mnp13 wrote:Why do you say that?
SPF measures how much sun protection the lotion provides, a combination of sun intensity and duration of exposure. The higher the number, the higher the protection. In an ideal world this is true, but this only occurs to an extent. When you get up into the really high numbers (60+) the sunscreen can't provide any more protection against sun intensity and it won't stay on the skin to see an effect with duration. Simple activities will cause the lotion to be absorbed or rubbed off and it is now ineffective. By the time you would see the effect from the higher SPF's the lotion is gone.
The American Academy of Dermatology recommended you use at least an SPF of 15 and reapply sunscreen AT LEAST
every 1.5-2 hrs no matter what the SPF. The FDA is also looking at sunscreen and the SPF rating system and revising it. Some countries you can't label higher than 30+ or 50+ and it looks like the US is going there too.
So why spend more on the higher SPF's when it isn't providing any more protection?? Just my two cents. I burn like no tomorrow and I use 30 or 45 and reapply often about every 2 hours with no problem depending on what I'm doing. I had found a good article a few years ago but I can't find it now. I'll look again when I have more time if you're interested.