just an FYI from a former QA guy who was in the industry - don't reuse last year's sun block - SPF begins to declaine after 8 months & pretty havles its stated value after a year - start fresh each season
Are you sure? The FDA requires sunscreens to maintain their effectiveness for 3 years.
I learned quite a bit about sunscreen chemistry in a patent infringement case for Coppertone and I don't know why a sunscreen's chemicals, if the bottle is kept in a cabinet, would deteriorate over time. But it would if the bottle is kept in the sun/heat.
On the other hand, after application, sunscreen effectiveness is affected by sunlight. That's how it works. You're supposed to reapply every 2 hours. You're also supposed to use about an ounce per application, which is way more than I've ever used.
Also, 50 is only marginally better than 30, and over 50 is barely any better than 50. Much more bang for your buck with reapplication.
When fishing, I use spray, since i don't want it on my hands. I know someone that applies it with nitrile gloves.
Don't let the spray get on your bait or lures.
