Final

-- October 10, 2014 1 

## Significant New Alternatives Policy Program Refrigeration and Air Conditioning Sector
Risk Screen on Substitutes in Cold Storage Warehouse s and Industrial Process Refrigeration
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 respo nse to a series of diplomatic and legislative efforts that have taken place over the past two decade s , including the Montreal Protocol and the Clean Air Act Amendments of 1990 (CAAA). The U.S. Environmental Protection Agency (EPA), as authorized by Sectio n 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 including : refrigeration and air conditioning, solvent cleaning, foam blowing, aerosols, fire suppression, adhesives, coatings and inks, and sterilization. The results of these risk screens are presen ted in a series of Background Documents that are available in EPA's docket. The purpose of this risk screen is to supplement EPA’s Background Document on the refrigeration and air conditioning sector (EPA 1994) (hereinafter referred to as the Background Document) . This risk screen eval uates the potential use of R

- 450 A as a substitute i n the cold storage warehouse s and industrial process refrigeration end

- use s

. Table 1 presents the composition of the proposed sub stitute.

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 % t rans - 1,3,3,3,

- Tetrafluoro

- 1

- propene ( HFO

- 1234ze (E)) CHFCHCF 3 29118

- 24

- 9 58 % 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 AssessmentFinal

-- October 10, 2014 2  S ection 5 : Potential Health Ef fects

 Section 6 : Flammability Assessment

 Section 7 : Occupational Exposure Assessment

 Section 8 : General Population Exposure Assessment

 Section 9 : References


### 2. SUMMARY OF RESULTS
R

- 450 A is recommended for SNAP approval in cold storage warehouse s and industrial process refrigeration

. E PA's risk screen indicates that the use of the proposed substitute will be less harmful to the atmosphere than the continued use of commonly used refrigerants such as CFC

- 12 , HCFC

- 22 , and R

- 507 A 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 51.100(s)) , so environmental impac t from the release of these substances is not a
concern

. It is expected that the material safety data sheet (MSDS) for R

- 450 A and good manufacturing practices will be adhered to

. Additionally, it is expected that the appropriate safety and personal protective equipment (PPE) (e.g., protective gloves, tightly sealed goggles, protective work clothing, and suitable respiratory protection in case of leakage or insufficient ventilation) consistent with Occupational Safety and Health Administration (OSHA) guidelines will be used during installation , servicing, and disposal of cold storage and industrial process refrigeration systems using R

- 450 A

. Because cold storage and industrial process refrigeration systems are to be installed in locations with adequate space and/or ventilation in accordance with EPA recommendations and the equipment maintenance manual s for R

450 A in each end

- use , significant toxicity risk to personnel is also unlikely. Additional safeguards , including specified refrigerant concentration limits (RCL) of R

- 450 A and its 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 Exposure at the end

- use is captured in the occupational exposure assessment , as consumer use of cold storage and industrial process refrigeration equipment is not anticipated

. I n addition, potential health risks from exposure to the proposed substitute is considered to be a larger concern for workers than asphyxiat ion , 4 due to the large spaces in which these sys tems are installed and serviced. Therefore, an as phyxiation assessment was not conducted.


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

450 A in cold storage warehouses and industrial process refrigeration . The ozone depletion potential ( ODP ) , global warming potential ( GWP ) , and atmospheric lifetime (ALT) of the proposed substitute are presented in Table 2

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

- uses, such as CFC

12 and HCFC

- 22

. In addition, R

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

- 134a, R

- 404 A, and R

- 507A . Thus, EP A believes that the use of R

- 450 A would

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 e stablishes a uniform system for assigning reference numbers, safety classifications, and refrigerant concentration limits to refrigerants. Safety classifications based on toxic ity and flammability data are included. 3 Ventilation for Acceptable Indoor Air Quality ASHRAE Standard 62 establishes minimum ventilation rates and other measures intended to provide indoor air quality that is acceptable to human occupants and that minimizes adverse health effects

. 4 The oxygen deprivation limit (ODL) for R

- 450A is 140,000 ppm per Standard 34

- 2010 (Honeywell 2014a). Exposure estimates remain significantly below this level (see Table 6 in Section 7).Final

-- October 10, 2014 3 result in substantially less harm to the climate and ozone layer than the continued use of ODS and commonly used refrigerants in cold storage warehouses and industrial process refrigeration systems

. Table 2 . Atmospheric Impacts of R

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

- 450A 0 60 1 NA c Individual Components HFC

- 134a 0 1,430 14 HFO

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

- 12 0.82 10,900 100 HCFC

- 22 0.13 1,810 12 HFC

- 134a 0 1,430 14 R

- 404A e 0 3,922 NA f R

- 507A g 0 3,985 NA h

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 10 days (IPCC 4 th Assessment Report [Forster et al. 2007], Hodnebrog, O. et al. [ 2013 ] ). d Hodnebrog, O. et al. ( 2013 )

e R

- 404A is a blend consisting of HFC

- 143a (52%), HFC

- 125 (44%) and HFC

- 134a (4%). f 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 t he ALT for HFC

- 134a is 14 years (IPCC 4 th Assessment Report [Forster et al. 2007]). g R

- 507A is a blend consisting of HFC

- 125 (50%) and HFC

- 143a (50%). h Atmospheric lifetimes are not given for blends, because the components s eparate in the atmosphere. The ALT for HFC

- 1 25 is 29 years and ALT for HFC

- 143a is 52 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 release of HFC

- 134a and HFO

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


### 5
. POTENTIAL HEALTH EFFECTS To assess potential health risks from exposure to the proposed substitute in cold storage warehouses and industrial process refrigeration , EPA identified the relevant toxicity threshold values for comparison to modeled exposure concentratio ns 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 refrigeration concentration limit (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 refrigeration unit (ASHRAE 2010b). ASHRAE Standard 15 implements the aforementioned standard, requiring that “the concentration of refrigerant in an enclosed space following a complete discharge of a high

- probability system shall not exceed the RCL” (ASHRAE 2010a). As such, this ris k screen references the proposed RCL for R

- 450 A in addition to the hypoxia no observed adverse effect level ( NOAEL ) and exposure limits, as an additional, conservative limit to ensure that significant exposure risks do not occur. For the occupational ex posure analysis, potential risks from chronic and acute worker exposure were evaluated by comparing exposure concentrations to available occupational exposure limits. Potential risks of chronic worker exposure were evaluated using workplace guidance levels (WGL). 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, acute worker exposures were evaluated on a component basis ( i.e., HFC

- 134a and HFO

- 1234ze (E) ). Table 3 lists the relevant toxicityFinal

-- October 10, 2014 4 limits for R

- 450A and its component s and is followed by Table 4 , which provides an explanation of each toxicity limit

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

Table 3
. Exposure Limits of R

- 450 A Components
R
- 450 A Component WGL

(Long
- term Exposure) ppm EGL

(Short
- term Exposure) p pm 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) 8,0 00 (30

- min AEGL

- 1) 50,000
HFO

- 1234ze (E) 800 ( 8

- hour WEEL ) 2,400 ( 15

- min STEL ) c NA d 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 Honeywell (2014a)

c 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 WE EL 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 = 800 ppm x 3 ≈ 2,400 ppm d Although an RCL has not been proposed for HFO

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

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

Table 4 . Explanation of Exposure Limit

- Related Terminology a Organization Definition OSHA Occupational Safety and Health Admin istration NIOSH National Institute for Occupational Safety and Health ACGIH American Conference of Governmental Industrial Hygienists AIHA American Industrial Hygiene Association OARS Occupational Alliance for Risk Science Exposure Limit Definition Explanation Short
- Term Exposure RCL Refrigerant Concentration

Limit The RCL for a refrigerant is intended to reduce the risks of acute toxicity, asphyxiation, and flammability hazards in normally occupied, enclosed spaces. The RCL for each refrigerant is the lowest of the Acute

- Toxicity Exposure Limit (ATEL), Oxygen Deprivation Limit (ODL), and Flammable Concentration Limit (FCL). Determination assumes full vaporization with no removal by ventilation, dissolution, reaction, or decomposition and complete m ixing 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 nervous system effects and other escape i mpairing effects and permanent injury. The ATEL is s imilar to the Immediately Dangerous to Life or Health (IDLH) concentrations set by NIOSH

. STEL Short

- Term Exposure Limit A 15

- minute time

- weighted average (TWA) exposure that should not be exceeded during a workday, even if the 8

- hour TWA is within the 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 population, including susceptible individuals, could experience notable discomfort, irritation, or certain asymptomaticFinal

-- October 10, 2014 5 nonsensory effects. However, the effects are not disabling and are transient and reversible upon cessation of exposure. Acute Exposure Guideline Level 2 AEGL

- 2 is the airborne concentration (expressed as ppm or mg/m3) of a substance above which it is predicted that the general population, including susceptible individuals, could experience irreversible or other serious, long

- lasting adverse health effects or an impaired ability to escape. Acute Exposure Guideline Level 3 AEGL

- 3 is the airborne concentration (expressed as ppm or mg/m3) of a substance above which it is predicted that the general population, including susceptible individuals, could experience life

- threatening health effects or death. Long
- Term Exposure PEL Permissible Exposure Limit This is an 8

- hour 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 daily 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

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

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

- 450 A can cause symptoms of asphyxiation when present in concentrations high enough to significantly lower oxygen concentrations below 19.5 percent by volume, such as headaches, ringing in ears, dizziness, drowsiness, nausea, vomiting, depression of all senses, and also unconsciousness. Under some circumstances of over

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

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

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

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

- 4 50 A to the skin may cause frostbite. In the case of dermal exposure, the MSDS for R

- 4 50 A 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 affecte d area wit h a clean, soft cloth , and seek medical attentio n immediately. Exposures of R

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

- 450 A recommends that person(s) immediately flush the eyes, including under the eyelids, wi th copious amounts of water for 15 minutes. EPA’s review of the human health impacts of this proposed substitute is contained in the public docket for this decision. These risks and procedures after exposure are similar for other common refrigerants

. The p otential health effects of R

- 450 A can be minimized by following the exposure guidelines and ventilation and PPE recommendation s outlined in the MSDS for R

- 450 A and this risk screen.Final

-- October 10, 2014 6 

### 6
. 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 a ). Based on this classification, manufacture, servicing, and use of R

- 450A is not expected to present a flammab ility risk in the cold storage warehouses and industrial process refrigeration end

- uses

. 

### 7
. OCCUPATIONAL EXPOSURE ASSESSMENT To ensure that use of the proposed substitute in cold storage warehouses and industrial process refrigeration does not pose an unacceptable risk to workers during installation, servicing , and disposal, occupational exposure modeling at installation was performed for the proposed substitute. All installation, maintenance, and disposal activities for R

- 450A cold sto rage and industrial refrigeration systems are anticipated to occur on

- site. Although modeling is only performed for installation, it is assumed that exposure during servicing and disposal would not exceed exposure during installation because similar refrig erant charging and/or recovery equipment would be used

. Furthermore, because it is likely that less refrigerant remains in the unit at disposal, it is assumed that installation of refrigeration units in cold storage warehouses or industrial process refrige ration systems wo uld require transfer of a greater amount of refrigerant, and thus result in greater worker exposure. Thus, occupational exposure was conservatively modeled based on installation. The submitter anticipates that R

- 450A in cold storage warehouse refrigeration will have a typical charge size of 3 00 kg and a maximum charge size of 410 k g . H owever , charge sizes in cold storage warehouses can vary greatly by the storage volume, the desired temperature for refrigeration, and refrigeration feed (i.e. d irect expansion , flooded , or liquid recirculation )

. According to the submitter, charge sizes in i ndustrial process refrigeration system can vary greatly by application, load, and refrigerant feed, ranging from a typical charge siz e of 500 kg to a maximum charge size of 12,000 kg. The anticipated maximum and typical charge sizes for the proposed applications are summarized in Table 5

. Table 5 . Typical and Maximum Charge Sizes for R

- 450A Cold Storage Warehouse s and Industrial Process Refrigeration Applications
End
- Use Typical Charge Size (kg) Maximum Charge Size (kg) Cold Storage Warehouses a 300 410 Industrial Process Refrigeration b 500 12,000

a Varies greatly by storage volume, temperature and system configuration. b Varies greatly by application, load, and refrigerant feed options

. Installation of cold storage and industrial process refrigeration systems is expected to occur with limited frequency (up to approximately one event per day) and with limit ed duration of exposure to the refrigerant charge. Release points during installation would be connection/disconnection of temporary lines from charging equipment. Refrigerant contained in temporary lines during charging would be recovered, and breaking of fittings should result in de minimus releases (Honeywell 2014a). Such activities and related exposure is anticipated to occur within 15

- 30 minutes (per event/day). The methodology used for this screening assessment is described in Chapter 5 of the Backgr ound Document. A box

- model approach was used to evaluate potential worker exposure to alternative refrigerants. This approach has been widely used for many years to estimate probable exposures of workers to hazardous airborne materials, and has been descri bed in detail by the National Institute for Occupational Safety and Health (NIOSH). This model takes into consideration the duration and magnitude of the resulting exposure which is influenced by 1) duration and intensity of the release, 2) rate at which
c ontaminated air is diluted with uncontaminated air, 3) proximity of the worker to the source of the release, and 4) the length of time the worker remains in the affected space.Final

-- October 10, 2014 7 The release per event was assumed to be 1 percent of the equipment charge during installation 5 and was multiplied by the number of installations estimated to occur over a workday. The analysis models the maximum anticipated charge sizes for cold storage warehouse and industrial process refrigeration systems , as provided by the s ubmitter

. To evaluate the risk of exposure at installation, t he maximum 15

- minute time weighted average (TWA) exposure s for each R

- 4 50 A constituent were estimated for the installation exposure scenario and compared to their respective short

- term exposure l imits . Because HFO

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

- 134a, and is not currently listed as acceptable for use in cold storage warehouse or industrial refrigeration end

- uses, Table 6 displays only HFO

- 1234ze(E), the component with greater potential concerns. Table 6 . Occupational Risk Assessment at Installation for HFO

- 1234ze(E) Component a
Equipment Scenario Charge Size (kg) 15
- minute TWA Occupational

Exposure (ppm) 15
- min STEL (ppm) 1 % Release Cold Storage Warehouse Reasonable Worst

- Case Scenario 1a 300 167 2,400 b

Reasonable Worst

- Case Scenario 1b 410 283 Industrial Process Refrigeration Reasonable Worst

- Case Scenario 2a 500 279

Reasonable Worst

- Case Scenario 2b 12,000 8,270 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 EPA

- derived STEL (see Table 3) Based on the assumptions described above, the modeling indicates that short

- term (15

- minute) worker exposure concentrations of the HFO

- 1234ze(E) component of R

- 450A are not likely to exceed its STEL (i.e., 2,400 ppm) in cold storage warehouse equipment for the typical and maximum p roposed charge size as well as in industrial process refrigeration equipment for the typical proposed charge size

. I n R easonable Worst

- Case Scenario 2 b , the modeling indicates worker exposure concentrations are likely to exceed the STEL for HFO

- 1234ze(E) for the maximum proposed charge size in industrial process refrigeration (i.e. 12,000 kg), as provided by the submitter ; however, all of the estimated exposures are significantly lower than the acute toxicity exposure limit (ATEL) of 59,000 ppm for HFO

- 1234ze(E), which is a refrigerant concentration limit intended to reduce the risks of acute toxicity hazards in normally occupied, enclosed spaces accordi ng 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). T he 12 ,000 kg charge is representative of a very large system, and as such, addit ional precautions are appropriate for industrial process refrigeration applications. F urthermore, the modeling assumptions do not reflect the use of any local exhaust ventilation or other engineering controls , which are likely to be used during installatio n, servicing, and disposal operations , thereby prevent ing significant exposure to R

- 450A

. Industrial process refrigeration systems are complex systems used in various types of manufacturing industries and are installed in large manufacturing facilities. Such facilities are already equipped with proper engineering controls and industrial hygiene practices for safety purposes a nd therefore are expected to have the capabilities to mitigate exposures to any large releases of refrigerant from the refrigeration system. Facility personnel are also equipped with proper PPE and trained to work in such environments that contain numerous workplace hazards , and are expected to be only at marginally incremental risk for exp osures to refrigerant releases in these settin gs. Furthermore , these types of systems are typically installed, maintained, and disposed of by trained and

5 IPCC (2006) estimate s that first

- fill losses during installation of industrial refrigeration systems in food process ing and cold storage warehouse systems can range from 0.5% to 3% ; DECC (2011) estimates that first

- fill losses for cold storage and industrial process refrigeration is approximately 1%; and , SKM Enviros (2011) suggests that this loss rate should be less th an 4%. A proposed update to EPA’s Vintaging Model recommends a first

- fill emissions rate of 1 % from cold storage and industrial process refrigeration manufactured after 1990.Final

-- October 10, 2014 8 EPA Section 608

- certified refrigerant technicians using proper industrial hygiene techniques . W hen installing, servicing, or disposing of cold stora ge and industrial process refrigeration systems , these techniqu es should be strictly followed. Adherence to the proposed substitute’s MSDS and use of proper engineering controls and PPE make it unlikely that exposure to R

- 450A would occur

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

- 450A. Engineering controls should include vapor

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

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

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

- resistance gloves whe n handling cylinders and chemically

- resistant gloves when handling the gas mixture (e.g., butyl rubber, chlorinated polyethylene, or neoprene). Toxicity risks would be further minimized by t he installation of signage which warns room occupants to remain standing (as higher concentrations are likely to accumulate near the floor) and to not enter recessed parts of the facility (e.g. maintenance crawl spaces and below grade service areas) and exit the facility immediately should they hear the refrigerant det ector alarm and/or smell the leaked refrigerant

. EPA believes that if proper handling and disposal guidelines are followed in accordance with good industrial hygiene practices and the MSDS for R

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

- 450A in cold storage warehouses and industrial process refrigeration

. In addition, as for other halogenated refrigerants, there is a risk of generation of toxic degradation products such as hydrogen fluoride and hyd rogen chloride if the components of R

- 450A (i.e., HF C

- 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

- sealed receptacles and should not be allowed to contact open flames, glowing metal surfaces, or electrical heating elements. EPA believes that when proper handling and disposal guidelines are followed in accordan ce with both good industrial hygiene practices and the MSDS for R

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

- 450A

. 

### 8
. GENERAL POPULATION EXPOSURE ASSESSMENT
R

- 450 A 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 cold storage warehouses and industrial process refrigeration systems

. The proposed substitute will be manufactured in a closed process and is proposed for use in closed systems ; thus, significant releases are not anticipated. At room temperature, R

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

- 450 A 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

- 4 50 A). Should air releases during manufacturing operations occur, engineering controls should be used (e.g. , carbon absorption scrubbers) to collect R

- 450 A and prevent the release of R

- 4 50 A to the atmosphere. EPA believes that by using proper engineering controls and by following disposal and containment recommendations outlined in the proposed substitute’s MSDS, exposure to R

- 4 5 0 A is not expected to pose a significant toxicity risk to the general population.Final

-- October 10, 2014 9 

### 9
. REFERENCES ACGIH. 2012. Guide to Occupational Exposure Values. American 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.
F orster, 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 Ch ange 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.)]. Cam

bridge 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. 2014a. Solstice® N

- 13 (R

- 45 0 A) . 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

- 13 (R

- 450A) Significant New Alternatives Policy Program Submission to the United States Environmental Protection Agency. August 11, 2014. ICF. 1997. Phy siological Effects of Alternative Fire Protection Agents

- Hypoxic Atmospheres Conference. Stephanie Skaggs prepared the proceedings of the conference held May 22, 1997 in New London, CT.

IPCC. 2006

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nggip.iges.or.jp/public/ 2006gl/pdf/3_Volume3/V3_7_Ch7_ODS_Substitutes.pdf. McQuay International (2011). Personal communication between Jim Henley (McQuay International) and Pamela Mathis (ICF International). 14 November 2011. OSHA. 2004. “Safety and Health Topics: Isobutane.” February 2004. Available online at: <http://www.osha.gov/dts/chemicalsampling/data/CH_247840.html>. SKM Enviros (2011). Comments provided by Ray Gluckman of SKM Enviros to ICF International in response to request for stakeholder input on the UK DECC Dra ft Refrigeration/AC GHG Inventory Assumptions. September 2011.Final

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