Sunscreens made with zinc oxide and titanium dioxide generally score well in EWG’s ratings because:
They provide strong sun protection with few health concerns. They don’t break down in the sun. Zinc oxide offers good protection from UVA rays. Titanium oxide’s protection isn’t as strong, but it’s better than most other active ingredients.
Nanoparticles in American sunscreens are either titanium dioxide or zinc oxide.
Zinc oxide is EWG’s first choice for sun protection. It is stable in sunlight and can provide greater protection from UVA rays than titanium oxide or any other sunscreen chemical approved in the U.S… Years ago, zinc oxide sunscreens, often seen on lifeguards’ noses, were famously white and chalky. Today, sunscreen makers use zinc oxide nanoparticles to formulate lotions with less white tint.