Azamethiphos is an
organothiophosphate insecticide. It is a
veterinary drug used in
Atlantic salmon fish farm
upright=1.3, mariculture.html" ;"title="Salmon farming in the sea (mariculture">Salmon farming in the sea (mariculture) at Loch Ainort, Isle of Skye, Scotland
Fish farming or pisciculture involves commercial animal husbandry, breeding of fish, ...
ing to control parasites. It is also used as an insecticide in biocidal products in Europe.
Mode of action
Organophosphorus insecticides, such as Azamethiphos, inhibit the action of the enzyme
acetylcholinesterase
Acetylcholinesterase (HGNC symbol ACHE; EC 3.1.1.7; systematic name acetylcholine acetylhydrolase), also known as AChE, AChase or acetylhydrolase, is the primary cholinesterase in the body. It is an enzyme that catalyzes the breakdown of acety ...
. The acetylcholine, therefore, remains intact allowing the electrical signal to proceed without interruption. This phenomenon leads to overexcitation of the organism and eventually to the death of the insect.
[Armosa factsheet on Azamethiphos, February 2022]
Azamethiphos penetrates through the cuticle or through the cuticle opening of the insect, and also acts by ingestion and absorption through the digestive system.
Registration
In Europe, Azamethiphos is an active substance according to the Biocide Regulation 528/2012, to be used as insecticide.
It is used in several biocidal products in Europe, as insecticide mainly for professional users. It is commonly used against flies in animal housing.
Stability
Azamethiphos is sensitive to hydrolysis, especially at low pH.
Toxicity
Azamethiphos is of moderate acute oral toxicity (LD50 values ranging from 834 mg kg-1 in the rat to 1764 mg kg-1 in the hamster). Acute dermal toxicity is very low (LD50 values of >2020 and >6000 mg kg-1 are reported in the rabbit and an LD50 of >2150 mg kg-1 is reported in the rat).
Azamethiphos is irritant to eyes and skin.
Environmental toxicity
Azamethiphos is very toxic for the environment, with a LC50 on ''Daphnia magna'' of 0.33 µg/L.
References
Organothiophosphate esters
Insecticides
Veterinary drugs
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