Nomenclature

Type Insecticide
Common name Chlorfenvinphos
Other name
Iupac name

2-chloro-1-(2,4-dichlorophenyl)vinyl diethyl phosphate 

Formulation type
No Record
Chemical Abstracts Name

2-chloro-1-(2,4-dichlorophenyl)ethenyl diethyl phosphate 

CAS RN [470-90-6]
EEC no
Official code OMS 166; OMS 1328; ENT 24 969
Development code SD 7859 (Shell); C 8949 (Ciba); GC 4072 (Allied); CGA 26351 (Ciba-Geigy); AC 58085 (Cyanamid); BAS 1

Physical Chemistry

M.F.

C12H14Cl3O4P

Structure M
Mol. wt
Appearance

 Colourless liquid; (tech., amber liquid). 

M.p.

-23 to -19 ºC 

B.p.

167-170 ºC/0.5 mmHg 

V.p.

1 mPa (25 ºC); 0.53 mPa (extrapolated to 20 ºC) 

F.p.

No flash point up to 285 °C (EC method AP - ISO 3679) 

 

S.g./density

1.36 at 20 ºC 

Solubility

In water 121 mg/l ((Z)- isomer); 7.3 mg/l ((E)- isomer) (23 ºC). Miscible with most common organic solvents, e.g. ethanol, acetone, dichloromethane, hexane, xylene, propylene glycol, kerosene. 

Stability

Hydrolysed slowly in neutral, acidic, and slightly alkaline aqueous solutions. Hydrolysed rapidly in strongly alkaline solutions. DT50 (38 ºC) >700 h (pH 1.1), >400 h (pH 9.1); (20 ºC) 1.28 h (pH 13). 

Henry
KowlogP

3.85 ((Z)- isomer

Pka

Applications

Biochemistry

Cholinesterase inhibitor. 

Mode of Action

Insecticide and acaricide with contact and stomach action. Long residual activity. 

Uses

Soil application for control of root flies, rootworms, and other soil insects in vegetables; frit flies in maize; wheat bulb flies in wheat; bean seed flies; and phorid and sciarid flies in mushrooms; using granular formulations, applied at 0.8-7 kg/ha. Foliar application for control of Colorado beetles on potatoes; scale insects and mite eggs on citrus fruit; stem borers and leafhoppers on rice; stem borers on maize and sugar cane; and whitefly on cotton; using liquid formulations, applied at 240-2400 g/ha for vegetables and cotton, and up to 12 000 g/ha for ornamentals. Used in public health for control of mosquito larvae. Also used as an animal ectoparasiticide.

Phytotoxicity

Non-phytotoxic when used as directed. Some injury may occur if applied directly to the seeds of certain crops.

Compatibility

Incompatible with alkaline materials.  

General details

Mammalian Toxicology

Reviews

FAO/WHO 71, 73 (see part 2 of the Bibliography).

Oral

Acute oral LD50 for rats 10, mice 117-200, rabbits 300-1000, dogs >12 000 mg/kg.  

Skin & Eye

Acute percutaneous LD50 for rats 31-108, rabbits 400-4700 mg/kg. Non-irritating to skin and eyes (rabbits). 

Inhalation

LC50 (4 h) for rats c. 0.05 mg/l air. 

Noel

(2 y) for rats and dogs 1 mg/kg diet (0.05 mg/kg daily). 

ADI

(JMPR) 0.0005 mg/kg b.w. [1994]. 

Toxicity class

WHO (a.i.) Ib; EPA (formulation) I 

EC hazard

T+; R28| T; R24| N; R50, R53 

Ecotoxicology

Birds

 

BirdsAcute oral LD50 for pheasants 107, pigeons 16 mg/kg. 
Fish

LC50 (96 h) for harlequin fish <0.32, guppies 0.3-1.6, tilapia 0.04 mg/l.  

Daphnia

EC50 (48 h) 0.3 mg/l. 

Algae

EC50 (96 h) for Selenastrum capricornutum 1.6 mg/l. 

Worms

LC50 (14 d) 217 mg/kg of soil. 

Environmental Fate

Plants

Metabolism is similar to that in mammals; see K. I. Beynon et al., Residue Rev., 1973, 47, 55. 

Animals

Primary metabolic detoxification is by de-esterification to give 2-chloro-1-(2,4-dichlorophenyl)vinyl ethyl hydrogen phosphate. Ultimate metabolites include the glucuronides of 2,4-dichlorophenylethanediol and 1-(2,4-dichlorophenyl)ethanol, and N-(2,4-dichlorobenzoyl)glycine; see D. H. Hutson in "Prog. in Pesticide Biochem.", Vol. 1, D. H. Hutson & T. R. Roberts, eds., Wiley (1981). 

Soil/environment

chlorfenvinphos is slowly degraded by hydrolysis; DT50 88 d (pH 9), 270 d (pH 7) ((Z)- isomer); 71 d (pH 9), 275 d (pH 4) ((E)- isomer). In the presence of light, isomerises from the (Z)- to (E)- isomer, DT50 482 h. In soil, chlorfenvinphos is rapidly degraded and apparently mineralised under aerobic conditions; the rate depends on soil characteristics and temperature; DT50 8 d in a sandy loam soil, 161 d in a sand soil (20 °C). 

Miscellaneous

Analysis
Packing