Nanoparticles, which are 80 times thinner than a human hair, are used by firms including Boots, The Body Shop, Avon, Nivea and Unilever, especially for UV filters in sunscreens.
Some manufacturers believe the technology can deliver the benefits of products in a more effective way.
But critics say the size of the particles may allow them to permeate protective barriers in the body, such as those surrounding the brain or a developing baby in the womb.
Their scale also changes the way they interact with other cells, which might lead to unforeseen toxic effects.
con't @
http://www.telegraph.co.uk/news/newstopics/politics/health/3384114/Nanoparticle-cosmetic-creams-safety-warning.html
...also being used in some paints.n Low VOC's or in some cases none at all.
Some will even kill bacteria
Another great reason to avoid sunscreen... I refuse to wear it, anyway. If I need sunscreen, I wear a hat and a longsleeve shirt. They work great and I don't get all slimy.