The first installment in this mini series on sunscreen covered UVB rays, which if you remember, can be easily recalled by ‘B is for burning.’ These are the rays that the SPF number on your tube of sunscreen warn you about (and protect you from). But, these are not the only ultraviolet rays to reach the earth (and YOU!). Longer in wavelength than UVBs, but shorter than visible light, UVA rays can be remembered by ‘A is for aging.’ Ain’t nobody got time for premature aging, but unfortunately aging isn’t the only gift these long rays bring.
It’s the longer wavelengths that make UVA rays so damaging to our skin. These rays penetrate to the deepest layers of the skin (UVBs aren’t so insidious), causing photo aging (premature aging) and are now thought to cause skin cancer as well.
The longer wavelengths also penetrate clouds. This means your ‘I don’t need sunscreen today, it’s cloudy’ excuse to not put on sunblock is leaving you exposed to the most dangerous UV rays. Yes, you may not get burned … but you remember Magda, right?
UVA: How to protect yourself from these rays
So, apart from hiding indoors, how do you protect yourself from UVA exposure? ‘Easy,’ you say, ‘I just wear sunscreen. Duh.’ And yes, you’re right, it’s that easy. Except, it’s not.
It’s not that easy because, unlike the SPF system for UVB rays, there is no standardized system that quantifies how much of these rays a sunscreen blocks. In North America and Europe, a manufacturer can write “broad spectrum” on the label in addition to the SPF number, which indicates it blocks UVAs. How much of the UVA rays that reach your skin are blocked? Well, they have to block at least 1/3 the amount of UVBs they block. That’s the only requirement, and they don’t tell you what the actual percentage is.
It’s a little better in Asia. Most Asian manufacturers use the PA+ system. It ranges from PA+ to PA++++. And as you may have guessed, mo plusses are mo bettah. Except … the system isn’t numerical and transparent like the SPF scale is. It’s just … better coverage with more plusses. The consumer is left in the dark on exactly how much better.
UVA: What ingredients block UVAs?
In the U.S., the FDA approves a few active ingredients that protect against UVA rays, including the following: zinc oxide, titanium dioxide, avobenzone, and ecamsule (or Mexoryl SX, which is patented by L’Oreal).
Outside the U.S., there are other (more effective, but that’s info for another installment) active ingredients that protect against UVA rays: Tinosorb S, Tinosorb M, Uvinal A, and Mexoryl XL. To simplify things, a smart consumer should look for more than one of these ingredients; some of these protect against UVA-1 rays and some against UVA-2. And no–of course, the “broad spectrum” or “PA+” designations do not mean they protect against both types of UVA. Because that would be helpful.
That’s about it for this super brief overview on UVA rays. Just remember: UV-Burning and UV-Aging, and if you are using a chemical sunscreen (which again will be a topic for another day), looking for more than one active ingredient generally means you’re getting truly broad spectrum coverage (i.e. covering both types of UVA).
The following are affiliate links to fully broad spectrum sunscreens. They cost you nothing extra to buy from but can provide me with some dinero.