ASHRAE. 2013a. Standard 62: Ventilation for Acceptable Indoor Air Quality. American Society of Heating, Refrigerating and Air

- Conditioning Engineers, Inc. CARB. Gallagher, Glenn, Tao Zhan, Ying

- Kuang Hsu, et. al. 2013. “High

- global Warming Potential F

gas Emissions in California: Comparison of Ambient

- based versus Inventory

- based Emission Estimates, and Implications of Refined Es timates.” Environ. Sci. Technol., 2014, 48 (2), pp 1084

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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 Con stituents 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. Hodnebrog, Ø., Etminan, M., Fuglestvedt, J. S., Marston, G., Myhre, G., Nielsen, C. J., Shine, K. P., Wallington, T. J. 2013. Global Warming Potentials and Radiative Efficiencies of Halocarbons and Related Compounds: A Comprehensive Review, Reviews of Geophysics, 51 , 300

- 378, doi: 10.1002/rog.20013

. Honeywell, Inc. 2014. Solstice® N

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- 450A). Significant New Alternatives Policy Program Submission to the United States Environmental Protection Agency. May 2014. Honeywell, Inc. 2014b. Response to Incompleteness Letter for Solstice® N

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- 450A) Signi ficant New Alternatives Policy Program Submission to the United States Environmental Protection Agency. August 11, 2014.
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.
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- 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.Final

-- October 10 , 2014 20 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.ipcc

nggip.iges.or.

jp/public/2006gl/pdf/3_Volume3/V3_7_Ch7_ODS_Substitutes.pdf. Kataoka, O., M. Yoshizawa, & T. Hirakawa 2000. “Allowable Charge Limit of Flammable Refrigerants and Ventilation Requirements.” Daikin Industries. International Refrigeration and Air Conditi oning Conference. Paper 506. Available online at: http://docs.lib.purdue.edu/iracc/506

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

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Oko

- Recherche GmbH. 2003. Final Rep ort on Establishing the Leakage Rates of Mobile Air Conditioners. Prepared for the European Commission. Available at: http://ec.europa.eu/clima/policies/eccp/doc s/leakage_rates_final_report_en.pdf

.
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. 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

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gas

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. 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.

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

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