Skin cancer is the leading form of cancer in the US. Because of this, sun protection is one essential of skin care we cannot do without. This is a review on sunscreen basics.

SPF or sun-protection factor, is a number such as 15, 30 or 50 that indicates how long a topical sunscreen remains effective on the skin. One can determine the duration of effectiveness simply by multiplying the SPF by the length of time it takes for him or her to suffer a burn without sunscreen. Persons with sensitive skin who burn quickly and must spend a lot of time outdoors should consider applying a sunscreen with an SPF of 30 or more.

Not all sunscreens protect against all kinds of rays. Those that protect us from UVA and UVB rays, classified as broad spectrum, are our best choices.

What ingredients should we look for in a sunscreen? Of the two more commonly used active ingredients for sunscreens - zinc oxide and titanium dioxide -zinc oxide is proven to block more UV rays.