Silk Naturals

Can I add this to my moisturizer and get some sun protection? I found this piece below but I'm not a cosmetic chemist!

Zinc Oxides: Which One is Right for You?
Regular zinc oxide has a particle size of >200 nm (nanometer), a visible whitening effect on the skin, is water dispersible, gives great coverage in makeup products and lip balms, and offers good protection in baby care products.
Micronized zinc oxide has a particle size of <200nm (mean 86nm), has a minimal whitening effect on the skin, is water dispersible, offers superior sun protection but does not offer coverage in makeup products.

If you were to try it (small batches, again) I would not rely on it as your sole source of sun protection. It is not tested and recommended for such an application on its own. I am sorry that I can't make recommendations beyond this.

I think I remember hearing something about not mixing physical and chemical sunscreens. So if your moisturizer has any SPF to it already and it chemical (not zinc oxide or titanium dioxide) then you probably should not. I think they just void each other out and so neither provides sun protection when mixed together. I'm not 100% sure though, I just remember hearing something to that effect.

Is there a reason you shouldn't mix physical and chemical sunscreens?Tons of sunblocks have both in them...

missyjean wrote:Is there a reason you shouldn't mix physical and chemical sunscreens?Tons of sunblocks have both in them...

I have not found any primary sources of this information. But the general info out there is that uncoated titanium dioxide and zinc oxide make the chemical sunscreen ingredient avobenzone degrade much faster in light.

I can't say that the avobenzone cancels out the mineral sunscreen qualities, but most sources I read (again, none were primary sources of the information) indicated that mineral ingredients did affect avobenzone. And avobenzone is probably the most common ingredient in chemical sunscreens in the US.