Diazinon

• O, O -diethyl- O-( 2-isopropyl- 6-methyl- pyrimidin-4- yl) phosphorothioate,
• Dimpylat ( INN)
• Basudin

Colorless to yellowish liquid with a faint odor ester type

Liquid

1.12 g · cm -3

<25 ° C

18 MPa (20 ° C)

Very poor in water ( 40-47 mg · l-1 at 20 ° C) ( slow decomposition)

1.4922 (20 ° C)

Attention

0.1 mg · m-3

• 214 mg · kg -1 ( TDLo, man, oral)
• 66 mg · kg -1 ( LD50, rat, oral)
• 17 mg · kg -1 ( LD50, mouse, oral)

Template: Infobox chemical / molecular formula search available

Diazinon is a thiophosphoric acid ester, which is used as a non- systemic insecticide and acaricide. Diazinon was developed in 1952 by the Swiss company Geigy AG, which then later became Novartis, and Syngenta.

History

Diazinon was provided by Geigy as the successor product for DDT. In 1953, the DDT manufacturing factory near Basel Swiss was temporarily in 1955 then finally stopped, because the capacity for diazinon were needed. In the manufacture of diazinon compared to DDT were the fire and explosion risk is higher and the odor nuisance and toxic effects for the workers greater. Until the late 1970s, commercial diazinon also contained toxic impurities and decomposition products. Later they were removed by separation processes or preventing their formation by the addition of stabilizers.

Use

Pest control

Diazinon is used against foliar and soil insects, but does not species-specific, but attacks all insects. The main applications are the control of cockroaches, silverfish, ants and fleas in residential areas that are not used for food storage or preparation. The toxic effect is due to inhibition of acetylcholinesterase.

Accordance with European legislation (Directive 98/8/EC concerning the placing of biocidal products ) and by decision of 8 February 2010 is a decision before the active ingredient diazinon not in the appropriate list ( Annex I / IA of Directive 98/ 8 / EC ) for biocidal products (product type 18 record ). The release of biocidal products containing the active ingredient diazinon is therefore in the EU ( Switzerland has adopted this provision ) is no longer allowed for insecticides from 1 March 2011.

Plant protection

Diazinon is no longer permitted as an active ingredient in plant protection products as a result of a decision by the EU Kommissiom on 6 June 2007. In Switzerland, diazinon has been deleted from the Annex of approved active substances on May 15, 2011. In the U.S., diazinon is still allowed, but one of the most restricted pesticides. The use has fallen sharply in the last 20 years.

Toxicology

Diazinon has a relatively high toxicity to vertebrate species. It is absorbed through the skin. Symptoms of poisoning are similar to those of other inhibitors of cholinesterases: it occurs among other colic, nausea, diarrhea and vomiting, dizziness, headache, blurred vision ( accommodation disorder ), contracted and non-reactive pupils ( miosis ), bradycardia, hypotension, to convulsions and apnea.

The LD50 for rats with oral 66 mg / kg; for mice 17 mg / kg of the known lowest toxic dose ( TDLo ) for humans is oral administration at 214 mg / kg. It has the water hazard class 3 (highly hazardous).