What you need to know about nanotechnologiesWhy do I need to know?

Nanoparticles occur naturally in things like forest fires and volcanoes, and can also be manufactured unintentionally, in car emissions for instance.

However, when we deliberately manipulate materials at this very small scale, we don’t yet fully understand the impact of doing so.

The risk of the unknown

Some nanomaterials could have harmful properties. We don’t know enough about how the materials behave at such a small scale and nanoscience experts, such as The Royal Society and The Royal Academy of Engineering, fear certain nanoparticles may hide unforeseen side effects.

Most concerns involve the manufactured ‘free nanoparticles’, such as those found in foods and cosmetics, and their potential to interact with the body or the environment rather than fixed nanoparticles like those found in computers and phones.

Some of the potential dangers include:

1 Concerns around toxicity

Some engineered nanoparticles might be more toxic than larger versions. Their increased surface area makes them more reactive and they may be able to penetrate tissues and cells more easily than larger particles. Pre-existing health conditions (such as asthma and heart disease) could worsen as a result of very small particles damaging cells and causing inflammation.

Very little is known about the ability of nanoparticles to move around the body, to accumulate, be excreted or their potential to cause toxic effects in organs. Another problem is that many of us are exposed to a combination of nanotech products but all current testing focuses only on individual exposures.

Legally, consumer products have to be safe to go on the market. However, experts are still struggling to work out how to assess what is safe when in the nano form. It can't be assumed that a chemical in a nano form will behave in the same way as it does in its larger form.

2 More easily absorbed

A 2008 study, for example, looked into concerns that some free carbon nanotubes, used in products such as sports equipment could penetrate deeply into the lungs. It found that longer carbon nanotubes could be as harmful as asbestos and therefore need to be properly controlled.

This doesn't mean that all nanomaterials are unsafe, but it does highlight the urgent need for a better understanding of the risks so that they can be managed. The speed of change is quicker than our understanding of potential risks. So far, research has focused on relatively benign substances such as carbon, but manufacturers are using materials that may be more toxic, such as the salts of cadmium, iron, zinc and silver.

3 Environmental concerns

The effects that nanotechnologies have on our plants, animals and ecosystems are not fully understood. The increase in the use of nanomaterials could have implications for the environment.

4 Lack of safety checks

Some applications used in a number of food products and medicines must be independently assessed before they go on the market. For products such as cosmetics, however, it's up to the manufacturer to provide evidence of safety. This means products are often not checked externally by independent experts.

5 Gaps in regulation

It isn't always easy to find where nanotechnologies are being used. Some companies use the term in their marketing, many others do not. The Government does have a voluntary reporting scheme for manufacturers but so far, the response has been very limited.

As existing regulations don't discriminate by size, there's a lack of clarity over how they apply to nanomaterials. Manufacturers don’t have to disclose which manufactured nanomaterials they use, so you can't keep track of your exposure.

The most comprehensive list of the types of developments taking place is compiled by the Woodrow Wilson Centre in the US. This is regularly updated, and you can browse their Nanotechnology Consumer Products Index online.