Tanning sprays contain a color additive called dihydroxyacetone, also referred to as
DHA (but not to be confused with the healthy omega-3 fat
DHA). Sunless tanning products may contain anywhere between 1 to 15 percent DHA; the higher the DHA level, the darker the tan produced.
Manufacturers of sunless tan products claim that DHA is a simple carbohydrate sugar solution but a toxicologist who investigated the harmful effects of tanning beds disagrees.