When you think of zinc sunscreen, the first thing that likely pops into your head might be that classic image of a lifeguard in red swimming trunks with a big glob of white paste on his nose. Attractive, right? Thankfully, we’ve since figured out a way to reap all of the sun protection benefits of zinc oxide without having to look like we’ve had an unfortunate run-in with some diaper cream.
So how is it possible to have the best of both worlds, you ask? The answer: microparticles.
What Is a Microparticle?
Like the name suggests, a microparticle, sometimes also referred to as a nanoparticle, is simply smaller in size than their non-micronized counterparts. In the case of zinc oxide, microparticles are more cosmetically-pleasing because they don’t appear white when applied to your skin, like the zinc oxide formulas of the past, which contained larger, non-nano particles.
There are two primary ways to micronize a particle. For the first process, you can think of a particle of zinc oxide as a rock. To make it smaller, you can grind it down until it becomes a fine sand. The result has the exact same components as the original particle, just in a smaller package (Oriental Journal of Chemistry).
The second way to create a microparticle is more of a bottom-up approach. Using a reducing agent to trigger a chemical reaction, it’s possible to actually rearrange single atoms into groups of nanoparticles, while, again, maintaining the function of the particle itself (Oriental Journal of Chemistry).
Are They Safe?
When it comes to the safety of using microparticles in sunscreen, two camps of thinking seem to have developed. On one side, an argument exists that microparticles are so small that they can penetrate your skin. This would be ineffective at creating a physical barrier to reflect UV rays and render them harmless.
However, despite these safety concerns from some of these well-meaning persons, micronized zinc oxide should not penetrate the epidermis, no matter how small the particles are. The vast majority of formulas are designed with occlusive agents and silicones that prevent the penetration of particles into the skin. Therefore, these particles will still protect you from the sun by remaining on the surface and preventing the absorption of harmful UV rays (The Cancer Council of Australia).
Alternatively, larger zinc oxide particles don’t actually provide more UV protection. It may seem this way because you have a telltale shield of white-looking cream all over your face, but that’s just appearances. In theory, larger zinc oxide particles would not be able to cover as evenly as micronized particles. I believe that micronized zinc oxide particles actually provide better protection, as they can fill in the face more evenly by getting into tiny crevices, thus providing better UV protection overall.
The Bottom Line
When it comes to sunscreen, I can’t stress enough how central it is to keeping your skin healthy, glowing, and youthful. Finding (and using!) the perfect daily sunscreen is one of the best things you can do for your health, and the truth is that many of the most effective formulas are now using zinc dioxide microparticles to provide the best combination of UV protection and a sheer, invisible appearance. Gone are the days of choosing between a white nose and a red, painful sunburn. From my personal experience and research, microparticles in sunscreen deliver safe and efficient (and, not to mention, clear) UV-blocking capabilities.