Risks of inhaling or ingesting DHA are not known. People are advised to close their eyes or protect them with goggles and to hold their breath or wear nose plugs while they have a spray-on tanning applied.
Many self tanners use chemical fragrances which may cause skin allergies or may trigger asthma. Furthermore, some of them contain parabens. Parabens are preservatives that can affect the endocrine system.
Tanners can stain clothes. It is therefore important to look for fast drying formulas and wait around 10 to 15 minutes for the product to dry before dressing. 100% Herbal Instant Tan drys instantly in less than 1 minute when rubbed on quickly because it is water based and not oily.
For the 24 hours after self-tanner (containing high DHA levels, ~5%) is applied, the skin is especially susceptible to free-radical damage from sunlight, according to a 2007 study led by Katinka Jung of the Gematria Test Lab in Berlin. Forty minutes after the researchers treated skin samples with high levels of DHA they found that more than 180 percent additional free radicals formed during sun exposure compared with untreated skin. 100% Herbal Instant Tan is different because it does not use DHA, only food based ingredients, no chemicals so there is no connection to free-radical damage from sunlight.