The European Union's executive published a definition of nanomaterials on Tuesday, a move that will help regulators identify whether such ultra-fine particles -- whose risks are still largely unknown -- are present in food and consumer goods.
The definition will allow EU regulators to draw up a list of products that contain nanomaterials in order to carry out risk assessments, though products would remain on the market while analysis was carried out, one EU official said.
"These products could well be a threat or a benefit. This depends on a case by case basis," said Willem Penning, head of risk assessment at the European Commission's health and consumers department.
European consumer organization BEUC said products containing nanomaterials should be proven safe before being allowed onto the EU market.
"There is a knowledge gap, but for the moment people are being exposed to nano-products," said Monique Goyens, Director General of BEUC.
Nanoparticles behave differently to larger particles and can be easily inhaled through the lungs and enter the blood stream and blood cells, said Peter Gehr, a professor at the Institute of Anatomy at the University of Berne and head of a steering group on the opportunities and risks of nanomaterials.
Nanoparticles have been found inside human organs such as the brain, nose, lungs, skin and gastrointestinal tract, Gehr said, but their impact once inside these organs is not yet clear.
The Commission's definition of nanomaterials included particles between one and 100 nanometers in diameter. Around three hundred million particles each 100 nanometers wide could fit onto the head of a pin.
The particles have a variety of potential uses, for example creating foods with the same taste but lower fat, salt or sugar levels, or better packaging that keeps food fresher for longer and alerts consumers if the contents have gone off.
But experts have said manufacturers could be reluctant to use nanomaterials in their products, due to fears of a similar consumer backlash that greeted genetically modified foods in Europe.
"The goal of the industry, they do not want to poison their clients, this is very sure," Penning said.
But Goyens argued that companies have in the past said that their products are safe before scientific research later proved otherwise, citing examples such as asbestos.
"They (industry) want to maximize profits," she said.
Environmental campaigners complained that the Commission's definition was too narrow, and many products would avoid EU risk assessment as a result.
"The European Environmental Bureau is deeply disappointed by the Commission's decision to use a narrow definition for the term 'nanomaterial', indicating that industry lobbying has won over the Commission's own scientific advisors," the EEB said in a statement.