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			{{short description|C2HCl3, widely used industrial solvent}}
	{{chembox <!-- infobox -->
			{{redirect|Trichlor|the reagent also known as "trichlor"|trichloroisocyanuric acid|Tri-clor|chloropicrin}}
	| verifiedrevid = 410156289
			{{more citations needed|date=January 2021}}
	| ImageFileL1=Trichloroethene.svg
			{{chembox
	| ImageSizeL1=120px
			| Verifiedfields = changed
	| ImageFileR1=Trichloroethylene-3D-vdW.png
			| Watchedfields = changed
	| ImageSizeR1=120px
			| verifiedrevid = 417962339
	| IUPACName=trichloroethene
			| ImageFile = Trikloreten.svg
	| OtherNames = 1,1,2-Trichloroethene, 1,1-Dichloro-2-Chloroethylene, 1-Chloro-2,2-Dichloroethylene, Acetylene Trichloride, TCE, Trethylene, Triclene, Tri, Trimar, Trilene
			| ImageSize = 150px
			| ImageClass = skin-invert
			| ImageFileL1 = Trichloroethylene.png
			| ImageFileR1 = Trichloroethylene-3D-vdW.png
			| ImageFile2 = Trichloroethene.jpg
			| ImageSize2 = 150px
			|ImageCaption2 = sample of Trichloroethylene
			| PIN = Trichloroethene
			| OtherNames = 1-Chloro-2,2-dichloroethylene; 1,1-Dichloro-2-chloroethylene; Acetylene Trichloride; Anamenth; HCO-1120; TCE; Trethylene; Triclene; Tri; Trico; Trilene; Trimar;<br /> Terchlorethylene; Chloréthérise ''(archaic)''
	| Section1 = {{Chembox Identifiers		| Section1 = {{Chembox Identifiers
	| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}		| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
	| ChemSpiderID = 13837280		| ChemSpiderID = 13837280
			| UNNumber = 1710
	| ChEMBL_Ref = {{ebicite|correct|EBI}}		| ChEMBL_Ref = {{ebicite|correct|EBI}}
	| ChEMBL = 279816		| ChEMBL = 279816
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	| SMILES1 = Cl\C=C(/Cl)Cl		| SMILES1 = Cl\C=C(/Cl)Cl
	| CASNo = 79-01-6		| CASNo = 79-01-6
	| CASNo_Ref = {{cascite|correct|CAS}}		| CASNo_Ref = {{cascite|correct|CAS}}
	| PubChem = 6575		| PubChem = 6575
	| SMILES = Cl\C=C(/Cl)Cl		| SMILES = Cl\C=C(/Cl)Cl
	| Abbreviations = TCE		| Abbreviations = TCE
	| EINECS = 201-61-04		| EINECS = 201-167-4
	| SMILES = ClC=C(Cl)Cl		| SMILES2 = ClC=C(Cl)Cl
	| UNII_Ref = {{fdacite|correct|FDA}}		| UNII_Ref = {{fdacite|correct|FDA}}
	| UNII = 290YE8AR51		| UNII = 290YE8AR51
	| InChI = 1/C2HCl3/c3-1-2(4)5/h1H		| InChI = 1/C2HCl3/c3-1-2(4)5/h1H
	| RTECS = KX4550000		| RTECS = KX4550000
	| MeSHName =		| MeSHName =
			| ChEBI_Ref = {{ebicite|changed|EBI}}
	| ChEBI =
	| KEGG_Ref = {{keggcite|correct|kegg}}		| ChEBI = 16602
			| KEGG_Ref = {{keggcite|correct|kegg}}
	| KEGG = C06790		| KEGG = C06790
			}}
	| ATCCode =
	}}
	| Section2 = {{Chembox Properties		| Section2 = {{Chembox Properties
	| C = 2 | H = 1 | Cl = 3		| C=2 | H=1 | Cl=3
			| Appearance = Colorless liquid
	| MolarMass = 131.4 g/mol
			| Odor = pleasant, ]-like
	| Appearance = Colorless liquid
	| Density = 1.46 g/cm&sup3; (liquid) at 20 °C		| Density = 1.46&nbsp;g/cm<sup>3</sup> at 20&nbsp;°C
			| MeltingPtC = −84.8
	| MeltingPt = 200 K (−73 °C)
			| 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>
	| BoilingPt = 360 K (87.2 °C)<ref name="ChemIDplus"/>
			| MeltingPt_notes =
	| Solubility = 1.280 g/L (25°C)<ref name="ChemIDplus"> on ]</ref>
			| BoilingPtC = 86.7
	| Melting_notes =
			| BoilingPt_ref = <ref name=":1"/>
	| Boiling_notes =
			| 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 = ], ], ]
			| SolubleOther = ], ], ]
	| Solvent =
	| pKa =		| Solvent =
	| pKb =		| pKa =
	| IsoelectricPt =		| pKb =
			| IsoelectricPt =
	| LambdaMax =		| LambdaMax =
	| Absorbance =		| Absorbance =
	| SpecRotation =		| SpecRotation =
	| RefractIndex = 1.4777 at 19.8 °C		| 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>
	| Viscosity =
	| Dipole =		| 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
	| Section3 = {{Chembox Hazards
			| 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>
	| ExternalMSDS =
			}}
	| MainHazards = Harmful if swallowed or inhaled.
	| FlashPt =		| Section3 =
			| Section4 =
	| Autoignition = 420 °C
	| NFPA-H = 2		| Section5 =
			| Section6 = {{Chembox Pharmacology
	| NFPA-F = 1
	| NFPA-R =		| ATCCode_prefix = N01
	| NFPA-O =		| ATCCode_suffix = AB05
	}}
	| Section8 = {{Chembox Related
	| OtherAnions =
	| OtherCations =
	| OtherFunctn = ]
	| Function = ]
	| OtherCpds = ]<br>]<br/>]
	}}
	}}		}}
			| Section7 = {{Chembox Hazards
	The ] '''trichloroethylene''' is a ] ] commonly used as an industrial ]. It is a clear non-flammable liquid with a sweet smell.
			| ExternalSDS =
			| MainHazards = Acute exposure can cause dizziness and loss of consciousness, chronic exposure can increase cancer risk. Unstable in presence of sunlight and caustic soda.
	The ] name is '''trichloroethene'''. Industrial abbreviations include '''TCE''', '''trichlor''', '''Trike''', '''Tricky''' and '''tri'''. It has been sold under a variety of trade names. Under the trade names '''Trimar''' and '''Trilene''', trichloroethylene was used as a volatile ] and as an inhaled obstetrical ] in millions of patients.
			| 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 <ref name=PGCH/>
			| REL = Ca<ref name=PGCH/>
			| LD50 = 4920 mg/kg (oral, rat), 29000 mg/kg (dermal, rabbit)<ref></ref>
			| LC50 = 8450 ppm (mouse, 4 hr)<br />26300 (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 (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=] |language=pt-BR |publication-date=2023-04-04}}</ref>
			| legal_US = banned for medical use (1977)
			| legal_UK =
			| legal_UN =
			}}
			| Section9 = {{Chembox Related
			| OtherAnions =
			| OtherCations =
			| OtherFunction = ]<br>]<br>]
			| OtherFunction_label = ]s
			| OtherCompounds = ]<br>]<br />]<br/>]
			}}
			}}
			'''Trichloroethylene''' ('''TCE''') is a ] with the formula C<sub>2</sub>HCl<sub>3</sub>, commonly used as an ] degreasing ]. It is a clear, colourless, non-flammable, volatile liquid with a ]-like pleasant mild smell<ref name=PGCH/> and sweet taste.<ref name=atsdr> on ]</ref> Its ] name is '''trichloroethene'''. Trichloroethylene has been sold under a variety of trade names. Industrial abbreviations include '''TCE''', '''trichlor''', '''Trike''', '''Tricky''' and '''tri'''. Under the trade names '''Trimar''' and '''Trilene''', it was used as a ] and as an inhaled obstetrical ]. It should not be confused with the similar ], which was commonly known as ''chlorothene''.
	==History==		==History==
			The earliest record of trichloroethylene synthesis dates back to 1836. It was obtained from the action of ] on ] and ] by ] and notated as {{chem2|C4HCl3}} (then the atomic weight of carbon was thought to be the half of it really was). Laurent did not investigate the compound further.<ref>''Essai sur l'Action du Chlore sur la Liqueur des Hollandais et sur quelques Ethers'' in Annal. de Chimie, LXIII. (1836) </ref><ref>''The so-called Perchloride of Formyl'', Gmelin, L. (translated in 1855). Hand-book of Chemistry: Organic chemistry. UK: Cavendish Society.
	Pioneered by ] in Britain, its development was hailed as an anesthetic revolution. Originally thought to possess less ] than ], and without the unpleasant pungency and flammability of ], TCE use was nonetheless soon found to have several pitfalls. These included promotion of ], too low a volatility for quick anesthetic induction, reactions with ] used in carbon dioxide absorbing systems, prolonged neurologic dysfunction when used with soda lime, and evidence of hepatotoxicity as had been found with chloroform.
			</ref>
			Trichloroethylene's discovery is widely attributed to E. Fischer who made it in 1864 via the reduction of ] with hydrogen. Fischer investigated TCE 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. </ref><ref>{{Cite journal |last=Waters |first=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 |issn=0098-4108}}</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 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 introduction of ] in 1956 greatly diminished the use of TCE as a general anesthetic. TCE was still used as an inhalation analgesic in childbirth given by self-administration. Fetal toxicity and concerns for carcinogenic potential of TCE led to its abandonment in the 1980s.
	Due to concerns about its toxicity, the use of trichloroethylene in the food and pharmaceutical industries has been banned in much of the world since the 1970s. Legislation has forced the substitution of trichloroethylene in many processes in Europe as the chemical was classified as a carcinogen carrying an R45 risk phrase. Many degreasing chemical alternatives are being promoted such as Ensolv and Leksol, however each of these is based on ] which carries an R60 risk phrase and they would not be a legally acceptable substitute.		The use of trichloroethylene in the food and pharmaceutical industries has been banned in much of the world since the 1970s due to concerns about its toxicity. Legislation has forced the replacement of trichloroethylene in many processes in Europe as the chemical was classified as a carcinogen carrying an R45 ], ''May cause cancer''. Many degreasing chemical alternatives are being promoted such as Ensolv and Leksol; however, each of these is based on ] which carries an R60 risk phrase of ''May impair fertility'', and would not be a legally acceptable substitute.
			===Anaesthesia===
			Trichloroethylene is a good analgesic at 0.35 to 0.5% concentrations.<ref name=textbook>Textbook of Obstetric Anaesthesia.&nbsp;(2002).&nbsp;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 |url=https://books.rsc.org/books/monograph/1916/chapter-abstract/2525934/ |title=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}}</ref>
			Pioneered by ] in Britain, under the trade name "Trilene" (from ''tri''chloroethy''lene'') , its development was hailed as an anesthetic revolution. It was mostly known as "Trimar" in the United States. The ''–mar'' suffix indicates study and development at the ], e.g., "Fluoromar" for ] and "Vinamar" for ]".<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 |pages=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 ]. Marketed in the UK by ] under the trade name ''Trilene'' it was coloured blue (with a dye called ] in 1:200,000 concentration)<ref name=current>Current Researches in Anesthesia & Analgesia.&nbsp;(1951).&nbsp;USA:&nbsp;International Anesthesia Research Society. p.278</ref> to avoid confusion with the similar-smelling chloroform. ''Trilene'' was stabilised with 0.01% ].<ref name=current/> ]
	] contamination by TCE has become an important environmental concern. Seepage of the compound into groundwater has raised health concerns in many locations.
			Originally thought to possess less ] than ], and without the unpleasant pungency and flammability of ], TCE replaced earlier anesthetics ] and ] in the 1940s. TCE use was nonetheless soon found to have several pitfalls. These included promotion of ], low volatility and high solubility preventing quick anesthetic induction, reactions with ] used in carbon dioxide absorbing systems, prolonged neurologic dysfunction when used with soda lime, and evidence of hepatotoxicity as had been found with chloroform. Alkali components of carbon dioxide absorbers reacted with trichloroethylene and released ], a neurotoxin.
	== Production ==
	Prior to the early 1970s, most trichloroethylene was produced in a two-step process from ]. First, acetylene was treated with chlorine using a ] ] at 90 °C to produce ] according to the ]
			The introduction of ] 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 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>
	:] + 2 ] → ]
			]
	The 1,1,2,2-tetrachloroethane is then dehydrochlorinated to give trichloroethylene. This can either be accomplished with an aqueous solution of ]
			]
			{{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 =
			}}
			Trilene was also used as an inhaled analgesic, mainly during childbirth, often self-applied by the patient. Trichloroethylene 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
	:2 Cl<sub>2</sub>CHCHCl<sub>2</sub> + ] → 2 ClCH=CCl<sub>2</sub> + ] + 2 H<sub>2</sub>O
			|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 |url-status=dead |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>
			== Production ==
	or in the vapor phase by heating it to 300-500°C on a ] or ] catalyst
			Today, most trichloroethylene is produced from ]. First, ethylene is chlorinated over a ] catalyst to produce ]:
	:Cl<sub>2</sub>CHCHCl<sub>2</sub> → ClCH=CCl<sub>2</sub> + ]		: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:
	Today, however, most trichloroethylene is produced from ]. First, ethylene is chlorinated over a ] catalyst to produce ].
	:] + Cl<sub>2</sub> → ]		: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 ] and ]. However, various forms of porous ] can also be used. This reaction produces ] 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 ].
	When heated to around 400 °C with additional chlorine, 1,2-dichloroethane is converted to trichloroethylene
			Prior to the early 1970s, however, most trichloroethylene was produced in a two-step process from ]. First, acetylene was treated with chlorine using a ] ] at 90&nbsp;°C to produce ] according to the ]:
	:] + 2 Cl<sub>2</sub> → ClCH=CCl<sub>2</sub> + 3 HCl
			:HC≡CH + 2 Cl<sub>2</sub> → Cl<sub>2</sub>CHCHCl<sub>2</sub>
	This reaction can be catalyzed by a variety of substances. The most commonly used catalyst is a mixture of ] and ]. However, various forms of porous ] can also be used. This reaction produces ] 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 ].
			The 1,1,2,2-tetrachloroethane is then dehydrochlorinated to give trichloroethylene. This can be accomplished either with an aqueous solution of ]:
	== Uses ==
	Trichloroethylene is an effective ] for a variety of ] materials.
			: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
	When it was first widely produced in the 1920s, trichloroethylene's major use was to extract ]s from plant materials such as ], ], and ]. Other uses in the food industry included ] ] and the preparation of flavoring extracts from ] and ]s. It has also been used for drying out the last bit of water for production of 100% ethanol.
			or in the vapor phase by heating it to 300–500&nbsp;°C on a ] or ] catalyst:
	From the 1930s through the 1970s, both in Europe and North America, trichloroethylene was used as a volatile gas anesthetic. TCE was used in place of the earlier anesthetics ] and ] in the 1940s, but was itself replaced in the 1950s by the newer ], which allowed much faster induction and recovery times. Marketed in the UK by ICI under the trade name Trilene it was coloured blue (with a dye called waxolene blue) to avoid confusion with the similar smelling chloroform.
			:Cl<sub>2</sub>CHCHCl<sub>2</sub> → ClCH=CCl<sub>2</sub> + HCl
	It has also been used as a ] solvent, although replaced in the 1950s by ] (also known as perchloroethylene).
			Common impurities in reagent and technical grade TCE are ], ], ], ]s, ] and ]. However, these compounds are present in very small amounts and do not possess any risk.<ref name=forensic/>
	Trichloroethylene was marketed as 'Ecco 1500 Anti-Static Film Cleaner and Conditioner' until 2009, for use in automatic movie film cleaning machines, and for manual cleaning with lint-free wipes.
			== Uses ==
	Perhaps the greatest use of TCE has been as a degreaser for metal parts. The demand for TCE as a degreaser began to decline in the 1950s in favor of the less toxic ]. However, 1,1,1-trichloroethane production has been phased out in most of the world under the terms of the ], and as a result trichloroethylene has experienced some resurgence in use as a degreaser.
			Trichloroethylene is an effective ] for a variety of ] materials. It is mainly used for cleaning. Trichloroethylene is an active ingredient (solvent) in various ], ] and industrial ] 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 ] and finishing operations, adhesive formulations, ] processing, adhesives, ], and ]. It is applied before ], ], 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 ]s from plant materials such as ], ], and ]. Other uses in the food industry included ] ] (removal of ]) and the preparation of flavoring extracts from ] and ]s.<ref name=forensic/> TCE was used a ] depressant in ] fire extinguishers.<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 ]). 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 LOX dome were also flushed with TCE prior to test firing.<ref></ref><ref></ref>. The ] had its LOX dome, gas generator, and thrust chamber fuel jacket flushed with TCE during launch preprations.<ref></ref>
			Trichloroethylene is also a ] for ].<ref name=forensic/> Chlorination gives ].
	TCE is also used in the manufacture of a range of fluorocarbon refrigerants<ref>http://www.nd.edu/~enviro/design/r134a.pdf</ref> such as ] more commonly known as HFC 134a
			===Cleaning solvent===
	==Chemical instability==
			TCE has also been used as a ] solvent, although mostly replaced by ], except for spot cleaning where it is still used under the trade name Picrin.{{citation needed|date=November 2023}}
			Perhaps the greatest use of TCE is as a degreaser for metal parts. It has been widely used in degreasing and cleaning since the 1920s because of its low cost, low flammability, low toxicity and high effectivity as a solvent. The demand for TCE as a degreaser began to decline in the 1950s in favor of the less toxic ]. However, 1,1,1-trichloroethane production has been phased out in most of the world under the terms of the ] due to its contribution to the ]. As a result, trichloroethylene has experienced some resurgence in use as a degreaser.<ref name=forensic/>
	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 in 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 in a ] and observing decomposition. The first widely used stabilizing additive was ]; however, its use was patented by ] and could not be used by other manufacturers. Considerable research took place in the 1960s to develop alternative stabilizers for trichloroethylene. Other chemical stabilizers include ]s such as ].
			Trichloroethylene is used to remove grease and ] from ] before ].<ref name=forensic/>
	==Physiological effects==
	When inhaled, trichloroethylene produces ] depression resulting in general ]. 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 ]. Many types of cardiac ] can occur and are exacerbated by ] (adrenaline). It was noted in the 1940s that TCE reacted with carbon dioxide (CO<sub>2</sub>) absorbing systems (]) to produce dichloroacetylene and ].<ref name=Orkin>Orkin, F. K. (1986) Anesthesia Systems (Chapter 5). In R. D. Miller (Ed.), Anesthesia (second edition). New York, NY: Churchill Livingstone.</ref> ] dysfunction (especially the fifth cranial nerve) was not uncommon when TCE anesthesia was given using CO<sub>2</sub> absorbing systems. These nerve deficits could last for months. Occasionally facial numbness was permanent. Muscle relaxation with TCE anesthesia sufficient for surgery was poor. For these reasons as well as problems with ], TCE lost popularity in North America and Europe to more potent anesthestics such as ] 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.</ref>
			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 ]). 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 ] (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 |url-status=dead |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="ntrs.nasa.gov">{{cite web|url=https://ntrs.nasa.gov/search.jsp?N=0&Ntk=all&Ntx=mode%20matchall&Ntt=19750070175|title=F-1 Rocket Engine Operating Instructions|publisher=Ntrs.nasa.gov|access-date=20 October 2014}}</ref> The ] had its LOX dome, gas generator, and thrust chamber fuel jacket flushed with TCE during launch preparations.<ref name="ntrs.nasa.gov"/>
	The symptoms of acute non-medical exposure are similar to those of ], beginning with headache, dizziness, and confusion and progressing with increasing exposure to unconsciousness.<ref name="epa.gov">http://www.epa.gov/ttn/atw/hlthef/tri-ethy.html</ref> Respiratory and circulatory depression can result in death.
			===Refrigerants===
	Much of what is known about the human health effects of trichloroethylene is based on occupational exposures. Beyond the effects to the central nervous system, workplace exposure to trichloroethylene has been associated with toxic effects in the liver and kidney <ref name="epa.gov"/>. Over time, occupational exposure limits on trichloroethylene have tightened, resulting in more stringent ventilation controls and personal protective equipment use by workers.
			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 |url-status=dead |archive-url=https://web.archive.org/web/20090711235310/http://www.nd.edu/~enviro/design/r134a.pdf |archive-date=11 July 2009 }}</ref> such as ] more commonly known as HFC 134a. TCE was also used in industrial refrigeration applications due to its high heat transfer capabilities and its low-temperature specification.
			==Safety==
	Research from Cancer bioassays performed by the ] (later the ]) showed that exposure to trichloroethylene is carcinogenic in animals, producing liver cancer in mice, and kidney cancer in rats.<ref name="epa.gov"/><ref>http://www.atsdr.cdc.gov/toxprofiles/phs19.html</ref> Research published in 1994 examined the incidence of ] and ] in populations exposed to TCE in their drinking water.<ref>New Jersey Department of Health, Environmental Health Services, Trenton, NJ 08625 USA.</ref>
			===Chemical instability===
			Despite its widespread use as a metal ], 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 ] and observing decomposition. Definitive documentation of ] 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=]|isbn=978-0124047075|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=]|isbn=978-1566706629|chapter=Historical Use of Chlorinated Solvents and Their Stabilizing Compounds|at=p. 53 "Was 1,4-Dioxane a Stabilizer for Trichloroethylene?"}}</ref> ], ], ''N''-methyl] and ] are common stabilisers for TCE, with epichlorohydrin being the most persistent and effective.<ref>Morrison, R. D., Murphy, B. L. (2013). Chlorinated Solvents: A Forensic Evaluation. UK Royal Society of Chemistry.</ref> Other chemical stabilizers include ]s such as ].
			{{multiple image
			| width = 150
			| image1 = Du Pont Triclene D 1947.png
			| alt1 = ]'s ''Triclene D'', for degreasing metals (1946)
			| image2 = Trimar 1952 Ohio Chemical.png
			| alt2 = ]'s ''Trimar'', for anaesthesia (1952)
			| footer = Two advertisements for trichloroethylene in two different uses, metal degreasing (1947) and anaesthesia (1952)
			}}
			===Physiological effects===
	The National Toxicology Program’s 11th Report on Carcinogens categorizes trichloroethylene as “reasonably anticipated to be a human carcinogen”, based on limited evidence of carcinogenicity from studies in humans and sufficient evidence of carcinogenicity from studies in experimental animals.<ref>http://ntp.niehs.nih.gov/index.cfm?objectid=72016262-BDB7-CEBA-FA60E922B18C2540/</ref>
			When inhaled, trichloroethylene produces ] depression resulting in general ]. These effects may be mediated by trichloroethylene acting as a ] of inhibitory ] and ]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 = ] | volume = 57 | issue = 6 | pages = 1199–1205 | year = 2000 | 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 = ] | 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 ]. Many types of cardiac ] can occur and are exacerbated by ] (adrenaline). It was noted in the 1940s that TCE reacted with carbon dioxide (CO<sub>2</sub>) absorbing systems (]) to produce ] by ] and ].<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> ] 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 ], TCE lost popularity in North America and Europe to more potent anesthetics such as ] 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 ], beginning with headache, 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}}</ref> Much of what is known about the chronic human health effects of trichloroethylene is based on occupational exposures. Besides the effects to the central nervous system, workplace exposure to trichloroethylene has been associated with toxic effects in the liver and kidney.<ref name="epa.gov"/> A history of long-term exposure to high concentrations of trichloroethylene is a suspected environmental risk of ].<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>
	One recent review of the epidemiology of ] rated cigarette smoking and obesity as more important risk factors for kidney cancer than exposure to solvents such as trichloroethylene.<ref></ref> In contrast, the most recent overall assessment of human health risks associated with trichloroethylene states, "here is concordance between animal and human studies, which supports the conclusion that trichloroethylene is a potential kidney carcinogen".<ref name="autogenerated1"></ref> The evidence appears to be less certain at this time regarding the relationship between humans and liver cancer observed in mice, with the NAS suggesting that low-level exposure might not represent a significant liver cancer risk in the general population.
			====Metabolism====
	Recent studies in laboratory animals and observations in human populations suggest that exposure to trichloroethylene might be associated with congenital heart defects <ref>J Am Coll Cardiol. 1990 Jul;16(1):155-64.</ref><ref>J Am Coll Cardiol. 1993 May;21(6):1466-72</ref><ref>Toxicol Sci. 2000 Jan;53(1):109-17</ref><ref>Birth Defects Res A Clin Mol Teratol. 2003 Jul;67(7):488-95</ref><ref>Environ Health Perspect. 2006 Jun;114(6):842-7</ref> While it is not clear what levels of exposure are associated with cardiac defects in humans, there is consistency between the cardiac defects observed in studies of communities exposed to trichloroethylene contamination in groundwater, and the effects observed in laboratory animals. A study published in August 2008, has demonstrated effects of TCE on human mitochondria. The article questions whether this might impact female reproductive function.
			Trichloroethylene is metabolised to trichloroepoxyethane (TCE oxide) which rapidly isomerises to ] (chloral).<ref>Fishbein, L. (1977). Potential Industrial Carcinogens and Mutagens. Environmental Protection Agency, Office of Toxic Substances</ref> Chloral hydrates to ] in the body. Chloral hydrate is either reduced to ] or oxidised to ]. ],<ref name=monitor/> ]<ref>Biologically Based Methods for Cancer Risk Assessment. (2013). Springer US.</ref> and ]<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.
	<ref>{{cite journal |author=Xu F, Papanayotou I, Putt DA, Wang J, Lash LH |title=Role of mitochondrial dysfunction in cellular responses to S-(1,2-dichlorovinyl)-L-cysteine in primary cultures of human proximal tubular cells |journal=Biochem. Pharmacol. |volume=76 |issue=4 |pages=552–67 |year=2008 |month=August |pmid=18602084 |doi=10.1016/j.bcp.2008.05.016 |url= |pmc=2593897}}</ref>
			=== Exposure and regulations ===
	The health risks of trichloroethylene have been studied extensively. The ] (EPA) sponsored a "state of the science" review of the health effects associated with exposure to trichloroethylene.<ref></ref> The ] concluded that evidence on the carcinogenic risk and other potential health hazards from exposure to TCE has strengthened since EPA released their toxicological assessment of TCE, and encourages federal agencies to finalize the risk assessment for TCE using currently available information, so that risk management decisions for this chemical can be expedited.<ref name="autogenerated1" />
			{{Main|List of trichloroethylene-related incidents}}
			With a ] greater than 1 (denser than water), trichloroethylene can be present as a ] (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 ppb.<ref>{{cite web|url=http://www.epa.gov/safewater/pdfs/factsheets/voc/trichlor.pdf |title=Consumer Factsheet on: Trichloroethylene |publisher=Epa.gov |access-date=22 February 2015}}</ref>
	== Human exposure==
	{{Globalize|section|date=February 2010}}
			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 ppb, although mean levels as high as 3.4 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 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 ].<ref>{{cite web |url=https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=P100BNS7.TXT |title= Trichloroethylene (tce) TEACH Chemical Summary - epa nepis}}</ref>
	Some are exposed to TCE through contaminated drinking water.<ref></ref>
	With a specific gravity greater than 1, trichloroethene can be present as a ] if sufficient quantities are spilled in the environment. Another significant source of vapor exposure in Superfund sites that had contaminated groundwater, such as the Twin Cities Army Ammunition Plant, was by showering. TCE readily volatilizes out of hot water and into the air. Long, hot showers would then volatilize more TCE into the air. In a home closed tightly to conserve the cost of heating and cooling, these vapors would then recirculate.
			==== Existing regulations ====
	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, F.A. and T. McLachlan, "Contamination of water by trichloroethylene," The Analyst, 74, p. 513, 1949.</ref> Based on available federal and state surveys, between 9% to 34% of the drinking water supply sources tested in the U.S. may have some TCE contamination, though EPA has reported that most water supplies are in compliance with the Maximum Contaminant Level (MCL) of 5 ppb.<ref> EPA - Consumer Factsheet on: TRICHLOROETHYLENE</ref> In addition, a growing concern in recent years at sites with TCE contamination in soil or groundwater has been vapor intrusion in buildings, which has resulted in indoor air exposures, such is in a recent case in the McCook Field Neighborhood of Dayton, Ohio.<ref name="test">EPA Long-Term Study Begins http://www.epa.gov/Region5/sites/behr/pdfs/behr-factsheet-200809.pdf Behr-Dayton Thermal Systems VOC Plume Site</ref> Trichloroethylene has been detected in 852 Superfund sites across the United States,<ref></ref> according to the ] (ATSDR). Under the Safe Drinking Water Act of 1974, and as amended <ref>http://www.epa.gov/safewater/sdwa/</ref>
	annual water quality testing is required for all public drinking water distributors. The EPA'S current guidelines for TCE can be found . It should be noted that the EPA's table of "TCE Releases to Ground" is dated 1987 to 1993, thereby omitting one of the largest Superfund Cleanup sites in the nation, the NIBW in Scottsdale, Arizona. The TCE "released" here occurred prior to its appearance in the municipal drinking wells in 1982.<ref>http://yosemite.epa.gov/r9/sfund/r9sfdocw.nsf/webdisplay/oid-3a4364e2a3ab3c7688256de9006819f2?OpenDocument</ref>
			State, federal, and international agencies classify trichloroethylene as a known or probable carcinogen for humans. In 2014, the ] updated its classification of trichloroethylene to 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 ].<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 1998, the ] in ] was found to have been contaminated with high levels of TCE. It was estimated that 25,000 factory workers had been exposed to it from 1950–2001.<ref>http://www.atsdr.cdc.gov/HAC/pha/PHA.asp?docid=293&pg=0</ref>
			In the ], the ] (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 ] and of 30&nbsp;ppm (164.1&nbsp;mg/m<sup>3</sup>) for ] (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>
	As of 2007, 57,000 pounds, or roughly 19 tons of TCE have been removed from the system of wells that once supplied drinking water to the residents of Scottsdale.<ref>http://www.epa.gov/region09/waste/sfund/indianbend/index.html</ref> One of the three drinking water wells previously owned by the City of Phoenix and ultimately sold to the City of Scottsdale, tested at 390 ppb TCE when it was closed in 1982.
	(see East Valley Tribune, April 6, 2007, "Feds to Examine Superfund Site" by John Yantis) Some Scottsdale residents who received their water bills from the City of Phoenix throughout the 1960s and 70's were understandably confused as to whether they indeed had been consuming contaminated water when information about the Superfund site was first disseminated. The City of Scottsdale recently updated their website to clarify that the contaminated wells were "in the Scottsdale area" and to delete all references to the levels of TCE discovered when the wells were closed as "trace".<ref>http://www.scottsdaleaz.gov/water/superfund.asp</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>
	A spot was then ultimately chosen to receive and treat the contaminated drinking water known as the Central Groundwater Treatment Facility. Then 1989, as now, this treatment facility (CGTF) is situated on land adjacent to Pima Park and the Siemens facility documented as one of the Potentially Responsible Parties at the corner of Thomas and Pima roads. Close proximity to this park did not appear to enter into Motorola's calculations when asserting that it would save money to remove the carbon air filters in 2007. (See East Valley Tribune, October 5, 2007, "Motorola wants to axe filters at Superfund site" by Ari Cohn)
	Camp Lejeune in North Carolina may be the largest TCE contamination site in the country. Legislation could force the EPA to establish a health advisory and a national public drinking water regulation to limit trichloroethylene.<ref>"Lejeune water contamination bill could force EPA to establish public standard", by Jennifer Hlad in Jacksonville, NC '''''DAILY NEWS''''' , August 10, 2008 http://www.jdnews.com/news/water_58714___article.html/bill_tce.html</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.
	For over twenty years of operation, the US-based multinational Radio Company of America (]) had been pouring toxic wastewater into a well in its Taoyuan, Taiwan facility. The pollution from the plant was not revealed until 1994, when former workers brought it to light. Investigation by the Taiwan Environmental Protection Administration confirmed that RCA had been dumping chlorinated organic solvents into a secret well and caused contamination to the soil and groundwater surrounding the plant site. High levels of TCE tetrachloroethylene (PCE) can be found in groundwater drawn as far as two kilometers from the site. An organization of former RCA employees reports 1375 cancer cases, 216 cancer deaths, and 102 cases of various tumors among its members.<ref>Poisoned RCA Workers Demand Justice And Peace, http://www.cphan.org/libr/poisonedworkers.pdf</ref><ref>"Facing Up to a Dirty Secret", Far Eastern Economic Review, Dec. 12, 2002. http://books.google.com/books?id=K7iouBiOo3cC&pg=PA70&lpg=PA70&dq=RCA%2BTaoyuan&source=web&ots=MVVKzSqJzD&sig=41gfMV5aG6LDRdr7nLnhAU3_nus&hl=
	en&sa=X&oi=book_result&resnum=5&ct=result#PPA68,M1</ref>
			In 2023, the United States ] (EPA) determined that trichloroethylene presents a risk of injury to human health in various uses, including during manufacturing, processing, mixing, ], vapor degreasing, as a lubricant, adhesive, ], cleaning product, and spray. It is dangerous from both inhalation and ] exposure and was most strongly associated with ] effects for acute exposure, as well as ] 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=www.epa.gov |language=en |format=PDF}}</ref> As of June 1, 2023, two U.S. states (] and ]) have acted on the EPA's findings and banned trichloroethylene in all cases but research and development.<ref>{{cite web
	Trichloroethylene is a cleaning solvent that was used to clean military weapons during the ]. There are reports associating exposure to this solvent with ] (Kasarskis EJ et al. Amyotrophic Lateral Sclerosis, 2008 Sep 16:1-7, Clinical aspects of ALS in Gulf War Veterans), and also with a neurologic syndrome resembling ] (Gash DM. et al. Ann Neurol. 2008 Feb;63(2):184-92. Trichloroethylene: Parkinsonism and complex 1 mitochondrial neurotoxicity).
			|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"{{update inline|date=November 2023}} 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>
			==Remediation==
	=== Existing regulation ===
			Recent research has focused on the in-place remediation of trichloroethylene in soil and groundwater using ] instead of removal for off-site treatment and disposal. Naturally occurring ] have been identified with the ability to degrade TCE. '']'' sp. degrade trichloroethylene by reductive dechlorination under anaerobic conditions. Under aerobic conditions, '']'' can co-metabolize TCE. Soil and groundwater contamination by TCE has also been successfully remediated by chemical treatment and extraction. The bacteria '']'' 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 |url-status=dead }}</ref> ] has been reported to be involved in TCE degradation by '']''.<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=978-1566765619|date=1998|pages=142, 144|publisher=CRC Press }}</ref> In some cases, '']'' can convert up to 51% of TCE to CO and {{CO2}}.<ref name="Irvine"/>
			==Society and culture==
	Until recent years, the US Agency for Toxic Substances and Disease Registry (ATSDR) contended that trichloroethylene had little-to-no carcinogenic potential, and was probably a ]&mdash;that is, it acted in concert with other substances to promote the formation of tumors.
			] and ] contamination from industrial discharge including trichloroethylene is a major concern for human health and has precipitated numerous incidents and lawsuits in the United States.
			The 1995 non-fiction book '']'' was written about a lawsuit ('']'') against following the increase in cancer cases after trichloroethylene pollution incidents and it was ].
	Half a dozen state, federal, and international agencies now classify trichloroethylene as a probable carcinogen. The ] considers trichloroethylene a Group 2A carcinogen, indicating that it considers it is probably carcinogenic to humans.<ref>IARC monograph. Vol. 63, p. 75. Last Updated May 20, 1997. Last retrieved June 22, 2007.</ref>
	California EPA regulators consider it a known carcinogen and issued a risk assessment in 1999 that concluded that it was far more toxic than previous scientific studies had shown.
			TCE has been used as a ].<ref> in ''Neurology in Clinical Practice'', Daroff, R. B., Fenichel, G. M., Jankovic, J., Mazziotta, J. C. (2012).</ref> Common methods of taking trichloroethylene recreationally include inhalation from a rag (similar to taking an inhalational anaesthetic) and drinking.<ref name=abuse> Medical Toxicology of Drug Abuse: Synthesized Chemicals and Psychoactive Plants.Barceloux, D. G. (2012).</ref> Most TCE abusers were young people and workers who use the chemical in their workplace. The main reason for abuse is TCE's euphoriant and slight hallucinogenic effect.<ref name=abuse/> Some 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 ]</ref>
	=== Proposed U.S. federal regulation ===
	In 2001, a draft report of the Environmental Protection Agency (EPA) laid the groundwork for tough new standards to limit public exposure to trichloroethylene. The assessment set off a fight between the EPA and the ] (DoD), the ], and ], who appealed directly to the White House. They argued that the EPA had produced junk science, its assumptions were badly flawed, and that evidence exonerating the chemical was ignored.
	The DoD has about 1,400 military properties nationwide that are contaminated with trichloroethylene. Many of these sites are detailed and updated by www.cpeo.org and include a former ammunition plant in the Twin Cities area.<ref>http://www.cpeo.org/milit.html</ref> Twenty three sites in the Energy Department's nuclear weapons complex — including ] in the San Francisco Bay area, and NASA centers, including the ] in ] are reported to have TCE contamination.
	Political appointees in the EPA sided with the Pentagon and agreed to pull back the risk assessment. In 2004, the ] was given a $680,000 contract to study the matter, releasing its report in the summer of 2006. The report has raised more concerns about the health effects of TCE.
	In response to the heightened awareness of environmental toxins such as TCE and the role they may be playing in childhood disease, Sen. Obama proposed S1068, cosponsored by Hillary Clinton and others.<ref>http://www.thomas.gov/cgi-bin/thomas</ref> This legislation aims to inform and protect communities that are threatened with environmental contamination. Sen. Clinton's own bill, S1911, is known as the TCE Reduction Act. This bill was co-sponsored by Sen. Elizabeth Dole (R-North Carolina).
	=== Reduced production and remediation ===
	In recent times, there has been a substantial reduction in the production output of trichloroethylene; alternatives for use in metal degreasing abound, chlorinated aliphatic hydrocarbons being phased out in a large majority of industries due to the potential for irreversible health effects and the legal liability that ensues as a result.
	The U.S. military has virtually eliminated its use of the chemical, purchasing only 11 gallons in 2005.<ref>{{cite news
	|page= 4
	|title= How Environmentalists Lost the Battle Over TCE
	|author= Ralph Vartabedian
	|newspaper= Los Angeles Times
	|date=2006-03-29
	|accessdate=2010-01-25
	|url=http://articles.latimes.com/2006/mar/29/nation/na-toxic29?pg=4
	}}</ref> About 100 tons of it is used annually in the U.S. as of 2006.<ref>{{cite news
	|page= 5
	|title= How Environmentalists Lost the Battle Over TCE
	|author= Ralph Vartabedian
	|newspaper= Los Angeles Times
	|date=2006-03-29
	|accessdate=2010-01-25
	|url=http://articles.latimes.com/2006/mar/29/nation/na-toxic29?pg=5
	}}</ref>
	Recent research has focused on the in-place remediation of trichloroethylene in soil and ground water instead of removal for off-site treatment and disposal. Naturally-occurring bacteria have been identified with the ability to degrade or completely mineralize thrichloroethylene. ''Dehalococcoide'' sp. degrade trichloroethylene by reductive dechlorination under anaerobic conditions. Under aerobic conditions, ''Pseudomonas fluorescence'' can co-metabolize TCE. Soil and ground water contamination by TCE has also been successfully remediated by chemical treatment and extraction.
	=== Cases of TCE contaminated water ===
	*]<ref>http://oaspub.epa.gov/enviro/cerclis_web.description_report?pgm_sys_id=MOD981717036</ref>
	*Minneapolis/St Paul, Minnesota http://www.globalsecurity.org/military/facility/aap-twincities.htm
	*]<ref>http://www.phoenixnewtimes.com/1996-10-24/news/the-pain-of-maryvale/1</ref>
	*], ]<ref>http://www.daytondailynews.com/n/content/oh/story/news/local/2008/09/04/ddn090408behr.html</ref>
	*], ]
	*], ]
	*], ] and ], ]<ref> ] - documentary on the contamination of Shannon</ref> (scientists are using a new genetic technology to prove the link between TCE and a wide spectrum of cancer types for a class action<ref></ref>).
	*], ] (the town from the book/movie ])
	*], ]<ref>{{cite news| url=http://www.cnn.com/2009/HEALTH/09/25/marines.breast.cancer.folo/index.html | work=CNN | title=Poisoned patriots? Stricken Marines seek help with illnesses - CNN.com | accessdate=May 26, 2010 | date=September 25, 2009}}</ref>
	*]<ref></ref>
	*], ]
	*], ] (from the ] ] site), in 2007<ref>http://www.azstarnet.com/allheadlines/212144</ref> and 2008<ref>http://www.azcentral.com/arizonarepublic/local/articles/0116water0117ON.html</ref>
	*], ]<ref>http://news.therecord.com/News/Local/article/271823</ref>
	* ], ] (] supplied the ] with chemicals for ]<ref>http://cfpub.epa.gov/supercpad/SiteProfiles/index.cfm?fuseaction=second.Contams&id=0504619</ref>)
	* ], ]
	* ], ]<ref>http://www.mde.state.md.us/assets/document/Rotorex%20Parcel%20325.pdf</ref>
	* ]<ref></ref>
	* ], ]
	* ], ]
	* ], ] (from U.S. EPA, Region III) <ref>http://www.epa.gov/reg3wcmd/ca/pa/pdf/pad003026903.pdf</ref><ref>http://www.epa.gov/reg3wcmd/ca/pa/pdf/pad003026903.pdf</ref>
	*]
	*]
	*]
	*]<ref>http://www.therecordherald.com/homepage/x2141118807/Homes-with-contaminated-wells-may-get-public-water</ref>
	*]
	*]<ref>http://www.epa.gov/region5superfund/npl/wisconsin/WID980993521.htm</ref>
	*]<ref>http://www.epa.gov/reg3hscd/npl/VAD980829030.htm</ref>
	*]<ref>http://baronandbudd.com/epa_will_provide_access_to_elkhart_indiana_municipal_water_for_lane_street_residents_whose_wells_are_contaminated_by_tce_0</ref>
	*Waterloo, Quebec
	==Media==
	In the John Travolta film ], the case of a TCE-contaminated tannery and town water supply is covered in detail.
	==References==		==References==
	{{reflist|2}}		{{Reflist}}
	==Further reading==		==Further reading==
	* Agency for Toxic Substances and Disease Registry (ATSDR). 1997. Toxicological Profile for Trichloroethylene.		* Agency for Toxic Substances and Disease Registry (ATSDR). 1997.
			* {{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}}
	* Doherty, R.E. 2000. 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. Journal of Environmental Forensics (2000) 1, 83-93.
			* {{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://amp.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.
	* {{cite journal |author=Lipworth L, Tarone RE, McLaughlin JK |title=The epidemiology of renal cell carcinoma |journal=J. Urol. |volume=176 |issue=6 Pt 1 |pages=2353–8 |year=2006 |month=December |pmid=17085101 |doi=10.1016/j.juro.2006.07.130 |url=http://www.jurology.com/article/PIIS0022534706019537}}
			* US National Academy of Sciences (NAS). 2006. Committee on Human Health Risks of Trichloroethylene, National Research Council.
			* US National Toxicology Program (NTP). 2021.
	* U.S. Environmental Protection Agency (USEPA). 2001. Trichloroethylene Health Risk Assessment: Synthesis and Characterization (External Review Draft)
	* U.S. National Academy of Sciences (NAS). 2006. Assessing Human Health Risks of Trichloroethylene - Key Scientific Issues. Committee on Human Health Risks of Trichloroethylene, National Research Council.
	* U.S. National Toxicology Program (NTP). 2005. Trichloroethylene, in the 11th Annual Report of Carcinogens.
	* Comment on Voluntary Scheme for users of Trichloroethylene at
	==External links==		==External links==
			{{commons category}}
	* from Euro Chlor - ECSA (European Chlorinated Solvent Association)
			* – US ] (EPA)
	* U.S. ] (public domain)
			* – Sustainable uses and industry recommendations, ]
	*, National Academy of Sciences
			* – ] (ATSDR), of the US ] (public domain)
	*
			* – US ] (NAS)
	*
			* – US ] (NIH)
	* NIOSH Safety and Health Topic:
			* – US ] (NIOSH)
			{{Pollution}}
	{{General anesthetics}}		{{General anesthetics}}
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