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The information in this profile may be out-of-date. It was last revised in 1996. EXTOXNET no longer updates this information, but it may be useful as a reference or resource.

Please visit the National Pesticide Information Center (NPIC) to find updated pesticide fact sheets. If you don't find a fact sheet related to your question, feel free to call 1-800-858-7378. NPIC is open five days a week from 8:00am to 12:00pm Pacific Time.

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E X T O X N E T

Extension Toxicology Network

Pesticide Information Profiles

A Pesticide Information Project of Cooperative Extension Offices of Cornell University, Oregon State University, the University of Idaho, and the University of California at Davis and the Institute for Environmental Toxicology, Michigan State University. Major support and funding was provided by the USDA/Extension Service/National Agricultural Pesticide Impact Assessment Program.

EXTOXNET primary files maintained and archived at Oregon State University

Revised June 1996

Carbofuran

Trade and Other Names: Trade names include Furadan, Bay 70143, Carbodan, Carbosip, Chinofur, Curaterr, D 1221, ENT 27164, Furacarb, Kenafuran, Pillarfuron, Rampart, Nex, and Yaltox.

Regulatory Status: Following a Special Review, the EPA initiated a ban on all granular formulations of carbofuran which became effective on September 1, 1994. Before 1991, 80% of the total usage of carbofuran was in granular formulations. The ban was established to protect birds and is not related to human health concerns. Bird kills have occurred when birds ingested carbofuran granules, which resemble grain seeds and when predatory or scavenging birds have ingested small birds or mammals which had eaten carbofuran pellets. There is no ban on liquid formulations of carbofuran. Liquid formulations of carbofuran are classified as Restricted Use Pesticides (RUP) because of their acute oral and inhalation toxicity to humans. Granular formulations are also classified as RUP's, but for a different reason; their toxicity to birds. Liquid formulations bear the Signal Word WARNING. Granular formulations bear the Signal Word DANGER. Formulations of carbofuran are in toxicity class I - highly toxic or toxicity class II - moderately toxic.

Chemical Class: carbamate

Introduction: 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 is available in liquid and granular formulations, but as stated avove the granule form is banned in the U.S.

Formulation: Carbofuran is available in liquid and granular formulations, but as stated above, the granular form is banned in the U.S.

Toxicological Effects:

• Acute toxicity: Carbofuran is highly toxic by inhalation and ingestion and moderately toxic by dermal absorption [5]. As with other carbamate compounds, carbofuran's cholinesterase-inhibiting effect is short-term and reversible [5]. Symptoms of carbofuran poisoning include: nausea, vomiting, abdominal cramps, sweating, diarrhea, excessive salivation, weakness, imbalance, blurring of vision, breathing difficulty, increased blood pressure, and incontinence. Death may result at high doses from respiratory system failure associated with carbofuran exposure [5]. 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 their normal level of cholinesterase and to recover from symptoms [5]. The oral LD50 is 5 to 13 mg/kg in rats, 2 mg/kg in mice, and 19 mg/kg in dogs. The dermal LD50 is >1000 mg/kg in rabbits, [5]. The LC50 (4-hour) for inhalation of carbofuran is 0.043 to 0.053 mg/L in guinea pigs [10].
• Chronic toxicity: Rats given very high doses (5 mg/kg/day) for two years showed decreases in weight. Similar tests with mice gave the same results [5]. Prolonged or repeated exposure to carbofuran may cause the same effects as an acute exposure [5].
• Reproductive effects: Consuming high doses over long periods of time caused damage to testes in dogs, but carbofuran did not have any reproductive effects on rats or mice [5]. Available studies indicate carbofuran is unlikely to cause reproductive effects in humans at expected exposure levels.
• Teratogenic effects: Studies indicate carbofuran is not teratogenic. No significant teratogenic effects have been found in offspring of rats given carbofuran (3 mg/kg/day) on days 5 to 19 of gestation. No effects were found in offspring of mice given as much as 1 mg/kg/day throughout gestation. In rabbits, up to 1 mg/kg/day on days 6 to 18 of gestation was not teratogenic [5].
• Mutagenic effects: Weak or no mutagenic effects have been reported in animals and bacteria. Carbofuran is most likely nonmutagenic [5].
• Carcinogenic effects: Data from animal studies indicate that carbofuran does not pose a risk of cancer to humans [5].
• Organ toxicity: Carbofuran causes cholinesterase inhibition in both humans and animals, affecting nervous system function.
• Fate in humans and animals: Carbofuran is poorly absorbed through the skin [32]. It is metabolized in the liver and eventually excreted in the urine. The half-life in the body is from 6 to 12 hours. Less than 1% of a dose will be excreted in a mother's milk. It does not accumulate in tissue [5].

Ecological Effects:

• Effects on birds: Carbofuran is highly toxic to birds. One granule is sufficient to kill a small bird. Bird kills have occurred when birds ingested carbofuran granules, which resemble grain seeds in size and shape, or when predatory or scavenging birds have ingested small birds or mammals that have eaten carbofuran pellets [33]. Red-shouldered hawks have been poisoned after eating prey from carbofuran-treated fields [17]. The LD50 is 0.238 mg/kg in fulvous ducks, 0.48 to 0.51 mg/kg in mallard ducks, 12 mg/kg in bobwhite quail, and 4.15 mg/kg in pheasant [17]. The LD50 is 25 to 39 mg/kg in chickens consuming carbofuran as a powder [10]. The LC50 (96-hour) in Japanese quail is 746 ppm [34].
• Effects on aquatic organisms: Carbofuran is highly toxic to many fish. The LD50 (96-hour) is 0.38 mg/L in rainbow trout and 0.24 mg/L in bluegill sunfish [10]. The compound has a low potential to accumulate in aquatic organisms. The bioconcentration factor ranges from 10 in snails to over 100 in fish [14].
• Effects on other organisms: CArbofuran is toxic to bees except in the granular formulation [10].

Environmental Fate:

• Breakdown in soil and groundwater: Carbofuran is soluble in water and is moderately persistent in soil. Its half-life is 30 to 120 days. In soil, carbofuran is degraded by chemical hydrolysis and microbial processes. Hydrolysis occurs more rapidly in alkaline soils [14]. Carbofuran breaks down in sunlight. Carbofuran has a high potential for groundwater contamination [14]. Carbofuran is mobile to very mobile in sandy loam, silty clay, and silty loam soils; moderately mobile in silty clay loam soils; and only slightly mobile in muck soils. Small amounts of carbofuran have been detected (1 to 5 ppb) in water table aquifers beneath sandy soils in New York and Wisconsin [14].
• Breakdown in water: In water, carbofuran is subject to degradation by chemical hydrolysis under alkaline conditions. Photodegradation and aquatic microbes may also contribute to degradation. The hydrolysis half-lives of carbofuran in water at 25 C are 690, 8.2, and 1.0 weeks at pH values of 6.0, 7.0, and 8.0, respectively. Carbofuran does not volatilize from water, nor does it adsorb to sediment or suspended particles [14].
• Breakdown in vegetation: The half-life of carbofuran on crops is about 4 days when applied to roots, and longer than 4 days if applied to the leaves [8].

Physical Properties:

• Appearance: Carbofuran is an odorless, white crystalline solid. Heat breakdown can release toxic fumes. Fires, and the runoff from fire control, may produce irritating or poisonous gases. Closed spaces (storage, etc.) should be aired before entering.
• Chemical Name: 2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate [10]
• CAS Number: 1563-66-2
• Molecular Weight: 221.25
• Water Solubility: 320 mg/L @ 25 C [10]
• Solubility in Other Solvents: acetone v.s.; acetonitrile v.s.; benzene v.s.; cyclohexone v.s. (5)
• Melting Point: 153-154 C [10]
• Vapor Pressure: 2.7 mPa @ 33 C [10]
• Partition Coefficient: 1.2304-1.4150 [10]
• Adsorption Coefficient: 22 [13]

Exposure Guidelines:

• ADI: 0.01 mg/kg/day [10]
• MCL: 0.04 mg/L [19]
• RfD: 0.005 mg/kg/day [20]
• PEL: Not Available
• HA: Not Available
• TLV: 0.1 mg/m3 (8-hour) [31]

Basic Manufacturer:

FMC Corporation
Agricultural Chemicals Group
1735 Market Street
Philadelphia, PA 19103

• Phone: 215-299-6661
• Emergency: 800-331-3148
  

References:

References for the information in this PIP can be found in Reference List Number 3

DISCLAIMER: The information in this profile does not in any way replace or supersede the information on the pesticide product labeling or other regulatory requirements. Please refer to the pesticide product labeling.