| Tetrachloroethene | |
|---|---|
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| IUPAC name | tetrachloroethene |
| Other names | perchloroethene perchloroethylene perc, PCE |
| Identifiers | |
| CAS number | [127-18-4] |
| EINECS number | |
| RTECS number | KX3850000 |
| SMILES | C(=C(Cl)Cl)(Cl)Cl |
| Properties | |
| Molecular formula | C2Cl4 |
| Molar mass | 165. 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 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) 8 g/mol |
| Appearance | Clear, colorless liquid |
| Density | 1. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 622 g/cm3, liquid |
| Melting point |
−19 °C (254 K) |
| Boiling point |
121. 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 1 °C (394 K) |
| Solubility in water | 0. 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. 015 g/100 ml (20 °C) |
| Viscosity | 0. Viscosity is a measure of the resistance of a Fluid which is being deformed by either Shear stress or Extensional stress. 89 cP at 25 °C |
| Hazards | |
| MSDS | External MSDS |
| MSDS | External MSDS |
| Main hazards | Harmful (Xn), Dangerous for the environment (N) |
| R-phrases | 40-51/53 |
| S-phrases | 23-36/37-61 |
| Flash point | Not flammable |
| Related compounds | |
| Related Related Haloforms | tetrabromoethylene tetraiodoethylene |
| Related compounds | trichloroethylene dichloroethene tetrachloroethane |
| Supplementary data page | |
| Structure and properties |
n, εr, etc. The poise (symbol P pwɑːz is the unit of dynamic Viscosity in the Centimetre gram second system of units. 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 Tetrachloroethylene 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 R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. The flash point of a flammable liquid is the lowest Temperature at which it can form an ignitable mixture in air Trihalomethanes ( THM s are Chemical compounds in which three of the four hydrogen atoms of Methane (CH4 are replaced by Halogen atoms The Chemical compound trichloroethylene is a chlorinated Hydrocarbon commonly used as an industrial Solvent. This page provides supplementary chemical data on Tetrachloroethylene This page provides supplementary chemical data on Tetrachloroethylene 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 data | UV, 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 |
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Tetrachloroethene Cl2C=CCl2 is a manufactured chemical compound that is widely used for the dry cleaning of fabrics (often commonly called dry-cleaning fluid) and for metal-degreasing. This page provides supplementary chemical data on Tetrachloroethylene This page provides supplementary chemical data on Tetrachloroethylene 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. Dry cleaning is any cleaning process for Clothing and Textiles using an organic Solvent rather than Water. It is also used to make other chemicals and is used in some consumer products.
Other names for tetrachloroethene include perchloroethylene, perc, PCE, and tetrachloroethylene. It is a nonflammable liquid at room temperature. Flammability is the ease with which a substance will ignite causing Fire or Combustion. Liquid is one of the principal States of matter. A liquid is a Fluid that has the particles loose and can freely form a distinct surface at the boundaries of Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature It evaporates easily into the air and has a sharp, sweet odor. Evaporation is the process by which Molecules in a Liquid state (e Most people can smell tetrachloroethylene when it is present in the air at a concentration of 1 part per million (1 ppm), although some can smell it at even lower levels.
Michael Faraday first synthesized tetrachloroethene in 1821 by heating hexachloroethane until it decomposed into tetrachloroethene and chlorine. Michael Faraday, FRS ( September 22 1791 – August 25 1867) was an English Hexachloroethane, also known as perchloroethane (PCA C2[[chlorine Cl6]], is a colorless solid at room temperature which is used by the Chlorine (ˈklɔriːn from the Greek word 'χλωρóς' ( khlôros, meaning 'pale green' is the Chemical element with Atomic number 17 and
Contents |
Production
Most tetrachloroethene is produced from ethene via 1,2-dichloroethane. Structure This Hydrocarbon has four Hydrogen Atoms bound to a pair of Carbon atoms that are connected by a Double bond. When 1,2-dichloroethane is heated to 400°C with chlorine, tetrachloroethene is produced by the chemical reaction
ClCH2CH2Cl + 3 Cl2 → Cl2C=CCl2 + 4 HCl
This reaction can be catalyzed by a mixture of potassium chloride and aluminium chloride, or by activated carbon. Chlorine (ˈklɔriːn from the Greek word 'χλωρóς' ( khlôros, meaning 'pale green' is the Chemical element with Atomic number 17 and A chemical reaction is a process that always results in the interconversion of Chemical substances The substance or substances initially involved in a chemical reaction are called Chlorine (ˈklɔriːn from the Greek word 'χλωρóς' ( khlôros, meaning 'pale green' is the Chemical element with Atomic number 17 and Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst 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. Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Trichloroethylene is a major byproduct of the reaction, and since both are salable commercial chemicals, typical industrial practice is to collect both products and then separate them by distillation. The Chemical compound trichloroethylene is a chlorinated Hydrocarbon commonly used as an industrial Solvent. Distillation is a method of separating Mixtures based on differences in their volatilities in a boiling liquid mixture
Tetrachlorethene can also be made from a mixture of partially chlorinated light hydrocarbons that would otherwise be hazardous waste products of several chemical processes. In Organic chemistry, a hydrocarbon is an Organic compound consisting entirely of Hydrogen and Carbon. When these compounds are heated in the presence of excess chlorine, they are converted to a mixture of tetrachloroethene, carbon tetrachloride, and hydrogen chloride. Carbon tetrachloride, also known by many other names (see Table is the Organic compound with the formula CCl4
Uses
Most applications of tetrachloroethene use it for its solvent properties. A solvent is a liquid or gas that dissolves a solid liquid or gaseous Solute, resulting in a Solution. Most organic materials dissolve in tetrachloroethene. Organic chemistry is a discipline within Chemistry which involves the scientific study of the structure properties composition reactions, and preparation It is the most widely used solvent in dry cleaning. Dry cleaning is any cleaning process for Clothing and Textiles using an organic Solvent rather than Water. It is also used to degrease metal parts in the automotive and other metalworking industries. It appears in a few consumer products including paint strippers and spot removers. Paint stripper, or paint remover, is the generic name given to Solvent mixtures designed to remove Paint and other finishes and also to clean the underlying
In the early 20th century, tetrachloroethene was the most effective available treatment for hookworm. The twentieth century of the Common Era began on The hookworm is a parasitic Nematode worm that lives in the Small intestine of its host which may be a Mammal such as a Dog,
Tetrachloroethene is also extensively used as an intermediate in the manufacture of refrigerants such as HFC-134a. A refrigerant is a compound used in a heat cycle that undergoes a Phase change from a Gas to a Liquid and back
Health and safety
Like many chlorinated hydrocarbons, tetrachloroethene is a central nervous system depressant, and inhaling its vapors (particularly in closed, poorly ventilated areas) can cause dizziness, headache, sleepiness, confusion, nausea, difficulty in speaking and walking, unconsciousness, and death. Applications The simplest form of organochlorides are chlorinated Hydrocarbons These consist of simple Hydrocarbons in which one or more hydrogen atoms have In Vertebrates the central nervous system ( CNS) is the part of the Nervous system which is enclosed in the Meninges. A headache ( cephalalgia in medical terminology is a condition of pain in the Head; sometimes Neck or upper back pain may also be interpreted Nausea ( Latin: Nausea, Greek:, " Sea-sickness " also called wamble) is the sensation of unease and discomfort
After repeated or extended skin contact, tetrachloroethene may dissolve fats from the skin, resulting in severe skin irritation in work environments where people have been exposed to high concentrations.
Tetrachloroethene is a common soil contaminant. Soil contamination is caused by the presence of man-made chemicals or other alteration in the natural soil environment Such contamination most often results from spillage, overfilling, sewer leakage, or the illegal disposal into UIC wells (e. g. septic systems, drywells) at commercial dry cleaning facilities. Because of the mobility of PCE in groundwater, its toxicity at low levels, and its density (which causes it to sink below the water table), cleanup activities tend to be especially problematic compared to cleanups of oil spills. Toxicity is the degree to which a substance is able to damage an exposed organism The water table is the level at which the ground water pressure is equal to Atmospheric pressure.
In industry, most workers are exposed to levels lower than those causing obvious nervous system effects. The health effects of tetrachloroethene at levels typically encountered in occupational or environmental exposures have not been well established.
Results from some studies suggest that women who work in dry cleaning industries where exposures to tetrachloroethene can be quite high may have more menstrual problems and spontaneous abortions than women who are not exposed. See also "Mensuration" a term sometimes used to describe Measurement, particularly in the context of Forestry. Miscarriage or spontaneous abortion is the natural or spontaneous end of a Pregnancy at a stage where the embryo or fetus is incapable of surviving generally defined However, it is not known if tetrachloroethene was responsible for these problems because other possible causes were not considered.
Results of animal studies, conducted with amounts much higher than those that most people are exposed to, show that tetrachloroethene can cause liver and kidney damage. The liver is a vital organ in the human body and is present in Vertebrates and some other animals The kidneys are complicated organs that have numerous biological roles Exposure to very high levels of tetrachloroethene can be toxic to the unborn pups of pregnant rats and mice. Changes in behavior were observed in the offspring of rats that breathed high levels of the chemical while they were pregnant.
The International Agency for Research on Cancer has classified tetrachloroethene as a Group 2A carcinogen, which means that 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 The term carcinogen refers to any substance Radionuclide or radiation that is an agent directly involved in the promotion of Cancer or in the fatation of its propagation [1]
Under a high temperature flame such as those produced by a TIG torch or other welding arcs, Phosgene gas is produced. Phosgene is the Chemical compound with the formula COCl2 This colorless gas gained infamy as a Chemical weapon during World War I The gas attacks the lining of the lungs, leading to suffocation. Care should be taken to allow the solvent to completely evaporate when welding porous castings recently cleaned with tetrachloroethene.
Contamination at U. S. Marine base
On June 12, 2007, the U. Events 1381 - Peasants' Revolt: in England, rebels arrive at Blackheath. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. S. Centers for Disease Control and Prevention reported that as many as 75,000 people may have drunk water contaminated with tetrachloroethene at Camp Lejeune in North Carolina. The Centers for Disease Control and Prevention (or CDC) is an agency of the United States Department of Health and Human Services based in unincorporated 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 The affected area is the Tarawa Terrace family housing area, and the contamination lasted from November 1957 through February 1987, the agency said. Year 1957 ( MCMLVII) was a Common year starting on Tuesday (link displays the 1957 Gregorian calendar) Year 1987 ( MCMLXXXVII) was a Common year starting on Thursday (link displays 1987 Gregorian calendar) An off-base dry cleaners leaked a maximum concentration of 200 micrograms per liter of the fluid into a septic system near the housing area's well. Dry cleaning is any cleaning process for Clothing and Textiles using an organic Solvent rather than Water. Description A septic tank generally consists of tanks between the size of 1000 and 2000 gallons (4000 - 7500 litres which is connected to an inlet wastewater pipe at one end and [2]
Testing for PCE
One method of testing for tetrachloroethene exposure is to measure the amount of the chemical in the breath, much the same way breath-alcohol measurements are used to determine the amount of alcohol in the blood.
Because it is stored in the body's fat and slowly released into the bloodstream, tetrachloroethene can be detected in the breath for weeks following a heavy exposure.
Tetrachloroethene and trichloroacetic acid (TCA), a breakdown product of tetrachloroethene, can be detected in the blood. Trichloroacetic acid (also known as trichloroethanoic acid) is an analogue of Acetic acid in which the three Hydrogen atoms of the Methyl Blood is a specialized Bodily fluid that delivers necessary substances to the body's cells such as nutrients and oxygen—and transports Waste products These tests are relatively simple to perform. These tests are not available at most doctors' offices, but can be performed at laboratories with the necessary equipment. Because exposure to other chemicals can produce the same breakdown products in the urine and blood, the tests for breakdown products cannot determine if one has been exposed to tetrachloroethene or the other chemicals. Urine is a liquid waste product of the body secreted by the Kidneys by a process of filtration from Blood and Excreted through the Urethra.
Popular culture
- Tetrachloroethene contamination was used as a plot focus in a story arc of the TV show Ghostwriter. Ghostwriter is a television series co-produced by the Children's Television Workshop (now known as Sesame Workshop) and the BBC
- It has been featured in the episode Foothold (season 3) of Stargate SG1 where one of the side effects was hallucinations and paranoia. Season three of Stargate SG-1, an American - Canadian Television series, began airing on June 25, 1999 on A hallucination, in the broadest sense is a Perception in the absence of a stimulus. Paranoia is a disturbed thought process characterized by excessive Anxiety or Fear, often to the point of Irrationality and Delusion.
- The health risks of tetrachloroethene and trichloroethene are discussed in A Civil Action, which involves a Woburn, Massachusetts, lawsuit where a cluster of leukemia developed, arguably due to high perc levels. A Civil Action is a 1998 film starring John Travolta (as plaintiff's attorney Jan Schlichtmann) and Robert Duvall, based on
References
- ^ IARC monograph. "Tetrachloroethylene" Vol. 63, p. 159. Last Updated May 20, 1997. Last retrieved June 22, 2007.
- ^ "Marines drank tainted water for 30 years: CDC", Reuters, Jun 12, 2007. This article is primarily about Reuters prior to its 2008 merger with Thomson
Further reading
Agency for Toxic Substances and Disease Registry (ATSDR). 1997. Toxicological Profile for Tetrachloroethene. 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 1 - Historical Background; Carbon Tetrachloride and Tetrachloroethylene. Journal of Environmental Forensics (2000) 1, 69-81. link
External links
- Tetrachloroethylene MSDS
- Australian National Pollutant Inventory (NPI) page
- "Toxic Fumes May Have Made Gunman Snap", by Julian Kesner, New York Daily News, April 20, 2007.
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