Australia Publishes Additional Guidance for Assessment Certificate Applicants Introducing Nanoscale Chemicals

The Australian Industrial Chemicals Introduction Scheme (AICIS) posted a news item on December 19, 2022, reminding assessment certificate applicants that extra information is required for chemicals at the nanoscale. AICIS has published extra guidance on the data concerning the nanoscale-specific physicochemical properties that must be provided. AICIS states that nanoscale means a particle size range of one to 100 nanometers (nm). An introduction at the nanoscale is a “specified class of introduction” if the substance:

• Is introduced as a solid or is in a dispersion; and
• Consists of particles in an unbound state or as an aggregate or agglomerate, where at least 50 percent (by number size distribution) of the particles have at least one external dimension in the nanoscale.

If the chemical is at the nanoscale and is categorized as an assessed introduction, information about the chemical’s identity and physicochemical properties must be provided, including:

• Shape of the particle;
• Particle size and particle size distribution (PSD);
• Volume-specific surface area;
• Surface chemistry — the chemical nature of the surface of a particle;
• Surface charge;
• Measured data describing dispersibility (if relevant and information is available);
• Measured data on particle concentration;
• Measured data describing dustiness (only required if inhalation exposure is likely to occur);
• Measured data or suitable alternatives describing the biological (re)activity;
• Data on photoreactivity (if relevant); and
• Human health hazards.

AICIS notes that all Organization for Economic Cooperation and Development (OECD) Test Guidelines available for testing human health toxicity endpoints are considered applicable in the absence of equivalent testing guidelines for nanoscale chemicals.