But it has not come up with a legal definition of nanomaterials (yet), says the FDA.
“The draft guidance does not establish a regulatory definition of the term ‘nanotechnology’ or any related vocabulary. Over time, we plan to issue more specific guidances tailored to particular products or classes of products.”
When considering whether an FDA-regulated product contains nanomaterials or involves the application of nanotechnology, FDA will in future ask:
- Whether an engineered material or end product has at least one dimension in the nanoscale range (1 - 100 nanometers).
- Whether an engineered material or end product exhibits properties or phenomena, including physical or chemical properties or biological effects attributable to its dimensions, even if these fall outside the nanoscale range, up to one micrometer.
These considerations will apply not only to new products, but also where manufacturing changes alter the dimensions, properties or effects of a material or its components, says the FDA.
Legal minefield
Agreeing on a legal definition of nanomaterials that satisfies food manufacturers, regulators, enforcement bodies and consumers has proved challenging on both sides of the Atlantic, however.
If a definition concentrates on size alone, it will encompass a vast swathe of perfectly innocuous and naturally-occurring nanomaterials in products from milk to chocolate, confusing shoppers without serving any useful purpose, point out food manufacturers.
But building a definition around ‘insoluble’, ‘manufactured’, or ‘engineered’ nanoparticles is also problematic because of the difficulty of pinning down the precise meaning of these terms, argue lawyers.
Even definitions based on whether nanomaterials behave 'significantly' differently to their normal-sized counterparts raise similar issues (what’s the definition of 'significantly'?)
Even agreeing on how to measure such tiny materials is a thorny issue owing to the unusual shape and structure of many nanoparticles. And as particle sizes in many materials are rarely consistent, many substances contain some particles on the nanoscale, and some that are not.
Meanwhile, the cost and complexity of the equipment needed to examine materials at this scale – atomic force or scanning electron microscopes, for example – makes enforcement expensive and challenging.
Unilever: Nano labels must be meaningful and specific
In a round table debate on nanotechnology facilitated by the UK’s Food Standards Agency last year, 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.”
Nanotechnology in food
Nanotechnology promises an exciting range of benefits to consumers from the targeted release of nutrients to antimicrobial biofilms and lighter-weight packaging able to block out oxygen, carbon dioxide and moisture.
Other interesting applications include nano-sensors that could detect pathogens, nano-encapsulation of natural food colours and other bioactives, and nanocellulose for moister bread, crispier crackers and juicier meat products.
Click here for a round-up of nanotechnology applications in food from our sister title FoodManufacture.co.uk.