Captan is a general use pesticide (GUP) that belongs to the

phthalimide Phthalimide is the organic compound with the formula C6H4(CO)2NH. It is the imide derivative of phthalic anhydride. It is a Sublimation (phase transition), sublimable white solid that is slightly soluble in water but more so upon addition of ba ...

class of

fungicide Fungicides are biocidal chemical compounds or biological organisms used to kill parasitic fungi or their spores. A fungistatic inhibits their growth. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality, ...

s. It is a white solid, although commercial samples appear yellow or brownish.

Applications

Although it can be applied on its own, Captan is often added as a component of other

pesticide Pesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and lampri ...

mixtures. It is used to control diseases on a number of

fruits In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particula ...

and

vegetables Vegetables are parts of plants that are consumed by humans or other animals as food. The original meaning is still commonly used and is applied to plants collectively to refer to all edible plant matter, including the flowers, fruits, stems, ...

as well as

ornamental plant Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that i ...

s. It also improves the outward appearance of many fruits, making them brighter and healthier-looking. Captan is utilized by both home and agricultural growers and is often applied during apple production. It is also active against certain

oomycetes Oomycota forms a distinct phylogenetic lineage of fungus-like eukaryotic microorganisms, called oomycetes (). They are filamentous and heterotrophic, and can reproduce both sexually and asexually. Sexual reproduction of an oospore is the result ...

, such as

Pythium ''Pythium'' is a genus of parasitic oomycetes. They were formerly classified as fungi. Most species are plant parasites, but ''Pythium insidiosum'' is an important pathogen of animals, causing pythiosis. The feet of the fungus gnat are frequent ...

, making it useful for controlling

damping off Damping off (or damping-off) is a horticultural disease or condition, caused by several different pathogens that kill or weaken seeds or seedlings before or after they germinate. It is most prevalent in wet and cool conditions. Symptoms There ar ...

Biodegradation

The compound biodegrades with halflife of less than 1 day in soil.

Potential health effects

Captan was previously cited as Group B2, a probable human

carcinogen A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive substan ...

by the US

Environmental Protection Agency A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale f ...

(EPA), but was reclassified in 2004. Since the mode of action has been established as a proliferative response (in

mice A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...

only) after

intestinal villi Intestinal villi (singular: villus) are small, finger-like projections that extend into the lumen of the small intestine. Each villus is approximately 0.5–1.6 mm in length (in humans), and has many microvilli projecting from the enterocyte ...

are disrupted, captan has been deemed not likely to cause

tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

s at doses that do not irritate the

intestine The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans ...

. The EPA now states, "The new cancer classification considers captan to be a potential carcinogen at prolonged high doses that cause

cytotoxicity Cytotoxicity is the quality of being toxic to cells. Examples of toxic agents are an immune cell or some types of venom, e.g. from the puff adder (''Bitis arietans'') or brown recluse spider (''Loxosceles reclusa''). Cell physiology Treating cells ...

and regenerative cell

hyperplasia Hyperplasia (from ancient Greek ὑπέρ ''huper'' 'over' + πλάσις ''plasis'' 'formation'), or hypergenesis, is an enlargement of an organ or tissue caused by an increase in the amount of organic tissue that results from cell proliferati ...

. These high doses of captan are many orders of magnitude above those likely to be consumed in the diet, or encountered by individuals in occupational or residential settings. Therefore, captan is not likely to be a human carcinogen nor pose

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

risks of concern when used in accordance with approved product labels. A similar reclassification has been made for

folpet Folpet is the tradename for the organic compound with the formula C6H4(CO)2NSCCl3. It is a fungicide derived from phthalimide (C6H4(CO)2N-) and trichloromethylsulfenyl chloride. The compound is white although commercial samples can appear bro ...

, a structurally related fungicide, which shares a common mechanism of toxicity. A key finding for captan (and

) is these

s are not

mutagenic In genetics, a mutagen is a physical or chemical agent that permanently changes genetic material, usually DNA, in an organism and thus increases the frequency of mutations above the natural background level. As many mutations can cause cancer i ...

in the animal (

in vivo Studies that are ''in vivo'' (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and ...

).Gordon, E. B. 2010b. Captan and Folpet. In: R. Krieger, ed. Hayes Handbook of Pesticide Toxicology pp. 1915-1949. Elsevier, New York

Production

It is the product of the reaction trichloromethylsulfenyl chloride with sodium salt of tetrahydrophthalamide.

References

External links

Captan Technical Fact Sheet - National Pesticide Information CenterCaptan General Fact Sheet - National Pesticide Information Center
* ttps://web.archive.org/web/20061006123222/http://www.epa.gov/oppsrrd1/REDs/factsheets/0120fact.pdf EPA Captan Reregistration Eligibility Decision Factsbr>CDC - NIOSH Pocket Guide to Chemical Hazards - Captan
{{Authority control Fungicides Pesticides Sulfenamides Imides Trichloromethyl compounds