Since first citations of the term “Nanotechnology”, scientific, industrial, public and political stakeholders have called for a robust regulatory framework to address the potential toxicological concerns surrounding these exciting new materials.
It is the promise of novel and useful properties from nano sizes of familiar materials that prompts a reappraisal of our knowledge of their potential toxicology and environmental impact. These are effectively new materials. The argument goes that, without public and political confidence, this new science risks fear and distrust, rather than being embraced as providing a multitude of solutions to challenges in the fields green energy, world food production or pharmaceutical advancement, to name but a few.
In October 2011 the EU Commission published a recommended definition of Nanomaterials (1). This definition is not the complete framework, but it is a significant step towards it. Observers of embryonic nanotechnology regulation recognised this definition as the missing jigsaw piece in planned legislation; witness the French government largely adopting the definition’s wording and getting draft legislation on compulsory labeling of Nanomaterials out for consultation in under three months. Meanwhile other stakeholders in fields including nanomaterial manufacture and workplace exposure, handling, labeling, transportation and environmental fate now find they have an authoritative definition to slot into nascent regulation.
The key points of the definition are these:
1) It is a Nanomaterial if any of these three criteria are met:
a) At least 50% of the particles by count have one dimension external between 1 and 100nm.
b) The material has a surface area greater than 60m2/cm3.
c) The substance appears on an “include” list that captures materials such as graphene, which would otherwise fall outside the definition.
2) The definition includes naturally-occurring as well as manufactured and incidentally manufactured particles.
3) There are no specific recommendations on characterisation methods to meet these specifications.
4) The definition is a recommendation, not a regulation; however its provenance bestows authority.
Despite protracted and energetic attempts by SCENIHR (the Scientific Committee on Emerging and Newly Identified Health Risks, part of the Directorate General for Health and Consumers) to draw stakeholders into consultation, much of industry and the scientific community appear taken by surprise here. One can sympathise with the compliance officers in, for example, tyre manufacture or cement production, which suddenly find themselves within the nanotechnology industry.
Sympathize one might, but now a period of reflection is required to understand the scientific logic that generated this definition.
Reading back through SCENIHR’s publication, “Scientific Basis for the Definition of the Term “Nanomaterial”, they describe in depth the reasoning behind the definition. SCENIHR exhaustively discuss the possible measures and their benefits, and make clear the large areas of ambiguity and difficulty in these judgments. Then, with some moral courage, they draft this definition, and in so doing take a step forward in supplying the urgent need for regulation.
The 100nm upper limit is essentially historic, coming from original definitions in nanotechnology. It was arbitrary then, and is so now, but it is a start point. Given this definition is specific to regulation, these numbers have to be precise to be enforceable. Specifying count rather than weight per cent recognises that chemical reactivity increases per mass dose for smaller particles. Parameters more closely relating to potential toxicity are missing – these are likely to follow on from this initial size-based definition. Regarding the lack of recommended characterisation methodologies, one need look no further than diesel combustion emissions or the water industry for precedents, where regulatory need sets scientists a measurement challenge – and maybe that is the right way to drive development of practical measurement methodologies?
Let me clearly state my interest here – NanoSight’s NTA (Nanoparticle Tracking Analysis) is at least a partial solution to the nanoparticle counting requirement, and in combination with occasional electron microscopy to inform the bottom end of the 1 – 100nm range, we have a unique and practical, readily-implementable solution.
As the dust settles following the initial publication, reflect on the significant positive drivers from industry in support of legislation; Big business surely seeks to see nanotechnology de-risked? Potential adverse public reaction hangs over nanotechnology, limiting investment and curbing strategic intent. More cynically perhaps, big business deals better with regulation than SMEs; here is a barrier to entry that will ultimately lead to profitability in this sector.
To conclude, we welcome this definition as a starting point to deliver regulation on potential toxicity. There is much research work to be done, and having this definition, this building block in place, will surely enable government investment in research to go the next steps, from simple physical parameters to the far more complex challenges of bioavailability and bio interaction at the heart of toxicology. If industry and regulators can get this right, then far from labeling “contains nanomaterial” being in the smallest permissible font, we might see “Contains Nano” in a bright splash of colour, implying progressiveness, advanced and useful technology, and above all, trustworthiness.