Currently, the only legal definition for nanomaterials in the EU is enshrined in the Cosmetics Regulation (EC 1223/2009), which defines nanomaterials (for labelling purposes) as “insoluble or biopersistent and intentionally manufactured… with one or more external dimensions or an internal structure on the scale of 1-100-nanometres”.
A second definition – which focuses on “intentionally-produced materials in the order of 100-nanometres or less” - is included in the latest draft of the revised Novel Food Regulation, which also calls for nanomaterials to be labelled on food packaging, something many manufacturers oppose.
A third definition that appears to focus more on size than functionality is being developed by the European Commission's independent Scientific Committee for Emerging and Newly Identified Health Risks.
However, all of the above definitions are problematic, according to scientists and legal experts at last week's workshop, which was organised by Leatherhead Food Research, NanoCentral and the Nanotechnology Knowledge Transfer Network.
Should nano definition be based on size?
If the definition concentrated on size alone, it would encompass a vast swathe of perfectly innocuous and naturally-occurring nanomaterials in products from milk to chocolate, confusing shoppers without serving any useful purpose, said LFR consultant microscopist Kathy Groves.
Precisely how to measure such tiny materials was also a thorny issue owing to the unusual shape and structure of many nanoparticles, and there were not yet standardised, validated means of determining the size and distribution of such tiny components in foods.
Meanwhile, the cost and complexity of the equipment typically used to examine materials at this scale – atomic force or scanning electron microscopes, for example – made enforcement expensive and challenging.
Moreover, given that particle sizes in many materials were rarely consistent, many substances would contain some particles on the nanoscale, and some that were not, she added. “What percentage of nanomaterials make something nano? Are we going to have a ‘may contain nanoparticles’ label?”
How to define engineered nanoparticles
Meanwhile, trying to build a definition around ‘insoluble’, ‘manufactured’, or ‘engineered’ nanoparticles was also problematic because pinning down the precise meaning of these terms was a legal and scientific nightmare, she said.
Even definitions that focused on the issue of whether nanomaterials behaved 'significantly' differently to their normal-sized counterparts weren’t necessarily helpful, she suggested. "What is the definition of 'significantly'?"
Unilever: definition must take several factors into account
In a recent round table debate on nanotechnology facilitated by the Food Standards Agency, Unilever R&D director, regulatory affairs, consumer confidence and sustainability, Charles-Francois Gaudefroy, said several factors needed to be taken into account when coming up with a worakable definition of a nanomaterial.
"[It must take into account] particle size; deliberate engineering; digestibility for nanomaterials used in foods and solubility in conditions of use for materials used in home/personal care products; the characteristic properties of the nanomaterial compared to its non-nano forms.”
As for nano labels, it was important to establish their purpose before ploughing ahead, he stressed: “We support labelling provisions where they provide meaningful specific information to consumers.”
Lord Krebs: no advantage to nano labels
Speaking in a recent debate in the House of Lords, former Food Standards Agency chairman Lord Krebs also expressed concerns about the prospect of nano labels.
“We did not see an advantage in labelling foods that contain nanomaterials, as we could not see what consumers would do with such information when shopping.”
As for a legal definition of nanomaterials, this "should focus not on size alone… but also on functionality; that is, how the nanoscaled material interacts with the human body", he added.