Chlorothiamide

Structural formula
General
Surname	Chlorothiamide
other names	2,6-dichlorothiobenzamide
Molecular formula	C 7 H 5 Cl 2 NS
Brief description	yellow solid
External identifiers / databases
CAS number 1918-13-4 EC number 217-637-7 ECHA InfoCard 100.016.035 PubChem 2734819 Wikidata Q411727
properties
Molar mass	206.09 g mol −1
Physical state	firmly
Melting point	151–152 ° C (decomposition)
solubility	poor in water (0.95 g l −1 at 21 ° C)
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary Caution H and P phrases H: 302 P: 270-301 + 312-330-501
Toxicological data	757 mg kg −1 ( LD 50 ,  rat ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Chlorthiamid is a herbicide from the group of thiocarboxamides ( thionamides ). Under normal conditions it is a white, solid substance and is not flammable.

history

Chlorothiamide was manufactured by Shell Chemical Company and sold under the trade name Prefix . In Germany it was used to control weeds in orchards and viticulture as well as against dock on cattle pastures. In the forest it was used against bracken . Chlorthiamide came on the market as granules with an active ingredient content of 7.5%, or as a combination preparation with the active ingredient Dalapon .

In the Federal Republic of Germany, a waiting period of 21 days had to be observed after use on grassland; after use under pome fruit and currants, the deadline specified for the respective product in the approval. Chlorothiamide residues in all vegetable foods were not allowed to exceed 0.1 mg / kg (status 1982).

Admission

In the EU countries such as Germany and Austria as well as Switzerland is not a pesticide approved more with this drug.

Chemical properties

When heated or when burned, chlorothiamide decomposes, producing corrosive, toxic fumes ( hydrogen chloride , sulfur oxides , nitrogen oxides ). In the soil, chlorothiamide is broken down into dichlobenil, among other things .

Toxicology and Ecotoxicology

The acute oral LD ₅₀ for the rat is given as 750 mg / kg body weight, the dermal LD ₅₀ as over 1000 mg / kg.

Chlorthiamide was classified as not dangerous to bees and not poisonous to fish. A mean LC ₅₀ of 41 mg / l (24 hours) and 33 mg / l (48 hours) was found for several fish species .

The after-effect time in the soil was determined to be 5 to 7 months.

literature

• Griffiths, MH; Moss, YES; Rose, YES; Hathway, DE "The comparative metabolism of 2,6-dichlorothiobenzamide (prefix) and 2,6-dichlorobenzonitrile in the dog and rat", in: Biochem J. , 1966 , 98 , pp. 770-781; PMC 1264918 (free full text, PDF).

Web links

• International Chemical Safety Card (ICSC) for CHLORTHIAMID at the National Institute for Occupational Safety and Health (NIOSH).

Individual evidence

1. ↑ ^{a b} data sheet chlorothiamide from AlfaAesar, accessed on April 2, 2010 ( PDF )(JavaScript required) .
2. ↑ ^{a b c} Entry on chlorothiamide in the GESTIS substance database of the IFA , accessed on February 21, 2017(JavaScript required) .
3. ↑ Entry on chlorothiamide in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers and / or distributors can expand the harmonized classification and labeling .
4. ↑ Entry on chlorothiamide in the ChemIDplus database of the United States National Library of Medicine (NLM) .
5. ↑ ^{a b} Werner Perkow: "Active substances of plant protection and pest control agents", 2nd edition, Paul Parey publishing house
6. ↑ General Directorate Health and Food Safety of the European Commission: Entry on chlorthiamide in the EU pesticide database; Entry in the national registers of plant protection products in Switzerland , Austria and Germany ; Retrieved March 3, 2016.
7. ↑ Beynon, KI; Wright, AN: Persistence, Penetration, and Breakdown of Chlorthiamid and Dichlobenil Herbicides in Field Soils of Different Types , in: J. Sc. Fd. Agric. , 1968 , 19 , pp. 718-722.