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Insecticide Chlorfluazuron
NOMENCLATURE Chlorfluazuron
Common name chlorfluazuron (BSI, draft E-ISO, (m) draft F-ISO)
IUPAC name 1-[3,5-dichloro-4-(3-chloro-5-trifluoromethyl-2-pyridyloxy)phenyl]-3-(2,6-difluorobenzoyl)urea
Chemical Abstracts name N-[[[3,5-dichloro-4-[[3-chloro-5-(trifluoromethyl)-2-pyridinyl]oxy]phenyl]amino]carbonyl]-2,6-difluorobenzamide
CAS RN [71422-67-8] Development codes IKI-7899 (Ishihara Sangyo); CGA 112 913 (Ciba-Geigy); PP145 (ICI); UC 64 644 (Rhône-Poulenc)
PHYSICAL CHEMISTRY Chlorfluazuron
Composition Tech. is ³94.0%. Mol. wt. 540.7 M.f. C20H9Cl3F5N3O3 Form White crystals. M.p. 226.5 ºC (decomp.) V.p. <1 ´ 10-5 mPa (20 ºC) KOW logP = 5.8 (unionised) Henry <5.41 ´ 10-4 Pa m3 mol-1 S.g./density 1.663 (20 °C) Solubility In water <0.01 mg/l (20 ºC). In hexane <0.01, n-octanol 1, xylene 2.5, methanol 2.5, toluene 6.6, isopropanol 7, dichloromethane 22, acetone 55, cyclohexanone 110 (all in g/l, 20 ºC). Stability Stable to heat and light, and to hydrolysis. pKa 8.10, v. weak acid F.p. 224.0-224.5 °C (OECD 102)
APPLICATIONS Chlorfluazuron
Biochemistry Chitin synthesis inhibitor (R. Neumann & W. Guyer, Proc. 10th Int. Congr. Plant Prot., 1983, 1, 445). Mode of action Insect growth regulator which acts as an anti-moulting agent, leading to death of the larvae and pupae. Uses Control of Heliothis, Spodoptera, Bemisia tabaci and other chewing insects on cotton; and Plutella, Thrips and other chewing insects on vegetables. Also used on fruit, potatoes, ornamentals and tea. Applied at 2.5 g/hl. Formulation types EC; SC; UL. Selected tradenames: 'Aim' (Ishihara Sangyo); 'Atabron' (Ishihara Sangyo, Syngenta); 'Jupiter' (Ishihara Sangyo)
MAMMALIAN TOXICOLOGY Chlorfluazuron
Oral Acute oral LD50 for rats >8500, mice 7000 mg/kg. Skin and eye Acute percutaneous LD50 for rats >1000, rabbits >2000 mg/kg. Non-irritating to skin; mild eye irritant (rabbits). Not a skin sensitiser. Inhalation LC50 (4 h) for rats >2.4 mg/l. Other Non-mutagenic in the Ames test. Toxicity class WHO (a.i.) III (Table 5)
ECOTOXICOLOGY Chlorfluazuron
Birds Acute oral LD50 for quail and mallard ducks >2510 mg/kg. Dietary LC50 (8 d) for quail and mallard ducks >5620 mg/kg diet. Fish LC50 (48 h) for carp >300 mg/l. Daphnia LC50 (48 h) 0.908 mg/l. Algae EC50 (12 d) for green algae >1.8 mg/l. Bees LD50 (oral) >100 mg/bee. Worms LC50 (28 d) for earthworms >1000 mg/kg soil.
ENVIRONMENTAL FATE Chlorfluazuron
Animals Metabolised in rats by cleavage of the urea bridge. Plants Slowly degraded in plants. Soil/Environment Half-life in soil varies from c. 6 weeks to a few months. Kd 120-990. Slowly degraded in water, DT50 for aqueous photodegradation 20 h. |
