13dihydroxy2propanone

13-dihydroxy-2-propanone, commonly known as dihydroxyacetone (DHA), is a simple three-carbon ketone. Its structure contains a carbonyl group at the second carbon and hydroxyl groups at the first and third carbons, i.e., 1,3-dihydroxy-2-propanone. The molecular formula is C3H6O3 and the molecular weight is 90.08 g/mol. In pure form it is typically a colorless, hygroscopic liquid at room temperature.

DHA occurs as a metabolic intermediate in carbohydrate and glycerol metabolism and can be formed in biological systems from glycerol or through sugar-processing pathways. Industrially, it is produced from glycerol by oxidation, and it can also be generated by fermentation processes using selected microbes.

Among its applications, dihydroxyacetone is best known as a cosmetic self-tanning ingredient. When applied topically, DHA reacts with amino acids in the outer skin layer to form brown pigments, producing a tanned appearance. The coloration develops over several hours and is temporary, fading as skin cells turnover.

Biochemically, DHA can be phosphorylated to dihydroxyacetone phosphate (DHAP) and participates in glycerol and carbohydrate metabolic pathways in some organisms. It is relatively reactive with amine groups, which underlies its tanning reaction on skin and its potential for forming browning products with proteins.

Safety and regulation notes: DHA used in cosmetics is generally regarded as safe at approved concentrations, but it can cause skin or eye irritation in sensitive individuals and should be handled to avoid inhalation of aerosols or ingestion. Standard chemical-handling guidelines apply.