Chlorthal-dimethyl

Chlorthal-dimethyl

氯酞酸甲酯

dimethyl tetrachloroterephthalate

dimethyl 2,3,5,6-tetrachloro-1,4-benzenedicarboxylate

1861-32-1

C₁₀H₆Cl₄O₄

Herbicides > Aromatic acid herbicides

Herbicide

Molecular weight:332.0; Physical form:Colourless crystals,slight aromatic odor. Melting point:156 °C; Vapour pressure:0.21 mPa (25 °C, gas saturation method); Henry constant:1.39×10-1 Pa m3 mol-1 (calc.); Partition coefficient(n-octanol and water):logP = 4.28 (25 °C); Solubility:In water c. 0.5 mg/l (25 °C). In benzene 250, toluene 170, xylene 140, dioxane 120, acetone 100, carbon tetrachloride 70 (all in g/kg, 25 °C).; Stability:Stable to heat and u.v. light. Decomposes at c. 360-370 °C.

Oral:Acute oral LD₅₀ for rats >12.5 g/kg, dogs >10.0 g/kg. Percutaneous:Acute percutaneous LD₅₀ for albino rabbits >2 g/kg. Mild dermal irritant; slight eye irritant (rabbits). Inhalation:LC₅₀ (4 h) for rats >4.5 mg/l. Phytotoxicity:Phytotoxic to beet, spinach, flax, and trefoil. ADI:0.05 mg/kg.

Ecotoxicology: Bees:Slightly toxic to bees.Birds:LD₅₀ for bobwhite quail >2250 mg/kg. Dietary LC₅₀ (5 d) for bobwhite quail and mallard ducks >5620 ppm.Daphnia:LC₅₀ (48 h) >4.6 mg/l.Fish:Mildly toxic to fish. LC₅₀ (96 h) for rainbow trout >4.7, bluegill sunfish >5.4 mg/l. Environmental fate: Animals:In mammals, following oral administration, chlorthal-dimethyl is metabolised to monomethyl tetrachloroterephthalate and 2,3,5,6-tetrachloroterephthalic acid (chlorthal), which are eliminated in the urine.Soil:Soil DT₅₀ 100 d. In soil, microbial degradation leads to monomethyl tetrachloroterephthalate and 2,3,5,6-tetrachloroterephthalic acid (chlorthal). Duration of residual activity in soil is c. 3 months.Plant:Chlorthal-dimethyl is not metabolised by plants. WATER SOLUBILITY: Approx. 0.5 mg/l at 25° C

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