CARBARYL
IDENTIFICATION
Common name: Carbaryl
Other name: carbaryl (BSI, E-ISO, (m) F-ISO, ANSI, ESA, BAN); NAC (JMAF); sevin* (former exception, USSR)
Iupac name: 1-naphthyl methylcarbamate
Chemical abstracts name: 1-naphthalenyl methylcarbamate
Type: Insecticide for Agriculture
CAS RN: [63-25-2]
M.F.: C12H11NO2
Mol Wt: 201.2
PHYSICAL CHEMISTRY
Form (appearance): Colourless to light tan crystals
M.P.: 142℃
V.P.: 4.1×10-2 mPa (23.5℃)
S.G.: 1.232 (20℃)
Solubility.:In water 120 mg/l (20℃) .Readily soluble in polar organic solvents. In dimethylformamide, dimethyl sulfoxide 400-450, acetone 200-300, cyclohexanone 200-250, isopropanol 100, xylene 100 (all in g/kg, 25℃)
Stability: Stable under neutral and weakly acidic conditions. Hydrolysed in alkaline media to 1-naphthol; DT50 c. 12 d (pH 7), 3.2 h (pH 9). Stable to light and heat
KowlogP: 1.59
APPLICATION
Formulation types: DP;GR;OF;RB;SC;TK;WP
Biochemistry: Weak cholinesterase inhibitor
Mode of action: Insecticide with contact and stomach action, and slight systemic properties
Uses: Control of Lepidoptera, Coleoptera, and other chewing and sucking insects, at 0.25-2.0 kg a.i./ha, on more than 120 different crops, including vegetables, tree fruit (including citrus), mangoes, bananas, strawberries, nuts, vines, olives, okra, cucurbits, peanuts, soya beans, cotton, rice, tobacco, cereals, beet, maize, sorghum, alfalfa, potatoes, ornamentals, forestry, etc. Control of earthworms in turf. Used as a growth regulator for fruit thinning of apples. Also used as an animal ectoparasiticide
Phytotoxicity: Non-phytotoxic if used as directed. Under certain conditions, some varieties of apple and pear may be injured
MAMMALIAN TOXICOLOGY
Reviews: FAO/WHO 77, 79 (see part 2 of the Bibliography).
/IARC ref. 12; class 3
Oral: Acute oral LD50 for male rats 850, female rats 500, rabbits 710 mg/kg.
Skin and eye: Acute percutaneous LD50 for rats >4000, rabbits >2000 mg/kg. Non-irritating to skin and eyes (rabbits).
Inhalation: LC50 for rats >206.1 mg/l air.
Noel: (2 y) for rats 200 mg/kg diet.
ADI: (JMPR) 0.003 mg/kg b.w. [1996].
Toxicity: WHO (a.i.) II; EPA (formulation) I (`Tercyl` 85WP), II (`Sevin` 80S), III
EC hazard: R40| Xn; R22| N; R50
ECOTOXICOLOGY
Birds: Acute oral LD50 for young mallard ducks >2179, young pheasants >2000, Japanese quail 2230, pigeons 1000-3000 mg/kg.
Fish: LC50 (96 h) for rainbow trout 1.3, sheepshead minnow 2.2, bluegill sunfish 10 mg/l.
Daphnia: LC50 (48 h) 0.006 mg/l.
/Other aquatic spp, LC50 (96 h) for mysid shrimp (Mysidopsis bahia) 5.7 μg/l; LC50 (48 h) for Eastern oyster (Cmssostrea virginica) 2.7 mg/l.
Worms: /Bees: Toxic to bees: LDs0 (topical) 1μg/bee.
/Other beneficial spp. Toxic to beneficial insects.
ENVIRONMENTAL FATE
Plant: EHC 153 (WHO, 1994); 64 (WHO, 1986; a review of carbamate insecticides in general).
Metabolites are 4-hydroxycarbaryl, 5-hydroxycarbaryl and methylol-carbaryl.
Animals: In mammals, carbaryl does not accumulate in body tissues, but is rapidly metabolised to non-toxic substances, particularly 1-naphthol. This, together with the glucuronic acid conjugate, is eliminated predominantly in the urine and faeces. Metabolism of carbamate insecticides is reviewed (M. Cool & C. K. Jankowski in "Insecticides").
Soil/Environment: Under aerobic conditions, carbaryl at 1 ppm degraded with DT50 7-14 d in a sandy loam and 14-28 d in a clay loam.
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