2,4,6,8-Tetramethyl-1,3,5,7-Tetraoxacyclooctane

white fine crystalline powder Metaldehyde is a white crystalline powder with a mild menthol odor.

Metaldehyde (CAS: 108-62-3) is a polymer of acetaldehyde that is used as a pesticide against snails and slugs, and also as a fuel. It was discovered by von Liebig in 1835, and a century later its use as a molluscicide was proposed by Gimingham and Newton in 1937. It is manufactured by reacting acetaldehyde with various acids at a low temperature. As a molluscicide, metaldehyde is used for controlling slugs and snails in gardens of a variety of vegetable and ornamental crops. For this purpose it is available in both solid and liquid formulations with metaldehyde concentrations ranging from 1.8 to 8% in pellet form, or in concentrations of up to 20% in liquid formulations. Some metaldehyde formulations may consist of other pesticides, such as arsenic; while others may contain toxic solvents like ethylene glycol. Therefore, a thorough forensic analysis of the product is recommended to assess complete risk associated with ingestion of these products.Children under the age of 3 years and pets are most commonly poisoned by ingestion of pellets or cakes containing metaldehyde. Intoxication by metaldehyde is typically acute, characterized initially by gastrointestinal and subsequently followed predominantly by neurologic signs. Vomiting, diarrhea, ataxia, tremors, convulsions, and hyperthermia are among the most common toxic signs in children and animals. Other clinical signs in children include mental confusion, muscle cramps and tremors, loss of consciousness, and coma. The proximate neurotoxic mechanisms are not known but reduced levels of neurotransmitters such as serotonin and g-aminobutryric acid (GABA) are implicated. Delayed effects of acute exposure include hepatotoxicity characterized by hepatic necrosis and increased serum liver enzymes. In general, males metabolize metaldehyde twice as fast as females. Therefore, female animals are more sensitive to metaldehyde poisoning compared to males. Most of the neurotoxic signs are seen at dose levels greater than 100 mg of metaldehyde per kilogram. Developmental studies have shown that metaldehyde exposure during pregnancy does not adversely affect fetuses.Chronic metaldehyde exposure is unlikely. However, experimental research has shown that metaldehyde is toxic under chronic exposure conditions. In males, chronic metaldehyde exposure causes testicular atrophy and is also toxic to the prostate gland. It causes atrophy of the prostate gland. It is not clear whether the effects on male gonads are due to endocrine disruption or through a different mechanism. There is also suggestive evidence of carcinogenic potential based on the presence of benign tumors in female rats and mice of both sexes.Provided treatment is initiated early in cases of acute exposure, prognosis is good. In dogs, the mortality rate in a recently completed study was 16%. Because there is no specific antidote, treatment consists of decontamination measures and symptomatic therapy. Recent formulations of metaldehyde pesticides contain denatonium benzoate, a bittering agent. The purpose of adding the bittering agent is to deter excessive ingestion of the products. This, along with new labeling guidelines highlighting the risk to children and pets has caused annual cases to drop significantly since 2006.

white fine crystalline powder

ChEBI: Metaldehyde is a member of the class of tetroxocanes that is 1,3,5,7-tetroxocane which carries four methyl groups at positions 2,4,6 and 8. It is a potent molluscicide and the active ingredient in most slug pellets used for crop protection. It has a role as a molluscicide and a fuel.

Human poison by ingestion. Human systemic effects by ingestion: convulsions or effect on seizure threshold. Moderately toxic by inhalation and skin contact. Experimental reproductive effects. Mutation data reported. A flammable solid. When heated to decomposition it emits acrid smoke and irritating fumes. See also ALDEHYDES.

The product can be prepared by the method of acetylene hydration or acetaldehyde polymerization in the presence of a catalyst.

Molluscicide: A tetramer of acetaldehyde, metaldehyde is a molluscicide used in a variety of vegetable and ornamental crops in the field or greenhouse. It may be formulated with or without calcium arsenate and is also available in a mixed formulation with thiram. A U.S. EPA restricted Use Pesticide (RUP).

There are over 50 pesticides containing metaldehyde registered for use in the United States. It is commonly used as a pesticide against slugs and snails. It is formulated in ready to use liquid, paste, granules, pellets, minipellets, or meal baits. It is also used as a camping fuel. It may be purchased in a tablet form for the latter use.