Comments on: Is higher SPF in sunblocks better?

By: sesame

sesame — Thu, 07 Jul 2011 12:56:51 +0000

That’s what I wrote in the entry isn’t it? The time is just another way to look at it.

By: Sarah

Sarah — Thu, 07 Jul 2011 10:57:17 +0000

SPF indicates how MUCH UVB is blocked.

So SPF 15 allows 1/15 of UVB to reach your cells – it blocks about 93% of UVB.

SPF 30 allows 1/30 of UVB through – it blocks about 97% of UVB.

SPF 50 allows 1/50 through, blocking 98% of UVB.

And an SPF of 100 would allow 1/100 through, blocking 99% UVB.

Notice SPF has nothing to do with UVA penetration.

SPF measures how much UVB passes through. It still needs to be reapplied every two hours because the chemicals breaks down at the same rate, regardless of SPF.

By: sesame

sesame — Mon, 04 Jul 2011 01:11:46 +0000

Why is it incorrect? What’s correct then? So the Skin Cancer Foundation is wrong in that regards?

By: Cat

Cat — Sun, 03 Jul 2011 16:49:29 +0000

The SPF number has nothing to do with time. That statement is incorrect. The higher the number does not mean one can stay out x minutes longer or one can stay out x times longer.

By: Andrea @ Mineral Cosmetics

Andrea @ Mineral Cosmetics — Wed, 29 Dec 2010 02:08:01 +0000

There’s is a misconception about higher spf. Wearing higher spf sunscreen does not mean you can stay out in the sun longer without reapplying it.