PHYSICAL CHEMISTRY Emamectin Benzoate

emamectin benzoate

Composition A mixture of emamectin B 1a ( 3 90%) and emamectin B 1b ( ? 10%), as their benzoate salts. Mol. wt. 1008.3 (B 1a ); 994.2 (B 1b ) M.f. C 56 H 81 NO 15 (B 1a ); C 55 H 79 NO 15 (B 1b ) Form White to off-white powder. M.p. 141-146 °C V.p. 4 ' 10 -3 mPa (21 °C) K OW logP = 5.0 (pH 7) S.g./density 1.20 (23 °C) Solubility In water 0.024 g/l (pH 7, 25°C).

emamectin

Mol. wt. 886.1 (B 1a ); 872.1 (B 1b ) M.f. C 49 H 75 NO 13 (B 1a ); C 48 H 73 NO 13 (B 1b )

COMMERCIALISATION Emamectin Benzoate

History Discovery and initial development was by Merck & Co., Inc. (now Syngenta AG). First sales in Israel and Japan in 1997. Manufacturers Merck & Co.

APPLICATIONS Emamectin Benzoate

emamectin benzoate

Mode of action Non-systemic insecticide which penetrates leaf tissues by translaminar movement. Uses For control of Lepidoptera on vegetables, brassicas and cotton, at up to 16 g/ha, and in pine trees, at 5-25 g/ha. Formulation types EC; SG.

ANALYSIS Emamectin Benzoate

Product and residues determined by hplc. Details available from Syngenta.

MAMMALIAN TOXICOLOGY Emamectin Benzoate

emamectin benzoate

Oral Acute oral LD 50 for rats 76-89 mg/kg. Skin and eye Acute dermal LD 50 for rabbits >2000 mg/kg. It is not irritant to skin, and has no sensitising potential. Inhalation LC 50 (4 h) for rats 2.12-4.44 mg/m 3 . NOEL (1 y) for dogs 0.25 mg/kg b.w. ADI 0.0025 mg/kg. Other Not tumorigenic. Toxicity class WHO (a.i.) II

ECOTOXICOLOGY

emamectin benzoate

Birds Acute oral LD 50 for mallard ducks 46, bobwhite quail 264 mg/kg. Dietary LC 50 (8 d) for mallard ducks 570, bobwhite quail 1318 ppm. Fish LC 50 (96 h) for rainbow trout 174, sheepshead minnow 1430 m g/l. Daphnia LC 50 0.99 m g/l. Algae >94 m g/l. Bees Toxic to bees. Worms >1000 mg/kg.

ENVIRONMENTAL FATE Emamectin Benzoate

Animals Emamectin benzoate is partially metabolised but rapidly cleared (DT 50 following oral dosing 34-51 h), indicating that it has no potential for bioaccumulation. Plants Metabolism has been investigated in lettuce, cabbage and sweet corn. It is non-systemic, and rapidly degrades in sunlight to various complex residues in which undegraded parent is the only significant residue. The residues were very low. Soil/Environment Rapidly degraded