Nanoparticles are defined by the US government as particles smaller than 100 nanometers. One nanometer (1nm) is 1 billionth of a meter, and a human hair, in comparison, is 80,000nm. By making minerals this size or smaller, some sunscreen manufacturers are able to make Zinc Oxide or Titanium Dioxide based sunscreen that is transparent on the skin. Nanoparticle based minerals are also used in mineral based makeup.

The problem with nanoparticles is that because of their small size and high ratio of surface area to volume, they can have chemical and physical properties very different from their larger counterparts. Nanoparticles are able to penetrate the deepest layers of skin and could possibly enter the brain and other internal organs where they could damage cells. Particles larger than 100nm (micronized particles or larger) are too large to penetrate the skin deep enough to enter the bloodstream and are subsequently much safer.

The FDA has not yet made a determination on the safety of nanoparticles, hence their use in beauty products continue. The term "micronized" has been often misleadingly used to advertize nano-sized particles, since the FDA has not set a definition for this term. Hence it is very important to verify the size of the particles being used in your beauty products.

Lavera products do not use nano-sized particles. Because of the grinding process, trace amounts of nano-sized particles may exist, but by and large, the Titanium Dioxide particles used in Lavera products are larger than 100nm. In addition, they are coated with stearic acid in order to render the particles inert. Hence, even if any TiO2 particles were to penetrate the blood stream, these particles would not be able to interact with human tissue.

There are concerns also with TiO2 particles being inhaled and entering the blood stream. All Lavera products including the sprays have TiO2 suspended in a lotion. The possibility of Titanium Dioxide particles escaping, becoming airborne and being inhaled is extremely low.

Lavera's mineral based sunscreens using Titanium Dioxide are safe for you and your family.

UPDATE:
As of June 2010, all Lavera sunscreens sold in the US and Canada now meet the EU's new UVA requirements. In order to meet these strict new regulations, all Lavera sunscreens bearing the UVA seal now contain coated zinc oxide particles. Typically, zinc oxide particles range in size between 30nm and 300nm. The majority of the particles are above >100nm.

While there has been a number of studies regarding the penetration of nanoparticles into the skin, with varying results, the Environmental Working Group (EWG) has written in their latest sunscreen guide: