Updated: Jul 26, 2021
Here’s what you need to know.
How Do Chemical and Mineral Sunscreens Work?
Chemical and mineral sunscreens shield your skin from the harmful effects of the sun’s UV rays in very different ways.
“Mineral sunscreen [ingredients], zinc oxide and titanium dioxide, are small particles that sit on the skin’s surface and physically prevent UV rays from penetrating the skin,” says Jennifer L. MacGregor, MD, a board-certified dermatologist at Union Square Laser Dermatology in New York City. You can also apply mineral sunscreens on top of other skin-care products.
Chemical sunscreens, on the other hand, allow UV light into the skin. Once the light is absorbed into the skin, the chemicals in the sunscreen (the AAD lists oxybenzone, avobenzone, octisalate, octocrylene, homosalate, and octinoxate) create a chemical reaction in which UV light is converted to heat, and the heat dissipates from the skin, says Lauren Ploch, MD, a board-certified dermatologist in Augusta, Georgia.
Chemical vs. Mineral Sunscreen: Is One Type Safer?
The U.S. Food and Drug Administration (FDA), which regulates sunscreen products, hasn’t labeled either type of sunscreen unsafe. But as of February 21, 2019, the FDA has proposed a rule to update regulatory requirements for sunscreen products sold in the United States.
As part of this proposed rule, the FDA has called for additional safety information on 12 active ingredients commonly found in chemical sunscreens: oxybenzone, avobenzone, octisalate, octocrylene, homosalate, and octinoxate.
A small randomized clinical trial published in May 2019 in the Journal of the American Medical Association (JAMA) revealed that four of these sunscreen chemicals (avobenzone, oxybenzone, octocrylene, and ecamsule) are absorbed into the bloodstream at significantly greater levels than 0.5 nanograms per milliliter (ng/mL). That’s far above the amount at which the FDA requires topical medications to undergo safety studies to determine possible toxic effects.
These results were echoed in a follow-up study published January 2020 in JAMA Journal of the American Medical Association, though this research looked at six sunscreen chemicals (avobenzone, oxybenzone, octocrylene, homosalate, octisalate, and octinoxate).
Although study authors say these results support the need for more research, they also say their findings don’t indicate that sunscreen is unsafe. What’s more, the known health risks of sun exposure far outweigh the potential risk of absorbing sunscreen chemicals.
Still, the Environmental Working Group (EWG) recommends avoiding chemical sunscreens with oxybenzone because of concerns that this ingredient may disrupt hormones and cause allergic skin reactions.
Dr. MacGregor also warns against using chemical sunscreens when swimming in the ocean. A review published in January 2019 in the Journal of the American Academy of Dermatology found that common chemical sunscreen ingredients such as oxybenzone may bleach and damage coral reefs. For this reason, some tourist destinations, including Hawaii, have banned oxybenzone, as the Center for Biological Diversity notes.
A study published in May 2021 in the journal Nature Scientific Reports found that methylene blue, a common laboratory dye and medication, shows promise as an alternative sunscreen ingredient that’s both effective for blocking UVA and UVB rays and safe for the environment.
Meanwhile, the ingredients in mineral sunscreens — zinc oxide and titanium oxide — have been generally recognized as safe and effective by the FDA.
The Pros and Cons of Mineral and Chemical Sunscreens
The Pros of Chemical Sunscreen
Chemical sunscreens are quick and easy to apply, and unlike mineral sunscreens, they don’t leave a white film on the skin. What’s more, chemical sunscreens statistically perform better on consumer tests that look at how long they protect the skin from UV rays, Dr. Ploch says.
The Cons of Chemical Sunscreen
Chemical sunscreens may cause skin reactions in certain people. Ploch says chemical sunscreens can cause allergic reactions in people with sensitive skin, and worsen melasma and rosacea. According to the AAD, melasma is a common skin condition that results in brown patches on the face, forearms, and neck, while rosacea results in red patches and small pimples on the cheeks, nose, and forehead.
The Pros of Mineral Sunscreen
The two most common ingredients in mineral sunscreens, titanium dioxide and zinc oxide, are the only sunscreen ingredients generally recognized as safe and effective by the FDA. “[Mineral sunscreens] are much safer for people who are concerned about long-term exposure to chemical ingredients,” Ploch says.
Mineral sunscreens are also ideal for children, people with sensitive skin, and people with melasma. “The heat dissipation of chemical sunscreens can exacerbate melasma,” Ploch explains.
And unlike chemical sunscreens, which typically take 20 to 30 minutes to absorb into the skin, mineral sunscreens offer immediate protection — no waiting needed. Mineral sunscreens can also be applied on top of makeup and other skin-care products.
The Cons of Mineral Sunscreen
Because mineral sunscreen is thick and sits on top of the skin, it may contribute to breakouts in people prone to acne. “Acne-prone or combination skin may benefit from a combination of both mineral and chemical ingredients,” Ploch says. Meanwhile, MacGregor recommends combination sunscreen products with anti-acne additives like niacinamide (EltaMD 46 UV Clear is one option).
Mineral sunscreens are also harder to apply, tend to leave a white film on the skin (thanks to the presence of titanium dioxide and zinc oxide), and need to be applied more frequently than chemical sunscreens, Ploch says.
Still, mineral sunscreens have come a long way over the years, and there are options on the market that won’t leave a white cast on your skin. “Ask an expert and try a few to find one you like,” MacGregor says. She recommends EltaMD, Alastin, and Isdin.
Bottom Line: Mineral Is Best, but Something Is Better Than Nothing
Between the two types, mineral sunscreens are generally the better, healthier option. “I tell my patients that mineral sunscreens are like a healthy, home-cooked meal, [while] chemical sunscreens are like the fast food of sunscreens.” Ploch says. Mineral sunscreens typically take longer to rub into your skin and need to be applied more frequently, but they may be safer for long-term use.
That said, some sunscreen is better than none. The FDA recommends using broad-spectrum sunscreen (these protect you from both types of UV rays: UVA and UVB) with SPF values of 15 or higher, making sure to reapply at least every two hours.