IDENTIFICATION
Common name: Deltamethrin
Iupac name: (S)-0t-cyano-3-phenoxybenzyl (1R,3R)-3-(2,2-dibromovinyl)-2,2- dimethylcyclopropanecarboxylate
Chemical abstracts name: [1R-[1α(S*),3α]]-cyano(3-phenoxyphenyl)methyl 3-(2, 2-dibromoethenyl)-2,2-dimethylcyclopropanecarboxylate
Type: Insecticide for Agriculture
CAS RN: [52918-63-5]; [52820-00-5] ((RS)- (1R)-cis- isomer pair)
Mol Wt: 505.2
PHYSICAL CHEMISTRY
Form (appearance): contains >98% deltamethrin (i.e. the single isomer).
Colourless crystals
Composition:=Tech. produced industrially by Aventis
M.P.:100-102℃
V.P.: 1.24 × 10-5 mPa (25℃, gas saturation method)
S.G.: Bulk density 0.55 g/cm3 (25℃)
Solubility: In water <0.2 μg/l (25℃). In dioxane 900, cyclohexanone 750, dichloromethane 700, acetone 500, benzene 450, dimethyl sulfoxide 450, xylene 250, ethanol 15, isopropanol 6 (all in g/l,20℃)
Stability: Extremely stable on exposure to air. Stable < 190℃. Under u.v. irradiation and in sunlight, a cis-trans isomerisation, splitting of the ester bond, and loss of bromine occur. More stable in acidic than in alkaline media; DT50 2.5 d (pH 9, 25℃). Specific rotation [α][X|D|X] +610 (40 g/l benzene)
Henry: 3.13 x 10-2 Pa m3 mol-1 (calc.)
KowlogP: 4.6 (25℃)
APPLICATION
Formulation types: DP; EC; EG; EW; GR; HN; PO; SC; SL; TB; UL; WG; WR
Biochemistry: Like all pyrethroids, prevents the sodium channels from functioning, so that no transmission of nerve impulses can take place
Mode of action: NonIsystemic insecticide with contact and stomach action. Fast-acting
Uses: A potent insecticide, effective by contact and ingestion against a wide range of pests. Crop protection uses include: Coleoptera (2.5-7.5 g/ha), Heteroptera (5.0-7.5 g/ha), Homoptera (6.2-12.5 g/ha), Lepidoptera (5.0-21 g/ha) and Thysanoptera (5-10 g/ha) in cereals, citrus, cotton, grapes, maize, oilseed rape, soya beans, top fruit and vegetables. It controls Acrididae (5.0-12.5 g/ha), and is recommended against locusts. Soil surface sprays (2.5-5.0 g/ha) control Noctuidae. It is used against indoor crawling and flying insects (12.5 mg/m2) and pests of stored grain (0.25-0.5 g/t) and timber (Blattodea, Culicidae, Muscidae). Dip or spray (12.5-75 mg/l), and pourIon (0.75 mg/kg b.w.) applications give good control of Muscidae, Tabanidae, Ixodidae and other Acari on cattle, sheep and pigs, etc
MAMMALIAN TOXICOLOGY
Oral: Acute oral LD50 for rats ranges from 135 to >5000 mg/kg (depending upon carrier and conditions of the study); for dogs >300 mg/kg. Acute oral LD50 for formulations in rats: >2000 mg (of 15 g/l EC)/kg; 445 mg (of 25 g/l EC)/kg; >5000 mg (of 5 g/l UL)/kg; >16000 mg (of 25 g/kg WP)/kg; >40000 mg (of 25 g/l SC)/kg.
Skin and eye: Acute percutaneous LD50 for rats and rabbits >2000 mg/kg. Non-irritating to skin; mild eye irritant (rabbits).
Inhalation: LC50 (4 h) for rats 2.2 mg/l air; (1 h) >4.6 mg/l air (micronised).
Noel: (2 y) for mice 12, rats 1, dogs 1 mg/kg b.w.
ADI: (JMPR) 0.01 mg/kg b.w. [1982].
Other Non-mutagenic and non-teratogenic (mice, rats, rabbits).
Toxicity: WHO (a.i.) II; EPA (formulation) II
ECOTOXICOLOGY
Birds: Acute oral LD50 for mallard ducks >4640 mg/kg. Dietary LC50 (8 d) for mallard ducks >8039, quail >5620 mg/kg diet. NOEL for reproduction for mallard ducks >70, bobwhite quail >55 mg/kg daily.
Fish: Toxic to fish under laboratory conditions; LC50 (96 h) for rainbow trout 0.91, bluegill sunfish 1.4 μg/l. Not toxic to fish under natural conditions.
Daphnia: LC50 (48 h) 3.5 μg/l.
Algae: EC50 (96 h) for algae (Selenastrum capricornutum) >9.1 mg/l. Low LD50 and LC50 values under laboratory conditions do not represent a significant hazard to aquatic fauna in normal field use.
Worms: LC50 (14 d) for earthworms >1290 mg/kg soil.
Bees: Toxic to bees, LD50 (oral) 79 ng/bee; (contact) 51 ng/bee. Low LD50 and LC50 values under laboratory conditions do not represent a significant hazard to bee: in normal field use.
ENVIRONMENTAL FATE
Plant: No uptake through leaves and roots-non-systemic compound. No major metabolites, except in oily crops, where trans-deltamethrin is part of the residue definition.
Animals: In rats, following oral administration, elimination occurs within 2-4 days. The phenyl ring is hydroxylated, the ester bond hydrolysed, and the acid moiety is eliminated as the glucuronide and glycine conjugates.
Soil/Environment: In soil, undergoes microbial degradation within 1-2 weeks. Kd 3790-30000, Koc 4.6 × 105 -1.63 × 107 cm3/g, confirms strong adsorption by soil colloids and no risk of leaching. DT50 (lab., aerobic) 21-25 d, (anaerobic) 31-36 d. In field, DT50 <23 d. Soil photolysis DT50 9 d. No incidence on soil microfiora and nitrogen cycle. |
