Carbaryl
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Names | |||
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Preferred IUPAC name
Naphthalen-1-yl methylcarbamate | |||
Other names | |||
Identifiers | |||
3D model (
JSmol ) |
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ChEBI | |||
ChEMBL | |||
ChemSpider | |||
ECHA InfoCard
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100.000.505 | ||
EC Number |
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KEGG | |||
PubChem CID
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RTECS number
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UNII | |||
UN number | 2757 | ||
CompTox Dashboard (EPA)
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Properties | |||
C12H11NO2 | |||
Molar mass | 201.225 g·mol−1 | ||
Appearance | Colorless crystalline solid | ||
Density | 1.2 g/cm3 | ||
Melting point | 142 °C (288 °F; 415 K) | ||
Boiling point | decomposes | ||
very low (0.01% at 20°C)[1] | |||
Pharmacology | |||
QP53AE01 (WHO )
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Hazards | |||
GHS labelling: | |||
Danger | |||
H301, H302, H332, H351, H410 | |||
P201, P202, P261, P264, P270, P271, P273, P281, P301+P310, P301+P312, P304+P312, P304+P340, P308+P313, P312, P321, P330, P391, P405, P501 | |||
Flash point | 193-202[1] | ||
Lethal dose or concentration (LD, LC): | |||
LD50 (median dose)
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710 mg/kg (rabbit, oral) 250 mg/kg (guinea pig, oral) 850 mg/kg (rat, oral) 759 mg/kg (dog, oral) 500 mg/kg (rat, oral) 150 mg/kg (cat, oral) 128 mg/kg (mouse, oral) 230 mg/kg (rat, oral)[2] | ||
NIOSH (US health exposure limits): | |||
PEL (Permissible)
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TWA 5 mg/m3[1] | ||
REL (Recommended)
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TWA 5 mg/m3[1] | ||
IDLH (Immediate danger) |
100 mg/m3[1] | ||
Safety data sheet (SDS) | ICSC 0121 | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Carbaryl (1-naphthyl methylcarbamate) is a chemical in the
Production
Carbaryl is often inexpensively produced by direct reaction of
- C10H7OH + CH3NCO → C10H7OC(O)NHCH3
Alternatively, 1-naphthol can be treated with excess
Biochemistry
Carbamate insecticides are slowly reversible inhibitors of the enzyme acetylcholinesterase. They resemble acetylcholine, but the carbamoylated enzyme undergoes the final hydrolysis step very slowly (minutes) compared with the acetylated enzyme generated by acetylcholine (microseconds). They interfere with the cholinergic nervous system and cause death because the effects of the neurotransmitter acetylcholine cannot be terminated by carbamoylated acetylcholinesterase.
Applications
The development of the carbamate insecticides has been called a major breakthrough in pesticides. The carbamates do not have the persistence of chlorinated pesticides. Although toxic to insects, carbaryl is detoxified and eliminated rapidly in vertebrates. It is neither concentrated in fat nor secreted in milk, so is favored for food crops, at least in the US.[6] It is the active ingredient in Carylderm shampoo used to combat head lice until infestation is eliminated.[7]
Ecology
Carbaryl kills both targeted (e.g., malaria-carrying mosquitos) and beneficial insects (e.g.,
Although it can increase survival rates for organisms that benefit from consequential algae blooms, the long term effects of these changes in competition levels and predation can be detrimental to many aquatic ecosystems, particularly those dominated by Anurans.[10]
It is approved for more than 100 crops in the US. Carbaryl is illegal in the EU[11] and Angola.[12]
Safety
Carbaryl is a cholinesterase inhibitor and is toxic to humans. It is classified as a likely human carcinogen by the United States Environmental Protection Agency (EPA.)[13] The oral LD50 is 250 to 850 mg/kg for rats and 100 to 650 mg/kg for mice.[8]
Carbaryl can be produced using methyl isocyanate (MIC) as an intermediary.[5] A leak of MIC used in the production of carbaryl caused the Bhopal disaster, the most lethal industrial accident in history.[14]
References
- ^ a b c d e NIOSH Pocket Guide to Chemical Hazards. "#0100". National Institute for Occupational Safety and Health (NIOSH).
- ^ "Carbaryl". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
- ^ "When Familiar Pesticides Change".
- ^ "When is Sevin not Sevin?". 14 February 2018.
- ^ ISBN 0-8155-1401-8.
- ^ Carbaryl against lice
- ^ a b Carbaryl General Fact Sheet - National Pesticide Information Center
- OCLC 646404494. 5.4.1 Taxon-Wide Impacts — Pesticides and Contaminants, and Their Roles in the Decline of Amphibian Populations. Moore, Robin D.; Claude Gascon. pp. 111-145.
- ISSN 1051-0761.
- ^ "L_2007133EN.01004001.XML".
- ^ Carbaryl Insecticide Hazard Data Archived May 11, 2010, at the Wayback Machine
- ^ Interim Reregistration Eligibility Decision for Carbaryl Archived July 25, 2008, at the Wayback Machine, U.S. EPA, June 2003.
- ISBN 81-7371-515-7.
External links
- Carbaryl Technical Fact Sheet - National Pesticide Information Center
- Carbaryl Pesticide Information Profile - Extension Toxicology Network
- Cholinesterase Inhibition - Extension Toxicology Network
- EPA info
- EPA factsheet
- IPCS (WHO) Health and Safety Guide
- Environmental Health Criteria - WHO
- Exclusive Chemistry Ltd - routes of Sevin synthesis
- CDC - NIOSH Pocket Guide to Chemical Hazards
- Carbaryl in the Pesticide Properties DataBase (PPDB)