Aimplas study evaluates reusable food packaging safety in high temperatures

Aimplas’ Plastics Technology Centre is leading research into the risks associated with exposing reusable plastic food packaging to high temperatures, such as microwaves and dishwashers.

The Safereuse project began in June 2024 and will conclude this month. Packaging Insights speaks to Mamen Moreno, a researcher at the Food Contact and Packaging laboratory in Aimplas, about the importance of standardized food safety procedures for reusable packaging.

“While the full analysis of results is still underway, preliminary findings indicate that overall migration and specific metal migration tests yield satisfactory results. These values not only comply with regulatory limits but also remain stable after exposure to microwaving and dishwashing,” says Moreno.

No structural compromise

The project, funded by the Valencian Institute of Competitiveness and Innovation and the European Regional Development Fund, aims to establish a methodology for food safety testing and consumer health protection and help companies comply with regulatory requirements.

Domestic dishwashing is more aggressive toward reusables than microwaving, finds the study.Moreno adds: “Currently, there are standardized methodologies to independently evaluate functionality and food safety. However, there is a lack of integrated protocols that simultaneously assess both dimensions, particularly through the combined analysis of NIAS (non-intentionally added substances), microplastics, and bioassays.”

The product evaluated the impact of domestic and industrial dishwashing materials and found that while domestic dishwashing was more aggressive than microwaving reusable plastic food containers, it did not compromise the containers’ structural integrity. 

“Building trust” in plastic 

Critics of plastic point to the damaging effect of single-use plastic pollution on the environment and the irreversible presence of microplastics in the human body as evidence of its danger. 

However, some argue that the “demonization” of plastic is not conducive to tackling the global pollution crisis. Moreno adds that Aimplas’s research could “help shift negative perceptions and promote a more realistic and balanced view of plastics, their health impacts, and their environmental footprint.”

She adds: “High temperatures can potentially increase the release of volatile NIAS. However, our findings suggest that their presence tends to diminish with repeated exposures, likely due to their initial exposure.”

“A similar trend has been observed in the cytotoxicity of the extracts, which also decreases over successive uses, indicating a stabilization of the material’s performance over time.”

Ensuring safe innovation

The Safereuse project represents a “step forward” in understanding the dangers of reusable plastic food packaging, ensuring that future innovation does not compromise consumer health. 

With this project, Aimplas aligns with the UN’s Sustainable Development Goals (SDGs 3, 8, 9, and 12) to promote safety in reusable plastic materials and reduce the risk of exposure to dangerous substances.

“The main objective of the study is to evaluate the safety of reusable plastic containers commonly subjected to microwaving and dishwashing,” says Moreno.

“Specifically, we aim to determine whether these practices contribute to the release of harmful substances or microplastics and to assess the overall suitability of these containers for repeated use in real-life conditions.”

Aimplas indicates that the project can help companies innovate safely and sustainably.