Ask the Doc: Nanomaterials and Your Skin

Q: What are nanomaterials and are they safe in sunscreen?

Nanomaterials, or more general, nano technology, is the science that investigates and manipulates materials at the size rate between one and one hundred nano meters. Well what does that mean? Think of a single hair strand. A single hair is on the broader of 10 to 1000 nanometers in dynameters.  Cells, cellular organelles, even bacteria are huge on this scale. In fact, even the smallest viruses, such as the adenovirus, are on the broader of 150 nanometers: even beyond the spectrum. If that doesn’t convince you, Lebron James is two billion nanometers in height and that is a lot of nano. So what is the big or little deal here? At this size, materials behave differently.  As the size of material decreases its surface area relative to volume exponentially increases. What does this mean? There is more surface to go around. This means this surface can easily interact with biological processes or features such as the skin or other organs. Now, the question has come up: are these materials safe? This is a general statement. Nanomaterials encompasses many, many different things. The FDA has recently released draft guidelines approaching this issue, such as: how do we determine if these are safe?  Cosmetic companies typically use these materials for many of their benefits- such as making sunscreens invisible or giving something that usually feels kind of icky a little more cosmetic appeal. They don’t have to state that these have nano materials in them. The FDA is approaching this so everyone feels safe with the products.