Friday, May 11, 2007

Sunscreens... serious business

Since I'm in Brazil, since summer is just getting into gear for most of you, sunscreen seemed like a good topic. It seems that many people don't really understand the SPF system. The Sun Protection Factor is mathematically derived. In layman's terms, SPF is the factor by which your bathing time is reduced... i.e. bathing for one hour with SPF 15 protection, is the equivalent of being in the sun for 4 minutes = 60 minutes divided by 15. Get it? Here's 1000 words. Notice, the decreasing returns as SPF increases exponentially. Also notice, my SPF 20 glistening body; my white skin attracting much attention on the Brazilian coast... I know. With that background, how can you possibly concentrate on diminishing returns? Here's a picture to help: I think we can see anything over SPF 30 is a rip-off, unless you are Powder, and that there really isn't too much difference after #8. We can also see the brilliant gleam of coolness that irradiates from my mohawk, leaving only a pert backside in it's wake, complementing a pelvic region that protrudes ever so slightly outward. No really, don't look at that. Instead look at the prices*.
Did you know you could buy sunscreen on amazon.com? Yeah, apparently you can get a lot more than books there; I'm pretty sure you can actually schedule regular purchases too. Just think, every week you could have a fresh bottle of Jack and a jar of crazy pills delivered to your doorstep! Who says money can't buy happiness? Can money buy increased sun protection? Well, yes of, course... but once you go past SPF 8 you get diminishing returns. I would like to take a minute to comment on the units, "percent of sun's rays blocked per dollar"... my life has reached a new low. Nonetheless, if you can use SPF 15 without any problem, next time you buy sunscreen, save yourself a buck and try out the #8. Sunscreens, serious business.
*In case you were wondering.... all the sunscreen data was for NO-AD sunscreen, because that's what grandma always used at Beaver Lake. They used to have SPF 2, but apparently that was discontinued (at least I couldn't find any online).
Things I learned that no human should ever know:
-The actual formula for SPF is:
where E(λ) is the solar irradiance spectrum, A(λ) the erythemal action spectrum, and MPF(λ) the monochromatic protection factor.
-In a report from the University of California at Riverside, I learned that leaving some sunscreens on for more than one hour without reapplying can worsen the burn from then on... due to the free radicals that are left on your skin after the sunscreen does its job.
-Sunscreen was kind of invented as a necessity for the soldiers during WW2

2 Comments:

Anonymous Shannon said...

I am currently in posession of some SPF 2 products, my friend. I don't think you could buy a tube of SPF 2 sunscreen, but most moisturizers contain some sun protection in them. Usually SPF 2.

Oh, and good to see you're still rockin the 'hawk.

9:09 PM  
Blogger Cassy said...

Hey, thanks for taking the time to get all that nerdy info so I don't have to. If you get bored, here are some fun you tube things to check, search "what what butt," and "tunak tunak tun." Have fun.

11:39 AM  

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