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Trichloroethylene
IUPAC nametrichloroethene
Other names1,1,2-Trichloroethene, 1,1-Dichloro-2-Chloroethylene, 1-Chloro-2,2-Dichloroethylene, Acetylene Trichloride, TCE, Trethylene, Triclene, Tri, Trimar, Trilene
Identifiers
AbbreviationsTCE
CAS number[79-01-6]
EINECS number201-61-04
RTECS numberKX4550000
SMILESClC=C(Cl)Cl
InChI1/C2HCl3/c3-1-2(4)5/h1H
Properties
Molecular formulaC2HCl3
Molar mass131. IUPAC Nomenclature is a system of naming Chemical compounds and of describing the science of Chemistry in general CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to The EINECS number (for European Inventory of Existing Chemical Substances) is a registry number given to each Chemical substance commercially available in the Registry of Toxic Effects of Chemical Substances ( RTECS) is a Database of Toxicity information compiled from the open scientific literature without reference The IUPAC International Chemical Identifier ( InChI, pronounced "INchee" is a textual Identifier for Chemical substances designed to provide a A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) 39 g mol-1
AppearanceColorless liquid
Density1. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 46 g/cm3 (liquid) at 20°C
Melting point

200 K (−73 °C)

Boiling point

360 K (87 °C)

Solubility in water0. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Water is a common Chemical substance that is essential for the survival of all known forms of Life. 1 g/100 cm3 at 25°C
Solubilityether, ethanol, chloroform
Refractive index (nD)1. Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Diethyl ether, also known as ether and ethoxyethane, is a clear colorless and highly Flammable liquid with a low Boiling point and a Chloroform, also known as trichloromethane and methyl trichloride, is a Chemical compound with formula C[[Hydrogen H]] Cl The refractive index (or index of Refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves is reduced inside the medium 4777 at 19. 8°C
Hazards
MSDSExternal MSDS
MSDSMallinckrodt Baker
Main hazardsHarmful if swallowed or inhaled. A material safety data sheet ( MSDS) is a form containing data regarding the properties of a particular substance This page provides supplementary chemical data on Trichloroethylene A material safety data sheet ( MSDS) is a form containing data regarding the properties of a particular substance Occupational safety and health is a cross-disciplinary area concerned with protecting the Safety, Health and welfare of people engaged in
NFPA 704
1
2
0
 
Autoignition
temperature		420°C
Related compounds
Related vinyl halidevinyl chloride
Related compoundschloroform
1,1,1-Trichloroethane
1,1,2-Trichloroethane
Supplementary data page
Structure and
properties		n, εr, etc. Symbolism The four divisions are typically color-coded with blue indicating level of Health Hazard, red indicating The autoignition temperature or kindling point of a substance is the lowest temperature at which it will spontaneously ignite in a normal atmosphere without an external A vinyl halide in Chemistry is any Alkene with at least one Halide Substituent bonded directly on one of the unsaturated carbons Vinyl chloride is the Organic compound with the formula CH2CHCl Chloroform, also known as trichloromethane and methyl trichloride, is a Chemical compound with formula C[[Hydrogen H]] Cl This page provides supplementary chemical data on Trichloroethylene This page provides supplementary chemical data on Trichloroethylene The refractive index (or index of Refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves is reduced inside the medium Measurement The relative static permittivity εr can be measured for static Electric fields as follows first the Capacitance of a test
Thermodynamic
data		Phase behaviour
Solid, liquid, gas
Spectral dataUV, IR, NMR, MS
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references

The chemical compound trichloroethylene is a chlorinated hydrocarbon commonly used as an industrial solvent. This page provides supplementary chemical data on Trichloroethylene This page provides supplementary chemical data on Trichloroethylene Ultraviolet-visible spectroscopy or ultraviolet-visible spectrophotometry ( UV/ VIS) involves the Spectroscopy of Photons in the UV-visible Infrared spectroscopy (IR spectroscopy is the subset of Spectroscopy that deals with the Infrared region of the Electromagnetic spectrum. Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy, is the name given to a technique which exploits the magnetic properties of certain nuclei Mass spectrometry is an analytical technique that identifies the chemical composition of a compound or sample based on the Mass-to-charge ratio of charged particles In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly A chemical compound is a substance consisting of two or more different elements chemically bonded together in a fixed proportion by Mass. Chlorine (ˈklɔriːn from the Greek word 'χλωρóς' ( khlôros, meaning 'pale green' is the Chemical element with Atomic number 17 and In Organic chemistry, a hydrocarbon is an Organic compound consisting entirely of Hydrogen and Carbon. A solvent is a liquid or gas that dissolves a solid liquid or gaseous Solute, resulting in a Solution. It is a clear non-flammable liquid with a sweet smell.

Its IUPAC name is trichloroethene. The International Union of Pure and Applied Chemistry ( IUPAC) (aɪjuːpæk or ay-yoo-pec) is an international Non-governmental organization In industry, it is informally referred to by the abbreviations TCE, Trike and tri, and it is sold under a variety of trade names. In addition to its industrial uses, trichloroethylene was used from about 1930 as a volatile anesthetic and analgesic in millions of patients, before its toxic properties were realized.

Contents

History

Pioneered by Imperial Chemical Industries in Britain, its development was hailed as a revolution: lacking the great hepatotoxic liability of chloroform and the unpleasant pungency and flammability of ether, it nonetheless had several pitfalls, including the sensitization of the myocardium to epinephrine, potentially acting in an arrhythmogenic manner. Imperial Chemical Industries ( ICI) is a British chemical subsidiary of a Dutch conglomerate and one of the largest chemical producers Drug metabolism in liver The human body identifies almost all drugs as foreign substances (i Chloroform, also known as trichloromethane and methyl trichloride, is a Chemical compound with formula C[[Hydrogen H]] Cl Ether is a class of Organic compounds which contain an ether group — an Oxygen Atom connected to two (substituted Alkyl Myocardium is the muscular tissue of the Heart. Relationship to other layers The other tissues of the heart are the Endocardium Dysrhythmia redirects here For the American band see Dysrhythmia (band. Its low volatility demanded the employment of carefully regulated heat in its vaporization. Research demonstrating its transient elevation of serum hepatic enzymes raised concerns regarding its hepatotoxic potential. Several deaths occurred as a result, though the incidence was comparable to that of halothane hepatitis. Halothane vapour (or Fluothane) is an inhalational General anaesthetic. Incompatibility with soda lime (the CO2 adsorbent utilized in closed-circuit, low-flow rebreathing systems) was also a concern. TCE was readily decomposed into 1,2-dichloroacetylene, a neurotoxic compound potentially responsible for its hepatotoxic potential, though its metabolite trichloroacetic acid is more probably the etiological source of the latter. Halothane usurped a great portion of its market in 1956, with its total abandonment not achieved until the 1980s, when its use as an analgesic in obstetrics was implicated in fetal death. Halothane vapour (or Fluothane) is an inhalational General anaesthetic. Concerns of its carcinogenic potential were raised simultaneously.

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 process in Europe as the chemical was classified as a carcinogen carrying an R45 risk phrase. Many alternatives are being promoted such as Ensolv and Leksol, however each of these is based on nPropyl Bromide which carries an R60 risk phrase and they would not be a legally acceptable substitute.

Production

Prior to the early 1970s, most trichloroethylene was produced in a two-step process from acetylene. Acetylene ( IUPAC name ethyne), C2H2 is a Hydrocarbon belonging to the group of Alkynes It is the simplest of all alkynes First, acetylene was treated with chlorine using a ferric chloride catalyst at 90 °C to produce 1,1,2,2-tetrachloroethane according to the chemical equation

HC≡CH + 2 Cl2 → Cl2CHCHCl2

The 1,1,2,2-tetrachloroethane is then dehydrochlorinated to give trichloroethylene. Iron chloride redirects here For Iron(II chloride see Iron(II chloride. Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst A chemical equation is a symbolic representation of a Chemical reaction. Acetylene ( IUPAC name ethyne), C2H2 is a Hydrocarbon belonging to the group of Alkynes It is the simplest of all alkynes Chlorine (ˈklɔriːn from the Greek word 'χλωρóς' ( khlôros, meaning 'pale green' is the Chemical element with Atomic number 17 and This can either be accomplished with an aqueous solution of calcium hydroxide

2 Cl2CHCHCl2 + Ca(OH)2 → 2 ClCH=CCl2 + CaCl2 + 2 H2O

or in the vapor phase by heating it to 300-500°C on a barium chloride or calcium chloride catalyst

Cl2CHCHCl2 → ClCH=CCl2 + HCl

Today, however, most trichloroethylene is produced from ethylene. Calcium hydroxide, traditionally called slaked lime, hydrated lime, or pickling lime, is a Chemical compound with the chemical formula Calcium hydroxide, traditionally called slaked lime, hydrated lime, or pickling lime, is a Chemical compound with the chemical formula Calcium chloride (CaCl2 is an ionic compound of Calcium and Chlorine. Barium Chloride is the ionic Chemical compound with the formula BaCl2 Calcium chloride (CaCl2 is an ionic compound of Calcium and Chlorine. Hydrochloric acid is the Solution of Hydrogen chloride ( H[[Chlorine Cl]] in water Structure This Hydrocarbon has four Hydrogen Atoms bound to a pair of Carbon atoms that are connected by a Double bond. First, ethylene is chlorinated over a ferric chloride catalyst to produce 1,2-dichloroethane. Iron chloride redirects here For Iron(II chloride see Iron(II chloride.

CH2=CH2 + Cl2 → ClCH2CH2Cl

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

ClCH2CH2Cl + 2 Cl2 → ClCH=CCl2 + 3 HCl

This reaction can be catalyzed by a variety of substances. Structure This Hydrocarbon has four Hydrogen Atoms bound to a pair of Carbon atoms that are connected by a Double bond. The most commonly used catalyst is a mixture of potassium chloride and aluminum chloride. The Chemical compound potassium chloride (KCl is a Metal Halide salt composed of Potassium and Chlorine. Aluminium chloride (AlCl3 is a compound of Aluminium and Chlorine. However, various forms of porous carbon can also be used. Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 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. Tetrachloroethylene, also known under its systematic name tetrachloroethene and as perchloroethylene, perchloroethene, perc, and PCE Typically, trichloroethylene and tetrachloroethylene are collected together and then separated by distillation. Distillation is a method of separating Mixtures based on differences in their volatilities in a boiling liquid mixture

Uses

Trichloroethylene is an effective solvent for a variety of organic materials. A solvent is a liquid or gas that dissolves a solid liquid or gaseous Solute, resulting in a Solution. Organic chemistry is a discipline within Chemistry which involves the scientific study of the structure properties composition reactions, and preparation When it was first widely produced in the 1920s, its major use was to extract vegetable oils from plant materials such as soy, coconut, and palm. The Coconut Palm ( Cocos nucifera) is a member of the Family Arecaceae (palm family Arecaceae or Palmae (also known by the name Palmaceae, which is taxonomically invalid or commonly palm tree) the palm family is a family of Flowering Other uses in the food industry included coffee decaffeination and the preparation of flavoring extracts from hops and spices. CoFFEE is an Open source Software for computer supported collaborative learning (CSCL in a digital classroom Decaffeination is the act of removing Caffeine from coffee beans, mate, Cocoa, Tea leaves and other caffeine-containing materials Hops are the female Flower cones of the hop plant ( Humulus lupulus) A spice is a dried Seed, Fruit, Root, Bark or vegetative substance used in Nutritionally insignificant quantities as a Food additive It was also used as a dry cleaning solvent, although tetrachloroethylene (also known as perchloroethylene) surpassed it in this role in the 1950s. Dry cleaning is any cleaning process for Clothing and Textiles using an organic Solvent rather than Water. Tetrachloroethylene, also known under its systematic name tetrachloroethene and as perchloroethylene, perchloroethene, perc, and PCE

Trichloroethylene has been widely used as a degreaser for metal parts. In the late 1950s, the demand for trichloroethylene as a degreaser began to decline in favor of the less toxic 1,1,1-trichloroethane. Another problem with trichloroethylene is that it's just too good a solvent in many mechanical applications, as it easily will strip many paints almost instantly and dissolves some plastics. However, 1,1,1-trichloroethane production has been phased out in most of the world under the terms of the Montreal Protocol, and as a result trichloroethylene has experienced a resurgence in use. For other similarly-named agreements see Montreal Convention (disambiguation. It has also been used for drying out the last bit of water for production of 100% ethanol.

Trichloroethylene (Trimar and Trilene) was used as a volatile gas anesthetic from the 1930s through the 1960s in Europe and North America. Supplanting chloroform and ether for a significant period of time, trichloroethylene demonstrated superior efficacy in induction times and cost-effectiveness. Chloroform, also known as trichloromethane and methyl trichloride, is a Chemical compound with formula C[[Hydrogen H]] Cl Diethyl ether, also known as ether and ethoxyethane, is a clear colorless and highly Flammable liquid with a low Boiling point and a It retained use in other locations well into the 1990s. It was known for its favorable analgesic properties. Induction of general anesthesia was accomplished by administering up to 1%(v/v) vapor. Equilibration would often result in patient levels of 0. 1 to 0. 5% vapor. Many patients were given Trilene inhalers to self administer analgesia, especially in obstetrical labor. The number of patients exposed to these high levels of trichloroethylene is difficult to know, but is certainly well into the millions.

Chemical instability

Although it has proven useful as a metal degreaser, trichloroethylene itself is unstable in the presence of metal over prolonged exposure. As early as 1961, this phenomenon was clearly recognized by the manufacturing industry, since an additive was instilled in the commercial formulation of trichloroethylene. The reactive instability is accentuated by higher temperatures, so that the search for stabilizing additives is conducted by heating trichloroethylene to its boiling point in a reflux condenser and observing decomposition. In a Laboratory, a condenser is a piece of Laboratory glassware used to cool hot vapors or liquids The first widely used stabilizing additive was dioxane; however, its use was patented by Dow Chemical Company and could not be used by other manufacturers. The Dow Chemical Company () is an American Multinational corporation headquartered in Midland Michigan. Considerable research took place in the 1960s to develop alternative stabilizers for trichlorethylene. The principal family of chemicals that showed promise was the ketone family, such as methyl ethyl ketone. A ketone (pronounced as key tone) is either the Functional group characterized by a Carbonyl group (O=C linked to two other Carbon atoms or Butanone is a manufactured organic chemical. It is a colorless liquid with a sharp sweet butterscotch odor reminiscent of Acetone. Considerable research was conducted at Frontier Chemical Company, Wichita, Kansas on this class of ketones using reflux condensation experiments. Wichita (ˈwɪtʃɪtaː is the most populous City in the US state of Kansas, and the county seat of Sedgwick County. This article is about using reflux in chemical engineering and chemistry Condensation is the change of the physical state of aggregation (or simply state of matter from gaseous phase into liquid phase

Physiological effects

When inhaled, trichloroethylene, as with any anesthetic gas, depresses the central nervous system. In Vertebrates the central nervous system ( CNS) is the part of the Nervous system which is enclosed in the Meninges. Its symptoms are similar to those of alcohol intoxication, beginning with headache, dizziness, and confusion and progressing with increasing exposure to unconsciousness [1]. Intoxication is the state of being affected by one or more psychoactive drugs. Respiratory and circulatory depression from any anesthetic can result in death if administration is not carefully controlled. As mentioned above, cardiac sensitization to catecholamines such as epinephrine can result in dangerous cardiac arrhythmias. Caution should be exercised anywhere a high concentration of trichloroethylene vapors may be present; the drug can desensitize the nose to its scent, and it is possible to unknowingly inhale harmful or lethal amounts of the vapor.

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 [2]. Over time, occupational exposure limits on trichloroethylene have tightened, resulting in more stringent ventilation controls and personal protective equipment use by workers. The tightening of occupational exposure limits and increased need for worker protection in part contributed to the substitution of other lower toxicity chemicals for trichloroethylene in solvent cleaning and degreasing.

The carcinogenicity of trichloroethylene was first evaluated in laboratory animals in the 1970s. Cancer bioassays performed by the National Cancer Institute (later the National Toxicology Program) showed that exposure to trichloroethylene is carcinogenic in animals, producing liver cancer in mice, and kidney cancer in rats [3][4]. The National Cancer Institute (NCI is part of the United States Federal government's National Institutes of Health. The United States Department of Health and Human Services ( HHS) is a Cabinet department of the United States government with the goal of protecting Numerous epidemiological studies have been conducted on trichloroethylene exposure in the workplace, with differing opinions regarding the strength of evidence between trichloroethylene and human cancer. Recent studies on the mechanisms of carcinogenicity have shown that metabolism of trichloroethylene in the liver produces metabolites (such as trichloroacetic acid and dichloroacetic acid, which are responsible for liver tumors in mice) that are the ultimate carcinogens in laboratory animals. Other studies using physiologically-based pharmacokinetic (PBPK) modeling, have examined the similarities and differences in metabolism between humans and laboratory animals, to better understand the relationship between carcinogenicity observed in laboratory animals and human cancer risks. Physiologically-based pharmacokinetic modeling ( PBPK) is a Mathematical modeling technique for prediction of the absorption distribution metabolization and excretion 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. [1]

One recent review of the epidemiology of kidney cancer rated cigarette smoking and obesity as more important risk factors for kidney cancer than exposure to solvents such as trichloroethylene. "Kidney Cancer" redirects here For Wilms' Tumor/Nephroblastoma see Wilms' tumor. [2] In contrast, the most recent overall assessment of human health risks associated with trichloroethylene states, "[t]here is concordance between animal and human studies, which supports the conclusion that trichloroethylene is a potential kidney carcinogen". [3] 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. However the NAS also concluded that higher levels of exposure, such as workplace exposure, or locations with significant environmental contamination, might be associated with a liver cancer risk in humans.

Recent studies in laboratory animals and observations in human populations suggest that exposure to trichloroethylene might be associated with congenital heart defects (J Am Coll Cardiol. 1990 Jul;16(1):155-64. ; J Am Coll Cardiol. 1993 May;21(6):1466-72; Toxicol Sci. 2000 Jan;53(1):109-17; Birth Defects Res A Clin Mol Teratol. 2003 Jul;67(7):488-95; Environ Health Perspect. 2006 Jun;114(6):842-7). While it is not clear what levels of exposure are associated with cardiac defects in humans, there is consistency between the cadiac defects observed in studies of communities exposed to trichloroethylene contamination in groundwater, and the effects observed in laboratory animals. Trichloroethylene can also affect the fertility of males and females in laboratory animals, but the relevance of these findings to humans is not clear.

The health risks of trichloroethylene have been studied extensively. The U.S. Environmental Protection Agency (EPA) sponsored a "state of the science" review of the health effects associated with exposure to trichloroethylene. [4] Based on this review, the EPA published a risk assessment that concluded trichloroethylene posed a more significant human health risk than previous studies had indicated. EPA's report provoked considerable debate about the quality of evidence describing the health risks of trichloroethylene, and the methods used to assess that evidence. In 2004, an interagency group composed of the EPA, Department of Defense, Department of Energy, and the National Aeronautics and Space Administration requested the National Academy of Sciences (NAS) to provide independent guidance on the scientific issues related regarding trichloroethylene health risks. The United States Department of Defense ( DOD or DoD) is the federal department charged with coordinating and supervising all agencies and functions of the government The United States Department of Energy ( DOE) is a Cabinet -level department of the United States government responsible for energy policy The National Aeronautics and Space Administration ( NASA, ˈnæsə is an agency of the United States government, responsible for the nation's public space program The National Academy of Sciences (NAS is a corporation in the United States whose members serve Pro bono as "advisers to the nation on science The NAS report 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. [5]

Human exposure

Human exposure to trichloroethylene is potentially widespread. It is a common contaminant in soil and groundwater at hundreds of waste sites across the United States. Some are exposed to trichloroethylene through contaminated drinking water [5](P. 17). Others are potentially exposed through inhalation of vapor from contaminated soil or groundwater entering nearby buildings. Tens of thousands of workers are potentially exposed to trichloroethylene used as a degreasing and cleaning chemical. Other exposures have occurred through the long-term use of trichloroethylene as a surgical anesthetic.

TCE was first detected in groundwater in 1977, and is one of the most frequently detected contaminants in groundwater in the U. S. Up to 34 percent 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 ug/L. 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. Trichloroethylene has been detected in 852 Superfund sites across the United States,[6] according to the Agency for Toxic Substances and Disease Registry (ATSDR). The United States Agency for Toxic Substances and Disease Registry, ( ATSDR) is an agency for the U

Existing regulation

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 co-carcinogen—that is, it acted in concert with other substances to promote the formation of tumors.

Half a dozen state, federal, and international agencies now classify trichloroethylene as a probable carcinogen. The International Agency for Research on Cancer considers trichloroethylene a Group 2A carcinogen, indicating that it considers it is probably carcinogenic to humans. The International Agency for Research on Cancer ( IARC, or CIRC in its French Acronym) is an intergovernmental agency forming part of the World Health [7] 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.

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 Department of Defense (DoD), the Department of Energy, and NASA, who appealed directly to the White House. The United States Department of Defense ( DOD or DoD) is the federal department charged with coordinating and supervising all agencies and functions of the government The United States Department of Energy ( DOE) is a Cabinet -level department of the United States government responsible for energy policy The National Aeronautics and Space Administration ( NASA, ˈnæsə is an agency of the United States government, responsible for the nation's public space program 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 polluted with trichloroethylene. The chemical has contaminated 23 sites in the Energy Department's nuclear weapons complex — including Lawrence Livermore National Laboratory in the San Francisco Bay area, and NASA centers, including the Jet Propulsion Laboratory in La Cañada Flintridge. The Lawrence Livermore National Laboratory ( LLNL) in Livermore California is a scientific research laboratory founded by the University of California in 1952 La Cañada Flintridge is a city in Los Angeles County, California, United States.

High-level political appointees in the EPA — notably research director Paul Gilman — sided with the Pentagon and agreed to pull back the risk assessment. In 2004, the National Academy of Sciences was given a a $680,000 contract to study the matter, releasing its report in the summer of 2006. The National Academy of Sciences (NAS is a corporation in the United States whose members serve Pro bono as "advisers to the nation on science The report has raised greater concern about the adverse health effects of TCE, opening up the debate for better regulation.

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. About 100 tons of it is used annually in the U. S. as of 2006.

Recent research has focused on aerobic degradation pathways in order to reduce environmental pollution through the use of genetically modified bacteria. Pollution is the introduction of contaminants into an environment that causes instability disorder harm or discomfort to the physical systems or living organisms they are in Genetic engineering, Recombinant DNA technology, genetic modification/manipulation (GM and gene splicing are terms that apply to the direct Limited success has been attained thus far; the intended application is for treatment and detoxification of industrial wastewater. For other uses of this term see Industry (disambiguation An industry (from Latin industrius, "diligent industrious" Distinguish from Wastwater (a lake in the Lake District in northwest England

Cases of TCE contaminated water

References

  1. ^ http://ntp.niehs.nih.gov/index.cfm?objectid=72016262-BDB7-CEBA-FA60E922B18C2540/
  2. ^ Elsevier
  3. ^ Assessing the Human Health Risks of Trichloroethylene: Key Scientific Issues
  4. ^ EHP Supplement: Volume 108 (Supplement 2) May 2000
  5. ^ Assessing the Human Health Risks of Trichloroethylene: Key Scientific Issues
  6. ^ ATSDR - ToxFAQs™: Trichloroethylene (TCE)
  7. ^ IARC monograph. Wichita (ˈwɪtʃɪtaː is the most populous City in the US state of Kansas, and the county seat of Sedgwick County. Kansas ( is a Midwestern state in the central region of the United States of America, an area often referred to as the American " The city of Shannon was born in December of 1846 of a dismemberment of the territory of Saint-Catherine-de-Portneuf, following protests of this part of the population against Quebec (kwɨˈbɛk Quebec (kwɨˈbɛk The Commonwealth of Massachusetts ( is a state located in the New England region of the northeastern United States. A Civil Action is a 1998 film starring John Travolta (as plaintiff's attorney Jan Schlichtmann) and Robert Duvall, based on Marine Corps Base Camp Lejeune is near Jacksonville North Carolina, on the Atlantic seaboard of the United States. North Carolina ( is a state located on the Atlantic Seaboard in the southeastern United States Lisle is a village in DuPage County, Illinois, United States. The State of Illinois ( roughly ill-i-NOY is a state of the United States of America, the 21st to be admitted to the Union. Scottsdale ( O'odham Vaṣai S-vaṣonĭ; Yaqui Eskatel) is a city in the eastern part of Maricopa County, Arizona, The State of Arizona ( is a state located in the southwestern region of the United States. The Indian Bend Wash area is a Superfund cleanup site in Scottsdale and Tempe Arizona. Superfund is the common name for the United States environmental policy officially known as the Comprehensive Environmental Response Compensation and Liability Act Cambridge ( 2006 population 124371 is a city located on the Grand River and Speed River Ontario (ɒnˈtɛrioʊ is a province located in the central part of Canada, the largest by population and second largest after Quebec Salem is a city in northern Columbiana County and extreme southern Mahoning County, Ohio, United States. Ohio ( is a Midwestern state of the United States. As part of the Great Lakes region, Ohio has long been a cultural and geographical crossroads The United States Army is a military organization whose primary mission is to "provide necessary forces and capabilities. Agent Orange is the code name for a powerful Herbicide and Defoliant used by the U Tucson (ˈtuːsɒn is the seat of Pima County Arizona, United States, located 118 miles (188 km) southeast The State of Arizona ( is a state located in the southwestern region of the United States. Walkersville is a town in Frederick County, Maryland, United States. Victor is a Town in Ontario County, New York, USA. The population was 9977 at the 2000 census New York ( is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous Salina (pronounced /səˈlaɪnə/) is a city in and the County seat of Saline County, Kansas, United States. Kansas ( is a Midwestern state in the central region of the United States of America, an area often referred to as the American " "TRICHLOROETHYLENE" Vol. 63, p. 75. Last Updated May 20, 1997. Last retrieved Jun 22, 2007.

Further reading

Agency for Toxic Substances and Disease Registry (ATSDR). 1997. Toxicological Profile for Trichloroethylene. link

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. link

Lipworth, L. , R. E. Tarone and J. K. McLaughlin. 2006. The epidemiology of renal cell carcinoma. Journal of Urology. 176(6): 2353-2358. link

U. S. Environmental Protection Agency (USEPA). 2001. Trichloroethylene Health Risk Assessment: Synthesis and Characterization (External Review Draft) link

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. link

U. S. National Toxicology Program (NTP). 2005. Trichloroethylene, in the 11th Annual Report of Carcinogens. link

Comment on Voluntary Scheme for users of Trichloroethylene at www. ensolv-europe. com

External links


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