Aldehydes and Acetals

More than 300 aldehydes occur in foods, water, and air. Due to the electrophilicity of the carbonyl carbon, particularly when proximal to a carbon–carbon double bond, aldehydes react with thiols and amines to form protein–protein, DNA–protein, and DNA–DNA cross-links. Despite their potential for causing cell damage, toxicological and exposure data for a large number of aldehydes are lacking. Inhalation and ingestion studies have demonstrated that a number of aldehydes are irritants and can induce tumors in animal models. Formaldehyde, which is a suspected carcinogen, is the most widely studied of these compounds. The physicochemical properties of saturated aldehydes are summarized. Toxicological and health effects are given. Keywords: acetals; aliphatic dialdehydes; aromatic aldehydes; Clean Air Act; EPA; flavoring agents; formaldehyde; halogenated aldehydes; heterocyclic aldehydes; saturated aliphatic aldehydes; unsaturated aliphatic aldehydes; urea–formaldehyde resins