1,3-Dihydroxyacetone, also known as DHA, is a common ingredient in sunless tanning products and cosmetics. It is a colorless sugar that reacts with the amino acids in the outermost layer of the skin to produce a brown color similar to a natural tan.

1,3-Dihydroxyacetone (CAS number 96-26-4):

Chemical Formula: C3H6O3
Molar Mass: 90.08 g/mol
Appearance: 1,3-Dihydroxyacetone is typically a white crystalline solid at room temperature.
Use: It is primarily used in sunless tanning products to give the skin a tan-like appearance without exposure to the sun's UV rays.
Reactivity: DHA reacts with amino acids in the skin to produce pigments called melanoidins, which darken the skin temporarily.
Safety: DHA is generally considered safe for external use on the skin, but inhalation and ingestion should be avoided. It's important to follow product instructions carefully.
Regulation: The use of DHA in cosmetics is regulated by various agencies around the world to ensure its safe use.
DHA is popular as an ingredient in self-tanning lotions, sprays, and creams, providing a safer alternative to tanning in the sun or through UV exposure.