Final

-- October 10 , 2014 1 

## Significant New Alternatives Policy Program Refrigeration and Air Conditioning Sector Risk Screen on Substitutes in Chillers and Industrial Process Air - Conditioning 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 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 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 with in 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 presented in a series of Background Documents that are available in EPA's docket. The purpose of this risk screen is to supplement EPA’s Background Document on the refrigeration and air conditioning sector (EPA 1994) (hereinafter referred to as the Background Document) . This risk screen eval uates the potential use of R

- 450 A as a substitute i n the chillers en d

- use (specifically, centrifugal, reciprocating, screw, and scroll chillers) and the industrial process air

- conditioning end

- use . Table 1 presents the composition of the propos ed 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 % 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 Assessment  S ection 5 : Potential Health Ef fectsFinal

-- October 10 , 2014 2  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 for chillers and industrial process air

- conditioning
. 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 including CFC

- 11, CFC

- 12 , HCFC

- 22 , HCFC

- 123, and R

500 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 manufacture, installation and servicing, and disposal of chillers and industrial process air

- conditioning using R

- 450 A
. Because chillers and industrial process air

- conditioning systems are to be installed in locations with adequate space and/or ventilation in accordance with EPA recommendations and the equipment maintenance manual s for R

450 A in each end

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

- 450 A 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 chillers and industrial process air

- conditioning 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 presents an as sessment of the potential risks to atmospheric integrity posed by the use of R

450 A in chillers and industrial process air

- conditioning . The ozone depletion potential ( ODP ) , global warming potential ( GWP ) , and atmospheric lifetime (ALT) of the proposed su bstitute are presented in 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

11, CFC

- 12, HCFC

- 22, HCFC

- 123, and R

- 500
. In addition, R

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

- 134a, HFC

- 236fa , and R

- 407C . Thus, EP A

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 ref rigerants. Safety classifications based on toxicity 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 S ection 7).Final

-- October 10 , 2014 3 believes that the use of R

- 450 A would result in substantially less harm to the climate and ozon e layer than the continued use of ODS and commonly used refrigerants
. 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
- 11 1.0 4,750 45 CFC
- 12 0.82 10,900 100 R
- 50 0 e 0.7 8,077 NA f HCFC
- 22 0.13 1,810 12 HCFC
- 123 0.01 77 1.3 HFC
- 134a 0 1,430 14 HFC
- 236fa 0 9,810 240 R
- 407C g 0 1,774 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 A LT 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 et al., 201 3). d Hodn ebrog et al. ( 2013 ) e R
- 500 is a blend consisting of CFC
- 12 (73.8%) and HFC
- 152a (26.2%). f Atmospheric lifetimes are not given for blends, because the components separate in the atmosphere. The ALT for CFC
- 12 is 100 years and HFC
- 152a is 1.4 years (IPCC 4 th Assessment Report [Forster et al. 2007]). g R
- 407C is a blend consisting of HFC
- 32 (29%) , HFC
- 125 (25%) and HFC
- 134a (52%). h Atmospheric lifetimes are not given for blends, because the components separate in the atmosphere. The ALT for HFC
- 32 is 4.9 years, the ALT for HFC
- 125 is 29 years, and t he ALT for HFC
- 134a is 14 years (IPCC 4 th Assess ment 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 chillers and industrial process air

- conditioning , EPA identified the relevant toxicity threshold 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 A SHRAE 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 lower flammability limit, 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 exposure analysis, potential risks from chronic and acute worker exposure were evaluated by comparing exposure concentrations to available occupational exposure limits. Potential risks of chronic worker exposure were evaluated usi ng workplace guidance levels (WGL). Risks from potentialFinal

-- October 10 , 2014 4 short

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

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

- 450A , potential short

term, end

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

- 134a and HFO

- 1234ze (E) ). Table 3 lists the relevant toxicity 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 ) b 8,000 (10
- min AEGL
- 1) 8,0 00 (30
- min AEGL
- 1) 50,000 HFO
- 1234ze (E) 800 ( 8
- hour WEEL ) b 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 Alt hough 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 Administration NIOSH National Institute for Occupational Safety and Health ACGIH American Conference of Governmental Industrial Hygienists AIHA American Industrial Hygiene Association OARS Occupational Alliance for Risk Science Exposure Limit Definition Explanation Short - Term Exposure RCL Refrigerant Concentration

Limit The RCL for a refrigerant is intended to reduce the risks of acute toxicity, asphyxiation, and flammability hazards in normally occupied, enclosed spaces. The RCL for each refrigerant is the lowest of the Acute
- Toxicity Exposure Limit (ATEL), Oxygen Deprivation Limit (ODL), and Flammable Concentration Limit (FCL). Determination assumes full vaporization with no removal by ventilation, dissolution, reaction, or decomposition and complete mixing of refrigerant in the space to which it is released. ATEL Acute Toxicity Exposure Limit The ATEL is 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

.Final

-- October 10 , 2014 5 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 TL V

– 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 asymptomatic nonsensory effects. However, the effects are not disabling and are transient and reversible upon cessation of exposure. Acute Exposure Guideline Level 2 AEGL
- 2 is the airborne concentration (expressed as ppm or mg/m3) of a substance above which it is predicted that the general population, including susceptible individuals, could experience irreversible or other serious, long
- lasting adverse health effects or an impaired ability to escape. Acute Exposure Guideline Level 3 AEGL
- 3 is the airborne concentration (expressed as ppm or mg/m3) of a substance above which it is predicted that the general population, including susceptible individuals, could experience life
- threatening health effects or death. Long - Term Exposure PEL Permissible Exposure Limit This is an 8
- hour 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 Workplac e 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 be 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 qu alified 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 s kin 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 with 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 tha t person(s) immediately flush the eyes, including under the eyelids, with copious amounts of water for 15 minutes. EPA’s review of the human health impacts of this proposed substitute is contained in the public docket for this decision. These risks and pr ocedures after exposure are similar for other common refrigerants
. TheFinal

-- October 10 , 2014 6 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. 

### 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 flammability risk in the chillers and industrial process air

- conditioning end

- uses . 

### 7 . OCCUPATIONAL EXPOSURE ASSESSMENT To ensure that use of the proposed substitute in chillers and industrial process air

- conditioning does not pos e an unacceptable risk to workers during installation, servicing , and disposal, occupational exposure modeling at installation was performed for the proposed substitute. Although modeling is only performed for installation, it is assumed that exposure during servicing and disposal would not exceed exposure during installation because similar refrigerant charging and/or recovery equipment would be used . All installation, maintenance, and disposal activities for R

- 450A chillers and industrial process air

conditioning systems are anticipated to occur on

- site. The submitter anticipates that R

- 450A chillers will have typical a charge size of 700 kg up to 2,000 kg for centrifugal chillers and 80 kg to 100 kg for industrial reciprocating, and screw chillers. I ndustrial process air

- conditioning system charge sizes can vary greatly by construction (i.e., self

- contained or built in situ ). A 40

- ton built in situ system would have a charge size ranging from 85 to 95 kg of R

- 450A (Honeywell 2014 b ). The anticipated m aximum and typical charge sizes for the proposed applications are summarized in Table 5
. Table 5 . Typical and Maximum Charge Sizes for R - 450A Chillers and Industrial Process Air Conditioning Applications End - Use Application Typical Charge Size (kg) Maximum Charge

Size (kg) Chillers Centrifugal, commercial buildings 700 2,000

Industrial, reciprocating/screw compressors (varies by load, application, and refrigerant feed) 80 100 Industrial Process Air
- Conditioning * Built in situ system 85 95

* Varies greatly by construction. Systems can be self
- contained or built in situ

. Servicing of R

- 450A chillers and industrial process air

- conditioning systems is assumed to not exceed exposures during installation and disposal. Installation and disposal are anticipated to have similar exposures, since both require the use of similar refrigerant charging and/or recovery equipment as well as the connection of pipes to transfer the refrigerant; because it is likely that less refrigerant remains in the unit at di sposal, it is assumed that installation of a chiller or industrial process air

- conditioning system would require transfer of a greater amount of refrigerant, and thus result in greater worker exposure. Thus, occupational exposure was conservatively modeled based on installation. Installation of chillers and industrial process air

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

- 30 minutes (per event/day). To evaluate the risk of exposure atFinal

-- October 10 , 2014 7 installation, the maximum modeled exposure concentration was compared to 2,640 ppm, the R

- 450A STEL developed by EPA ba sed on R

- 450A’s 880 ppm AEL value. The methodology used for this screening assessment is described in Chapter 5 of the Background Document. A box

- model approach was used to evaluate potential worker exposure to alternative refrigerants. This approach has been widely used for many years to estimate probable exposures of workers to hazardous airborne materials, and has been described in detail by the National Institute for Occupational Safety and Health (NIOSH). This model takes into consid eration the duration and magnitude of the resulting exposure which is influenced by 1) duration and intensity of the release, 2) rate at which contaminated air is diluted with uncontaminated air, 3) proximity of the worker to the source of the release, and 4) the length of time the worker remains in the affected space. The release per event was assumed to be 0.2 percent of the equipment charge during installation 5 and was multiplied by the number installations estimated to occur over a workday. The analysis models the maximum anticipated charge sizes for chillers and industrial process air

- conditioning, as provided by the submitter (i.e., 2,000 kg and 95 kg, respectively). The maximum 15

- minute time weighted average (TWA) exposures for R

- 450A wa s estimated for the installation scenario and compared to the short

- term exposure limit for R

- 450a (see Table 6 )
.

Table 6 . Occupational Risk Assessment at Charging and Servicing for R - 450A a Equipment Charge Size (kg) 15 - minute TWA Occupational

Exposure (ppm) 15 - min Short Term Exposure Limits (ppm) 0.2% Release Centrifugal Chiller 2 , 000 530 2,640 b Built in situ Industrial Process Air
Conditioner 95 100 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 are not likely to exceed the STEL (2, 64 0 ppm) for R

- 450A for the maximum charge size for either equipment type. In addition, these types of systems are typically installed, maintained, and disposed by trained and EPA Section 608

- certified refrigerant technicians using proper industria l hygiene techniques . W hen installing, servicing, or disposing of large chillers, these techniques 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 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 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 gl oves when handling cylinders and chemically

- resistant gloves when handling the gas mixture (e.g., butyl rubber, chlorinated polyethylene, or neoprene). EPA believes that if proper handling and disposal guidelines are followed in accordance with good indust rial 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 chillers and industrial process air

- conditioning.

5 IPCC (2006) estimates that first

- fill losses during installation of chillers can range from 0.2% to 1% and DECC (2011) estimates first

- fill losses for chillers is approximately 0.5% ; however, industry representatives indicate that the first

- f ill leak rate for chillers is lower than 0.5% (McQuay 2011). A proposed update to EPA’s Vintaging Model recommends a first

- fill emissions rate of 0.2% from chillers manufactured after 1990.Final

-- October 10 , 2014 8 In addition, as for ot her halogenated refrigerants, there is a risk of generation of toxic degradation products such as hydrogen fluoride and hydrogen 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 accordance with both good industrial hygiene practices and the MSDS for R

- 450A and its components , there is no significant risk to workers during t he 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 chillers and industrial process air

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

- 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). S hould 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 50 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: Ve ntilation for Acceptable Indoor Air Quality. American Society of Heating, Refrigerating and Air

- Conditioning Engineers, Inc. Forster, P., V. Ramaswamy, P. Artaxo, T. Berntsen, R. Betts, D.W. Fahey, J. Haywood, J. Lean, D.C. Lowe, G. Myhre, J. Nganga, R. Prinn, G. Raga, M. Schulz and R. Van Dorland. 2007. Changes in Atmospheric Constituents and in Radiative Forcing. In: Climate Change 2007:The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. C ambridge 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 o f 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 Submissi on 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, 199 7 in New London, CT. 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://w ww.ipcc

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>. 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

- greenhouse

gas - inventory

- improvement

- project

- deve.PDF
.Final

-- October 10 , 2014 10 U.S. EPA 1994. Significant New Alternatives Policy Technica l 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. Avai lable online at: http://www.epa.gov/oppt/aegl/pubs/define.htm
. WMO (World Meteorological Organization), 2011. Scientific Assessment of Ozone Depletion: 2010 , Global Ozone Research and Monitoring Project

- Report No. 52, 51 6 pp., Geneva, Switzerland
.