Spray tanning is a form of self tan (or sunless tanning) where a fine mist is sprayed onto the body. This mist has an ingredient in it called Dihydroxyacetone (DHA) and the percentage of DHA determines the colour of the tan. Spray tanning is considered to be the safest tanning option. DHA is also known as gycerone. It is derived  from plant sources such as sugar canes, beets, and sugar, combined with fermentation of glycerine. Primarily used as one of the ingredients in various sunless tanning products. DHA is a TGA approved cosmetic colourant for external application only.