Озон қабатын бұзғыш 1,1,1 Трихлорэтанның тоқтатылуы

Solvent, now banned for ozone depletion
chembox
| verifiedrevid = 477201594
| Name = 1,1,1 Trichloroethane
| ImageFileL1 Ref =
| ImageFile =
| ImageFileL1 = 1,1,1 trichloroethane 2D skeletal. png
| ImageSizeL1 = 140px
| ImageNameL1 = Skeletal formula of 1,1,1 trichloroethane
| ImageFileR1 = 1,1,1 trichloroethane 3D vdW. png
| ImageSizeR1 = 120px
| ImageNameR1 = Space filling model of 1,1,1 trichloroethane
| ImageFileL2= 1,1,1 Trichlorethan. svg
| ImageSizeL2 = 140px
| ImageFileR2 = 1,1,1 trichloroethane 3D balls. png
| ImageSizeR2 = 120px
| PIN = 1,1,1 Trichloroethane
| OtherNames = 1,1,1 TCA, Methyl chloroform, Chlorothene, Solvent 111, R 140a, Genklene, monochlorethylidene chloride (archaic)
| SystematicName =
| Section1 =
| Section2 =
| Section3 =
| Section4 =
| Section5 =
| Section6 =
| Section7 = Chembox Hazards
| MainHazards = Ozone layer impact. Irritant to the upper respiratory tract. Causes severe irritation and swelling to eyes. | NFPA H = 2
| NFPA F = 1
| NFPA R = 0
| GHSPictograms =
| GHSSignalWord = Warning
| HPhrases =
| PPhrases =
| PEL = TWA 350 ppm (1900 mg/m)
| ExploLimits = 7.5% 12.5%
| LD50 = 9600 mg/kg (oral, rat)6000 mg/kg (oral, mouse)5660 mg/kg (oral, rabbit) It is regulated by the Montreal Protocol as an ozone depleting substance and its use is being rapidly phased out.

1,1,1 Trichloroethane is an excellent solvent for many organic compounds and also one of the least toxic of the chlorinated hydrocarbons. It is generally considered non polar, but owing to the good polarizability of the chlorine atoms, it is a superior solvent for organic compounds that do not dissolve well in hydrocarbons such as hexane. Prior to the Montreal Protocol, it was widely used for cleaning metal parts and circuit boards, as a photoresist solvent in the electronics industry, as an aerosol propellant, as a cutting fluid additive, and as a solvent for inks, paints, adhesives, and other coatings. 1,1,1 Trichloroethane was used to dry clean leather and suede. 1,1,1 Trichloroethane is also used as an insecticidal fumigant. It was also the standard cleaner for photographic film (movie/slide/negatives, etc.). Other commonly available solvents damage emulsion and base (acetone will severely damage triacetate base on most films), and thus are not suitable for this application. The standard replacement, Forane 141 is much less effective, and tends to leave a residue. 1,1,1 Trichloroethane was used as a thinner in correction fluid products such as liquid paper. Many of its applications previously used carbon tetrachloride (which was banned in US consumer products in 1970). In turn, 1,1,1 trichloroethane itself is now being replaced by other solvents in the laboratory.

1,1,1 Trichloroethane was one of the volatile organochlorides that have been tried as alternatives to chloroform in anaesthesia. In the 1880s, it was found to be a safe and strong substitute for chloroform but its production was expensive and difficult. In 1880, 1,1,1 Trichloroethane was suggested as an anaesthetic. It was first referred to as "methyl chloroform" in the same year. At the time, the narcotic effects of chloral hydrate were owed to a hypothetical metabolic pathway to chloroform in "alkaline blood". Trichloroethane was studied for its structural similarity to chloral and potential anaesthetic effects. However, trichloroethane did not exhibit any conversion to chloroform in laboratory experiments. The 1,1,2 trichloroethane isomer, which lacked a trichloromethyl group, exhibited anaesthetic effects even stronger than the 1,1,1 isomer.

Although not as toxic as many similar compounds, inhaled or ingested 1,1,1 trichloroethane does act as a central nervous system depressant and can cause effects similar to those of ethanol intoxication, including dizziness, confusion, and, in sufficiently high concentrations, unconsciousness and death. Fatal poisonings and illnesses linked to intentional inhalation of trichloroethane have been reported. The removal of the chemical from correction fluid commenced due to Proposition 65 declaring it hazardous and toxic. Prolonged skin contact with the liquid can result in the removal of fats from the skin, resulting in skin irritation. The International Agency for Research on Cancer places 1,1,1 trichloroethane in Group 2A as a probable carcinogen.

The Montreal Protocol targeted 1,1,1 trichloroethane as one of those compounds responsible for ozone depletion and banned its use beginning in 1996. Since then, its manufacture and use have been phased out throughout most of the world. Its atmospheric presence has declined rapidly due to its relatively short atmospheric lifetime of about 5 years.