Names | |
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IUPAC name decachloropentacyclo[5.3.0.02.6.03.9.04.8]decan-5-one [1] | |
Other names Chlordecone Clordecone Merex CAS name: 1,1a,3,3a,4,5,5,5a,5b,6-decachlorooctahydro-1,3,4-metheno-2H-cyclobuta[cd]pentalen-2-one | |
Identifiers | |
3D model (JSmol) | |
ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.005.093 |
EC Number |
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KEGG | |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C10Cl10O | |
Molar mass | 490.633 g/mol |
Appearance | tan to white crystalline solid |
Odor | odorless |
Density | 1.6 g/cm3 |
Melting point | 349 °C (660 °F; 622 K) (decomposes) |
0.27 g/100 mL | |
Solubility | soluble in acetone, ketone, acetic acid slightly soluble in benzene, hexane |
log P | 5.41 |
Vapor pressure | 3.10−7 kPa |
Thermochemistry | |
Std molar entropy (S⦵298) | 764 J/K mol |
Std enthalpy of formation (ΔfH⦵298) | -225.9 kJ/mol |
Hazards | |
Occupational safety and health (OHS/OSH): | |
Main hazards | carcinogen [2] |
Flash point | Non-flammable [2] |
Lethal dose or concentration (LD, LC): | |
LD50 (median dose) | 95 mg/kg (rat, oral) |
NIOSH (US health exposure limits): | |
PEL (Permissible) | none [2] |
REL (Recommended) | Ca TWA 0.001 mg/m3 [2] |
IDLH (Immediate danger) | N.D. [2] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Chlordecone, better known in the United States under the brand name Kepone, is an organochlorine compound and a colourless solid. It is an obsolete insecticide, now prohibited in the western world, but only after many thousands of tonnes had been produced and used. [3] Chlordecone is a known persistent organic pollutant (POP) that was banned globally by the Stockholm Convention on Persistent Organic Pollutants in 2009. [4]
Chlordecone is made by dimerizing hexachlorocyclopentadiene and hydrolyzing to a ketone. [5]
In the U.S., chlordecone, commercialized under the brand name "Kepone", was produced by Allied Signal Company and LifeSciences Product Company in Hopewell, Virginia. The improper handling and dumping of the substance (including the waste materials generated in its manufacturing process) into the nearby James River (U.S.) in the 1960s and 1970s drew national attention to its toxic effects on humans and wildlife. After two physicians, Dr. Yi-nan Chou and Dr. Robert S. Jackson of the Virginia Health Department, notified the Centers for Disease Control that employees of the company had been found to have toxic chemical poisoning, LifeSciences voluntarily closed its plant on July 4, 1975, and cleanup of the contamination began and a 100-mile section of the James River was closed to fishing while state health officials looked for other persons who might have been injured. [6] At least 29 people in the area were hospitalized as a result of their exposure to Kepone. [6]
The product is made in a Diels-Alder reaction shared with pesticides like chlordane and endosulfan. [3] Chlordecone was not federally regulated until after the Hopewell disaster, in which 29 factory workers were hospitalized with various ailments, including neurological. [7] Chlordecone is cited amongst a handful of other noxious substances as the driver for Gerald Ford's half-hearted approval in 1976 of the Toxic Substances Control Act, which "remains one of the most controversial regulatory bills ever passed". [8]
In 2009, chlordecone was included in the Stockholm Convention on Persistent Organic Pollutants, which bans its production and use worldwide. [4]
Chlordecone can accumulate in the liver and the distribution in the human body is regulated by binding of the pollutant or its metabolites to lipoproteins like LDL and HDL. [9] The LC50 (LC = lethal concentration) is 35 μg/ L for Etroplus maculatus , [10] 22–95 μg/kg for blue gill and trout. Chlordecone bioaccumulates in animals by factors up to a million-fold.
Workers with repeated exposure suffer severe convulsions resulting from degradation of the synaptic junctions. [3]
Chronic low level exposure appears to cause prostate cancer in men, [11] and "significant excesses of deaths were observed for stomach cancer in women and pancreatic cancer in women". [12]
Chlordecone has been found to act as an agonist of the GPER (GPR30), which interacts strongly with the estrogen sex hormone estradiol. [13]
The history of chlordecone incidents are reviewed in Who's Poisoning America?: Corporate Polluters and Their Victims in the Chemical Age (1982).
In July 1975, [14] Virginia Governor Mills Godwin Jr. shut down the James River to fishing for 100 miles, from Richmond to the Chesapeake Bay. [7] This ban remained in effect for 13 years, until efforts to clean up the river began to show results. [15]
Due to the pollution risks, many fishermen, marinas, seafood businesses, and restaurants, along with their employees along the river suffered economic losses. In 1981, a large group of these entities sued Allied Chemical in federal district court (Eastern District of Virginia), claiming special economic damages from Allied's negligent damage to the fish and wildlife. [16] In a case that sometimes appears in law school courses on Remedies, the court rejected the traditional "economic-loss rule", which requires physical impact causing personal injury or property damage to receive economic damages, and instead allowed a limited group of the plaintiffs—the fishing boat owners, the marinas, and the bait and tackle shops—to recover economic damages from Allied Chemical.
The French islands of Martinique and Guadeloupe are heavily contaminated with chlordecone, [17] following years of its massive and unrestricted use on banana plantations. [18] [19] Despite a 1990 ban on the substance in mainland France, the economically powerful banana planters lobbied intensively to obtain a waiver to keep using Kepone until 1993. They argued that no alternative pesticide was available, which has since been disputed. After the 1993 ban, the banana planters were discreetly granted derogations to use their remaining stocks, and a 2005 report prepared by the French National Assembly states that the chemical, under the name Curlone, most likely continued to be illegally imported and was used for many more years. [20] Since 2003, local authorities in the two islands have restricted cultivation of many food crops because the soil is badly contaminated by chlordecone. A 2018 large-scale study by the French public health agency, Santé publique France, shows that 95% of the inhabitants of Guadeloupe and 92% of those of Martinique are contaminated by the chemical. [21] Guadeloupe has one of the highest prostate cancer diagnosis rates in the world. [22]
Dichlorodiphenyltrichloroethane, commonly known as DDT, is a colorless, tasteless, and almost odorless crystalline chemical compound, an organochloride. Originally developed as an insecticide, it became infamous for its environmental impacts. DDT was first synthesized in 1874 by the Austrian chemist Othmar Zeidler. DDT's insecticidal action was discovered by the Swiss chemist Paul Hermann Müller in 1939. DDT was used in the second half of World War II to limit the spread of the insect-borne diseases malaria and typhus among civilians and troops. Müller was awarded the Nobel Prize in Physiology or Medicine in 1948 "for his discovery of the high efficiency of DDT as a contact poison against several arthropods".
Martinique is an island which is a single territorial collectivity of the French Republic. It is also part of the European Union as an Outermost Region within the Special territories of members of the European Economic Area, but is not part of the Schengen Area and the European Union Customs Union. As part of the French (Antilles) West Indies, Martinique is located in the Lesser Antilles of the West Indies in the eastern Caribbean Sea. It has a land area of 1,128 km2 (436 sq mi) and a population of 364,508 inhabitants as of January 2019. One of the Windward Islands, it is directly north of Saint Lucia, northwest of Barbados and south of Dominica. Martinique is an Outermost Region and a special territory of the European Union; the currency in use is the euro. Virtually the entire population speaks both French and Martinican Creole.
Polychlorinated biphenyls (PCBs) are highly carcinogenic chemical compounds, formerly used in industrial and consumer products, whose production was banned in the United States by the Toxic Substances Control Act in 1979 and internationally by the Stockholm Convention on Persistent Organic Pollutants in 2001. They are organic chlorine compounds with the formula C12H10−xClx; they were once widely used in the manufacture of carbonless copy paper, as heat transfer fluids, and as dielectric and coolant fluids for electrical equipment.
Formaldehyde is a naturally occurring organic compound with the formula CH2O and structure H−CHO. The pure compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde, hence it is stored as an aqueous solution (formalin), which is also used to store animal specimens. It is the simplest of the aldehydes. The common name of this substance comes from its similarity and relation to formic acid.
Bromomethane, commonly known as methyl bromide, is an organobromine compound with formula CH3Br. This colorless, odorless, nonflammable gas is produced both industrially and biologically. It has a tetrahedral shape and it is a recognized ozone-depleting chemical. It was used extensively as a pesticide until being phased out by most countries in the early 2000s.
Chlordane, or chlordan, is an organochlorine compound that was used as a pesticide. It is a white solid. In the United States, chlordane was used for termite-treatment of approximately 30 million homes until it was banned in 1988. Chlordane was banned 10 years earlier for food crops like corn and citrus, and on lawns and domestic gardens.
1,2-Dibromoethane, also known as ethylene dibromide (EDB), is an organobromine compound with the chemical formula C
2H
4Br
2. Although trace amounts occur naturally in the ocean, where it is formed probably by algae and kelp, it is mainly synthetic. It is a dense colorless liquid with a faint, sweet odor, detectable at 10 ppm, and is a widely used and sometimes-controversial fumigant. The combustion of 1,2-dibromoethane produces hydrogen bromide gas that is significantly corrosive.
Lindane, also known as gamma-hexachlorocyclohexane (γ-HCH), gammaxene, Gammallin and benzene hexachloride (BHC), is an organochlorine chemical and an isomer of hexachlorocyclohexane that has been used both as an agricultural insecticide and as a pharmaceutical treatment for lice and scabies.
Chlorpyrifos (CPS), also known as Chlorpyrifos ethyl, is an organophosphate pesticide that has been used on crops, animals, and buildings, and in other settings, to kill several pests, including insects and worms. It acts on the nervous systems of insects by inhibiting the acetylcholinesterase enzyme. Chlorpyrifos was patented in 1966 by Dow Chemical Company.
Endocrine disruptors, sometimes also referred to as hormonally active agents, endocrine disrupting chemicals, or endocrine disrupting compounds are chemicals that can interfere with endocrine systems. These disruptions can cause cancerous tumors, birth defects, and other developmental disorders. Found in many household and industrial products, endocrine disruptors "interfere with the synthesis, secretion, transport, binding, action, or elimination of natural hormones in the body that are responsible for development, behavior, fertility, and maintenance of homeostasis ."
Persistent organic pollutants (POPs) are organic compounds that are resistant to degradation through chemical, biological, and photolytic processes. They are toxic chemicals that adversely affect human health and the environment around the world. Because they can be transported by wind and water, most POPs generated in one country can and do affect people and wildlife far from where they are used and released.
Atrazine is a chlorinated herbicide of the triazine class. It is used to prevent pre-emergence broadleaf weeds in crops such as maize (corn), soybean and sugarcane and on turf, such as golf courses and residential lawns. Atrazine's primary manufacturer is Syngenta and it is one of the most widely used herbicides in the United States, Canadian, and Australian agriculture. Its use was banned in the European Union in 2004, when the EU found groundwater levels exceeding the limits set by regulators, and Syngenta could not show that this could be prevented nor that these levels were safe.
Dieldrin is an organochloride originally produced in 1948 by J. Hyman & Co, Denver, as an insecticide. Dieldrin is closely related to aldrin, which reacts further to form dieldrin. Aldrin is not toxic to insects; it is oxidized in the insect to form dieldrin which is the active compound. Both dieldrin and aldrin are named after the Diels-Alder reaction which is used to form aldrin from a mixture of norbornadiene and hexachlorocyclopentadiene.
Toxaphene was an insecticide used primarily for cotton in the southern United States during the late 1960s and the 1970s. Toxaphene is a mixture of over 670 different chemicals and is produced by reacting chlorine gas with camphene. It can be most commonly found as a yellow to amber waxy solid.
Aldrin is an organochlorine insecticide that was widely used until the 1990s, when it was banned in most countries. Aldrin is a member of the so-called "classic organochlorines" (COC) group of pesticides. COCs enjoyed a very sharp rise in popularity during and after The Second World War. Other noteworthy examples of COCs include DDT. After research showed that organochlorines can be highly toxic to the ecosystem through bioaccumulation, most were banned from use. It is a colourless solid. Before the ban, it was heavily used as a pesticide to treat seed and soil. Aldrin and related "cyclodiene" pesticides became notorious as persistent organic pollutants.
Endosulfan is an off-patent organochlorine insecticide and acaricide that is being phased out globally. It became a highly controversial agrichemical due to its acute toxicity, potential for bioaccumulation, and role as an endocrine disruptor. Because of its threats to human health and the environment, a global ban on the manufacture and use of endosulfan was negotiated under the Stockholm Convention in April 2011. The ban has taken effect in mid-2012, with certain uses exempted for five additional years. More than 80 countries, including the European Union, Australia, New Zealand, several West African nations, the United States, Brazil, and Canada had already banned it or announced phase-outs by the time the Stockholm Convention ban was agreed upon. It is still used extensively in India and China despite laws against its use. It is also used in a few other countries. It is produced by the Israeli firm Makhteshim Agan and several manufacturers in India and China. On 13.05.2011, the India Supreme Court ordered a ban on the production and sale of endosulfan in India, pending further notice.
Endrin is an organochloride with the chemical formula C12H8Cl6O that was first produced in 1950 by Shell and Velsicol Chemical Corporation. It was primarily used as an insecticide, as well as a rodenticide and piscicide. It is a colourless, odorless solid, although commercial samples are often off-white. Endrin was manufactured as an emulsifiable solution known commercially as Endrex. The compound became infamous as a persistent organic pollutant and for this reason it is banned in many countries.
Mirex is an organochloride that was commercialized as an insecticide and later banned because of its impact on the environment. This white crystalline odorless solid is a derivative of cyclopentadiene. It was popularized to control fire ants but by virtue of its chemical robustness and lipophilicity it was recognized as a bioaccumulative pollutant. The spread of the red imported fire ant was encouraged by the use of mirex, which also kills native ants that are highly competitive with the fire ants. The United States Environmental Protection Agency prohibited its use in 1976. It is prohibited by the Stockholm Convention on Persistent Organic Pollutants.
Methoxychlor is a synthetic organochloride insecticide, now obsolete.
1,3-Dichloropropene, sold under diverse trade names, is an organochlorine compound. It is colorless liquid with a sweet smell. It dissolves in water and evaporates easily. It is used mainly in farming as a pesticide, specifically as a preplant fumigant and nematicide. It is widely used in the US and other countries, but is banned in 34 countries, including the European Union.