One of the main concerns in the plastics sector and the food industry in particular is including recycled plastic material in packaging. RECYCLING INVITRO NIAS, a project being carried out at AIMPLAS, the Plastics Technology Centre, has a two-fold mission: to develop an innovative, efficient method for decontamination of polypropylene so that the resulting recycled content can be included in food contact materials, and to optimize NIAS risk assessment methods by means of in vitro bioassays and thus provide a complementary analytical tool to ensure the safety of packaged food in contact with recycled materials.
Packaging made from recycled materials: the current scenario
The first goal is based on EU targets for the inclusion of recycled material in packaging. In fact, the European Food Safety Authority (EFSA) has defined a series of decontamination processes to obtain recycled plastic for food contact materials. This protocol mainly involves submitting a dossier containing all the information on the recycling process used, the challenge test, decontamination efficiency and results of the corresponding migration tests.
Therefore, in the initial part of the RECYCLING INVITRO NIAS project, surrogate contaminants approved by the EFSA are used to spike the material. The spiked material is analysed to determine the surrogate level and then submitted to the decontamination process. The decontaminated material is then analysed again to determine the yield of decontamination, i.e. the reduction of each surrogate level.
Food packaging materials: the problem of unknown substances
Packaging materials and food contact packaging must ensure consumer safety, especially when recycled material is used.
During the production process of plastic packaging, i.e. from making pellets to forming packaging, known substances are used whose migration levels from the material into the food are analysed for regulatory compliance and thus ensure food safety. These substances, known as IAS (intentionally added substances) are easily identified and include monomers, catalysts and solvents, which are intentionally added during the packaging manufacturing process. However, there has been growing concern in recent years about the presence of unknown substances not intentionally added during the packaging manufacturing process. These substances are commonly known as NIAS (non-intentionally added substances).
NIAS were first defined in Article 3 of Regulation (EU) 10/2011. The Preamble of this Regulation states that any potential health risk from these substances should be assessed by the manufacturer in accordance with internationally recognized scientific principles on risk assessment. Despite this legislative framework, there are currently no clear instructions on handling unknown substances or assessing their risk, and there is a significant lack of information on the requirements set out in the legislation.
There are many different types of NIAS depending on their source. Broadly speaking, there are two main sources of NIAS: (i) impurities in the additives and substances used; and (ii) reaction intermediates formed during the production, decomposition or reaction process.
In the context of the project, concern about NIAS increases considerably when recycled materials are involved due to the previous plastic material or the recycling process.
As a result, companies must make a considerable effort to identify and quantify NIAS. However, the analytical techniques available do not ensure 100% food safety.
In vitro bioassays: a tool for risk assessment of recycled materials
Given this scenario, it is essential to standardize a comprehensive process assessment method that can handle all possible NIAS. The use of in vitro bioassays is therefore proposed as a tool for assessing the risk of recycled materials. These in vitro techniques are based on cell cultures and are very useful for risk assessment of unknown substances in complex mixtures because they study overall toxicity. This property makes cell culture techniques an essential part of analysis for food and consumer safety.
RECYCLING INVITRO NIAS: goals
In order to achieve the proposed results, the project will be divided into the following stages: 1) the polymer is contaminated with a surrogate contaminant; 2) the contaminated polymer is submitted to a decontamination process; and 3) the processed polymer is tested to assess the efficiency of the decontamination process.
AIMPLAS and the collaborating companies (PET y CIA, SP BERNER, ITC Packaging and ACTECO), as well as the funding bodies of the Valencian Regional Government through IVACE grants and EU ERDF funds, thus aim to provide solutions based on decontamination, the use of recycled materials for food contact and the development of standardized methods for risk assessment of recycled material using analytical techniques with in vitro bioassays based on cell cultures.
The project is funded by the Valencian Community’s Ministry for Sustainable Economy, Production Sectors, Trade and Employment through IVACE grants. These grants are targeted at technology centres in the Valencian Community to develop non-economic R&D projects in collaboration with companies in 2022.