Tans continue to be popular, especially with people who naturally have light colored skin. A rich, bronze-colored tan can not only be cosmetically flattering, it can evoke a sun-filled vacation spent at the beach or, in winter, on the ski slopes. But given the fact that exposure to the tanning rays of the sun is accompanied by skin damage and an increased risk of skin cancer, these days many people are opting for "sunless" tans. According to the American Academy of Dermatology, the most effective sunless tanning products contain DHA as the active ingredient. DHA is scientifically known as dihydrixyacetone and is classified as a 3-carbon sugar. When applied to skin, a chemical reaction occurs between amino acids and the outermost skin layer. DHA carries less health risks than any other tanning method, achieving a tan without sun exposure and UV rays. DHA is considered safe enough to be approved for external cosmetic application by the FDA, and is considered nontoxic and noncarcinogenic. DHA should be regarded as offering no SPF protection against UV rays. ALWAYS wear a sunscreen for UV protection. The effects of DHA usually appear within an hour of application. Maximum color results may take anywhere from 8-24 hours to develop. The longevity of this artificial tan usually lasts for 7-10 days but varies with each individual depending on their personal skin renewal cycle. DHA is considered safe for pregnant women. It is suggested that expecting mothers wait until after the first trimester to use any type of self-tanners. During pregnancy some women find that due to increased hormones in their system, the smell is too overbearing and tend to steer clear of these types of products. Due to hypersensitivity it might also be possible that these self-tanners could cause skin irritation. A test should be done in an unnoticeable area 24 hours before applying to the entire body.