Chemical Properties
Carbofuran is a broad-spectrum carbamate insecticide and nematicide. It is an odorless,
white crystalline solid. On heating, it breaks down and can release toxic fumes, and irritating or poisonous gases. It is sparingly soluble in water, but very soluble in acetone,
acetonitrile, benzene, and cyclohexone. The liquid formulations of carbofuran are classifi ed as RUPs because of their acute oral and inhalation toxicity to humans. Granular
formulations are also classifi ed as an RUP. In fact, carbofuran was fi rst registered in the
United States in 1969 and classifi ed as an RUP. Exposure to heat breaks down carbofuran,
with the release of toxic fumes. Carbofuran is used for the control of soil-dwelling and
foliar-feeding insects. It is also used for the control of aphids, thrips, and nematodes that
attack vegetables, ornamental plants, crops of sunfl ower, potatoes, peanuts, soybeans,
sugar cane, cotton, rice, and a variety of other crops
Chemical Properties
White Solid
Uses
Cholinesterase inhibitor. Use as systemic insecticide, acaricide, nematocide.
Uses
Systemic insecticide, acaricide, nematocide.
General Description
CARBOFURAN(1563-66-2) is an odorless white crystalline solid. Contact with skin may burn skin and eyes. When exposed to heat or flames CARBOFURAN(1563-66-2) may emit toxic oxides of nitrogen. CARBOFURAN(1563-66-2) is toxic by inhalation, skin contact, and/ or ingestion. CARBOFURAN(1563-66-2) is used as a pesticide.
Reactivity Profile
CARBOFURAN is a carbamate ester. Carbamates are chemically similar to, but more reactive than amides. Like amides they form polymers such as polyurethane resins. Carbamates are incompatible with strong acids and bases, and especially incompatible with strong reducing agents such as hydrides. Flammable gaseous hydrogen is produced by the combination of active metals or nitrides with carbamates. Strongly oxidizing acids, peroxides, and hydroperoxides are incompatible with carbamates. This compound is unstable in an alkaline media. .
Air & Water Reactions
Slightly soluble in water.
Health Hazard
The acute oral LD50 of carbofuran to male and female rats is about 8 mg/kg, while the
acute dermal LD50 for rats is more than 3000 mg/kg. Carbofuran is mildly irritating to
the eyes and skin of rabbits. The acute inhalation toxicity (LC50, 4 h) is 0.075 mg/L for rats.
As with other carbamate compounds, carbofuran’s cholinesterase-inhibiting effect is short
term and reversible.
The symptoms of carbofuran poisoning include, but are not limited to, nausea, vomiting, abdominal cramps, sweating, diarrhea, excessive salivation, weakness, imbalance,
blurring of vision, breathing diffi culty, increased blood pressure, and incontinence.
Death may result at high doses from respiratory system failure associated with carbofuran exposure. Complete recovery from an acute poisoning by carbofuran, with no
long-term health effects, is possible if exposure ceases and the victim has time to regain
his or her normal level of cholinesterase and to recover from symptoms. Reports have
indicated that risks from exposure to carbofuran are especially high among occupational workers and general public suffering with asthma, diabetes, cardiovascular disease, gastrointestinal or urogenital tracts disturbances. The available studies indicate
carbofuran is unlikely to cause reproductive effects in humans at expected exposure
levels. Studies indicate carbofuran is not teratogenic. No signifi cant teratogenic effects
have been found in the offspring of rats given carbofuran (3 mg/kg/day) on days 5 to
19 of gestation
Health Hazard
This material is extremely poisonous. May be fatal if swallowed, inhaled, or absorbed through skin. Contact may burn skin or eyes. Probable lethal oral dose to humans 5 to 50 mg/kg or 7 drops to 1 teaspoon for 150 lb. person.
Potential Exposure
A potential danger to those involved
in the manufacture, formulation, and application of this
insecticide, acaricide, and nematocide.
Fire Hazard
May release nitrogen oxides. Containers may explode in heat of fire. Avoid alkalies. Stable under neutral or acid conditions.
First aid
If this chemical gets into the eyes, remove any
contact lenses at once and irrigate immediately for at least
15 minutes, occasionally lifting upper and lower lids. Seek
medical attention immediately. If this chemical contacts the
skin, remove contaminated clothing and wash immediately
with soap and water. Seek medical attention immediately.
If this chemical has been inhaled, remove from exposure,
begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR if
heart action has stopped. Transfer promptly to a medical
facility. When this chemical has been swallowed, get medical attention. Give large quantities of water and induce
vomiting. Do not make an unconscious person vomit.
Effects may be delayed; keep victim under observation
Shipping
UN2757 Carbamate pesticides, solid, toxic,
Hazard Class: 6.1; Labels: 6.1-Poisonous materials. UN
2811 Toxic solids, organic, n.o.s., Hazard Class: 6.1;
Labels: 6.1-Poisonous materials, Technical Name RequiredUN2811 Toxic solids, organic, n.o.s., Hazard Class: 6.1;
Labels: 6.1-Poisonous materials, Technical Name Required
Incompatibilities
Alkaline substances, acid, strong oxidizers, such as perchlorates, peroxides, chlorates, nitrates,
permanganates.
Waste Disposal
Alkaline hydrolysis is the
recommended mode of disposal. In accordance with
40CFR165, follow recommendations for the disposal of
pesticides and pesticide containers. Must be disposed properly by following package label directions or by contacting
your local or federal environmental control agency, or by
contacting your regional EPA office.
Definition
ChEBI: Carbofuran is a carbamate ester and a member of 1-benzofurans. It has a role as an EC 3.1.1.7 (acetylcholinesterase) inhibitor, a carbamate insecticide, an EC 3.1.1.8 (cholinesterase) inhibitor, an acaricide, an agrochemical, an avicide and a nematicide.
Agricultural Uses
Insecticide, Acaricide, Nematicide: Carbofuran is a broad-spectrum carbamate pesticide that kills insects, mites, and nematodes on contact or after ingestion. It is used against soil and foliar pests of field, fruit, vegetable, and forest crops. Carbofuran, granule form, is banned in the U.S. A U.S. EPA restricted Use Pesticide (RUP). Not approved for use in EU countries. There are 40 global suppliers.. According to the Ecological Incident Investigation System, carbofuran has been responsible for more avian deaths than any other pesticide.
Trade name
A13-27164®; AU'ULTRAMICIN®; BAY 704143®; BAY 78537®; BRIFUR®; CARBODAN®;
CARBOSIP 5G®; CRISFURAN®; CURETERR®; CHINUFUR®; D 1221®; DIAFURAN®; FMC 10242®; FURACARB®; FURADAN®; FURAN®; FURODAN®; KENFURAN®; KENOFURAN®; NEX®; NIA10242; NIAGARA 10242; NIAGARA NIA-10242; PILLARFURAN®; RAMPART®; YALTOX®
Metabolic pathway
The fate of carbofuran has been investigated in soils, plants, mammals,
birds, fish and insects. Metabolic pathways include hydrolysis, oxidation
(ring and N-methyl hydroxylation) and conjugation. The metabolism of
carbofuran has been extensively reviewed by Schlagbauer and Schlagbauer
(1972) and Kuhr and Dorough (1976). Metabolism in economic
animals was reviewed by Akhtar (1985). Consequently the many primary
publications are not usually cited.
Metabolism
Carbofuran (1) is degraded by hydrolysis and oxidation
in soil before ultimate mineralization . The
rate of hydrolysis in soils is slightly higher under flooded
than under nonflooded conditions. Products depend on
the soil type and the prevalence of aerobic or anaerobic
conditions, and it was also reported that carbofuran
did not degrade under anaerobic conditions. The products,
3-hydroxycarbofuran (2) and 3-ketocarbofuran (3), have
been isolated from soil extracts after incubation with carbofuran.
The phenol (7) was identified as a major product
in several studies. The products are further degraded and
bound to soil organic matter. Enhanced degradation may
follow repeated applications of carbofuran to soils, and
bacterial cultures capable of rapidly degrading carbofuran
have been obtained from treated soils.
Degradation
Carbofuran (1) is very stable in weakly acidic media and has a DT50 of
<1 year at pH 4 (22°C). It is stable in neutral media but unstable in
basic conditions (PM). Carbofuran was hydrolysed to the phenol (5) with
a half-life of 67 minutes at 37.5 °C at pH 9.5. 3-Ketocarbofuran (3)
and N-hydroxymethylcarbofuran (4) (Scheme 2) were hydrolysed faster
than carbofuran in alkaline solution (Metcalf et al., 1968). Unlabelled
carbofuran was dissolved in water and irradiated by sunlight in India
for 30 days. Samples were extracted and analysed by GC and TLC.
Products were 3-ketocarbofuran (3) and the 4-hydroxycarbofuran phenol
(8). (Raha and Das, 1990). Solid carbofuran was applied to glass plates
and irradiated with fluorescent light or sunlight. 3-Hydroxycarbofuran
(2) was detected after 2 days; 3-ketocarbofuran (3) was not detected
(Metcalf et al., 1968). These pathways are illustrated in Scheme 1.
Toxicity evaluation
Carbofuran undergoes hydrolytic and oxidative processes
in mammals. In rats, about 72% of the administered
dose was eliminated in the urine within 24 hours
as conjugated metabolites, mainly as conjugates of the 3-
ketocarbofuran phenol (5). The products of metabolism in
plants are 3-hydroxycarbofuran (4) and 3-ketocarbofuran
phenol (5).
