There are two types of sunscreens:

Mineral physical blocks reflect ultraviolet rays from the sun and contain one of two active ingredients, zinc oxide or titanium dioxide.

Chemical sunscreen ingredients absorb the sun's ultraviolet rays. In the United States these typically include aminobenzoic acid, avobenzone, octisalate, octocrylene, and oxybenzone. None of these chemical sunscreens are approved for safety by the FDA.

According to the Centers for Disease Control and Prevention (CDC), skin cancer is the “most common type of cancer in the United States. Additionally, according to the Environmental Working Group, “the sun’s ultraviolet radiation is responsible for 80 percent of facial aging signs such as wrinkling, dryness, sagging and spotty pigmentation.” It is absolutely necessary to use sunscreen to help prevent cancer and premature signs of aging.

Normal aging and how you look is tied to your genetics, sleep patterns and your lifestyle choices. Too much sun exposure without effective SPF protection results in skin damage, or photoaging. Photoaging happens when ultraviolet light from the sun and/or tanning beds permanently damages the skin’s structure. To see the difference between normal chronological aging and photoaging, compare skin on an area of your body that is not exposed to the sun with skin that is constantly exposed to the sun like your hands, decollete, and your face.

Signs of photodamage begin in the teens to early twenties and include:

• Wrinkling
• Pigmentation changes such as age spots, liver spots and freckles
• Loss of skin tone (decreased elasticity)
• Rough, uneven skin texture
• Broken capillaries (spider veins), usually around the nose and chest
• Redness and blotchiness

Unlike mineral sunscreen ingredients, the main ingredients in chemical sunscreens can 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 in 2021, Hawaii banned the sale and distribution of sunscreens containing oxybenzone and octinoxate.

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

Oxybenzone is a common active ingredient in sunscreens. In 2019, the FDA said current data did not justify classifying oxybenzone as safe or effective, because the FDA test results had raised health concerns as oxybenzone has been found at high levels in human breast milk, amniotic fluid, urine and blood.

The FDA is currently researching oxybenzone's effect on allergic reactions, absorption through the skin and potential effects on hormone levels, reproduction and development.

The FDA notes children may be more vulnerable than adults from oxybenzone causing harm because of the potential for higher absorption and bioaccumulation.