Carbofuran
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| Carbofuran | |
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| IUPAC name | 2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate |
| Other names | Carbofuran, Furadan, Curater |
| Molecular formula | C12H15NO3 |
| Molar mass | 221.25 |
| CAS number | [1563-66-2] |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Carbofuran is one of the most toxic carbamate pesticides. It is marketed under the trade names Furadan, by FMC Corporation and Curater, among several others. It is used to control insects in a wide variety of field crops, including potatoes, corn and soybeans. It is a systemic insecticide, which means that the plant absorbs it through the roots, and from here the plant distributes it throughout its organs (mainly vessels, stems and leaves; not the fruits), where insecticidal concentrations are attained. Carbofuran also has contact activity against pests.
It has one of the highest acute toxicities to humans of any insecticide widely used on field crops (more toxic are only aldicarb and parathion). A quarter teaspoon ( 1 mL) can be fatal. Most carbofuran is applied by commercial applicators using closed systems with engineered controls, so that there is no exposure to the chemical through pouring or measuring. Toxic effects are due to its activity as a cholinesterase inhibitor (it is thus considered a neurotoxic pesticide).
Carbofuran is also known to be highly toxic to birds. In its granular form, a single grain will kill a bird. Birds often eat numerous grains of the pesticide, mistaking them for seeds, and then die shortly thereafter. Before it was banned by USEPA in 1991 ([1]), granular carbofuran was blamed for millions of bird deaths per year. The liquid version of the pesticide is less hazardous to birds since they are not as likely to ingest it directly, but it is still very hazardous.
Carbofuran usage has increased in recent years because it is one of the few insecticides effective on soybean aphids, which have expanded their range since 2002 to include most soybean-growing regions of the U.S.
The technical or chemical name of carbofuran is 2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate and its CAS number is 1563-66-2 and it is manufactured by reaction of methyl isocyanate with 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran.
Oral LD50: Rats 8–14 mg/kg, Dogs 19 mg/kg.
[edit] Wildlife Toxicity
At least one report suggests that carbofuran has been illegally used to intentionally poison coyotes and other wildlife in Western Canada. Secondary fatal poisoning of raptors, specifically bald eagles and golden eagles, has been suggested. (See Wobeser et al. 2004. Secondary poisoning of eagles following intentional poisoning of coyotes with anticholinesterase pesticides in Western Canada. Journal of Wildlife Diseases 40(2):163-172).
See also: Dutch standards.
