I have often referred to and linked to Andrew Maynard’s writing on nanotechnology issues and am pleased to note he has kindly answered some questions about the Health Canada Working Definition of Nanomaterial. Before launching into his responses, here’s a little more about him.

Dr. Andrew Maynard was originally trained as a physicist and graduated with a PhD from Cambridge, UK  in 1993. He worked for a number of years for the UK Health and Safety Executive moving to the US to work with the National Institute of Occupational Health and Safety where he helped set up a nanotechnology safety programme post 2000 when the NNI was established. By 2005, he was employed at the Project on Emerging Nanotechnologies as their Chief Science Advisor. As of April 2010, he assumed responsibility as director of the Risk Science Center at the University of Michigan School of Public Health. He consults internationally on nanotechnology safety issues. He was a member of the expert panel consulted for the nanotechnology report, Small is Different; A Science Perspective on the Regulatory Challenges of Nanotechnology, published by the Council of Canadian Academies in 2008.

Since the 2008 report for the Council of Canadian Academies, Andrew has adopted a different approach to regulating nanotechnology, a change I first noted in an April 15, 2011 posting on the University of Michigan Risk Science Center blog. Excerpted from that posting,

Engineered nanomaterials present regulators with a conundrum – there is a gut feeling that these materials present a new regulatory challenge, yet the nature and resolution of this challenge remains elusive.  But as the debate over the regulation of nanomaterials continues, there are worrying signs that discussions are being driven less by the science of how these materials might cause harm, and more by the politics of confusion and uncertainty.

The genesis of the current dilemma is entirely understandable. Engineered nanomaterials are typically the product of nanotechnology – a technology that has been lauded as leading to designed materials with unique physical and chemical properties.   Intuitively it makes sense that these unique properties could lead to unique risks.  And indeed a rapidly growing body of research is indicating that many nanoscale materials behave differently to their non-nanoscale counterparts in biological environments. Logically, it seems to follow that engineered nanomaterials potentially present risks that depend on their scale, and should be regulated appropriately.

Yet the more we learn about how materials interact with biology, the less clear it becomes where the boundaries of this class of materials called “nanomaterials” lie, or even whether this is a legitimate class of material at all from a regulatory perspective.

I waffle somewhat largely due to my respect for Andrew and his work and due to my belief that one needs to entertain new approaches for the emerging technologies, even when they make your brain hurt. (Before proceeding with Andrew’s comments and for anyone who’s interested in my take here is, My thoughts on the Health Canada nanomaterial definition.)

In any event, here are Andrew’s responses to my questions,

• I have warm feelings towards this definition, especially the elaboration where I think they avoided the problem of including naturally occuring nanoparticles (as per your comment about micelles in milk); and they specify a size range without being doctrinaire about it. How do you feel about it, given that you’re not in favour of definitions?

The problem is that, while the Health Canada is a valiant attempt to craft a definition based on the current state of science, it is still based on a premise – that size within a well defined range is a robust indicator of novel risk – that is questionable.  Granted, they try to compensate for the limitations of this premise, but the result still smacks of trying to shoehorn the science into an assumption of what is important.

• Do you see any pitfalls?

A large part of the problem here is an attempt to oversimplify a complex problem, without having a clear understanding of what the problem is in the first place.  Much of my current thinking – including questioning current approaches to developing definitions – revolves round trying to work out what the problem is before developing the solution.  But this makes commenting on the adequacy or inadequacy of definitions tricky, to say the least.

• Is there anything you’d like to add?

My sincere apologies, I’ve just got to 5:00 PM on Sunday [Oct. 23, 2011] after working flat out all weekend, and am not sure I have the wherewithal to tackle this before collapsing in a heap.

I am hugely thankful that Dr. Maynard extended himself to answer my questions about the Health Canada definition of nanomaterial. To Andrew: a virtual bouquet of thanks made up of the most stunning flowers and scents you can imagine.