| Chemical Abstract Number (CAS #) |
133062
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| Synonyms | Captan |
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4-Cyclohexene-1,2-dicarboximide N-(trichloromethyl)thio- | Orthocide-406 | SR-406 | Vancide-89 |
| Analytical Methods |
EPA Method 617 |
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EPA Method 8081 |
| Molecular Formula | C9H8Cl3NO2S |
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| Use | PRESERVATIVE FOR COSMETICS (EG, NON-COLORING HAIR PRODUCTS).
/FUNGICIDE USED TO CONTROL: CONTROLS SCAB, BLACK ROT, BOTRYTIS,
SOOTY BLOTCH, FLY SPECK, & SUMMER ROTS ON APPLES; BROWN ROT & LEAF
SPOTS ON STONE FRUITS & ALMONDS; DEAD ARM, DOWNY MILDEW, & BLACK
ROT ON GRAPES. CONTROLS A WIDE VARIETY OF FUNGUS DISEASES ON SMALL
FRUITS, BERRIES, ORNAMENTALS & VEGETABLES. SEED TREATMENT BY
SLURRY, DRY TREATMENT, AND PLANT-BOX APPLICATION.
Household uses include: application to fruit, vegetable and ornamental gardens, house plants and
lawns, in paints (oil based), on surfaces (awnings, blankets, boats, closets, clothing, draperies,
floors, leather goods, luggage, mattresses, rugs, shoes, storage rooms, upholstery, walls,
workshops), and on other articles. Industrial uses include incorporation into lacquers, paints (oil
based), paper, paste (wallpaper flour), plasticizers, polyethylene, rubber stabilizer, textiles, vinyl,
and vinyl resins.
/FORMER USE: APPLICATIONS (VET): AS BACTERIOSTAT & FUNGICIDE
Although captan has reportedly been used as a plant regulator on citrus fruit, no evidence was
found that it is currently used for this purpose in the USA.
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| Consumption Patterns | FUNGICIDE FOR APPLES, 45%; OTHER DECIDUOUS FRUIT, 33%; SEED
TREATMENT OF FIELD CROPS, 16%; VEGETABLES, 3%; OTHER FIELD CROPS, 2%;
SEED TREATMENT OF VEGETABLES, 1% (1982-AGRICULTURAL USES ONLY).
(Thousand kg/year): 22.7-68.1 in pastes, principally for wallpaper; 4.5-22.7 in paint for
greenhouses, medical facilities, food-packaging plants, etc; 22.7-68.1 in textiles such as
vinyl-coated fabrics, vinyl car roofs and synthetic turf; < 0.45 in lacquers, in paper and in rubber
stabilizers; and 0.45-4.5 in plasticizers, in polyethylene (used for garbage bags and pond liners), &
in vinyl resins used as precursors of vinyl. Non-agricultural uses
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| Apparent Color | WHITE TO CREAM POWDER ; Yellow amorphous powder ; Colorless crystals
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| Odor | Odorless
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| Melting Point | 178 DEG C
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| Molecular Weight | 300.57
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| Density | 1.74
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| Sensitivity Data | CAPTAN MAY CAUSE SKIN IRRITATION IN SOME WORKERS.
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| Environmental Impact | Captan is a fungicide used to control diseases on fruits, ornamentals, and vegetable crops.
Two companies produce captan in the USA; however, recent production data were not available.
Captan released to soil is not expected to leach extensively, but evaporation from near the surface
of soils may be significant. Since captan readily hydrolyzes in water, it will probably also
hydrolyze in soil depending upon the pH. Captan half-lives in moist soil range from 1 to 12 days.
Captan released to water will have a moderate tendency to sorb to suspended sediments, biota
and sediments, and a low to medium tendency to bioconcentrate (BCF=36-900). Volatilization
may be significant from shallow rivers and streams but will be slower from lakes and ponds. The
primary degradative process for captan in water will be hydrolysis. Hydrolysis half-lives will be on
the order of hours. Information about the importance of biodegradation as a competing process to
hydrolysis were not found. Direct photolysis of captan is not important in relative clear water; in
water with high humic content indirect photooxidation appears to be important. A computer
estimated half-life for captan in the vapor phase of the atmosphere based upon reaction with
hydroxyl radicals is about one hour. Captan may also be present in the atmosphere sorbed to
particulate matter. Captan has been found in food composites at concentrations up to 0.178 ppm.
Average daily intake of captan in the US diet in 1979 was 0.005 mg/kg body wt/day. While the
most widespread captan exposure to the general population probably occurs through
contaminated food and drink, small number of people may be exposed to higher concentrations.
People who mix and apply captan, work in captan storage facilities, treat seeds with captan, or
pick fruit that was treated with captan may receive dermal and inhalation exposure to captan.
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| Environmental Fate | THE DISPOSITION OF (14)C-LABELED CAPTAN WAS EXAMINED AS A
SEED-PROTECTANT COATING IN A TERRESTRIAL MICROCOSM CHAMBER IN
COMPARISON TO A REFERENCE CMPD DIELDRIN. THE TERRESTRIAL MICROCOSM
CHAMBER CONTAINED A SYNTHETIC SOIL MEDIUM, AGRIC CROPS, NUMEROUS
INVERTEBRATES, & A GRAVID GRAY-TAILED VOLE. BY 45 DAYS POSTPLANTING,
TOTAL SOIL RESIDUES (PARENT METABOLITES BOUND RESIDUES) HAD
DECLINED FROM 3 PPM TO 0.26 PPM, WHILE PARENT RESIDUES BECAME
UNDETECTABLE.
TERRESTRIAL FATE: Captan released to soil is not expected to leach extensively(1,2,3).
Evaporation from soil may be significant . Since captan readily hydrolyzes in water(4,5,6), it
will probably also hydrolyze readily in moist soil depending upon the pH. Captan was not
detected at depths of 0-15 cm or 15-30 cm in either of two soil types one week after application
as a drench at rates of 14, 28 and 42 kg ai/ha . In another study, captan half-lives in 3 different
soils under 2 moisture levels (field capacity and submergence) were from 2.83 to 12.23 days(7).
Degradation was faster under submerged conditions than at field capacity(7). Captan distributed
in soil at 125 ppm showed 50% degradation in 1-2 days at room temp(8). Almost 100% of captan
degraded in 1 week when applied to fine sand soil (3.8% organic matter, pH 6.1) at 62.5, 125 and
250 ppm (approx 125, 250, 500 lb/acre)(9). When 10 and 100 mg of captan were added to 1000
g of a loam top soil, captan half-life was 3.5 days in the moist soil (pH 6.4, 17.5% water) and >
50 days in the dry soil (pH 6.2, 1.6% water)(10). These studies indicate that captan will not be
persistent in soil.
AQUATIC FATE: Captan released to water will have a moderate tendency to sorb to suspended
sediments, biota, and sediments (log Kow = 2.35 ). Estimated bioconcentration factor (BCF)
for captan range from 36 to > 910, indicating a low to medium potential for bioconcentration.
Volatilization of captan, based on its estimated Henry's Law constants, may be significant from
shallow rivers and streams but will be slower from lakes and ponds. The primary
degradative process for captan in water will be hydrolysis with the rate being faster at higher
pH's. For example, captan hydrolysis half-life in a river water sample was 170 minutes (2.8 hr) at
pH 7.0 and 28 deg C . Direct photolysis of captan is not important; however, indirect photolysis
may be important . No information was found that clearly indicated the importance of
biodegradation as a competing degradative process compared to hydrolysis. Half-lives for captan
in Lake Superior water were: 7 hr (pH 7.6, 12 deg C), 1 hr (pH 7.6, 25 deg C), 40 hr (pH 6.7, 12
deg C) and 8 hr (pH 6.7, 23 deg C) .
ATMOSPHERIC FATE: Captan may enter the atmosphere sorbed to particulate matter or as a
vapor. A computer-estimated half-life for vapor phase captan reaction with
photochemically generate hydroxyl radical in the atmosphere is 1.09 hr .
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| Drinking Water Impact | DRINKING WATER: Captan has been identified in drinking water but the concentration
and location were not specified .
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