Sunscreen: You Should Wear It

This shouldn’t be news to you: you should be wearing sunscreen.

I know. It sucks. Finding one that lasts a sufficient length of time AND doesn’t screw with your makeup application AND doesn’t leave a white cast AND doesn’t look greasy AND doesn’t clog your pores AND has sufficient protection is a frustrating (and expensive) process — especially if you don’t know much about that “sufficient protection” thing. UVA? UVB? SPF? And what the heck is PA?

Let’s start with some ~science~.

If you took any high school science, you learned about the light spectrum. (If you didn’t, I’m going to assume you grew up in Texas. JUST KIDDING but also seriously Texas please work on your science curricula because children are the future.)

The sun emits radiation of different wavelengths, which is why we have different colors (red is the longest wavelength, violet is the shortest). But there are rays outside the visible light spectrum, since our puny human eyes can’t detect ultra-tiny wavelengths. These are ultraviolet rays. (If you ever can’t remember where UV falls on the spectrum, it tells ya right in the name — ultraviolet. Violet is the smallest visible color, so ultraviolet is even smaller.)

So, why are tiny radiation wavelengths a big deal? Because they screw with your cells, that’s why. Visible light may affect your skin in good ways (have you seen those serial-killer-looking LED face masks? Red for wrinkles, blue for acne).

UV light tends to affect it in NOT-good ways.

Just as different visible light colors come in a variety of wavelengths and affect your skin in different ways, ultraviolet rays come in different wavelengths as well.

UVA is the longest ultraviolet wavelength, just a bit shorter than visible violet. UVB is shorter than UVA, and UVC — yes, there’s a UVC — is the shortest. (We don’t talk about UVC one much since it mostly gets screened out by the ozone layer.)

They all do bad stuff to your skin, but they do different types of bad stuff. UVB is the one that seems to do the most damage, as UVB is what causes sunburns. (Boooo hissss) Though sunburns are miserable, they’re not the worst thing that can happen — UVB rays only penetrate the shallow layers of your skin, and pose a lower cancer and photoaging risk. UVB can still contribute to small photoaging and cancer risks over time — it’s safer to have no UVB exposure than lots, obviously — but in terms of long-term health risks it’s not the worst ultraviolet option.

That’d be UVA. UVA deeply penetrates skin, damaging cells in the basal layer of your skin. (This is where the term “basal cell carcinoma” comes from — cancer of deep skin cells.) UVA is also the ultraviolet wavelength most responsible for wrinkles and photodamage, which is why you might get sun spots even if you never tan. UVA is insidious — it makes up 95% of ultraviolet wavelengths, clouds can’t stop it (UVA just passes right through), and — because it causes no noticeable short-term damage or physical pain, you usually don’t even know it’s hurting your skin. (Unlike UVB, which causes a literal “red alert” if you’re exposed to too much of it.)

Here’s the problem with sunscreen: SPF (Sun Protection Factor) ONLY refers to UVB protection. You might grab an SPF 70 sunscreen and think you’ll be fine, but that’s a lie. If it doesn’t say “Broad Spectrum” on the bottle, it only offers UVB protection. “Broad Spectrum” means it includes UVA protection as well, though there’s no current FDA standard for how much UVA protection is contained in a “Broad Spectrum” sunscreen. SPF 70 Broad Spectrum = great UVB protection, and some UVA protection in unknown quantities.

But how do you know how much UVB protection you need? Common sense suggests that much higher SPF = much better SPF, but that’s kind of misleading as far as the actual science goes. SPF 15 offers 93% UVB protection. SPF 30: 97%. SPF 50: 98%. SPF 100: 99%. Notice how doubling SPF from 15 to 30 doesn’t double the amount of protection it offers? And how doubling from SPF 50 to SPF 100 only adds ONE more percentage point of protection?

If your skin is virtually translucent, or your family has a massive history of skin cancer, it might make sense to splurge for SPF 100 rather than SPF 15. (I do my best to stick with SPF 30 or higher, since multiple members of my family have dealt with or are dealing with skin cancer, and I had a biopsy scare when I was only 21.) But SPF 15 is pretty good, too, and when I spoke with my Science Husband about this, his conclusion was that “anything SPF 15 or higher is seriously fine.” He also told me an interesting fact — for standardization purposes (because ~science~), labs test SPF efficacy by presuming a direct 90-degree angle of UV radiation exposure, which is a more severe UV exposure condition than most people experience. (He started talking about latitude and angle of exposure and stuff and that’s when I was like “okay so what level of SPF do you need tho” and he was like “15.”)

There is one small benefit from higher SPF ratings, though — if you tend to underapply sunscreen, a higher SPF will give you a safer margin of error. (Made-up example: applying too little SPF 75 is maybe as safe as applying enough SPF 15. These are not scientific numbers, just a way to illustrate the concept). You know what, though? High SPF products tend to be disproportionately expensive to their 15 and 30 brethren; just spring for an adequate amount of SPF and maybe, y’know, try to apply it properly?

As far as UVA protection ratings go, Korea’s way ahead of the USA on this one (as they tend to be when it comes to skincare). They use SPF ratings for UVB just like we do, but they also have a rating system for UVA — the “PA” system. PA+ is fine. PA++ is better. PA+++? Really good UVA protection! Hurrah! If your “broad spectrum” sunscreen doesn’t come with a PA rating (if it’s an American sunscreen, for example), it’s good to look at the ‘active ingredients’ in sunscreen to see what it contains. Look for avobenzone, oxybenzone, the subscript “benzone” in general, titanium dioxide, and zinc oxide for UVA protection.

There are two types of UVA sunscreens, and pros/cons for each. Physical sunscreens — titanium dioxide, zinc oxide — provide stable UVA protection and may be less irritating; unfortunately, they also tend to have a strong white cast. Chemical sunscreens — avobenzone, oxybenzone — may need to be reapplied more often, and generally need to be formulated juuust right or they’re unstable. (But don’t worry too much about it. Cosmetics chemists are worrying about it for you, and many companies are improving in this regard.)


UVA: invisible. sneaky. evil. cancer. wrinkles. aging. “Broad Spectrum” or “PA+.” Avobenzone, oxybenzone, zinc oxide, titanium dioxide.

UVB: sunshine. sunburn. some cancer. “SPF.”

So now that we’ve gone over the “why” of sunscreen, I’m going to leave you with a recommendation for one of my favorite sunscreens: Biore UV AQUA Rich Watery Gel SPF 50+ PA++++.


it’s a lotta plusses.

If an ounce of prevention is worth a pound of cure, then this little bottle contains 3.04326 pounds of cure. (It’s about 3 ounces, is what I’m trying to say, and costs anywhere from $7 – $15 dollars depending on where you buy it. Darn Korean imports and their lack of standardized American retail prices!) The Biore Watery Gel and Biore Watery Essence both get a lot of love on the internet, and for good reason — quick absorption, no white cast, high UVB/UVA ratings. (I tried both at the same time and don’t remember why I repurchased the gel rather than essence. They’re both fine, though the Essence is more famous.)

They change the bottle styles fairly often — this one is from 2016. I think.

Mine has little specks of white floating in a watery greenish-white base. It spreads over the skin with ease, absorbs almost instantly, and leaves no white cast or annoying residue that might interfere with your makeup application. It is a delight to use. It also smells lightly of tart lemon (which I find very pleasant) because of added fragrance. (Not ideal, but whatever.)

Annoyingly, Biore keeps reformatting these — some have alcohol near the top of the ingredients list while others don’t seem to have any denatured alcohol at all; dimethicone travels up and down the ingredients list; a bottle formatted for sale in Singapore might have parabens while the Korean-market version doesn’t; etc. As the ingredients on the packaging are in Korean, and I do not speak Korean, I’ve learned to cross-reference bottle design with ingredients lists on COSDNA.


If you want to be really careful, go with something that contains either zinc oxide or titanium dioxide. Both of these physical sunscreens provide UVB and UVA protection, and can rub or sweat off but don’t ‘wear out’ over the course of the day, since you have a physical sun-blocking molecule literally sitting on top of your skin. (Chemical sunscreens might ‘wear out’ after applying, even if they don’t rub off of your face.) Physical sunscreens are more likely to leave a white cast and have a nasty texture, but physical sunscreens start working immediately, may last longer, and are less likely to irritate or clog your skin.

But ultimately, the best sunscreen is the one you will wear on a daily basis.

If you can’t find an SPF 30 that you like, but have an SPF 15 you don’t mind? Wear the 15. Does your favorite formula have alcohol in it? A little alcohol is probably better than a lot of cancer-causing UVA damage. (This is how I justify my Biore.) Do you know that your sunscreen is supposed to be reapplied every two hours, even though you have no intention of doing so? Hey, that’s two hours more UV protection than if you weren’t wearing it at all. Does your sunscreen have great SPF but an unknown amount of UVA protection? ANY amount of UV protection is better than no UV protection!

Do you have any recommendations of sunscreens to try (or stay away from)?