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DESIGNATIONS
CAS No.: 62-73-7
Registry name: Dichlorvos
Chemical name: 2,2-Dichlorovinyl dimethyl phosphate
Synonyms, Trade names: 2,2-Dichloroethenyl dimethyl phosphate, O,O-dimethyl O-(2,2-dichlorovinyl) phosphate, DDVP, Nuvan, Vapona
Chemical name (German): Dichlorvos
Chemical name (French): Dichlorvos
Appearance: colourless to yellowy liquid
BASIC CHEMICAL AND PHYSICAL DATA
Empirical formula: |
C4H7Cl2O4P |
Rel. molecular mass: |
220.98 g |
Density: |
1.314 g/cm3 |
Relative gas density: |
7.63 |
Boiling point: |
74°C (at 1.32 hPa) |
Vapour pressure: |
1.6 Pa |
Solvolysis/solubility: |
in water: » 10 g/l miscible with most organic solvents |
Conversion factors: |
1 ppm = 9.19 mg/m3 1 mg/m3 = 0.11 ppm |
ORIGIN AND USE
Usage:
Dichlorvos is an insecticide that mainly acts via the gas phase due to its relatively high
vapour pressure. It may also be used as a contact insecticide. Dichlorvos is applied in
form of aerosols or baits against flies and mosquitos.
Toxicity
Mammals: |
||
Rat: |
LD50 56-108 mg/kg, oral |
acc. WHO, 1986 |
Rat: |
LD50 75-210 mg/kg, dermal |
acc. WHO, 1986 |
Rat: |
LD50 56-80 mg/kg, oral |
acc. WIRTH, 1981 |
Aquatic organisms: |
||
Carp: |
TLM > 40 mg/l (48 h) |
acc. WHO, 1986 |
Goldfish: |
TLM 10-40 mg/l (48 h) |
acc. WHO, 1986 |
Water flea: |
TLM 2.8 mg/l (3 h) |
acc. WHO, 1986 |
Characteristic effects:
Humans/mammals: Intake takes place either by inhalation or via the gastro-intestinal tract. As is the case with phosphoric acid esters, dichlorvos is only slightly resorbed in the body. Above all, dichlorvos inhibits acetylcholinesterase and thus impairs the central nervous system. The symptoms are comparable to those of paraquat. According to WIRTH (1981), dichlorvos does not represent a genetic risk.
ENVIRONMENTAL STANDARDS
Medium/ acceptor |
Sector |
Country/ organ. |
Status |
Value |
Cat. |
Remarks |
Source |
Air: |
Workp |
D |
L |
1 mg/m3 |
MAK | DFG, 1989 | |
Workp |
SU |
(L) |
0.2 mg/m3 |
PDK | Skin | acc. KETTNER, 1979 | |
Workp |
USA |
(L) |
1 mg/m3 |
TWA | ACGIH, 1986 | ||
Foodstuffs: |
WHO |
G |
0.004 mg/kg/d |
ADI | acc. WHO, 1986 |
Assessment/comments
Dichlorvos is one of the organophosphoric insecticides for which the residue problems are similar to those of halogenated insecticides. Direct contact with dichlorvos is to be avoided on account of the fact that it inhibits the respiratory system.