Skin cancer is the most common type of cancer in Ireland. However, skin cancer is often avoidable with the right protection. In addition to wearing hats and other protective clothing, dermatologists stress the importance of daily sunscreen application, including mineral (or natural) sunscreens.

Natural Sunscreen vs. Chemical Sunscreen

There are two types of sunscreen: mineral (also known as natural or physical sunscreen) and chemical. While the two serve the same purpose—to protect skin from skin cancer, sunburn and premature ageing—they have distinct characteristics.

Ingredients

The only active ingredients in a natural sunscreen are the naturally occurring minerals zinc oxide and/or titanium dioxide. Both compounds have been deemed safe for use in cosmetics by the U.S. Food and Drug Administration (FDA).

Chemical sunscreen active ingredients typically include:

• Oxybenzone
  
• Avobenzone
• Octinoxate
• Octocrylene
• Homosalate
• Octisalate

These chemical sunscreen ingredients are currently approved by the FDA in certain amounts, but are under review. Recent evidence shows some chemical sunscreen ingredients are absorbed into the bloodstream, sometimes surpassing safe levels. The FDA notes additional data has been requested to determine the safety of these ingredients when absorbed.

Method of UV protection

Natural sunscreen creates a barrier between your skin and the harmful ultraviolet (UV) rays from the sun. “Mineral sunscreens work by reflecting the sun,” says Beth Goldstein, M.D., co-founder of Modern Ritual—a holistic skincare line for men—and president at Central Dermatology in Chapel Hill, North Carolina. “There’s some absorption of sunlight by the minerals, but most of its effect is by reflecting the sun.” This physical barrier provides immediate protection once mineral sunscreen is applied.

Chemical sunscreen absorbs into the skin where it then absorbs UV rays before filtering them back out of the skin. There’s typically a 15 to 30-minute delay between applying chemical sunscreen and full-sun protection due to this absorption process, according to Scott Paviol, M.D., a dermatologist at Paviol Dermatology in Charlotte, North Carolina.

As long as they are labelled “broad-spectrum,” both natural and chemical sunscreens will protect your skin from UVA and UVB rays. Both types of rays can cause skin cancer; UVA can also lead to premature skin ageing, and UVB is responsible for sunburn.

SPF

Sun protection factor (SPF) measures the amount of sun exposure it takes to cause sunburn compared to unprotected skin; it does not correlate to the time spent in the sun. For example, you get 30 times more protection with a 30 SPF sunscreen than with no sunscreen at all (as long as you reapply every two hours or more if you’re getting wet). SPF indicates a sunscreen’s protection against UVB rays, not UVA rays, making it crucial to choose a broad-spectrum product.

Natural sunscreens typically have a SPF of about 30 or 40 due to the makeup of their mineral ingredients and the way they’re made. “Lower SPF with mineral sunscreens means you just have to reapply every couple of hours,” says Liia Ramachandra, PharmD, Ph.D, and founder and CEO at EpiLynx by Dr. Liia.

Chemical sunscreens can offer a higher SPF, but experts warn that higher isn’t necessarily better. An SPF 30 product already protects from 97% of UVB rays, per the American Academy of Dermatology Association (AAD). Higher SPF numbers may offer slightly more protection, but no sunscreen can block 100% of UVB rays, the AAD says. Further, higher SPF sunscreens don’t last any longer; they must still be reapplied at least every two hours.

Environmental effect

Unlike zinc oxide and titanium dioxide, the main ingredients in chemical sunscreens cause significant harm to marine ecosystems. Studies show oxybenzone contamination in ocean water is a threat to wildlife, coral reefs and seagrass habitats, so much so that Hawaii banned the sale and distribution of sunscreens containing oxybenzone and octinoxate in 2021.

Studies also find oxybenzone, octocrylene and octinoxate in many water sources around the world, from which they are not easily removed. These chemicals are also known to be present in various species of fish around the world, which researchers worry could affect the food chain.

How Is Natural Sunscreen Made?

The first step to making natural sunscreen is to crush the zinc oxide and/or titanium dioxide into a fine powder, says Catie Wiggy, a licensed clean beauty esthetician and product developer at MyCHELLE, a skincare brand. The powder is then dissolved and mixed in with water or oil, depending on the manufacturer.

Natural sunscreens can be found as sticks, sprays, lotions, creams and even foundations or moisturizers. Older or less mixed formulations may turn very white and will not blend with the skin, says Ramachandra. However, many products on the market are either tinted or do not leave a white residue once applied.

Is Natural Sunscreen Effective?

Dermatologists agree that, when used correctly, mineral sunscreens are effective. “As long as the sun protection factor is high enough (at least 30) and you are applying enough of it to adequately defend your skin from the sun, mineral sunscreens are quite effective,” says Geeta Yadav, M.D., dermatologist and founder at Skin Science Dermatology in Toronto, Canada.

Benefits of Natural Sunscreen

The big benefit of mineral sunscreen is that its natural ingredients (zinc oxide and/or titanium dioxide) are safe and don’t absorb into your skin. The ingredients are also better for the environment, meaning they don’t harm wildlife when you swim in the ocean or when you wash the sunscreen off at home.

Dermatologists recommend using mineral sunscreen for sensitive or acne-prone skin types. Natural sunscreens also “tend to be less irritating and [infrequent] sources of allergic reactions,” says Dr. Goldstein.

What to Consider When Buying Natural Sunscreen

If you’re interested in trying natural sunscreen, consider the following factors when searching for the brand for you:

Broad spectrum. This means the sunscreen protects against both UVB and UVA, two types of UV rays. Both types of rays can cause skin cancer; UVB can lead to sunburn, while UVA plays a role in premature skin ageing.

SPF 30 or higher. Mineral sunscreens don’t use high SPF numbers, but dermatologists emphasize the importance of using one that is at least 30 SPF to ensure sufficient protection.

Ingredients list. Some sunscreens may say “natural” or “mineral” on the label, but contain more chemicals than natural minerals, warns Ramachandra. In addition to looking for natural or mineral labels, she suggests also reading the ingredients list to keep an eye out for oxybenzone and other chemicals. Users can also reference the Environmental Working Group (EWG) Sunscreen Guide to stay updated on the most current sunscreen ingredient recommendations and to check ingredients in the sunscreen of their choice.

Water resistant. Sunscreen with water resistance maintains its protection even when you’re swimming or sweating. However, the FDA notes that no sunscreen is truly waterproof, and all formulas will eventually wash off. Sunscreen labels are required to show the number of minutes for which the sunscreen will remain effective while swimming or sweating, and directions for reapplication.

Favourite formula. Finding a product you like, whether it’s a stick, cream or foundation, is crucial, according to Dr. Yadav. “You need to select a formula that you’ll like and want to reapply,” she says. “After all, if you’re not using your sunscreen, it’s not protecting your skin.”

Luckily, natural sunscreen can be found in many forms, and some formulas are tinted or invisible once they rub in, so you’re not left with a white residue on your skin.