How is it that some physical sunscreens having eg. 10% zinc oxide & 7% titanium dioxide are SPF 50, while others having eg. 19% zinc oxide & 4% titanium dioxide, are SPF 35 or lower? 2.74K viewsNovember 30, -0001 0 Question68.06K May 29, 2019 1 Comment Shouldn’t the higher concentration of sunscreen actives have a higher SPF level? How does this work? In: Chemistry Afinkawan commented May 29, 2019 Only if the active stays put on your skin. The rest of the formula is just as important. If it absorbs into your skin a different way then it may not last as long or reflect a different amount of UV light or protect a different depth of skin. 0 Answers ActiveVotedNewestOldest Register or Login
Only if the active stays put on your skin.
The rest of the formula is just as important. If it absorbs into your skin a different way then it may not last as long or reflect a different amount of UV light or protect a different depth of skin.