Chloroethane
Encyclopedia
Chloroethane or monochloroethane, commonly known by its old name ethyl chloride, is a chemical compound
with chemical formula
, once widely used in producing tetraethyllead, a gasoline
additive. It is a colorless, flammable gas or refrigerated liquid with a faintly sweet odor.
:
At various times in the past, ethyl chloride has also been produced from ethanol
and hydrochloric acid
, or from ethane
and chlorine
, but these routes are no longer economical. Some ethyl chloride is generated as a byproduct of polyvinyl chloride
production. Should demand for ethyl chloride continue to fall to the point where making it for its own sake is not economical, this may become the leading source of the chemical.
. TEL has been or is being phased out in most of the industrialized world, and the demand for ethyl chloride has fallen sharply. It also reacts with aluminium
metal to give ethylaluminium sesquichloride
, a precursor to polymers and other useful organoaluminium compounds.
Like other chlorinated hydrocarbon
s, ethyl chloride has been used as a refrigerant
, an aerosol spray propellant, an anesthetic, and a blowing agent
for foam packaging. For a time it was used as a promoter chemical in the aluminium chloride catalyzed process to produce ethylbenzene
, the precursor for styrene monomer. At present though, it is not widely used in any of these roles.
The only remaining industrially important use of ethyl chloride is in treating cellulose
to make ethylcellulose, a thickening agent and binder in paint
s, cosmetics
, and similar products.
Ethyl chloride is supplied as a liquid in a spray bottle propelled by its own vapor pressure. It acts as a mild topical anesthetic by its chilling effect when sprayed on skin, such as when removing splinters in a clinical setting. The heat absorbed by the boiling liquid on tissues produces a deep and rapid chill, but since the boiling point is well above the freezing point of water, it presents no danger of frostbite. The vapor is flammable and narcotic, which requires care.
Ethyl chloride is a recreational inhalant drug, sometimes referred to as "Duster". Similar to poppers, ethyl chloride is used as an inhalant (huffed) during sexual activity. In Brazil
, it is a traditional (though illegal) drug taken during Carnaval
parades, known as "lança-perfume".
depressant
, albeit a less potent one than many similar compounds. People breathing its vapors at less than 1% concentration in air usually experience no symptoms. At higher concentrations, victims usually exhibit symptoms similar to those of alcohol intoxication. Breathing its vapors at 15% or higher is often fatal.
Studies on the effects of chronic ethyl chloride exposure in animals have given inconsistent results, and there exist no data for its long-term effects on humans. Some studies have reported that prolonged exposure can produce liver
or kidney
damage, or uterine
cancer
in mice, but these data have been difficult to reproduce.
Chloroethane is not classifiable as to its carcinogenicity to humans (Group 3).
Recent information suggests carcinogenic potential; it has been designated as ACGIH category A3, Confirmed Animal Carcinogen with Unknown Relevance to Humans. As a result, the State of California has incorporated it into Proposition 65 as a known carcinogen. Nonetheless, it is still used in medicine as a local anesthetic
.
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
with chemical formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....
, once widely used in producing tetraethyllead, a gasoline
Gasoline
Gasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...
additive. It is a colorless, flammable gas or refrigerated liquid with a faintly sweet odor.
Production
Ethyl chloride is produced by hydrochlorination of ethyleneEthylene
Ethylene is a gaseous organic compound with the formula . It is the simplest alkene . Because it contains a carbon-carbon double bond, ethylene is classified as an unsaturated hydrocarbon. Ethylene is widely used in industry and is also a plant hormone...
:
- C2H4 + HCl → C2H5Cl
At various times in the past, ethyl chloride has also been produced from ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...
and hydrochloric acid
Hydrochloric acid
Hydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....
, or from ethane
Ethane
Ethane is a chemical compound with chemical formula C2H6. It is the only two-carbon alkane that is an aliphatic hydrocarbon. At standard temperature and pressure, ethane is a colorless, odorless gas....
and chlorine
Chlorine
Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...
, but these routes are no longer economical. Some ethyl chloride is generated as a byproduct of polyvinyl chloride
Polyvinyl chloride
Polyvinyl chloride, commonly abbreviated PVC, is a thermoplastic polymer. It is a vinyl polymer constructed of repeating vinyl groups having one hydrogen replaced by chloride. Polyvinyl chloride is the third most widely produced plastic, after polyethylene and polypropylene. PVC is widely used in...
production. Should demand for ethyl chloride continue to fall to the point where making it for its own sake is not economical, this may become the leading source of the chemical.
Uses
Beginning in 1922 and continuing through most of the 20th century, the major use of ethyl chloride was to produce tetraethyllead (TEL), an anti-knock additive for gasolineGasoline
Gasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...
. TEL has been or is being phased out in most of the industrialized world, and the demand for ethyl chloride has fallen sharply. It also reacts with aluminium
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....
metal to give ethylaluminium sesquichloride
Ethylaluminium sesquichloride
Ethylaluminium sesquichloride, also called EASC, is an industrially important organoaluminium compound used primarily as a precursor to triethylaluminium and as a catalyst component in Ziegler-Natta type systems for olefin and diene polymerizations...
, a precursor to polymers and other useful organoaluminium compounds.
Like other chlorinated hydrocarbon
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....
s, ethyl chloride has been used as a refrigerant
Refrigeration
Refrigeration is a process in which work is done to move heat from one location to another. This work is traditionally done by mechanical work, but can also be done by magnetism, laser or other means...
, an aerosol spray propellant, an anesthetic, and a blowing agent
Blowing agent
A blowing agent is a substance which is capable of producing a cellular structure via a foaming process in a variety of materials that undergo hardening or phase transition, such as polymers, plastics, and metals. They are typically applied when the blown material is in a liquid stage...
for foam packaging. For a time it was used as a promoter chemical in the aluminium chloride catalyzed process to produce ethylbenzene
Ethylbenzene
Ethylbenzene is an organic compound with the formula C6H5CH2CH3. This aromatic hydrocarbon is important in the petrochemical industry as an intermediate in the production of styrene, which in turn is used for making polystyrene, a common plastic material....
, the precursor for styrene monomer. At present though, it is not widely used in any of these roles.
The only remaining industrially important use of ethyl chloride is in treating cellulose
Cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to over ten thousand β linked D-glucose units....
to make ethylcellulose, a thickening agent and binder in paint
Paint
Paint is any liquid, liquefiable, or mastic composition which after application to a substrate in a thin layer is converted to an opaque solid film. One may also consider the digital mimicry thereof...
s, cosmetics
Cosmetics
Cosmetics are substances used to enhance the appearance or odor of the human body. Cosmetics include skin-care creams, lotions, powders, perfumes, lipsticks, fingernail and toe nail polish, eye and facial makeup, towelettes, permanent waves, colored contact lenses, hair colors, hair sprays and...
, and similar products.
Ethyl chloride is supplied as a liquid in a spray bottle propelled by its own vapor pressure. It acts as a mild topical anesthetic by its chilling effect when sprayed on skin, such as when removing splinters in a clinical setting. The heat absorbed by the boiling liquid on tissues produces a deep and rapid chill, but since the boiling point is well above the freezing point of water, it presents no danger of frostbite. The vapor is flammable and narcotic, which requires care.
Ethyl chloride is a recreational inhalant drug, sometimes referred to as "Duster". Similar to poppers, ethyl chloride is used as an inhalant (huffed) during sexual activity. In Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, it is a traditional (though illegal) drug taken during Carnaval
Brazilian Carnival
The Carnival of Brazil is an annual festival held forty-six days before Easter. On certain days of Lent, Roman Catholics and some other Christians traditionally abstained from the consumption of meat and poultry, hence the term "carnival," from carnelevare, "to remove meat." Carnival celebrations...
parades, known as "lança-perfume".
Safety
Ethyl chloride is the least toxic of the chloroethanes. Like other chlorinated hydrocarbons, it is a central nervous systemCentral nervous system
The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...
depressant
Depressant
A depressant, or central depressant, is a drug or endogenous compound that depresses the function or activity of a specific part of the brain...
, albeit a less potent one than many similar compounds. People breathing its vapors at less than 1% concentration in air usually experience no symptoms. At higher concentrations, victims usually exhibit symptoms similar to those of alcohol intoxication. Breathing its vapors at 15% or higher is often fatal.
Studies on the effects of chronic ethyl chloride exposure in animals have given inconsistent results, and there exist no data for its long-term effects on humans. Some studies have reported that prolonged exposure can produce liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
or kidney
Kidney
The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
damage, or uterine
Uterus
The uterus or womb is a major female hormone-responsive reproductive sex organ of most mammals including humans. One end, the cervix, opens into the vagina, while the other is connected to one or both fallopian tubes, depending on the species...
cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
in mice, but these data have been difficult to reproduce.
Chloroethane is not classifiable as to its carcinogenicity to humans (Group 3).
Recent information suggests carcinogenic potential; it has been designated as ACGIH category A3, Confirmed Animal Carcinogen with Unknown Relevance to Humans. As a result, the State of California has incorporated it into Proposition 65 as a known carcinogen. Nonetheless, it is still used in medicine as a local anesthetic
Local anesthetic
A local anesthetic is a drug that causes reversible local anesthesia, generally for the aim of having local analgesic effect, that is, inducing absence of pain sensation, although other local senses are often affected as well...
.
External links
- IARCInternational Agency for Research on CancerThe International Agency for Research on Cancer is an intergovernmental agency forming part of the World Health Organisation of the United Nations....
Monograph "Chloroethane." - National Pollutant Inventory - Chloroethane