Common name: fenpropathrin; fenpropathrine

IUPAC name: (RS)-a-cyano-3-phenoxybenzyl 2,2,3,3-tetramethylcyclopropanecarboxylate

Chemical Abstracts name: cyano(3-phenoxyphenyl)methyl 2,2,3,3-tetramethylcyclopropanecarboxylate

CAS RN: [64257-84-7] racemate; [39515-41-8] unstated stereochemistry

 

Mol. wt.: 349.4; M.f.: C22H23NO3; Form: Yellow-brown solid (tech.). M.p.: 45-50 ºC; V.p.: 0.730 mPa (20 ºC); KOW: logP = 6 (20 ºC); S.g./density: 1.15 (25 ºC). Solubility: In water 14.1 ug/l (25 ºC). In xylene, cyclohexanone 1000, methanol 337 (all in g/kg, 25 ºC). Stability: Decomposed in alkaline solutions. Exposure to light and air leads to oxidation and loss of activity.

 

Mode of action: Acaricide and insecticide with repellent, and contact and stomach action.

Uses: Control of many species of mites (except rust mites) and insects (e.g. whitefly, lepidopterous larvae, leaf miners, leafworms, bollworms, etc.) on pome fruit, citrus fruit, vines, hops, vegetables, ornamentals (including ornamental trees), cotton, field crops, and glasshouse crops (cucurbits, tomatoes, ornamentals, etc.).

Formulation types: EC; SC; UL; WP.

Compatibility: Incompatible with alkaline materials.

 

Oral: Acute oral LD50 for male rats 70.6, female rats 66.7 mg/kg (in corn oil).

Skin and eye: Acute percutaneous LD50 for male rats 1000, female rats 870, rabbits >2000 mg/kg. Not a skin irritant; mild eye irritant (rabbits). Non-sensitising to skin.

Inhalation: LC50 (4 h) for rats >96 mg/m3.

ADI: 0.03 mg/kg b.w.

Other: Non-mutagenic.

Toxicity class: WHO (a.i.) II; EPA (formulation) II

EC hazard: T+; R26| T; R25| Xn; R21| N; R50, R53

 

Birds: Acute oral LD50 for mallard ducks 1089 mg/kg. Dietary LC50 (8 d) for bobwhite quail and mallard ducks >10 000 mg/kg diet.

Fish: LC50 (48 h) for bluegill sunfish 1.95 ug/l.

 

Soil/Environment: Degraded principally by photolysis, DT50 2.7 w in river water. Duration of activity in soil c. 1-5 d.