Without question, the most effective treatment for sun damage is prevention. This involves routine use of sunscreen products that are designed to filter, reflect, or absorb UVA and/or UVB rays emitted by the sun. Many different sunscreen chemicals work in different ways. Often chemists will mix two or more sunscreen chemicals together in a formulation. This type of product will filter more ultraviolet rays, and the combination will often also help to filter both UVA and UVB rays. Sunscreen chemicals may either absorb or reflect ultraviolet rays. Frequently used chemicals that absorb the rays are methoxycinnimate, para-amino-benzoic acid (PABA), padimate O, padimae A oxybenzone, methyl salicylate, and benzophenone. Benzphenone and oxybenzone are primarily UVA absorbers, while the other chemicals listed are primarily UVB absorbers. This is why these chemicals are often combined to produce a sunscreen that blocks out a larger spectrum of ultraviolet rays. These screen products are sometimes referred to as broad-spectrum sunscreens.
Nonabsorbing, reflective sunscreen chemicals include titanium dioxide, a pigment that is also frequently used in foundation makeup to give opacity to foundations. Zinc oxide, a well known sunscreen, is the chemical often used by surfers on their noses. Zinc oxide is also used in sunscreen products. Both of these chemicals reflect ultraviolet rays, rather than absorbing them. Their main advantages are that they reflect large amounts of ultraviolet rays and that they are less likely to cause allergic reactions than the absorbing chemicals. Their main disadvantage is that they are opaque and can be seen on the surface of the skin. Esthetically, many people will not use these products because, even in a refined form, they have some color and often appear pasty on the surface of the skin. A new form of micronized titanium dioxide has been developed and may in the future prove useful in sunscreen products, because it is less likely to be seen.
Sunscreen products may be either a cosmetic or a drug. Cosmetics that contain sunscreen usually do not make major claims concerning the products' sunscreening effects. This does not mean, necessarily, that the product is inferior. It simply means that the product contains sunscreen chemicals, but the company is not making any claims regarding how strong the sunscreen ingredient is. Cosmetic companies often do this to avoid the expensive testing of the strength of the sunscreen and to avoid listing the product as a drug with the FDA.
S.P F. stands for "sun protection factor." This is a rating system that tells how long you can stay out in the sun while using the product without burning. It is not exactly a measurement of sunscreen strength, as the length of burn-exposure time varies greatly from individual to individual. If a person's skin normally burns in one hour without sunscreen, an SPF 2 sunscreen theoretically will allow the person to remain in the sun two times as long, or two hours, without burning. An SPF 4 sunscreen would allow the skin to be exposed four times as long, or four hours, without burning, etc.
