Kepone

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Kepone
Chlordecone.png
Chlordecone Kepone 3D.png
Names
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
CAS number143-50-0 YesY
ChEBICHEBI:16548 N
ChEMBLChEMBL462576 YesY
ChemSpider293 YesY
EC number205-601-3
Jmol-3D imagesImage
KEGGC01792 YesY
PubChem299
UNIIRG5XJ88UDF N
Properties
C10Cl10O
Molar mass490.64 g·mol−1
Appearancetan to white crystalline solid
Odorodorless
Density1.6 g/cm3
Melting point349 °C (660 °F; 622 K) (decomposes)
0.27 g/100 mL
Solubilitysoluble in acetone, ketone, acetic acid
slightly soluble in benzene, hexane
log P5.41
Vapor pressure3.10−7 kPa
Thermochemistry
764 J/K mol
-225.9 kJ/mol
Hazards
Flash pointNon-flammable
95 mg/kg (rat, oral)
US health exposure limits (NIOSH):
none[2]
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N verify (what isYesY/N?)
Infobox references
 
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This article is about the pesticide. For the indie rock band, see Kepone (band).
Kepone
Chlordecone.png
Chlordecone Kepone 3D.png
Names
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
CAS number143-50-0 YesY
ChEBICHEBI:16548 N
ChEMBLChEMBL462576 YesY
ChemSpider293 YesY
EC number205-601-3
Jmol-3D imagesImage
KEGGC01792 YesY
PubChem299
UNIIRG5XJ88UDF N
Properties
C10Cl10O
Molar mass490.64 g·mol−1
Appearancetan to white crystalline solid
Odorodorless
Density1.6 g/cm3
Melting point349 °C (660 °F; 622 K) (decomposes)
0.27 g/100 mL
Solubilitysoluble in acetone, ketone, acetic acid
slightly soluble in benzene, hexane
log P5.41
Vapor pressure3.10−7 kPa
Thermochemistry
764 J/K mol
-225.9 kJ/mol
Hazards
Flash pointNon-flammable
95 mg/kg (rat, oral)
US health exposure limits (NIOSH):
none[2]
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N verify (what isYesY/N?)
Infobox references

Kepone, also known as chlordecone, is an organochlorine compound. It is a colourless solid. This compound is a controversial insecticide related to Mirex and DDT. Its use was so disastrous that it is now prohibited in the western world, but only after many millions of kilograms had been produced.[3] Kepone is a known persistent organic pollutants (POP), classified among the "dirty dozen" and banned globally by the Stockholm Convention on Persistent Organic Pollutants as of 2011.

Toxicology[edit]

The LC50 (LC = lethal concentration) is 0.022–0.095 mg/kg for blue gill and trout. Kepone bioaccumulates in animals by a factors up to a million-fold. Workers with repeated exposure suffer severe convulsions resulting from degradation of the synaptic junctions.[3]

History[edit]

In the US, kepone was produced by Allied Signal Company and LifeSciences Product Company in Hopewell, Virginia. The improper handling and dumping of the substance into the nearby James River (U.S.) in the 1960s and 1970s drew national attention to its toxic effects on wildlife. The product is similar to DDT and is a degradation product of Mirex.[3] The history of Kepone incidents are reviewed in Who's Poisoning America?: Corporate Polluters and Their Victims in the Chemical Age (1982). In 2009, Kepone was included in the Stockholm Convention on persistent organic pollutants, which bans its production and use worldwide.[4]

Case studies[edit]

James River estuary[edit]

Due to the pollution risks, many businesses and restaurants along the river suffered economic losses. In 1975 Governor Mills Godwin Jr. shut down the James River to fishing for 100 miles, from Richmond to the Chesapeake Bay. This ban remained in effect for 13 years, until efforts to clean up the river began to get results.[5]

French Antilles[edit]

The French island of Martinique is heavily contaminated with kepone,[6] following years of its unrestricted use on banana plantations. Despite a 1990 ban of the substance by France, the economically powerful planter community lobbied intensively to gain the power to continue using kepone until 1993. They had argued that no alternative pesticide was available, which has since been disputed. Similarly, the nearby island of Guadeloupe is also contaminated, but to a lesser extent. Since 2003, the local authorities restricted cultivation of crops because the soil has been seriously contaminated by kepone. Guadeloupe has one of the highest prostate cancer rates in the world.[7]

In popular culture[edit]

Synthesis[edit]

Kepone is made by dimerizing hexachlorocyclopentadiene and hydrolyzing to a ketone.[8]

References[edit]

  1. ^ IUPAC Agrochemical information (http://sitem.herts.ac.uk/aeru/iupac/1293.htm)
  2. ^ NIOSH Pocket Guide to Chemical Hazards 0365
  3. ^ a b c Robert L. Metcalf "Insect Control" in Ullmann's Encyclopedia of Industrial Chemistry Wiley-VCH, Wienheim, 2002. doi:10.1002/14356007.a14_263
  4. ^ Stockholm Convention. Listing of POPs in the Stockholm Convention: Annex A (Elimination). 2011; Available from: http://chm.pops.int/Convention/The%20POPs/tabid/673/language/fr-CH/Default.aspx.
  5. ^ Jack Cooksey, "What's in the Water?", Richmond Magazine, June 2007, accessed 13 June 2012
  6. ^ Durimel, A., et al., pH dependence of chlordecone adsorption on activated carbons and role of adsorbent physico-chemical properties. Chemical Engineering Journal, 2013. 229: p. 239-349.
  7. ^ European Journal, Deutsche Welle, 26 May 2010.[1]
  8. ^ Survey of Industrial Chemistry by Philip J. Chenier (2002) page 484.

External links[edit]