We’re coming up on summer, and while I will always harp on you that you should wear sunscreen every.damn.day, no matter the season or weather; summer is even more crucial. Longer days, higher UV indexes and more time outdoors (with more skin exposed) means it’s time to get serious on sun exposure. Today, I’m starting a multi-part series (how many parts? Who knows?!) on deciphering sunscreen so you know exactly what you’re buying. First on the docket: UVB rays. What they are, and why you care (and yes, you should care).
What the hell are UVB rays?
OK, so the sun sends down its ultraviolet, or UV, rays to us here on earth. You can’t see them because their wavelength is shorter than the rays in the visible spectrum (the ROYGBIV!). UV rays are organized into three main groups, UVA with the longest wavelengths, UVB in the middle, and UVC with the shortest wavelengths.
UVC rays are so short the all-powerful ozone layer absorbs them. Yay for the ozone! Yay for us! So we will move onto the middle class of ultraviolets, UVB. UVB rays can be remembered by “B for burning.” These rays hit the surface layers of the skin and, you guessed it, cause sunburns.
UVB Rays: How to Avoid Them
The upside to UVB exposure: the entire SPF system (which is standardized worldwide, hooray!) is set up to inform consumers sunscreen protection levels from these rays. Once blamed for causing not only sunburns but skin cancer, UVB rays are effectively blocked by many different active ingredients, and the results of sunblocks containing these are very transparent to consumers.
SPF, or Sun Protection Factor, informs consumers what percentage of UVB rays are blocked (when using an appropriate amount of product).
SPF 15 blocks 93% of UVB rays
SPF 30 blocks 97% of UVB rays
SPF 50 blocks 98% of UVB rays
So you see, the scale is not linear. SPF values above 50 offer almost no additional protection over 50 factor (in fact, in Australia, sunscreen manufacturers are barred from advertising any SPF above 50 to avoid a false sense of security for consumers). If you are shopping for sunscreen in Asia, you will also find manufacturers do not promote more than SPF 50+ on their products as well.
That’s pretty much it on UVB … aka medium length ultraviolet rays that cause burns and penetrate shallower layers of your skin. Very dangerous in the short term. Use an appropriate amount of SPF30 or greater and reapply as directed and you should be able to avoid most of these bad boys. Up next, the most insidious of UV rays, the long and strong UVA rays, or, the component of sunshine that will turn you into Magda and can literally kill you.
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