Alpha-Cypermethrin 100g/L EC

alpha-cypermethrin (197)
Insecticide
pyrethroid

NOMENCLATURE
Common name alpha-cypermethrin (BSI, draft E-ISO); alpha-cyperm閠hrine ((f) draft F-ISO)
IUPAC name A racemate comprising (S)-a-cyano-3-phenoxybenzyl (1R,3R)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate and (R)-a-cyano-3-phenoxybenzyl (1S,3S)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate
Roth: A racemate comprising (S)-a-cyano-3-phenoxybenzyl (1R)-cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate and (R)-a-cyano-3-phenoxybenzyl (1S)-cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate
Chemical Abstracts name [1a(S*),3a]-(?-cyano(3-phenoxyphenyl)methyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate
Other names alfoxylate*; alphamethrin* (rejected common name proposals) CAS RN [67375-30-8] correct stereochemistry; [52315-07-8] (formerly [86752-99-0], [86753-92-6]) cypermethrin (no stereochemistry stated) were sometimes used in Chemical Abstracts Development codes WL 85871 (Shell); FMC 63318; FMC 39391 Official codes OMS 3004

PHYSICAL CHEMISTRY
Composition Tech. grade alpha-cypermethrin is >90% pure m/m, typically >95%. Mol. wt. 416.3 M.f. C22H19Cl2NO3 Form Colourless crystals; (tech. is a white to pale powder, with a weak aromatic odour). M.p. 78-81 篊 B.p. 200 篊/9.3 Pa V.p. 2.3 ?10-2 mPa (20 篊) KOW logP = 6.94 (pH 7) Henry 6.9 ?10-2 Pa m3 mol-1 (calc.) S.g./density 1.28 (22 篊) Solubility In water c. 0.01 mg/l (25 篊). In acetone 620, dichloromethane 550, cyclohexanone 515, ethyl acetate 440, chlorobenzene 420, acetophenone 390, o-xylene 350, hexane 7 (all in g/l, 25 篊). In maize oil 19-20, ethylene glycol <1 (both in g/kg, 20 篊). Stability Very stable in neutral and acidic media. Hydrolysed in strongly alkaline media. Thermally stable up to 220 篊. Field data indicate that, in practice, it is stable to air and light. F.p. >80 篊 (closed cup)

COMMERCIALISATION
History Insecticide reported by J. P. Fisher et al. (Proc. Int. Congr. Plant Prot., 10th, 1983, 1, 452). Introduced by Shell International Chemical Co. (now BASF AG) as WL 85871. Manufacturers Agrochem; BASF; Bharat; FMC; Gharda; Meghmani; Mitsu; Rotam; RPG; Tagros

APPLICATIONS
Mode of action Non-systemic insecticide with contact and stomach action. Acts on the central and peripheral nervous system in very low doses. Uses Control of a wide range of chewing and sucking insects (particularly Lepidoptera, Coleoptera, and Hemiptera) in fruit (including citrus), vegetables, vines, cereals, maize, beet, oilseed rape, potatoes, cotton, rice, soya beans, forestry, and other crops. Control of cockroaches, mosquitoes, flies, and other insect pests in public health; and flies in animal houses. Also used as an animal ectoparasiticide. Formulation types EC; SC; TB; UL; WP. Compatibility Compatible with most organophosphorus insecticides. Selected tradenames: 'Fastac' (agronomic use) (BASF); 'Fendona' (public health use) (BASF); 'Renegade' (veterinary use) (BASF); 'Alphadhan' (Dhanuka); 'Alphaguard' (Gharda); 'Bestox' (FMC); 'Bestseller' (Agriphar); 'Dominex' (FMC); 'Grander' (Sanonda); 'Hurricane' (Nagarjuna Agrichem); 'Stop' (Biostadt)

OTHER TRADENAMES
'Concord' (BASF); 'Contest' (BASF); 'Mageos' (BASF); 'Agro-Cypethrin Super' (AgroSan); 'Alfamar' (Parry); 'Alfathrin' (Papaeconomou); 'Alfazot' (Azot); 'Bala' (FMC); 'Bonsul' (FMC); 'Efitax' (FMC); 'Forward' (RPG); 'Littac' (Sorex); 'Magic' (Vapco); 'Merit Alpha' (Crop Health); 'Pilar-Alfa' (Pilarquim); 'Standon Alpha-C10' (Standon); 'Supertak' (Vapco); 'Vifast' (Vipesco) mixtures: 'Tenopa' (+ flufenoxuron) (Sorex) Discontinued names: 'Acquit' * (Du Pont) mixtures: 'Supercord' * (+ piperonyl butoxide) (Shell)

ANALYSIS
Product analysis of pyrethroids reviewed by E. Papadopoulou-Mourkidou in Comp. Analyt. Profiles. Residues determined by glc with ECD. Details available from BASF.

MAMMALIAN TOXICOLOGY
Reviews JECFA 47 (see part 2 of the Bibliography). See A. J. Gray & D. M. Soderlund, Chapt. 5 in "Insecticides". Oral Acute oral LD50 for rats 79-400 mg/kg (in corn oil, value depending on concentration), 474 mg tech./kg. Skin and eye Acute percutaneous LD50 for rats and rabbits >2000 mg tech./kg; minimal irritant to the eyes of rabbits. Inhalation LC50 (4 h) for rats 0.32 mg/l air. NOEL In 90 d feeding trials, rats receiving 60 mg/kg diet showed no ill-effects. ADI 0.02 mg/kg b.w. (JECFA evaluation) [1996]. Other Non-mutagenic. Toxicity class WHO (a.i.) II; EPA (formulation) II

ECOTOXICOLOGY
Birds LD50 for quail and mallard ducks >10 000 mg/kg. Fish LC50 (96 h) for rainbow trout 0.0028 mg/l; due to rapid loss from water, no toxic effect to fish is observed under field conditions. Daphnia LC50 (48 h) 0.1-0.3 mg/l. Bees Toxic to bees. LD50 (24 h) 0.059 mg/bee. No toxic effect under field conditions. Worms LD50 (14 d) for earthworms >100 mg/kg artificial soil.

ENVIRONMENTAL FATE
EHC 142 (WHO, 1992) EHC 142 notes that, although highly toxic to fish, this is not realised under field conditions where rapid loss from water allows recovery of affected populations. Animals See cypermethrin. Soil/Environment Undergoes degradation in soil, DT50 c. 13 w in loamy soil.