These creams have some chemical that blocks the UV with some capacity, say a factor of 50. Why can’t I apply two layers of this cream to now get a 100 factor equivalent protection?

I asked the chemist at the store and they said it’s not how it works and that the highest protection factor they have is 75 (which was super expensive).

What gives?

Edit: Thank you for those super informative answers.

  • jaschen306@sh.itjust.works
    0·
    6 days ago

    Don’t buy American sun screen. It’s always cakey and flakey. Go import some Korean sunscreen. It’s basically feels like you have nothing on and gives you better protection.

    • lietuva@lemmy.world
      0·
      6 days ago

      Us has 16 of uv filters aproved, whereas EU has 30+. Last UV filter aproved by FDA was in 1999. So us had old sun screens

    • ickplant@lemmy.world
      0·
      6 days ago

      There are plenty of great brands of American sunscreen. Just don’t buy the super cheap shit. Which is generally good advice in any country. Some brands that come to mind are Kiehl’s, First Aid Beauty, and EltaMD. To be clear, I love me some Korean skincare, and I think it’s superior to American. I just don’t agree with your premise that all American sunscreen is “cakey and flakey.”

      • jaschen306@sh.itjust.works
        0·
        6 days ago

        I just looked it up and America will soon get the good sunscreens. Bemotrizinol has just been FDA approved.

        Until then, I am sticking with American has some bad sunscreens. Until I guess this month.