Most people don't wear enough sunscreen, and what they do wear is often washed away by sweat, salt water, or a dip in the pool. The best sunscreen is the one you choose every day, because wearing any is better than wearing none.
Mineral Sunscreens For Everyday Outdoor Wear: Why You Should Worry About What's in Your Sunscreen
Sunscreens with mineral (a.k.a. physical) blockers are less likely to contain potentially harmful chemicals - though some may still combine chemical ingredients with the minerals titanium dioxide or zinc oxide. Even those combinations are safer bets than chemical-only sunscreens containing oxybenzone and octinoxate, which have been shown to harm aquatic ecosystems and coral reefs.
In February 2019, the FDA published a proposed rule on sunscreen active ingredients, noting that there was insufficient safety and efficacy data to classify 12 commonly used chemical active ingredients, including oxybenzone, as generally recognized as safe and effective (GRASE). Consider switching to a mineral sunscreen - even if you're satisfied with your current product.
Oxybenzone and octinoxate, two chemicals widely used in sunscreen, have been linked to coral bleaching and death. Hawaii became the first U.S. state to ban the sale of sunscreens containing oxybenzone and octinoxate in 2018, and that law went into effect on January 1, 2021. Even if you don't live anywhere near a reef, we recommend avoiding sunscreens with those ingredients.
How Chemical Sunscreens Harm the Environment
UV filters in sunscreens are an emerging contaminant of possible concern for aquatic environments. Studies have identified UV filters such as oxybenzone - octocrylene, octinoxate, and ethylhexyl salicylate in almost all water sources around the world, where they have been found to persist and bioaccumulate in the food chain. In laboratory settings, oxybenzone has been implicated specifically as a possible contributor to coral reef bleaching.
Certain chemicals used in sunscreens can potentially persist and accumulate in aquatic ecosystems. Concentrations of oxybenzone measured in some coastal waters exceeded guidelines established by the EPA for the protection of aquatic life. UV filters can enter the environment through wastewater or when washed off during recreational activities.
The good news - however, is that you can find effective sunscreen that won't harm sensitive marine environments. Look for products that use mineral UV blockers such as zinc oxide or titanium dioxide. Unlike their chemical counterparts, these minerals physically block UVA and UVB rays without absorbing them, much like the way chalk reflects light.
Are Nanoparticles in Mineral Sunscreens a Health Concern
Titanium dioxide (TiO2) and zinc oxide (ZnO) minerals are frequently employed in sunscreens as inorganic physical sun blockers. Microsized TiO2 and ZnO have been increasingly replaced by TiO2 and ZnO nanoparticles (NPs) (<100 nm) to avoid the cosmetic drawback of opaque sunscreens. When applied to the skin, most NP-containing sunscreens form a thin continuous film on the surface of the stratum corneum. This creates a strong mechanical barrier that prevents the penetration of NPs into living parts of the skin.
Skin exposure to NP-containing sunscreens leads to incorporation of TiO2 and ZnO NPs in the stratum corneum. Although it has been suggested that ZnO and TiO2 NPs have the potential to penetrate the skin and induce adverse effects - most studies demonstrate that NPs remain on the surface of the skin. At present, there's no convincing evidence that NPs used in sunscreens pose a significant risk to human health.
Choosing Mineral Sunscreens for Everyday Outdoor Wear
The American Academy of Dermatology advises choosing a sunscreen that advertises a sun protection factor (SPF) of 30 or higher. We recommend sunscreen with SPF 30-50, reapplying at least every 2 hours, no matter the SPF level. As with most sunscreens, the ones we recommend should be reapplied every two hours to meet their promised effectiveness.
People wear about half as much sunscreen as they should - and rubbing it in vigorously instead of gently can decrease the protection it offers, its sun protection factor (SPF), by up to a fifth. If trends continue as they're, cases of melanoma are expected to increase by 50 percent by 2040. Just remember: Any sunscreen is better than no sunscreen.
Sunscreens with broad-spectrum protection that contain titanium dioxide or zinc oxide - two minerals that form a protective film on the skin - tend to be safer bets than chemical sunscreens, which use ingredients such as oxybenzone that may disrupt hormones or damage the environment. Even those combinations are safer bets than chemical-only sunscreens containing oxybenzone and octinoxate - which have been shown to harm aquatic ecosystems and coral reefs.
References
- oxybenzone has been implicated specifically - hero.epa.gov
- enter the environment through wastewater - epa.gov
- and ZnO have been increasingly - pmc.ncbi.nlm.nih.gov
- 50 percent - wired.com
