Sunscreen with SPF 15 is recommended for most of us (up to SPF 30 if you have fair skin or burn easily), which -- when used correctly -- will block about 93 percent of the sun's damaging UVB rays. Be sure to apply 15 to 30 minutes before you go outside to allow it time to soak into your skin.
There are two basic types of sunscreen: One type absorbs UV radiation before it can damage your skin, and the other blocks or reflects the rays before damage can occur. Sunscreens with organic ingredients, also known as chemical sunscreens, are sunscreens that absorb UV radiation.
Chemical sunscreens are absorbed into our skin and protect us from UVA or UVB rays (or sometimes both) with ingredients such as avobenzone (also known as Parson 1789), cinnamates, retinyl palmitate, salicylates, and benzophenones such as diozybenzone, oxybenzone and sulisobenzone. While organic sunscreens can be some of the best topical sunscreen options for oily skin because they are offered in oil-free, light-weight formulas, it's important to be aware that some ingredients (including avobenzone, oxybenzone and retinyl palmitate) in these chemical sunscreens are under investigation because of concerns they may cause allergic reactions, may be linked to certain cancers or may be disruptive to people's endocrine systems.