The Sunscreen Glossary: A Comprehensive Guide to Everything You Need to Know About SPF
Here's how to decipher all the terms on a sunscreen label.
Buying sunscreen used to involve choosing an SPF level and deciding if you wanted to smell like a coconut. Today, the descriptors on each bottle have multiplied, and there are far more decisions to make. We’re here to help.
Sunscreen ingredients can already be a bit of brain teaser for the average shopper — do you choose a formula with zinc oxide, titanium dioxide, a combo of both, or something else entirely, like a non-mineral filter? — but when you add in other words from elsewhere on the label, the challenge of choosing the right protection multiplies exponentially. How much of the language is just marketing mumbo-jumbo, and which terms should be taken into serious consideration? And more importantly, what do they all mean?
Here, you’ll find explanations of the most common words and phrases found on sunscreens so you can approach the shelves (or the websites) with the confidence that you’re getting what you want and need, whether that’s a formula that won’t irritate your skin, one that won’t harm the environment, one that won’t budge when you sweat, or all of the above — and then some.
A sunscreen that offers protection from both UVB rays, which burn skin, and UVA rays, which cause damage like collagen breakdown, For the best sun protection, use only sunscreens labeled “broad-spectrum.”
A term used to describe a sunscreen that protects from UV rays by absorbing them with chemical ingredients, such as octocrylene or avobenzone (though it’s worth noting even “mineral” sunscreens are made in labs).
adj. kli-ni-kl te-std
Some brands test for distinctions like being good for sensitive skin, but seeing this term doesn’t indicate which benefit they tested for, nor on how many people, So it shouldn’t sway your choice.
The Gluten Intolerance Group will place its GFCO seal on beauty products with 10 parts per million or less of gluten. (But gluten-containing ingredients, like wheat protein, are more common in hair care than sunscreen.)
The FDA doesn’t regulate this term (see “Caveat Emptor,” below, for more on that), and companies can use it whether or not they’ve formulated a product with a low likelihood of triggering allergic reactions. If you tend to react to sunscreens, look for a fragrance-free mineral formula.
These sunscreens achieve their SPF factor with physical blockers, like titanium dioxide and zinc oxide, (They form a physical barrier between UV rays and skin.)
There’s no standard way to validate whether a beauty product is likely to cause comedones (pimples). But if you’re acne-prone, choose sunscreens with drying salicylic acid and zinc oxide, and avoid ones rich in lipids, like coconut oil and cocoa butter.
This means a product doesn’t contain oil, but it doesn’t indicate whether it has other occlusives, like silicone, that can cause breakouts and even heat rash. If you’re concerned, look for a sunscreen that skips both oils and silicones. You can find silicone by looking for names that end in “-siloxane” or “-thicone,”
While this can mean that a sunscreen’s botanical ingredients were farmed organically (look for the USDA seal), no sunscreen can be 100-percent organic. Chemical sunscreens rely on lab-concocted compounds to protect from UV rays, and physical ingredients “are synthetically created — it is illegal to use mined versions of zinc and titanium dioxide since they are contaminated with dangerous levels of heavy metals,”
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Either term should mean that a sunscreen doesn’t contain any of these five ingredients: oxybenzone, octinoxate, octocrylene, 4-methylbenzylidene, and butyl-paraben, Small studies suggest that these ingredients can affect coral’s ability to reproduce by harming or killing coral larvae and even reduce its life span and immunity. Still, these are unregulated terms, so double-check the label for any of the above ingredients if reef safety is a priority. (Reef-safe sunscreens may also be labeled “biodegradable,”
There’s no standard for just how sand-repellent a sunscreen is, but some independent labs offer tests for sunscreen makers who want to make this claim. “It means that when the sunscreen was exposed to several different sands — fine, medium, and all-purpose — the SPF level didn’t change. This is usually due to smoother, silkier textures that don’t allow sand to ‘cling,’ ”
You’re better off looking at the back of the label than the front to determine whether or not a sunscreen is good for sensitive skin. Opt for physical sunscreens instead of chemical ones, since they’re less likely to irritate skin, and look for options without “fragrance,” another top offender, listed on the ingredient label.
Stands for sun protection factor, specifically for UVB rays. The number next to it is a measure of how much solar energy is required to produce a sunburn on protected skin — as the SPF value increases, so does sunburn protection. (It’s not a measure of UVA protection — another reason to choose broad-spectrum sunscreens.) The FDA’s standard for testing is to apply two milligrams of sunscreen per square centimeter of skin. Or, in medical terms: “A really thick layer,”So the higher that number, the better.” I recommend a minimum broad-spectrum SPF of 30 year-round, and an SPF of at least 50 for beach days or outdoor activities in the summer. Reapply every two hours to stay protected.
Since there’s no actual test to verify that a sunscreen is better for activities, any sunscreen that’s qualified as water-resistant for 80 minutes will do the trick.
In the U.S., the FDA regulates this term via one standard test: A subject alternates between getting wet and drying off multiple times and is then tested to be sure the sunscreen is still on and in effect. All sunscreens that use the term “water-resistant” are required to undergo the test, so look for the stamp if you know you’re going to be swimming or sweating. The Australian government’s Therapeutic Goods Association requires that sunscreens remain fully present on skin after four hours of water exposure. You can seek out sunscreens, like ones from TropicSport, that are sold in both countries and have passed both tests.