Description
Etrimfos is a colorless liquid, mp ?3.35 ?C, vp 6.5 mPa
(20 ?C). Solubility in water is 40 mg/L (23–24 ?C). It is
miscible with most organic solvents. Log Kow > 3.3. Neat
etrimfos is unstable and degrades ca. 40% in 28 d at
50 ?C, but the dilute solutions in nonpolar solvents and its
formulations are stable (about 5% loss in 1 y at ca. 20 ?C).
It is hydrolyzed in aqueous media; DT
50 (25 ?C) at pH 3, 6,
and 9 are 0.4, 16, and 14 d, respectively.
Uses
Satisfar is a pesticide sprayed on plants and vegetables as insecticide to fend off pests.
Uses
Etrimfos is used to control chewing insects in top fruit, vines,
olives and a number of other crops. It is also used to control stem borers in
rice and insect and acarid pests of stored products.
Uses
Agricultural insecticide.
Definition
ChEBI: Etrimfos is an organic thiophosphate.
Metabolic pathway
Etrimfos is principally degraded in soil and plants via dearylation of
etrimfos itself or by hydrolysis of etrimfos oxon to the pyrimidinol
(6-ethoxy-4-hydroxy-2-ethylpyrimidine), further metabolism of which
involves de-ethylation to a dihydroxypyrimidine (2-ethyl-4,6-dihydroxypyrimidine).
In mammals both hydrolysis and demethylation to desmethyl
etrimfos are involved in detoxification. Additionally, the ethyl and
ethoxy groups of the pyrimidinol hydrolysis product may be hydroxylated
and conjugated. Etrimfos oxon is metabolically highly unstable and
is often not detected.
Degradation
Etrimfos is unstable when pure but dilute solutions in non-polar solvents
and formulations are stable. Half-lives in water at pH 3,6 and 9 were 0.4,
16 and 14 days, respectively. Etrimfos is stable to light (PM).
Toxicity evaluation
The acute oral LD
50 for rats is 1,600–1,800 mg/kg.
Inhalation LC50 (1 h) for rats is >200 mg/L air. NOEL
(2 yr) for rats is 6 mg/kg diet (0.3 mg/kg/d). ADI is
3 μg/kg b.w. The principal degradation pathway in
mammals, plants, and soils is pyrimidinyl ester bond
cleavage: the major metabolites are 6-ethoxy-4-hydroxy-
2-ethylpyrimidine and its further transformed products.
Degradation in mammals involves demethylation to
desmethyl etrimfos. The DT
50 in soils at pH 6.8 was
3–10 d.
