Microplastics and Nanoplastics: What It Means for NZ Plastics

This article was originally published in the Environment Committee’s ‘Sustainability News’ newsletter. For more content like this, Members can email katy@plastics.org.nz to make sure you’re subscribed!

What Are the Reports Telling Us?

Despite currently limited monitoring, MNPs have been detected across air, soils, beach sediments, wastewater, waterways, and flora and fauna in Aotearoa.

Polymer types identified include many of those commonly used in New Zealand, including PP, PMMA, PE, PC, PVC, PET and nylon 66, alongside lower amounts of PS, PU, PLA, PBAT, PCL and PVA/MA.

Research has identified potential ecological and human-health effects associated with MNP exposure, but significant uncertainties remain around the magnitude of these risks, exposure levels, and dose-response relationships.

The Health Risk Assessment also considers the potential role of chemicals associated with MNPs, including additives and non-intentionally added substances (NIAS). The reports note that recycled materials can contain a more complex mixture of NIAS, with uncertainties around their identity and concentration.

In other words, while gaps exist to determining exact risk, the reports highlight some potential risks and advise a precautionary approach.

What Is Relevant to Plastics Manufacturers and Recyclers?

The reports also identify manufacturing and mechanical recycling as potential sources of MNP releases, including through wastewater and atmospheric pathways.

These releases are broader than pellet loss alone and can include dust, fines and other small particles generated through processing, handling, or recycling operations.

This is an area where further research and improved monitoring methods will be important in understanding the scale and significance of industrial releases. However, good housekeeping, stormwater management and spill-response practices can significantly reduce the potential for material loss.

Occupational exposure

The updated Health Risk Assessment identifies some occupational environments, including plastic recycling facilities, as environments where workers may experience elevated airborne MNP exposure compared with the general population.

This does not establish that workers in these environments are experiencing adverse health effects from MNP exposure. However, it reinforces the importance of appropriate existing workplace controls around dust, ventilation, extraction, housekeeping, and worker exposure.

The Regulatory Landscape

Internationally, microplastics and releases of plastic particles are receiving increasing policy attention.

Proposals considered through the ongoing UN Global Plastics Treaty negotiations have included measures addressing plastic pellet loss, intentionally added microplastics and other releases of plastics to the environment. These negotiations remain ongoing and there is not yet an agreed Global Plastics Treaty.

New Zealand already restricts plastic microbeads in certain wash-off products through the Waste Minimisation (Microbeads) Regulations 2017. Other sources of primary and secondary MNPs are not subject to specific MNP regulation.

The newly released reports recommend improved and coordinated monitoring across air, water, soil, and source pathways. However, there are currently no established New Zealand environmental thresholds for MNPs, and methods for sampling, identifying and measuring them are still developing. MNP analysis can also be technically complex and expensive, particularly at smaller particle sizes.

This makes it difficult to establish regulatory limits or consistently compare results between studies and locations.

International developments suggest increasing policy and regulatory attention on MNP releases. In New Zealand, these reports strengthen the evidence base for further monitoring and policy consideration, although significant evidence and methodological gaps remain.

What Could This Mean for Industry?

There are several areas Plastics NZ will continue to watch.

Improved monitoring could provide a much clearer picture of where MNPs are coming from and the relative contribution of different sources. Over time, this may lead to greater expectations around preventing or monitoring releases from identified sources, including industrial operations.

There may also be growing customer, supply-chain and public expectations for businesses to demonstrate how they prevent plastics from entering the environment.

For industry more broadly, there is a reputational risk if plastics manufacturing and recycling are perceived as significant sources of MNP contamination without recognition of the controls already in place or the relative contribution of different sources.

It will therefore be increasingly important that our industry can demonstrate credible practices to prevent avoidable plastics loss.

What Can Industry Do Now?

The good news is that there are practical steps industry can take now, without waiting for the science or regulatory framework to settle.

Regardless of how future regulation develops, preventing avoidable releases of pellets, flakes and powders is sensible environmental and operational practice.

Operation Clean Sweep (OCS) provides a practical framework for plastics-handling sites to identify potential material-loss pathways, improve controls and demonstrate good practice.

Undertaking an OCS advisory audit can help sites identify where pellets, flakes or powders could escape through areas such as material transfer, storage, loading and unloading, stormwater systems and waste handling, and identify practical improvements often missed through internal checks.

Certification can then provide independent evidence that appropriate systems and practices are in place.

For more information about Operation Clean Sweep or to arrange an advisory audit, contact Katy@plastics.org.nz.

Not a plastics-handling site?

Material suppliers, brands and other organisations selling or specifying plastic products and packaging can also help drive responsible handling throughout the supply chain by joining OCS as a supporter.

Find out more through the Operation Clean Sweep NZ website.

Ministry for the Environment – Microplastics and nanoplastics in soil, water, and air and associated Health Risk Assessment.

On 25 August, the Ministry for the Environment released the Microplastics and nanoplastics in soil, water, and air report, alongside an updated Health Risk Assessment. Together, these documents provide a stocktake of the current state of knowledge around the presence, sources and potential impacts of microplastics and nanoplastics (MNPs).

The reports are relevant to our industry because plastics manufacturing and recycling are among the potential pathways identified for MNP release and occupational exposure. They also provide an indication of the issues likely to receive increasing attention from researchers, regulators and the wider community.

An important point of context is that the science is still developing. The report assesses the overall state of knowledge as “medium/unresolved” and the updated Health Risk Assessment identifies MNPs as a credible emerging risk warranting further research and monitoring but does not establish direct evidence of adverse health outcomes in humans.

So, what do we know, what does it mean for our industry, and what can we sensibly do now?