After three years of hard work, International Standards Organization (ISO) Technical Committee TC229—set up in 2005 to develop nanotechnology-related standards—has finally begun delivering the goods.  And the first documents off of the blocks tackle head-on the challenges of working safely with engineered nanomaterials.

September saw the publication of the Technical Specification 27687—“Nanotechnologies—Terminology and definitions for nano-objects—Nanoparticle, nanofibre and nanoplate” (ISO/TS 27687).  True to its title, TS 27687 does exactly what it promises… what you get is beautifully crafted definitions of the terms “nanoparticle” , “nanofibre” and “nanoplate”.  But what is clever about this document is that it develops a systematic hierarchy of terms under the umbrella of “nano-objects”.  Clever, because it neatly resolves the question of “when is a nanoparticle not a nanoparticle” that so often paralyzes discussions on handling nanomaterials safely.

According to TS 27687, a nano-object is a material with either one, two or three dimensions in the nanoscale (roughly, but not exclusively, 1 nm – 100 nm).  Under this overarching term come nanoparticles (having all three external dimensions in the nanoscale), nanoplates (with only one external dimensions in the nanoscale) and nanofibres (nano-objects with two similar dimensions in the nanoscale, and a third dimension that is significantly larger).

Nanofibres are further subdivided into three categories: Nanowires (electrically conductive nanofibres), nanotubes (hollow nanofibres) and nanorods (rigid nanofibres).

The result is a neat and logical way of describing nanoscale materials that differentiates between objects that have previously all been lumped together as nanoparticles.

TS 27687 is not directly focused on health and safety—this is a general Technical Specification designed to aid the development and application of nanotechnologies.  Yet I suspect that the primary utility of this document will be to establish a common language for addressing health and safety concerns when handling nanomaterials that could become airborne when handled.  In recognition of this, the introduction to the Technical Specification states:

“It is … essential that regulators and health and environmental protection agencies have available reliable measurement systems and evaluation protocols supported by well-founded and robust standards”

My guess is that TS 27687 will help a great deal in developing such systems and protocols.

But there is clearly more to working safely with engineered nanomaterials than being able to tell a nano-rod from a nano-plate.  The international nanotechnology standards community obviously though the same, because hot on the heels of TS 27687 comes ISO Technical Report 12885, “Nanotechnologies—Health and safety practices in occupational settings relevant to nanotechnologies” (ISO/TR 12885).  Published in early October, TR 12885 presents an in-depth assessment of the issues surrounding and possible solutions to working safely with engineered nanomaterials.  At 79 pages long, it is perhaps the most weighty document addressing nanotechnology to come out of a standards organization to date!

TR 12885 is heavily based on the NIOSH document “Approaches to Safe Nanotechnology: An Information Exchange with NIOSH” (originally published in 2005, and updated in 2006).  While much of the information presented closely reflects that in the NIOSH document, the ISO Technical Report expands significantly on the original document in a number of areas.  For instance, TR 12885 goes into far greater depth on exposure monitoring and exposure control than the NIOSH document.

This new report isn’t perfect. For instance, I was surprised to see no mention of the DuPont/Environmental Defence Nano Risk Framework in the Product Stewardship section.  And it would have been useful to have a fuller discussion on risk management techniques such as control banding and how they might be applied to working with engineered nanomaterials [see end notes for more information].  But as a comprehensive review of the issues relevant to working safely with engineered nanomaterials, it’s not bad.

However, this new guide on health and safety practices for nanotechnologies is entering an already-crowded marketplace.  ASTM International were the first standards kids on the block with E 2535-07 (Standard Guide for Handling Unbound Engineered Nanoscale Particles in Occupational Settings), published in October 2007.  This was followed a few weeks later by BSI guide PD 6699-02:2007 (Nanotechnologies – Part 2: Guide to safe handling and disposal of manufactured nanomaterials), published in December 2007.  And of course, you have the original NIOSH document, that beat all the others in its first incarnation by two years—having hit the streets in October 2005.

So does this new document from ISO add anything to the mix?

Having looked through the new Technical Report, I have to say yes.  But this is a qualified yes: The ISO document is great for laying out the current state of knowledge and offering options and possibilities for working safely with engineered nanomaterials, but it falls short on clear and concise advice.  In contrast, BSI PD 6699-02 offers what I have previously described as a “shop-floor manual for making decisions where the rubber hits the road.”  ASTM E 2535-07 is similarly more direct in its guidance, although more narrowly focused on what are termed “unbound nanoparticles.”

At the end of the day, these three documents complement each other.  ISO TR 12885 is the reference manual, while BSI PD 6699-02 and ASTM E 2535-07 provide on-the-job advice that is unencumbered with over-much background and analysis.  None of them are perfect—the ISO document is perhaps too reticent in providing guidance, and struggles to keep up with the latest developments (perhaps belying it’s origins in a document published originally three years ago), while the BSI and ASTM International guides could be described as too simplistic in places.  Yet together, they form a firm foundation for ensuring safer workplaces when handling engineered nanomaterials.  And as such they are all highly recommended.

But back to the ISO documents.  These are both strong documents to come out of ISO TC229, and will be extremely useful in helping to develop the knowledge, protocols and methodologies necessary for working safely with engineered nanomaterials.

All we need now is a new guide to make sense of the alphabet soup that these standards organization documents seem to emerge from!

End Notes

The work programme of ISO TC229 can be accessed here.

It should be noted that you have to pay for the privilege of owning ISO TS 27687, ISO TR 12885 and ASTM E 2535-07.  BSI PD 6699-02 on the other hand, is free.

And on this note, I cannot resist but point out that the core of ISO TS 27687 is twelve defined terms.  I make that just over $4 per term if you purchase the document!  But for $4, you couldn’t get a more beautifully crafted term ☺

Control banding remains an interesting option when it comes to making practical judgements on minimizing exposure to engineered nanomaterials in the absence of good information, which is why I was surprised not to see more discussion of it in the ISO document.  A fuller discussion on the utility of the concept for working with nanomaterials can be found here, and a possible implementation, developed by the Nanotechnology Industries Association, can be accessed here.

And finally, for future reference, this blog entry should be referred to as TTS-AM:23A4FD5PO245FF6/TTFN-2008

Andrew Maynard