New laws are needed to ensure that nanotechnology does not pose a future threat to human health, experts said today.

A Government-backed report from the Royal Society and Royal Academy of Engineering said the new science, which involves manipulating matter on ultra small scales, could bring enormous benefits.

But it recognised there could also be hazards, especially with microscopic dust particles or "nanotube" fibres that can be inhaled.

The report recommended that nanoparticles and nanotubes be treated as new chemicals under UK and European legislation to allow appropriate safety tests and labelling.

It also said nanotech materials should be approved - separately from chemicals in a larger form - by an independent scientific safety committee before they can be used in consumer products such as cosmetics.

One of the first of these materials, titanium dioxide nanoparticles, is already used in sunscreens.

The scientists urged companies to publish details of safety tests showing that they had taken account of the unusual properties of nanoparticles.

Professor Ann Dowling, who chaired the working group that produced the report, said: "There is a gap in the current regulation of nanoparticles. They have different properties from the same chemical in larger form, but currently their production does not trigger additional testing.

"It is important that the regulations are tightened up so that nanoparticles are assessed, both in terms of testing and labelling, as new chemicals."

As a precautionary measure, the report recommended that releases of nano materials to the environment should be minimised until their effects are better understood.

It said the Health and Safety Executive should review existing regulations and consider setting lower exposure levels for manufactured nanoparticles to protect workers in university laboratories and other potentially hazardous environments.

Nanotechnology involves the study and manipulation of matter at the scale of the nanometre - a billionth of a metre, or a millionth of a millimetre. A normal human hair is about 80,000 nanometres wide.

Although nanoparticles have been known about for centuries, equipment capable of manipulating them has only recently become available.

Revolutionise

Nanotechnology could potentially revolutionise medicine, engineering, chemistry and computing. It could be used to deliver cancer-fighting drugs, develop faster computers, and create "smart" materials such as self-cleaning glass.

But some, notably the Prince of Wales, have warned that without proper safeguards it may also pose a threat.

The Prince was widely criticised earlier this moth for saying the irresponsible meddling with nanotechnology could cause another thalidomide-type disaster.

Scientists emphasise that nanotechnology is not a sinister force but a natural evolution from physics and chemistry.

Prime Minister Tony Blair has personally backed scientists working on advances in nanotechnology.

But in light of public concern, the Government commissioned the Royal Society and the Royal Academy of Engineering to carry out an independent study of developments in the field in June last year.

Their remits included an analysis of whether nanotechnology raised, or was likely to raise, new ethical health and safety or social issues.

Brendan Barber, TUC General Secretary, said: éThis isnét an apocalyptic warning about énano-gooé or renegade énano-robotsé but a genuine concern for the safety of staff breathing in and absorbing tiny, toxic particles.

éAsbestos is still killing people 100 years on. We must learn from this tragedy and ensure that a regulated nanotechnology industry can make products that are useful and innovative but safe to workers and consumers.é