Additives in polypropylene and polylactic acid food packaging: Chemical analysis and bioassays provide complementary tools for risk assessment

Plastic food packaging represents 40 % of the plastic production worldwide and belongs to the 10 most commonly found items in aquatic environments. They are characterized by high additives contents with >4000 formulations available on the market. Thus they can release their constitutive chemicals (i.e. additives) into the surrounding environment, contributing to chemical pollution in aquatic systems and to contamination of marine organism up to the point of questioning the health of the consumer. In this context, the chemical and toxicological profiles of two types of polypropylene (PP) and polylactic acid (PLA) food packaging were investigated, using in vitro bioassays and target gas chromatography mass spectrometry analyses. Plastic additives quantification was performed both on the raw materials, and on the material leachates after 5 days of lixiviation in filtered natural seawater. The results showed that all samples (raw materials and leachates) contained additive compounds (e.g. phthalates plasticizers, phosphorous flame retardants, antioxidants and UV-stabilizers). Differences in the number and concentration of additives between polymers and suppliers were also pointed out, indicating that the chemical signature cannot be generalized to a polymer and is rather product dependent. Nevertheless, no significant toxic effects was observed upon exposure to the leachates in two short-term bioassays targeting baseline toxicity (Microtox® test) and Pacific oyster Crassostrea gigas fertilization success and embryo-larval development. Overall, this study demonstrates that both petrochemical and bio-based food containers contain harmful additives and that it is not possible to predict material toxicity solely based on chemical analysis. Additionally, it highlights the complexity to assess and comprehend the additive content of plastic packaging due to the variability of their composition, suggesting that more transparency in polymer formulations is required to properly address the risk associated with such materials during their use and end of life.

Improving the environmental sustainability of reusable food containers in Europe

Modern lifestyles have popularised the use of food containers, also known as food savers or Tupperware. However, their environmental impacts are currently unknown. To fill this knowledge gap, this paper presents the first comprehensive assessment of the life cycle environmental sustainability of reusable plastic and glass food savers and evaluates different options for improvements, focusing on European conditions. Taking a cradle-to-grave approach, the paper considers twelve environmental impacts, including global warming potential (GWP), acidification, eutrophication, human and ecotoxicities. The results suggest that, for example, the total GWP of using both types of food saver in the European Union (EU) amounts to 653ktCO₂eq./year, equivalent to the annual greenhouse gas emissions of Bermuda. The use stage is the main contributor to the impacts (>40%), related to the washing of containers. Glass food savers have 12%-64% higher impacts than the plastic and should have up to 3.5 times greater lifespan to match the environmental footprint of plastic containers. Three improvement scenarios have been considered at the EU level for the year 2020: low-carbon electricity mix; implementation of the EU eco-design regulation for dishwashers; and adoption of more resource-efficient hand dishwashing techniques. The results suggest that the implementation of all three improvement options would reduce the impacts by 12%-47%. The option with the greatest potential for reducing the impacts (12%-27%) is improved hand dishwashing to reduce the amount of water, energy and detergents used. Thus, policy makers and manufacturers should devise strategies to raise awareness and guide consumers in adopting these techniques with the aim of reducing the environmental impacts associated with reusable food savers used by millions of people worldwide.