Distinction Between Chemical and Mineral Sunscreen

Many of us enjoy a day in the sun. Sunlight can cause skin damage such as burns, blisters, and even skin cancer.

The American Academy of Dermatology reports that nearly 20 Americans die each day from melanoma, the most deadly form of skin cancer. How do you get melanomas? Exposure to ultraviolet (UV) light, such as that from tanning beds and the sun.

Fortunately, you can reduce the effects of sun exposure by using sunscreen daily. A September 2018 JAMA Dermatology study shows that regular sunscreen use in young adults reduces the risk of melanoma. The Journal of Clinical Oncology reported that regular sunscreen use prevented melanoma in adults.

But not all sunscreens are equal. There are two main types: chemical and mineral.

How Do Chemical and Mineral Sunscreens Work?

Chemical and mineral sunscreens work differently to protect your skin from the sun’s UV rays.

Skin-protective minerals like zinc oxide and titanium dioxide are small particles that sit on the skin’s surface and physically block UV rays from penetrating, says Jennifer L. MacGregor, MD, of Union Square Laser Dermatology in New York City. Mineral sunscreens can be applied to other skincare products.

However, chemical sunscreens allow UV light into the skin. In a chemical reaction, UV light is converted to heat and then dissipated from the skin by the sunscreen’s chemicals (the AAD lists oxybenzone, avobenzone, octisalate, octocrylene, homosalate, and octinoxate).

Is one type safer than the other?

The FDA, which regulates sunscreen products, has not declared either type unsafe. A new FDA rule to regulate sunscreen products sold in the US was proposed on February 21, 2019.

To comply with the proposed rule, the FDA is requesting more information on the safety of 12 active ingredients found in chemical sunscreens.

Four of these sunscreen chemicals (avobenzone, oxybenzone, octocrylene, and ecamsule) were found to be absorbed into the bloodstream at levels above 0.5 nanograms per milliliter (ng/mL) in a small randomized clinical trial published in JAMA in May 2019. That’s far more than the FDA requires for topical medications to be tested for toxicity.

The findings were confirmed in a follow-up study published in the JAMA Journal of the American Medical Association in January 2020. (avobenzone, oxybenzone, octocrylene, homosalate, octisalate, and octinoxate).

The study’s authors say their findings support more research but don’t prove sunscreen is harmful. Moreover, the known health risks of sun exposure outweigh the potential risks of sunscreen chemicals.

The Environmental Working Group (EWG) advises against using chemical sunscreens containing oxybenzone due to hormone disruption and allergic skin reactions.

Swimming in the ocean is also prohibited by Dr. MacGregor. One study found that common chemical sunscreen ingredients like oxybenzone may bleach and damage coral reefs. As a result, some tourist destinations, like Hawaii, have banned oxybenzone.

A May 2021 Nature Scientific Reports study found that methylene blue, a common laboratory dye, and medication, shows promise as an alternative sunscreen ingredient that blocks UVA and UVB rays while being environmentally friendly.

The FDA has approved zinc oxide and titanium oxide as ingredients in mineral sunscreens.

Chemical and Mineral Sunscreens: Pros & Cons

Cons of Chemical Sunscreen

Chemical sunscreens are easy to apply and do not leave a white film on the skin like mineral sunscreens. Dr. Ploch says chemical sunscreens also perform better in consumer tests that measure how long they protect skin from UV rays.

Disadvantages of Chemical Sunscreen

Some people have skin reactions to chemical sunscreens. Ploch says chemical sunscreens can irritate sensitive skin and exacerbate melasma and rosacea. This condition causes brown patches on the face, forearms, and neck, while rosacea causes red patches and pimples on the cheeks, nose, and forehead.

Using Mineral Sunscreen

The FDA only recognizes titanium dioxide and zinc oxide as safe and effective sunscreen ingredients. For those concerned about long-term chemical exposure, Ploch says mineral sunscreens are safer.

Mineral sunscreens are ideal for children, sensitive skin, and melasma patients. Chemical sunscreens’ heat dissipation can exacerbate melasma, says Ploch.

Unlike chemical sunscreens, which take 20-30 minutes to absorb, mineral sunscreens provide immediate protection. Mineral sunscreens can be worn over makeup or other skincare products.

The Drawbacks of Mineral SPF

Because mineral sunscreen is thick and sits on top of the skin, it may aggravate acne. For acne-prone or combination skin, Ploch recommends a mix of mineral and chemical ingredients. MacGregor suggests sunscreens with anti-acne ingredients like niacinamide (EltaMD 46 UV Clear is one option).

They are also harder to apply, leave a white film on the skin (from titanium dioxide and zinc oxide), and require more frequent application than chemical sunscreens, according to Ploch.

Still, mineral sunscreens have come a long way, and some options don’t leave a white cast. “Ask an expert and try a few,” MacGregor advises. EltaMD, Alastin, and Isdin.

The mineral is preferred, but anything is better than nothing.

Mineral sunscreens are the healthier option between the two. In contrast, Ploch says, mineral sunscreens are “like a healthy, home-cooked meal,” while chemical sunscreens are “like fast food.” Mineral sunscreens take longer to rub in and require more frequent application, but they may be safer over time.

No sunscreen is better than none. The FDA advises using a broad-spectrum sunscreen with SPF 15 or higher, reapplying every two hours.