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.
As someone with the skin complexion of a jar of mayonnaise, burns after ten minutes on a cloudy day, and got sun burned to the point of sun poisoning and second degree burns once in my youth - yeah, I’m going to chase that bigger number. Skin cancer also runs in my family. Once had a dermatologist tell me that I shouldn’t go out of the house without a minimum of spf 50 on all exposed skin, period. Doesn’t matter the time of year. I don’t tan. I freckle and more freckles mean more checking for the ABCs of skin cancer. Just had an age spot (according to the dermatologist) removed not too long ago because the freckle became raised, rough, and irregularly shaped.
For someone like you I totally understand. Getting sunburned after 15 minutes of cloudy weather is extreme. My condolences.