Development of Health and Safety Standards to Support Nanotechnology Work Health and Safety Management

Nanotechnologies bring the potential for enormous benefit, but there are also some risks associated with its use, given the limited knowledge about the health effects of new nanomaterials. Workers may have the greatest exposure to these nanomaterials and therefore may bear the greatest risks for adverse human health and safety effects. The development and application of effective health and safety standards will help protect the health and safety of people working with nanomaterials.

There are many different types of safety and health standards including those developed by:

• International organisations, such as the Organisation for Economic Cooperation and Development (OECD) and the International Organization for Standardization (ISO).
• Regulatory agencies - examples are standards and specifications such as national workplace exposure standards¹ (Safe Work Australia 2010), and Codes of Practice, including those for safety data sheets and labels, which become mandatory when adopted in regulations.
• National standard-setting bodies such as Standards Australia and the British Standards Institution (BSI) - e.g. the BSI's A guide to safe handling and disposal of manufactured nanomaterials (BSI 2007).
• Industry associations.

This article examines how standards² and related documents can support effective health and safety management by nanotechnology organisations, considers issues associated with the development and use of standards and identifies the potential focus of future work. Australia-specific information is used to illustrate these issues.

Effective Health and Safety Management

Nanotechnology organisations can protect the health and safety of workers by implementation and maintenance of effective standard practices for working with nanotechnologies. However, these practices need to be scientifically sound and effective in practice.

What needs to be in place to achieve effective health and safety management?

Key areas for consideration, shown schematically in Figure 1, are:

• appropriate regulation, i.e. defining what needs to be done
• having useful and reliable information to explain how to manage health and safety effectively
• external support for organisations
• internal resources to manage work health and safety effectively, and
• verifying the effectiveness of standard practices.

Figure 1: Effective health and safety management

International Standards Development for Nanotechnologies

For nanotechnologies, international health and safety standards and related documents including technical specifications, technical reports and guidance materials are being developed through the ISO Nanotechnology Technical Committee (TC 229) Working Group 3 and through the OECD Working Party for Manufactured Nanomaterials (WPMN).

The focus areas for ISO TC 229 Working Group 3 are shown in Figure 2 and these form the basis of the roadmap for the working group. Specific Working Group 3 projects are shown in Table 1, and ISO published a Technical Report on Health and Safety Practices in Occupational Settings Relevant to Nanotechnologies in 2008 (ISO 2008).

Figure 2: ISO TC229 Working Group 3 Focus Areas

Table 1: ISO TC229 Working Group 3 Projects

Details of the OECD Working Party for Manufactured Nanomaterials (WPMN) Program are in Table 2 and a number of reports on work under this program have been published (OECD 2010). A formal liaison has been established between ISO TC229 and OECD WPMN to ensure coherency between the work programs.

These standards support work health and safety management through:

• supporting the regulation of nanotechnologies, and
• providing information, e.g. through guidance documents, to directly support nanotechnology organisations.

Table 2: OECD WPMN Program

Regulation of Nanotechnologies

The regulation of nanotechnologies needs to clearly define for duty holders what needs to be done. This section covers:

• The current approach to regulation in Australia.
• Issues impacting on the regulation of nanomaterials.
• Actions being taken in Australia to progress these issues.
• Key documents that are adopted into regulation, or referenced by regulation - thus becoming regulatory or mandatory standards.

Issues relating to the regulation of nanotechnologies are summarised in Figure 3 below.

Figure 3: Regulation of nanotechnologies

Approach to Regulation of Nanotechnologies in Australia

Australia's work health and safety legal duties require that (DIISR 2009):

• manufacturers ensure that, so far as reasonably practicable, substances are manufactured to be safe if they are used as intended
• suppliers ensure that, so far as reasonably practicable, substances supplied to research laboratories and workplaces are safe if they are used as intended
• employers provide and maintain a working environment that is safe, and
• workers follow work health and safety requirements to protect their own health and safety, and that of others who may be affected by the work they are doing.

General obligations under work health and safety legislation, including chemical regulations for hazardous substances and dangerous goods, need to be met for nanomaterials and nanotechnologies³. Engineered nanomaterials may continue to be regulated under the current work health and safety regulatory framework. However, a number of issues need to be addressed to ensure the effective regulation of engineered nanomaterials, for example to support effective compliance activity by regulators.

The Australian National Industrial Chemicals Notification and Assessment Scheme (NICNAS) has recently developed a proposal for regulatory reform of industrial nanomaterials in Australia (NICNAS 2009), which will contribute to work health and safety regulation.

Currently there is only limited hazard and risk information for most nanomaterials. Where there is a lack of information, the use of a precautionary approach when handling engineered nanomaterials is warranted, until evidence of their hazardous properties is generated. This may be interpreted as, where there is the potential for worker exposure, organisations working with nanomaterials should use the highest levels of controls that are practicable and reduce exposures as low as practicable. This differs from the current requirements of legislation which are limited to providing what is reasonably practicable, and are based on a sound understanding of hazards and risks.

Issues Impacting on the Regulation of Nanotechnologies

Definition of Nanomaterials

ISO has developed a working definition of nanotechnology as: The application of scientific knowledge to control and utilize matter at the nanoscale, where size-related properties or phenomena can emerge. Nanoscale has been defined as the size range from approximately 1nm to 100nm⁴ (ISO 2008a), with a note which states that Properties that are not extrapolations from a larger size will typically, but not exclusively, be exhibited in this size range. For such properties the size limits are considered approximate. This added note is critically important from a work health and safety management viewpoint.

The basis of work health and safety management is managing the hazard associated with the material and thus whether a particle is 80 nm or 120 nm (i.e. inside and outside the nanoscale range) is somewhat irrelevant from a work health and safety viewpoint if the hazard associated with the material is unchanged. Poland et al (2008) showed that exposing the mesothelial lining of the body cavity of mice to; (a) dispersed bundles and singlets of long and intermediate length multi-walled carbon nanotubes with mean diameter of 85 nm, and (b) long bundles and ropes of multi-walled carbon nanotubes with mean diameter of 165 nm, resulted in asbestos-like, pathogenic behaviour in both cases.

General Issues

General issues that impact on the regulation of nanotechnologies include:

• adding detail within the frameworks to cover nanotechnologies appropriately
• improving understanding of the hazardous properties of engineered nanomaterials
• developing nanotechnology work health and safety measurement capability
• improving understanding of the effectiveness of workplace controls, and
• ensuring consistency internationally.

Australian Program to Progress These Issues

In order to progress these issues, Safe Work Australia is implementing the Nanotechnology OHS Program (Safe Work Australia 2010a) and a significant number of nanotechnology work health and safety research projects have been commissioned to support the program (Table 3).

Table 3: Projects commissioned under Safe Work Australia's Nanotechnology OHS Program

Key Documents that are Adopted into Regulation, or Referenced by Regulation - thus becoming Regulatory or Mandatory Standards

Regarding national standards and Codes of Practice with legal standing, the detail within these is being examined to check that it covers nanomaterials appropriately. A specific issue under consideration is how these instruments can appropriately cover the current situation, with the levels of uncertainty about hazards and risks associated with new engineered nanomaterials.

Safe Work Australia is drafting information to cover nanomaterials for a number of regulatory policy documents (Safe Work Australia 2009), supporting work on the development of model work health and safety laws for Australia (Safe Work Australia 2009a). These include:

• Draft National Code of Practice for the Preparation of Safety Data Sheets (SDS). Section 5.9 contains new extra physicochemical parameters to cover nanomaterials.
• Draft Australian Criteria for the Classification of Hazardous Chemicals. Section 1.5 specifically covers the classification of engineered nanomaterials.

These draft documents have been through a public comment process and are currently being reviewed and revised based on comments received.

Safety Data Sheets and Labels

The ISO TC229 Working Group 3 project on Preparing Safety Data Sheets (SDS) for Manufactured Nanomaterials is a good example of how regulatory standards can be supported by the development of non-regulatory international standards and related documents. This project directly supports regulation. The project acknowledges the existence of current documents (e.g. the Australian National Code of Practice for MSDS) and is developing advice on what to put in each of the 16 sections of a Safety Data Sheet, i.e. in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) format, for nanomaterials specifically.

Labelling is an issue which is the source of concern globally. There have been a number of calls for mandatory labelling of nanomaterials for workplace use, e.g. by the Australian Council of Trade Unions (ACTU 2009). Current work health and safety legislative requirements for labelling of workplace chemicals require that the specific hazardous properties of the material be identified on the label, irrespective of the form of the material. Therefore this information must be provided for any nanomaterials or products containing nanomaterials which have hazardous properties. However, this system relies on hazard information being available. The issue of what precautionary information should be provided for nanomaterials of uncertain hazards remains. A further important issue is maintaining consistency with the GHS.

Exposure Standards

Exposure standards are important occupational hygiene standards that support regulation. There are a small number of exposure standards for nanomaterials which are not new, e.g. a number of forms of carbon black and fumed silica nanoscale, and these substances have Australian National Exposure Standards of 3mg/m³ and 2mg/m³ respectively (Safe Work Australia 2010). The US NIOSH has proposed exposure limits for fine and ultrafine TiO₂ of 1.5mg/m³ and 0.1 mg/m³ respectively⁵ (NIOSH 2005), and for comparison, the Australian National Exposure Standard for TiO₂ is 10mg/m³ (Safe Work Australia 2010).

The British Standards Institution (BSI) in the guide to safe handling and disposal of manufactured nanomaterials (BSI 2007) proposed Benchmark Exposure Levels (BELs) for groups of manufactured nanomaterials, with the note that:

"These are intended to provide reasonably cautious levels and are based in each case on the assumption that the hazard potential of the nanoparticle form is greater than the large particle form. This assumption will not be valid in all cases. Although these benchmark levels relate to current exposure limits, they have not been rigorously developed. Rather, they are intended as pragmatic guidance levels only and should not be assumed to be safe workplace exposure limits."

The proposed BELs are:

• Fibrous nanomaterials - 0.01 fibres/ml.
• Nanomaterials classified as carcinogenic, mutagenic, asthmagenic or reproductive toxins (CMAR) - 0.1x Workplace Exposure Limit (WEL) bulk material.
• Insoluble nanomaterials - 0.066 x WEL bulk material.
• Soluble nanomaterials - 0.5 x WEL bulk material.

While there has been debate about the BELs quantification, the grouping of materials and the potential application of the BELs (e.g. on how to measure fibrous nanomaterials), they give a starting point for consideration of exposure standards. Grouping nanomaterials may be the most practical approach for defining standards rather than on a nanomaterial-by-nanomaterial basis, given the ever expanding number of engineered nanomaterials being used. Grouping is also effective in facilitating the use of control banding approaches. These BELs are currently being examined in a Safe Work Australia commissioned project.

In a recent review of the toxicology and health hazards of engineered nanomaterials (Drew et al 2009), noted that:

"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"

Given there may potentially be serious adverse health effects from inhalation exposure to carbon nanotubes, to clarify requlatory requirements and thus to inform mandatory standards, Safe Work Australia has commissioned NICNAS to undertake a health hazard assessment of carbon nanotubes for classification. In addition, to support regulation and organisations handling carbon nanotubes, the Australian Commonwealth Scientific Industrial Research Organisation (CSIRO) has been commissioned to develop guidance for the safe handling and disposal of carbon nanotubes.

Nanotechnology Health and Safety Information

In this section, information on how to protect the health and safety of workers is examined, including the notable contribution of non-regulatory (non-mandatory) standards.

Organisations' Needs

Nanotechnology organisations are of various forms and include research laboratories within universities, small commercial concerns and units within large companies. The information needs of these organisations are different, for example due to varying internal resources to support work health and safety and therefore standards development should reflect the range of needs.

Sources of Health and Safety Information

There are many different sources of non-regulatory nanotechnology health and safety information, including national and international standards, as shown on Figure 4. A recent Australian nanotechnology community attitude and awareness survey (DIISR 2010) noted the importance of the internet in providing information to people on new developments in science and technology and most people advised they would do a Google search.

A growing amount of information is available on:

• Nanomaterial hazards, in particular health hazards. There is a lesser amount of information relating to safety hazards, but a report by the British Health and Safety Laboratories (HSL) on the Fire and explosion properties of nanopowders was recently published (HSE 2010).
• Practices to prevent and control workplace emissions and exposures
• Measurement of nanomaterials emissions and exposures in workplaces
• Risk management approaches.

Figure 4: Nanotechnology Health & Safety Information

Verifying the Effectiveness of Standard Practices

Verifying the effectiveness of standard practices will require measurement of exposures and emissions, during development of the practices e.g. for inclusion in standards, and when implemented in workplaces. The development of measurement standards will be described below. Where there is potential exposure, the use of health surveillance may be appropriate.

However for nanotechnologies, health surveillance practices are not yet available, except where defined for substances without nano-size specificity, e.g. for cadmium and lead (NOHSC 1995). Health surveillance for workers potentially exposed to engineered nanoparticles has been considered by Schulte et al (2008) and the US National Institute for Occupational Safety and Health (NIOSH 2009). This topic will be examined further in a forthcoming conference in July 2010 on Nanomaterials and Worker Health: Medical Surveillance, Exposure Registries, and Epidemiologic Research, arranged by the US NIOSH.

Development of Nanotechnology OHS Measurement Standards

A number of studies have now demonstrated through measurement that conventional occupational hygiene controls (e.g. process enclosure and local exhaust ventilation) can help prevent inhalation exposure to manufactured nanomaterials (Jackson et al 2009).

However, measurement of nanomaterial emissions and exposures is critical in supporting work health and safety management. In relation to development of a standard, a basis may be provided by the Nanoparticle Emission Assessment Technique (NEAT) (Methner et al 2010), developed by the US NIOSH. This is based on:

• the simultaneous use of a Condensation Particle Counter (CPC) and Optical Particle Counter (OPC) to measure the number concentration of airborne particles, and to indicate whether these particles are nanoscale particles, or larger particles, e.g. aggregates and agglomerates of nanoparticles, and
• filter-based air sampling for mass concentration measurement and particle characterisation (composition, shape).

This procedure is the basis of the guidance on initial assessment of nanomaterial emissions published by the OECD WPMN in 2009 (OECD 2009). Safe Work Australia has commissioned two projects to validate the use of the OECD WPMN procedure for a range of engineered nanomaterials.

Use of Control Banding for Nanotechnologies

While information on hazards, measurement and controls is being generated, organisations have to control exposures effectively. With limited hazard and risk information available, the control banding approach is a risk management approach to consider. There are a number of ways control banding can be used, for example:

• organisations can undertake a control banding evaluation, e.g. by use of the Control Banding Nanotool (Paik et al 2008, Zalk et al 2009), or
• experts can develop guidance based on control banding, e.g. Figure 3 in the BSI guide to safe handling and disposal of manufactured nanomaterials (BSI 2007). Organisations can then use this guidance as part of a conventional risk assessment process, choosing the right control guidance sheets, developed by experts, for their materials/processes/tasks.

The most suitable approach will depend on the nature of the nanotechnology organisation (as discussed above). ISO TC 229 Working Group 3 Project 8 (Table 1) is examining occupational risk management based on the control banding approach and is considering different approaches to control banding.

External Support for Nanotechnology Organisations

External support may be provided by a number of organisations, such as regulators, policy agencies, industry associations, occupational hygienists or unions (Figure 5). But in order to be able to provide this support, developments are needed to provide:

• standards for measurement of nanomaterials emissions and exposures, and
• specific validated guidance for control of processes.

Figure 5: External Support

Summary

This article has examined how health and safety standards development for nanotechnologies is critical in helping to protect the health and safety of workers. A range of international, national and other standards and related documents are now being developed using information gained by targeted research to support work health and safety management for nanotechnologies. This work includes:

• adding detail to the work health and safety regulatory framework to cover nanotechnologies appropriately
• supporting toxicology research into the hazardous properties of new engineered nanomaterials
• developing standards for nanotechnology work health and safety measurement, and
• providing guidance on effective workplace controls to support organisations.

Acknowledgements

The author acknowledges the contributions of Dr John Miles and Dr Vladimir Murashov for their review and comments on this article.

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