The Tanning
Process
Tanning takes place in
the skin's outermost layer, the epidermis. About five percent of the cells in
your epidermis are special cells call melanocytes. When exposed to ultraviolet B
light (short wave ultraviolet), melanocytes produce melanin - the pigment which
is ultimately responsible for your tan. The pinkish melanin travels up through
the epidermis and is absorbed by other skin cells. When exposed to ultraviolet A
light (longer wave), the melanin oxidizes or darkens. This darkening is your
skin's way of protecting itself against too much UV light.
Everyone has the same
number of melanocytes in their body - about five million. But your heredity
dictates how much melanin your body's melanocytes naturally will produce. For
example, the skin of African Americans contains enough melanin to create a black
or brown skin color, while the skin of Caucasians has less melanin and is pale.
In order to most
effectively avoid overexposure, a tan should be acquired gradually, according to
the guidelines prescribed by your salon professional. A sunburn, or eruthema,
occurs when too much ultraviolet light reaches the skin and disrupts the tiny
blood vessels near the skin's surface.
Why does a tan fade?
Cells in the epidermis' germinative layer (also called the living epidermis) are
constantly reproducing and pushing older cells upward toward the horny layer
(dead epidermis), where they are sloughed off in about one month. As your skin
replaces its cells, the cells laden with melanin are removed. So the tanning
process must continue with the new cells