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The information in this profile may be out-of-date.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

Cacodylic acid

Trade and Other Names: Cacodylic acid is also known as dimethylarsinic acid. Trade names include Ansar 138, Arsan, Bolls-Eye, Broadside, Check-Mate, Cotton Aide HC, Dilic, Moncide, Montar, Phytar, Phytar 138, Phytar 600, Rad-E-Cate 25, Silvisar 510, and Sylvicor.

Regulatory Status: Cacodylic acid is a General Use Pesticide (GUP). Products containing cacodylic acid are categorized toxicity class III - slightly toxic and bear the Signal Word CAUTION.

Chemical Class: arsenical

Introduction: Cacodylic acid is an arsenical nonselective contact herbicide which defoliates or desiccates a wide variety of plant species. It is used as a cotton defoliant, for lawn renovation, for weed control in non-crop areas such as around buildings, near perennial ornamentals, along fence rows, and in forest management. Its phytotoxic properties are quickly inactivated upon contact with the soil. It is available in concentrated solution formulations.

Formulation: It is available in concentrated solution formulations.

Toxicological Effects:

• Acute toxicity: Cacodylic acid is slightly toxic by inhalation and by ingestion. It is absorbed into the bloodstream more readily through inhalation than through ingestion or dermal exposure [8]. Arsenate, formed from the breakdown of cacodylic acid, slows the production of energy in cells. The symptoms of poisoning with arsenicals such as cacodylic acid include a salty taste, burning in the throat, colicky pains in the stomach and intestines, and garlicky odor of the breath, urine, and sweat. In persons exposed to sufficient arsenical dust, the onset of illness is usually characterized by difficult or short breath with pain in the chest, followed by nausea and diarrhea. Severe arsenic poisoning causes headache, dizziness, vomiting, profuse and watery diarrhea, followed by dehydration, electrolyte imbalance, gradual fall in blood pressure, stupor, convulsions, general paralysis, and possible death within 3 to 14 days [58]. Cacodylic acid is irritating to skin or eyes [58]. Product formulations may be irritating, depending on their acidity or alkalinity. Blistering or conjunctivitis may occur [8]. The oral LD50 for cacodylic acid in rats is 644 to 830 mg/kg [1,58]. The inhalation LC50 for cacodylic acid in rats is 3.9 mg/L [58].
• Chronic toxicity: Blanching or flushing of the skin (especially of the fingers), cirrhosis of the liver, atrophy of the bone marrow, kidney damage, and loss of sensory and motor functions have been reported. About 6 weeks after exposure to cacodylic acid, white bands may appear across the toe and finger nails [30,58]. Signs of chronic arsenate exposure include loss of appetite, weight loss, weakness, nausea, alternating diarrhea and constipation, colic, pain and tenderness in the limbs (usually starting in the fingers or toes), dermatitis, abnormal changes in skin color, loss of hair, giddiness, and headache. Prolonged exposure may cause gradual mental and physical deterioration. There may be disturbances of sight, taste, smell, and bladder function [8]. Prolonged or repeated exposure of the skin to arsenicals may cause dermatitis. Prolonged eye contact may cause conjunctivitis and has caused eruptions of eyelids, conjunctiva, and even the cornea. Repeated exposure to low levels of arsenic may produce increased tolerance for arsenic [8].
• Reproductive effects: Large dietary doses of cacodylic acid for extended periods of time decrease fertility. Male rats fed 226 mg/kg/day for 3 weeks showed reduced sperm production [58]. Such effects are unlikely in humans at expected exposure levels.
• Teratogenic effects: Oral doses 0.35 mg/kg/day to pregnant rats produced smaller fetus size and decreased body weight. In rabbits, doses of 48 mg/kg/day decreased food intake and body weight in the offspring [58]. Cacodylic acid is unlikely to cause teratogenic effects in humans at expected exposure levels.
• Mutagenic effects: Cacodylic acid did not show mutagenicity in a variety of gene and chromosome assays on bacterial and mammalian cells [58].
• Carcinogenic effects: No data are currently available.
• Organ toxicity: Cacodylic acid affects a variety of organ systems. The kidney, liver, heart, digestive tract, and central and peripheral nervous systems are all targets [8,58].
• Fate in humans and animals: Cacodylic acid is readily absorbed into the bloodstream when ingested. It is broken down in the liver. It accumulates in the skin, finger and toe nails, and hair, which also serve as means of excretion [8].

Ecological Effects:

• Effects on birds: No data are currently available.
• Effects on aquatic organisms: Cacodylic acid presents a low toxicity hazard to most fish. The LC50 for cacodylic acid in bluegill sunfish is 1000 mg/L [1].
• Effects on other organisms: Cacodylic acid is not toxic to bees with LD50 values reported in the 100 to 1000 ppm range [1].

Environmental Fate:

• Breakdown in soil and groundwater: Cacodylic acid has low to moderate persistence in soil. Cacodylic acid is quickly inactivated upon contact with the soil by adsorption to soil particles and ion exchange [8,58]. Soil microorganisms degrade most of the cacodylic acid in the soil [58]. A breakdown product, arsenic, competes with phosphorus in the soil. It forms insoluble salts with chromium, silver, or other metals [8].
• Breakdown in water: No data are currently available.
• Breakdown in vegetation: Arsenic, from the metabolism of cacodylic acid, poisons cell division in plants [8].

Physical Properties:

• Appearance: Cacodylic acid is a colorless crystalline solid with an offensive odor [1].
• Chemical Name: dimethylarsinic acid [1]
• CAS Number: 75-60-5
• Molecular Weight: 138.00
• Water Solubility: 2000 mg/L @ 25 C [1]
• Solubility in Other Solvents: diethyl ether, i.s.; alcohol, s.s.; ethanol, s.; acetic acid, s.
• Melting Point: 192-198 C [1]
• Vapor Pressure: Not Available
• Partition Coefficient: Not Available
• Adsorption Coefficient: 1000 (estimated) [8]

Exposure Guidelines:

• ADI: Not Available
• MCL: Not Available
• RfD: 0.003 mg/kg/day [13]
• PEL: Not Available
• HA: Not Available
• TLV: Not Available

Basic Manufacturer:

Drexel Chemical Company
1700 Channel Avenue
Memphis, TN 38113

• Phone: 901-774-4370
• Emergency: Not Available
  

References:

References for the information in this PIP can be found in Reference List Number 10

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.