As my research on sunscreens continue I have decided that I will be using zinc oxide as the physical sunblock in my future formula.
The next step is figuring out what type of zinc oxide I will be using, with or without nanoparticles?
What are nanoparticles?
Nanoparticles are routinely defined as particles with sizes between about 1 and 100 nm that show properties that are not found in bulk samples of the same material.
Basically a nanoparticle of zinc oxide is a very minuscule size zinc oxide.
Why would you want nanoparticles of zinc oxide?
Zinc oxide is good physical sunblock, but it can leave behind a white residue that rests on the skin. Once zinc oxide is in a nanoparticle size the sunblock can go on more clearly. Nanoparticles are used in many mineral foundations and sunscreens because it makes the appearance of zinc oxide more appealing to the user.
Why might this concern you?
The science of nanoparticles is still in its infancy of study. Since it is fairly new there is no longitudinal studies done. There is also concern for what a nanoparticle has the potential to do to the body.
NP [nanoparticles] have greater potential to travel through the organism than other materials or larger particles. The various interactions of NP with fluids, cells, and tissues need to be considered, starting at the portal of entry and then via a range of possible pathways towards target organs. The potential for significant biological response at each of these sites requires investigation.
Since there is controversy on nanopartcles I am going to stay away from using it in my sunscreen. I plan on using a non-nano zinc oxide, just to be safe.
Extra resources for nanoparticle studies: