Chlordane

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Structural formula
Structural formula chlordane
Simplified structural formula without stereochemistry
General
Surname Chlordane
other names
  • 1,2,4,5,6,7,8,8-octachlor-3a, 4,7,7a-tetrahydro-4,7-methano-indane (representative example in a complex mixture of substances)
  • Octachlor
Molecular formula C 10 H 6 Cl 8
Brief description

brown solid, technically mostly viscous liquid

External identifiers / databases
CAS number 57-74-9
EC number 200-349-0
ECHA InfoCard 100,000,317
PubChem 5993
ChemSpider 5772
Wikidata Q417134
properties
Molar mass 409.8 g mol −1
Physical state

firmly

density

1.59–1.63 g cm −3 (25 ° C)

Melting point
  • 106–107 ° C ( cis modification)
  • 104–105 ° C ( trans modification)
boiling point

175 ° C (1.3 h Pa )

solubility

almost insoluble in water (0.1 mg l −1 )

safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary
08 - Dangerous to health 07 - Warning 09 - Dangerous for the environment

Caution

H and P phrases H: 351-312-302-410
P: 210-260-280-301 + 310-311
MAK

DFG / Switzerland: 0.5 mg m −3 (measured as inhalable dust )

As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Chlordane is an insecticide from the group of chlorinated hydrocarbons that acts as a contact poison .

The plant protection product was launched on the market in 1947 as a non-systemic (= not absorbed by the plant) contact and feeding insecticide and is considered the first cyclodiene pesticide in agriculture .

Extraction and presentation

Technical chlordane is a reaction Diels-Alder made: This is cyclopentadiene to hexachlorocyclopentadiene condensed. The resulting chlordene is chlorinated so that cis - and trans -chlorodane are formed from it. Substitution with chlorine can produce heptachlor from chlordane. Further additions of chlorine also produce cis - and trans -nonachlor. Technically produced chlordane is a mixture of at least 50, more recent studies have shown at least 147 components, the composition of which varies depending on the manufacturing process. Initially it contained 43–75% cis - and trans -chloride and smaller amounts of heptachlor, cis - and trans -nonachlor and chlordenene. After 1970, improved manufacturing options made it possible to manufacture a purer product with at least 95% cis and trans chlorordane. Before 1951, the mixture also contained large proportions of hexachlorocyclopentadiene.

Synthesis of cis - (top) and trans -chlorordane (bottom)

use

Chlordane was mainly used for agricultural purposes, mainly for soil and seed treatment, in grain, potato and vegetable cultivation. It was also used as a wood preservative against fire ants and termites . It was mainly used in the United States of America , after Toxaphen it was the most important insecticide belonging to the group of chlorinated hydrocarbons between 1976 and 1977.

composition

Chlordane consists of a complex mixture of at least 147 individual components, some of which are optically active . For the most part, the mixture is composed of trans -chloride, cis -chlorordane and also of achiral trans -nonachlor and heptachlor .

  • trans -Chlordane (also known as "γ-Chlordane")

  • cis -chlorordane (also known as "α-chlorordane")

  • trans -nonachlor

  • (+) - heptachlor

Environmental behavior

Because of its persistence , chlordane remains relatively stable in the natural environment and can be spread over great distances. The persistence of chlorodane compounds increases with the number of their chlorine atoms. Since chlordane and related compounds have fat-soluble properties, it is stored in organisms (= so-called bioaccumulation ) and enriched in the food chain (= so-called biomagnification ). In mammals, chlordane is mainly stored in the nervous system and the liver.

toxicity

Chlordane has a medium acute toxicity . Acute poisoning via the food chain can damage the liver, kidneys, heart, lungs and intestines; inhaling dust can cause inflammation of the airways and lungs. Oxychlordane (a major metabolite of cis and trans chlorordane) and nonachlor are more toxic than cis and trans chlorordane. In animal experiments, chlordane caused liver cancer in mice - presumably via non-genotoxic mechanisms . Therefore, it is classified by the International Agency for Cancer Research as possibly carcinogenic for humans in group 2B and in the MAK list under IIIB. Chlordane is moderately to highly toxic to fish when exposed to water. At present (2008), however, there are no studies on the toxicity of exposure through fish feed. Laying hens show a reduced laying performance when given high doses of chlordane. In the context of long-term studies in dogs, a permissible NOAEL of 0.075 mg / kg body weight per day (3 mg / kg food) with regard to liver toxicity was determined. No further studies are currently (2008) available for other farm or pet species.

With the exception of fish products, chlorine enrichment is not often found in feed. The concentrations determined are in the lower µg / kg range and thus far below the values ​​that show adverse effects on dogs. The metabolism and excretion of chlordane and related compounds differ greatly between species. In animal tissues and products, residues of chlorine compounds can be detected as oxychlordane and trans -nonachlor. People currently ingest an average of a few ng of chlordane per kg of body weight per day. This is far below the tolerable daily intake of 500 ng / kg body weight, which was provisionally set by the World Health Organization in 1995 . It should be noted that the concentrations of chlordane in breast milk are usually 10 times higher than in cow's milk .

Analytical evidence

The chemical-analytical detection in environmental samples, food and animal feed is carried out after suitable sample preparation to separate the matrix and gas chromatographic separation of minor components by high-resolution mass spectrometry techniques such as flight mass spectrometry (Time-Of-Flight mass spectrometry).

Legal situation

Because of its toxicity and persistence, the production, sale and use of chlordane has been banned in Germany since 1971 , in the European Union since 1981 and in the USA since 1988 ; many states later followed suit. Today the use of chlordane is banned almost worldwide. Chlordane is covered by the Stockholm Convention of 22 May 2001 on persistent organic pollutants ( POP = persistent organic pollutants of) and the Convention Economic Commission for Europe of the United Nations (UNECE) on long-range transboundary air pollution with POPs ( CLRTAP -POP). That "dirty dozen" includes chlordane. On May 17, 2004, following ratification by the 50th Accession State, the Convention became globally valid.

Trade names

Chlordan was sold under the trade names Aspon, Belt, CD 68, Chlordan, Chlorindan, Chlor-Kil, Chlorotox, Corodane, Cortilan-neu, Dowchlor, Gold Crest C-100, HCS 3260, Intox, Kilex, Kypchlor, M-140, Niran, Octachlor, Oktaterr, Ortho-Klor, Penticklor, Prentox, Starchlor, Sydane, Synklor, Tat Chlor 4, Termex, Topichlor, Toxichlor, Unexan-Koeder and Velsicol 1068.

Individual evidence

  1. ↑ a b c d e f g h Entry on chlordane in the GESTIS substance database of the IFA , accessed on February 22, 2017(JavaScript required) .
  2. ↑ Entry on Chlordane, pure in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
  3. ↑ Data sheet Chlordane (mixture of isomers) from Sigma-Aldrich , accessed on March 17, 2011 ( PDF ).
  4. ↑ Swiss Accident Insurance Fund (Suva): Limit values ​​- current MAK and BAT values (search for 57-74-9 or chlordane ), accessed on November 2, 2015.
  5. ^ Roland Eisler: Eisler's Encyclopedia of Environmentally Hazardous Priority Chemicals . Elsevier Ltd 2007; ISBN 978-1857763768 ; P. 111.
  6. ^ Roland Eisler: Eisler's Encyclopedia of Environmentally Hazardous Priority Chemicals . Elsevier Ltd 2007; ISBN 978-1857763768 ; P. 112.
  7. ↑ a b Liu, W., Ye, J. and Jin, M. (2009): Enantioselective phytoeffects of chiral pesticides. In: J Agric Food Chem . 57 (6); 2087-2095; PMID 19292458 ; doi : 10.1021 / jf900079y
  8. ↑ a b Mark A. Dearth, Ronald A. Hites (1991): Complete analysis of technical chlordane using negative ionization mass spectrometry , in: Environmental Science & Technology , 25 (2), pp. 245-254; doi : 10.1021 / es00014a005 .
  9. ↑ Rosenberg MM, Tanaka T., Adler, HE (1950): Toxicity of chlordane to laying pullets , in: American Journal of Veterinary Research, 11, pp. 236-239; PMID 15410985 .
  10. ↑ Eric J. Reiner, Adrienne R. Boden, Tony Chen, Karen A. MacPherson and Alina M. Muscalu: Advances in the Analysis of Persistent Halogenated Organic Compounds . In: LC GC Europe . 23: 60-70 (2010).
  11. ↑ General Directorate Health and Food Safety of the European Commission: Entry on Chlordane in the EU pesticide database; Entry in the national registers of plant protection products in Switzerland , Austria and Germany ; accessed on March 26, 2016.
  12. ↑ Opinion of the Scientific Panel on Contaminants in the Food Chain at the request of the European Commission on chlordane as an undesirable substance in feed, in: The EFSA Journal (2007) 582, pp. 1–53; doi : 10.2903 / j.efsa.2007.582 .

literature