How Physical & Chemical Sunscreen Differ, According To Experts
Let’s be honest: Even though you’re supposed to wear SPF year-round, you’re probably more diligent about it in the spring and summer when you can actually see the sun. Which means right now, you’re likely in the market for a new seasonal sunscreen and wondering what kind of SPF to choose. Finding your perfect formula is always a process of trial and error (I’m nearly 30 and only just discovered my Holy Grail) — but a little dermatological guidance can help, especially when it comes to determining the difference between physical and chemical sunscreen in relation to both sun protection and your particular skin.
“A physical sunscreen primarily works by deflecting ultraviolet rays,” Dr. Sejal Shah, a dermatologist and the founder of SmarterSkin Dermatology, tells The Zoe Report. Physical sunscreens are also known as mineral sunscreens, and the entire category is made up of only only two natural ingredients: zinc oxide and titanium dioxide. “A chemical sunscreen protects the skin by absorbing ultraviolet rays and converting them to heat through a chemical reaction,” the dermatologist adds. Common chemical actives in sunscreen include avobenzone, oxybenzone, ensulizole, and octinoxate; all four of which were recently found to absorb directly into the bloodstream by the Food and Drug Administration (FDA).
“I don’t prefer one over another,” Dr. Loretta Ciraldo, the founder of Dr. Loretta Skincare (and one of the first dermatologists to study the sun’s effects on the skin in the 1970s), tells TZR. “Instead, my advice to all patients is to use a sunscreen that you like.” Which, admittedly, is easier said than done.
Ahead, everything you need to know about physical and chemical sunscreens — including which is best for sensitive skin, and the potentially harmful chemicals that have been banned in certain states — in order to find the right formula for you.
“Zinc oxide and titanium dioxide are the only physical sunscreens,” Dr. Shah explains. “They are both considered broad-spectrum, but titanium dioxide does not protect as well from UVA rays as zinc oxide does.” For this reason, you’ll usually find sunscreens that boast zinc oxide as the only active ingredient (like Love Sun Body’s products or Kari Gran Three Sixty Five SPF) or a mixture of zinc oxide and titanium dioxide.
The main advantage of mineral sunscreens? They’re easy on sensitive skin. “They are less likely to cause irritation and less likely to clog pores,” Dr. Shah says. “They are also better for those with heat-reactive skin (rosacea, for example) as they deflect heat and energy away from the skin.” In fact, zinc goes so far as to actually soothe inflamed skin — that’s why it’s a key ingredient in diaper rash creams.
Also in the “pro” column: Physical sunscreens are natural, start working as soon as they’re applied, and carry virtually no risks. “Zinc and titanium are the only sunscreen actives labelled by the FDA as Category 1, meaning they are considered safe and effective,” Dr. Loretta says. (Chemical sunscreen ingredients are considered to have “insufficient data” to determine a safety rating.)
Another advantage is the longevity of physical sunscreens. "They're more stable and therefore usually have longer shelf lives," Dr. Hadley King, MD, a New York City dermatologist, says. "Expiration dates are stamped on sunscreen containers to specify the time limit for the product's stability and efficacy. For optimal sun protection as well as texture, stability and sterility, use the sunscreen prior to the expiration date."
Alas, mineral sunscreens do have a couple of cons. “They don’t blend into skin as well, and often leave a white cast,” Dr. Loretta tells TZR — although modern brands have found solutions to the white-cast problem with natural tints like cacao powder and color-adapting pigments. These ingredients aren’t always sweat-proof or water-proof, so they need to be reapplied consistently.
While chemical sunscreens have some definite aesthetic benefits — “they tend to be thinner, so spread more easily, and they do not come off as easily in water or while sweating,” per Dr. Shah — many prominent chemical SPF actives have come under scrutiny lately.
In early May 2019, the FDA released new research that proves four common chemical sunscreen ingredients absorb directly into the bloodstream (specifically, avobenzone, oxybenzone, octocrylene, and ecamsule). Within hours of application, the chemicals’ presence in the human circulatory system shot up to “concentrations above the FDA’s toxicology threshold,” as reported by Wired, and remained elevated for three days post-application. Further studies need to be conducted to determine what, if any, health threats this information implies. “Based on what we know today, the benefit of wearing sunscreen in protecting the skin against skin cancer and premature aging outweighs the potential risks,” Dr. Joshua Zeichner, MD of Zeichner Dermatology tells The Zoe Report. He suggests that those concerned about the recent FDA findings use mineral sunscreens.
What’s more, oxybenzone “may damage coral reefs,” Dr. Loretta says, “and is already illegal to use in Key West and Hawaii as of January 2021.” The ingredient has also been shown to prompt allergic reactions and “may be an endocrine disruptor,” according to the dermatologist — so, in other words, it has the potential to mess with your natural hormone levels. The same can be said of octinoxate. Although Dr. Loretta notes this active “goes on smoothly, not pasty,” she also tells The Zoe Report the ingredient isn’t easily removed from water in waste treatment plants — meaning it can contribute to pollution levels.
One alternative, avobenzone, makes for a solid shield against UVA rays, but doesn’t protect against UVBs. “It also degrades quickly when exposed to sunlight — i.e., as you are wearing it — and it can lose its efficacy by about 50 percent,” Dr. Loretta adds.
“Chemical sunscreens are more likely to cause irritation, so may not be ideal for sensitive skin, and they may exacerbate heat-sensitive skin conditions as they increase the skin temperature,” Dr. Shah tells TZR. “They also require time to start working, so chemical sunscreens need to be applied 15 to 20 minutes before being exposed to UV radiation.”
So, Which Is Right For You?
“If someone has sensitive skin or skin conditions that may be reactive to heat, I do tend to recommend mineral sunscreens,” Dr. Shah says. “But in general, I advise using a sunscreen you will use.” In other words: If the fact that a mineral sunscreen may require more frequent reapplication is a deal-breaker for you, it’s fine to opt for a chemical version — so long as you’re aware of the risks and rewards of each.
However, Dr. King has an affinity toward mineral formulas specifically. "I recommend physical sunscreens because they block a wide range of UV wavelengths and they are photo-stable," she says. "And there are fewer concerns about their potential adverse effects both to the body and to the environment. Plus, they have come a long way from their chalky, white, hard-to-spread predecessors. There are now many brands making physical sunscreens that are easy to apply and look great."
Ahead, the 14 mineral and chemical SPF formulas to keep your skin safe through spring, summer, and beyond.
Shop Physical Sunscreen
"It provides not only 100% mineral broad spectrum SPF 50+ sunscreen but it also contains DNA repair enzymes to help address previous sun damage," Dr. King says. "It's all zinc oxide and it also contains antioxidants and DNA repair enzymes-- which means it's actually repairing and protecting at the same time. The texture is lightweight and easy to use."
This formula is a tinted moisturizer with broad-spectrum SPF 45. The physical blocker with zinc oxide and titanium dioxide, boasts a lightweight consistency and coverage.
"It's a great solution for people who don't want to reapply sunscreen because they don't want to mess up their makeup," Dr. King says."It absorbs excess oil so it can serve a dual purpose as a finishing powder, actually extending the life of your makeup, and providing sun protection."
Clean beauty brand Meow Meow Tweet's Everyday Sunscreen just launched this month. It features a 20 percent concentration of uncoated zinc and is safe for use on face *and* body.
I started using this SPF from Kari Gran a few months ago, and I'm certifiably obsessed. Its oil-like texture — care of zinc and antioxidant red raspberry seed oil — effortlessly blends into my skin without the dreaded white tint, and is the only thing I've found that doesn't irritate my (incredibly) sensitive face.
What's inside: zinc and vitamin C, which block UVA and UVB rays and repair signs of sun damage, respectively. What's not inside: chemical sunscreens, parabens, or silicones.
Looking for a mineral sunscreen that works for the whole family? Check out Beautycounter's Countersun, which is safe on sensitive skin, baby skin... any kind of skin, really.
EiR's mix of zinc and cocoa powder is reef-safe, skin-safe, and water-resistant.
Kopari's coconut water, zinc, and hyaluronic acid formula not only reflects UVA and UBA rays, it also helps keep your face moisturized.
Brush On Block's powder formula is a mineral blend of zinc oxide and titanium dioxide with a buildable tan tint to prevent potential blending disasters.
Slather on this 100 percent natural (and fragrance-free!) option from Love Sun Body to stay safe from the sun *and* harmful chemicals.
If you prefer a spray option, COOLA's got you covered with its zinc-spiked mineral sunscreen.
Shop Chemical Sunscreen
Made with both physical and chemical sunscreens, DNAEGF Renewal's SPF 50 option also includes algae-based DNA repair enzymes to prevent sun damage (as well as the resulting fine lines and sun spots).
BlackGirlSunscreen's signature formula is free from oxybenzone, and instead relies on avobenzone, homosalate, octisalate, and octocrylene to absorb the sun's rays. Bonus: It's completely clear.
A moisturizer and sunscreen in one, Supergoop!'s Superscreen Daily Moisturizer features avobenzone, homosalate, and octisalate alongside hydration-boosting glycerin.
This cult-favorite SPF from Dermalogica uses "advanced Oleosome encapsulation technology" that "increases SPF performance while using fewer chemical sunscreens," according to the brand's site. As a result, avobenzone and octinoxate are included at lower concentrations than normal (3 and 7.5 percent, respectively).
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