The green group Friends of the Earth on Tuesday said legal loopholes in Europe bred worries about the impact of nanoscale compounds, used in the food industry, on health and the environment.
In a report presented to the press, Friends of the Earth Europe (FoEE) said it had identified "at least" 104 food or food-related products on sale in the EU that contained manufactured nanomaterials or were produced using nanotechnology and for which there was insufficient scrutiny under health and safety laws.
Internationally, several hundred nano-food products were likely to be on sale, it said.
Nanotechnology entails using materials on the scale of a nanometre, or a billionth of a metre.
Nanoparticles are being closely studied in fundamental research because of their potential in science and medicine -- for instance as new drugs for cancer.
But they are increasingly leaving the lab and entering the public domain, raising unresolved questions as to whether these novel materials are being vetted for safety, for workers in contact with them and people who use or consume them, FoEE said.
The group's nano-list included nutritional supplements, cling wrap and containers, antibacterial kitchenware, processed meats and chocolate drink.
"Europeans should not be exposed to potentially toxic materials in their food and food packaging until proper regulations are in place to ensure their safety," said Helen Holder, coordinator of the organisation's food and farming campaign.
"Policymakers must stop claiming that existing regulatory frameworks are adequate to deal with the emerging science of nanotechnology and address the gaps in current food safety legislation as soon as possible."
French scientists, speaking at a press conference in Paris last month, said the principal concerns over nanoparticles were about any effects on the lung, through inhalation, and of toxicity in the blood -- if for instance, sunscreen nanoparticles entered an open wound in the skin.