A S TRUST & HOLDINGS INC. 

44-129 MIKIOLA DRIVE, KANEOHE, HI 96744 

PHONE: 808 2351890 FAX: 808 2350116 CELL: 808 5614688 

EMAIL Richard@astrust.com WEB SITE www.hcr188c.com 

Richard H. Maruya 

September 2, 2014 

Rebecca Von Dem Hagen 

Alternatives and Emissions Reduction Branch 

Stratospheric Protection Division 

U.S. Environmental Protection Agency 

1310 L Street, NW, 10th Floor 

Washington, DC 20005 

RE: Use of R443A and R441A HC refrigerants in air conditioning (AC) systems, per phone conversation 

with Richard Maruya, Margaret Sheppard, Cindy Newberg and Rebecca VonDemHagen, 21August2014, 

plus Comments on Federal Register Proposed Rules (FR DOC 2014 15889, 9 July 2014) 

Summary of Topics/Concerns: 

1) Propylene (a component of R443A) - is this toxic? No. 

a. We have included industry standard reference information to prove this. 

b. We think perhaps you confused propylene with propylene glycol. 

2) What is the exposure risk associated with dropping a window air conditioning unit containing R443A 

(i.e., a catastrophic leak)? Negligible. 

a. We have explained this in our previously supplied R443A Risk Assessments (SNAP Application 11 

February 2013, SNAP Incompleteness Response 7 March 2014, and SNAP Addendum 17 May 

2014), but we are attaching the important pages for you again, with the relevant pages/sections 

highlighted. 

b. We have also added a Sizing Guide for Maximum Allowable Charge for R443A vs Flammability. 

3) Are we correct that if this Federal Register Proposed Rule is accepted. R441A will be accepted by the 

EPA for use in all of the following categories (see p33813) and that this acceptance equals the EPA 

having accepted the four following SNAP applications for these categories as submitted by A.S. Trust 

to the EPA on the dates listed as both complete AND listed on the Federal Register? 

a. Use of R441A in Household Window AC units (Notified as Complete, November 2008) 

b. Use of R441A in Vending Machines (Notified as Complete, May 2012) 

c. Use of R441A in New Commercial Refrigerators, Commercial Freezers and StandAlone Refrigerated Display Cases (Notified as Complete, September 2012) 

d. Use of R441A in New Residential Split-System AC Units, Residential Heat Pumps, 

And Portable (Floor) Room Air Conditioners (Submitted February 11, 2013) 

1 
NOTE: These four applications/listings are in addition to the previously Federal Register-listed 

(December 20, 2011) EPA SNAP approval of R441A for use in Household Refrigerators and Stand-Alone 

Freezers. 

4) We want to go on record as supplying the following Comments (during the 60-day comment period) 

on the Federal Register Proposed Rules {FR DOC 2014 15889, 9 July 2014). Since the EPA's 

Stratospheric Office is all about the importance of refrigerants of zero or exceedingly low GWP and 

ODP, we are absolutely astounded that the EPA would propose the approval of R32 (GWP 675) for 

any new applications given that HCs are available with GWP <10 {R441A} AND with R32 being 

highly toxic. Yet, the EPA states it is concerned about toxic substances (see (1) above). In addition, 

we are very surprised at the large allowed charge amount for R32, given its flammability. 

a. See attached document that discusses the strong concern voiced in other countries about the 

toxic fluorides released when refrigerants in this group burn. 

Attachments 

A - Propylene data-sheet/The Linde Group 

B - Response by Muhammed Ashraf, Senior Chemist, ComStar International Inc. 

C - Excerpt, Supplemental Report on the Use of R443A in Residential Split-System Air Conditioning and 

Heat Pump Units, and in Portable Room Air Conditioners, Gary Whitmyre, February 28, 2014 

D - R443A/R441A Sizing Guide for Maximum Allowable Charge in Portable Air Conditioning Units, Gary 

Whitmyre, August 2014 

E - National Refrigerants R32 MSDS 

F - "Honeywell on Refrigerant Price Offensive," www.FridgeHub.com/NEWS/, 2014 

2 
Detailed Responses 

1) Is propylene (a component of R443A) toxic? NO. 

Someone may have confused propylene with propylene glycol. These are two different substances. 

Propylene is (C3H6) is a colorless non-toxic gas; see Attachment A (Propylene data-sheet/The Linde 

Group) and Attachment B (Response by Muhammed Ashraf, Senior Chemist, ComStar International Inc.) 

2) What is the exposure risk associated with dropping an air conditioning unit containing R443A 

(i.e., a catastrophic leak}? NEGLIGIBLE. 

a) The EPA is concerned about the likelihood of dropping an air-conditioning unit containing 

R443A, such that it punctures the refrigerant tubing inside and releases all the R443A at once. The 

chances of this are very small: when it is still in its packaging, an AC unit is purposely protected with 

cushioning against just such damage. A mechanical engineer designs the packaging and performs droptests on packaged units before the packaging is approved for manufacture and use. 

In our SNAP application for New Residential Split-System Air Conditioning Units, Residential heat Pumps, 

and Portable (Floor) Room Air Conditioners (submitted February 11, 2013), we included calculations for 

airborne concentrations of R443A for exposure due to catastrophic (1 minute for complete charge loss) 

in residential settings; see Attachment C, highlighted sections (Excerpt, Supplemental Report on the Use 

of R443A in Residential Split-System Air Conditioning and Heat Pump Units, and in Portable Room Air 

Conditioners, Gary Whitmyre, February 28, 2014) 

b) To address concerns about charge size versus flammability, we have added a new chart that 

shows maximum allowable charge of R443A per room volume, which keeps the air concentration below 

the lower flammability limit; see Attachment D (R443A/R441A Sizing Guide for Maximum Allowable 

Charge in Portable Air Conditioning Units, Gary Whitmyre, August 2014). Since the LFL of R441A is 

almost identical to that of R443A, this sizing guide would also apply to the use of portable AC units 

charged with R441A. 

3) According to the Proposed Rules of July 9 (Federal Register DOC 2014 15889), page 38813, Section 

IB, R441A will be accepted by the EPA for use in window AC units, packaged terminal AC units and heat 

pumps, portable room AC units, stand-alone commercial refrigerators and freezers, household 

refrigerators and freezers, and vending machines. This statement of acceptance would appear to equal 

the EPA having both accepted as "COMPLETE" and "LISTED ON THE FEDERAL REGISTER", the four A.S. 

Trust SNAP applications listed below (as deemed Complete or as Submitted to the EPA on the dates 

shown). IS THIS CORRECT? 

a. Use of R441A in Household Window AC units (Notified as Complete, November 2008) 

b. Use of R441A in Vending Machines (Notified as Complete, May 2012) 

3 
c. Use of R441A in New Commercial Refrigerators, Commercial Freezers and StandAlone Refrigerated Display Cases (Notified as Complete, September 2012) 

d. Use of R441A in New Residential Split-System AC Units, Residential Heat Pumps, 

And Portable (Floor) Room Air Conditioners (Submitted February 11, 2013) 

NOTE: These four applications/listings would be in addition to the previous (December 21, 2011) EPA 

SNAP approval of R441A already listed on the Federal Register for use in Household Refrigerators and 

Stand-Alone Freezers. 

In other words, if/when the Proposed Rule is accepted, does it leap-frog all relevant documents that 

have been hanging unanswered and immediately put the stamp of official approval on the abovementioned four A.S. Trust SNAP applications so that U.S. industrial manufacturers can start using 

R441A? 

4) We are absolutely astounded that the EPA would propose the approval of R32 (GWP 675) for any 

new applications when HCs are available with GWP <10 (R441A) AND with R32 being highly toxic 

when burning. 

a) We have included the Material Safety Data Sheet for R32, indicating the toxicity; see 

Attachment E (National Refrigerants R32 MSDS) 

b) We have included a recent article highlighting grave concerns about the toxic chemicals released 

when R1234yf (which is similar in GWP and toxicity to R32) burns; see Attachment F 

("Honeywell on Refrigerant Price Offensive," www.FridgeHub.com/NEWS/, 2014). We are also 

very concerned about the high charge amount proposed to be allowed for R32, given its 

flammability and extreme toxicity, when compared to the small charges that are sufficient for 

currently available HC refrigerants to work efficiently. 

4 
Copyrighted page(s) removed. Copyrighted 

material is not available in Regulations.gov since 

it may not be reproduced without consent of the 

copyright holder. 

Removed pages can be viewed at the USEPA 

Docket Center, Public Reading Room. 

Address: 1301 Constitution Ave, NW 

Room 3334 

Washington, DC 20004 

Telephone: 202-566-1744 

Email: docket-customerservice@epa.gov
August 22, 2014 

Richard Maruya 

A.S. Trust & Holdings Inc. 

44-129 Mikiola Drive 

Kaneohe, HI 96744 

Reference: Propylene (propene), toxicity 

Dear Mr. Maruya: 

As noted in the Wikipedia attachment to this cover letter, propylene (also known as 

propene, CAS # 115-07-1) is not listed by the U.S. EPA as a hazardous air pollutant 

under the Clean Air Act (see Environmental Safety section). Also, with a relatively short 

half-life, it is not expected to bioaccumulate. Lastly, propylene has low acute toxicity 

from inhalation and is considered non-toxic. 

Senior Chemist 

ComStar International Inc. 

20-45 128 Street 

College Point, NY 11356 

Phone: (800) 328-0142 

Fax: (7 18)353-5998 

Email: customerservice@comstarproducts.com 

Website: www.comstarproducts.com 

B
B
B
B
B
B
C
(4) Zonal modeling of exposures tor the whole house residential setting. 

The airborne concentrations of R-443a in different rooms or zones of residential airspace 

resulting from hypothetical leaks from the evaporator of a residential split-system air 

conditioning or heat pump system located in HV AC components in a utility room were modeled 

using the Multi-Chamber Concentration and Exposure Model, or MCCEM (USEPA 199la). A 

range of emission rates was assumed to cover both "high-end" non-catastrophic release and 

catastrophic release scenarios. A "high-end" release rate was assumed to be loss of the entire 

charge over the course of a 30-day period in the case of the split-system residential air 

conditioner or heat pump. Thus, a linear loss rate of l/301

h of the initial charge per day would 

occur until the pressure drop results in activation of the safety valve. In our calculation, we have 

assumed the worst-case scenario, which is that the safety valve does not activate. As an 

example, for a 416 g charge of R-443a sized to a 1600 ft2 house, the average emission rate for 

the "high-end" release scenario would be: (416 g) x (1/30 days) x (day/24 hrs)= 0.578 g/hour. 

For the "catastrophic" release scenario, the full charge of R-443a was assumed to be released 

into the utility room or furnace room within 1 minute from sudden rupture of the evaporator 

coils. Initial dilution of a release would be to airspace of the specific room where the appliance is 

located, with eventual dilution into adjacent rooms and the entire house volume. 

In order to be conservative and to also simplify this 4-zone modeling approach, it was assumed 

that the utility room (Zone 1 ), adjacent living room (Zone 2), and kitchen (Zone 3) have no air 

exchange directly with outdoor air. The only zone with air exchange rate with outdoor air was 

assumed to be the remainder of the house (Zone 4), for which the air exchange rate of 0.5 ACH 

was assigned, equivalent to the median national value across seasons (Pandian et al. 1998). Air 

exchanges between zones were assigned on the order of0.5 ACH as well. 

Using these assumptions, MCCEM was run in the short-term mode in 1 minute steps for 8-hours 

to obtain summary output statistics. The modeled 8-hr average and maximum airborne 

concentrations for each of the 4 zones based on MCCEM modeling of R-443a in the residential 

settings shown in Table 6. These results are for the "high-end" release scenario in which the 

safety valve does not activate (100 percent loss ofR-443a over 30 days), and for the catastrophic 

release scenario, also for which it was assumed that the safety valve does not activate. Graph 1 

illustrates the time-concentration profile for R-443a in the 4 zones from catastrophic release of 

R-443a in a 1600 ft2 house, originating in the utility room. A pattern of increasingly lower 

concentrations in rooms or zones more distal to the source of release in the utility room was 

observed in all cases. Because the source release is limited in time to 1 minute at the start of the 

modeling period, levels ofR-443a rapidly decline in all 4 zones due to dilution and air exchange. 

For the more gradual "high-end" release of R-443a into the airspace of a utility room, migration 

of R-443a throughout the house occurs rapidly. The airborne levels of R-443a rise over time in 

each of the affected zones, with the levels in the utility room and adjacent living room rising 

more than those in more distal rooms. In all rooms, the airborne levels of R-443a plateau as the 

source term (gradual refrigerant release in utility room) comes into equilibrium with air 

exchange in the house. 

16 

C
Table 6. MCCEM Modeling of Air Levels ofR-443a in Residences Associated With 

H LVPO th e ti ca 1 R e 1 eases F E rom xampe 1 A" Ir-C on d"f I 1onme: S •VS t ems /H ea t P umps 

House Release Concentration of Concentration of Concentration of Concentration of 

Floor Scenario R-443a (mg/m3): R-443a (mg/m3

): R-443a (mg/m3): R-443a (mg/m3

): 

Area 'Zone I 'Zone 2 czone 3 'Zone4 

(tf) 8-hour" I-min 8-hour" I-min 8-hour" I-min 8-hour" I-min 

avel1li!e max. average max average max average max 

I600 Hi Ph-end' 28.7 47.5 13.6 27.2 5.38 12.5 0.523 1.49 

Catastrophic' 4.270 9,420 2,450 2,960 1,130 1,430 134 203 

3700 High-end' 48.7 83.1 22.6 46.2 8.I2 19.4 0.625 1.83 

Catastroohic' 7,440 14,000 4,140 4,900 1,740 2,220 164 259 

6000 High-end' 52.5 90.5 24.6 50.9 9.52 22.7 0.598 1.75 

Catastrophic" 8,140 14,800 4,580 5,380 2,050 2,610 158 250 

'Release of the full charge amount ofR-443a at a lmear rate over 30 days; worst-case assuming safety valve does 

not function properly; split-system air conditiooing and heat pump charge amounts ofR-443a are 416 g for a unit 

sized to a 1600 tf house; 1440 g for a unit sized to a 3 700 tf house; and 2450 g for a unit sized to a 6000 tf house; 

b Worst-case hypothetical catastrophic release of the entire charge from split system unit in 1 minute. 

'Zone l =utility room/furnace room; Zone 2 =living room; Zone 3 =kitchen; Zone 4 =other areas of the house. 

'Adjusted 8-hour average concentration for the zone in which the individual is located. 

4-Zone Modeling in 1,600 Sq. Ft. House: R-443a Concentration From 

Sudden Release From Evaporator Coils in Utility Room 

1.00E+04. 

9.00E+03 ~::::::::;;::-. =--===----=:::-----------

c\'l 8.00E+03 1- --- .,. 7.00E+03 1-~~-----=--~----~--=:c---­

~ 6.00E+03 1---",------------'""-~cc--------...,.__ -0 5.00E+03 l 4.00E+03 

-: 3.00E+03 -r---____________ ::::_:_-:_:-_::-_ =--~=--.:. :.;: 2.00E+03 - - -- -

1.00E+03 I ~-

0. QQE+QQ -·=·'"'"'m.nrno.m.a •. mu~-"'''·'b"'P•LD.c>.c,pmm.d., •• ,.&,,,,n,,,,,,,,=•rn•n.Lb.u 

Time (minutes) 

! --Utility Room 

I 

Living Room 

I --Kitchen 1-- Remainder of House i 

Graph 1. Airborne concentration-time profile ofR-443a in 4 zones of a 1,600 ft2 house 

during a "catastrophic" release ofR-443a in the utility room HVAC system. 

17 

C
( 4) Comparison ofresidential exposure levels to toxicity benchmarks. Composite 

8-hour TWA concentrations were weighted for time spent in different portions of the residence, 

per the modeled adjusted 8-hour average airborne concentrations of R-443a as shown in Table 6. 

The potential exposures to R-443a for the residential receptor may involve 0.1 hours of exposure 

in the utility room, 2.5 hours of exposure in the adjacent living room, 1.6 hours in the kitchen 

and 3.8 hours in the remainder of the house. As an example, the composite 8-hour airborne 

concentration of R-443a, based on the zone-specific time-weighted average (TWA) airborne 

concentrations, was calculated as follows for the "catastrophic" release from the 1,600 ft2 house: 

[[(4270 mg/m3)*(0. l hr)]+[(2450 mg/m3)*(2.5 hr)J+[(l !30 mg/m3)*(1.6 hr)]+[(]34 mg/m3)*(3.8 hr)]] 

(8 hrs) 

= 1,110 mg/m3

, which is less than the 8-hour weighted TLV of 1,312 mg/m3 for R-443a. None 

of the 8-hour composite R-443a levels for the "high-end" 30-day release scenario exceed the 

calculated TL V of 1,312 mg/m3 for R-443a for either the 1600, 3700, or 6000 ft2 house. 

( 5) Comparison of Residential Exposure Levels to Flanunability Limits. The 

I-minute maximum airborne concentrations of R-443a in the 4 zones of the residence due to 

either the "high-end" or catastrophic release scenarios as modeled with MCCEM are shown in 

Table 6. In the case of a split-system air conditioner or heat pump for the 1,600 ft2 residence, 

the I-minute maximum levels of R-443a for the split system residential air conditioner were 

estimated by MCCEM to be highest in Zone I (the utility room) at 47.5 mg/m3 (26.4 ppm) for 

the "high-end" non-catastrophic release and 9420 mg/m3 (5230 ppm) for "catastrophic" release 

of R-443a into the residence. These maximum concentrations of R-443a in the utility room are 

only 0.13 percent of the LFL of20,300 ppm for the "high-end" release and 26 percent of the LFL 

in the case of the sudden catastrophic release. The I-minute maximum levels in the nearest room 

of the same house, the living room (Zone 2) are 27.2 mg/m3 (15.I ppm) for the "high-end" noncatastrophic release and 2960 mg/m3 (1640 ppm) for "catastrophic" release of R-443a into the 

residence. These maximum concentrations of R-443a in the living room are only 0.074 percent 

of the LFL of 20,300 ppm for the "high-end" release and 8. I percent of the LFL in the case of 

the sudden catastrophic release. The I-minute maximums for more distal rooms ( e.e., kitchen, 

remainder of house) continue to fall to lower levels as the receptor moves further from the source 

ofR-443a, which is located in the utility room. 

The highest I-minute maximum airborne levels of R-443a obtained in the modeling are for the 

release in the 6000 ft2 house. For this setting, the utility room is at 90.5 mg/m3 (50.3 ppm) for the 

"high-end" non-catastrophic release and 14,800 mg/m3 (8220 ppm) for sudden "catastrophic" 

release ofR-443a. These maximum indoor air concentrations ofR-443a for the 6000 ft2 house in 

the case of the split-system residential AC or heat pump are 0.25 percent of the LFL of 20,300 

ppm for the "high-end" release, and 40 percent of the LFL in the case of the sudden catastrophic 

release., The maxi~um 1-m~nute airbon::e levels of R-443a for the catastrophic release in the 

6000 [t- house, movmg to adjacent and distal rooms, range from 5380 mg/m (2990 ppm, or 15 

percent of the LFL) in the living room (Zone 2), to 2610 mg/m3 (1450 ppm, or 7.1 percent of the 

LFL) in the kitchen, to 250 mg/m3 (139 ppm, or 0.68 percent of the LFL) in the remainder of the 

house. The results indicate an adequate degree of safety for split system central residential air 

conditioners and heat pumps with respect to flammability. 

18 

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R-443a/R-441a Sizing Guide for Maximum Allowable Charge in Portable Air Conditioning Units 8/27/2014

Room

Volume Max

m3 Charge (g)

The maximum allowable charge size based on flammability is shown below for different room sizes.

7.2 78 Use of the maximum allowable charge size will keep the air concentration of R-443a below the lower flammability limit,

10.9 95 or LFL, should a sudden and complete release of the charge occur for any reason.

34 152

(Above data from July 9, 2014

rule per Federal Register,

Vol. 79, No. 131, pp 38811 to

38840 -- see Table 2, p 38825)

R-441 a nd R-443a have nearly

identical LFLs, so the sizing

guide applies to both

refrigerants for use in

portable AC units.

0

20

40

60

80

100

120

140

160

180

0 5 10 15 20 25 30 35 40

Max Allowable Charge (g)

Room Volume (m3)

Sizing Guide for R-443a Use in Portable AC Units

D
Material Safety Data Sheet 

R-32 

1. CHEMICAL PRODUCT AND COMPANY IDENTIFICATION

PRODUCT NAME: R-32 

DISTRIBUTOR: National Refrigerants, Inc. 

661 Kenyon Avenue 

Bridgeton, New Jersey 08302 

FOR MORE INFORMATION CALL: IN CASE OF EMERGENCY CALL: 

 (Monday-Friday, 8:00am-5:00pm) CHEMTREC: 1-800-424-9300 

 1-800-262-0012 

2. COMPOSITION / INFORMATION ON INGREDIENTS

INGREDIENT NAME CAS NUMBER WEIGHT %

Difluoromethane 75-10-5 100 

3. HAZARDS IDENTIFICATION

EMERGENCY OVERVIEW: This product is a flammable, liquefied gas. Contents under pressure. Cylinders may 

rupture and rocket under fire conditions. Thermal decomposition can produce toxic and corrosive gases. Vapors are 

heavier than air. May cause asphyxia. Liquid splashes or spray may cause freeze burns (frostbite). High vapor 

concentrations may cause dizziness or more severe anesthetic effects. Very high exposures can cause potentially fatal 

abnormal heart rhythm. Read the entire MSDS for a more thorough evaluation of the hazards. 

POTENTIAL HEALTH HAZARDS

SKIN: Liquid splashes or spray may cause freeze burns. 

SKIN ABSORPTION: This product will probably not be absorbed through human skin. 

EYES: Liquid splashes or spray may cause freeze burns. 

INHALATION: Exposure to high vapor concentrations can induce anesthetic effects progressing from dizziness, weakness, 

nausea, to unconsciousness. Very high exposures can cause abnormal heart rhythm, which is potentially 

fatal. It can act as an asphyxiant by limiting available oxygen. 

INGESTION: Extremely unlikely to occur in use. 

OTHER EFFECTS OF OVEREXPOSURE: None Expected. 

____________________________________________________________________________________________________________ 

MSDS: R-32 Page 1 of 7 

Current Issue Date: December, 2008 

E
R-32 

4. FIRST AID MEASURES

SKIN: Immediately wash with plenty of warm water (do not rub). Thaw affected area with water. Remove contaminated clothing. 

Caution: clothing may adhere to the skin in case of freeze burns. If symptoms (irritation or blistering) develop, get medical 

attention. 

EYES: Immediately flush with plenty of water. After initial flushing, remove any contact lenses and continue flushing for at least 15 

minutes. Hold eyelids open during flushing. Have eyes examined and treated by medical personnel. 

INHALATION: Move victim to fresh air. Keep warm and at rest. If breathing is labored, give oxygen. If only breathing has 

stopped, give artificial respiration with a pocket mask equipped with a on-way valve to prevent exposure to product 

or body fluids. If breathing has stopped and there is no pulse, give cardiopulmonary resuscitation (CPR). Get 

immediate medical attention. 

INGESTION: Highly unlikely, but should this occur, freeze burns will result. Do not induce vomiting unless instructed to do so by 

a physician. 

ADVICE TO PHYSICIAN: Symptomatic and supportive therapy, as indicated. Administration of epinephrine or similar 

 sympathomimetic drugs should be with special caution and only in situations of emergency life support 

 as cardiac arrhythmias may result. 

5. FIRE FIGHTING MEASURES

FLAMMABLE PROPERTIES

FLASH POINT: Not applicable 

AUTOIGNITION TEMPERATURE: Not available 

UPPER FLAME LIMIT: 31% (% v/v) 

LOWER FLAME LIMIT: 14% (% v/v)

HAZARDOUS REACTIONS: 

Reacts with finely divided metals such as aluminum, zinc, magnesium, and alloys containing more the 2% magnesium. Can 

react violently if in contact with alkali metals and alkaline earth metals such as sodium, potassium, or barium. 

During a fire the product can form toxic and corrosive gases such as hydrogen fluoride. 

EXTINGUISHING MEDIA: 

Suitable extinguishing medium is dry powder. Allow escaping gas to urn under controlled conditions. Extinguish only if 

escape of gas can be rapidly stopped as it may form a flammable vapor cloud. 

FIRE AND EXPLOSION HAZARDS: 

Flammable liquefied gas. Container may burst under intense heat. Ruptured cylinders may rocket or fragment. Heavy vapor 

 may suffocate. 

Certain mixtures of HFC-32 and chlorine may be flammable under some conditions. 

____________________________________________________________________________________________________________ 

MSDS: R-32 Page 2 of 7 

Current Issue Date: December, 2008 

E
R-32 

FIRE FIGHTING PROCEDURES: 

Water spray should be used to cool containers. 

FIRE FIGHTING PROTECTIVE EQUIPMENT: 

Use self-contained breathing apparatus with a full-face piece and special protective clothing. 

6. ACCIDENTAL RELEASE MEASURES

This product is a flammable, liquefied gas, which exits the container at temperatures capable of causing freeze burns (frostbite). 

Contents under pressure. Ruptured cylinder may rocket or fragment. 

Precautions should take into account the severity of the leak or spill. 

Move unprotected personnel upwind of leaking container. Remove ignition sources and ventilate the spill area. Use recommended

personal protection and shut off the leak, if without risk. If possible, elevate leak position to highest point of container (should leak 

gas, not liquid). Water should never be put on leak nor should cylinder be immersed. If possible, dike and contain spillage. Prevent 

liquid from entering sewers sumps, or pit areas since vapor is heavier than air and can create a suffocation atmosphere. Capture 

material for recycle or destruction if suitable equipment is available. 

Notify applicable government authority if release is reportable or could adversely affect the environment. 

7. HANDLING AND STORAGE

HANDLING: 

Wear appropriate personal protective equipment. A safety shower and eyewash station should be nearby and ready for use. 

This product is a flammable, liquefied gas, which exits the container at temperatures capable of causing freeze burns 

(frostbite). Ensure personnel are trained in handling and storing cylinders. Secure containers at all times. Keep containers 

closed when not in use. 

Ensure there is adequate ventilation or use proper respiratory protection in poorly ventilated or confined areas. Avoid 

causing and inhaling high concentration or vapor. Atmospheric levels should be controlled to below the occupational 

exposure limit and kept as low as practicable. 

Prevent liquid or vapor from entering sumps or sewers since vapor is heavier than air and may form suffocating atmospheres. 

Do not put mixtures of HFC-32 with air or oxygen under pressure; do not use such mixtures for leak or pressure testing. 

Do not heat containers. 

Liquid transfers between containers may generate static electricity. Ensure adequate grounding. 

Avoid trapping liquid between closed valves or overfilling containers as high pressures can develop with an increase in 

 temperature. 

Avoid HFC-32 contact with flames or very hot surfaces. 

____________________________________________________________________________________________________________ 

MSDS: R-32 Page 3 of 7 

Current Issue Date: December, 2008 

E
R-32 

STORAGE RECOMMENDATIONS:

Keep containers tightly closed, in a cool, well-ventilated place. Keep containers dry. Keep from incompatibles, open flames,

hot surfaces, welding operations, and other heat sources. 

STORAGE TEMPERATURE: 

Store at temperature not exceeding 125 deg. F. (52deg. C). 

8. EXPOSURE CONTROLS / PERSONAL PROTECTION

ENGINEERING CONTROLS: 

Use ventilation to maintain safe levels. Where appropriate engineering controls are not in place or are inadequate, wear 

suitable respiratory equipment. 

PERSONAL PROTECTIVE EQUIPMENT 

SKIN PROTECTION: 

Take all precautions to prevent skin contact. Use gloves and protective clothing made of material that has been 

found by user to be impervious under conditions of use to prevent the skin from becoming frozen for contact with 

liquid. User should verify impermeability under normal conditions of use prior to general use. Additional 

protection such as an apron, arm covers, or full body suit may be need depending on conditions of use. 

EYE PROTECTION: 

Use chemical safety goggles or safety glasses and a face shield when there is potential for eye contact. 

RESPIRATORY PROTECTION: 

Not normally needed if controls are adequate. If needed, use NIOSH/MSHA approved respirator for organic vapors. 

For high concentrations and oxygen-deficient atmospheres, use positive pressure air-supplied respirator. 

OTHER PROTECTION: 

Shower and eye wash station. 

EXPOSURE GUIDELINES

INGREDIENT NAME ACGIH TLV OSHA PEL OTHER LIMIT

Difluoromethane None None *1000 ppm TWA (8hr)

* = Workplace Environmental Exposure Level (AIHA)

Minimize exposure in accordance with good hygiene practice. 

9. PHYSICAL AND CHEMICAL PROPERTIES

APPEARANCE: Colorless liquefied gas 

ODOR: Faint ethereal odor 

SPECIFIC GRAVITY (water = 1.0): 0.98 at 20 deg. C 

SOLUBILITY IN WATER (weight %): Insoluble 

____________________________________________________________________________________________________________ 

MSDS: R-32 Page 4 of 7 

Current Issue Date: December, 2008 

E
R-32 

pH: Not applicable 

BOILING POINT: -51.7°C (-61.1°F) 

VAPOR PRESSURE (mmHg at 20 deg. C): 10,319 

VAPOR DENSITY (air = 1.0): 1.86 at normal boiling point 

% VOLATILES: 100 

10. STABILITY AND REACTIVITY

CHEMICAL STABILITY: 

Stable under normal conditions. 

INCOMPATIBILITIES: 

Reacts with finely divided metals such as aluminum, zinc, magnesium, and alloys containing more then 2% magnesium. Can 

react violently if in contact with alkali metals and alkaline earth metals such as sodium, potassium, or barium. 

HAZARDOUS DECOMPOSITION PRODUCTS: 

Hydrogen fluoride by thermal decomposition and hydrolysis. 

CONDITIONS TO AVOID: 

Keep away from heat, sparks, and flame. Avoid high temperatures. 

HAZARDOUS POLYMERIZATION:

Will not occur. 

11. TOXICOLOGICAL INFORMATION

POSSIBLE HUMAN HEALTH EFFECTS: 

Routes of Exposure: 

Inhalation, ingestion, eye, and skin contact. 

Inhalation: Exposure to high vapor concentrations may cause and abnormal heart rhythm and prove suddenly fatal. 

Very high atmospheric concentrations can cause anesthetic effects progressing from dizziness, weakness, 

nausea, to unconsciousness. It can act as an asphyxiant by limiting available oxygen. 

Ingestion: Highly unlikely, but should this occur, freeze burns will result. 

Eye Contact: Liquid splashes or spray may cause freeze burns. 

Skin Contact: Liquid splashes or spray may cause freeze burns. 

Other Effects: None anticipated. 

Carcinogenicity: 

Ingredient Name NTP STATUS ACGIH IARC STATUS OSHA LIST

No ingredients listed in this section 

ANIMAL DATA: 

 LC50 4 hr., (rat inhalation) - > 520,000 ppm 

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R-32 

Because of its volatility this compound has not been tested for skin or eye irritancy or skin sensitization. 

No cardiac sensitization (arrhythmias) occurred in dogs pretreated with epinephrine at 350,000 ppm. In an earlier cardiac 

sensitization study, a no observed effect level (NOEL) of 200,000 ppm and threshold of 250,000 ppm were established. 

No teratogenic effects were seen in rats or rabbits at dose levels up to 50,000 ppm. 

No adverse effects were seen at the highest dose level of 50,000 ppm in a 90-day inhalation. 

No genotoxicity was observed in a range of in vitro tests or an in vivo mouse micronucleus assay. 

12. ECOLOGICAL INFORMATION

PERSISTENCE AND DEGRADATION: 

Decomposes comparatively rapidly in the lower atmosphere (troposphere). Atmospheric lifetime is 4.9 years. 

Products of decomposition will be highly dispersed and hence will have a very low concentration. It is not 

considered an ozone-depleting chemical. 

EFFECT ON EFFLUENT TREATMENT: 

Discharges of the product will enter the atmosphere and will not result in long-term aqueous contamination. 

13. DISPOSAL CONSIDERATIONS

DISPOSAL METHOD: 

Discarded product is not a hazardous waste under RCRA, 40 CFR 261. However, HFC-32 should be recycled, reclaimed, or 

destroyed whenever possible. 

CONTAINER DISPOSAL: 

May contain explosive vapors. Do not distribute, make available, furnish, or reuse container when emptied of the original 

product. Do not weld or use cutting torch on or near container. Empty container retains product residue. Return containers 

 to supplier. 

REFRIGERATION APPLICATION: 

Subject to “no venting” regulations of Section 608 of the Clean Air Act during the service or disposal of equipment. 

14. TRANSPORT INFORMATION

US DOT HAZARD CLASS: US DOT PROPER SHIPPING NAME: Difluoromethane 

US DOT HAZARD CLASS: 2.1 

US DOT PACKING GROUP: Not applicable 

US DOT ID NUMBER: UN3252 

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15. REGULATORY INFORMATION

TSCA (TOXIC SUBSTANCES CONTROL ACT) REGULATIONS, 40 CFR 710: 

All ingredients are on the TSCA Chemical Substances Inventory. 

CERCLA and SARA REGULATIONS: 

40 CFR 372: This product does not contain any chemicals subject to reporting requirements of SARA Section 313. 

40 CFR 355: This product does not contain any “extremely hazardous chemical” subject to the requirements of SARA Section 312. 

40 CFR 370: Hazardous properties as defined under the Hazard Communication Standard (29 CFR 1910.1200). 

Health: Acute effects (CNS depression, cardiac sensitization). 

Physical: Flammable liquefied gas. 

(Actions may be necessary under SARA Section 311 – consult regulations for applicability). 

16. OTHER INFORMATION

CURRENT ISSUE DATE: December, 2008 

PREVIOUS ISSUE DATE: August, 2007 

OTHER INFORMATION: HMIS Classification: Health – 1, Flammability – 4, Reactivity – 1 

Regulatory Standards:

1. OSHA regulations for compressed gases: 29 CFR 1910.101

2. DOT classification per 49 CFR 172.101

17. DISCLAIMER

National Refrigerants, Inc. believes that the information and recommendations contained herein (including data and statements are 

accurate as of the date hereof. NO WARRANTY OF FITNESS FOR ANY PARTICULAR PURPOSE, WARRANTY OF 

MERCHANTABILITY, OR ANY OTHER WARRANTY, EXPRESSED OR IMPLIED, IS MADE CONCERNING THE 

INFORMATION PROVIDED HEREIN. The information provided herein relates only to the specific product designated and may not 

be valid where such product is used in combination with any other methods of use of the product and of the information referred to 

herein are beyond the control of National Refrigerants. National Refrigerants expressly disclaims any and all liability as to any results 

obtained or arising from any use of the product or reliance on such information. 

____________________________________________________________________________________________________________ 

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