Detailed Product Description

Fipronil

Common name: Fipronil

Chemical name: 5-amino-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-[(1R,S)-

trifluoromethyl]sulfinyl]-1H-pyrazole-3-carbonitrile

Chemical class: Fiprole

CAS No.: 120068-37-3

Properties:

White solid. M.p. 200-201; (195.5-203). V.p. 3.7×10^-4 mPa (25). In acetone 545.9, dichloromethane 22.3, hezane 0.028, toluene 3.0 (all in g/L, 20 ). Stable in water at pH 5 and 7; slowly hydrolysed at pH 9. Stable to heat. Slowly degrades in sunlight; rapidly photolysed in aqueous solution.

Toxicity:

Acute oral LD₅₀ for rats 97, mice 95 mg/kg. Acute percutaneous LD₅₀ for rat > 2000, rabbits 354 mg/kg. Not a skin or eye irritatant. Not a skin sensitiser. LC₅₀ (4 h) for rats 0.682 mg/L.

Ecotoxicology:

Acute oral LD₅₀ for bobwhite quail 11.3, mallard ducks > 2000, pheasants 31, red-legged partridges 34, house sparrows 1120, pigeons > 2000 mg/kg. Dietary LD₅₀ (5 d) for bobwhite quail 49, mallard ducks >5000 mg/kg diet. LC₅₀ (96 h) for bluegill sunfish 85, rainbow trout 248, European carp 430 μg/L. Daphnia LC₅₀ (48 h) 0.19 mg/L. Highly toxic to honeybees, both by direct contact and by ingestion. However, no risk to bees when used as asoil or seed treatment. Not-toxic to worms.

Environmental fate:

In rats, once absorbed, the distribution and metabolism of fipronil is rapid. Elimination is mainly via the faeces as fipronil and its sulfone. The two major urinary metabolites were identified as conjugates of ring-opened pyrazole products. The distribution of radioactive residues in tissues was extensive after seven days. At crop maturity, the major residue componets observed in all plants were fipronil, the sulfone, and the amide. Following foliar application, at crop maturity, fipronil and the photogradate were the major residue components. In soil, results of lab. And field studies: readily degraded,; major degradates in aerobic soil are sulfone and amide, in anaerobic soil are sulfide and amide. Photolysis of soil-applied fipronil gives the photodegradate together with sulfone and amide. Both fresh and aged column leaching studies indicate that fipronil and its metabolites present a low risk of downward movement in soil.