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The information in this profile may be out-of-date.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

Aldicarb

Trade and Other Names: Aldicarb is also called aldicarbe. Trade names include Temik, ENT 27093, OMS 771, and UC 21149.

Regulatory Status: Aldicarb is a Restricted Use Pesticide (RUP) in the U.S. RUPs may be purchased and used only by certified applicators. Aldicarb is rated toxicity class I - highly toxic. Products containing aldicarb bear the signal word DANGER-POISON on the label.

Chemical Class: carbamate

Introduction: Aldicarb, a member of the carbamate class of chemicals, is an extremely toxic systemic insecticide. Used to control mites, nematodes, and aphids, it is applied directly to the soil. It is used widely on cotton, peanut, and soybean crops. In the mid-1980s, there were highly publicized incidents in which misapplication of aldicarb contaminated cucumbers and watermelons and led to adverse effects in people. In 1990, the manufacturer of Temik (aldicarb), announced a voluntary halt on its sale for use on potatoes because of concerns about groundwater contamination.

Formulation: It is formulated as a granular mix (10 to 15% active ingredient) because of its toxicity. It is not compatible with alkaline materials and is noncorrosive to metals and plastics.

Toxicological Effects:

• Acute toxicity: The primary route of human exposure to aldicarb is consumption of contaminated food and of water from contaminated wells [14]. Occupational exposure to high levels of aldicarb is due to product handling and most cases of aldicarb poisoning occur from loading and application of the pesticide. Atypical of carbamates in general, aldicarb is extremely toxic through both the oral and dermal routes [5]. Absorption from the gut is rapid and almost complete. When administered in oil or other organic solvents aldicarb is absorbed rapidly through the skin. Its skin toxicity is roughly 1000 times that of other carbamates [5]. In humans, the onset of symptoms is rapid, 15 minutes to 3 hours. Symptoms disappear in 4 to 12 hours [15]. Aldicarb's LD50 in rats, mice, guinea pigs, and rabbits ranges from 0.5 mg/kg to 1.5 mg/kg when administered in a liquid or oil form. The toxicities of the dry granules are distinctly lower (LD50 = 7.0 mg/kg), though still highly toxic [5,15]. Aldicarb is a cholinesterase inhibitor and so can result in a variety of symptoms including weakness, blurred vision, headache, nausea, tearing, sweating, and tremors. Very high doses can result in death due to paralysis of the respiratory system.
• Chronic toxicity: There is very little evidence of chronic effects from aldicarb exposure. Rats and dogs fed low doses of aldicarb for two years showed no significant adverse effects [15]. One epidemiological study suggested a possible link between low-level exposure and immunological abnormalities [15]. The results of this study have been widely disputed.
• Reproductive effects: Aldicarb administered to pregnant rats at very low levels (0.001 to 0.1 mg/kg/day) depressed acetylcholinesterase activity more in the fetuses than in the mother. The aldicarb was also retained in the mother's body for longer periods than in nonpregnant rats [16]. A three-generation study at doses of 0.05 and 0.10 mg/kg/day produced no significant toxic effects and in another study, a dose of 0.70 mg/kg/day produced no adverse effects [5]. Thus, reproductive effects in humans are unlikely at expected exposure levels.
• Teratogenic effects: No teratogenic effects have been found in rats exposed to aldicarb [5].
• Mutagenic effects: Studies show that aldicarb is not mutagenic [15].
• Carcinogenic effects: Studies indicate that aldicarb is not carcinogenic [15].
• Organ toxicity: Aldicarb's effects are seen primarily on the nervous system.
• Fate in humans and animals: Aldicarb is metabolized and quickly excreted. Rats and cows eliminate 80 to 90% of a dose of aldicarb within 24 hours. Elimination is mainly through urine, but some aldicarb leaves by way of the lungs in expired air and some through milk in cows [5].

Ecological Effects:

• Effects on birds: Aldicarb is very highly toxic to birds. The greatest exposure to the organisms is through the ingestion of unincorporated granules and contaminated earthworms [17]. The LD50s of the compound range from 1.78 mg/kg in the red-winged blackbird to 5.34 mg/kg in the ring-necked pheasant.
• Effects on aquatic organisms: Aldicarb is moderately toxic to fish. The LC50 (96-hour) is 8.8 mg/L in rainbow trout and 1.5 mg/L in bluegill sunfish [10]. Bioconcentration in aquatic species is low [14,17,18].
• Effects on other organisms: Aldicarb is not toxic to bees, even when applied directly [10].

Environmental Fate:

• Breakdown in soil and groundwater: Aldicarb is moderately persistent in soil [10]. Moisture and pH have important impacts on the rate of breakdown. Aldicarb is very soluble and mobile in soil [8]. Aldicarb movement is most serious for sandy or sandy loam soils. It has been found in wells in over 25 countries and in 12 states at concentrations above the drinking water Maximum Contaminant Level [14].
• Breakdown in water: The half-life of aldicarb in water is from 1 day to a few months [14]. In pond water, aldicarb is broken down rapidly and has a half-life of 5 to 10 days. It is degraded by bacteria, sunlight, and reactions with water. Because of its rapid degradation rate, levels in surface water may be lower than those in groundwater [5].
• Breakdown in vegetation: In plants, aldicarb is rapidly converted to sulfoxide and more slowly to the sulfone compound. Citrus trees treated with 18 g per tree had the highest residue levels in the leaves [8]. Residues of aldicarb also have been reported in sugar beets and grape leaves and fruit [14]. In 1991, the manufacturer called for a halt to aldicarb use on bananas because of the elevated levels of residue found.

Physical Properties:

• Appearance: Aldicarb is a white crystalline solid. It is formulated as a granular mix (10 to 15% active ingredient) because of its toxicity. It is not compatible with alkaline materials and is noncorrosive to metals and plastics.
• Chemical Name: 2-methyl-2-(methylthio)propionaldehyde O-methylcarbamoyloxime [10]
• CAS Number: 116-06-3
• Molecular Weight: 190.27
• Water Solubility: 6000 mg/L @ room temperature [10]
• Solubility in Other Solvents: s. in acetone, xylene, ethyl ether, toluene, and other organic solvents [10]
• Melting Point: 99-100 C [10]
• Vapor Pressure: 13 mPa @ 20 C [10]
• Partition Coefficient: 0.0531[8]
• Adsorption Coefficient: 30 [13]

Exposure Guidelines:

• ADI: 0.003 mg/kg/day [10]
• MCL: 0.003 m/L [19]
• RfD: 0.001 mg/kg/day [20]
• PEL: Not Available
• HA: Not Available
• TLV: Not Available

Basic Manufacturer:

Rhone-Poulenc Ag. Co.
P.O. Box 12014
2 T.W. Alexander Park, NC 27709

• Phone: 919-549-2000
• Emergency: 800-334-7577

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.