CARBOFURAN

IDENTIFICATION

Common name: Carbofuran

Iupac name: 2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate

Chemical abstracts name: 2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate

Type: Insecticide for Agriculture

CAS RN: [1563-66-2]; (carbofuran phenol [1563-38-8]; 3-ketocarbofuran phenol [17781-16-7])

M.F.: C₁₂H₁₅NO₃

Mol Wt: 221.3

 

M.P.: 153-154℃; (tech., 150-152℃)

V.P.: 0.031 mPa (20℃); 0.072 mPa (25℃)

S.G.: 1.18 (20℃)

Solubility.: In water 320 (20℃), 351 (25℃)(both in mg/l). In dichloromethane>200, isopropanol 20-50, toluene 10-20 (all in g/l,20℃)

Stability: Unstable in alkaline media. Stable in acdic and neutral media. Decomposes>150℃. DT₅₀ (22℃)>>1 y (pH 4), 121 d (pH 7), 31 h (pH 9)

K_owlogP: 1.52 (20℃)

Formulation types: FS;GR;SC;WP

Biochemistry: Cholinesterase inhibitor

Mode of action: Systemic, with predominantly contact and stomach action

Uses: Control of soil-dwelling and foliar-feeding insects (including wireworms, white grubs, millipedes, symphylids, frit flies, bean seed flies, root flies, flea beetles, weevils, sciarid flies, aphids, etc.) and nematodes in vegetables, ornamentals, beet, maize, sorghum, sunflowers, oilseed rape, potatoes, alfalfa, peanuts, soya beabs, sugar cane, rice, cotton, coffee, cucurbits, tobacco, lavender, citrus, vines, strawberries, bananas, mushrooms, and other crops

Compatibility: Incompatible with alkaline materials

Oral: Acute oral LD₅₀ for male and female rats c. 8, dogs 15, mice 14.4 mg/kg.

Skin and eye: Acute percutaneous LD₅₀ (24 h) for mate and female rats >2000 mg/kg; mildly irritating to skin and eyes (rabbits).

Inhalation: LC₅₀ (4 h) for male and female rats c. 0.075 mg/l air (aerosol)

Noel: (2 y) for rats and mice 20 mg/kg diet; (1 y) for dogs 10 mg/kg diet.

ADI: (JMPR) 0.002 mg/kg b.w. [1996].
/Water GV 7 μg/l (based on ADI).

Toxicity: WHO (a.i.) lb; EPA (formulation) I (`Furadan 4F`), II (`Furadan G`) EC hazard T+; R26/28| N; R50, R53

Birds: Acute oral LD₅₀ for Japanese quail 2.5-5 mg/kg. LC₅₀ for Japanese quail 60-240 mg (as GR5)/kg. Tech.: LC₅₀ 0.7-8 mg/kg, depending on species.

Fish: LC₅₀ (96 h) for rainbow trout 22-29 mg (as GR5)/l, bluegill sunfish 1.75 mg (as GR3)/l, golden orfe 107-245 mg (as GR5)/l. Tech.: LC₅₀ 7.3-362.5 μg/l, depending on species.

Daphnia: LC₅₀ (48 h) 38.6 μg/l.

Worms: /Bees: Toxic to bees (except for granular formulation).

Plant: EHC 64 (WHO, 1986; a review of carbamate insecticides in general).
Carbofuran is quickly metabolised into 3-hydroxycarbofuran and ketocarbofuran.

Animals: Carbofuran is metabolised by hydrolytic and oxidative mechanisms in the rat. At 24 hours after treatment, 72% of the dose was eliminated in the urine, 2% in the faeces, and about 43% of the administered dose was hydrolysed. Over 95% of the material excreted in the urine was in the form of conjugated metabolites. The major metabolite was conjugated 3-ketocarbofuran phenol, while conjugated 3-hydroxycarbofuran was the predominant carbamate metabolite. Both metabolites were also present in the free form. Metabolism of carbamate insecticides is reviewed (M. Cool & C. K. Jankowski in "Insecticides").

 

Soil/Environment: DT₅₀ in soil c. 30-60 d. Most important metabolite is CO₂ formed by microbiological degradation of the phenol compounds. K_oc 22.