View source for Trichloroethylene

{{short description|C2HCl3, widely used industrial solvent}}
{{redirect|Trichlor|the reagent also known as "trichlor"|trichloroisocyanuric acid|Tri-clor|chloropicrin}}
{{chembox
| Verifiedfields = changed
| Watchedfields  = changed
| verifiedrevid  = 417962339
| ImageFile      = Trikloreten.svg
| ImageSize      = 150px
| ImageClass     = skin-invert
| ImageFileL1    = Trichloroethylene.png
| ImageFileR1    = Trichloroethylene-3D-vdW.png
| ImageFile2     = Trichloroethene.jpg
| ImageSize2     = 150px
| ImageCaption2  = Sample of trichloroethylene
| pronounce      = {{IPAc-en|t|r|ʌ|ɪ|ˌ|k|l|ɔː|r|ə|ʊ|ˈ|ɛ|θ|ɪ|l|iː|n}}
| PIN            = Trichloroethene
| OtherNames     = 1-Chloro-2,2-dichloroethylene; 1,1-Dichloro-2-chloroethylene; Acetylene Trichloride; Ethinyl Trichloride; Ethylene Trichloride<br /> Terchlorethylene; Chloréthérise ''(archaic)''<br />'''Trade names:''' Algylen; Anamenth; Chlorylene; Gemalgene;  Trethylene; Triclene; Trico; Triklone; Trilene; Trimar
| Section1       = {{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 13837280
| UNNumber = 1710
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 279816
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C2HCl3/c3-1-2(4)5/h1H
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = XSTXAVWGXDQKEL-UHFFFAOYSA-N
| SMILES1 = Cl\C=C(/Cl)Cl
| CASNo = 79-01-6
| CASNo_Ref = {{cascite|correct|CAS}}
| PubChem = 6575
| SMILES = Cl\C=C(/Cl)Cl
| Abbreviations = TCE, HCO-1120, Tri, Trichlor
| EINECS = 201-167-4
| SMILES2 = ClC=C(Cl)Cl
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 290YE8AR51
| InChI = 1/C2HCl3/c3-1-2(4)5/h1H
| RTECS = KX4550000
| MeSHName =
| ChEBI_Ref = {{ebicite|changed|EBI}}
| ChEBI = 16602
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = C06790
 }}
| Section2       = {{Chembox Properties
| C=2 | H=1 | Cl=3
| Appearance = Colorless liquid
| Odor = sweet, pleasant, [[chloroform]]-like
| Density = 1.46&nbsp;g/cm<sup>3</sup> at 20&nbsp;°C
| MeltingPtC = −84.8
| MeltingPt_ref = <ref>{{cite web|url=https://www.sigmaaldrich.com/US/en/sds/aldrich/133124|access-date=23 February 2022|title=Safety Data Sheet}}</ref>
| MeltingPt_notes = some sources also list –73 °C as the freezing point<ref>[https://www.osha.gov/chemicaldata/684 Trichloroethylene on OSHA]</ref>
| BoilingPtC = 86.7
| BoilingPt_ref = <ref name=":1"/>
| Solubility = 1.280&nbsp;g/L<ref name=":1">{{cite web|url=http://www.sigmaaldrich.com/catalog/product/sial/372145?lang=en|title=Trichloroethylene|publisher=Sigmaaldrich.com|access-date=20 October 2014}}</ref>
| SolubleOther = [[diethyl ether|Ether]], [[ethanol]], [[chloroform]]
| Solvent =
| pKa =
| pKb =
| IsoelectricPt =
| LambdaMax =
| Absorbance =
| SpecRotation =
| RefractIndex = 1.4777 at 19.8&nbsp;°C
| Viscosity = 0.532{{nbsp}}mPa·s<ref name="VenkatesuluVenkatesu1997">{{cite journal|last1=Venkatesulu|first1=D.|last2=Venkatesu|first2=P.|last3=Rao|first3=M. V. Prabhakara|title=Viscosities and Densities of Trichloroethylene or Tetrachloroethylene with 2-Alkoxyethanols at 303.15 K and 313.15 K|journal=Journal of Chemical & Engineering Data|volume=42|issue=2|year=1997|pages=365–367|issn=0021-9568|doi=10.1021/je960316f}}</ref>
| Dipole =
| VaporPressure = {{convert|58|mmHg|atm|abbr=on}} at 20&nbsp;°C<ref name=PGCH/>
| MagSus = −65.8·10<sup>−6</sup>{{nbsp}}cm<sup>3</sup>/mol
| LogP = 2.26<ref name="chemsrc">{{Cite web|url=https://www.chemsrc.com/en/cas/79-01-6_161631.html|title=Trichloroethylene|website=www.chemsrc.com}}</ref>
 }}
| Section3       = 
| Section4       = 
| Section5       = 
| Section6       = {{Chembox Pharmacology
| ATCCode_prefix = N01
| ATCCode_suffix = AB05
}}
| Section7       = {{Chembox Hazards
| ExternalSDS = [https://www.carlroth.com/medias/SDB-9579-AU-EN.pdf?context=bWFzdGVyfHNlY3VyaXR5RGF0YXNoZWV0c3wzMTg2MjV8YXBwbGljYXRpb24vcGRmfHNlY3VyaXR5RGF0YXNoZWV0cy9oMjEvaGU0LzkwNTM0NDM0NTcwNTQucGRmfDk2NGRjZDM1MGZiNzA5ZDM4MWUwZGY0OTI5ZjVmOWU0ZDE0YWY1ZjhiZDk3MTBiZGI1MDU5YjYyMGMyZjU5NGQ Carl Roth] 
| MainHazards = Acute exposure can cause dizziness and loss of consciousness, chronic exposure may increase cancer risk. Unstable in presence of sunlight and caustic soda.
| GHSPictograms = {{GHS08}} {{GHS07}} 
| FlashPt = 
| AutoignitionPtC = 420
| NFPA-H = 2
| NFPA-F = 1
| NFPA-R = 0
| NFPA-S =
| PEL = TWA 100 ppm C 200 ppm 300 ppm (5-minute maximum peak in any 2 hours)<ref name=PGCH>{{PGCH|0629}}</ref>
| ExploLimits = 8–10.5%<ref name=PGCH/>
| IDLH = Ca [1000 ppm]<ref name=PGCH/>
| REL = Ca<ref name=PGCH/>
| LD50 = 7000 mg/kg (oral, human)<ref>[https://www.inchem.org/documents/ehc/ehc/ehc50.htm#SectionNumber:1.2 Environmental Health Criteria: Trichloroethylene] International Programme on Chemical Safety</ref><br />4920 mg/kg (oral, rat), 29000 mg/kg (dermal, rabbit)<ref>[https://www.fishersci.com/store/msds?partNumber=T3414&productDescription=TRICHLOROETHYLENE+CR+ACS+4L&vendorId=VN00033897&countryCode=US&language=en FischerSci Trichloroethylene SDS]</ref>
| LC50 = 8450 ppm (mouse, 4 hr)<br />26300 ppm (rat, 1 hr)<ref name=IDLH>{{IDLH|79016|Trichloroethylene}}</ref>
| LCLo = 2900 ppm (human)<br />37,200 ppm (guinea pig, 40 min)<br />5952 ppm (cat, 2 hr)<br />8000 ppm (rat, 4 hr)<br />11,000 ppm (rabbit)<ref name=IDLH/>
 }}
| Section8       = {{Chembox Legal status
| legal_AU = 
| legal_BR = B1
| legal_BR_comment = <ref>{{Cite web |author=Anvisa |author-link=Brazilian Health Regulatory Agency |date=2023-03-31 |title=RDC Nº 784 - Listas de Substâncias Entorpecentes, Psicotrópicas, Precursoras e Outras sob Controle Especial |trans-title=Collegiate Board Resolution No. 784 - Lists of Narcotic, Psychotropic, Precursor, and Other Substances under Special Control|url=https://www.in.gov.br/en/web/dou/-/resolucao-rdc-n-784-de-31-de-marco-de-2023-474904992 |url-status=live |archive-url=https://web.archive.org/web/20230803143925/https://www.in.gov.br/en/web/dou/-/resolucao-rdc-n-784-de-31-de-marco-de-2023-474904992 |archive-date=2023-08-03 |access-date=2023-08-16 |publisher=[[Diário Oficial da União]] |language=pt-BR |publication-date=2023-04-04}}</ref>
| legal_US = banned for medical use (1977), all use banned (2024)
| legal_UK = 
| legal_UN = 
}}
| Section9       = {{Chembox Related
| OtherAnions =
| OtherCations =
| OtherFunction = [[Vinyl chloride]]<br />[[Tetrachloroethylene]]<br />[[Trifluoroethylene]] 
| OtherFunction_label = [[vinyl halide]]s
| OtherCompounds = [[Chloroform]]<br />[[1,1,1-Trichloroethane]]<br />[[1,1,2-Trichloroethane]]<br/>[[Chloral]]
}}
}}
'''Trichloroethylene''' ('''TCE''', [[International Union of Pure and Applied Chemistry|IUPAC]] name: '''trichloroethene''') is an [[organochloride]] with the formula C<sub>2</sub>HCl<sub>3</sub>, commonly used as an industrial degreaser. It is a clear, colourless, non-flammable, volatile liquid with a sweet [[chloroform]]-like pleasant mild smell<ref name=PGCH/> and burning sweet taste.<ref name=atsdr>[https://wwwn.cdc.gov/tsp/substances/toxsubstance.aspx?toxid=30 Trichloroethylene (TCE)] on [[ATSDR]]</ref> Trichloroethylene has been sold under a variety of trade names. Under the trade names '''Trimar''' and '''Trilene''', it was used as a [[inhalational anesthetic|volatile anesthetic]] and as an inhaled obstetrical [[analgesic]]. Industrial abbreviations include  '''trichlor''', '''Trike''', '''Tricky''' and '''tri'''. It should not be confused with the similar [[1,1,1-trichloroethane]], which was commonly known as ''chlorothene''.

==History==
The earliest trichloroethylene synthesis was reported by [[Auguste Laurent]] in 1836. Laurent obtained it from the action of [[potassium hydroxide]] on a mixture of [[1,1,2,2-Tetrachloroethane|1,1,2,2-tetrachloroethane]] and [[1,1,1,2-Tetrachloroethane|1,1,1,2-tetrachloroethane]] made from the chlorination of [[1,2-Dichloroethane|ethylene dichloride]] and notated it as {{chem2|C4HCl3}} (then the atomic weight of carbon was thought to be half of what it really is). He named trichloroethylene ''chlorétherise'' but did not investigate the compound further as his sample seemed unstable.<ref>''Essai sur l'Action du Chlore sur la Liqueur des Hollandais et sur quelques Ethers'' in Annales de Chimie, LXIII. (1836) [https://books.google.com/books?id=D1hOAAAAcAAJ&dq=%22essai%20sur%20l%27action%20du%20chlore%22&pg=PA379 page 379]</ref><ref>''The so-called Perchloride of Formyl'', Gmelin, L. (translated in 1855). Hand-book of Chemistry: Organic chemistry. UK: Cavendish Society. 
[https://books.google.com/books?id=BYwMAAAAYAAJ&dq=%22chlorethose%22%20laurent&pg=PA200 pages 200–201]</ref>

E. Fischer obtained trichloroethylene in 1864 via the reduction of [[hexachloroethane]] with hydrogen. Fischer investigated the compound and noted its boiling point as between 87 and 90 degrees Celsius.<ref>''Ueber die Einwirkung von Wasserstoff auf Einfach-Chlorkohlenstoff'', Fischer, E. (1864) in Zeitschrift für Chemie. [https://books.google.com/books?id=hhhDAQAAMAAJ page 268]</ref><ref>{{Cite journal |last1=Waters |first1=E. M. |last2=Gerstner |first2=H. B. |last3=Huff |first3=J. E. |date=January 1977 |title=Trichloroethylene. I. An overview |url=http://www.tandfonline.com/doi/abs/10.1080/15287397709529469 |journal=Journal of Toxicology and Environmental Health |language=en |volume=2 |issue=3 |pages=671–707 |doi=10.1080/15287397709529469 |pmid=403297 |bibcode=1977JTEH....2..671W |issn=0098-4108|url-access=subscription }}</ref><ref>Hardie DWF (1964). Chlorocarbons and chlorohydrocarbons. 1,1,2,2-Tetrachloroethane. In: Encyclopedia of Chemical Technology. Kirk RE, Othmer DF, editors. New York: John Wiley & Sons, pp. 159–164</ref>

Commercial production of trichloroethylene began in Germany, in 1920 and in the US in 1925.<ref>Mertens JA (1993). Chlorocarbons and chlorohydrocarbons. In: Kirk-Othmer Encyclopedia of Chemical Technology, 4th Ed. Kroschwitz JI, Howe-Grant M, editors. New York: John Wiley & Sons, pp. 40–50.</ref>

The use of trichloroethylene in the food and pharmaceutical industries has been banned in some parts of the world since the 1970s<ref name="FDA 1977 ban on cosmetic, food and medical use of trichloroethylne">{{cite web |title=Production, Import/Export, Use & Disposal of Trichloroethylene |url=https://www.atsdr.cdc.gov/toxprofiles/tp19-c5.pdf |website=Agency for Toxic Substances and Disease Registry |publisher=Centers for Disease Control and Prevention |access-date=20 January 2025}}</ref> due to concerns about its toxicity.

===Anaesthesia===
Trichloroethylene is a good analgesic at 0.35 to 0.5% concentrations.<ref name="textbook">Textbook of Obstetric Anaesthesia. (2002). UK:&nbsp;Greenwich Medical Media. Pages 64–65</ref> Trichloroethylene was used in the treatment of trigeminal neuralgia beginning in 1916.<ref name="forensic">{{Cite book |chapter-url=https://books.rsc.org/books/monograph/1916/chapter-abstract/2525934/ |chapter=Chapter 4. Trichloroethylene (TCE) |date=2013 |publisher=Royal Society of Chemistry |isbn=978-1-84973-196-6 |location=Cambridge |pages=119–159 |doi=10.1039/9781849737265-00119 |title=Chlorinated Solvents |series=Environmental Forensics }}</ref> Trichloroethylene for use as an analgesic for neuralgia were sold under the trade names "Gemalgene", "Trethylene" and "Chlorylen".

Pioneered by [[Imperial Chemical Industries]] in Britain, under the trade name "Trilene" (from ''tri''chloroethy''lene''), its development was hailed as an anesthetic revolution. It was also sold as "Trimar" in the United States. The ''–mar'' suffix  indicated study and development at the [[University of Maryland]], e.g., "Fluoromar" for [[fluroxene]] and "Vinamar" for [[ethyl vinyl ether]]".<ref>{{Cite book |last=John C. Krantz |first=Jr |url=https://archive.org/details/portraitofmedica0000john |title=A Portrait of Medical History and Current Medical Problems |date=1962 |publisher=The John D. Lucas Printing Company |page=160}}</ref> From the 1940s through the 1980s, both in Europe and North America, trichloroethylene was used as a volatile anesthetic almost invariably administered with [[nitrous oxide]]. Marketed in the UK by [[Imperial Chemical Industries]] under the trade name ''Trilene'' it was coloured blue with a dye called [[waxoline blue]] in 1:200,000 concentration<ref name="current">Current Researches in Anesthesia & Analgesia. (1951). USA:&nbsp;International Anesthesia Research Society. p.278</ref> to avoid confusion with the similar-smelling chloroform. ''Trilene'' was stabilised with 0.01% [[thymol]].<ref name=current/>  "Anamenth" was an early German anaesthetic trichloroethylene formulation which contained [[menthol]] as the stabiliser.

[[File:Cyprane Trilene inhaler.png|thumb|left|''Cyprane'' handheld anaesthetic device for trichloroethylene, made in the UK, 1947. This device was designed for self-administration by the patient.]]

Originally thought to possess less [[hepatotoxicity]] than [[chloroform]], and without the unpleasant pungency and flammability of [[diethyl ether|ether]], TCE replaced earlier anesthetics chloroform and ether in the 1940s. TCE use was nonetheless soon found to have several pitfalls. These included promotion of [[cardiac arrhythmias]], low volatility and high solubility preventing quick anesthetic induction, prolonged neurologic dysfunction from the reaction with [[soda lime]] used in carbon dioxide absorbing systems, and evidence of hepatotoxicity as had been found with chloroform. Alkali components of carbon dioxide absorbers reacted with trichloroethylene and released [[dichloroacetylene]], a neurotoxin.

The introduction of [[halothane]] in 1956 greatly diminished the use of TCE as a general anesthetic in the 1960s, as halothane allowed much faster induction and recovery times and was considerably easier to administer. Trichloroethylene has also been used in the production of halothane.<ref>{{Ref patent3 | country = US | number = 2921098 | status = granted | title = Process for the Preparation of 1,1,1-trifluoro-2-bromo-2-chloroethane | pubdate = 1958-06-30 | gdate =  January 1960 | pridate= 1954-08-20 | inventor = Suckling et al. | assign1= Imperial Chemical Industries | google_patent_id = 6JpaAAAAEBAJ }}</ref>

[[File:Bottle of trichloroethylene, England, 1940-1960 Wellcome L0065373.jpg|thumb|left|Bottle of trichloroethylene for anesthesia by ICI]] 
[[File:Trilene inhaler, London, England, 1961-1970 Wellcome L0065862.jpg|thumb|left|Inhaler used for Trilene, 1961–1970]] 
{{external media| float  = right | width  =| topic  =  | caption =  a short film by Imperial Chemical Industries explaining the use of nitrous oxide and trichloroethylene anaesthesia systems for childbirth.| headerimage= | title  =  ''Pain Relief in Childbirth'' (1954)| video1 = [https://archive.org/details/n2o-tce-54] 
}}

Trilene was also used as an inhaled analgesic, mainly during childbirth, often self-applied by the patient. It was introduced for obstetrical anaesthesia in 1943, and used until the 1980s.<ref name=textbook/> Its anaesthetic use was banned in the United States in 1977 but the anaesthetic use in the United Kingdom remained until the late 1980s (especially for childbirth).<ref name=forensic/> Fetal toxicity and concerns about the carcinogenic potential of TCE led to its abandonment in developed countries by the 1980s. TCE was used with halothane in the tri-service field anaesthetic apparatus used by the UK armed forces under field conditions. {{As of|2000}}, TCE was still in use as an anesthetic in Africa.<ref>{{cite web
 |title=Volatile Anaesthetic Agents |author=P. Fenton |year=2000 |access-date=2012-02-11 |url=http://www.nda.ox.ac.uk/wfsa/html/u11/u1115_02.htm |archive-url=https://web.archive.org/web/20120107011331/http://www.nda.ox.ac.uk/wfsa/html/u11/u1115_02.htm|archive-date=2012-01-07
 }}</ref>{{Update inline|date=January 2025}}

== Production ==
Today, most trichloroethylene is produced from [[ethylene]]. First, ethylene is chlorinated over a [[iron(III) chloride|ferric chloride]] catalyst to produce [[1,2-Dichloroethane|1,2-dichloroethane]]:<ref name=morrison2013/>

:CH<sub>2</sub>=CH<sub>2</sub> + Cl<sub>2</sub> → ClCH<sub>2</sub>CH<sub>2</sub>Cl

When heated to around 400&nbsp;°C with additional chlorine, 1,2-dichloroethane is converted to trichloroethylene:

:ClCH<sub>2</sub>CH<sub>2</sub>Cl + 2 Cl<sub>2</sub> → ClCH=CCl<sub>2</sub> + 3 HCl

This reaction can be catalyzed by a variety of substances. The most commonly used catalyst is a mixture of [[potassium chloride]] and [[aluminium chloride|aluminum chloride]]. However, various forms of porous [[carbon]] can also be used. This reaction produces [[tetrachloroethylene]] as a byproduct and depending on the amount of chlorine fed to the reaction, tetrachloroethylene can even be the major product. Typically, trichloroethylene and tetrachloroethylene are collected together and then separated by [[distillation]].<ref name=morrison2013/>

Prior to the early 1970s, however, most trichloroethylene was produced in a two-step process from [[acetylene]]. First, acetylene was treated with chlorine using a [[iron(III) chloride|ferric chloride]] [[catalyst]] at 90&nbsp;°C to produce [[1,1,2,2-Tetrachloroethane|1,1,2,2-tetrachloroethane]] according to the [[chemical equation]]:<ref name=morrison2013/>

:HC≡CH + 2 Cl<sub>2</sub> → Cl<sub>2</sub>CHCHCl<sub>2</sub>

The 1,1,2,2-tetrachloroethane is then dehydrochlorinated to give trichloroethylene. This can be accomplished either with an aqueous solution of [[calcium hydroxide]]:<ref name=morrison2013/>

:2 Cl<sub>2</sub>CHCHCl<sub>2</sub> + Ca(OH)<sub>2</sub> → 2 ClCH=CCl<sub>2</sub> + CaCl<sub>2</sub> + 2 H<sub>2</sub>O

or in the vapor phase by heating it to 300–500&nbsp;°C on a [[barium chloride]] or [[calcium chloride]] catalyst:

:Cl<sub>2</sub>CHCHCl<sub>2</sub> → ClCH=CCl<sub>2</sub> + HCl

Common impurities in reagent and technical grade TCE are [[methyl chloroform]], [[carbon tetrachloride]], [[ethylene dichloride]], [[tetrachloroethane]]s, [[benzene]] and [[phenol]]. However, these compounds are present in very small amounts and do not possess any risk.<ref name=forensic/>

== Uses ==
Trichloroethylene is an effective [[solvent]] for a variety of [[organic chemistry|organic]] materials. It is mainly used for cleaning. Trichloroethylene is an active ingredient (solvent) in various [[printing ink]], [[varnish]] and industrial [[paint]] formulations.<ref name="Subramanian 2023 t808">{{cite web | last=Subramanian | first=Indu | title=Is Most Parkinson's Disease Man-Made? | website=Medscape | date=20 Nov 2023 | url=https://www.medscape.com/viewarticle/997021 | access-date=29 Nov 2023}}</ref><ref name=forensic/> Other uses include [[dyeing]] and finishing operations, adhesive formulations, [[rubber]] processing, adhesives, [[lacquers]], and [[paint strippers]]. It is applied before [[plating]], [[anodizing]], and painting.<ref name="Caudle Guillot Lazo Miller 2012 pp. 178–188">{{cite journal | last1=Caudle | first1=W. Michael | last2=Guillot | first2=Thomas S. | last3=Lazo | first3=Carlos R. | last4=Miller | first4=Gary W. | title=Industrial toxicants and Parkinson's disease | journal=NeuroToxicology | publisher=Elsevier BV | volume=33 | issue=2 | year=2012 | issn=0161-813X | doi=10.1016/j.neuro.2012.01.010 | pages=178–188| pmid=22309908 | pmc=3299826 | bibcode=2012NeuTx..33..178C }}</ref>

When trichloroethylene was first widely produced in the 1920s, its major use was to extract [[vegetable oil]]s from plant materials such as [[soy]], [[coconut]], and [[palm tree|palm]]. Other uses in the food industry included [[coffee]] [[decaffeination]] (removal of [[caffeine]]) and the preparation of flavoring extracts from [[hops]] and [[spice]]s.<ref name=forensic/> TCE was used as a [[freezing point]] depressant in [[carbon tetrachloride]] fire extinguishers.<ref name=forensic/>

Trichloroethylene is also a [[chain termination|chain terminator]] for [[polyvinyl chloride]].<ref name=forensic/> Chlorination gives [[pentachloroethane]].

===Cleaning solvent===

Perhaps the greatest use of TCE is as a degreaser for metal parts. It has been widely used in degreasing and cleaning since the 1910s because of its low cost, low flammability, low toxicity, and high effectiveness as a solvent. The demand for TCE as a degreaser began to decline in the 1950s in favor of the less toxic [[1,1,1-Trichloroethane|1,1,1-trichloroethane]]. However, 1,1,1-trichloroethane production has been phased out in most of the world under the terms of the [[Montreal Protocol]] due to its contribution to the [[ozone depletion]]. As a result, trichloroethylene has experienced some resurgence in use as a degreaser.<ref name=forensic/>

Trichloroethylene has been used as a [[dry cleaning]] solvent, although mostly replaced by tetrachloroethylene, except for spot cleaning – for grease and oil stains – where it is still often used under various tradenames. It was found unfavourable for dry cleaning because it tended to dissolve acetate dyes, which tetrachloroethylene did not. Trichloroethylene is used to remove grease and [[lanolin]] from [[wool]] before [[weaving]].<ref name=forensic/>

TCE has also been used in the United States to clean kerosene-fueled rocket engines (TCE was not used to clean hydrogen-fueled engines such as the [[Space Shuttle Main Engine]]). During static firing, the [[RP-1]] fuel would leave hydrocarbon deposits and vapors in the engine. These deposits had to be flushed from the engine to avoid the possibility of explosion during engine handling and future firing. TCE was used to flush the engine's fuel system immediately before and after each test firing. The flushing procedure involved pumping TCE through the engine's fuel system and letting the solvent overflow for a period ranging from several seconds to 30–35 minutes, depending upon the engine. For some engines, the engine's gas generator and [[liquid oxygen]] (LOX) dome were also flushed with TCE before test firing.<ref>{{cite web |url=http://ssfl.msfc.nasa.gov/public-involvement/docs/SSFL_TCE_Final_Fact_Sheet.pdf |title=Santa Susana Field Laboratory: The Use of Trichloroethylene at NASA's SSFL Sites |publisher=Ssfl.msfc.nasa.gov |access-date=22 February 2015 |archive-url=https://web.archive.org/web/20131114001621/http://ssfl.msfc.nasa.gov/public-involvement/docs/SSFL_TCE_Final_Fact_Sheet.pdf |archive-date=14 November 2013 }}</ref><ref name="RocketdyneF1OperatingManual">{{cite web|url=https://archive.org/details/r-3896-11-f-1-rocket-engine-operating-instructions-09-oct-72|title=F-1 Rocket Engine Operating Instructions|date=9 October 1972 |publisher=Rocketdyne via Internet Archive|access-date=1 June 2025}}</ref>  The [[F-1 rocket engine]] had its LOX dome, gas generator, and thrust chamber fuel jacket flushed with TCE during launch preparations.<ref name="RocketdyneF1OperatingManual"/>

===Refrigerants===
TCE is also used in the manufacture of a range of fluorocarbon refrigerants<ref>{{cite web |url=http://www.nd.edu/~enviro/design/r134a.pdf |title=Production of R-134a |publisher=Nd.edu|access-date=21 February 2015 |archive-url=https://web.archive.org/web/20090711235310/http://www.nd.edu/~enviro/design/r134a.pdf |archive-date=11 July 2009 }}</ref> such as [[1,1,1,2-tetrafluoroethane]] more commonly known as HFC-134a.<ref>{{Cite web|url=http://www.solvay.us/en/binaries/PSS-Tetrafluoroethane-164368.pdf|title = Solvay in North America {{pipe}} Solvay}}</ref>
:CHCl=CCl{{sub|2}} + 4 HF → CF{{sub|3}}CH{{sub|2}}F + 3 HCl

TCE was also used in industrial refrigeration applications due to its high heat transfer capabilities and its low-temperature specification.{{citation needed|date=June 2025}}

== Reactions ==

Trichloroethylene reacts with alkalis to give [[dichloroacetylene]] via [[dehydrochlorination]].

1,1,2,2-tetrachloroethylsulfenyl chloride, used in the production of [[captafol]], is obtained from trichloroethylene and [[sulfur dichloride]]:
:{{chem2|C2HCl3 + SCl2 -> C2HCl4SCl}}

The reaction of trichloroethylene with chloroform can yield different compounds depending on the catalyst used. If sodium hydroxide is used, chloroform is dehydrochlorinated to [[dichlorocarbene]] which adds to trichloroethylene, and [[pentachlorocyclopropane]] is obtained:
:{{chem2|C2HCl3 + :CCl2 -> C3HCl5}}

The reaction of trichloroethylene with chloroform under the catalyst aluminum chloride gives [[1,1,1,2,3,3-Hexachloropropane]]:
:{{chem2|CHCl3 + C2HCl3 -> CHCl2CHClCCl3}}

The reaction of trichloroethylene with [[carbon tetrachloride]] under similar conditions gives 1,1,1,2,3,3,3-heptachloropropane:<ref>Asinger, F. "1,1,1,2,3,3-hexachloropropane" in Paraffins: Chemistry and Technology. Elsevier Science.</ref>
:{{chem2|C2HCl3 + CCl4 -> C3HCl7}}

==Safety==
===Chemical instability===
Despite its widespread use as a metal [[degreaser]], trichloroethylene itself is unstable in the presence of metal over prolonged exposure. As early as 1961 this phenomenon was recognized by the manufacturing industry when stabilizing additives were added to the commercial formulation. Since the reactive instability is accentuated by higher temperatures, the search for stabilizing additives was conducted by heating trichloroethylene to its boiling point under a [[reflux condenser]] and observing decomposition. Definitive documentation of [[1,4-dioxane]] as a stabilizing agent for TCE is scant due to the lack of specificity in early patent literature describing TCE formulations.<ref>{{Cite book|last1=Murphy|first1=Brian L|last2=Morrison|first2=Robert D.|date=2015|chapter=9. Source Identification and Age Dating of Chlorinated Solvents|title=Introduction to environmental forensics|publisher=[[Academic Press]]|isbn=978-0-12-404707-5|edition=3rd|at=sec. 9.2.2.1 1,4-Dioxane}}</ref><ref>{{Cite book|last=Mohr|first=Thomas K. G.|title=Environmental investigation and remediation: 1,4-dioxane and other solvent stabilizers|date=2010|publisher=[[CRC Press]]|isbn=978-1-56670-662-9|chapter=Historical Use of Chlorinated Solvents and Their Stabilizing Compounds|at=p. 53 "Was 1,4-Dioxane a Stabilizer for Trichloroethylene?"}}</ref> [[Epichlorohydrin]], [[butylene oxide]], ''N''-methyl[[pyrrole]] and [[ethyl acetate]] are common stabilisers for TCE, with epichlorohydrin being the most persistent and effective.<ref name=morrison2013>Morrison, R. D., Murphy, B. L. (2013). Chlorinated Solvents: A Forensic Evaluation. UK Royal Society of Chemistry.</ref> Other chemical stabilizers include [[ketone]]s such as [[methyl ethyl ketone]].
{{multiple image
 | width = 150
 | image1 = Du Pont Triclene D 1947.png
 | alt1 = [[DuPont]]'s ''Triclene D'', for degreasing metals (1946)
 | image2 = Trimar 1952 Ohio Chemical.png
 | alt2 = [[Ohio Chemical]]'s ''Trimar'', for anaesthesia (1952)
 | footer = Two advertisements for trichloroethylene in two different uses, metal degreasing (1947) and anaesthesia (1952)
}}

===Physiological effects===

==== Neurological ====
When inhaled, trichloroethylene produces [[central nervous system]] depression resulting in [[general anesthesia]]. These effects may be mediated by trichloroethylene acting as a [[positive allosteric modulator]] of inhibitory [[GABAA receptor|GABA<sub>A</sub>]] and [[glycine receptor]]s.<ref>{{Cite journal | author = M. J. Beckstead, J. L. Weiner, E. I. 2nd Eger, D. H. Gong & S. J. Mihic | title = Glycine and gamma-aminobutyric acid(A) receptor function is enhanced by inhaled drugs of abuse | journal = [[Molecular Pharmacology]] | volume = 57 | issue = 6 | pages = 1199–1205 | year = 2000 | doi = 10.1016/S0026-895X(24)23230-2 | pmid = 10825391}}</ref><ref>{{Cite journal | author = M. D. Krasowski & N. L. Harrison | title = The actions of ether, alcohol and alkane general anaesthetics on GABAA and glycine receptors and the effects of TM2 and TM3 mutations | journal = [[British Journal of Pharmacology]] | volume = 129 | issue = 4 | pages = 731–743 | year = 2000 | doi = 10.1038/sj.bjp.0703087 | pmid = 10683198
| pmc = 1571881 }}</ref> Its high blood solubility results in a less desirable slower induction of anesthesia. At low concentrations, it is relatively non-irritating to the respiratory tract. Higher concentrations result in [[tachypnea]]. Many types of cardiac [[arrhythmias]] can occur and are exacerbated by [[epinephrine]] (adrenaline). It was noted in the 1940s that TCE reacted with carbon dioxide (CO<sub>2</sub>) absorbing systems ([[soda lime]]) to produce [[dichloroacetylene]] by [[dehydrochlorination]] and [[phosgene]].<ref name=Orkin>Orkin, F. K. (1986) Anesthesia Systems (Chapter 5). In R. D. Miller (Ed.), Anesthesia (second edition). New York, NY: Churchill Livingstone.{{Page needed|date=May 2013}}</ref> [[Cranial nerve]] dysfunction (especially the fifth cranial nerve) was common when TCE anesthesia was given using CO<sub>2</sub> absorbing systems. Muscle relaxation with TCE anesthesia sufficient for surgery was poor. For these reasons as well as problems with [[hepatotoxicity]], TCE lost popularity in North America and Europe to more potent anesthetics such as [[halothane]] by the 1960s.<ref name=Stevens>Stevens, W.C. and Kingston H. G. G. (1989) Inhalation Anesthesia (Chapter 11). In P. G. Barash et al. (Eds.) Clinical Anesthesia.  Philadelphia, PA: Lippincott.{{Page needed|date=May 2013}}</ref>

The symptoms of acute non-medical exposure are similar to those of [[alcohol intoxication]], beginning with sleepiness, dizziness, and confusion and progressing with increasing exposure to unconsciousness.<ref name="epa.gov">{{cite web|url=http://www.epa.gov/ttn/atw/hlthef/tri-ethy.html |title=Trichloroethylene &#124; Technology Transfer Network Air Toxics Web site &#124; US EPA |publisher=Epa.gov |access-date=2013-10-05| archive-url=https://web.archive.org/web/20160216081108/https://www.epa.gov/ttn/atw/hlthef/tri-ethy.html| archive-date=February 16, 2016}}</ref> Much of what is known about the chronic human health effects of trichloroethylene is based on occupational exposures. Besides its effects on the central nervous system, industrial exposure to trichloroethylene is correlated with toxic effects in the liver and kidney.<ref name="epa.gov"/>

Long-term industrial<ref>{{cite journal |vauthors=Dorsey ER, Zafar M, Lettenberger SE, et al |title=Trichloroethylene: An Invisible Cause of Parkinson's Disease? |journal=J Parkinsons Dis |volume=13 |issue=2 |pages=203–218 |date=2023 |pmid=36938742 |doi=10.3233/JPD-225047 |pmc=10041423 }}</ref> or ambient environmental<ref>{{Cite journal |last1=Krzyzanowski |first1=Brittany |last2=Beyene |first2=Kassu Mehari |last3=Turner |first3=Jay R. |last4=Racette |first4=Brad A. |date=2025-10-21 |title=Ambient Trichloroethylene Exposure and Parkinson Disease Risk in Medicare Beneficiaries |journal=Neurology |volume=105 |issue=8 |article-number=e214174 |doi=10.1212/WNL.0000000000214174|pmid=41032742 |pmc=12488192 |doi-access=free }}</ref> exposure to trichloroethylene is suspected to elevate the risk of developing [[Parkinson's disease]].

=== Carcinogenicity ===
Trichloroethylene has been classified as "[[IARC group 1|Group 1]]: Carcinogenic to Humans" by the [[International Agency for Research on Cancer]] (IARC) due to sufficient evidence in humans and experimental animals for cancer of the kidney and a positive association between exposures to trichloroethylene and development of non-Hodgkin lymphoma and liver cancer in humans, and limited evidence in humans and experimental animals for increased incidence of leukemia, lymphoma, reproductive cancers, and respiratory cancers.<ref>{{Cite web |url=https://publications.iarc.fr/Book-And-Report-Series/Iarc-Monographs-On-The-Identification-Of-Carcinogenic-Hazards-To-Humans/Trichloroethylene-Tetrachloroethylene-And-Some-Other-Chlorinated-Agents-2014 |title=Trichloroethylene, Tetrachloroethylene, and Some Other Chlorinated Agents (IARC Monograph, Volume 106, 2014) |website=publications.iarc.fr/ |access-date=1 November 2025}}</ref>

====Metabolic====
Trichloroethylene is metabolised to trichloroepoxyethane (TCE oxide) which rapidly isomerises to [[trichloroacetaldehyde]] (chloral).<ref>Fishbein, L. (1977). Potential Industrial Carcinogens and Mutagens. Environmental Protection Agency, Office of Toxic Substances</ref> Chloral hydrates to [[chloral hydrate]] in the body. Chloral hydrate is either reduced to [[2,2,2-trichloroethanol]] or oxidised to [[trichloroacetic acid]]. [[Monochloroacetic acid]],<ref name=monitor/> [[dichloroacetic acid]]<ref>Biologically Based Methods for Cancer Risk Assessment. (2013). Springer US.</ref> and [[trichloromethane]]<ref name=monitor>''21.4.25: Trichloroethylene'' in Biological Monitoring: An Introduction. (1993). UK: Wiley.</ref><ref>Toxicological Profile for Trichloroethylene: Draft. (1995). U.S. Department of Health and Human Services.</ref><ref>Mutagenesis. (1978). page 268</ref> were also detected as minor metabolites of TCE.

=== Exposure and regulations ===
{{Main|List of trichloroethylene-related incidents}}
With a [[specific gravity]] greater than 1 (denser than water), trichloroethylene can be present as a [[dense non-aqueous phase liquid]] (DNAPL) if sufficient quantities are spilt in the environment.

The first known report of TCE in groundwater was given in 1949 by two English public chemists who described two separate instances of well contamination by industrial releases of TCE.<ref>Lyne FA, McLachlan T (1949). "Contamination of water by trichloroethylene" p. 513 in {{cite journal |doi=10.1039/AN9497400510 |title=Notes |year=1949 |last1=Lilliman |first1=B. |last2=Houlihan |first2=J. E. |last3=Lyne |first3=F. A. |last4=McLachlan |first4=T. |journal=The Analyst |volume=74 |issue=882 |pages=510–513|bibcode=1949Ana....74..510L }}</ref> Based on available federal and state surveys, between 9% and 34% of the drinking water supply sources tested in the US may have some TCE contamination, though EPA has reported that most water supplies comply with the maximum contaminant level (MCL) of 5&nbsp;ppb.<ref>{{cite web|url=http://www.epa.gov/safewater/pdfs/factsheets/voc/trichlor.pdf |archive-url=https://web.archive.org/web/20090515172629/http://www.epa.gov/safewater/pdfs/factsheets/voc/trichlor.pdf |archive-date=May 15, 2009 |title=Consumer Factsheet on: Trichloroethylene |publisher=Epa.gov |access-date=22 February 2015}}</ref>

Generally, atmospheric levels of TCE are highest in areas of concentrated industry and population. Atmospheric levels tend to be lowest in rural and remote regions. Average TCE concentrations measured in air across the United States are generally between 0.01 ppb and 0.3&nbsp;ppb, although mean levels as high as 3.4&nbsp;ppb have been reported.<ref name=":0a">{{Cite web |date=2022-09-09 |title=Trichloroethylene Toxicity: Where is Trichloroethylene Found? {{!}} Environmental Medicine {{!}} ATSDR |url=https://www.atsdr.cdc.gov/csem/trichloroethylene/where_found.html |access-date=2023-03-02 |website=www.atsdr.cdc.gov |language=en-us}}{{PD-notice}}</ref> TCE levels in the low parts per billion range have been measured in food; however, levels as high as 140&nbsp;ppb were measured in a few samples of food.<ref name=":0a" /> TCE levels above background{{how|date=August 2024}} have been found in homes undergoing [[renovation]].<ref>{{cite web |url=https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=P100BNS7.TXT |title= Trichloroethylene (tce) TEACH Chemical Summary - epa nepis}}</ref>

==== Existing regulations ====

State, federal, and international agencies classify trichloroethylene as a known or probable carcinogen for humans. In 2014, the [[International Agency for Research on Cancer]] updated its classification of trichloroethylene to [[IARC group 1 Carcinogens|Group 1]], indicating that sufficient evidence exists that it can cause cancer of the kidney in humans as well as some evidence of cancer of the liver and [[non-Hodgkin's lymphoma]].<ref>{{cite book|url=http://monographs.iarc.fr/ENG/Monographs/vol106/mono106-001.pdf |title=Trichloroethylene (IARC Summary & Evaluation, Volume 106, 2014) |publisher=iarc.fr |access-date=2016-03-08}}</ref>

In the [[European Union]], the [[Scientific Committee on Occupational Exposure Limit Values]] (SCOEL) recommends an exposure limit for workers exposed to trichloroethylene of 10&nbsp;ppm (54.7&nbsp;mg/m<sup>3</sup>) for 8-hour [[Permissible exposure limit|TWA]] and of 30&nbsp;ppm (164.1&nbsp;mg/m<sup>3</sup>) for [[Permissible exposure limit|STEL]] (15 minutes).<ref>{{cite web |url= http://ec.europa.eu/social/BlobServlet?docId=6405&langId=en |format= PDF |title= Recommendation from the Scientific Committee on Occupational Exposure Limits for Trichloroethylene (SCOEL/SUM/142) |date= April 2009}}</ref>

Existing EU legislation aimed at protection of workers against risks to their health (including Chemical Agents Directive 98/24/EC<ref>{{CELEX|31998L0024|text=Council Directive 98/24/EC of 7 April 1998 on the protection of the health and safety of workers from the risks related to chemical agents at work (fourteenth individual Directive within the meaning of Article 16(1) of Directive 89/391/EEC)}}</ref> and Carcinogens Directive 2004/37/EC<ref>

{{CELEX|02004L0037-20240408|text=Directive 2004/37/EC of the European Parliament and of the Council of 29 April 2004 on the protection of workers from the risks related to exposure to carcinogens, mutagens or reprotoxic substances at work (Sixth individual Directive within the meaning of Article 16(1) of Council Directive 89/391/EEC) (codified version)}}</ref>) currently do not impose binding minimum requirements for controlling risks to workers' health during the use phase or throughout the life cycle of trichloroethylene.

In 2023, the United States [[United States Environmental Protection Agency]] (EPA) determined that trichloroethylene presents a risk of injury to human health in various uses, including during manufacturing, processing, mixing, [[recycling]], vapor degreasing, as a lubricant, adhesive, [[sealant]], cleaning product, and spray. It is dangerous from both inhalation and [[dermal]] exposure and was most strongly associated with [[Immunosuppression|immunosuppressive]] effects for acute exposure, as well as [[Autoimmunity|autoimmune]] effects for chronic exposures.<ref>{{Cite web |last=US EPA |first=OCSPP |date=2020-02-12 |title=Final Risk Evaluation for Trichloroethylene |url=https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/final-risk-evaluation-trichloroethylene |access-date=2023-06-03 |website=[[United States Environmental Protection Agency]] |language=en |format=PDF}}</ref> Chronic exposure to trichloroethylene has also been linked to an increased risk of [[Parkinson's disease]].<ref name="Link to Parkinson's">{{cite journal |title=Trichloroethylene: An Invisible Cause of Parkinson's Disease? |publisher=National Library of Medicine |date=14 March 2023|pmc=10041423 |last1=Dorsey |first1=E. R. |last2=Zafar |first2=M. |last3=Lettenberger |first3=S. E. |last4=Pawlik |first4=M. E. |last5=Kinel |first5=D. |last6=Frissen |first6=M. |last7=Schneider |first7=R. B. |last8=Kieburtz |first8=K. |last9=Tanner |first9=C. M. |last10=De Miranda |first10=B. R. |last11=Goldman |first11=S. M. |last12=Bloem |first12=B. R. |journal=Journal of Parkinson's Disease |volume=13 |issue=2 |pages=203–218 |doi=10.3233/JPD-225047 |pmid=36938742 }}</ref><ref>{{cite news |last1=Wexler, MS |first1=Marisa |title=Ban sought for TCE, common chemical likely linked to Parkinson's |url=https://parkinsonsnewstoday.com/news/ban-sought-tce-common-chemical-likely-linked-parkinsons/ |access-date=30 January 2025 |work=Parkinson's News Today |publisher=BioNews |date=17 March 2023}}</ref> As of June 1, 2023, two U.S. states ([[Minnesota]] and [[New York (state)|New York]]) have acted on the EPA's findings and banned trichloroethylene in all cases but research and development.<ref>{{cite web
 |title=How Minnesota passed the country's first ban on trichloroethylene
 |date=28 August 2023
 |website=www.pca.state.mn.us/news-and-stories
 |publisher=Minnesota Pollution Control Agency
 |url=https://www.pca.state.mn.us/news-and-stories/tce-ban-in-effect
 |access-date=6 September 2023
 |url-status=live
 |archive-url=https://web.archive.org/web/20230906174016/https://www.pca.state.mn.us/news-and-stories/tce-ban-in-effect
 |archive-date=6 September 2023
 |language=en
}}</ref><ref>{{cite act 
 | type=act 
 | index=116.38 (also known as "White Bear Area Neighborhood Concerned Citizens Group Ban TCE Act")
 | date=2022 
 | article=Chapter 116, Section 116.385
 | article-type=Environmental Protection,  
 | title=Minnesota Statutes  
 | legislature=Minnesota Legislature
 | url=https://www.revisor.mn.gov/statutes/2022/cite/116.385
 | url-status=live
 | archive-url=https://web.archive.org/web/20230906174558/https://www.revisor.mn.gov/statutes/2022/cite/116.385
 | archive-date=6 September 2023 
 | language=en
}}</ref> According to the US EPA, in October 2023 it "proposed to ban the manufacture (including import), processing, and distribution in commerce of TCE for all uses, with longer compliance time frames and workplace controls (including an exposure limit) for some processing and industrial and commercial uses until the prohibitions come into effect" to "protect everyone including bystanders from the harmful health effects of TCE".<ref name="US EPA h041">{{cite web | title=Risk Management for Trichloroethylene (TCE) | website=US EPA | date=21 Nov 2023 | url=https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/risk-management-trichloroethylene-tce | access-date=23 Nov 2023}}</ref> Following the EPA's recommendation the [[Biden Administration]] announced a proposal to ban trichloroethylene later that month.<ref>{{cite news |title=Biden-Harris Administration Proposes Ban on Trichloroethylene to Protect Public from Toxic Chemical Known to Cause Serious Health Risks |url=https://www.epa.gov/newsreleases/biden-harris-administration-proposes-ban-trichloroethylene-protect-public-toxic |access-date=30 January 2025 |work=EPA Press Office |publisher=United States Environmental Protection Agency |date=23 October 2023}}</ref> In December 2024 the EPA issued a final ruling on the regulation of trichloroethylene, with the rule taking effect on January 16, 2025.<ref name="EPA's trichloroethylene takes effect">{{cite web |title=Final risk management rule for TCE |url=https://www.govinfo.gov/content/pkg/FR-2024-12-17/pdf/2024-29274.pdf |publisher=United States Environmental Protection Agency |access-date=30 January 2025}}</ref> The rule bans the manufacture (including import), processing, and distribution in commerce of trichloroethylene for all uses, with longer compliance timeframes and stringent worker protections for some processing and industrial and commercial uses until the prohibitions come into effect.<ref name="EPA trichloroethylene ban">{{cite web |title=Risk Management for Trichloroethylene (TCE) |url=https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/risk-management-trichloroethylene-tce |website=Assessing and Managing Chemicals under TSCA |publisher=United States Environmental Protection Agency |access-date=30 January 2025 |date=December 2024}}</ref> The EPA is prohibiting most uses of trichloroethylene within one year of the rule taking effect including manufacture and processing for most commercial and all consumer products, with only a limited number of commercial uses being allowed after January 16, 2026.<ref name="EPA phasing out commercial trichloroethylene use">{{cite web |title=Trichloroethylene (TCE); Regulation Under the Toxic Substances Control Act (TSCA) |url=https://www.federalregister.gov/documents/2024/12/17/2024-29274/trichloroethylene-tce-regulation-under-the-toxic-substances-control-act-tsca |website=National Archives Federal Register |publisher=United States Government |access-date=30 January 2025 |date=17 December 2024}}</ref> These uses will eventually be phased out as well, though an exact timeframe hasn't been determined yet, but until they have been phased out more stringent worker protections will be required with a lower [[inhalation]] [[Occupational exposure limit|exposure limit]] for [[Particulates|airborne]] trichloroethylene being put in place.<ref name="EPA trichloroethylene ban" /> Many of the trichloroethylene uses that are continuing for longer than one year occur in highly [[industrialized]] settings with critical uses such as the cleaning of parts used in [[medical devices]], aircraft & other transportation, [[Security alarm|security]] and [[U.S. critical infrastructure protection|defense systems]] and the manufacture of [[Lead–acid battery|battery]] [[Separator (electricity)|separators]] and [[refrigerants]].<ref name="EPA trichloroethylene ban" /> These uses will ultimately be prohibited as well but are temporarily being allowed to continue in order to avoid negative impacts to [[national security]] or [[critical infrastructure]], and to allow time to transition to alternative chemicals and methods.<ref name="EPA trichloroethylene ban" />

==Remediation==
Research has focused on the in-place remediation of trichloroethylene in soil and groundwater using [[potassium permanganate]] instead of removal for off-site treatment and disposal. Naturally occurring [[bacteria]] have been identified with the ability to degrade TCE. ''[[Dehalococcoides]]'' sp. degrade trichloroethylene by reductive dechlorination under anaerobic conditions. Under aerobic conditions, ''[[Pseudomonas fluorescens]]'' can co-metabolize TCE. Soil and groundwater contamination by TCE has also been successfully remediated by chemical treatment and extraction. The bacteria ''[[Nitrosomonas europaea]]'' can degrade a variety of halogenated compounds including trichloroethylene.<ref name="genome">{{cite web |url=http://genome.jgi-psf.org/finished_microbes/niteu/niteu.home.html |title=Nitrosomonas europaea |publisher=Genome.jgi-psf.org |date=2015-02-05 |access-date=2015-02-21 |archive-url=https://web.archive.org/web/20090703071550/http://genome.jgi-psf.org/finished_microbes/niteu/niteu.home.html |archive-date=2009-07-03 }}</ref> [[Toluene dioxygenase]] has been reported to be involved in TCE degradation by ''[[Pseudomonas putida]]''.<ref name="Irvine">{{cite book|url=https://books.google.com/books?id=oLNtgk_VKXsC&q=Bioremediation+of+gypsum&pg=PA81|title=Bioremediation Technologies: Principles and Practice|author1=Robert L. Irvine|author2=Subhas K. Sikdar|access-date=21 February 2015|isbn=978-1-56676-561-9|date=1998|pages=142, 144|publisher=CRC Press }}</ref> In some cases, ''[[Xanthobacter autotrophicus]]'' can convert up to 51% of TCE to CO and {{CO2}}.<ref name="Irvine"/>

==Society and culture==

Trichloroethylene has been used as a [[recreational drug]].<ref>[https://books.google.com/books?id=mpnaPQd_fZsC&dq=%22Trichloroethylene%22+%22recreational%22&pg=PT6077 ''Trichloroethylene''] in ''Neurology in Clinical Practice'', Daroff, R. B., Fenichel, G. M., Jankovic, J., Mazziotta, J. C. (2012)</ref> Reported methods of TCE abuse include inhalation and drinking.<ref name=abuse>[https://books.google.com/books?id=OWFiVaDZnkQC&dq=%22Trichloroethylene%22+%22abuse%22&pg=PA743 ''Chapter 50: Trichloroethylene''] Medical Toxicology of Drug Abuse: Synthesized Chemicals and Psychoactive Plants. Barceloux, D. G. (2012).</ref> It was abused for its euphoriant and slight hallucinogenic effect by mostly young people and workers who used the chemical.<ref name=abuse/> Some industrial workers had become addicted to TCE.<ref>''Trichlorethylene Addiction and its Effects'' (1972) Boleslaw Alapin M.D., M.R.C. Psych. British Journal of Addiction to Alcohol & Other DrugsVolume 68, Issue 4 p. 331–335 [[doi:10.1111/j.1360-0443.1973.tb01266.x|DOI]]</ref>

[[Groundwater pollution|Groundwater]] and [[Drinking water pollution|drinking water]] contamination from industrial discharge including trichloroethylene is a major concern for human health and has precipitated numerous incidents and lawsuits in the United States. One notable example is that of Woburn, Massachusetts, (''[[Anderson v. Cryovac]]'')  where improper disposal of industrial solvents including trichloroethylene by local companies led to the contamination of two municipal wells.<ref>{{cite journal |last1=Costas |first1=Kevin |last2=Knorr |first2=Robert S |last3=Condon |first3=Suzanne K |title=A case–control study of childhood leukemia in Woburn, Massachusetts: the relationship between leukemia incidence and exposure to public drinking water |journal=Science of the Total Environment |date=2 December 2002 |volume=300 |issue=1 |pages=23–35 |doi=10.1016/S0048-9697(02)00169-9 |pmid=12685468 |bibcode=2002ScTEn.300...23C }}</ref> Families blamed the supposed local increase in leukemia cases on trichloroethylene pollution,<ref>{{cite news |last1=Diperna |first1=Paula |title=Leukemia Strikes a Small Town |url=https://www.nytimes.com/1984/12/02/magazine/leukemia-strikes-a-small-town.html |access-date=28 October 2025 |work=New York Times |date=December 2, 1984}}</ref> although trichloroethylene does not cause leukemia in humans. The incident gained national attention in the 1980s and was the subject of extensive litigation, culminating in a settlement between the companies and affected families<ref>{{cite news |title=Record settlement reached in hazardous waste site - UPI Archives |url=https://www.upi.com/Archives/1991/07/08/Record-settlement-reached-in-hazardous-waste-site/8952678945600/ |work=UPI |language=en}}</ref> It later served as the basis for the book ''[[A Civil Action]]'' by Jonathan Harr, which was adapted [[A Civil Action (film)|adapted to cinema in 1998]].

==References==
{{Reflist}}

==Further reading==
* Agency for Toxic Substances and Disease Registry (ATSDR). 1997.   [https://web.archive.org/web/20110605235058/http://www.atsdr.cdc.gov/toxprofiles/tp19.html Toxicological Profile for Trichloroethylene.]
* {{cite journal |doi=10.1006/enfo.2000.0011 |title=A History of the Production and Use of Carbon Tetrachloride, Tetrachloroethylene, Trichloroethylene and 1,1,1-Trichloroethane in the United States: Part 2 – Trichloroethylene and 1,1,1-Trichloroethane |year=2000 |last1=Doherty |first1=Richard E. |journal=Environmental Forensics |volume=1 |issue=2 |pages=83–93|bibcode=2000EnvFo...1...83D |s2cid=97370778 }}
* {{cite journal |doi=10.1016/j.juro.2006.07.130 |title=The Epidemiology of Renal Cell Carcinoma |year=2006 |last1=Lipworth |first1=Loren |last2=Tarone |first2=Robert E. |last3=McLaughlin |first3=Joseph K. |journal=The Journal of Urology |volume=176 |issue=6 |pages=2353–2358 |pmid=17085101}}
* {{cite web | last=Matei | first=Adrienne | title=Rates of Parkinson's disease are exploding. A common chemical may be to blame | website=The Guardian | date=7 Apr 2021 | url=https://www.theguardian.com/commentisfree/2021/apr/07/rates-of-parkinsons-disease-are-exploding-a-common-chemical-may-be-to-blame}}
* US Environmental Protection Agency  (USEPA). 2011.  [https://web.archive.org/web/20111001035730/http://www.epa.gov/IRIS/supdocs/0199index.html Toxicological Review for Trichloroethylene]
* US National Academy of Sciences (NAS). 2006. [http://www.nap.edu/catalog/11707.html Assessing Human Health Risks of Trichloroethylene – Key Scientific Issues.] Committee on Human Health Risks of Trichloroethylene, National Research Council.
* US National Toxicology Program (NTP). 2021. [https://ntp.niehs.nih.gov/sites/default/files/ntp/roc/content/profiles/trichloroethylene.pdf Trichloroethylene, in the 15th Annual Report of Carcinogens.]

==External links==
{{commons category}}
* [https://web.archive.org/web/20050917135330/http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=119268 US EPA: Trichloroethylene – TCE information website] – US [[United States Environmental Protection Agency|Environmental Protection Agency]] (EPA)
* [https://www.chlorinated-solvents.eu/ chlorinated-solvents.eu] – Sustainable uses and industry recommendations, [[European Chlorinated Solvents Association]]
* [https://www.atsdr.cdc.gov/csem/csem.html Case Studies in Environmental Medicine: Trichloroethylene Toxicity] – [[Agency for Toxic Substances and Disease Registry]] (ATSDR), of the US [[Department of Health and Human Services]] (public domain)
* [https://nap.nationalacademies.org/catalog/11707/assessing-the-human-health-risks-of-trichloroethylene-key-scientific-issues Assessing Human Health Risks of Trichloroethylene – Key Scientific Issues] – US [[National Academy of Sciences]] (NAS)
* [https://ntp.niehs.nih.gov/sites/default/files/ntp/roc/content/profiles/trichloroethylene.pdf US NIH: Fifteenth Report on Carcinogens: Trichloroethylene Monograph] – US [[National Institutes of Health]] (NIH)
* [https://www.cdc.gov/niosh/topics/trichloroethylene/ Workplace Safety and Health Topics: Trichloroethylene – TCE] – US [[National Institute for Occupational Safety and Health]] (NIOSH)

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