The EPA has not made a
carcinogenicity assessment as yet. However, the State of
California reviewed the carcinogenicity information.
CalEPA, using the NTP study, developed a cancer
potency estimate of 4.7E-3 per mg/kg/day and defined a No
Significance Risk Level (NSRL) of 1 50 μg/day.
Increased cancer of the uterus of female mice has been
produced by exposure to 15,000 ppm, but lower concentrations
have not been studied. Rats and mice were exposed to 0
or 15,000 ppm of ethyl chloride in an NTP 2-year study with
mixed results. Results in male rats were considered
equivocal based on a combined total of five skin tumors
versus none in the control male rats. Likewise, female rats’
results were considered equivocal because three astrocytomas
were found versus none in the female control rats. The
male mouse group had such poor survival that it was deemed
an inadequate study although combined alveolar/bronchiolar
adenomas and carcinomas were reported (10/48 versus 5/50
in the control male rats). Female mice exposed to 15,000 ppm
had clear evidence of an effect, for 43/50 mice had endometrial
uterine carcinomas versus 0/49 in the female control
mice. In addition, there was a suggestion of an increase in
combined hepatocellular adenomas and carcinomas in the
female mice (8/48 exposed versus 3/49 control). There is
clear evidence for carcinogenicity in female B6C3F1 mice
and equivocal evidence in male and female F344/N rats (high
incidence of uterine carcinomas.)
Chloroethane (also known as ethyl chloride) is a chemical compound with chemical formula C2H5Cl, and has been widely used in producing tetraethyllead, a gasoline additive. It is a colorless, flammable gas or refrigerated liquid with a faintly sweet odor.
Ethyl chloride is used in the production of ethyl cellulose, use as a solvent, refrigerant, and topical anesthetic, in the manufacture of dyes, chemicals, and pharmaceuticals, and as a medication to alleviate pain associated with insect burns and stings.
In the past, ethyl chloride was used in the production of tetraethyl lead, an anti-knock additive to leaded gasoline. Government-mandated reduction in the amount of lead additives used in gasoline in the United States and a shift to the use of unleaded gasoline has caused a drastic reduction in the amount of ethyl chloride required for the production of tetraethyl lead.
Ethyl chloride is a colorless gas or liquid
(below 12℃) with a pungent, ethereal odor and a burning
taste. Shipped as a liquefied compressed gas.
Pass ethyl chloride through absorption towers containing, successively, conc H2SO4, NaOH pellets, P2O5 on glass wool, or soda-lime, CaCl2, P2O5. Condensed it into a flask containing CaH2 and fractionally distil it. It has also been purified by illumination in the presence of bromine at 0o using a 1000W lamp, followed by washing, drying and distilling. [Beilstein 1 IV 124.]
Refrigerant, solvent, alkylating agent, starting point in the manufacture of tetraethyl lead: US 1907701 (1933).
Source and exposure
Sources of possible ethyl chloride exposure include the inhalation of contaminated air and ingestion of contaminated drinking water at very low levels. The general population can be exposed to ethyl chloride by skin contact with consumer products that contain ethyl chloride such as solvents and refrigerants. Occupational exposure by inhalation or dermal contact with ethyl chloride can occur in industries such as medical and health services; automotive dealers and service stations; wholesale trade, electric, gas, and sanitary services; machinery (except electrical) and special trade contractors; fabricated metal productions; printing and publishing; painting; rubber and plastic products; and food.?Although chemists use tests such as gas chromatography to measure ethyl chloride in blood, milk, or urine, no commonly used medical tests are available to determine whether or not a person has been exposed to ethyl chloride.
Ethyl chloride is used as a refrigerant, as asolvent, in the manufacture of tetraethyl lead,and as an alkylating agent. It is also used asa topical anesthetic.
Exposure to high levels of ethyl chloride cancause stupor, eye irritation, incoordination,abdominal cramps, anesthetic effects, cardiacarrest, and unconsciousness. No toxic effectswere noted at a concentration of 10,000 ppm.A 45-minute exposure to a 4% concentrationof ethyl chloride in air was lethal to guineapigs. A brief exposure for 5 to 10 minutes toa concentration of 10% of the gas was notfatal to the test animals but caused kidneyand liver damage. In humans narcotic effectsmay occur after a few inhalations of 5–10%concentrations of the gas. Irritant effectson the eyes, skin, and respiratory tract aremild. Skin contact with the liquid can causefrostbite due to cooling by rapid evaporation.LC50 value, inhalation (rats): 60,000 ppm/2 hr.
A gaseous compound
made by the addition of hydrogen
chloride to ethene. It is used as a refrigerant
and a local anesthetic.
Solubility in water
Soluble in ethanol, ether (U.S. EPA, 1985); miscible with chlorinated hydrocarbons such as
chloroform, carbon tetrachloride, and tetrachloroethane.
A clear colorless gas with a pungent odor. Flash point -58°F. Boiling point 54°F. Less dense than water and insoluble in water. Vapors are heavier than air. Under prolonged exposure to fire or heat the containers may rupture violently and rocket.Ethyl chloride is used as a solvent for oils,resins,and waxes. It is used in medicine and as an intermediate in synthesis.
Highly flammable, severe fire and explosion risk; flammable limits in air 3.8–15.4%. Irritant
to eyes. Questionable carcinogen.
Air & Water Reactions
Highly flammable. Insoluble in water.
Ethyl chloride is a colorless gas with an ethereal odor[1,6]. Ethyl chloride has an odor threshold of 4.2 parts per million (ppm). Ethyl chloride is slightly soluble in water.
The chemical formula for ethyl chloride is C2H5Cl, and it has a molecular weight of 64.52 g/mol[1,3]. The vapor pressure for ethyl chloride is 1,008 mm Hg at 20°C, and the log octanol/water partition; coefficient (log Kow) is 1.43; coefficient (log Kow) is 1.43.
UN1037 Ethyl chloride, Hazard Class: 2.1;
Labels: 2.1-Flammable gas. Cylinders must be transported
in a secure upright position, in a well-ventilated truck.
Protect cylinder and labels from physical damage. The
owner of the compressed gas cylinder is the only entity
allowed by federal law (49CFR) to transport and refill
them. It is a violation of transportation regulations to refill
compressed gas cylinders without the express written permission of the owner.
Reactivity with Water: No reaction; Reactivity with Common Materials: No reaction; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Not pertinent; Polymerization: Not pertinent; Inhibitor of Polymerization: Not pertinent.
Ethyl Chloride can be synthesized by treatment of ethyl alcohol with HCl, cleavage of diethylether with HCl in the presence of a catalyst (ZnCl2), chlorination of ethane or hydrochlorination of ethylene. The latter is the choice of industry. The reaction is carried out at 125 °F and 125 psi in the presence of AlCl3, which is dissolved in ethyl chloride.
Vapor causes drunkenness, anesthesia, possible lung injury. Liquid may cause frostbite on eyes and skin.
Flammable gas. Slow reaction with
water; forms hydrogen chloride gas. Contact with moisture
(water, steam) forms hydrochloric acid and/or fumes of
hydrogen chloride. May accumulate static electrical
charges, and may cause ignition of its vapors. May form
explosive mixture with air. Contact with chemically active
metals: aluminum, lithium, magnesium, sodium, potassium,
zinc may cause fire and explosions. Attacks some plastics
Ethyl chloride is used in the manufacture of tetraethyllead and as an alkylating agent in the production of ethylcellulose (which is used in paper coatings, printing inks, films, adhesives and moulded plastics), ethylhydroxyethylcellulose, and some pharmaceuticals and as a foam-blowing agent in the manufacture of polystyrene. It is used as a local anaesthetic because of its rapid cooling effect as it vaporizes. Historical and minor uses Include use in organic synthesis, as an alkylating agent in the production of aluminium alkyls and other metal alkyls and as a solvent for phosphorus, sulfur, fats, oils, resins and waxes.
Photolytic. The rate constant for the reaction of chloroethane and OH radicals in the atmosphere
at 300 K is 2.3 x 10-11 cm3/molecule?sec (Hendry and Kenley, 1979). At 296 K, a photooxidation
rate constant of 3.9 x 10-13 cm3/molecule?sec was reported (Howard and Evenson, 1976). The
estimated tropospheric lifetime is 14.6 d (Nimitz and Skaggs, 1992).
Chemical/Physical. Under laboratory conditions, chloroethane hydrolyzed to ethanol (Smith and
Dragun, 1984). An estimated hydrolysis half-life in water at 25 °C and pH 7 is 38 d, with ethanol
and HCl being the expected end-products (Mabey and Mill, 1978). Based on a measured
hydrolysis rate constant of 5.1 x 10-7 at 25 °C and pH 7, the half-life is 2.6 yr (Jeffers and Wolfe,
In air, formyl chloride is the initial photooxidation product (U.S. EPA, 1985). In the presence of
water, formyl chloride hydrolyzes to HCl and carbon monoxide (Morrison and Boyd, 1971).
Burns with a smoky, greenish flame releasing hydrogen chloride (Windholz et al., 1983).
In the laboratory, the evaporation half-life of chloroethane (1 mg/L) from water at 25 °C using a
shallow-pitch propeller stirrer at 200 rpm at an average depth of 6.5 cm was 23.1 min (Dilling,
At influent concentrations of 1.0, 0.1, and 0.01 mg/L, the GAC adsorption capacities at pH 5.3
were 0.59, 0.07, and 0.007 mg/g, respectively (Dobbs and Cohen, 1980).
with experimental carcinogenic and
neoplastigenic data. Mildly toxic by
inhalation. An irritant to sh, eyes, and mucous membranes. The liquid is harmful
to the eyes and can cause some irritation. In
the case of guinea pigs, the symptoms
attending exposure are similar to those
caused by methyl chloride, except that the
signs of lung irritation are not as
pronounced. It gives some warning of its
presence because it is irritating, but it is
possible to tolerate exposure to it until one
becomes unconscious. It is the least toxic
of all the chlorinated hydrocarbons. It can
cause narcosis, although the effects are
A very dangerous fire hazard when
exposed to heat or flame; can react
vigorously with oxidizing materials. Severe
explosion hazard when exposed to flame.
Reacts with water or steam to produce toxic
and corrosive fumes. Incompatible with
potassium. To fight fire, use carbon dioxide.
When heated to decomposition it emits
toxic fumes of phosgene and Cl-. See also
CHLOROETHANE is heat sensitive. CHLOROETHANE will hydrolyze in the presence of alkalis and water. CHLOROETHANE reacts with water or steam to produce toxic and corrosive fumes. CHLOROETHANE can also react vigorously with oxidizing materials. The vapor forms highly flammable mixtures with air. A mixture of CHLOROETHANE with potassium is shock-sensitive. Contact with chemically active metals such as Na, K, Ca, powdered Al, Zn and Mg may result in violent reactions.
Clear, colorless gas or liquid with a pungent or faint, sweetish ether-like odor. When spilled, ethyl
chloride evaporates quickly. Odor threshold concentration is 4.2 ppm (quoted, Amoore and
Return refillable compressed
gas cylinders to supplier. Incineration, preferably after mixing with another combustible fuel. Care must be exercised
to assure complete combustion to prevent the formation of
phosgene. An acid scrubber is necessary to remove the halo
Ethyl chloride is used as an ethylating
agent in the manufacture of tetraethyl lead, dyes, drugs,
and ethyl cellulose; as a pharmaceutical, solvent; alkylating
agent; as a refrigerant and as a local anesthetic (freezing).
Acute inhalation exposure to high levels of ethyl chloride in humans has resulted in temporary feelings of drunkenness, dizziness, lack of muscle coordination and unconsciousness. Accidental death has resulted from its former medical use as an anesthetic during major surgery.[1,2] Tests involving acute exposure of animals in rats and mice have shown ethyl chloride to have low toxicity from inhalation exposure.
Neurological symptoms including ataxia, tremors, speech difficulties, slowed reflexes, involuntary eye movement, and hallucinations, and liver effects were reported in individuals who purposely inhaled very high concentrations of ethyl chloride for a few months.
Some animal studies indicate effects on the lungs, liver, kidneys, and heart due to ethyl chloride exposure via inhalation. The Reference Concentration (RFC) for ethyl chloride is 10 milligrams per cubic meter (mg/m3) based on delayed fetal ossification in mice. The RFC is an estimate (with uncertainty spanning perhaps an order of magnitude) of a continuous inhalation exposure to the human population (including sensitive subgroups), which is likely to be without appreciable risk of deleterious noncancer effects during a lifetime. It is not a direct esimator of risk but rather a reference point to gauge the potential effects. At exposures increasingly greater than the RFC, the potential for adverse health effects increases. Lifetime exposure above the RFC does not imply that an adverse health effect would necessarily occur.
EPA has medium confidence in the study on which the RFC is based because, although the study is well conducted, it does not establish a firm concentration-response relationship with an adverse effect and was not performed at levels eliciting maternal toxicity; medium confidence in the database due to the lack of a multigenerational reproductive study and a developmental study in a second species; and, consequently, medium confidence in the RFC.?EPA has not established a Reference Dose (RfD) for ethyl chloride. Reproductive/Developmental Effects
No studies were located regarding reproductive or developmental effects following ethyl chloride inhalation exposure in humans.
Several animal studies found no reproductive effects caused by ethyl chloride exposure. An animal study reported a decrease in uterine weights, while another study reported minimal evidence of fetotoxicity (increase in centers of unossified bones of the skull) from inhalation exposure to ethyl chloride.
There are no human cancer data available for ethyl chloride. A 2-year bioassay performed by the NTP indicated that inhaled ethyl chloride is carcinogenic in female mice and may be carcinogenic in rats. Female mice experienced a significant increase in the incidence of uterine tumors and hepatocellular tumors, but the data on male mice were considered inadequate because of a low survival rate. Benign and malignant epithelial neoplasms of the skin, and three uncommon malignant astorcyomas of the brain, were reported in male and female rats, respectively. EPA has not classified ethyl chloride for carcinogenicity.
Chlorethane (ethyl chloride) is a highly flammable liquid that acts as a topical vapocoolant
to control pain associated with minor surgical procedures.When applied as
a spray, the product produces freezing of superficial tissues to ?20?C, which results
in insensitivity of peripheral nerve endings and local anesthesia that is maintained
up to 1 minute. Other coolant sprays can be used with the same effect.
The dominant process for production of ethyl chloride in the USA involves the addition of anhydrous hydrogen chloride to ethylene in the presence of an aluminium chloride catalyst. The hydrochlorination is a liquidphase reaction, carried out at about 40°C. Reacted products are fed into a flash evaporator column, where ethyl chloride is separated from less volatile compounds and then purified by fractionation. Hydrochlorination of ethanol has not been used for US ethyl chloride production since 1980, and chlorination of ethane (catalytically, electrolytically, thermallyor photochemically) has not been used at any production facility in the USA since 1974. Ethyl chloride is also obtained as a by-product from the production of vinyl chloride or chlorofluorocarbon, although this method accounts for only a small amount.
Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological Profile for Ethyl chloride (Update).Public Health Service, U.S. Department of Health and Human Services, Atlanta, GA. 1998.
U.S. Department of Health and Human Services. Hazardous Substances Data Bank (HSDB, online database). National Toxicology Information Program, National Library of Medicine, Bethesda, MD. 1993.
U.S. Department of Health and Human Services. Registry of Toxic Effects of Chemical Substances (RTECS, online database). National Toxicology Information Program, National Library of Medicine, Bethesda, MD. 1993.
U.S. Environmental Protection Agency. Integrated Risk Information System (IRIS) on Ethyl Chloride. National Center for Environmental Assessment, Office of Research and Development, Washington, DC. 1999.
National Toxicology Program. Toxicology and Carcinogenesis Studies of Ethyl chloride (Ethyl Chloride) (CAS No. 75-00-3) in F344/N Rats and B6C3F1 Mice (Inhalation Studies). TR No. 346. U.S. Department of Health and Human Services, Public Health Service, National Institutes of Health, Bethesda, MD. 1989.
The Merck Index. An Encyclopedia of Chemicals, Drugs, and Biologicals. 11th ed. Ed. S. Budavari. Merck and Co. Inc., Rahway, NJ. 1989.
J.E. Amoore and E. Hautala. Odor as an aid to chemical safety: Odor thresholds compared with threshold limit values and volatilities for 214 industrial chemicals in air and water dilution. Journal of Applied Toxicology, 3(6):272-290. 1983.
A highly reactive manmade volatile organic com-
pound that is highly reactive in the atmosphere. It
readily reacts with oxidizing agents to release the
chlorine atoms which, circulate and cause tropo-
spheric ozone to decompose.
Ethyl chloride is used as synthetic gums and thickeners in the lacquer and plastics industries. Ethyl chloride is also used in the Friedel-Crafts alkylation of benzene and other aromatics. Additional uses include solvent, refrigerant, heat-transfer medium, aerosol propellant and anesthetic.