With the introduction of nanoparticle technology into sunscreen formulations, there are many green consumers who are hesitating on buying nano sunscreen due to suggested possible safety issues.

The cosmetic safety data base until recently held a grim view of nanotechnology, however even they have done a turn around now with nanotechnology. 

Nanotechnology is used in sunscreen to minimise the whitening effect that can be seen when you apply normal zinc and titanium dioxide.  The beaches in the seventies were reminiscent of zinc with the typical Australian having a coloured zinc applied across their cheeks for protection.

So why the desire for nanotechnology?

It allows the sunscreen to penetrate into the skin for effectively, and allows the correct amount of sunscreen to be applied without leaving the skin white.

Nanoparticles do penetrate the skin.  According to Professor Tilman Butz who led the “Nanoderm Project” at the University of Leipzig, the  problem is that Titanium dioxide and Zinc Oxide are poorly soluble, so once they penetrate into vital tissue and reach the blood vessels they can be transported to other organs.  Once they reach vital organs they can accumulate there.

There is enough information on inflammation being induced by nanoparticles accumulating in the lungs, so it could happen in the liver and other organs.

The Nanoderm Project looked at the penetration of Titanium Dioxide.  The findings where that in healthy human skin there is not penetration into vital tissue.  There is deep penetration into hair follicles but not into vital tissue.  So in this respect it is completely safe.

Professor Butz gave a word of warning though.  If you apply sunscreen on the skin it is not homogenously spread.  There are areas which are not covered.  You prevent the sunburn which is good but should not be fooled into thinking there is no damage.  So the message should remain to avoid excessive sun exposure.