Chloroethane, commonly known as ethyl chloride, is a chemical compound with the chemical formula CH3CH2Cl , once widely used in the production of tetraethylide , a gasoline additive. It is a colorless, flammable gas or refrigerated liquid with a slight sweet odour.
Production
Chloroethane is produced by hydrochlorination of ethylene: [9]C 2 H 4 + HCl → C 2 H 5 Cl
At various times in the past, chloroethane has been produced from ethanol and hydrochloric acid, from ethane and chlorine, or also from ethanol and phosphorus trichloride, but these routes are no longer economical. Some chloroethane is produced as a byproduct of polyvinyl chloride production. Should demand for chloroethane continue to fall to the point where it is no longer economical to make it for yourself, it could become a major source of the chemical.
Use
Ethyl chloride is a cheap ethylating agent. It reacts with aluminum metal to give ethylaluminium sesquichloride, a precursor to polymers and other useful organoaluminium compounds. [10] Chloroethane is used to convert cellulose to the ethylcellulose group, a thickening agent and binder in paints, cosmetics, and similar products.
Like other chlorinated hydrocarbons, chloroethane has been used as a refrigerant, aerosol spray propellant, anesthetic, and a blowing agent for foam packaging. For a time it was used as a promoter chemical in the aluminum chloride catalyzed process to produce ethylbenzene, the precursor to styrene monomer. Although currently, it is not widely used in any of these roles.
Obsolete usage
Beginning in 1922 and continuing through most of the 20th century, chloroethane’s major use was to produce tetraethylide (TEL), an anti-knock additive for gasoline. TEL is being phased out or being phased out in most of the industrialized world, and demand for chloroethane has declined sharply. [9]
Got used
It acts as a mild topical anesthetic by its chilling effect when sprayed onto the skin, such as in a clinical setting to remove splinters or inflame boils. This was standard equipment in “casualty” wards. It was commonly used to induce general anesthesia before continuing with di-ethyl ether, which had a very slow uptake.
The heat absorbed by the boiling liquid on the tissues produces a deep and sharp cold, but since the boiling point is well above the freezing point of water, there is no risk of frostbite.
In dentistry, chloroethane is used as a means of diagnosing a ‘dead tooth’, i.e. one in which the pulp has died. A small amount of the substance is placed on the suspicious tooth with the help of a cotton ball. The low boiling point of chloroethane produces a localized chilling effect. If the tooth is still alive, the patient should feel a slight pain that subsides when the wad is removed.
Security
The vapor is flammable and intoxicating, requiring care. Monochloroethane is the least toxic of chloroethane. Like other chlorinated hydrocarbons, it is a central nervous system depressant, although less potent than many similar compounds. People who inhale its vapor in concentrations less than 1% in the air usually do not experience any symptoms. At concentrations of 3% to 5%, victims usually exhibit symptoms similar to those of alcohol intoxication. Inhaling its vapors at 15% concentrations is often fatal but most commercially available handheld containers contain concentrated vapors at a total of 30% per volume that naturally diffuse into outdoor air.
Victims often exhibit shallow breathing, loss of consciousness and depressed heart rate if exposed to concentrations higher than 6% to 8%. They can be woken (brought around) by physical contact or loud noises. At this point it is advisable to remove from the area of exposure to restore consciousness. Long-term effects of exposure over a period of 4 or more hours will cause side effects similar to an alcohol hang-over with dehydration, dizziness, loss of clear vision and temporary loss of consciousness, which can last for an hour or more . If no longer exposed to the gas, the victim will quickly return to normal health. This can be helped by consuming extra fluids, vitamins, and sugars.
Toxic over-exposure begins at 9% to 12% concentrations, the heart rate drops further, the victim may have more shallow breathing or may stop all together, they do not respond to any external stimuli and are unintentional. I may begin to gasp, burp or vomit, which can lead to aspiration if the victim is not turned on their side. This constitutes a medical emergency and requires immediate action. It is advisable to move the victim to clean air and arrange for forceful breathing to purge the lungs of the toxic fumes. If the victim recovers quickly enough, hospitalization may not be required, but a medical examination will be required to ensure that no organ damage has occurred.
At >12% concentration, the victim’s heart, lungs and kidneys begin to fail. Immediate CPR and medical support measures may be needed to prevent fatal kidney, lung and heart failure.
Studies on the effects of chronic ethyl chloride exposure in animals have given inconsistent results, and no data exist for its long-term effects on humans. Some studies have reported that prolonged exposure can cause liver or kidney damage, or cancer of the uterus in rats, but these data have been difficult to reproduce.
While chloroethane is not specifically classified as having carcinogenicity to humans, [11] recent information suggests carcinogenic potential and is designated as ACGIH Category A3, of unknown relevance to humans. Animal carcinogens confirmed with . As a result, the US State of California has included it in Proposition 65 as a known carcinogen. Nonetheless, it is still used in medicine as a local anesthetic.
Recreational drug
Chlorethane is a recreational inhalant drug, although it should not be confused with duster or canned air, which is composed of fluorinated low-weight hydrocarbons such as tetrafluoromethane, chlorodifluoromethane, or other similar gas.
In Brazil, it is a traditional (though illegal) drug taken during carnival, known locally as “lanca-perfume”
