Common name: Quinalphos
IUPAC name: O,O-diethyl O-quinoxalin-2-yl phosphorothioate
Chemical Abstracts name:O,O-diethyl O-2-quinoxalinyl phosphorothioate
CAS RN: [13593-03-8]
PHYSICAL CHEMISTRY
Mol. wt.: 298.3
Form:Colourless crystals.
M.p.: 31-32 ºC
B.p.: 142 ºC/0.0003 mmHg (decomp.)
V.p.: 0.346 mPa (20 ºC)
Kow logP = 4.44 (23 ºC, 10-100 ppm level)
S.g./density: 1.235 (20 ºC)
Solubility In water 17.8 mg/l (22-23 ºC). In hexane 250 g/l (23 ºC). Readily soluble in toluene, xylene, diethyl ether, ethyl acetate, acetone, acetonitrile, methanol, ethanol. Slightly soluble in petroleum ether (23 °C).
Stability A.i. stable 14 d at room temperature; liquid tech. grade less stable but stable under ambient storage conditions, when diluted in non-polar organic solvents and in the presence of stabilising agents. Formulations are stable (shelf life at ave. ann. temp. ≤25℃ c. 2 y). Susceptible to hydrolysis; DT50 (25 ºC, 17 ppm and 2.5 ppm) 23 d (pH 3), 39 d (pH 6), 26 d (pH 9).
TOXICOLOGY
Oral Acute oral LD50 for male rats 71 mg/kg.
Skin and eye Acute percutaneous LD50 for male rats 1750 mg/kg. Non-irritating to skin and eyes (rabbits)
Inhalation LC50 (4 h) for rats 0.45 mg/l air.
NOEL (2 y) (based on cholinesterase inhibition) for rats 3 mg/kg diet.
ADI (JMPR) No teratogenic effects (rats and rabbits); no mutagenic potential. Cholinesterase inhibitor in rats, mice, and dogs.
Toxicity class WHO (a.i.) II
EPA (formulation) II
EC hazard T; R25| Xn; R21
ECOTOXICOLOGY
Birds Acute oral LD50 (14 d) for Japanese quail 4.3, mallard ducks 37 mg/kg. Dietary LC50 (8 d) for quail 66, mallard ducks 220 mg/kg.
Fish LC50 (96 h) for carp 3.63, rainbow trout 0.005 mg/l.
Daphnia LC50 (48 h) 0.66 mg/l.
Bees Very toxic to bees. LD50 (oral) 0.07 mg/bee; (topical) 0.17 mg/bee.
Worms LC50 (7 d) 188 mg/kg soil; (14 d) 118.4 mg/kg soil.
