Re:Time to sunburn
by thehappypm on Tuesday June 15, 2021 @05:16PM
(#27521614)
If you're standing under a UV light that's constant, I think the SPF === time works. In the real world, where the sun, ya know, rises and sets, this is actually a harmful assumption.
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The FDA's article gives a meaninglessly useless. The multiplicative one is clear. What is the plausible case where someone gets confused by this in a way that's harmful? Would anyone ever over-estimate the time they can spend in the sun? I can only imagine under-estimating that time (which is fine) since our base reference for sunburns is always to picture the hottest day of summer at the beach at middday - the worst case scenario. The sun setting makes this better not worse!
Either way the multiplicative one is clear: 30 minutes of midday exposure with 30 SPF is approximately equal to 1 minute of midday exposure and so is minimal. That's helpful to know! And 50 is only moderately better than 30, but 30 is a lot better than 10 - the FDA page says nothing about this.