Metribuzin

Metribuzin

嗪草酮

4-amino-6-tert-butyl-4,5-dihydro-3-methylthio-1,2,4-triazin-5-one
or
4-amino-6-tert-butyl-3-methylthio-1,2,4-triazin-5(4H)-one

4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one

21087-64-9

C₈H₁₄N₄OS

Herbicides > Triazinone herbicides

Herbicide

Rimsulfuron+metribuzin
Metribuzin+Metolachlor+2,4-D-ethylhexyl
Metribuzin+Clethodim+Rimsulfuron
Metolachlor+metribuzin
Chlorimuron-ethyl+metribuzin
chlorimuron+metribuzin+flumioxazin
Acetochlor+Metribuzin+2,4-D-ethylhexyl
Liquid suspension, water dispersible granules, dry flowable. 
Premix Parters: atrazine;

Molecular weight:214.3; Physical form:White crystals, with a weak characteristic odour. Density:1.28 (20 °C); Melting point:126.2 °C; Vapour pressure:0.058 mPa (20 °C); Henry constant:1 ×10-5 Pa m3 mol-1 (20 °C, calc.); Partition coefficient(n-octanol and water):logP = 1.6 ( pH 5.6, 20 °C); Solubility:In water 1.05 g/l (20 °C). In dimethylformamide 1780, cyclohexanone 1000, chloroform 850, acetone 820, methanol 450, dichloromethane 340, benzene 220, n-butanol 150, ethanol 190, toluene 87, xylene 90, isopropanol 77, hexane 1.0 (all in g/l, 20 °; Stability:Relatively stable to u.v. irradiation. At 20 °C, stable to dilute acids and alkalis; DT50 (37 °C) 6.7 h ( pH 1.2); DT50 (70 °C) 569 h ( pH 4), 47 d;

Oral:Acute oral LD₅₀ for rats c. 2000, mice c. 700, guinea pigs c. 250, cats >500 mg/ kg. Percutaneous:Acute percutaneous LD₅₀ for rats >20 000 mg/kg. Not irritating to skin and eyes (rabbits). Inhalation: LC₅₀ (4 h) for rats >0.65 mg/l air (dust). Phytotoxicity:Phytotoxic to many crops, including crucifers, cucurbits, lettuce, onions, sugar beet, sunflowers, flax, strawberries, sweet potatoes, and tobacco.

Ecotoxicology: 
Algae:rC₅₀ for Scenedesmus subspicatus 0.021 /l.Bees:Not toxic to bees; 50 35 mg/bee.Birds:Acute oral 50 for bobwhite quail 168, mallard ducks 460-680 /kg. Dietary 50 (5 d) for bobwhite quail and mallard ducks >4000 / diet.Daphnia:50 (48 h) 4.5-35 /l.Fish:50 (96 h) for bluegill sunfish 80, rainbow trout 76, goldfish >10, catfish >10 .Worms:50 for Eisenia foetida 331.8 / dry soil.

Environmental fate: 
Animals:In mammals, following oral administration, 98% elimination occurs within 96 hours, about equally in the urine and the faeces.Soil:Metribuzin is rapidly degraded in soil; microbial breakdown is the major mechanism of loss. Degradation involves deamination, followed by further degradation to water-soluble conjugates. Photodecomposition on soil surfaces and in aqueous solution is an imPlant:In plants, metribuzin undergoes oxidative deamination and further degradation to water-soluble conjugates.

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