The more I read up on sunscreen (since it’s now summer), the more frequent the word nanotechnology, aka nanotech, pops up. I know my entry-level knowledge about sunscreen doesn’t grant me any right to discuss this topic, so I did a little bit of research to familiarize myself with it. Below are my findings.
In most physical sunscreens, zinc oxide and titanium dioxide are used to give broad spectrum protection against UVA and UVB. These two ingredients are stable, hypoallergenic, and pretty safe for most people. The disadvantage, however, is that both ingredients can leave a white cast on the skin. And that can be a great turnoff for consumers. To improve the finish of these sunscreens, manufacturers use nanotech to micronize the particles of zinc oxide and titanium dioxide. So when sunscreen is applied, it can become translucent on your skin. However, this is also where the problem arises.
Potential Risks of Nanotech
Many suspect, when ingredients are broken down to nano size, they may not be as safe to use on our skin. Studies (source: Friends of the Earth Australia) have shown that nano forms of zinc oxide and titanium dioxide used in sunscreen can produce free radicals, damage DNA, and cause cell toxicity. And when nano forms of titanium dioxide are inhaled or injected into animals’ blood stream, the particles can cross the placenta and enter developing embryos. But note, these are tube test studies and animal tests only.
No Evidence = Safe?
On the other hand, when I tried to locate any evidence to prove that it’s potentially dangerous to use nano-sized ingredients on intact skin, I can’t find any (if you have found any, please let me know). In fact, the result from my research yields the polar opposite: animal tests done by FDA don’t show evidence that sunscreens with micronized zinc oxide and titanium dioxide pose a threat. Another source from Cancer Council Australia also shows similar result.
However, the fact that hard and solid evidence is lacking doesn’t mean it’s safe to use nanotech sunscreen. I’m not the paranoid type, but I see no point in taking the risk if there are so many people who claim there is a threat in using it. So, whenever possible, I dodge it. The problem is, if a company doesn’t choose to disclose such information, we would have no way to know which sunscreen has nano particles. In such case, you may want to take a look at this nano-free sunscreen list before shopping.