| Chemical Abstract Number (CAS #) |
470906
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| Synonyms | Chlorfenvinphos |
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Supona | Phosphoric acid, 2-chloro-1-(2,4-dichlorophenyl) vinyl dimethyl ester |
| Analytical Method |
EPA Method 8141A |
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| Molecular Formula | C12H14Cl3O4P |
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| Use | INSECTICIDE; ACARICIDE
/IT IS USED FOR CONTROL OF TICKS, FLIES, LICE & MITES ON CATTLE &
BLOWFLY, LICE, KED, & ITCHMITE ON SHEEP.
/IT IS INSECTICIDE FOR CONTROL OF ROOT FLIES, ROOTWORMS AND
CUTWORMS AT 2-4 KG/HECTARE. IT IS FOLIAGE INSECTICIDE FOR CONTROL OF
COLORADO BEETLE ON POTATOES AND LEAF HOPPERS ON RICE AT 0.2-0.5
KG/HECTARE AND STEM BORERS IN MAIZE, SUGAR CANE AND RICE AT 0.5-2.0
KG/HECTARE.
/IT IS USED AGAINST TICKS AND FLIES ON HORSES, GOATS AS WELL AS
FLEAS ON DOGS, AND ON ORGANIC WASTES AND BREEDING PLACES OF FLY
LARVAE INCLUDING DAIRYBARNS. DO NOT USE ON CATS.
Nematocide, parasiticide
Soil application or seed treatment for control of fruit flies in maize; wheatbulb flies in wheat;
bean seed flies; and phorid and sciarid flies in mushrooms.
Chlorfenvinphos may be used either as a soil insecticide for the control of cutworms, root flies
and root worms at 2-4 kg ai/hectare or as a foliar insecticide to control Leptinotarsa decemlineata
on potato, scale insects on citrus at 200-400 g/ha where it also exhibits ovicidal activity against
mite eggs, and of stem borers on maize, rice and sugarcane at 550-2200 g/hectare. It controls
whiteflies (Bemisia species) on cotton at 400-750 g/hectare but whitefly parasites are not affected.
It also controls ectoparasites (Dalmania bovis, Bovicola bovis and Haematopinus quadripertusus)
of cattle at 0.3-0.7 g/l, and Lucilia sericata and Ixodes ricinus of sheep at 0.5 g/l and D. ovis,
Melphagus ovinus and Linognathus ovillus at 0.1 g/l. Chlorfenvinphos may also be used in public
health programs especially against mosquito larvae.
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| Apparent Color | Colorless liquid
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| Odor | MILD ODOR
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| Boiling Point | 167-170 DEG C AT 0.5 MM HG
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| Melting Point | -19 TO -23 DEG C
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| Molecular Weight | 359.56
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| Density | 1.36 G/CU CM AT 20 DEG C
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| Environmental Impact | Chlorfenvinphos's use as a soil and foliar insecticide releases the compound directly to
the environment through applications in sprays and other routes of application. If released to the
atmosphere, clorfenvinphos will degrade rapidly in the vapor phase by reaction with
photochemically produced hydroxyl radicals (half-life of about 7 hr). Particulate phase
chlorfenvinphos and aerosols released to air during spray applications of chlorfenvinphos
insecticides will be removed from air physically by dry and wet deposition. If released to soil or
water, chlorfenviphos will degrade through biodegradation. The importance of microbial
degradation has been demonstrated by various persistence studies that compare degradation rates
in sterile versus nonsterile soil; in these studies, degradation of chlorfenvinphos is much faster in
nonsterile soil than in sterile soil. In one 90-day field study, chlorfenvinphos did not leach in a
sandy loam soil. Typical soil half-lives range from roughly 10 to 45 days. Occupational exposure
tochlorfenviphos occurs through dermal contact and inhalation of sprays, especially to workers
applying the compound as an insecticide. Since chlorfenviphos has been detected in U.S. foods,
exposure to the general population may occur through consumption of foods containing
chlorfenviphos residues.
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| Environmental Fate | CHLORFENVINPHOS WAS APPLIED TO SLOPING ARABLE LAND AT THE
RATE OF 22 KG ACTIVE INGREDIENT/HECTARE. ONLY SMALL QUANTITIES
APPEARED AT BOTTOM OF SLOPE. NO RESIDUES WERE DETECTED IN A POND AT
BOTTOM OF SLOPE AT 23 WEEKS AFTER APPLICATION.
TERRESTRIAL FATE: Biodegradation appears to be the dominant degradation process in soil.
The importance of microbial degradation has been demonstrated by various persistence studies
that compare degradation rates in sterile versus nonsterile soil(1-3); in these studies, degradation
of chlorfenviphos is much faster in nonsterile soil than in sterile soil(1-3). One measured Koc
value of 295 suggests medium soil mobility; however, chlorfenviphos can be adsorbed strongly
by clay particles , and the results of one field study in a sandy loam soil indicated that
chlorfenviphos did not leach(6). Chlorfenviphos applied to plant surfaces has been observed to
volatilize(7); therefore, in the absence of strong adsorption, volatilization from plant and soil
surfaces may be an important transport mechanism.
TERRESTRIAL FATE: In field studies conducted during the growing of cauliflower crops, 70
to 98% of the chlorfenviphos initially applied disappeared after 43-57 days in four different
Belgium soils ; the following chlorfenviphos metabolites were identified :
2,4-dichlorophenacyl chloride; 2,4-dichloroacetophenone; alpha-chloromethyl-2,4-dichlorobenzyl
alcohol; 1-(2'-4'-dichlorophenyl)-ethan-1-ol; 2,4-dichlorobenzoic acid; 2-hydroxy-4-chlorobenzoic
acid; 2,4-dihydroxybenzoic acid . In field studies conducted during 1986 and 1987, the soil
half-life of chlorfenviphos ranged from 9 to 30 days in fields growing caulifower, Brussel sprouts
and cabbage ; degradation occurred faster in fields with prior exposure to chlorfenviphos
suggesting a microbial adaptation mechanism . In greenhouse studies, the initial half-life of
chlorfenviphos applied to potato, cabbage and maize foliage was 2 to 3 days, after which the
disappearance rate decreased ; the rapid initial rate was probably due to volatilization from
plant surfaces . In a field study conducted in India in a sandy loam soil, a soil half-life of 33.1
days was observed .
TERRESTRIAL FATE: In laboratory studies, soil half-lives of about 6 days were observed in
soil treated only once ; in soils treated several times previously with chlorfenviphos, half-lives of
about 3 days were observed . An approximate soil half-life of 14 to 161 days has been
reported . The soil persistence half-life of chlorfenviphos was reported to range from 0.5 to 1.5
months .
AQUATIC FATE: Biodegradation may be the dominant degradation process in natural water.
One screening study has shown that chlorfenviphos biodegrades in natural water and sewage .
In addition, various screening studies have demonstrated that microbial degradation is the
dominant degradation process in soil(2-4). The persistence of chlorfenviphos (complete
degradation) in one river die-away test ranged from 17 to 33 days at concns of 5-15 mg/cu
decimeter . Aquatic hydrolysis and volatilization are not expected to be important fate
processes. Based upon hydrolysis studies conducted at 70 deg C , the aqueous hydrolysis
half-life of chlorfenviphos at 20 deg C (and pH range of 6-8) is roughly 1 to 1.3 yrs(6,SRC).
ATMOSPHERIC FATE: Based upon a reported vapor pressure of 4X10-6 mm Hg at 20 deg
C , chlorfenivphos can exist in both the vapor and particulate phases in the ambient atmosphere,
although the vapor phase can be expected to dominate(2,SRC). It will degrade rapidly in the
vapor phase by reaction with photochemically produced hydroxyl radicals with an estimated
half-life of about 7 hr(3,SRC). Particulate phase chlorfenviphos and aerosols released to air during
spray applications of chlorfenivphos insecticides will be removed from air physically by dry and
wet deposition.
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| Drinking Water Impact | CHLORFENVINPHOS WAS APPLIED TO SURFACE OF POND AT A RATE
THAT GAVE AVG CONCN OF 6.1 PPM. AFTER 5 HR THIS HAD DECREASED TO 2.0
PPM AND TO 0.12 PPM AFTER 1 MONTH. RESIDUES IN MUD REACHED MAX OF 0.32
PPM 115 HR AFTER TREATMENT AND PERSISTED FOR AT LEAST 34 DAYS.
EFFL: In one reported field study, 0.3-0.6% of applied chlorfenviphos was found in runoff water
from rainfall .
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