Metaldehyde exists as a mixture of four stereoisomers, molecules that differ with respect to the relative orientation of the methyl groups on the 8-membered ring.

[5] Metaldehyde is effective on pests by contact or ingestion and works by limiting the production of mucus in mollusks making them susceptible to dehydration.

[6] Metaldehyde products were used to control the invasive African land snail population in Miami-Dade County in Florida.

On 19 December 2018, the British government banned the use of metaldehyde slug pellets outdoors from spring 2020; after this date it would only be legal to use it in permanent greenhouses.

[13] A diagnosis can be made by an analysis of stomach contents, which tend to have an apple cider vinegar odor, as well as a history of exposure to the chemical.

Treatment includes IV fluids, sedation, lowering body temperature, and purging of stomach contents with charcoal.

[14] The metaldehyde tablets resemble candies and do not taste bad, making accidental ingestion possible by children or even by adults unaware of their true nature.

Oral ingestions of metaldehyde have been described in adults attempting suicide; amongst them, the majority experienced gastrointestinal or neurological symptoms.