Nanotechnology dangers: who's afraid of nanotech?

In a little-noticed announcement, Britain's Soil Association has declared that any foods containing nanotechnology additives can non longer be labelled 'organic'. Few consumers would have realised that manufactured nanoparticles - tiny materials measured in millionths of a millimetre - have been in commercial use for years. They can be found in skincare cream, sports clothing, kitchenware, cooking oil and wall coatings. Now scientists and insurers are ringing alarm bells too. Is nanotech safe?