SPF: Sun Protection Factor. Apply to areas that are exposed to sun, reapply as needed to maintain the SPF protection, especially after long exposure to the sun such as exercise, sport activity or swimming. Recommended for clients using Alpha Hydroxyl Acids, and Retinol products. Recommended for clients after laser treatments and chemical peels. 

Definition: Sunblock is different than sunscreen. A sunblock physically blocks the sun's UV radiation of the skin, both UVA and UVB. Examples of sunblocks are clothing, umbrellas, and trees. Chemical sunblocks scatter, reflect, and physically block UV radiation. The most commonly used chemical sunblocks are zinc oxide and titanium dioxide.

A new sunblock formulation has been developed that contains micronized titanium dioxide and zinc oxide. The advantage of this formulation is that it is almost invisible and still has good UV blocking capabilities. Some sunblocks have some disadvantages. Many older chemical sunblocks are opaque, the skin can not be seen through the sunblock. This may not be cosmetically acceptable for many people. They can also be greasy and clog pores, a problem for people with acne-prone skin.