Etridiazole

Etridiazole

土菌灵

ethyl 3-trichloromethyl-1,2,4-thiadiazol-5-yl ether

5-ethoxy-3-(trichloromethyl)-1,2,4-thiadiazole

2593-15-9

C₅H₅Cl₃N₂OS

Fungicides > Thiadiazole fungicides

Fungicide

Molecular weight:247.5; Physical form:Pale yellow liquid, with a persistent odour; ( tech. is a reddish-brown liquid). Density:1.503 (25 °C); Composition:Tech. grade is >96% pure. Melting point:19.9 °C; Flash point:66 °C; Vapour pressure:1430 mPa (25 °C); Henry constant:3.03 Pa m3 mol-1 ( calc.); Partition coefficient(n-octanol and water):logP = 3.37; pKa:2.77, v. weak base; Solubility:In water 117 mg/l (25 °C). Miscible with ethanol, methanol, aromatic hydrocarbons, acetonitrile, hexane, xylene.; Stability:Stable for 14 d at 55 °C. After continuous exposure to sunlight for 7 d at 20 °C, 5.5-7.5% decomposition. Hydrolysis DT50 12 d ( pH 6, 45 °C), 103 d ( pH 6, 25 °C).

Oral:Acute oral LD₅₀ for rats 1100 mg/ kg. Percutaneous:Acute percutaneous LD₅₀ for rabbits >5000 mg/kg. Not irritating to skin; mild eye irritant (rabbits). Inhalation: LC₅₀ (4 h) for rats >5.7 mg/l.

Ecotoxicology: 
Algae: EC₅₀ (5 d) for Selenastrum 0.072, Anabaena 0.29, Navicula 0.43, Skeletonema 0.38 mg/l.Birds:Acute oral LD₅₀ for bobwhite quail 560 mg/kg. Dietary LC₅₀ (8 d) for bobwhite quail >5000 ppm, for mallard ducks 1650 mg/ kg.Daphnia: LC₅₀ (48 h) 4.9 mg/l.Fish: LC₅₀ (216 h) for rainbow trout 1.21, bluegill sunfish 3.27 mg/l.Other aquatic spp.: LC₅₀ (96 h) for mysid shrimp (Mysidopsis bahia) 2.5, oyster (Crassostrea) 3.0 mg/l. 

Environmental fate: 
Animals:In mammals, following oral administration, the water-soluble metabolite 3-carboxy-5-ethoxy-1,2,4-thiadiazole has been found. In rat urine, this compound was found as a major metabolite and N-acetyl-S-(5-ethoxy-1,2,4-thiadiazol-3-yl-methySoil:Soil 50 in silt loam in laboratory at 25 °C (aerobic) 9.5 d, (anaerobic) 3 d. Field dissipation, in sandy clay loam, DT₅₀ 1 w. Soil adsorption K 5.31 (sandy soil), 1.41 (silt loam).Plant:The trichloromethyl group is readily converted to the acid or alcohol, and the ethoxy group is hydroxylated to form a hydroxyethyl derivative. Some plants convert etridiazole more extensively to form natural products.

Signal Word:CAUTION; Hazard Class:III(Slightly hazardous)