Many years ago I went through the whole "OMG I have malignant melanoma, OMG I'm gonna die!" crap. My cancer-man told me to always wear sunscreen that contains both a chemical screen (the ones that break down) and a physical block (zinc or titanium) and is at least 30 spf.
Kid's or baby's sunscreen is the stuff most likely to have both. I buy tons of it. Chemical screen doesn't wash off, and physical block doesn't wear out. (the chemical screen works by absorbing rays, which breaks it down. The physical block works by reflecting the rays, which won't help if it washes off with sweat or rubs off with clothing.)
Follow the directions on the bottle. If it says to apply 15 minutes before you go into the sun, that's referring to the chemical screen. Do it. If it says to re-apply, that's referring to the whole shebang. Do it.
When in doubt, put on your chemical/physical mix then put on a layer of a pure neutral physical. The physical blocks UVA and UVB, the chemical is your emergency back-up plan.
Best of all.... long sleeves, long pants, and a wide brimmed hat! (not so easy on the bike, eh?)
Last edited by KnottedYet; 07-02-2008 at 07:07 PM.
"If Americans want to live the American Dream, they should go to Denmark." - Richard Wilkinson