Why do you need to wait 30 minutes after applying a chemical sunscreen? Author: Published: 0 comments Learn what is really real, in an industry full of fake › Forums › Ask the Beauty Brains › Why do you need to wait 30 minutes after applying a chemical sunscreen? This topic is empty. Viewing 2 posts - 1 through 2 (of 2 total) Author Posts March 23, 2016 at 7:29 pm #92447 AnonymousGuest Why do you need to wait 30 minutes after applying a chemical sunscreen before going out in the sun? Do the chemicals in the sunscreen need to react with the skin? March 24, 2016 at 8:33 pm #95695 RandySMember Read/listen to this: Why do I have to wait for sunscreen to work? Episode 19 Author Posts Viewing 2 posts - 1 through 2 (of 2 total) The forum ‘Ask the Beauty Brains’ is closed to new topics and replies.