A Fast and Automated Strategy for the Identification and Risk Assessment of Unknown Substances (IAS/NIAS) in Plastic Food Contact Materials by GC-Q-Orbitrap HRMS: Recycled LDPE as a Proof-of-Concept

Role of quality assessment of the recycled packaging material in determining its safety profile as food contact material

Food packaging waste significantly impacts global environmental changes, prompting the adoption of a green circular economy approach. Recycling packaging waste is a critical element of this strategy. However, it faces challenges related to the quality of recycled materials and concerns about their safety. Thus, this review aimed to highlight different analytical methods alone or in combination to evaluate the quality of the recycled material. Furthermore, the safety and health aspects related to the migration of contaminants and their relevant regulations have also been discussed. An important parameter while selecting an appropriate recycling method is the composition and nature of the recyclate, for instance, HDPE (High-Density Polyethylene), PET (Polyethylene Terephthalate), and PP (Polypropylene) materials can be recycled using mechanical and chemical recycling, however, PVC (Polyvinyl Chloride) and PS (Polystyrene) present challenges during mechanical recycling due to lower molecular weight and complex compositions, thus are often downcycled into lower-grade products. Still, recycled papers can be more problematic than recycled plastics due to the nature of the materials and the impact of recycling. The literature review suggested that three quality properties i.e., presence of low molecular weight compounds, degree of degradation, and composition should be analyzed by using different spectroscopic, thermo-mechanical, and chromatographic techniques to obtain a detailed understanding of recycled material quality. Furthermore, recycling should be done in such a way that the migration of contaminants should be lower than the migratory limits set by the relevant authorities to avoid any toxicological effects.

Non-targeted identification and risk assessment of unknown substances in disposable plastic tableware by GC-Orbitrap HRMS

Disposable plastic tableware was widely used and it was particularly important to identify potential hazardous substances in it and evaluate the risk to humans health. In this study, 85 substances were identified in 60 samples (22 bowls, 20 sporks, and 18 straws) by methanol extraction and non-targeted analysis using GC-Orbitrap HRMS. Subsequently, 14 high-risk substances were further screened and their migration in the samples was measured in three food simulants. Finally, based on the proposed safety limit assessment scheme for EU- authorized and unauthorized substances, the risk assessment of exposure to high-risk substances in disposable plastic tableware was performed for three age groups. The results showed that the dibutyl phthalate and bis(2-ethylhexyl) phthalate in some samples exceeded the safety limit value. Overall, the risk of bowls was lower than spock and straws, and the potential exposure risk for young children was higher than that of adults and older children.

Understanding intentionally and non-intentionally added substances and associated threshold of toxicological concern in post-consumer polyolefin for use as food packaging materials

The use of post-consumer recycled (PCR) polymers in food contact materials (FCMs) can facilitate achieving a circular economy by reducing environmental waste and landfill accumulation. This study aimed to identify potentially harmful substances, including non-intentionally added substances (NIAS) and unapproved intentionally added substances (IAS), in polyolefin samples from material recovery facilities using gas-chromatography mass-spectrometry. Selected phthalates and bisphenols were quantified by targeted gas-chromatography tandem mass-spectrometry. The analysis detected 9 compounds in virgin polymers and 52 different compounds including alcohols, hydrocarbons, phenols in virgin and hydrocarbons, aromatic, phthalates, organic acids, per- and polyfluoroalkyl substances (PFAS) in PCR polymers. The Cramer classification system was used to assesses the Threshold of Toxicological Concern associated with the detected compounds. The PCR sample showed a slightly higher proportion of Cramer Class III compounds (48.08 %) than the virgin sample (44.44 %), indicating higher toxicity potential. Quantification detected bisphenols only in PCR material including BPA (2.88 ± 0.53 μg/g), BPS (5.12 ± 0.003 μg/g), BPF (3.42 ± 0.01 μg/g), and BADGE (4.638 μg/g). Phthalate concentrations were higher in PCR than virgin samples, with the highest levels detected as DIDP, at 6.18 ± 0.31 μg/g for PCR and 6.04 ± 0.02 for virgin. This study provides critical understanding of the safety and potential risks associated with using PCR polyolefins from different sources in food contact applications.

Non-target screening and human risk assessment for adult and child populations of semi-volatile organic compounds in residential indoor dust in Spain

In this work, an analytical strategy based on non-target screening of semi-volatile organic compounds and subsequent risk assessment for adult and child populations has been conducted for the first time in household indoor dust samples in Spain. The methodology was based on a microwave-assisted extraction followed by gas chromatography coupled to high resolution mass spectrometry determination, using a hybrid quadrupole-orbitrap analyzer. The procedure was applied to 19 residential indoor dust samples, collected in different Spanish regions (namely Galicia, La Rioja, Catalunya, the Balearic Islands, and the Valencian Region). From the generated data, 4067 features were obtained, of which 474 compounds were tentatively identified with a high level of identification confidence (probable structure by library spectrum match or confirmed by reference standard), using a restrictive set of identification criteria. Most of the identified chemicals were natural products, metabolites, additives, and substances with industrial applications in the field of foods, cosmetics, pharmaceuticals, pesticides, and plastics. Finally, risk assessment was carried out by applying the threshold of toxicological concern approach, showing that risk to adult and child populations associated with the presence of the identified substances in the indoor dust was not expected, although the existence of indoor environments with conditions of potential risk cannot be discarded under a worst-case scenario approach.

Mass Spectrometry-Based Techniques for the Detection of Non-Intentionally Added Substances in Bioplastics

The safety of food contact materials is a hot topic since chemicals can migrate from packaging into food, thus raising health concerns about and/or producing changes in the organoleptic properties of foodstuffs. Migration tests are required to demonstrate the compliance with current regulations and to investigate the transferred compounds. In this context, mass spectrometry is the analytical technique of choice for the detection and quantitation of both intentionally added substances, such as antioxidants, stabilizers, processing aids, and non-intentionally added substances (NIAS). Untargeted strategies represent a major analytical challenge, providing a comprehensive fingerprinting of the packaging material and migrating components, allowing for NIAS identification. Hyphenated mass spectrometry-based techniques have been devised for screening the presence of migrating contaminants and for quantitation purposes. Both low-resolution (LRMS) and high-resolution (HRMS) methods were screened, with a special emphasis on the latter because of its capability to directly characterize food contact materials with minimal/no sample preparation, avoiding chromatographic separation, and reducing sample handling, analysis costs, and time. Examples related to the migration of contaminants from existing or newly developed bioplastic materials will be discussed, providing an overview of the most used MS-based methods, covering the state-of-the-art approaches from 2012 up to 2022.

Editorial for the Special Issue "Risk Assessment of Food Contact Materials/Articles"

Food packaging is made of four main materials, namely plastic, cardboard, glass and metals (aluminium and steel), as well as many other materials (wood, waxes, corks, etc [...].

Determination of 60 Migrant Substances in Plastic Food Contact Materials by Vortex-Assisted Liquid-Liquid Extraction and GC-Q-Orbitrap HRMS

A GC-HRMS analytical method for the determination of 60 migrant substances, including aldehydes, ketones, phthalates and other plasticizers, phenol derivatives, acrylates, and methacrylates, in plastic food contact materials (FCM) has been developed and validated. The proposed method includes migration tests, according to Commission Regulation (EU) 10/2011, using four food simulants (A, B, C, and D1), followed by vortex-assisted liquid–liquid extraction (VA-LLE) and GC-Q-Orbitrap HRMS analysis in selected ion monitoring (SIM) mode, with a resolving power of 30,000 FWHM and a mass accuracy ≤5 ppm. The method was validated, showing satisfactory linearity (R² ≥ 0.98 from 40 to 400 µg L⁻¹), limits of quantification (40 µg L⁻¹), precision (RSD, 0.6–12.6%), and relative recovery (81–120%). The proposed method was applied to the analysis of field samples, including an epoxy-coated tin food can, a drinking bottle made of Tritan copolyester, a disposable glass made of polycarbonate, and a baby feeding bottle made of polypropylene, showing that they were in compliance with the current European regulation regarding the studied substances.