1,1-Difluoroethane

66.05

66.05

200-866-1

0B1U8K2ME0

1729

1030

DTXSID0024050

Colorless gas

2903399090

0

0.75

1,1-Difluoroethane is colorless, odorless gas shipped as a liquefied gas under its vapor pressure. Contact with the liquid can cause frostbite. It is easily ignited. Its vapors are heavier than air and a flame can travel back to the source of leak very easily. This leak can be either a liquid or vapor leak. It can asphyxiate by the displacement of air. Under prolonged exposure to fire or heat the containers may rupture violently and rocket.

0.91 g/cm³ @ Temp: 21 °C

-117 °C

-24.7 °C

Flammable gas

1.3011 (-72ºC)

Solubility in water, g/100ml at 25°C: 0.02 (very poor)

Fireproof. Separated from incompatible materials. Keep in a well-ventilated room.

Vapour pressure, kPa at 20°C: 516

2.28 (vs air)

Inhalation-rat LCL0: 64000 PPM/4 hours; inhalation-mouse LC50: 977 mg/m3/2 hours

Non-combustible at normal temperature; flammable with high heat; burning produces toxic fluoride gas

vol% in air: 3.78

Odorless

3.40e-14 cm3/molecule*sec

0.02 atm-m3/mole|Henry's Law constant = 2.03X10-2 atm-cu m/mol at 25 °C

Global Warming Potential (GWP): Chemical: HFC-152a; GWP: 124 (100-Year Time Horizon)|Dipole moment = 2.27 debye|Enthalpy of Formation: 75.0 kJ/mol at 298.15 K|Critical molar volume: 178 cu cm/mol|For more Other Experimental Properties (Complete) data for 1,1-Difluoroethane (6 total), please visit the HSDB record page.

Highly flammable.

Fluorinated Organic Compounds

Highly Flammable

Halogenated aliphatic compounds, such as 1,1-DIFLUOROETHANE, are moderately or very reactive. Halogenated organics generally become less reactive as more of their hydrogen atoms are replaced with halogen atoms. Low molecular weight haloalkanes are highly flammable and can react with some metals to form dangerous products. Materials in this group are incompatible with strong oxidizing and reducing agents. Also, they are incompatible with many amines, nitrides, azo/diazo compounds, alkali metals, and epoxides. The reaction of aluminum with various halogenated hydrocarbons produces a self-sustaining reaction with sufficient heat to melt aluminum pieces, examples of other halogenated hydrocarbons are fluorotrichloromethane, dichlorodifluoromethane, chlorodifluoromethane, tetrafluoromethane. The vigor of the reaction appears to be dependent on the combined degree of fluorination and the vapor pressure [Chem. Eng. News 39(27):44(1961)].

455 °C

-7,950 Btu/lb = -4,420 cal/g = -185X10+5 J/kg

Flammable limits in air 3.7-18%.|Lower flammable limit: 3.9% by volume; Upper flammable limit: 16.9% by volume

The gas mixes well with air, explosive mixtures are easily formed. As a result of flow, agitation, etc., electrostatic charges can be generated.

19.08 kJ/mol ar 25 °C

Critical temperature: 3896.4 K; Critical pressure: 4.52 MPa

2.1

UN 1030 2.1

1

11-12

16-33-36-38

KI1410000

F,F+

The warehouse is ventilated, low temperature and dry; lightly loaded and unloaded; stored separately from flammable materials

Flammable

High heat and explosive

Stable under recommended storage conditions.

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.|Product: Burn in a chemical incinerator equipped with an afterburner and scrubber but exert extra care in igniting as this material is highly flammable. Offer surplus and non-recyclable solutions to a licensed disposal company. Contact a licensed professional waste disposal service to dispose of this material; Contaminated packaging: Dispose of as unused product.

Incompatible materials: Alkali metals, Alkaline earth metals, Powdered metals, Powdered metal salts|Reacts with amines, reducing agents, strong oxidants, and epoxides.|Reaction with the lighter divalent metals may give much more reactive materials analogous to Grignard reagents. /Haloalkanes/

Danish EPA; Survey of selected fluorinated green-house gases (2015)[Available from, as of March 3, 2016: http://eng.mst.dk/]|Organization for Economic Cooperation and Development; Screening Information Data Set for 1,1-Difluoroethane (HFC-152a), 75-37-6 p.14 (June 2006). This OECD Initial Assessment of HPV Chemicals is part of a series of OECD SIDS documents published by UNEP Chemicals to facilitate the access to information needed for health and environmental risk assessments of chemicals.[Available from the Database Query page, as of March 1, 2016: http://www.chem.unep.ch/irptc/sids/OECDSIDS/sidspub.html]

Special Hazards of Combustion Products: Irritating hydrogen fluoride fumes may form in fire. Behavior in Fire: Containers may explode. Vapors are heavier than air and may travel a considerable distance to an ignition source and flash back. (USCG, 1999)|Extremely flammable. Gives off irritating or toxic fumes (or gases) in a fire. Gas/air mixtures are explosive.|Flammable - 4th degree

|Danger|H220 (95.64%): Extremely flammable gas [Danger Flammable gases]|P210, P377, P381, P403, and P410+P403|Aggregated GHS information provided by 601 companies from 17 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)

Individual breathing devices with air supply; neoprene gloves; protective clothing; eye protection (USCG, 1999)|Eye/face protection: Face shield and safety glasses. Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).|Skin protection: Handle with gloves.|Body Protection: Impervious clothing. Flame retardant antistatic protective clothing. The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.|Respiratory protection: Where risk assessment shows air-purifying respirators are appropriate use a full-face respirator with multipurpose combination (US) or type AXBEK (EN 14387) respirator cartridges as a backup to engineering controls. If the respirator is the sole means of protection, use a full-face supplied air respirator. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).|Wear appropriate chemical protective gloves and goggles.

A very dangerous fire hazard when exposed to heat or flame; can react vigorously with oxidizing materials.

Explosive limits, vol% in air: 3.7-18|Explosive limits , vol% in air: 3.7-18

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.|Advice for firefighters: Wear self-contained breathing apparatus for firefighting if necessary.|Use water spray to cool unopened containers.|If material on fire or involved in fire: Do not extinquish fire unless flow can be stopped. Use water in flooding quantities as fog. Cool all affected containers with flooding quantitites of water. Apply water from as far a distance as possible.|For more Fire Fighting Procedures (Complete) data for 1,1-Difluoroethane (7 total), please visit the HSDB record page.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Remove all sources of ignition. Evacuate personnel to safe areas. Beware of vapors accumulating to form explosive concentrations. Vapors can accumulate in low areas; Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains; Methods and materials for containment and cleaning up: Clean up promptly by sweeping or vacuum.|Evacuate danger area! Consult an expert! Ventilation. Remove all ignition sources ... Remove vapor with fine water spray. NEVER direct water jet on liquid.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Remove all sources of ignition. Evacuate personnel to safe areas. Beware of vapors accumulating to form explosive concentrations. Vapors can accumulate in low areas; Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains.|Precautions for safe handling: Avoid inhalation of vapor or mist. Use explosion-proof equipment. Keep away from sources of ignition - No smoking. Take measures to prevent the build up of electrostatic charge.|Appropriate engineering controls: Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday.|Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.|For more Preventive Measures (Complete) data for 1,1-Difluoroethane (8 total), please visit the HSDB record page.

/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 1,1-Difluoroethane (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. 1,1-Difluoroethane 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. 1,1-Difluoroethane is included on the dangerous goods list.

Remove all ignition sources. Evacuate danger area! Consult an expert! Personal protection: chemical protection suit including self-contained breathing apparatus. Ventilation. Remove vapour with fine water spray. NEVER direct water jet on liquid.

Fireproof. Separated from incompatible materials. Keep in a well-ventilated room.

On loss of containment this substance can cause suffocation by lowering the oxygen content of the air in confined areas.

Rapid evaporation of the liquid may cause frostbite. The substance may cause effects on the cardiovascular system. This may result in cardiac disorders. Exposure at high levels could cause unconsciousness.

NO open flames, NO sparks and NO smoking. Closed system, ventilation, explosion-proof electrical equipment and lighting. Prevent build-up of electrostatic charges (e.g., by grounding). Use non-sparking handtools.

Use ventilation.

Cold-insulating gloves.

Wear safety goggles or eye protection in combination with breathing protection.

This action promulgates standards of performance for equipment leaks of Volatile Organic Compounds (VOC) in the Synthetic Organic Chemical Manufacturing Industry (SOCMI). The intended effect of these standards is to require all newly constructed, modified, and reconstructed SOCMI process units to use the best demonstrated system of continuous emission reduction for equipment leaks of VOC, considering costs, non air quality health and environmental impact and energy requirements. Difluoroethane is produced, as an intermediate or final product, by process units covered under this subpart.

The major hazards encountered in the use and handling of freon 152A stem from its toxicologic properties and flammability. Toxic by inhalation and dermal contact, exposure to this colorless, odorless gas may occur from its use as a refrigerant, aerosol propellant, and intermediate. Effects from exposure may include light-headedness, irritation of the eyes, nose, and throat, frostbite, pulmonary edema, palpitations, ventricular fibrillation, and sudden death. In activities where overexposure may occur, wear a self-contained breathing apparatus and personal protective clothing. Freon 152A is extremely flammable and may be ignited by heat, sparks, or flames in a wide range of concentrations (flammable limits: 3.7%-18%. Freon 152A is an explosion hazard in confined spaces such as sewers, and its heavier than air vapor may travel to a source of ignition and flash back. Also, containers (cyllinders) of freon 152A may explode in the heat of a fire, and the burning substance may produce irritating or poisonous fumes such as hydrogen fluoride or phosgene. For fires involving freon 152A, consider evacuation for a 1/2 mile radius. Let tank cars, tank trucks or storage tanks burn unless the leak can be stopped. For smaller fires, extinguish with dry chemical, CO2, Halon, water spray or fog. For massive fires, use unmanned hose holders. Shipment of freon 152A is forbidden on passenger carrying aircraft and railcars. Any shippment of freon 152A should be done in containers bearing the label, "Flammable gas", and storage should be in areas away from sparks, flames, or other sources of ignition. Should a leak occur, isolate the area, use water spray to kock down vapor, and attempt to stop the leak if possible without undue personal risk. Do not allow the material to enter water sources or sewers. Before implementing land disposal of waste freon 152A, consult with environmental regulatory agencies for guidance.

1,1-Difluoroethane was detected at a rate of 4 kilo tons CO2 equivalents/year in the effluent from an HFC packaging plant in The Netherlands, sampled in 1990(1).

1,1-Difluoroethane is listed as an ingredient in over 160 household products including: auto, commercial/institutional, home maintenance, inside the home, personal care and pesticide products(1).

practically nontoxic

IDENTIFICATION AND USE: 1,1-Difluoroethane (HFC-152a) is a colorless, odorless gas. The primary uses for HFC-152a are as an aerosol propellant and a foam expansion agent. Other potential uses include refrigeration blends and catalyst regeneration. Intermediate to vinyl fluoride. HUMAN EXPOSURE AND TOXICITY: Several volunteers were exposed to 500,000 ppm of HFC 152a for several min. Analgesia and an impending loss of consciousness were reported. Rapid evaporation of the liquid may cause frostbite. The substance may cause effects on the cardiovascular system , resulting in cardiac disorders. Abuse of fluorinated hydrocarbons is on the rise, especially among the adolescent population. Inhaling aerosolized computer-cleaning spray composed of HFC-152a led to marked upper and lower lip facial swelling consistent with angioedema. The patient also had a prolonged QT interval, mild inspiratory stridor, but no urticaria. In other case, acute myocardial injury and global hypokinesis along with rhabdomyolysis, acute kidney injury, and fulminant hepatitis developed after 2 days of nearly continuous huffing. A serious but rarely reported complication of halogenated hydrocarbon inhalation abuse is severe mucosal frostbite. HFC-152a showed evidence of weak clastogenicity in an in vitro human lymphocyte chromosome aberration test. ANIMAL STUDIES: HFC-152a has low acute inhalation toxicity. The repeat dose studies show some potential for irritation. HFC-152a has the potential to produce cardiac sensitization in dogs challenged simultaneously with high exposure concentrations and high doses of exogenous epinephrine. HFC-152a had anesthetic properties at a 100,000 ppm exposure level during a 2-week repeated dose inhalation study in rats. No adverse effects were observed in rats following a 3-month inhalation exposure to 25,000 ppm HFC-152a. In a developmental study, female rats were exposed via inhalation up to 50,000 ppm during days 6 to 15 of pregnancy for 6 hours per day. No compound related maternal and developmental effects were observed at any of the concentrations tested. No histopathological or weight effects on reproductive organs were observed in male and female rats exposed up to 25,000 ppm HFC-152a for 6 hours per day, 5 days per week for 3, 12 or 24 months. . In a 2-year bioassay, HFC-152a was not carcinogenic to rats at inhalation exposure levels up to 25,000 ppm. HFC-152a was not mutagenic in the in vitro bacterial reverse mutation test (Ames test) in Salmonella typhimurium and Escherichia coli strains. An in vivo rat Micronucleus Test did not show any evidence of chromosome damage or bone marrow cell toxicity when administered by whole body inhalation.

LC50 Mouse inhalation 369,000 ppm/ 2 hr

1,1-Difluoroethane's production and use as a refrigerant(1) and synthesis intermediate for 1-chloro-1,1-difluoroethane (R-142b)(2) may result in its release to the environment through various waste streams(SRC). Its use as a foaming agent(1) and aerosol propellant(2) will result in its direct release to the environment(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 32(SRC), determined from a structure estimation method(2), indicates that 1,1-difluoroethane is expected to have very high mobility in soil(SRC). Volatilization of 1,1-difluoroethane from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 0.0203 atm-cu m/mole(3). 1,1-Difluoroethane is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 4550 mm Hg at 25 °C(4). Biodegradation data in soil were not available(SRC, 2016).|AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 32(SRC), determined from a structure estimation method(2), indicates that 1,1-difluoroethane is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon a Henry's Law constant of 0.0203 atm-cu m/mole(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 2.4 hours and 3.2 days, respectively(SRC). 1,1-Difluoroethane 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(5), an estimated BCF of 3(SRC), from its log Kow of 0.75(6) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation data in water were not available(SRC, 2016).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 1,1-difluoroethane, which has a vapor pressure of 4550 mm Hg at 25 °C(2), is expected to exist solely as a gas in the ambient atmosphere. Gas-phase 1,1-difluoroethane 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 190-270 days(SRC), calculated from rate constants of 2.54X10-14 to 3.6X10-14 cu cm/molecule-sec at 25 °C(3-5). 1,1-Difluoroethane does not contain chromophores that absorb at wavelengths >290 nm(6) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC). 1,1-Difluoroethane's atmospheric life-time has been calculated as 1.5 years with a degradation product of carbonic difluoride(7).

The rate constant for the vapor-phase reaction of 1,1-difluoroethane with photochemically-produced hydroxyl radicals has been reported as 2.54X10-14 to 3.6X10-14 cu cm/molecule-sec at 25 °C(1-3). This corresponds to an atmospheric half-life of about 190-270 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(4). 1,1-Difluoroethane has reported 20 and 100 Year Global Warming Potential of 3.3 and 0.9, respectively(5). 1,1-Difluoroethane is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(6). 1,1-Difluoroethane does not contain chromophores that absorb at wavelengths >290 nm(6) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC). 1,1-Difluoroethane's atmospheric life-time has been calculated as 1.5 years with a degradation product of carbonic difluoride(7).

An estimated BCF of 3 was calculated in fish for 1,1-difluoroethane(SRC), using a log Kow of 0.75(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 1,1-difluoroethane can be estimated to be 32(SRC). According to a classification scheme(2), this estimated Koc value suggests that 1,1-difluoroethane is expected to have very high mobility in soil.

The Henry's Law constant for 1,1-difluoroethane is reported as 0.0203 atm-cu m/mole(1). This Henry's Law constant indicates that 1,1-difluoroethane 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 2.4 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 3.2 days(SRC). 1,1-Difluoroethane's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). 1,1-Difluoroethane is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 4550 mm Hg(3).

According to the 2012 TSCA Inventory Update Reporting data, 6 reporting facilities estimate the number of persons reasonably likely to be exposed in the manufacturing, processing, or use of 1,1-difluoroethane in the United States may be as low as <10 workers up to the range of 500-999 workers per plant; the data may be greatly underestimated due to confidential business information (CBI) or unknown values(1).|NIOSH (NOES Survey 1981-1983) has statistically estimated that 132,833 workers (116,164 of these are female) were potentially exposed to 1,1-difluoroethane in the US(1). Occupational exposure to 1,1-difluoroethane may occur through inhalation and dermal contact with this compound at workplaces where 1,1-difluoroethane is produced or used(SRC).

1,1-Difluoroethane concentrations in blood and exhaled air of healthy volunteers after 8-hour simulated exposure decreased rapidly(1). After three cases of death, blood, urine and gastric contents samples were found to contain 1,1-difluoroethane at 99.2-136.2 mg/L, 94.5-191.9 mg/L and 3.6-18.4 mg, respectively(2).

1,1-Difluoroethane (DFE) is a halogenated hydrocarbon used as a propellant in products designed for dusting electronic equipment and air brush painting. When abused, inhaled DFE produces intoxication and loss of muscular coordination. To investigate DFE toxicokinetics, groups (n = 3) of Sprague-Dawley rats were exposed to 30 s of 20 L/min DFE. The experimental model was designed to mimic exposure during abuse, a protocol which has not been conducted. Tissue collection (blood, brain, heart, liver, and kidney) occurred at 0, 10, 20, 30, 45, 60, 120, 240, 480, and 900 s. Average peak DFE levels were blood 352, brain 519, heart 338, liver 187, and kidney 364 mg/L or mg/kg. The total percent uptake of the administered dose was 4.0%. Uptake into individual compartments was 2.72, 0.38, 0.15, 0.41, and 0.32% for blood, brain, heart, liver, and kidney, respectively. All animals showed signs of intoxication within 20 s manifested as lethargy, prostration and loss of righting reflex. Marked intoxication continued for about 4 min when DFE averaged 21 mg/L in blood and 17 mg/kg in brain. Between 4 and 8 min, animals continued to show signs of sedation as evidenced by reduced aggression and excitement during handling. No discernable intoxication was evident after 8 min and blood and brain levels had fallen to 10 and 6 mg/L or kg, respectively. Plots of concentration (log) versus time were consistent with a two compartment model. Initial distribution was rapid with average half life (t((1/2))) during the alpha phase of 9 s for blood, 18 s for brain and 27 s in cardiac tissue. During beta slope elimination average t((1/2)) was 86 s in blood, 110 s in brain and 168 s in heart. Late elimination half lives were longer with blood gamma = 240 s, brain gamma = 340 s, and heart gamma = 231 s. Following acute exposure the Vd = 0.06 L, beta = 0.48 min(-1), AUC = 409.8 mg.min L(-1), and CL from blood was 0.03 L min(-1). The calculated toxicokinetic data may underestimate these parameters if DFE is abused chronically due to continued uptake into lowly perfused tissues with repeated dosing.|The aim of this study was to determine the toxicokinetics of inhaled 1,1-difluoroethane (HFC-152a) in humans. Healthy volunteers were exposed to 0, 200 or 1000 ppm 1,1-difluoroethane for 2 hr at light exercise in an exposure chamber. Capillary blood, urine and exhaled air were sampled up to 22 hr post-exposure and analyzed for 1,1-difluoroethane. Fluoride and other potential metabolites were analyzed in urine. Symptoms of irritation and central nervous system effects were rated and inflammatory markers were analyzed in blood. Within a few minutes of exposure to 200 and 1000 ppm, 1,1-difluoroethane increased rapidly in blood and reached average levels of 7.4 and 34.3 uM, respectively. The post-exposure decreases in blood were fast and parallel to those in exhaled air. The observed time courses in blood and breath agreed well with those obtained with the PBPK model. The PBPK simulations indicate a net uptake during exposure to 1000 ppm of 6.6 mmol (6.7%) which corresponds to the amount exhaled post-exposure. About 20 umol excess fluoride (0.013% of inhaled 1,1-difluoroethane on a molar basis) was excreted in urine after exposure to 1000 ppm, compared to control. No fluorine-containing metabolites were detected in urine. Symptom ratings and changes in inflammatory markers revealed no exposure-related effects.

... To investigate DFE toxicokinetics, groups (n = 3) of Sprague-Dawley rats were exposed to 30 s of 20 L/min DFE. ... Plots of concentration (log) versus time were consistent with a two compartment model. Initial distribution was rapid with average half life (t((1/2))) during the alpha phase of 9 s for blood, 18 s for brain and 27 s in cardiac tissue. During beta slope elimination average t((1/2)) was 86 s in blood, 110 s in brain and 168 s in heart. Late elimination half lives were longer with blood gamma = 240 s, brain gamma = 340 s, and heart gamma = 231 s. ...

Typical impurities in HFC-152a include low level (ppm) water, low level (ppb) residual HCl and/or HF acids.

Inhalation of concentrated gas will cause suffocation. Contact with liquid can damage eyes because of low temperature. Frostbite may result from contact with liquid. (USCG, 1999)

INHALATION: remove to fresh air; use artificial respiration if necessary. EYES: get medical attention if liquid has entered eyes. SKIN: soak in lukewarm water (for frostbite). (USCG, 1999)

Fresh air, rest.

ON FROSTBITE: rinse with plenty of water, do NOT remove clothes. Refer for medical attention .

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

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 if 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/|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/|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 TKO /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 (Valium) or lorazepam (Ativan) ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Chlorinated fluorocarbons (CFCs) and related compounds/|Emergency and supportive measures: Remove the individual from the contaminated environment. Maintain an open airway and assist ventilation if necessary. Treat coma and arrhythmias if they occur. Avoid epinephrine or other sympathomimetic amines that may precipitate ventricular arrhythmias. Tachyarrhythmias caused by increased myocardial sensitivity may be treated with propranolol ... , or esmolol ... . Monitor the ECG for 4-6 hours. /Freons and Halons/|Decontamination: Inhalation: Remove victim from exposure and give supplemental oxygen if available. Ingestion: Do not give charcoal or induce vomiting because freons are rapidly absorbed and there is risk of abrupt onset of CNS depression. Consider gastric lavage (or simply aspirate liquid from stomach) if the ingestion was very large and recent (<30-45 minutes). The efficacy of activated charcoal is unknown. /Freons and Halons/

/HUMAN EXPOSURE STUDIES/ ... Healthy volunteers were exposed to 0, 200 or 1000 ppm 1,1-difluoroethane for 2 hr at light exercise in an exposure chamber. ... Symptom ratings and changes in inflammatory markers revealed no exposure-related effects.|/HUMAN EXPOSURE STUDIES/ Several volunteers were exposed to 500,000 ppm of HFC 152a for several min. Good analgesia and an impending loss of consciousness were reported.|/SIGNS AND SYMPTOMS/ Rapid evaporation of the liquid may cause frostbite. The substance may cause effects on the cardiovascular system, resulting in cardiac disorders [SRP: CARDIAC SENSITIZATION]. Exposure at high levels may result in unconsciousness.|/CASE REPORTS/ Heterotopic ossification (HO) is the formation of mature, lamellar bone within soft tissues other than the periosteum. There are three recognized etiologies of HO: traumatic, neurogenic, and genetic. Presently, there are no definitively documented causal factors of HO. The following factors are presumed to place a patient at higher risk: 60 years of age or older, male, previous HO, hypertrophic osteoarthritis, ankylosing spondylitis, diffuse idiopathic skeletal hyperostosis, prior hip surgery, and surgical risk factors. A 33-year-old male, involved in a motor vehicle crash, sustained an irreducible acetabulum fracture/dislocation, displaced proximal humerus fracture, and an impacted pilon fracture. During the time of injury, he was intoxicated from inhaling the aerosol propellant used in "dust spray" cans (1,1-difluoroethane, C2H4F2). Radiographs identified rapid pathologic bone formation about the proximal humeral metaphysis, proximal femur, elbow, and soft tissue several months following the initial injury. The patient did not have any genetic disorders that could have attributed to the bone formation but had some risk factors (male, fracture with dislocation). Surgically, the recommended precautions were followed to decrease the chance of HO. Although the patient did not have neurogenic injuries, the difluoroethane in dusting spray can cause damage to the central nervous system. Signals may have been mixed causing the patient's body to produce bone instead of tissue to strengthen the injured area. What is unusual in this case is the rate at which the pathological bone formation appeared, which was long outside the 4-6 week window in which HO starts to appear. The authors are not certain as to the cause of this rapid formation but suspect that the patient's continued abuse of inhaled aerosol propellants may be the culprit.|For more Human Toxicity Excerpts (Complete) data for 1,1-Difluoroethane (16 total), please visit the HSDB record page.

1,1-difluoroethane

The substance can be absorbed into the body by inhalation.

Dizziness. Drowsiness. Unconsciousness. Suffocation.

ON CONTACT WITH LIQUID: FROSTBITE.

See Skin.

Refrigerants, 39%; foam blowing agents, 17%; solvents, 14%; fluoropolymers, 14%; sterilant gas, 2%; aerosol propellants, 2%; food freezant, 1%; other, 8%; exports, 3% (1985) /Fluorocarbons/|Approximately 80% of HFC-152a is used as an aerosol propellant and approximately 15% is used as a foam expansion agent. The remaining 5% of the HFC-152a is for other potential uses, which include refrigeration blends and catalyst regeneration.

Technical, 98%|The concentration of 1,1-difluoroethane as a propellant in pesticide formulations ranges from 14% to 78% by weight in the pesticide formulation.|AF 152a|Algofrene Type 67|For more Formulations/Preparations (Complete) data for 1,1-Difluoroethane (13 total), please visit the HSDB record page.

Aerosol manufacturing|Ethane, 1,1-difluoro-: ACTIVE|The direct fluorination of hydrocarbon with elemental fluoride is extremely exothermic and difficult to control. ... The disadvantages of direct fluorination have been overcome by the use of fluorine carriers, in particular, high valence metal fluorides such as cobalt trifluoride, CoF3, or potassium tetrafluorocobalate, KCoF4.

This paper describes a method for the quantitation of DFE using a gas chromatography-flame-ionization headspace technique that employs solventless standards for calibration. Two calibration curves using 0.5 mL whole blood calibrators which ranged from A: 0.225-1.350 to B: 9.0-180.0 mg/L were developed. These were evaluated for linearity (0.9992 and 0.9995), limit of detection of 0.018 mg/L, limit of quantitation of 0.099 mg/L (recovery 111.9%, CV 9.92%), and upper limit of linearity of 27,000.0 mg/L. Combined curve recovery results of a 98.0 mg/L DFE control that was prepared using an alternate technique was 102.2% with CV of 3.09%. No matrix interference was observed in DFE enriched blood, urine or brain specimens nor did analysis of variance detect any significant differences (alpha = 0.01) in the area under the curve of blood, urine or brain specimens at three identical DFE concentrations. The method is suitable for use in forensic laboratories because validation was performed on instrumentation routinely used in forensic labs and due to the ease with which the calibration range can be adjusted. Perhaps more importantly it is also useful for research oriented studies because the removal of solvent from standard preparation eliminates the possibility for solvent induced changes to the gas/liquid partitioning of DFE or chromatographic interference due to the presence of solvent in specimens.|A readily constructed, automated purging assembly, on column trapping and simultaneous use of flame ionization and electrolytic conductivity detectors were applied to develop a dynamic headspace gas chromatographic technique which was evaluated for the determination of 42 organic pollutants in water, one of which was difluoroethane.

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/|Intentional abuse of 1,1-difluoroethane has been reported to cause transient symptoms such as confusion, tremors, pulmonary irritation, loss of consciousness and, rarely, coma. In the last five years, 17 cases from the San Diego County Medical Examiner's Office showed the presence of 1,1-difluoroethane in postmortem tissues, and the gas was cited in the cause of death in 13 of those cases. Detected during routine ethanol screening,1,1-difluoroethane was evaluated for concentrations in peripheral blood, central blood and vitreous humor by a slightly modified method published by Avella et al. In many cases, death from abuse of 1,1-difluoroethane seemed to occur within minutes of intentional abuse; large concentrations (>100 mg/L) of the gas were still in the blood. It is important that forensic toxicology laboratories have routine screening procedures to detect 1,1-difluoroethane because cases exist in which evidence of use from cans may not be present in proximity to the decedent, or may be undiscovered in the debris of a motor vehicle accident. It is also important to quantify concentrations of 1,1-difluoroethane in both peripheral blood and central blood, whose ratio may be useful in interpreting how recently the use of the 1,1-difluoroethane occurred.|Various hydrofluorocarbons (HFCs) have replaced the ozone-depleting chlorofluorocarbons and hydrochlorofluorocarbons during the last decades. The objective of this study was to examine the usefulness of blood and breath for exposure biomonitoring of HFCs. We compared data on blood and exhaled air from a series of experiments where healthy volunteers were exposed to vapors of four commonly used HFCs; 1,1-difluoroethane, 1,1,1-trifluoroethane, 1,1,1,2-tetrafluoroethane, and 1,1,1,3,3-pentafluoropropane. All four HFCs had similar toxicokinetic profiles in blood with a rapid initial increase and an apparent steady-state reached within a few minutes. For all HFCs, the inhalation uptake during exposure was low (less than 6%), most of which was exhaled post-exposure. No metabolism could be detected and only minor amounts were excreted unchanged in urine. The observed time courses in blood and breath were well described by physiologically-based pharmacokinetic (PBPK) modeling. Simulations of 8-hr exposures show that the HFC levels in both blood and breath drop rapidly during the first minutes post-exposure, whereafter the decline is considerably slower and mainly reflects washout from fat tissues. We conclude that blood and exhaled air can be used for biological exposure monitoring. Samples should not be taken immediately at the end of shift but rather 20-30 min later.|A headspace gas chromatographic procedure for the identification and quantitation of difluoroethane in blood is presented ... Quantitation of difluoroethane was performed using a six-point calibration curve and an internal standard of 1-propanol. The assay is linear from 0 to 115 mg/L including a low calibrator at 4 mg/L, the limit of quantitation. Within-run coefficients of variation at mean concentrations of 13.8 mg/L and 38.5 mg/L were 5.8% and 6.8% respectively. Between-run coefficients of variation at mean concentrations of 15.9 mg/L and 45.7 mg/L were 13.4% and 9.8% respectively. Several volatile substances were tested as potential interfering compounds with propane having a retention time identical to that of difluoroethane.

Fire Hazards -> Flammable - 4th degree|Cosmetics -> Propellant