Titanium Dioxide and Zinc Oxide are considered two of the best ingredients used in sunscreens because they offer protection from both UVA and UVB rays. But, because they leave a white cast on skin, a lot of people tend to avoid products that contain them. For this reason, manufacturers have started using very small particles of Titanium Dioxide and Zinc Oxide that protect skin from UV rays without the white color.
Concerns about nanotechnology
However, there is a controversy about nanotechnology used in sunscreens. Studies have shown that nanoparticles can produce free radicals which can damage DNA cells. But for that to happen, these particles have to penetrate past the outer dead layers of the skin into the living cells.
Nanoparticles can’t penetrate skin
Although further studies need to be done, current research shows that these small particles remain on the surface and can’t reach the living cells. In addition, studies also show that adding antioxidants to a sunscreen eliminates the risks of Titanium Dioxide nanoparticles causing free radical damage.
Concerns about inhalation of nanoparticles
While topical application is considered safe, inhalation remains a concern. Studies have shown that nanoparticles can damage animal lungs if inhaled so, until further research on their safety (or lack of) is done, I think that avoiding sunscreens in powdered or spray form may be a good idea.
It’s up to you to decide if you want to use sunscreens that contain nanoparticles or not. In any case, not using sunscreens at all or using sunscreens that don’t offer adequate protection causes far worse damage.