Potentially toxic chemicals are being incorporated into food, packaging, health supplements and other products by stealth, it is claimed.

Manufacturers boast that nanoparticles can deliver drugs or vitamins more effectively, kill harmful bugs in food or create self-cleaning windows.

But scientists, consumer groups and green campaigners fear the technology is being introduced into the diet, body and environment without proper safety checks.

Nanoparticles are 80,000 times thinner than a human hair - so small they can cross membranes protecting the brain or a baby in the womb.

Critics say it is not known how such tiny particles will interact with the body and organs in the long term, whether they are toxic or how long they will persist in the body.

Doom-mongers have warned that nanoparticles could mutate and reproduce out of control, consuming all life on earth, a scenario often referred to as "grey goo".

Yesterday a report by Friends of the Earth said current regulations are "ill-equipped" to deal with the unique properties of nanoparticles.

It said: "Despite concerns about the toxicity risks of nanomaterials, consumers are unknowingly ingesting them because regulators are struggling to keep pace with their rapidly expanding use."

The study found at least 104 food and agricultural products available in Europe, including the UK, which use nanotech particles or technology.

This includes some nutritional supplements under the Solgar brand, cling wrap and containers, antibacterial kitchenware, processed meats, chocolate drinks, baby food and chemicals used in agriculture.

Full article here.