Are Sunscreens with Nanoparticles of Zinc Oxide Safe?
Products using nanotechology and materials has become more and more common. Zinc oxide (ZnO) and titanium dioxide (TiO2) are used in nanoparticle size in sunscreens. They provide physical blocks from the harmful UVA and UVB rays, protecting the skin from photo-damage which is known to cause skin cancers.
One nanometer (nm) is roughly 100,000 times smaller than a human hair. The physical and chemical properties of nanoscale materials, such as reactivity, persistence, or bioavailability, can differ significantly from their larger scale counterparts. This is the concern of the group Friends of the Earth who feel that sunscreens with nanoparticles are a risk to your health and urge you not to use them.
Zinc oxide and titanium dioxide nanoparticles used in sunscreens range in the 20 – 30 nm size. Their use in sunscreen has become popular as the nanoparticles appear transparent when applied to the skin rather than an opaque white cover. This transparency makes the sunscreen much more cosmetically acceptable than the larger-particle ZnO and TiO2 use.