Tag Archives: CSIRO

Carbon nanotubes safe handling guide from Australia

For anyone who’s been looking for a guide on handling carbon nanotubes, it seems the Australians released a relevant publication back in March 2012. There’s some really good information in it (happily, they covered a few items I have long been curious about). The Aug. 1, 2012 news item on Nanowerk provides more details about the document,

The potential risks from exposure to carbon nanotubes have been identified and examined in research studies. To help people work safely with carbon nanotubes, Safe Work Australia commissioned the Commonwealth Scientific and Industrial Research Organisation (CSIRO) to develop the guidance document Safe Handling and Use of Carbon Nanotubes (pdf).

I went to look at the 42-page PDF document and found this description of single-walled and multi-walled carbon nanotubes (CNT)  along with a description of the health concerns as outlined in a US NIOSH (National Institute of Occupational Safety and Health) document on p. 4 print version, p. 6 PDF,

SINGLE-WALLED AND MULTI-WALLED CARBON NANOTUBES

In general, there are two groups of CNTs:

  • Single walled carbon nanotubes (SWCNTs) are a single cylinder of carbon atoms forming a tube. They are normally around 1nm in diameter, but may be up to 5nm.
  • Multi walled carbon nanotubes (MWCNTs) consist of two or more concentric layers of carbon nanotubes with a hollow core typically 2-30nm in diameter. For example, double-walled carbon nanotubes have two concentric layers. MWCNTs may be stiffer than SWCNTs and may potentially be of greater health and safety risk due to the possibility of piercing the body’s pleural tissue.

Potential health concerns

The toxicity of CNTs is the subject of much discussion and experimentation. This document does not aim to consider or analyse this literature in detail. However, CNTs can be bio-persistent and have the potential to exist as fibre-like structures.

NIOSH (2010) reports that currently there are no studies reported in the literature of adverse health effects in workers producing or using CNTs. However use is not yet widespread, and there can be a long latency before the development of disease. The concern about worker exposure to CNTs arises from results of animal studies, showing adverse lung effects including pulmonary inflammation and fibrosis.

NIOSH (2010) also reports that animal studies have also shown asbestos-type pathology associated with exposure to longer, straighter CNT structures. Mesothelial tumors have been reported in a susceptible strain of mice after intraperitoneal injection of longer MWCNTs (10-20 μm in length) but not by short MWCNTs (<1 μm in length).

In a recent review, Toxikos (2009) reports: “Evidence leads to a conclusion that as a precautionary default: all biopersistent CNTs, or aggregates of CNTs, of pathogenic fibre dimensions could be considered as presenting a potential fibrogenic and mesothelioma hazard unless demonstrated otherwise by appropriate tests…” (Toxikos 2009).

There is also evidence that CNTs and structures of CNTs that are not of fibre-like shape may also be hazardous.

They give guidance on on two methods for risk management (pp. 5 – 7 print version, pp. 7-9 PDF),

Risk management methods — Overview

Risk management, including work with CNTs, is focused on preventing incidents, injury, illness, property damage, and environmental harm.

The general risk management process, which is applicable to working safely with CNTs, is illustrated in Figure 1. It shows that risks may be controlled with or without conducting a detailed risk assessment. If, after identifying a hazard, you already know the risk and how to control it effectively, you may implement the controls without further assessment.

Guidance on the general risk management process is available in the Code of Practice: How to Manage Work Health and Safety Risks.

This document provides guidance on two options to manage the risks.

Method 1 — Carbon nanotubes risk management with detailed hazard analysis and exposure assessment 1

This approach should be used when it is necessary to gather and evaluate information on characteristics of the carbon nanotubes or structures of carbon nanotubes and/or on potential levels of exposure throughout the process and associated work, to assess risk. The approach involves:

collecting relevant information to identify the hazards

assessing the risks

implementing appropriate control measures, and

monitoring and reviewing the effectiveness of control measures.

Information can be collected from external sources, including the manufacturer and supplier. This will include information on:

physical and chemical characteristics of carbon nanotubes

potential health effects

control options.

Specialised knowledge of the production processes, analysis methods and controls will be required to undertake a full risk management process.

Method 2 — Carbon nanotubes risk management by Control Banding

Control banding for CNTs involves a simplified form of the risk management approach, where specific controls are recommended based on process risk. The CNTs are considered to be hazardous, therefore the controls are based on the potential level of exposure. Control banding can be used when production and manufacturing processes are well understood, potential exposure routes are known and safe work procedures are developed.

As with Method 1 above, this approach involves implementing appropriate controls for specific processes and monitoring and reviewing control effectiveness.

After my encounter with Canadian firefight Peter McBride (he disagreed vociferously with some of my comments in an April 25, 2012 posting), I’ve been interested in any fire safety issues posed by nanomaterials. There’s not much in this report but here it is (p. 10 of the print version, p. 12 PDF),

Safety hazards are considered in the CSIRO’s safety data sheet for MWCNTs (CSIRO 2009). CNTs are not considered to be dangerous goods. In relation to fire and explosion hazards the following points are noted:

  • CNTs are difficult to combust and ignite.
  • However in general, accumulations of fine dust (420 microns or less) may burn rapidly and fiercely if ignited; once initiated larger particles up to 1400 microns diameter will contribute to the propagation of an explosion.

This is the last bit I’m excerpting from the report and it’s an example of how ventilation practices were changed to bring exposure rates to airborne CNTs below recommended levels,

REDUCING EXPOSURE TO AIRBORNE CNTS — EXAMPLE

An assessment of airborne exposure to MWCNTs in a research laboratory manufacturing and handling MWCNTs found a total particulate concentration of 430 μg/m3 for a blending process in the absence of exposure controls (Han 2008). The implementation of ventilated enclosure of the blending process reduced airborne concentrations of MWCNTs from 172.9-193.6 tubes/cm3 to 0.018-0.05 tubes/cm3. At airborne levels of 0.018-0.05 tubes/cm3, the airborne MWCNTs concentration is significantly below the NIOSH REL of 7 μg/m3.

I included that last bit as it demonstrates the possibilities for minimizing risk. Unfortunately, there’s no way yet of ascertaining whether the minimum levels for exposure have been set correctly.

So, here’s my final word on this guide, it provides some good introductory material, guidelines for analyzing  the best safety practices, a helpful bibliography, and a reminder that we still don’t know much about the risks of handling CNTs. For those who won’t make their way through a 40-page document, there’s an information sheet.

Australians weigh in on Open Access publication proposal in UK

Misguided is the word used in the June 20, 2012 editorial for The Conversation by Jason Norrie to describe the UK proposal to adopt ‘open access’ publishing, from physorg.com,

The British government has enlisted the services of Wikipedia founder Jimmy Wales in a bid to support open access publishing for all scholarly work by UK researchers, regardless of whether it is also published in a subscription-only journal.

The cost of doing so would range from £50 to £60 million a year, according to an independent study commissioned by the government. Professor Dame Janet Finch, who led the study, said that “in the longer term, the future lies with open access publishing.” Her report says that “the principle that the results of research that has been publicly funded should be freely accessible in the public domain is a compelling one, and fundamentally unanswerable.”

Norrie’s June 20,2012  editorial can also be found on The Conversation website where he includes responses from academics to the proposal,

Emeritus Professor Colin Steele, former librarian of the Australian National University, said that although report was supportive of the principles of open access, it proposed a strategy that was unnecessarily costly and could not be duplicated in Australia.

“The way they’ve gone about it almost totally focuses, presumably due to publisher pressure, on the gold model of open access,” he said. “As a result of that, the amount of money needed to carry out the transition – the money needed for article processing charges – is very large. It’s not surprising that the publishers have come out in favour of the report, because it will guarantee they retain their profits.

“It certainly wouldn’t work in Australia because there simply isn’t that amount of research council funding available.

Stevan Harnad, a Professor in the Department of Psychology at Université du Québec à Montréal, said the report had scrubbed the green model from the UK policy agenda and replaced it with a “vague, slow evolution toward gold open access publishing, at the publishers’ pace and price. The result would be very little open access, very slowly, and at a high price … taken out of already scarce UK research funds, instead of the rapid and cost-free open access growth vouchsafed by green open access mandates from funders and universities.”

For anyone not familiar with the differences between the ‘green’ and ‘gold models, the Wikipedia essay on Open Access offers a definition (Note: I have removed links and footnotes),

OA can be provided in two ways

  • Green OA Self Archiving – authors publish in any journal and then self-archive a version of the article for free public use in their institutional repository, in a central repository (such as PubMed Central), or on some other OA website What is deposited is the peer-reviewed postprint – either the author’s refereed, revised final draft or the publisher’s version of record. Green OA journal publishers endorse immediate OA self-archiving by their authors. OA self-archiving was first formally proposed in 1994 by Stevan Harnad [emphasis mine]. However, self-archiving was already being done by computer scientists in their local FTP archives in the ’80s, later harvested into Citeseer. High-energy physicists have been self-archiving centrally in arXiv since 1991.
  • Gold OA Publishing – authors publish in an open access journal that provides immediate OA to all of its articles on the publisher’s website. (Hybrid open access journals provide Gold OA only for those individual articles for which their authors (or their author’s institution or funder) pay an OA publishing fee.) Examples of OA publishers are BioMed Central and the Public Library of Science.

I guess that Wikipedia entry explains why Hamad is quoted in Norrie’s editorial.

While money is one of the most discussed issues surrounding the ‘open access publication’ discussion, I am beginning to wonder why there isn’t more mention of the individual career-building, institution science reputation-building and national science reputation-building that the current publication model helps make possible.

I have posted on this topic previously, the May 28, 2012 posting is my most comprehensive (huge) take on the subject.

As for The Conversation, it’s my first encounter with this very interesting Australian experiment in communicating research to the public, from the Who We Are page,

The Conversation is an independent source of analysis, commentary and news from the university and research sector — written by acknowledged experts and delivered directly to the public. Our team of professional editors work with more than 3,100 registered academics and researchers to make this wealth of knowledge and expertise accessible to all.

We aim to be a site you can trust. All published work will carry attribution of the authors’ expertise and, where appropriate, will disclose any potential conflicts of interest, and sources of funding. Where errors or misrepresentations occur, we will correct these promptly.

Sincere thanks go to our Founding Partners who gave initial funding support: CSIRO, Monash University, University of Melbourne, University of Technology Sydney and University of Western Australia.

Our initial content partners include those institutions, Strategic Partner RMIT University and a growing list of member institutions. More than 180 institutions contribute content, including Australia’s research-intensive, Group of Eight universities.

We are based in Melbourne, Australia, and wholly owned by The Conversation Media Trust, a not-for-profit company.

The copyright notice at the bottom of The Conversation’s web pages suggest it was founded in 2010. It certainly seems to have been embraced by Australian academics and other interested parties as per the Home page,

The Conversation is an independent source of analysis, commentary and news from the university and research sector viewed by 350,000 readers each month. Our team of professional editors work with more than 2,900 registered academics and researchers from 200 institutions.

I wonder if there’s any chance we’ll see something like this here in Canada?

Nature’s nanostructures: a new book

Australia’s national science agency, CSIRO (Commonwealth Scientific and Industrial Research Organization), issued a March 21, 2012 news release announcing a new book on biomimcry (or biomimetics), Nature’s Nanostructures edited by CSIRO scientists. From the news release,

A new book, which explores how nature’s own laboratory has been producing some of the world’s most advanced nanomaterials for millions of years, has been released.

Nature’s Nanostructures, edited by CSIRO scientists Dr Amanda Barnard and Dr Haibo Guo, focuses on the animals, minerals and extra-terrestrial bodies that have been producing nanomaterials for millennia.

In the first collection of its kind, each chapter charts the complex characteristics of different nanomaterials, including the iridescent scales on the exoskeletons of beetles, magnetic particles in the beaks of pigeons and gold particles found in ores.

The book brings together studies of entomology, geology, astronomy, physics, chemistry, molecular biology and health to build a complete picture of naturally occurring nanomaterials.

“I think is it generally assumed that nanomaterials are a relatively new phenomenon but some nanoparticles have been present in animals and minerals for millions of years and are a natural occurrence,” says Dr Barnard, leader of the Virtual Nanoscience Laboratory at CSIRO.

“This book uniquely charts the diversity of these naturally occurring materials. It is both humbling and comforting to realise that nature did it first and that nanomaterials are not as new as we think,” she adds.

Cameron Chai’s March 21, 2012 news item about the book on Azonano notes,

New CSIRO research on beetles and the reflective qualities of their shells is included in the book. The chapter titled ‘Photonic Crystals in Beetles’ explores 3D crystals produced by opal weevils and how these nanostructures not only create vivid structural colours, but also reflect light at virtually any angle.

The book also contains research, produced by scientists in the US and Germany, into the different levels of magneto-reception found in the beaks of homing pigeons and how the nanostructures in their beaks work as an efficient magnetic field amplifier.

The book is available for purchase through Amazon. I’ve linked to the Canadian Amazon site so the price is listed in Canadian dollars.

Amanda Barnard has been mentioned here previously in my March 10, 2010 posting and my June 16, 2010 posting.

Bee silk; minnows and silver nanoparticles; David Cramb at U of Calgary finds way to measure nanoparticles in bloodstream; Rock Against Prisons

I had not realized that there’s an international drive to produce artificial insect silk until this morning. According to a news item on Nanowerk,

CSIRO [Australia's Commonwealth Scientific and Industrial Research Organisation] scientist Dr Tara Sutherland and her team have achieved another important milestone in the international quest to artificially produce insect silk. They have hand-drawn fine threads of honeybee silk from a ‘soup’ of silk proteins that they had produced transgenically.

These threads were as strong as threads drawn from the honeybee silk gland, a significant step towards development of coiled coil silk biomaterials.

“It means that we can now seriously consider the uses to which these biomimetic materials can be put,” Dr Sutherland said.

“We used recombinant cells of bacterium E. coli to produce the silk proteins which, under the right conditions, self-assembled into similar structures to those in honeybee silk.

If I understand this rightly,  ‘tinkering’ with bacterium E. coli makes this a transgenic system and I believe it’s a GEO (genetically engineered organism) and not a GMO (genetically modified organism). In any event, it’s also biomimetic because this process mimics a biological system.

On the practical side of things, insect silk could potentially be used for tough, lightweight textiles and medical applications such as sutures. You can read more about this in the Nanowerk news item.

A Purdue University study has added more evidence that silver nanoparticles are toxic to fish. According to the news item on physorg.com,

Tested on fathead minnows ╨ an organism often used to test the effects of toxicity on aquatic life — nanosilver suspended in solution proved toxic and even lethal to the minnows. When the nanosilver was allowed to settle, the solution became several times less toxic but still caused malformations in the minnows.

“Silver nitrate is a lot more toxic than nanosilver, but when nanosilver was sonicated, or suspended, its toxicity increased tenfold,” said Maria Sepulveda, an assistant professor of forestry and natural resources whose findings were published in the journal Ecotoxicology. “There is reason to be concerned.”

Coincidentally, Dr. David Cramb, director of the Nanoscience Program and professor in the department of Chemistry at the University of Calgary, and his colleagues have published a paper about a new methodology they are developing to measure the impact of nanoparticles (no specifics about which ones) on human health and the environment. From the news release on Eureka Alert, [Mar.4.10 ETA since I think the Eureka doesn't last long, here's a link to the same news on Azonano]

Cramb, director of the Faculty of Science’s nanoscience program, and his researchers have developed a methodology to measure various aspects of nanoparticles in the blood stream of chicken embryos. Their discovery is published in the March online edition of Chemical Physics Letters.

“With the boom in nanomaterials production there is an increasing possibility of environmental and/or human exposure. Thus there is a need to investigate their potential detrimental effects,” says Cramb. “We have developed very specialized tools to begin measuring such impacts.”

To close today off, I got a news release from poet Heather Haley (Vancouver, Canada based) about her latest local appearance,

Heather Haley was a member of Vancouver punk bands, the all-girl Zellots and the .45s with Randy Rampage and Brad Kent. Long-lost video of the Zellots will be screened and Heather will interviewed for a live webcast. She will perform poetry from her new collection, “Three Blocks West of Wonderland.” Hope to *see* you there.

ROCK AGAINST PRISONS Live Video Retrospective         Tuesday, March 9, 2010         7:00pm – 11:55pm
Little Mountain Gallery         195 east 26th Ave         Vancouver, BC
On March 9th, the social forces will be mounting an assault on the staid and the bland. From a Punk Rock Swap Meet to a Celebrity Auction, from an ‘umplugged’ stage to a Grand Slam Poetry Karaoke by some of the big stars of 1979, we are getting the Old Gang Together. We review the fabulous footage by doreen grey from the seminal 1979 gig and plan out the 2010 resurgence of the Vancouver Explosion.
Come on out and celebrate Vancouver’s living heritage with those who made it happen: Rabid, Female Hands, Devices, Zellots, Tunnel Canary, AKA, Subhumans. Special appearances. Door Prizes. Live Webcast and Kissing Booth. Fishnet stockings. Oodles of prime swag and fixins. Your every 1979 Punk nightmare come beautifully true.

You can also check out Heather’s latest work on her website.