Nanomaterial control banding risk assessment

To help with risk management, Workplace Health and Safety Queensland has developed a Nanomaterial control banding tool worksheet.

The worksheet is based upon a nanomaterial control banding approach.

There is a general consensus that the hazards associated with nanomaterials will vary depending on the type of material. For example, nanomaterials that are fibrous, insoluble and bio-persistent may potentially pose more health risks than other engineered nanomaterials.

To assist with risk management, a Nanomaterial control banding tool worksheet (PDF, 0.71 MB) document has been developed by Workplace Health and Safety Queensland (WHSQ) based upon a nanomaterial control banding approach described by Paik et al 2008[¹] and incorporates changes suggested by Zalk et al 2009 [²]. In addition, the worksheet contains content on identifying flammability of nanomaterials.

This nanotool is particularly relevant to research facilities where small quantities of nanomaterials are likely to be used but has general application at all nantechnology workplaces. Changes to the nanomaterial control banding worksheet are likely as more information becomes available regarding the hazards and risks associated with nanotechnology.

The tool can be used to assess the following:

• nanomaterial
  • surface reactivity
  • particle shape
  • particle diameter
  • solubility
  • carcinogenicity
  • reproductive toxicity
  • mutagenicity
  • dermal toxicity
  • asthmagen
• parent material
  • toxicity
  • carcinogenicity
  • reproductive toxicity
  • mutagenicity
  • dermal toxicity
  • asthmagen
• dustiness/mistiness/propensity to become airborne
• amount of chemical used during the task
• number of workers with similar exposure
• frequency and duration of operation.

The nanotool allows the determination of severity and probability scores based upon the above as follows:

Severity Score: Sum of all severity factors. Maximum score is 100. Out of the 100 points, 70 points are based on characteristics of the nanomaterial and 30 points are based on characteristics of the parent material. Thus, more weight is given to nanoscale characteristics as follows:

• 0-25: Low severity
• 26-50: Medium severity
• 51-75: High severity
• 76-100: Very high severity.

Probability Score: Sum of all exposure factors. Maximum score is 100. These factors determine the extent to which employees may be potentially exposed to nanoscale materials, primarily through inhalation, but also through dermal contact.

• 0-25: Extremely unlikely
• 26-50: Less likely
• 51-75: Likely
• 76-100: Probable.

Nanomaterial control banding is particularly useful for nanotechnology processes because of the:

• uncertainties regarding the toxicology of engineered nanoparticles
• difficulty in characterising and measuring engineered nanoparticles
• uncertainty as to which nanoparticle metrics should be characterised, and
• absence of exposure standards.

Nanomaterial control banding can be used to:

• complement traditional industrial hygiene methods of air sampling and analysis
• provide a formal process for incorporating professional judgement about risk and control, and
• should be facilitated by a person with sufficient occupational hygiene experience and knowledge.

Further instruction on using the nanotool can be obtained from WHSQ staff and/or reference to the articles published by Paik et al 2008, and Zalk et al 2009.