Butenachlor is an obsolete selective chloroacetanilide, chloroacetamide herbicide used to control grasses and broadleaf weeds. It was introduced in 1976 and marketed as "Diphenox", by Agro-Kanesho. Butenachlor's mode of action is to prevent formation of very long chain fatty acids; this makes its HRAC classification Group J (Australia), Group K3 (global) and Group 15 (numeric). It is stable in acidic, neutral or weakly alkaline conditions; it is unstable in sublight. Butenachlor is applied at 0.75-1.0 kg/Ha, and usually sold as a pesticide formulation as granules (GR).
Environmental behaviour Butenachlor does not persist in soil; its soil half-life is 2 to 5 days. It is moderately toxic to fish, with a 96-hour LC50 of 0.48 mg/L (0.034 gr/imp. gal).
Safety Butenachlor's acute oral LD50 on rats is 1630 mg/kg (male rats) and 1875 mg/kg (female rates). In mice, it is much less harmful, with an LD50 about 6300 mg/kg. It is slightly irritating to skin and eyes. The inhalatory LC50 for rats is 3.34 mg/L of air over 4 hours. A 90 day NOEL is 25 mg/kg/day for dogs. Butenachlor is non-teratogenic, and has no evident reproductive effects.
References
External links Butenachlor in the Pesticide Properties DataBase (PPDB)