Specification :

Permethrin

Common name: permethrin; permé thrine
IUPAC name: 3-phenoxybenzyl ( 1RS, 3RS; 1RS, 3SR) -3-( 2, 2-dichlorovinyl) -2, 2-dimethylcyclopropanecarboxylate
Roth: 3-phenoxybenzyl ( 1RS) -cis-trans-3-( 2, 2-dichlorovinyl) -2, 2-dimethylcyclopropanecarboxylate
Ch emical Abstracts name: ( 3-phenoxyphenyl) methyl 3-( 2, 2-dichloroethenyl) -2, 2-dimethylcyclopropanecarboxylate
CAS RN: [ 52645-53-1] , ( formerly [ 57608-04-5] and [ 63364-00-1] )

PHYSICAL CHEMISTRY
Mol. wt.: 391.3, M.f.: C21H20Cl2O3; Form: Tech. is a yellow-brown to brown liquid, which sometimes tends to crystallise partly at room temperature. M.p.: 34-35 º C; cis- isomers 63-65 º C; trans- 44-47 º C. B.p.: 200 º C/ 0.1 mmHg; > 290 º C/ 760 mmHg. V.p.: cis- 0.0025 mPa; trans- 0.0015 mPa ( both 20 º C) . KOW: logP = 6.1 ( 20 º C) . S.g./ density: 1.29 ( 20 ° C) . Solubility: In water 6x10-3 mg/ l ( pH 7, 20 º C) . In xylene, hexane > 1000, methanol 258 ( all in g/ kg, 25 º C) . Stability: Stable to heat ( 2 y at 50 º C) , more stable in acidic than alkaline media with optimum stability c. pH 4; DT50 50 d ( pH 9) , stable ( pH 5, 7) ( all 25 ° C) . Some photochemical degradation observed in laboratory studies, but field data indicate this does not adversely affect biological performance. F.p. > 100 º C ( ' Perigen' ) .

APPLICATIONS
Mode of action: Non-systemic insecticide with contact and stomach action, having a slight repellent effect.
Uses: A contact insecticide effective against a broad range of pests. It controls leaf- and fruit-eating Lepidoptera and Coleoptera in cotton, at 100-150 g a.i./ ha, in fruit, at 25-50 g/ ha, in tobacco, vines and other crops, at 50-200 g/ ha, and in vegetables, at 40-70 g/ ha. It has good residual activity on treated plants. It is effective against a wide range of animal ectoparasites, provides > 60 d residual control of biting flies in animal housing, at 200 mg a.i. ( as EC) / m2 wall or 30 mg a.i. ( as WP) / m2 wall, and is effective as a wool preservative, at 200 mg/ kg wool. It provides > 120 d control of Blattodea, Diptera, Hymenoptera and other crawling insects, at 100 mg a.i. ( as WP) / m2, also flying insects.
Phytotoxicity: Non-phytotoxic when used as directed ( except that some ornamentals may be injured) .
Formulation types: DP; EC; UL; WG; WP; Fumigant; Aerosol.
Compatibility: Mixing with calcium nitrate is not recommended.

MAMMALIAN TOXICOLOGY
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 > 13 800 mg/ m3) .
NOEL: In 2 y feeding trials, rats receiving 100 mg/ kg diet showed no ill-effects.
ADI: 0.05 mg/ kg b.w. ( for tech., with cis/ trans ratios 25: 75 to 40: 60)
Water GV: 20 ug/ l ( based on ADI) .
Other: No mutagenic, teratogenic, or carcinogenic activity.
Toxicity class: WHO ( a.i.) II; EPA ( formulation) II ( ' Ambush' ) ; III ( ' Outflank' )
EC hazard: Xn; R22

ECOTOXICOLOGY
Birds: Typical oral LD50 values for a cis/ trans ratio of c. 40: 60 are: for chickens > 3000, mallard ducks > 9800, Japanese quail > 13 500 mg/ kg.
Fish: LC50 ( 96 h) for rainbow trout 2.5 ug/ l; ( 48 h) for rainbow trout 5.4, bluegill sunfish 1.8 ug/ l.
Daphnia: LC50 ( 48 h) 0.6 ug/ l.
Bees: Toxic to bees. LD50 ( 24 h) ( oral) 0.098 ug/ bee; ( topical) 0.029 ug/ bee.

ENVIRONMENTAL FATE
EHC: Permethrin is not likely to be a hazard to the environment when used as recommended.
Animals: In mammals, there is hydrolysis of the ester bond, hydroxylation, and elimination as the glucoside conjugate.
Soil/ Environment: In soil and water, degradation is rapid. DT50 in soil