Are chemical sunscreens bad for reefs?
Certain kinds of sunscreen react with the rays of the sun when they come into contact with water to create hydrogen peroxide, which is toxic to aquatic plants, like phytoplankton and coral reefs, that provide essential nutrition to marine animals like small fish, dolphins, and whales.
Oxybenzone is one of the 10 sunscreen chemical ingredients responsible for damaging the DNA of corals, bleaching corals, and disrupting coral reproduction.
Are nanoparticles safe in sunscreen?
According to the Environmental Working Group, mineral sunscreens containing zinc oxide and titanium dioxide provide strong sun protection since they don’t readily break down in the sun, and they’re associated with very few health concerns.
But nano-sized versions of these minerals is a different story. While studies show no evidence that nanoparticles cross the skin in large amounts, inhaling or ingesting them can cause lung and gastrointestinal damage.
And nanotechnology in sunscreen isn’t good for coral reefs, either. Nanotechnology involves breaking down and manipulating the particles in these minerals at a molecular and atomic level. While nanoparticles absorb into the skin without leaving white residue behind — which is why consumers like nano mineral sunscreens — they accumulate in coral reef ecosystems and cause damage just like their chemical counterparts.
Does mineral sunscreen expire?
The FDA requires that all sunscreens remain fully effective for three years. Mineral sunscreens are more stable than chemical sunscreens and usually have a longer shelf life. If you store it in a cool, dark place it will last as long as possible.