Benomyl

Last updated
Benomyl
Benomyl.png
Names
Preferred IUPAC name
1-(Butylcarbamoyl)-1H-1,3-benzimidazol-2-yl methylcarbamate
Other names
Benomyl
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.037.962 OOjs UI icon edit-ltr-progressive.svg
KEGG
PubChem CID
UNII
  • InChI=1S/C14H18N4O3/c1-3-4-9-15-13(19)18-11-8-6-5-7-10(11)16-12(18)17-14(20)21-2/h5-8H,3-4,9H2,1-2H3,(H,15,19)(H,16,17,20) Yes check.svgY
    Key: RIOXQFHNBCKOKP-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/C14H18N4O3/c1-3-4-9-15-13(19)18-11-8-6-5-7-10(11)16-12(18)17-14(20)21-2/h5-8H,3-4,9H2,1-2H3,(H,15,19)(H,16,17,20)
    Key: RIOXQFHNBCKOKP-UHFFFAOYAA
  • O=C(n1c2ccccc2nc1NC(=O)OC)NCCCC
Properties
C14H18N4O3
Molar mass 290.323 g·mol−1
Appearancewhite crystalline solid [1]
Odor acrid [1]
Melting point 290 °C (554 °F; 563 K) decomposes [1]
0.0004% (20 °C) [1]
Hazards
Flash point noncombustible [1]
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 15 mg/m3 (total) TWA 5 mg/m3 (resp) [1]
REL (Recommended)
none [1]
IDLH (Immediate danger)
N.D. [1]
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 ?)

Benomyl (also marketed as Benlate) is a fungicide introduced in 1968 by DuPont. It is a systemic benzimidazole fungicide that is selectively toxic to microorganisms and invertebrates (especially earthworms), but relatively nontoxic toward mammals. [2]

Contents

Due to the prevalence of resistance of parasitic fungi to benomyl, it and similar pesticides are of diminished effectiveness. Nonetheless, it is widely used.

Toxicity

Benomyl is of low toxicity to mammals. It has an arbitrary LD50 of "greater than 10,000 mg/kg/day for rats". Skin irritation may occur through industrial exposure, and florists, mushroom pickers and floriculturists have reported allergic reactions to benomyl.

In a laboratory study, dogs fed benomyl in their diets for three months developed no major toxic effects, but did show evidence of altered liver function at the highest dose (150 mg/kg). With longer exposure, more severe liver damage occurred, including cirrhosis.

The US Environmental Protection Agency classified benomyl as a possible carcinogen. Carcinogenic studies have produced conflicting results. A two-year experimental study on mice has shown it "probably" causes an increase in liver tumours. The British Ministry of Agriculture Fisheries and Food took the view this was brought about by the hepatotoxic effect of benomyl.

In regards to occupational exposures to benomyl, the Occupational Safety and Health Administration has set a permissible exposure limit of 15 mg/m3 for total exposure over an eight-hour time-weighted average, and 5 mg/m3 for respiratory exposures. [3]

Birth defects

In 1996, a Miami jury awarded US$4 million to a child whose mother was exposed in pregnancy to Benlate. The child was born severe eye defects (clinical anophthalmia). The mother had been exposed to an unusually high dose of this compound through her exposure from a nearby farm, during pregnancy. An important issue in the case was the timing and magnitude of exposure.

In October 2008, DuPont paid confidential settlements to two New Zealand families whose children were born with various birth defects. [4] The mother of one of the children had been exposed to Benlate while working as a Christchurch parks worker before his birth. [5]

Environmental effects

Benomyl binds strongly to soil and does not dissolve in water to any great extent. It has a half-life in turf of three to six months, and in bare soil, a half-life of six months to one year.[ citation needed ]

In 1991, DuPont issued a recall of its Benlate 50DF formula due to suspected contamination with the herbicide atrazine. In the wake of the recall, many US growers blamed Benlate 50DF for destroying millions of dollars' worth of crops. Growers filed over 1,900 damage claims against DuPont, mostly involving ornamental crops in Florida. Subsequent testing by DuPont determined the recalled product was not contaminated with atrazine. The reason for the alleged crop damage is unclear. The Florida Department of Agriculture and Consumer Services suggested Benlate was contaminated with dibutylurea and sulfonylurea herbicides.[ citation needed ]

After several years of legal argument, DuPont paid out about US$750 million in damages and out-of-court settlements. By 1993, a coalition of farm worker and environmental groups came together to form "Benlate Victims Against DuPont", a group which called for a nationwide boycott of DuPont products.

After carrying out tests, DuPont denied Benlate was contaminated with dibutylurea and sulfonylureas and stopped compensation pay-outs. In 1995, a Florida judge rejected a complaint from the Florida Department of Agriculture that had alleged such a link.[ citation needed ]

Cellular biology

Benomyl is used in molecular biology to study the cell cycle in yeast; in fact, the name of the protein class "Bub" (Bub1, etc.) comes from their mutant in which budding was uninhibited by benomyl. Benomyl acts by depolymerizing microtubules. [6] Benomyl is also useful in the laboratory because it is selectively toxic to most members of the Ascomycota, whereas members of the Basidiomycota are largely resistant. [7]

Related Research Articles

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<span class="mw-page-title-main">1,2-Dibromoethane</span> Chemical compound

1,2-Dibromoethane, also known as ethylene dibromide (EDB), is an organobromine compound with the chemical formula C
2
H
4
Br
2
. Although trace amounts occur naturally in the ocean, where it is probably formed by algae and kelp, it is mainly synthetic. It is a dense colorless liquid with a faint, sweet odor, detectable at 10 ppm, and is a widely used and sometimes-controversial fumigant. The combustion of 1,2-dibromoethane produces hydrogen bromide gas that is significantly corrosive.

<span class="mw-page-title-main">Carbofuran</span> Toxic carbamate pesticide

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

Parathion, also called parathion-ethyl or diethyl parathion and locally known as "Folidol", is an organophosphate insecticide and acaricide. It was originally developed by IG Farben in the 1940s. It is highly toxic to non-target organisms, including humans, so its use has been banned or restricted in most countries. The basic structure is shared by parathion methyl.

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

Pentachlorophenol (PCP) is an organochlorine compound used as a pesticide and a disinfectant. First produced in the 1930s, it is marketed under many trade names. It can be found as pure PCP, or as the sodium salt of PCP, the latter of which dissolves easily in water. It can be biodegraded by some bacteria, including Sphingobium chlorophenolicum.

<span class="mw-page-title-main">Persistent organic pollutant</span> Organic compounds that are resistant to environmental degradation

Persistent organic pollutants (POPs) are organic compounds that are resistant to degradation through chemical, biological, and photolytic processes. They are toxic and adversely affect human health and the environment around the world. Because they can be transported by wind and water, most POPs generated in one country can and do affect people and wildlife far from where they are used and released.

<span class="mw-page-title-main">Atrazine</span> Herbicide

Atrazine is a chlorinated herbicide of the triazine class. It is used to prevent pre-emergence broadleaf weeds in crops such as maize (corn), soybean and sugarcane and on turf, such as golf courses and residential lawns. Atrazine's primary manufacturer is Syngenta and it is one of the most widely used herbicides in the United States, Canadian, and Australian agriculture. Its use was banned in the European Union in 2004, when the EU found groundwater levels exceeding the limits set by regulators, and Syngenta could not show that this could be prevented nor that these levels were safe.

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

Toxaphene was an insecticide used primarily for cotton in the southern United States during the late 1960s and the 1970s. Toxaphene is a mixture of over 670 different chemicals and is produced by reacting chlorine gas with camphene. It can be most commonly found as a yellow to amber waxy solid.

<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 World War II. Other noteworthy examples of COCs include dieldrin and 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.

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<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">Methoxychlor</span> Synthetic organochloride insecticide, now obsolete.

Methoxychlor is a synthetic organochloride insecticide, now obsolete. Tradenames for methoxychlor include Chemform, Maralate, Methoxo, Methoxcide, Metox, and Moxie.

<span class="mw-page-title-main">Dichlorvos</span> Insect killing chemical, organophosphate

Dichlorvos is an organophosphate widely used as an insecticide to control household pests, in public health, and protecting stored products from insects. The compound has been commercially available since 1961. It has become controversial because of its prevalence in urban waterways and the fact that its toxicity extends well beyond insects. Since 1988, dichlorvos cannot be used as a plant protection product in the EU.

<i>n</i>-Butylamine Chemical compound

n-Butylamine is an organic compound (specifically, an amine) with the formula CH3(CH2)3NH2. This colourless liquid is one of the four isomeric amines of butane, the others being sec-butylamine, tert-butylamine, and isobutylamine. It is a liquid having the fishy, ammonia-like odor common to amines. The liquid acquires a yellow color upon storage in air. It is soluble in all organic solvents. Its vapours are heavier than air and it produces toxic oxides of nitrogen during combustion.

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

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

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<span class="mw-page-title-main">Pesticides in the United States</span> Review of the topic

Pesticides in the United States are used predominantly by the agricultural sector, but approximately a quarter of them are used in houses, yards, parks, golf courses, and swimming pools.

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

Thiram is the simplest thiuram disulfide and the oxidized dimer of dimethyldithiocarbamate. It is used as a fungicide, ectoparasiticide to prevent fungal diseases in seed and crops and similarly as an animal repellent to protect fruit trees and ornamentals from damage by rabbits, rodents and deer. It is effective against Stem gall of coriander, damping off, smut of millet, neck rot of onion, etc. Thiram has been used in the treatment of human scabies, as a sun screen and as a bactericide applied directly to the skin or incorporated into soap.

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

Demeton, sold as an amber oily liquid with a sulphur like odour under the name Systox, is an organophosphate derivative causing irritability and shortness of breath to individuals repeatedly exposed. It was used as a phosphorothioate insecticide and acaricide and has the chemical formula C8H19O3PS2. Although it was previously used as an insecticide, it is now largely obsolete due to its relatively high toxicity to humans. Demeton consists of two components, demeton-S and demeton-O in a ratio of approximately 2:1 respectively. The chemical structure of demeton is closely related to military nerve agents such as VX and a derivative with one of the ethoxy groups replaced by methyl was investigated by both the US and Soviet chemical-weapons programs under the names V.sub.X and GD-7.

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

Captafol is a fungicide. It is used to control almost all fungal diseases of plants except powdery mildews. It is believed to be a human carcinogen, and production for use as a fungicide in the United States stopped in 1987. Its continued use from existing stocks was allowed, but in 1999 the Environmental Protection Agency banned its use on all crops except onions, potatoes, and tomatoes. In 2006 even these exceptions were disallowed, so currently its use on all crops is banned in the United States. Several other countries have followed suit since 2000, and as of 2010, no countries are known to allow the use of captafol on food crops. Currently, the National Institute for Occupational Safety and Health established a recommended exposure limit of 0.1 mg/m3 for dermal exposures.

References

  1. 1 2 3 4 5 6 7 8 NIOSH Pocket Guide to Chemical Hazards. "#0048". National Institute for Occupational Safety and Health (NIOSH).
  2. Franz Müller; Peter Ackermann; Paul Margot (2012). "Fungicides, Agricultural, 2. Individual Fungicides". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.o12_o06. ISBN   978-3-527-30673-2.
  3. "Benomyl". NIOSH Pocket Guide to Chemical Hazards. Centers for Disease Control and Prevention. April 4, 2011. Retrieved November 19, 2013.
  4. Hill, Ruth (2008-08-18). "Chemical giant pays out for birth defects". The Dominion Post . Fairfax New Zealand Limited. Archived from the original on September 12, 2012. Retrieved 2008-07-18.
  5. "Chemical giant pays out for birth defects".
  6. Hochwagen, A; Wrobel, G; Cartron, M; Demougin, P; Niederhauser-Wiederkehr, C; Boselli, M. G; Primig, M; Amon, A (2005). "Novel Response to Microtubule Perturbation in Meiosis". Molecular and Cellular Biology. 25 (11): 4767–4781. doi:10.1128/MCB.25.11.4767-4781.2005. PMC   1140642 . PMID   15899877.
  7. Malloch, D. (1981). Moulds: their isolation, cultivation and identification . Toronto: Univ. Pr. ISBN   978-0-8020-2418-3.

Further reading