Dihydoxyacetone and its role in sunless tanning
This page is intended to educate those who have had little or no experience with DHA-based products. We have gathered the most important information for tanners, customers and technicians about the sunless ingredient DHA. How it works, formulations, application safety and precautions are all highlighted to make sure the best possible results come from the tanning products being used.
How DHA Works
DHA is scientifically known as dihydoxyacetone and is classified as a 3-carbon sugar. When applied to skin, a chemical reaction occurs between amino acids and the outermost skin layer, the strateum corneum, to produce a brown color, or tan. 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 non-carcinogenic. DHA should be regarded as offering no SPF protection against UV rays, although a small protective effect has been observed. Always wear a sunscreen for UV protection.
Results and Effectiveness
The effects of DHA usually appears within and hour of application of the spray tan solution. Maximum color results may take anywhere from 5-24 hours to develop, depending on the solution ingredients and the amount of DHA included. The longevity of this artificial tan usually lasts for 5-7 days but varies with each individual depending on their personal skin renewal cycle.
DHA Solution Formulation
There are multiple self-tanning preparations containing DHA on the market and many will claim to be the "best formulation available". The truth is, all these self-tanning solutions rely on the same basic ingredients to produce a sunless tan, the main effective ingredient being DHA. Concentrations of DHA in these formulas can range from 5% to 18%. A lighter-shade product containing a lower DHA concentration is recommended for new users and technicians as it is more forgiving of uneven application, naturally light skin tones or rough surfaces. Some formulations also contain moisturizers for those with naturally dry skin. Other formulations are alcohol-based and are more suitable for users with naturally oily skin. Other ingredients may be incorporated into a solution formulation for different marketable reasons such as to facilitate application, make the color last longer or to reduce the time needed for results.
Care and Handling of DHA Solutions
DHA is temperature-sensitive and will degrade in warmer temperatures. Always consult the handling and storage directions for your particular solution as some brands prepare their formulas to increase their stability at higher temperatures. As a general rule of thumb, store your DHA solution between 60-70 degrees. Refrigeration should not be harmful to any of the solution ingredients, this can be a good way to ensure a cooler storage. Air exposure can also cause the DHA to break down rapidly, make sure to store any leftover solution from a spray session in an air-tight container.
The Food and Drug Administration lists DHA as a color additive for use in "coloring" the human body. The Food, Drug and Cosmetic Act authorizes the regulation of color additives and restricts the use of DHA strictly to external application. This authorization specifically excludes the lips and any body surface covered by a mucous membrane and excludes DHA from internal use. The FDCA regulations also declare no color additive may be used in cosmetics intended for use in the eye, unless specifically permitted (DHA is not). Obviously, applying DHA as a spray or a mist may present some challenges in complying with these FDA ordinances and special care should be taken to inform the client to avoid breathing in the sunless product during the application process. Proper ventilation for staff and clients should be a top priority for air quality in the spray tanning area or room. Consumers should also do what they can to avoid direct application of products into the eye area, and use barrier products to avoid solution coming into contact with mucous membranes. We have a great selection of these barrier-type products, including lip balm and eye protection, on our Tanning Supplies Page.
Achieving the Best Results
The final result of a DHA sunless tan will depend on the solution formulation, the technician's or consumer's application technique and the tanner's complexion type. There are application techniques and common practices that are highly recommended for both the technician and the client to achieve the maximum color desired for a tan. The client should begin preparation by washing, shaving and exfoliating the night beforehand, cleansing preferably with a pre-sunless exfoliation product. These products are designed smooth the skin and cleanse it of any excess dead cells, promoting maximum tanning potential and avoiding uneven application of color. When applying the sunless product, apply to skin in thin layers being careful to limit application on the places of thicker skin, such as knees and elbows. To avoid uneven darkening on these areas, we stock a blending/barrier creams to help minimize the amount of DHA absorption in unwanted areas. We recommend that one completely avoid use of DHA on palms and the soles of feet, and for the technician/customer to immediately wash hands after application. Wearing gloves to administer the product is another way to avoid coloring of hands. Excess solution can be removed quickly with a wet cotton cloth if needed. These solutions and sunless products do stain clothes, so a change into loose fitting clothing or waiting 30 minutes to completely to dry is suggested. Wait at least an hour but preferably 8 hours to bathe, shower or swim. After the tan has developed, moisturize daily to extend the life of the tan and, if applicable, reapply regularly according to directions of sunless product.
Precautions and Side Effects
DHA self-tanners do not provide significant protection to your skin against the sun and should in no way be considered a substitute for SPF sunscreen. A tan in itself, whether gained by DHA tanning or sun exposure tanning, does not provide any worthy UV protection and excessive sun exposure should be avoided unless protected by a sunscreen. Many sunless tanning products do contain additional sunscreen, but the stated SPF for such products should only be regarded as effective for just a few hours after application. It cannot be stressed enough that an overall sun protection product should be used for combating UV rays and sun exposure. Another precaution of sunless tanning regards Contact Dermatitis or Irritant Dermatitis, a skin rash resulting from exposure to allergens or irritants. This reaction is rarely reported but should be watched for, and is likely due to other ingredients such as preservatives in the preparation of the product. Ask your technician to perform a skin patch test if this is a concern.