Nanoparticles in sunscreens.
The topic of nanoparticles in personal care continues to heat up. Firstly nanoparticles or nanomaterials are particles of extremely small size with the purpose to improve their intended applications. One nanometer (nm) is one-thousandth of a micrometer (m), one-millionth of a millimeter (mm) and one billionth of a meter (m). To put that size in perspective, 1 nanometer is roughly 100,000 times smaller than the width of a human hair.
One of the obvious concerns with regards to nanomaterials in personal care products is that their size allows them to penetrate the skin and enter into the bloodstream accessing organs and tissues. To compound this concern, there are virtually no studies that indicate the safety of these materials once they enter the body.
In the case of sunscreens, using physical reflective block UV filters like titanium dioxide and zinc oxide creates a white caking or heavy feel on the skin. With these ingredients now available as nanoparticles, the lotion can be a more smooth and silky feeling. Zinc Oxide is often referred to as a natural mineral present in the earth’s crust however, most zinc oxide used commercially is produced synthetically. The other misleading claim for nanoparticle zinc oxide and titanium dioxide was that they were more effective in their ability to block UV rays than their counterparts, a claim that has been proven not be true.
With relation to nanoparticles in sunscreens, it would appear the risks far outweighing the benefits. I believe that environmental and public interest groups are wise to demand government and industry complete testing and approval of nano-containing products before commercialization, not just for human health but also for their environmental impact.