Products with a very high UV protection can be produced only if nano pigments are included as ingredients.

Various scientific studies have come to the conclusion that under certain conditions, the materials can damage human DNA, according to Germany's union for environmental protection.

'However, to our knowledge nano materials that are currently in products on the market applied to healthy skin result in no direct danger to consumers,' said Mario Goetz of Germany's federal institute for risk assessment in Berlin. He added that the new decree strengthens consumer protection.

Germany's union for environmental protection views the regulations as a step in the right direction. However, the regulations are not yet technically advanced enough to deal with the continued adoption of nano materials.

'The definition of nano materials in the EU decree is in our opinion too narrowly conceived,' said Katja Faupel of the union. What is still lacking is a worldwide uniform definition of the term nano materials.

The union thinks the definition should be broadened to include degradable and soluble materials.

'Otherwise a lot of nano materials could be used without the appropriate label,' said Faupel, adding that she believes the regulations will soon be revised.

Critics also complain about the long transition phase: The new decree takes affect in 2012. Until then, nano materials may continue to be used without labelling. A consumer who would like to know whether a product contains nano materials has only one way of finding out: Call the maker of the product and ask.