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Safe Work Australia’s two new reports, Europe’s Nanodevice project, and the UK’s HSE nanomaterials handling

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Over the last few weeks in March (2013), there was a sudden burst of health and safety reports and initiatives released by Safe Work Australia, the European Commission’s Nanodevice project, and the UK’s Health and Safety Executive, respectively.

According to a Mar. 19, 2013 news item on Nanowerk, Safe Work Australia released two reports (Note: Links have been removed),

Safe Work Australia Chair Ann Sherry AO today released two research reports examining nanotechnology work health and safety issues.

The reports: Investigating the emissions of nanomaterials from composites and other solid articles during machining process and Evaluation of potential safety (physicochemical) hazards associated with the use of engineered nanomaterials are part of a comprehensive program of work on nanotechnology safety managed by Safe Work Australia which started in 2007.

The March 18, 2013 Safe Work Australia media release, which originated the news item,  provides some information about the approaches and models being used to analyse and develop policies,

In releasing the reports Ms Sherry noted the perceived safety risks of nanomaterials and that a precautionary approach is being taken by the Commonwealth towards nanomaterials under the National Enabling Technologies Strategy.“

While the risk to human health and safety from a number of these materials and applications is low some nanomaterials are potentially more hazardous, for example carbon nanotubes,” Ms Sherry said.

“The National Industrial Chemicals Notification and Assessment Scheme (NICNAS) has recommended carbon nanotubes be classified as suspected carcinogens unless product-specific evidence suggests otherwise.”

Under the model Work Health and Safety (WHS) laws all duties which apply to the handling of materials and to technologies in general also apply to nanomaterials and nanotechnologies. Minimisation of exposure to nanomaterials at work is essential until there is sufficient data to rule out hazardous properties. Research has shown if conventional engineering controls are designed and maintained effectively, exposure to nanomaterials can be significantly reduced.

As a result of the findings of these reports Safe Work Australia will prepare guidance material on combustible dust hazards including nanomaterials.

Here’s more about the reports (from their respective webpages),

Investigating the emissions of nanomaterials from composites and other solid articles during machining processes

This report by CSIRO considers the potential health risk of emissions from machining processes.

The report finds that significant quantities of material, which can present health risk, are emitted from composites by high energy machining processes like cutting with an electric disc saw or band saw. If the composite contains a hazardous nanomaterial, the health risk from the dust may be higher. Lower energy processes like manual cutting will result in lower exposures and lower potential health risk.

Evaluation of potential safety hazards associated with the use of engineered nanomaterials

This report by Toxikos Pty Ltd examines safety hazards associated with engineered nanomaterials and the implications in regard to workers safety.

The report finds that dust clouds of some engineered nanomaterials could give rise to strong explosions if the dust cloud contains a high enough concentration of nanomaterials and if an ignition source is also present. The report gives examples of these. However in a well-managed workplace, emissions from nanotechnology processes will be very significantly below the minimum dust concentration needed for an explosion.

A Mar. 20, 2013 news item on Nanowerk focused on the European Commission’s Nanodevice project,

European researchers in the Nanodevice project are investigating the safety aspects of nanomaterial production. Their plan laid down in 2009 was to develop new concepts, reliable methods and portable devices for detecting, analysing and monitoring airborne ENMs in the workplace. The latest feedback from the team suggests the project has delivered on its promise.

The project has concluded work on seven new ‘nanodevices’, which have been calibrated and tested for use in work environments exposed to nanoparticles. This work, alongside findings from materials studies and research into the association between ENM properties and their biological impacts, will appear in a new nanosafety handbook, called “Safe handling of manufactured nanomaterials: particle measurement exposure assessment and risk management”.

Complex research like this calls for an integrated, multidisciplinary approach,” confirms Nanodevice’s project leader, Dr Kai Savolainen of the Finnish Institute of Occupational Health.

What makes this particular health and safety project special is the focus on affordable monitoring for small and medium-size companies,

With affordable, portable equipment, even small companies can regularly measure their workers’ exposure to potentially harmful particles. When compared with a growing body of data from other workplaces, a more accurate assessment of risk and occupational health and safety emerges.

Prior to Nanodevice’s portable solutions, regular nanosafety checks could cost up to €200 000. The instrumentation hauled in from outside weighed hundreds of kilos and needed several experts to gather and analyse data from multiple sites. Big companies could afford this, but Europe’s important SME sector struggled with the cost.

“We’ve developed devices like a personal nanoparticle monitor for less than €200 that almost any company can afford and quickly learn to use,” says Dr Savolainen. Worn by a worker, the system collects exposure information, but needs to be plugged into a computer to download the data. This is not ideal, so Nanodevice is keen to develop this into a real-time sensing and monitoring device linked to the internet and databases.

“Today, lack of ‘big’ accurate data makes it hard to know if exposure values are too low,” explains Dr Savolainen, “so our work helps the scientific community build a large database on exposure levels in the working environment.” This means companies, regulators and stakeholders will have access to reliable information from which to base risk-assessment decisions and develop standards for occupational exposure levels for different types of ENMs.

“Thanks to our work, the ‘big picture’ is that people won’t have to be concerned about lack of information on exposure levels. This reduces uncertainty about ENM safety and fosters more innovation in nanosciences in general,” he concludes.

You can find out more about the Nanodevice project here.

Finally, the UK’s Health and Safety Executive released a guidance (I think we’d call them guidelines here in Canada) according to a Mar. 28, 2013 news item on Nanowerk (Note: A link has been removed),

The UK’s Health and Safety Executive (HSE) has released a new guidance (“Using nanomaterials at work”; pdf)that describes how to control occupational exposure to manufactured nanomaterials in the workplace. It will help you understand what you need to do to comply with the Control of Substances Hazardous to Health Regulations 2002 (COSHH) (as amended) when you work with these substances.

There’s more information about the guidance on the Using nanomaterials at work webpage where you can also find the document,

If you work with nanomaterials this guidance will help you protect your employees. If you run a medium-sized or large business, where decisions about controlling hazardous substances are more complex, you may also need professional advice. This guidance will also be useful for trade union and employee health and safety representatives.

This guidance is specifically about the manufacture and manipulation of all manufactured nanomaterials, carbon nanotubes (CNTs) and other bio-persistent high aspect ratio nanomaterials (HARNs). It has been prepared in response to emerging evidence about the toxicity of these materials.

The control principles described can be applied to all nanomaterials used in the workplace. Any differences in the approach between control of CNTs and other bio-persistent HARNs to any other type of nanomaterials are highlighted in the text.

For anyone who wants a direct link to the guidance, go here.

Carbon nanotubes safe handling guide from Australia

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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.