The production of food contact materials (FCMs) from plant biomass is popular because renewable feedstocks can help to reduce harmful CO2 emissions to the atmosphere. Other environmental impacts, such as land use, can partially be reduced using waste biomass (FPF reported and here). FCMs made from renewable feedstocks include bio-based plastics, paper & cardboard, or composite materials with plant fibers. Because some of these materials are relatively new and undergoing constant innovation, the chemical composition and health concerns are not well known. Three recent studies investigated sustainability claims and safety aspects of plant-based or plant-containing FCMs.
In June 2024, Minmin Tang and co-authors from Nanjing University, China reviewed hazardous substances in FCMs containing plant fibers in the journal Food Packaging and Shelf Life. The chemical composition of the final FCM can vary widely depending on the region the feedstock came from, season, supplier, and other factors. They found that hazardous chemicals could originate from raw materials, production processes, or during use. Polluted soils, the use of pesticides, and the incorporation of polymers and additives can increase the number and diversity of substances in the final plant-based article.
For some of the well-known problematic substances, such as pesticides, polychlorinated biphenyls (PCBs), melamine (CAS 108-78-1), and plasticizers, targeted analytical methods or even rapid detection methods have been established. For hazardous substances that do not have standardized, targeted testing regimes, the authors recommend multi-dimensional separation techniques and high-resolution mass spectrometry (HRMS) to get a broad picture of all chemical components in an FCM. However, the authors note that analytical bottlenecks remain.
Non-intentionally added substances (NIAS) are particularly problematic since they are rarely found in current chemical libraries (making it difficult to positively identify when detected with HRMS, FPF reported), and often lack analytical standards or toxicity data. These bottlenecks hinder a comprehensive understanding of an FCM’s chemical composition and its subsequent risk assessment. The authors also note that “researchers have defined the concept of risk assessment too simplistically, including identifying substances and conducting risk assessment through methods such as TTC [Threshold of Toxicological Concern].” (FPF reported) They recommend using complementary methods such as in vitro bioassays (FPF reported).
Krista Bouma from The Netherlands Food and Consumer Product Safety Authority (VWA) and co-authors recently published an analytical study of 28 bio-based food contact articles (FCAs) from the Dutch market in the journal Food Additives & Contaminants: Part A. They found that many articles labeled “eco-friendly” or “natural” had plastic coatings that rendered the product non-biodegradable (FPF reported), and often contained pesticide residues, PFAS, phthalates, and antioxidants. Many samples contained the fungicide carbendazim (CAS 10605-21-7), a reproductive toxicant, with detected levels up to 5.7 mg/kg. The PFAS 6:2 FTOH (CAS 647-42-7), and the potentially endocrine-disrupting antioxidant 2,4-di-tert-butylphenol (CAS 96-76-4), were also detected at concerning levels. The authors question the “eco-friendliness” and safety of these bio-based FCMs, suggesting that the “labeling is misleading and may be considered ‘greenwashing’”.
Such labels will need to be substantiated in Europe under the forthcoming Green Claims Directive (FPF reported) and Peru is implementing a similar program (FPF reported).
In addition to man-made hazardous chemicals, plants and other biomass can naturally contain harmful substances, including allergens. Gluten, found in wheat and other grains, can cause severe immune reactions and damage to the small intestine in people with celiac disease. Wheat can be a feedstock for bio-based FCMs. A study by Johanna Mossburger and Katharina Anne Scherf from the Karlsruhe Institute of Technology (KIT), Germany focused on whether gluten can migrate from wheat-based FCMs. This study confirmed that gluten can migrate from wheat-based FCMs, especially after prolonged contact with foodstuffs. After 15 minutes, four of the six tested materials had transferred gluten to liquid food simulants; longer contact time increased the migrated concentrations. Gluten from one wheat-based plate even migrated to solid foods within 20 minutes. Thus, people with celiac disease may be affected by wheat-based FCMs. To ensure safety, the authors call for extending allergen labeling to FCMs, especially “because the raw material used to produce such FCM is often unknown”.
References
Tang, M., et al. (2024). ‘Safety of plant fiber-based food contact materials: Overview of the discovery, identification, detection and risk assessment of unknown risk substances’. Food Packaging and Shelf Life. DOI: 10.1016/J.FPSL.2024.101281
Bouma, K., et al. (2024). ‘Plant-based food contact materials: presence of hazardous substances’. Food Additives & Contaminants: Part A. DOI: 10.1080/19440049.2024.2357350
Mossburger, J., & Scherf, K. A. (2024). ‘Gluten migration from biodegradable food contact materials poses a risk to celiac disease patients’. European Food Research and Technology. DOI: 10.1007/s00217-024-04570-4
Other recent research
Simonetti, G., et al. (2024). ‘Studies of potential migration of hazardous chemicals from sustainable Food Contact Materials’. Foods. DOI: 10.3390/foods13050645
Li, H., et al. (2024). ‘Potential safety concerns of volatile constituents released from coffee-ground-blended single-use biodegradable drinking straws: A chemical space perspective’. Journal of Hazardous Materials. DOI: 10.1016/J.JHAZMAT.2024.133663
Thakur, V., & Satapathy, B. K. (2024). ‘Migration Concerns of Biopolymer‐Based Food Packaging’. Agro‐Waste Derived Biopolymers and Biocomposites. DOI: 10.1002/9781394175161.ch15
