How to Select the Best Sunscreen

Check out the tips below for selecting the best sunscreen, I discovered this chart at sunprotection.net.

• Select a broad spectrum sunscreen (blocks both UVA and UVB). How can you tell? Look for a 4% or higher level of one of the following: zinc oxide, micronized zinc, titanium dioxide, Parsol 1789, avobenzone.
• Choose a sunscreen with a Sun Protection Factor (SPF) rating of 30 or higher.
• Be sure that your sunscreen is appropriate for your fun-in-the-sun activity. (i.e. Waterproof for swimming, non-irritating for sports, etc.)
• Test it first! Make sure that it doesn't irritate your skin, but also, be sure that it's comfortable for you personally. If you can't stand a greasy feel, be sure to choose one that feels lighter. Scent is also another factor to consider.

I also found it interesting what the SPF rating actually tells you. It's not the percentage of protection unto itself, but it does tell you percentage of protection against UVB (sunrays with wavelengths between 280 and 315 nm). To figure out percentage of protection, take the SPF rating, subtract 1, then divide by the rating.
So, a sunscreen with SPF 40:
40 - 1 = 39
39 / 40 = 0.975
= approximately 98% protection against UVB rays