Difluoromethane

52.02

52.02

200-839-4

77JW9K722X

3252

DTXSID6029597

Colorless gas|Colorless gas at ambient conditions

2903399090

0

0.30

Difluoromethane appears as a colorless odorless gas. Insoluble in water and has a high thermal stability. Its vapors are heavier than air. Under prolonged exposure to fire or intense heat the containers may rupture violently and rocket. Contact with the unconfined liquid can cause frostbite. Used as a refrigerant.

0.5265 g/cm³

-136 °C

-51.6 °C

-78.5±6.3 °C

1.196

Soluble in ethanol

Grounding and bonding required. Store in a tightly closed container. Store below 49 C. Store in a cool, dry place. Store in a well-ventilated area. Keep separated from incompatible substances.

1.26X10+4 mm Hg at 25 deg C

LC50 inhalation in mouse: 1810gm/m3

1.09e-14 cm3/molecule*sec

Henry's Law constant = 0.292 atm-cu m/mol at 25 °C (est)

Global Warming Potential (GWP): Chemical: HFC-32; GWP: 675 (100-Year Time Horizon)|Critical volume: 121 cu cm/mole|Dipole moment: 1.98 D|Hydroxyl radical reaction rate constant = 1.10X10-14 cu cm/molec-sec at 25 °C

Highly flammable. Insoluble in water. Easily ignited by heat, sparks or flames. Forms explosive mixtures with air

Fluorinated Organic Compounds

Highly Flammable

DIFLUOROMETHANE can react with some metals to form dangerous products. May react violently with aluminum. Incompatible with strong oxidizing and reducing agents. Also incompatible with many amines, nitrides, azo/diazo compounds, alkali metals, and epoxides.

Critical temperature: 351.28 K; critical pressure: 5.79 MPa

2.1

UN 3252 2.1

1

11-12

9-16-33

PA8537500

F,F+

Flammable

Stable at normal temperatures and pressure.

P210, P261, P271, P304+P340, P312, P377, P381, P403, P403+P233, P405, P410+P403, P501

H220

SRP: Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

Danish EPA; Survey of selected fluorinated green-house gases (2015)[Available from, as of March 3, 2016: http://eng.mst.dk/]

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]: EXTREMELY FLAMMABLE. Will be easily ignited by heat, sparks or flames. Will form explosive mixtures with air. Vapors from liquefied gas are initially heavier than air and spread along ground. CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966) and Methane (UN1971) are lighter than air and will rise. Hydrogen and Deuterium fires are difficult to detect since they burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.) Vapors may travel to source of ignition and flash back. Cylinders exposed to fire may vent and release flammable gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket. (ERG, 2016)

|Danger|H220 (76.52%): Extremely flammable gas [Danger Flammable gases]|P210, P377, P381, P403, and P410+P403|Aggregated GHS information provided by 247 companies from 7 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H220: Extremely flammable gas [Danger Flammable gases]|P210, P261, P271, P304+P340, P312, P377, P381, P403, P403+P233, P405, P410+P403, and P501

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]: As an immediate precautionary measure, isolate spill or leak area for at least 100 meters (330 feet) in all directions. LARGE SPILL: Consider initial downwind evacuation for at least 800 meters (1/2 mile). FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 1600 meters (1 mile) in all directions; also, consider initial evacuation for 1600 meters (1 mile) in all directions. In fires involving Liquefied Petroleum Gases (LPG) (UN1075); Butane, (UN1011); Butylene, (UN1012); Isobutylene, (UN1055); Propylene, (UN1077); Isobutane, (UN1969); and Propane, (UN1978), also refer to BLEVE - SAFETY PRECAUTIONS (ERG page 368). (ERG, 2016)

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]: ELIMINATE all ignition sources (no smoking, flares, sparks or flames in immediate area). All equipment used when handling the product must be grounded. Do not touch or walk through spilled material. Stop leak if you can do it without risk. If possible, turn leaking containers so that gas escapes rather than liquid. Use water spray to reduce vapors or divert vapor cloud drift. Avoid allowing water runoff to contact spilled material. Do not direct water at spill or source of leak. Prevent spreading of vapors through sewers, ventilation systems and confined areas. Isolate area until gas has dispersed. CAUTION: When in contact with refrigerated/cryogenic liquids, many materials become brittle and are likely to break without warning. (ERG, 2016)

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection. Always wear thermal protective clothing when handling refrigerated/cryogenic liquids. (ERG, 2016)|Wear positive pressure self-contained breathing apparatus. Wear appropriate chemical protective clothing.

Difluoromethane is a flammable gas.

If material on fire or involved in fire: Do not extinguish fire unless flow can be stopped. Use water in flooding quantities as fog. Cool all affected containers with flooding quantities of water. Apply water from as far a distance as possible. ... If fire becomes uncontrollable or container is exposed to direct flame-- consider evacuation of one-half (1/2) mile radius.

If material not on fire and not involved in fire: Keep sparks, flames, an other sources of ignition away. Keep material out of water sources and sewers. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors.|Personnel protection: Avoid breathing vapors. Keep upwind. ... Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water. Approach fire with caution.|If material leaking (not on fire) consider evacuation from downwind area based on amount of material spilled, location and weather conditions.

/GUIDE 115 GASES - FLAMMABLE (Including Refrigerated Liquids)/ Fire or Explosion: EXTREMELY FLAMMABLE. Will be easily ignited by heat, sparks or flames. Will form explosive mixtures with air. Vapors from liquefied gas are initially heavier than air and spread along ground. CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966) and Methane (UN1971) are lighter than air and will rise. Hydrogen and Deuterium fires are difficult to detect since they burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.) Vapors may travel to source of ignition and flash back. Cylinders exposed to fire may vent and release flammable gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket.|/GUIDE 115 GASES - FLAMMABLE (Including Refrigerated Liquids)/ Health: Vapors may cause dizziness or asphyxiation without warning. Some may be irritating if inhaled at high concentrations. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire may produce irritating and/or toxic gases.|/GUIDE 115 GASES - FLAMMABLE (Including Refrigerated Liquids)/ Public Safety: CALL Emergency Response Telephone Number on Shipping Paper first. If Shipping Paper not available or no answer, refer to appropriate telephone number listed on the inside back cover. As an immediate precautionary measure, isolate spill or leak area for at least 100 meters (330 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Many gases are heavier than air and will spread along ground and collect in low or confined areas (sewers, basements, tanks). Keep out of low areas.|/GUIDE 115 GASES - FLAMMABLE (Including Refrigerated Liquids)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection. Always wear thermal protective clothing when handling refrigerated/cryogenic liquids.|For more DOT Emergency Guidelines (Complete) data for Difluoromethane (8 total), please visit the HSDB record page.

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./|The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials. Difluoromethane is included on the dangerous goods list.|The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article. Difluoromethane is included on the dangerous goods list.

Difluoromethane was detected in stack emissions from waste incineration(1). Difluoromethane emissions increased over the period of 2005 to 2013 from 0.1 to 12 Gg/year in China(2).

IDENTIFICATION AND USE: Difluoromethane (HFC32) is a colorless gas. It is used in refrigeration, organic synthesis, and as a tracer gas in gas chromatography and photoacoustic spectroscopy. HUMAN EXPOSURE AND TOXICITY: There are no data available. ANIMAL STUDIES: Inhalation of HFC32 (up to 50,000 ppm) caused no organ-specific effects. HFC32 did not sensitize the heart to adrenaline. HFC32 is slightly maternally and developmentally toxic at 50,000 ppm in rats, but not in rabbits. No evidence of teratogenicity was noted in rats or rabbits.

Difluoromethane's production and use as a refrigerant(1), coolant(1) and a tracer gas(2) may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 22(SRC), determined from a structure estimation method(2), indicates that difluoromethane is expected to have very high mobility in soil(SRC). Volatilization of difluoromethane from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 0.29 atm-cu m/mole(SRC), using a fragment constant estimation method(2). Difluoromethane is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 12,600 mm Hg at 25 °C(3). Difluoromethane, present at 3.38 mg/L, reached 8% of its Theoretical oxygen demand in 28 days using an activated sludge inoculum in the OECD 301D test(4), indicating that biodegradation is not an important environmental fate process(SRC).|AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 22(SRC), determined from a structure estimation method(2), indicates that difluoromethane is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 0.29 atm-cu m/mole(SRC), developed using a fragment constant estimation method(2). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 2 hours and 3 days, respectively(SRC). Difluoromethane is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). According to a classification scheme(4), an estimated BCF of 3(SRC), from its log Kow of 0.20(5) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Difluoromethane, present at 3.38 mg/L, reached 8% of its Theoretical oxygen demand in 28 days using an activated sludge inoculum in the OECD 301D screening test(6).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), difluoromethane, which has a vapor pressure of 12,600 mm Hg at 25 °C(2), is expected to exist solely as a gas in the ambient atmosphere. Gas-phase difluoromethane is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 4 years(SRC), calculated from the preferred rate constant value of 1.1X10-14 cu cm/molecule-sec(3). The reaction of difluoromethane with hydroxyl radicals will form carbonyl difluoride(4). Atmospheric life-times for difluoromethane have been reported as 5.28-7.3 years(4-8). Difluoromethane has estimated 20-, 100- and 500-year Global Warming Potentials of 1800-2920, 550-889 and 180-276, respectively(4-7). Difluoromethane does not contain chromophores that absorb at wavelengths >290 nm(9) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

The rate constant for the vapor-phase reaction of difluoromethane with photochemically-produced hydroxyl radicals has been reported as 2.52X10-15 to 9.5X10-13 cu cm/molecule-sec, the preferred value is 1.1X10-14 cu cm/molecule-sec(1-2). This corresponds to an atmospheric half-life of about 4 years at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(3). The reaction of difluoromethane with hydroxyl radicals will form carbonyl difluoride(4). Atmospheric life-times for difluoromethane have been reported as 5.28-7.3 years(4-8). Difluoromethane has estimated 20, 100 and 500 year Global Warming Potentials of 1800-2920, 550-889 and 180-276, respectively(4-7). Difluoromethane does not contain chromophores that absorb at wavelengths >290 nm(9) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC). Difluoromethane is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(9).

An estimated BCF of 3 was calculated in fish for difluoromethane(SRC), using a log Kow of 0.20(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of difluoromethane can be estimated to be 22(SRC). According to a classification scheme(2), this estimated Koc value suggests that difluoromethane is expected to have very high mobility in soil.

The Henry's Law constant for difluoromethane is estimated as 0.29 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that difluoromethane is expected to volatilize rapidly from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 2 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 3 days(SRC). Difluoromethane's Henry's Law constant indicates that volatilization from moist soil surfaces will occur(SRC). Difluoromethane is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 12,600 mm Hg(3).

According to the 2012 TSCA Inventory Update Reporting data, five reporting facilities estimate the number of persons reasonably likely to be exposed in the manufacturing, processing, or use of difluoromethane in the United States may be as low as <10 workers up to the range of 100-499 workers per plant; the data may be greatly underestimated due to confidential business information (CBI) or unknown values(1).|Occupational exposure to difluoromethane may occur through inhalation and dermal contact with this compound at workplaces where difluoromethane is produced or used. With increasing emissions of difluoromethane, the general population may be exposed via inhalation of ambient air. (SRC)

Difluoromethane (HFC32) is under development as a replacement for chlorofluorocarbons (CFCs) in some refrigeration applications. It has been evaluated by standard studies of toxicity, developmental toxicity, and genotoxicity. In addition, the metabolism and disposition of HFC32 was investigated and a physiologically based pharmacokinetic (PB-PK) model constructed /using rats and rabbits/. ... The pharmacokinetics of [(14)C]difluoromethane (10,000 to 50,000 ppm/6 hr) revealed that about 2.1% of the inhaled HFC32 was absorbed and that steady state blood levels were achieved within 2 hr and were proportional to dose. Carbon dioxide was the major metabolite of HFC32 at all exposure levels. Carbon monoxide was not detected. The in vivo data were used to validate a PB-PK model to describe the uptake and metabolism of HFC32. Absorption and distribution are adequately described using rat blood:air and tissue:air partition coefficients. Metabolism, which was linear across the dose range, was described by a first order rate constant (Kf = 8.98 hr-1). Of the absorbed HFC32, about 63% was metabolized at all doses; however, when metabolism was expressed as a percentage of the inhaled dose it was much lower, being about 1.4% of the HFC32 entering the airways. ...|Difluoromethane (HFC32) is under development as a replacement for chlorofluorocarbons (CFCs) in some refrigeration applications. The metabolism and disposition of [(14)C]-difluoromethane ([(14)C]-HFC32) was determined in male Swiss mice as a consequence of a single 6 hr inhalation exposure to atmospheres of 10,000 ppm. Of the inhaled dose, about 1-2% was recovered in expired air, urine, feces and carcass suggesting that systemic absorption of this hydrofluorocarbon from the alveolar air space of the lung into blood is poor. Upon cessation of exposure the majority of the systemically absorbed HFC32 was exhaled within 1 hr. Carbon dioxide was a major metabolite of HFC32. Carbon dioxide measured post-exposure accounted for about 0.3% of the inhaled dose. Urinary and fecal excretion of non-volatile metabolites accounted for about 0.34% and 0.07% of the inhaled dose, respectively. Carbon monoxide could not be detected. Total metabolism, measured as the sum of the radioactivity recovered in urine, feces, as carbon dioxide and that retained in the carcass, amounted to about 0.8% of the inhaled dose, equivalent to 64% of the total radioactivity recovered. Analysis of a range of tissues at 4 days post-exposure showed a relatively uniform distribution of radioactivity with the highest concentration in the lung, liver and kidney. There was no evidence of a specific retention in any organ or tissue.

Difluoromethane (HFC32) is under development as a replacement for chlorofluorocarbons (CFCs) in some refrigeration applications. It has been evaluated by standard studies of toxicity, developmental toxicity, and genotoxicity. In addition, the metabolism and disposition of HFC32 was investigated and a physiologically based pharmacokinetic (PB-PK) model constructed /using rats and rabbits/. ... The pharmacokinetics of [(14)C]difluoromethane (10,000 to 50,000 ppm/6 hr) revealed that about 2.1% of the inhaled HFC32 was absorbed and that steady state blood levels were achieved within 2 hr and were proportional to dose. Carbon dioxide was the major metabolite of HFC32 at all exposure levels. Carbon monoxide was not detected. The in vivo data were used to validate a PB-PK model to describe the uptake and metabolism of HFC32. Absorption and distribution are adequately described using rat blood:air and tissue:air partition coefficients. Metabolism, which was linear across the dose range, was described by a first order rate constant (Kf = 8.98 hr-1). Of the absorbed HFC32, about 63% was metabolized at all doses; however, when metabolism was expressed as a percentage of the inhaled dose it was much lower, being about 1.4% of the HFC32 entering the airways. ... /rat, rabbit/|Difluoromethane (HFC32) is under development as a replacement for chlorofluorocarbons (CFCs) in some refrigeration applications. The metabolism and disposition of [(14)C]-difluoromethane ([(14)C]-HFC32) was determined in male Swiss mice as a consequence of a single 6 hr inhalation exposure to atmospheres of 10 000 ppm. Of the inhaled dose, about 1-2% was recovered in expired air, urine, feces and carcass suggesting that systemic absorption of this hydrofluorocarbon from the alveolar air space of the lung into blood is poor. Upon cessation of exposure the majority of the systemically absorbed HFC32 was exhaled within 1 hr. Carbon dioxide was a major metabolite of HFC32. Carbon dioxide measured post-exposure accounted for about 0.3% of the inhaled dose. Urinary and fecal excretion of non-volatile metabolites accounted for about 0.34% and 0.07% of the inhaled dose, respectively. Carbon monoxide could not be detected. Total metabolism, measured as the sum of the radioactivity recovered in urine, feces, as carbon dioxide and that retained in the carcass, amounted to about 0.8% of the inhaled dose, equivalent to 64% of the total radioactivity recovered. Analysis of a range of tissues at 4 days post-exposure showed a relatively uniform distribution of radioactivity with the highest concentration in the lung, liver and kidney. There was no evidence of a specific retention in any organ or tissue.

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]: Vapors may cause dizziness or asphyxiation without warning. Some may be irritating if inhaled at high concentrations. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire may produce irritating and/or toxic gases. (ERG, 2016)

Excerpt from ERG Guide 115 [Gases - Flammable (Including Refrigerated Liquids)]: Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. Clothing frozen to the skin should be thawed before being removed. In case of contact with liquefied gas, thaw frosted parts with lukewarm water. In case of burns, immediately cool affected skin for as long as possible with cold water. Do not remove clothing if adhering to skin. Keep victim calm and warm. (ERG, 2016)

First aid responses: Move victim to fresh air; call emergency medical care. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. In case of frostbite, thaw frozen parts with water. Keep victim quiet and maintain normal body temperatures.|/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Chlorinated fluorocarbons (CFCs) and related compounds/|/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations as needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Minimize physical activity and provide a quiet atmosphere. Monitor for pulmonary edema and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. Rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . Treat frostbite with rapid rewarming techniques ... . /Chlorinated fluorocarbons (CFCs) and related compounds/|/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag-valve-mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Chlorinated fluorocarbons (CFCs) and related compounds/

difluoromethane

All other basic inorganic chemical manufacturing|Methane, difluoro-: ACTIVE|Hydrofluorocarbon refrigerant with zero ozone-depletion potential.

Gas chromatographic method for determining fluorocarbons in air is described. Concn in air are determined directly. /Fluorocarbons/|A gas chromatographic procedure for determining atmospheric levels of fluorocarbons is described. Column is temp programmed to separate halogenated components while maintaining short retention times for each component. Freon 113 incl. /Fluorocarbons/

Gas chromatography with electron capture analysis of the blood headspace can be used to determine the concentration of halogenated solvents in biological samples. /Halogenated Hydrocarbons-Halogenated Solvents/