Carbofuran

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Carbofuran
Carbofuran Carbofuran-from-xtal-2D-skeletal.svg
Carbofuran
Carbofuran Carbofuran-from-xtal-3D-balls.png
Carbofuran
Names
Preferred IUPAC name
2,2-Dimethyl-2,3-dihydro-1-benzofuran-7-yl methylcarbamate
Other names
Furadan, Curater, Furacarb
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.014.867 OOjs UI icon edit-ltr-progressive.svg
KEGG
PubChem CID
UNII
  • InChI=1S/C12H15NO3/c1-12(2)7-8-5-4-6-9(10(8)16-12)15-11(14)13-3/h4-6H,7H2,1-3H3,(H,13,14) Yes check.svgY
    Key: DUEPRVBVGDRKAG-UHFFFAOYSA-N Yes check.svgY
  • CNC(=O)Oc1cccc2c1OC(C)C2
Properties
C12H15NO3
Molar mass 221.256 g·mol−1
AppearanceWhite, crystalline solid
Density 1.18 g/cm3
Melting point 151 °C (304 °F; 424 K) [1]
Boiling point 313.3 °C (595.9 °F; 586.5 K)
320 mg/L [2]
Solubility Highly soluble in N-methyl-2-pyrrolidone, dimethylformamide, dimethyl sulfoxide, acetone, acetonitrile, methylene chloride, cyclohexanone, benzene, and xylene [3]
log P 2.32 (octanol/water) [4]
Hazards
Flash point 143.3 °C (289.9 °F; 416.4 K)
Lethal dose or concentration (LD, LC):
8–14 mg/kg (oral, rat)
19 mg/kg (oral, dog)
NIOSH (US health exposure limits):
PEL (Permissible)
none [5]
REL (Recommended)
TWA 0.1 mg/m3 [5]
IDLH (Immediate danger)
N.D. [5]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Carbofuran is a carbamate pesticide, widely used around the world to control insects on 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 there the plant distributes it throughout its organs where insecticidal concentrations are attained. Carbofuran also has contact activity against pests. It is one of the most toxic pesticides still in use.

Contents

It is marketed under the trade names Furadan, by FMC Corporation and Curaterr 10 GR, by Bayer among several others. [6]

Carbofuran exhibits toxicity mediated by the same mechanism as that of the notorious V-series nerve agents and presents a risk to human health. It is classified as an extremely hazardous substance in the United States as defined in Section 302 of the United States Emergency Planning and Community Right-to-Know Act (42 U.S.C. 11002), and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities. [7]

Usage

Carbofuran is used around the world for a wide variety of crops. It is widely used in Asia, Australia, and South America. It is commonly used in Malaysia for vegetables like eggplant (brinjal) where it is a legally registered pesticide. [8] Carbofuran acts through phloem sap against piercing-sucking pests such as green leafhoppers, brown plant hoppers, stem borers and whorl maggots. [9] 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 United States.[ citation needed ]

Chemistry

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. [10] It is manufactured by the reaction of methyl isocyanate with 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran. [11]

Toxicity

Carbofuran has one of the highest acute toxicities to humans of any insecticide widely used on field crops (only aldicarb and parathion are more toxic). 1 ml (1/4 teaspoon) can be fatal to humans.[ citation needed ] Most carbofuran is applied by commercial applicators using closed systems with engineered controls so there is no exposure to it in preparation. However, in developing countries, occupational exposure to carbofuran and resultant carbofuran-serum protein labeling has been reported to impact human health and well-being. [12] Since its toxic effects are due to its activity as a cholinesterase inhibitor it is considered a neurotoxic pesticide.[ citation needed ] A recent study reports that carbofuran is a structural mimic of the neurohormone melatonin and could directly bind to MT2 melatonin receptor (Ki = 1.7 uM). [13] Disruption of melatonin signaling could impact the circadian rhythm balance and is linked to elevated risk of developing diabetes. [14]

Carbofuran is highly toxic to vertebrates with an oral LD50 of 8–14 mg/kg in rats [15] and 19 mg/kg in dogs.

Carbofuran is known to be particularly 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 the granular form was banned by the EPA in 1991, [16] it 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.[ weasel words ]

Carbofuran has been illegally used to intentionally poison wildlife not only in the US, Canada and Great Britain; poisoned wildlife have included coyotes, kites, golden eagles and buzzards. Secondary fatal poisoning of domestic and wild animals has been documented, [17] [18] specifically raptors (bald eagles and golden eagles), domestic dogs, raccoons, vultures and other scavengers. In Kenya, farmers are using carbofuran to kill lions and other predators. [19] [20]

In a number of publicized incidents worldwide, carbofuran has also been used to poison domestic pets. [21] [22] [23]

Illegally smuggled carbofuran is used on 90% of marijuana grown illegally on public land in California. [24] [25] [26] These illegal, carbofuran-contaminated California marijuana grows appear to be the source for the majority of marijuana consumed in states where marijuana hasn't been legalized. [27]

Carbofuran is an endocrine disruptor and a probable reproduction/development intoxicant. [15] At low-level exposures, carbofuran may cause transient alterations in the concentration of hormones. These alterations may consequently lead to serious reproductive problems following repeated exposure. [28] [29] When exposed in utero or during lactation, a decrease in sperm motility and sperm count along with an increase in percent abnormal sperm was observed in rats at 0.4 mg/kg dose level. [30] In one study, the exposure of rats to sublethal amounts of carbofuran decreased testosterone by 88%, while the levels of progesterone, cortisol, and estradiol were significantly increased (1279%, 202%, and 150%, respectively). [29]

Bans

Carbofuran is banned in Canada, Sri Lanka and the European Union. [31]

In 2008, the United States Environmental Protection Agency (EPA) announced that it intended to ban carbofuran. [32] In December of that year, FMC Corp., the sole US manufacturer of carbofuran, announced that it had voluntarily requested that the EPA cancel all but six of the previously allowed uses of that chemical as a pesticide. With this change, carbofuran usage in the United States would be allowed only on corn, potatoes, pumpkins, sunflowers, pine seedlings and spinach grown for seed. [33] However, in May 2009, the EPA canceled all food tolerances, an action which amounts to a de facto ban on its use on all crops grown for human consumption. [34]

Kenya is considering banning carbofuran, [35] but it is legal to buy over-the-counter in Kenya. [19]

Health scare in Thailand

Due to nonregistration of 4 carcinogenic chemicals used on crops not listed in the Dangerous Substances Act of Thailand, vegetables with residues of methomyl, carbofuran, dicrotophos, and EPN were taken off supermarket shelves in July 2012. [36]

Death of lions in Kenya

In 2009, the CBS television news magazine 60 Minutes ran an exposé discussing the use of Furadan by Kenyan farmers as a poison to kill African lions. The piece suggested that Furadan was a serious threat to the future of the lion population in Africa. [20] FMC has commented on this issue through the media and their websites including furadanfacts.com. [37] They engaged with government officials, NGOs and others to try and resolve the illegal use of pesticides to kill wildlife. The company took action to stop the sale of this product and instituted a buyback program in East Africa when it was determined that the illegal and intentional misuse of chemicals against wildlife could not be controlled by education or stewardship programs alone. [38] [39] Despite this, however, National Geographic stated in 2018 that carbofuran "is still very much available" in Kenya. [40]

See also

Related Research Articles

<span class="mw-page-title-main">Pesticide</span> Substance used to destroy pests

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 lampricide. The most common of these are herbicides, which account for approximately 50% of all pesticide use globally. Most pesticides are intended to serve as plant protection products, which in general, protect plants from weeds, fungi, or insects. In general, a pesticide is a chemical or biological agent that deters, incapacitates, kills, or otherwise discourages pests. Target pests can include insects, plant pathogens, weeds, molluscs, birds, mammals, fish, nematodes (roundworms), and microbes that destroy property, cause nuisance, or spread disease, or are disease vectors. Along with these benefits, pesticides also have drawbacks, such as potential toxicity to humans and other species.

Chlordane, or chlordan, is an organochlorine compound that was used as a pesticide. It is a white solid. In the United States, chlordane was used for termite-treatment of approximately 30 million homes until it was banned in 1988. Chlordane was banned 10 years earlier for food crops like corn and citrus, and on lawns and domestic gardens.

<span class="mw-page-title-main">Piperonyl butoxide</span> Chemical compound

Piperonyl butoxide (PBO) is a pale yellow to light brown liquid organic compound used as a synergist component of pesticide formulations. That is, despite having no pesticidal activity of its own, it enhances the potency of certain pesticides such as carbamates, pyrethrins, pyrethroids, and rotenone. It is a semisynthetic derivative of safrole.

<span class="mw-page-title-main">Pyrethrin</span> Class of organic chemical compounds with insecticidal properties

The pyrethrins are a class of organic compounds normally derived from Chrysanthemum cinerariifolium that have potent insecticidal activity by targeting the nervous systems of insects. Pyrethrin naturally occurs in chrysanthemum flowers and is often considered an organic insecticide when it is not combined with piperonyl butoxide or other synthetic adjuvants. Their insecticidal and insect-repellent properties have been known and used for thousands of years.

<span class="mw-page-title-main">Bifenthrin</span> Chemical compound

Bifenthrin is a pyrethroid insecticide. It is widely used against ant infestations.

<span class="mw-page-title-main">Dicofol</span> Chemical compound

Dicofol is an insecticide, an organochlorine that is chemically related to DDT. Dicofol is a miticide that is very effective against spider mite. Its production and use is banned internationally under the Stockholm Convention.

<span class="mw-page-title-main">Chlorfenvinphos</span> Chemical compound

Chlorfenvinphos is the common name of an organophosphorus compound that was widely used as an insecticide and an acaricide. The molecule itself can be described as an enol ester derived from dichloroacetophenone and diethylphosphonic acid. Chlorfenvinphos has been included in many products since its first use in 1963. However, because of its toxic effect as a cholinesterase inhibitor it has been banned in several countries, including the United States and the European Union. Its use in the United States was cancelled in 1991.

<span class="mw-page-title-main">Chlorpyrifos</span> Chemical compound

Chlorpyrifos (CPS), also known as Chlorpyrifos ethyl, is an organophosphate pesticide that has been used on crops, animals, and buildings, and in other settings, to kill several pests, including insects and worms. It acts on the nervous systems of insects by inhibiting the acetylcholinesterase enzyme. Chlorpyrifos was patented in 1966 by Dow Chemical Company.

<span class="mw-page-title-main">Aldicarb</span> Chemical compound (insecticide)

Aldicarb is a carbamate insecticide which is the active substance in the pesticide Temik. It is effective against thrips, aphids, spider mites, lygus, fleahoppers, and leafminers, but is primarily used as a nematicide. Aldicarb is a cholinesterase inhibitor which prevents the breakdown of acetylcholine in the synapse. Aldicarb is considered "extremely hazardous" by the EPA and World Health Organization and has been banned in more than 100 countries. In case of severe poisoning, the victim dies of respiratory failure.

<span class="mw-page-title-main">Fipronil</span> Chemical compound

Fipronil is a broad-spectrum insecticide that belongs to the phenylpyrazole chemical family. Fipronil disrupts the insect central nervous system by blocking the ligand-gated ion channel of the GABAA receptor and glutamate-gated chloride (GluCl) channels. This causes hyperexcitation of contaminated insects' nerves and muscles. Fipronil's specificity towards insects is believed to be due to its greater binding affinity for the GABAA receptors of insects than to those of mammals, and for its action on GluCl channels, which do not exist in mammals. As of 2017, there does not appear to be significant resistance among fleas to fipronil.

<span class="mw-page-title-main">Aldrin</span> Chemical compound

Aldrin is an organochlorine insecticide that was widely used until the 1990s, when it was banned in most countries. Aldrin is a member of the so-called "classic organochlorines" (COC) group of pesticides. COCs enjoyed a very sharp rise in popularity during and after The Second World War. Other noteworthy examples of COCs include DDT. After research showed that organochlorines can be highly toxic to the ecosystem through bioaccumulation, most were banned from use. Before the ban, it was heavily used as a pesticide to treat seed and soil. Aldrin and related "cyclodiene" pesticides became notorious as persistent organic pollutants.

<span class="mw-page-title-main">Endosulfan</span> Chemical compound

Endosulfan is an off-patent organochlorine insecticide and acaricide that is being phased out globally. It became a highly controversial agrichemical due to its acute toxicity, potential for bioaccumulation, and role as an endocrine disruptor. Because of its threats to human health and the environment, a global ban on the manufacture and use of endosulfan was negotiated under the Stockholm Convention in April 2011. The ban has taken effect in mid-2012, with certain uses exempted for five additional years. More than 80 countries, including the European Union, Australia, New Zealand, several West African nations, the United States, Brazil, and Canada had already banned it or announced phase-outs by the time the Stockholm Convention ban was agreed upon. It is still used extensively in India and China despite laws against its use. It is also used in a few other countries. It is produced by the Israeli firm Makhteshim Agan and several manufacturers in India and China. On 13.05.2011, the India Supreme Court ordered a ban on the production and sale of endosulfan in India, pending further notice.

<span class="mw-page-title-main">Endrin</span> Chemical compound

Endrin is an organochlorine compound with the chemical formula C12H8Cl6O that was first produced in 1950 by Shell and Velsicol Chemical Corporation. It was primarily used as an insecticide, as well as a rodenticide and piscicide. It is a colourless, odorless solid, although commercial samples are often off-white. Endrin was manufactured as an emulsifiable solution known commercially as Endrex. The compound became infamous as a persistent organic pollutant and for this reason it is banned in many countries.

<span class="mw-page-title-main">FMC Corporation</span> American manufacturer founded 1883

FMC Corporation is an American chemical manufacturing company headquartered in Philadelphia, Pennsylvania, which originated as an insecticide producer in 1883 and later diversified into other industries. In 1941 at the beginning of US involvement in WWII, the company received a contract to design and build amphibious tracked landing vehicles for the United States Department of War, and afterwards the company continued to diversify its products. FMC employs 7,000 people worldwide, and had gross revenues of US$4.7 billion in 2018.

<span class="mw-page-title-main">Organophosphate poisoning</span> Medical condition

Organophosphate poisoning is poisoning due to organophosphates (OPs). Organophosphates are used as insecticides, medications, and nerve agents. Symptoms include increased saliva and tear production, diarrhea, vomiting, small pupils, sweating, muscle tremors, and confusion. While onset of symptoms is often within minutes to hours, some symptoms can take weeks to appear. Symptoms can last for days to weeks.

<span class="mw-page-title-main">Methomyl</span> Chemical compound

Methomyl is a carbamate insecticide introduced in 1966. It is highly toxic to humans, livestock, pets, and wildlife. The EU and UK imposed a pesticide residue limit of 20 µg/kg for apples and oranges.

<span class="mw-page-title-main">Environmental toxicology</span>

Environmental toxicology is a multidisciplinary field of science concerned with the study of the harmful effects of various chemical, biological and physical agents on living organisms. Ecotoxicology is a subdiscipline of environmental toxicology concerned with studying the harmful effects of toxicants at the population and ecosystem levels.

<span class="mw-page-title-main">Clothianidin</span> Chemical compound

Clothianidin is an insecticide developed by Takeda Chemical Industries and Bayer AG. Similar to thiamethoxam and imidacloprid, it is a neonicotinoid. Neonicotinoids are a class of insecticides that are chemically similar to nicotine, which has been used as a pesticide since the late 1700s. Clothianidin and other neonicotinoids act on the central nervous system of insects as an agonist of nAChR, the same receptor as acetylcholine, the neurotransmitter that stimulates and activating post-synaptic acetylcholine receptors but not inhibiting AChE. Clothianidin and other neonicotinoids were developed to last longer than nicotine, which is more toxic and which breaks down too quickly in the environment.

<span class="mw-page-title-main">Health effects of pesticides</span> Medical condition

Health effects of pesticides may be acute or delayed in those who are exposed. Acute effects can include pesticide poisoning, which may be a medical emergency. Strong evidence exists for other, long-term negative health outcomes from pesticide exposure including birth defects, fetal death, neurodevelopmental disorder, cancer, and neurologic illness including Parkinson's disease. Toxicity of pesticides depend on the type of chemical, route of exposure, dosage, and timing of exposure.

<span class="mw-page-title-main">Thiamethoxam</span> Chemical compound

Thiamethoxam is the ISO common name for a mixture of cis-trans isomers used as a systemic insecticide of the neonicotinoid class. It has a broad spectrum of activity against many types of insects and can be used as a seed dressing.

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