{{Short description|Solvent, now banned for ozone depletion}} {{Use British English|date=May 2024}} {{Use dmy dates|date=May 2024}} {{chembox | verifiedrevid = 477201594 | Name = 1,1,1-Trichloroethane | ImageFileL1_Ref = {{chemboximage|correct|??}} | ImageFile = | ImageFileL1 = 1,1,1-trichloroethane-2D-skeletal.png | ImageSizeL1 = 140px | ImageClassL1 = skin-invert | ImageNameL1 = Skeletal formula of 1,1,1-trichloroethane | ImageFileR1 = 1,1,1-trichloroethane-3D-vdW.png | ImageClassR1 = bg-transparent | ImageSizeR1 = 120px | ImageNameR1 = Space-filling model of 1,1,1-trichloroethane | ImageFileL2= 1,1,1-Trichlorethan.svg | ImageSizeL2 = 140px | ImageClassL2 = skin-invert | ImageFileR2 = 1,1,1-trichloroethane-3D-balls.png | ImageClassR2 = bg-transparent | ImageSizeR2 = 120px | PIN = 1,1,1-Trichloroethane | OtherNames = {{ubl |1,1,1-TCA |Methyl chloroform |Chlorothene |Solvent 111 |R-140a |Genklene |monochlorethylidene chloride (archaic) }} | SystematicName = | Section1 = {{Chembox Identifiers | CASNo = 71-55-6 | CASNo_Ref = {{cascite|correct|CAS}} | IUPHAR_ligand = 5482 | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChEBI_Ref = {{ebicite|correct|EBI}} | ChEBI = 36015 | ChEMBL_Ref = {{ebicite|correct|EBI}} | ChEMBL = 16080 | ChemSpiderID = 6042 | EC_number = 200-756-3 | Gmelin = 82076 | PubChem = 6278 | RTECS = KJ2975000 | UNNumber = 2831 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = 113C650IR1 | KEGG_Ref = {{keggcite|correct|kegg}} | KEGG = C18246 | InChI = 1/C2H3Cl3/c1-2(3,4)5/h1H3 | InChIKey = UOCLXMDMGBRAIB-UHFFFAOYAP | SMILES = ClC(Cl)(Cl)C | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/C2H3Cl3/c1-2(3,4)5/h1H3 | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = UOCLXMDMGBRAIB-UHFFFAOYSA-N }} | Section2 = {{Chembox Properties | Formula = {{chem2|C2H3Cl3}} or {{chem2|CH3CCl3}} | C = 2 |Cl = 3 |H = 3 | Appearance = Colourless liquid | Odor = mild, chloroform-like<ref name=PGCH/> | Density = {{ubl |{{val|{{round|1.37068|2}}|u=g/cm3}} ({{convert|0|C|F K}}) |{{val|{{round|1.34587|2}}|u=g/cm3}} ({{convert|15|C|F K}}) |{{val|{{round|1.32096|2}}|u=g/cm3}} ({{convert|30|C|F K}})<ref name="Physico"/> }} | Solubility = {{ubl |{{val|0.480|u=g/L}} ({{convert|20|C|F K}})<ref>{{cite web |url=http://www.inchem.org/documents/ehc/ehc/ehc136.htm |title=International Programme On Chemical Safety, Environmental Health Criteria 136 |date=1990 |publisher=World Health Organization, Geneva |access-date=2017-12-25}}</ref> |reacts slowly producing hydrochloric acid<ref name="FisherSDS"/> }} | MeltingPtC = -33 | MeltingPt_ref = <ref name="Sigma"/> | BoilingPtC = 74-76 | BoilingPt_ref = <ref name="Sigma"/> | LogP = 2.49 ({{cvt|20|C|F K}})<ref name="Sigma"/> | VaporPressure = {{cvt|100|mmHg|kPa}} ({{convert|20|C|F K}})<ref name=PGCH/> | RefractIndex = {{val|1.437|u=D}}<ref name="Physico">{{cite book |title=Physico-chemical constants of pure organic compounds |last=Timmermans |first=Jean |author-link=Jean Timmermans |publisher=Elsevier |edition=1 |orig-date=1 January 1950 |url=https://archive.org/details/physicochemicalc0001timm/page/242/mode/1up |url-access=registration |page=242 |isbn=978-0444405715 }}</ref> |Viscosity = {{val|0.86|u=cP}} ({{convert|20|C|F K}})<ref name="FisherSDS"/> }} | Section3 = | Section4 = | Section5 = | Section6 = | Section7 = {{Chembox Hazards | GHS_ref=<ref name="Sigma">{{Sigma-Aldrich |id=T54704 |name=1,1,1-trichloroethane |accessdate=6 January 2026}}</ref> | GHSPictograms = {{GHS07}}{{GHS08}} | GHSSignalWord = Danger | HPhrases = {{H-phrases|332|350|402|420}} | PPhrases = {{P-phrases|201|202|261|271|273|280|304+340+312|308+313|405|501|502}} | NFPA-H = 2 | NFPA-F = 1 | NFPA-R = 0 | NFPA-S = - | NFPA_ref = <ref name="FisherSDS">{{cite web |title=Material Safety Data Sheet - 1,1,1-Trichloroethane |url=https://southwest.tn.edu/ehs/msds/1-10/111%20Trichloroethane.pdf |website=southwest.tn.edu |publisher=Fisher Scientific |access-date=5 January 2026 |pages=2-4 |date=4 March 2013}}</ref> | AutoignitionPtF = 998 | AutoignitionPt_ref = <ref name="Sigma"/> | ExploLimits = {{val|7.5|–|15|u=%}}<ref name="Sigma"/> | LC50 = {{ubl |{{val|3911|u=mg/kg}} (mouse, 2 hr) |{{val|18000|u=ppm|fmt=commas}} (rat, 4 hr)<ref name=IDLH>{{IDLH|71556|Methyl chloroform}}</ref> }} | LD50 = {{ubl |''1,1,1-TCA'': |{{val|9600|u=mg/kg}} (oral, rat) |{{val|6000|u=mg/kg}} (oral, mouse) |{{val|5660|u=mg/kg}} (oral, rabbit)<ref name=IDLH/> |''1,4-dioxane (stabilizer)'': |{{val|7600|u=μL/kg}} (skin, rabbit)<ref name="FisherSDS"/> }} | TLV-TWA = {{val|350|u=ppm}} (''1,4-dioxane'': {{val|20|u=ppm}}, danger of cutaneous absorption) | TLV-STEL = {{val|450|u=ppm}} | TLV-C = {{val|350|u=ppm}} ({{val|1900|u=mg/m3}}) | PEL = {{ubl |{{val|350|u=ppm}} ({{val|1900|u=mg/m3}}, TWA)<ref name=PGCH>{{PGCH|0404}}</ref> |''1,4-dioxane'': {{val|100|u=ppm}} ({{val|360|u=mg/m3}}, TWA, skin)<ref name="Sigma"/> }} | REL = {{ubl |{{val|350|u=ppm}} ({{val|1900|u=mg/m3}}, C)<ref name=PGCH/> |''1,4-dioxane'': {{val|1|u=ppm}} ({{val|3.6|u=mg/m3}}, C, potential carcinogen, skin absorption)<ref name="Sigma"/> }} | IDLH = {{val|700|u=ppm}}<ref name=PGCH/> }} | Section8 = {{Chembox Related | OtherAnions = | OtherCations = | Function = | OtherFunctn = | OtherCpds = }} }}
'''1,1,1-Trichloroethane''', also known as '''methyl chloroform''' and '''chlorothene''', is a [[chloroalkane]] with the chemical formula {{chem2|CH3CCl3}}. It is an isomer of [[1,1,2-trichloroethane]]. A colourless and sweet-smelling liquid, it was once produced industrially in large quantities for use as a [[solvent]].<ref>{{Ullmann |first1=Manfred |last1=Rossberg |first2=Wilhelm |last2=Lendle |first3=Gerhard |last3=Pfleiderer |first4=Adolf |last4=Tögel |first5=Eberhard-Ludwig Dreher |last5=Ernst Langer |first6=Heinz |last6=Rassaerts |first7=Peter |last7=Kleinschmidt |first8=Heinz |last8=Strack |first9=Richard |last9=Cook |first10=Uwe |last10=Beck |first11=Karl-August |last11=Lipper |first12=Theodore R. |last12=Torkelson |first13=Eckhard |last13=Löser |first14=Klaus K. |last14=Beutel |first15=Trevor |last15=Mann |title=Chlorinated Hydrocarbons |doi=10.1002/14356007.a06_233.pub2}}.</ref> It is regulated by the [[Montreal Protocol]] as an ozone-depleting substance, and as such, use has declined since 1996. Trichloroethane should not be confused with the similar-sounding [[trichloroethene]] which is also commonly used as a solvent.
==Production== 1,1,1-Trichloroethane was first reported by [[Henri Victor Regnault]] in 1840. Industrially, it is usually produced in a two-step process from [[vinyl chloride]]. In the first step, vinyl chloride reacts with [[hydrogen chloride]] at {{cvt|20–50|C}} to produce [[1,1-Dichloroethane|1,1-dichloroethane]]:{{cn|date=January 2026}} :{{chem2|H2C\dCHCl + HCl -> CH3CHCl2}}
This reaction is [[catalyst|catalyzed]] by a variety of [[Lewis acids and bases|Lewis acids]], mainly [[aluminium chloride]], [[iron(III) chloride]], or [[zinc chloride]]. The 1,1-dichloroethane is then converted to 1,1,1-trichloroethane by reaction with [[chlorine]] under [[ultraviolet]] irradiation:{{cn|date=January 2026}} :{{chem2|CH3CHCl2 + Cl2 -> CH3CCl3 + HCl}}
This reaction proceeds at {{val|80|–|90|u=%}} yield, and the hydrogen chloride byproduct can be recycled to the first step in the process. The major side-product is the related compound 1,1,2-trichloroethane, from which the 1,1,1-trichloroethane can be separated by [[distillation]].{{cn|date=January 2026}}
A somewhat smaller amount is produced from the reaction of [[1,1-dichloroethene]] and hydrogen chloride in the presence of an iron(III) chloride catalyst:{{cn|date=January 2026}} :{{chem2|CH2\dCCl2 + HCl -> CH3CCl3}}
It is sold with stabilizers because it is unstable with respect to dehydrochlorination and attacks some metals. Stabilizers comprise up to 8% of the formulation, including acid scavengers (epoxides, amines) and [[chelating agents|complexants]]. One discontinued product contained only [[1,4-dioxane]] ({{val|2|1|u=%}}), while another chemical supplier included 2.5% 1,4-dioxane, 0.47% 1,2-butylene oxide, and 0.35% [[nitromethane]] as stabilizers.<ref name="FisherSDS"/><ref name="Sigma"/>
==Uses== 1,1,1-Trichloroethane is an excellent solvent for many [[organic compound]]s and also one of the least toxic of the [[chlorinated hydrocarbon]]s. It is generally considered [[Chemical_polarity#Nonpolar_molecules|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.{{cn|date=January 2026}}
It was used to [[Dry cleaning|dry-clean]] leather and suede and it was one of the components of [[Dow Chemical]]'s "Dowclene" dry cleaning fluid among with tetrachloroethylene, first marketed in the late 1930s. Use in dry-cleaning remained until the 1980s, meanwhile tetrachloroethylene is still widely used. It is also used as an [[insecticide|insecticidal]] [[fumigation|fumigant]].<ref name="morrison">{{cite book |last1=Morrison |first1=Robert D. |last2=Murphy |first2=Brian |title=Chlorinated solvents: a forensic evaluation |date=2013 |publisher=RSC Publishing |location=Cambridge |chapter=Chapter 6: Methyl Chloroform (1,1,1-TCA) |doi=10.1039/9781849737265-00186 |isbn=978-1-84973-196-6}}</ref>
It was also the standard cleaner for [[photographic film]]. Other commonly available solvents damage emulsion and base ([[acetone]] will dissolve triacetate base on most films), and thus are not suitable for this application. The standard replacement, [[1,1-Dichloro-1-fluoroethane|Forane 141]] is much less effective, and tends to leave a residue.{{cn|date=January 2026}} It was also 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.<ref>{{cite web |url=http://www.norden.org/pub/ebook/2003-516.pdf |url-status=dead |title=Use of Ozone Depleting Substances in Laboratories. |publisher=TemaNord |id=516/2003 |archive-url=https://web.archive.org/web/20080227052412/http://www.norden.org/pub/ebook/2003-516.pdf |archive-date=2008-02-27}}{{page needed|date=January 2026}}</ref> Phase-out of 1,1,1-Trichloroethane due to ozone depletion lead to a resurgence of the use of [[trichloroethylene]] in metal degreasing.<ref name=morrison/>
Methyl chloroform was also used as a veterinary [[anthelmintic]].{{cn|date=January 2026}}
===Early anaesthetic research=== {{undue weight section|to=an essentially "trivia question" usage of this chemical that never actually went anywhere outside of discussions between doctors that ended in the late 1800s, and deserves maybe one citation and a one-liner|date=January 2026}}
1,1,1-Trichloroethane was one of the volatile organochlorides that have been tried as alternatives to [[chloroform]] in anaesthesia.<ref>{{cite journal |title=Foreign Correspondence |journal=The American Practitioner |volume=23 |url=https://archive.org/details/sim_american-practitioner_1881-01_23/page/28/mode/1up |page=28 |orig-date=15 December 1880 |date=January 1881}}</ref> In the 1880s, it was found to be a safe and strong substitute for chloroform but its production was too expensive and difficult for the era.<ref>{{cite journal |editor1-last=James |editor1-first=Frank L. |editor2-last=Ohmann-Dumesnil |editor2-first=A. H. |title=Editorial Department - Surgery - Methyl Chloroform |journal=Saint Louis Medical and Surgical Journal |date=August 1887 |volume=53 |page=121 |url=https://archive.org/details/saintlouismedic08unkngoog/page/n128/mode/1up |access-date=6 January 2026 |oclc=11254212 |issn=1077-663X}}</ref><ref>{{cite book |last1=Brunton |first1=T. Lauder |title=An introduction to modern therapeutics: being the Croonian Lectures on the relationship between chemical structure and physiological action in relation to the prevention, control, and cure of disease delivered before the Royal College of Physicians in London, June 1889 |orig-date=20 June 1889 |date=1892 |publisher=Macmillian |location=London; New York |page=122 |url=https://archive.org/details/b20406204/page/122/mode/1up |chapter=Lecture III: Control and Cure of Disease |oclc=969481521 |ol=OL25611933M}}</ref>
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]] (vinyl trichloride) isomer, which lacked a [[trichloromethyl group]], exhibited anaesthetic effects even stronger than the 1,1,1 isomer.<ref>{{cite journal |last1=Sadtler |first1=Samuel P. |title=On Two New Anaesthetics |orig-date=1880 |journal=The American Journal of Pharmacy |date=March 1881 |volume=53 |url=https://archive.org/details/sim_american-journal-of-pharmacy-and-the-sciences_1881-03_53/page/119/mode/1up |pages=119-120 |publisher=Philadelphia College of Pharmacy |location=Philadelphia College of Pharmacy |issn=0730-7780}}</ref>
==Safety== Although not as [[toxicity|toxic]] as many similar compounds, inhaled or ingested 1,1,1-trichloroethane acts as a [[central nervous system]] [[depressant]] and can cause decrease in reaction times and dexterity as well as impaired balance and abnormal [[EEG]] at lower concentrations, throat irritation, and in sufficiently high concentrations, death.<ref>{{cite web |title=Toxicological Profile for 1,1,1-Trichloroethane |url=https://www.atsdr.cdc.gov/ToxProfiles/tp70.pdf |publisher=U.S. Department of Health and Human Services - Agency for Toxic Substances and Disease Registry |page=3 |date=March 2024 |orig-date=December 1990}}</ref>
The [[International Agency for Research on Cancer]] places 1,1,1-trichloroethane in [[IARC group 2A|Group 2A]] as a probable [[carcinogen]].<ref>{{Cite book |last=IARC |url=https://publications.iarc.fr/Book-And-Report-Series/Iarc-Monographs-On-The-Identification-Of-Carcinogenic-Hazards-To-Humans/1-1-1-Trichloroethane-And-Four-Other-Industrial-Chemicals-2022 |title=1,1,1-Trichloroethane and Four Other Industrial Chemicals |isbn=978-92-832-0197-7 |language=en}}</ref>
==Atmospheric concentration== [[File:CH3CCl3 mm.png|thumb|left|upright=1.2|{{chem2|CH3CCl3}} measured by the Advanced Global Atmospheric Gases Experiment<ref>{{cite web |last1=Chen |first1=Gao |title=AGAGE - Advanced Global Atmospheric Gases Experiment |url=https://www-air.larc.nasa.gov/missions/agage/ |website=www-air.larc.nasa.gov |publisher=NASA |access-date=6 January 2026}}</ref> in the lower atmosphere ([[troposphere]]) at stations around the world. Abundances are given as pollution free monthly mean mole fractions in [[Parts-per notation|parts-per-trillion]].]] [[File:BK MC.jpg|thumb|left|upright=1.0|1,1,1-Trichloroethane timeseries at various latitudes.]] 1,1,1-Trichloroethane is a fairly potent [[greenhouse gas]] with a 100-year [[global warming potential]] of 169 relative to [[carbon dioxide]].<ref name="Updated">{{cite journal |last1=Hodnebrog |first1=ø. |last2=Aamaas |first2=B. |last3=Fuglestvedt |first3=J. S. |last4=Marston |first4=G. |last5=Myhre |first5=G. |last6=Nielsen |first6=C. J. |last7=Sandstad |first7=M. |last8=Shine |first8=K. P. |last9=Wallington |first9=T. J. |title=Updated Global Warming Potentials and Radiative Efficiencies of Halocarbons and Other Weak Atmospheric Absorbers |journal=Reviews of Geophysics |date=September 2020 |volume=58 |issue=3 |doi=10.1029/2019RG000691 |pmid=33015672 |pmc=7518032 |bibcode=2020RvGeo..5800691H}}</ref> This is nonetheless less than a tenth that of [[carbon tetrachloride]] — which it replaced as a solvent — due to its relatively short [[Greenhouse gas#Atmospheric lifetime|atmospheric lifetime]] of about 5 years.<ref name="AR5">{{cite report |editor1=Stocker, T.F. |editor2=D. Qin, G.-K. |editor3=Plattner, M. |editor4=Tignor, S.K. |editor5=Allen, J. |editor6=Boschung, A. |editor7=Nauels, Y. |editor8=Xia, V. Bex |editor9=Midgley, P.M. |location=Cambridge, United Kingdom and New York, NY, USA |periodical=IPCC |year=2013 |publisher=Cambridge University Press |url=https://www.ipcc.ch/report/ar5/wg1/ |contribution=Chapter 8, Table 8.A.1 |title=Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change |page=733}}</ref>
The Montreal Protocol targeted 1,1,1-trichloroethane as a compound 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, and its atmospheric concentration has declined substantially.<ref name="AR5"/>
{{clear}} ==See also== * [[1,1,2-Trichloro-1,2,2-trifluoroethane]]
==References== {{Reflist|30em}}
{{Authority control}} {{GABAA receptor positive modulators}} {{Glycine receptor modulators}} {{Ionotropic glutamate receptor modulators}} {{Sedatives}} {{Serotonin receptor modulators}}
{{DEFAULTSORT:Trichloroethane, 1, 1, 1-}} [[Category:5-HT3 agonists]] [[Category:Chloroalkanes]] [[Category:Dry cleaning]] [[Category:Excipients]] [[Category:GABAA receptor positive allosteric modulators]] [[Category:Glycine receptor agonists]] [[Category:Greenhouse gases]] [[Category:Halogenated solvents]] [[Category:Hypnotics]] [[Category:Ozone-depleting chemical substances]] [[Category:Sedatives]] [[Category:IARC Group 2A carcinogens]]