Permethrine;(3-phenoxyphenyl)methyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate

3-phenoxybenzyl (1RS,3RS;1RS,3SR)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate

C₂₁H₂₀Cl₂O₃

Form Yellow-brown to brown liquid, which sometimes tends to crystallise partly at room temperature.

Melting point 34-35℃; cis- isomers 63-65℃; trans- 44-47℃.

Density 1.29 (20℃). Solubility In water 6×10^-3 mg/l (pH 7, 20℃. In xylene, hexane >1000, methanol

258 (all in g/kg, 25℃).

Oral Oral LD50 values of permethrin depend on such factors as: carrier, cis/trans ratio of the sample, the test species, its sex, age and degree of fasting; values reported sometimes differ markedly. Values for a cis/trans ratio of c. 40:60 are: for rats 430-4000, mice 540-2690 mg/kg; with a 20:80 ratio, the LD50 is c. 6000 mg/kg.

Skin and eye Acute percutaneous LD50 for rats >2500, rabbits >2000 mg/kg.

Mild eye and skin irritant (rabbits). Moderate skin sensitiser.

Inhalation LC50 (3 h) for mice and rats >685 mg/m³ air; (separate study gives >13800 mg/m3).

A contact insecticide effective against a broad range of pests. It controls leaf- and fruit-eating Lepidoptera and Coleoptera in cotton,in fruit,in tobacco,vines and other crops,and in vegetables. It has good residual activity on treated plants.

Description: Amber viscous liquid;

Active Ingredient Content (w/w): ≥95%;

Water (w/w): ≤0.15%; Acidity (as HCl ): ≤0.2%;

Loss on Drying (w/w): ≤0.1%;

Cis/Trans: 25:75