The answer is yes, there is a safe way to tan. However, it is not the kind of tan you get from sunlight or a tanning booth. In fact, it is not really a tan in the true sense of the word (a true tan is a darkening of the skin caused by increased melanin pigment formation that results from damage to the skin caused by UV rays).
By using a "quick-tanning" product containing a chemical called dihydroxyacetone, it is possible to temporarily darken the surface of the skin in a way that can simulate the appearance of a true tan. These quick-tanning products do not injure the skin the way that UV rays do. In fact, some light rays are actually blocked to a small degree by the use of a quick tanning product.
One drawback of a quick-tan is that it fades quicker than a regular tan. However, the skin surface will again quickly darken after reapplying the quick-tanning product. Quick-tanning products have traditionally been made available in the form of creams or lotions that are applied to the skin. However, a new product call "Mystique Tan" has recently appeared in tanning salons that is sprayed on the entire skin surface (much like taking a shower) in order to get a uniform quick-tanned appearance all over.