This is a great instructable! I'm looking at making my own as I am allergic to almost all commercial sunscreens. I was wondering if you know/have any advice about whether a silicone base would work? I use 100% silicone as a moisturiser because it's one of the only things I have found that doesn't irritate my skin. I can't see any reason it wouldn't work as a base and I know that it is in some comercial sunscreens already but I thought I'd see what you have to say about it anyway because you seem to be in the know. I think one of the best things about using silicone as a base would be that you could easily see if the active ingredient is incorporated properly because it starts clear and would become cloudy with the addition of the zinc. I would also expect it to last longer than other bases being a polymer which would be very unlikely to harbour and feed bacteria or other nasties.



I also wanted to point out that in my research I've found that powder screens are somewhat dangerous because of the likelihood of inhalation. I originally planed to make a powder because it seemed easier and I hate the feeling of putting on greasy sunscreen in the middle of summer but have decided against that because of this health risk.



Thanks for your time, eagerly awaiting a reply :)