By Jonathan Fildes
BBC News science and technology reporter
Industry should disclose how it tests products containing nanoparticles, the Royal Society of the UK has said.
Carbon nanotubes are a basic building block of nanotechnology
Public information was needed because of uncertainties over the safety of some products that contained particles engineered at small scales, it added.
A new inventory of consumer goods lists over 200 items that are already available and contain nanotechnology.
Enta (European Nanotechnology Trade Alliance) responded by saying that safety was its top priority.
"There are strict regulations to check that products are safe and suitable for the public to use and our members follow these," Del Stark, the chief executive of Enta told the BBC News website.
"The members of Enta are committed to developing new nanotechnologies in a safe and responsible manner and are working closely with the government to ensure this."
In 2004, the Royal Society and the Royal Academy of Engineering published a report that urged tighter controls in Europe and the UK on some aspects of the industry.
In particular it highlighted the potential risk of "free" nanoparticles that might escape to the atmosphere and have an effect on health.
Particles on this scale already exist in the air - produced by the burning of fossil fuels and by volcanic eruptions, for example; but scientists are now able to engineer materials at these tiny sizes to give them specific, useful properties.
For example, "free" nanoparticles are used in cosmetics and in some food supplements.
Some studies show carbon nanotubes have a toxic effect
"This is one particular area where there is some uncertainty about safety," said Professor Ann Dowling, chair of the report.
The Royal Society statement was made in the same week that a leading UK researcher also said there had been a failure to act on the recommendations of the royal societies' report.
Professor Anthony Seaton of the University of Aberdeen told a conference that specific questions raised in the report about nanoparticle toxicity and how to measure it in the workplace had still not been adequately answered.
"There is very little evidence that anyone has put any thought or money into answering these questions," he told the conference.
But Enta believes that the perception that industry is dragging its feet is wrong.
"I don't think that it is anything to do with industry not being interested or government not being interested," said Mr Stark.
Instead, Mr Stark believes that both are waiting for a new European law known as Reach (Registration, Evaluation and Authorisation of Chemicals) to be passed.
The law has been described as the most important EU legislation for 20 years and puts the onus on businesses to show that the chemicals they use are safe.
It will also start to address the lack of standardised tests for assessing the toxicity of nanomaterials in some industries.
Currently standards vary depending on which industry regulations a product falls under or how the tests are done.
A recent paper in the journal Nano Letters reported that experiments done to assess the risk of inhaling carbon nantotubes, a common manufactured nanoparticle, sometimes showed strong toxic effects and sometimes did not, depending on which methods were used.
"Once [Reach] has been agreed, we will move forward," Mr Stark said.
Professor Seaton made his remarks during the Nanoparticles for European Industry conference in London.
The event allows nanotechnology companies to showcase new ways of fabricating the tiny particles and to discuss how laboratory processes can be scaled up for manufacturing consumer products.
During his address he also warned that "very little" was still known about the health impacts of nanoparticles engineered at small scales and that industry should take his comments as a "warning shot". He said his concern covered lab workers as well as consumers.
Businesses countered his remarks by saying there are already strict safety regulations.
"It's not like nanotechnology is appearing totally out of the blue in a completely non-regulated framework," said Dr Paul Reip, interim spokesperson for the Nanotechnology Industry Association (NIA) and founder of Qinetiq Nanomaterials.
"We're as concerned as anybody else about the safety of our colleagues, workers and the products that we sell," he said.
However, some researchers are worried that because nanotechnology is used in products from many different industries - including cosmetics, chemical and electronics - there is no coherent regulatory framework.
Others are bothered that regulators are not able to assess the risk of nanoproducts properly as the properties of materials are known to change at the nanoscale.
To address some of these concerns, the Department for Environment, Food and Rural Affairs (Defra) is in the process of extending its regulatory framework to take account of the unique properties of many nanomaterials.
It is talking to industry to find a way to set up a voluntary scheme for reporting test results.
Groups like Enta say this demonstrates the industry's commitment to transparency.
The production of nanoparticles is just one branch of nanotechnology that involves the manipulation of molecules, and even atoms, to make new materials.
Manufactured nanoparticles are dust-like fragments with diameters of less than 100 nanometres (billionths of a metre) - one thousandth the width of a human hair.
Nanoparticles made from metals, alloys and ceramics are already used in many products, including sunscreens, paints and sticking plasters.
A new web inventory of consumer products lists 231 products that purport to contain nanotechnology, showing how the tiny science is increasingly becoming an everyday part of our lives.
Most nanotechnology poses no known risk to humans but some researchers question whether nanoparticles may be different, because they are known to be able to cross over into areas of the body that larger particulates, which humans are exposed to every day, cannot reach.
Like the Royal Society, Professor Seaton is concerned about the risk posed by inhaling the particles.
In his speech, he drew a parallel with the history of asbestos and the disease asbestosis.
"It was known as a wonder material and it got into thousands and thousands of applications," he said. "Now, thousands and thousands of people are dying from it."
Any long-term damaging effects of nanoparticles are unknown.
Frederic Luizi, research and development director for carbon nanotube producer Nanocyl, rejected the notion that asbestos and the many varieties of nanoparticle were like for like.
"They are different and they should be considered differently," he said.
Many producers of nanoparticles encapsulate them in polymers or liquids to reduce the risk of inhalation during industrial processes, and most of those used in consumer products are incorporated into composite materials that prevent their escape.
Products like cosmetics are the exception.
Dr Luizi argued that industry was actually taking a very cautious approach. This was necessary, he said, because it had to anticipate the demands of the legislation like Reach and because it could not afford to gamble on a market that some analysts expect to be worth one trillion dollars by 2015.
"Any single incident could jeopardise the whole future of the industry," he said. "We just cannot take any risks."
SOME POTENTIAL USES OF NANOTECHNOLOGIES
1 - Organic Light Emitting Diodes (OLEDs) for displays
2 - Photovoltaic film that converts light into electricity
3 - Scratch-proof coated windows that clean themselves with UV
4 - Fabrics coated to resist stains and control temperature
5 - Intelligent clothing measures pulse and respiration
6 - Bucky-tubeframe is light but very strong
7 - Hip-joint made from biocompatible materials
8 - Nano-particle paint to prevent corrosion
9 - Thermo-chromic glass to regulate light
10 - Magnetic layers for compact data memory
11 - Carbon nanotube fuel cells to power electronics and vehicles
12 - Nano-engineered cochlear implant