The challenge of identifying non-intentionally added substances from food packaging materials: A review

Targeted screening of 11 bisphenols and 7 plasticizers in food composites from Canada and South Africa

A sensitive method based on ultrasound-assisted liquid extraction coupled with liquid chromatography was applied to screen 18 plastic-related contaminants in 168 food composites (namely fish fillets, chicken breast, canned tuna, leafy vegetables, bread and butter) collected in Montreal (Canada), Pretoria and Vhembe (South Africa). Bisphenol A (BPA), bisphenol S (BPS) and seven plasticizers (di-n-butyl phthalate (DBP), diethyl phthalate (DEP), (2-ethylhexyl) phthalate (DEHP), di-(2-ethylhexyl) adipate (DEHA), di-isononyl phthalate (DINP), di-(isononyl)-cyclohexane-1,2-dicarboxylate (DINCH)) were detected in different foods from both countries. DBP and DEP were the most frequently detected contaminants in food collected in Montreal (75% for both) and DINP was the most frequently detected contaminant in food from South Africa (67%). DEHA concentration in packaged fish were significantly higher than the values for non-packaged fish (p < 0.01) suggesting that the packaging film can be one source of DEHA in fish.

Non-targeted screening of extracts from polyester-phenolic can coatings: Identification of new aldehyde molecules from resole-based resins

Phenolic and substituted phenol based resoles are commonly used in the formulation of can coatings. However, migration analyses of these coatings are very little described compared to other coating technologies. While epoxy and polyester have well known migrants with defined formation mechanisms, Non-Intentionally Added Substances (NIAS) specifically related to the phenolic resin are hardly studied in the literature. The goal of the publication is to further explore the influence of the phenolic resole, used in the formulation of can coatings, on extracted NIAS's nature. Six different model polyester-phenolic can coatings were formulated each with a specific phenol, cresol or tertbutylphenol-based resole. Can coating films were extracted for 24 h at 40 °C in acetonitrile before analysis. NIAS identification was done using gas chromatography separation coupled to high resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR) spectroscopy analyses. Cyclic polyester oligomers were found in all extracts, with oligomers found in a range of 10 μg/dm² to 226 μg/dm², without specific influence of the resole used in formulation. While very few or no peaks were detected from cresol- and phenol-based resoles, 48 peaks were specifically observed in coating extracts of formulas with tertbutylphenol-based resoles as well as in their respective resoles. The most intense peaks were identified as aldehyde compounds by HRMS and NMR analysis. These aldehydes were semi-quantified in similar proportions as polyester oligomers. The presence of such aldehydes has never been reported in the literature regarding NIAS in can coatings. Further study will then be needed to better understand the aldehyde formation mechanism and assess the toxicological profile of such chemicals.

Guidance in selecting analytical techniques for identification and quantification of non-intentionally added substances (NIAS) in food contact materials (FCMS)

There are numerous approaches and methodologies for assessing the identity and quantities of non-intentionally added substances (NIAS) in food contact materials (FCMs). They can give different results and it can be difficult to make meaningful comparisons. The initial approach was to attempt to prepare a prescriptive methodology but as this proved impossible; this paper develops guidelines that need to be taken into consideration when assessing NIAS. Different approaches to analysing NIAS in FCMs are reviewed and compared. The approaches for preparing the sample for analysis, recommended procedures for screening, identification, and quantification of NIAS as well as the reporting requirements are outlined. Different analytical equipment and procedures are compared. Limitations of today's capabilities are raised along with some research needs.

Prediction of Collision Cross Section Values: Application to Non-Intentionally Added Substance Identification in Food Contact Materials

The synthetic chemicals in food contact materials can migrate into food and endanger human health. In this study, the traveling wave collision cross section in nitrogen values of more than 400 chemicals in food contact materials were experimentally derived by traveling wave ion mobility spectrometry. A support vector machine-based collision cross section (CCS) prediction model was developed based on CCS values of food contact chemicals and a series of molecular descriptors. More than 92% of protonated and 81% of sodiated adducts showed a relative deviation below 5%. Median relative errors for protonated and sodiated molecules were 1.50 and 1.82%, respectively. The model was then applied to the structural annotation of oligomers migrating from polyamide adhesives. The identification confidence of 11 oligomers was improved by the direct comparison of the experimental data with the predicted CCS values. Finally, the challenges and opportunities of current machine-learning models on CCS prediction were also discussed.

Characterization of Polyester Coatings Intended for Food Contact by Different Analytical Techniques and Migration Testing by LC-MSn

Polymeric coating formulations may contain different components such as cross-linking agents, resins, lubricants, and solvents, among others. If the reaction process or curing conditions are not applied in a proper way, these components may remain unreacted in the polymeric network and could be released and migrate into foods. In this study, several polyester coatings intended for food contact were investigated. Firstly, Fourier-transform infrared spectroscopy with an attenuated total reflectance (ATR-FTIR) spectrometer and confocal Raman microscopy were used to identify the type of coating. Then, different techniques, including gas chromatography coupled to mass spectrometry (GC-MS) and analysis by matrix-assisted laser desorption coupled to time-of-flight mass spectrometry (MALDI-TOF-MS), among others, were used to investigate the potential volatile and non-volatile migrants. Moreover, migration assays were carried out to evaluate the presence of monomers and to tentatively identify possible oligomers below 1000 Da. The analyses were performed by liquid chromatography coupled to ion trap mass spectrometry (LC-MSⁿ). Using the information collected from each analytical technique, it was possible to elucidate some of the starting substances used in the formulation of the polyester coatings analyzed in this study. In migration tests, several polyester oligomers were tentatively identified for which there is not toxicological data available and, therefore, no migration limits established to date.

Occurrence, toxicity and remediation of polyethylene terephthalate plastics. A review

Polyethylene terephthalate is a common plastic in many products such as viscose rayon for clothing, and packaging material in the food and beverage industries. Polyethylene terephthalate has beneficial properties such as light weight, high tensile strength, transparency and gas barrier. Nonetheless, there is actually increasing concern about plastic pollution and toxicity. Here we review the properties, occurrence, toxicity, remediation and analysis of polyethylene terephthalate as macroplastic, mesoplastic, microplastic and nanoplastic. Polyethylene terephthalate occurs in groundwater, drinking water, soils and sediments. Plastic uptake by humans induces diseases such as reducing migration and proliferation of human mesenchymal stem cells of bone marrow and endothelial progenitor cells. Polyethylene terephthalate can be degraded by physical, chemical and biological methods.

The detection and elucidation of oligomers migrating from biodegradable multilayer teacups using liquid chromatography coupled to ion mobility time-of-flight mass spectrometry and gas chromatography-mass spectrometry

Biodegradable materials are increasingly being used in manufacturing processes due to their environmental benefits. In this work, a study has been performed to assess the migration of compounds from biodegradable multilayer teacups to a tea solution. Liquid chromatography in conjunction with ion-mobility quadrupole time-of-flight mass spectrometry has been used for the elucidation of non-volatile compounds. An orthogonal projection to latent structures-discriminant analysis has been carried out to compare the tea after migration against untreated tea used as blank. Headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry has been optimised to analyse the migration of volatile compounds. Eight migrants were identified in the tea, six of which were non-intentionally added oligomers. The degree of migration for hot tea ranged from 0.05 and 4.68 mg/kg, exceeding the specific migration limit. Nevertheless, the migration to cold tea was an order of magnitude lower (between 0.003 and 0.56 mg/kg).

Identification of Potential Migrants in Polyethylene Terephthalate Samples of Ecuadorian Market

Polyethylene terephthalate (PET) is the plastic packaging material most widely used to produce bottles intended for contact with food and beverages. However, PET is not inert, and therefore, some chemical compounds present in PET could migrate to food or beverages in contact, leading to safety issues. To evaluate the safety of PET samples, the identification of potential migrants is required. In this work, eight PET samples obtained from the Ecuadorian market at different phases of processing were studied using a well-known methodology based on a solvent extraction followed by gas chromatography–mass spectrometry analysis and overall migration test. Several chemical compounds were identified and categorized as lubricants (carboxylic acids with chain length of C12 to C18), plasticizers (triethyl phosphate, diethyl phthalate), thermal degradation products (p-xylene, benzaldehyde, benzoic acid), antioxidant degradation products (from Irgafos 168 and Irganox), and recycling indicator compounds (limonene, benzophenone, alkanes, and aldehydes). Additionally, overall migration experiments were performed in PET bottles, resulting in values lower than the overall migration limit (10 mg/dm²); however, the presence of some compounds identified in the samples could be related to contamination during manufacturing or to the use of recycled PET-contaminated flakes. In this context, the results obtained in this study could be of great significance to the safety evaluation of PET samples in Ecuador and would allow analyzing the PET recycling processes and avoiding contamination by PET flakes from nonfood containers.

A risk classification strategy for migrants of food contact material combined with three (Q)SAR tools in silico

The chemical constituents in food contact materials (FCMs) may transfer into food during the contact, which may pose potential risk to humans. So, it is important to evaluate the safety of FCMs. Due to the advantages of cost-effectiveness and high throughput, (Q)SAR tools have been gradually used for risk assessment. In this work, a risk classification strategy for migrants of food contact materials combined with three (Q)SAR tools was developed based on a single endpoint (Mutagenicity) assessment and risk matrix approach, respectively. 419 migrants existing in a self-built toxicology database beneficial from Python crawler technology were evaluated. 5 toxic hazard ranks and 4 risk ranks were obtained for single endpoint assessment and risk matrix respectively, with 21 substances assigned as Toxic hazard Class I and 43 substances assigned as RISK Ⅰ which need the highest safety concern. Besides, for the Toxic hazard Class I substances assessed by the single endpoint, 19 of them were confirmed experimentally, and all of them were overlapped in the RISK Ⅰ substances, which suggests the effectiveness and reliability of this strategy.

Fabric phase sorptive extraction for specific migration analysis of oligomers from biopolymers

Oligomers are potential migrants from polymers or biopolymers intended to food packaging and they have to be under control. In order to comply with European regulation 10/2011, their concentration in migration must be below 0.01 μg g^-1. In this work, fabric phase sorptive extraction (FPSE) was explored as an effective method for extraction and pre-concentration of oligomers migrated from a blend PLA-polyester material. Both food simulant B (3% acetic acid) and juice, as real food, were used for migration experiments. The parameters of FPSE were optimized and the analysis was done by UHPLC-QTOF and UHPLC-QqQ. A total of 21 oligomers were identified, 9 of them coming from PLA and 12 oligomers from the polyester part. These oligomers were formed by adipic acid (AA), phthalic acid (PA) and/or butanediol (BD), ten were cyclic and 11 were linear molecules. Using the optimized FPSE procedure in 3% acetic acid as food simulant, it was possible to identify 3 new compounds that were not detected by direct injection of the simulant into UHPLC-QTOF. In addition, 2 extra compounds, cyclic PA-BD₄-AA₃ and cyclic PA₂-BD₃-AA, were only identified in juice samples after FPSE extraction. Besides, in order to quantify the compounds identified, an isolation procedure for PLA oligomers was carried out. Two oligomers were isolated: cyclic (LA)₆ and linear HO-(LA)₄-H, both with a purity higher than 90% (LA: lactic acid). The highest concentration value was found for the cyclic oligomer [AA-BD]₂, that showed 22.63 μg g^-1 in 3% acetic acid and 19.64 μg g^-1 in juice. The concentration of the total amount of remaining oligomers was below 7.56 μg g^-1 in 3% acetic acid as well as in juice.

Impacts of Plastic Pollution on Ecosystem Services, Sustainable Development Goals, and Need to Focus on Circular Economy and Policy Interventions

Plastic pollution is ubiquitous in terrestrial and aquatic ecosystems. Plastic waste exposed to the environment creates problems and is of significant concern for all life forms. Plastic production and accumulation in the natural environment are occurring at an unprecedented rate due to indiscriminate use, inadequate recycling, and deposits in landfills. In 2019, the global production of plastic was at 370 million tons, with only 9% of it being recycled, 12% being incinerated, and the remaining left in the environment or landfills. The leakage of plastic wastes into terrestrial and aquatic ecosystems is occurring at an unprecedented rate. The management of plastic waste is a challenging problem for researchers, policymakers, citizens, and other stakeholders. Therefore, here, we summarize the current understanding and concerns of plastics pollution (microplastics or nanoplastics) on natural ecosystems. The overall goal of this review is to provide background assessment on the adverse effects of plastic pollution on natural ecosystems; interlink the management of plastic pollution with sustainable development goals; address the policy initiatives under transdisciplinary approaches through life cycle assessment, circular economy, and sustainability; identify the knowledge gaps; and provide current policy recommendations. Plastic waste management through community involvement and socio-economic inputs in different countries are presented and discussed. Plastic ban policies and public awareness are likely the major mitigation interventions. The need for life cycle assessment and circularity to assess the potential environmental impacts and resources used throughout a plastic product’s life span is emphasized. Innovations are needed to reduce, reuse, recycle, and recover plastics and find eco-friendly replacements for plastics. Empowering and educating communities and citizens to act collectively to minimize plastic pollution and use alternative options for plastics must be promoted and enforced. Plastic pollution is a global concern that must be addressed collectively with the utmost priority.

An Effective Package of Antioxidants for Avoiding Premature Failure in Polypropylene Random Copolymer Plastic Pipes under Hydrostatic Pressure and High Temperature

Pipes of polypropylene random (PP-R) copolymers are the best choice for hot- and cold-water networks. Validation of a severe test, accomplishing the ISO 1167 standard, is mandatory to assess their service lifetime expectancy. This work evaluates the behavior shown by three commercial pipes, either the original ones (new pipes) or after being subjected to a hydrostatic pressure test at elevated temperature (aged pipes). Several features with relevance for the final performance have been examined: crystalline characteristics, phase transitions in crystalline regions, effect of high temperature and pressure on these transitions, and oxidation induction time. Moreover, the presence of inorganic fillers, and the content of different antioxidants together with their depletion, have also been analyzed. Films from the new pipes were also prepared for replication of the different environments in order to achieve a better and complete understanding of the phase transitions in the crystalline regions and of the consumption of antioxidants. Distinct environments surrounded the inner and outer parts of the pipes exposed to the failure aging test at 110 °C: hot water and warm dry air, respectively. These features play a key role in the loss of additives and in the subsequent initiation of degradation. Even if the crystalline characteristics are appropriate in the polymeric matrix, the success of a pipe lies in the homogeneous dispersion of components for avoiding damage at interfacial properties, and in a correct package of antioxidants used in its formulation.

An optimization approach for fast, simple and accurate determination of indigo-carmine in food samples

This study report optimization of vortex-assisted natural deep eutectic solvent based liquid-phase microextraction (VA-NADES-LPME) for determination of indigo-carmine in some food samples by UV-Visible spectrophotometer. To ensure efficient extraction, nine different NADES were prepared and tested for the extraction of indigo-carmine. In order to increase extraction efficiency of indigo-carmine, the effects of VA-NADES-LPME variables and their interactions were optimized with central composite design. The optimized method exhibited a linear range between 10 and 900 ng mL^-1. Limit of detection, limit of quantification and enrichment factor were determined as 3.3 ng mL^-1, 10 ng mL^-1 and 135-fold, respectively. The applicability of the optimized method was investigated in selected food samples using the matrix-matching calibration curve. Using optimised experimental conditions (pH of 3.2, 75 µL of NADES-4, 285 µL of THF, and 4 min vortexing), satisfactory recovery results were found in the range of 95.9-104.2% with 1.4-3.7% of relative standard deviation. Finally, the optimized method was economical, simple, green, requires less laborious sampling, and provides superior accuracy and precision in trace-level analysis.

Food packaging's materials: A food safety perspective

Food packaging serves purposes of food product safety and easy handling and transport by preventing chemical contamination and enhancing shelf life, which provides convenience for consumers. Various types of materials, including plastics, glass, metals, and papers and their composites, have been used for food packaging. However, owing to consumers' increased health awareness, the significance of transferring harmful materials from packaging materials into foods is of greater concern. This review highlights the interactions of food with packaging materials and elaborates the mechanism, types, and contributing factors of migration of chemical substances from the packaging to foods. Also, various types of chemical migrants from different packaging materials with their possible impacts on food safety and human health are discussed. We conclude with a future outlook based on legislative considerations and ongoing technical contributions to optimization of food-package interactions.

Study on the influence of advanced treatment processes on the surface properties of polylactic acid for a bio-based circular economy for plastics

New biotechnological processes using microorganisms and/or enzymes to convert carbonaceous resources, either biomass or depolymerized plastics into a broad range of different bioproducts are recognized for their high potential for reduced energy consumption and reduced GHG emissions. However, the hydrophobicity, high molecular weight, chemical and structural composition of most of them hinders their biodegradation. A solution to reduce the impact of non-biodegradable polymers spread in the environment would be to make them biodegradable. Different approaches are evaluated for enhancing their biodegradation. The aim of this work is to develop and optimize the ultrasonication (US) and UV photodegradation and their combination as well as dielectric barrier discharge (DBD) plasma as pre-treatment technologies, which change surface properties and enhance the biodegradation of plastic by surface oxidation and thus helping bacteria to dock on them. Polylactic acid (PLA) has been chosen as a model polymer to investigate its surface degradation by US, UV, and DBD plasma using surface characterization methods like X-ray Photoelectron Spectroscopy (XPS) and Confocal Laser Microscopy (CLSM), Atomic Force Microscopy (AFM) as well as FT-IR and drop contour analysis. Both US and UV affect the surface properties substantially by eliminating the oxygen content of the polymer but in a different way, while plasma oxidizes the surface.

Leaching and extraction of additives from plastic pollution to inform environmental risk: A multidisciplinary review of analytical approaches

Plastic pollution is prevalent worldwide and has been highlighted as an issue of global concern due to its harmful impacts on wildlife. The extent and mechanism by which plastic pollution effects organisms is poorly understood, especially for microplastics. One proposed mechanism by which plastics may exert a harmful effect is through the leaching of additives. To determine the risk to wildlife, the chemical identity and exposure to additives must be established. However, there are few reports with disparate experimental approaches. In contrast, a breadth of knowledge on additive release from plastics is held within the food, pharmaceutical and medical, construction, and waste management industries. This includes standardised methods to perform migration, extraction, and leaching studies. This review provides an overview of the approaches and methods used to characterise additives and their leaching behaviour from plastic pollution. The limitations of these methods are highlighted and compared with industry standardised approaches. Furthermore, an overview of the analytical strategies for the identification and quantification of additives is presented. This work provides a basis for refining current leaching approaches and analytical methods with a view towards understanding the risk of plastic pollution.

Deep Dive into Plastic Monomers, Additives, and Processing Aids

A variety of chemical substances used in plastic production may be released throughout the entire life cycle of the plastic, posing risks to human health, the environment, and recycling systems. Only a limited number of these substances have been widely studied. We systematically investigate plastic monomers, additives, and processing aids on the global market based on a review of 63 industrial, scientific, and regulatory data sources. In total, we identify more than 10'000 relevant substances and categorize them based on substance types, use patterns, and hazard classifications wherever possible. Over 2'400 substances are identified as substances of potential concern as they meet one or more of the persistence, bioaccumulation, and toxicity criteria in the European Union. Many of these substances are hardly studied according to SciFinder (266 substances), are not adequately regulated in many parts of the world (1'327 substances), or are even approved for use in food-contact plastics in some jurisdictions (901 substances). Substantial information gaps exist in the public domain, particularly on substance properties and use patterns. To transition to a sustainable circular plastic economy that avoids the use of hazardous chemicals, concerted efforts by all stakeholders are needed, starting by increasing information accessibility.

Safety of Plastic Food Packaging: The Challenges about Non-Intentionally Added Substances (NIAS) Discovery, Identification and Risk Assessment

Several food contact materials (FCMs) contain non-intentionally added substances (NIAS), and most of the substances that migrate from plastic food packaging are unknown. This review aimed to situate the main challenges involving unknown NIAS in plastic food packaging in terms of identification, migration tests, prediction, sample preparation, determination methods and risk assessment trials. Most studies have identified NIAS in plastic materials as polyurethane adhesives (PU), polyethylene terephthalate (PET), polyester coatings, polypropylene materials (PP), multilayers materials, plastic films, polyvinyl chloride (PVC), recycled materials, high-density polyethylene (HDPE) and low-density polyethylene (LDPE). Degradation products are almost the primary source of NIAS in plastic FCMs, most from antioxidants as Irganox 1010 and Irgafos 168, following by oligomers and side reaction products. The NIAS assessment in plastics FCMs is usually made by migration tests under worst-case conditions using food simulants. For predicted NIAS, targeted analytical methods are applied using GC-MS based methods for volatile NIAS and GC-MS and LC-MS based methods for semi- and non-volatile NIAS; non-targeted methods to analyze unknown NIAS in plastic FCMs are applied using GC and LC techniques combined with QTOF mass spectrometry (HRMS). In terms of NIAS risk assessment and prioritization, the threshold of toxicological concern (TTC) concept is the most applied tool for risk assessment. Bioassays with sensitive analytical techniques seem to be an efficient method to identify NIAS and their hazard to human exposure; the combination of genotoxicity testing with analytical chemistry could allow the Cramer class III TTC application to prioritize unknown NIAS. The scientific justification for implementing a molecular weight-based cut-off (<1000 Da) in the risk assessment of FCMs should be reevaluated. Although official guides and opinions are being issued on the subject, the whole chain's alignment is needed, and more specific legislation on the steps to follow to get along with NIAS.

Screening of chemicals migrating from plastic food contact materials for oven and microwave applications by liquid and gas chromatography - Orbitrap mass spectrometry

Contamination of food with chemicals migrating from food contact materials (FCMs) is an important area of food safety. This study was aimed to investigate migration of chemicals from plastic FCMs used for microwave and conventional oven heating. Migration tests were conducted for samples of microwave trays, microwave oven bags, and oven bags. GC- and LC-Orbitrap mass spectrometry (MS) was used for non-targeted screening and identification of chemicals with mass error <5 ppm. A non-targeted identification approach was validated with isotopically labeled chemicals to establish acceptable criteria for identification of migrated compounds. A total of 74 migrated compounds were tentatively identified: 24 chemicals by GC-Orbitrap MS with electron ionization (EI), plus 35 and 19 by LC-Orbitrap MS electrospray ionization (ESI) with positive and negative polarities, respectively. Four migrated chemicals were identified by more than one instrumental analysis. Both intentionally added substances (IAS), i.e. additives used in the production of polymeric materials and plastics, and non-intentionally added substances (NIAS), i.e. derivatives and degradation/oxidation products of IAS, were identified among the migrated chemicals. The levels of 25 migrated chemicals were significantly different (p < 0.05) between microwave treatments and conventional oven treatments, where 20 migrants had higher levels for microwave compared with 5 for conventional oven treatments. For several identified chemicals, no previous reports on their migration from FCMs were found.

Overview of intentionally used food contact chemicals and their hazards

Food contact materials (FCMs) are used to make food contact articles (FCAs) that come into contact with food and beverages during, e.g., processing, storing, packaging, or consumption. FCMs/FCAs can cause chemical contamination of food when migration of their chemical constituents (known as food contact chemicals, FCCs) occurs. Some FCCs are known to be hazardous. However, the total extent of exposure to FCCs, as well as their health and environmental effects, remain unknown, because information on chemical structures, use patterns, migration potential, and health effects of FCCs is often absent or scattered across multiple sources. Therefore, we initiated a research project to systematically collect, analyze, and publicly share information on FCCs. As a first step, we compiled a database of intentionally added food contact chemicals (FCCdb), presented here. The FCCdb lists 12'285 substances that could possibly be used worldwide to make FCMs/FCAs, identified based on 67 FCC lists from publicly available sources, such as regulatory lists and industry inventories. We further explored FCCdb chemicals' hazards using several authoritative sources of hazard information, including (i) classifications for health and environmental hazards under the globally harmonized system for classification and labeling of chemicals (GHS), (ii) the identification of chemicals of concern due to endocrine disruption or persistence related hazards, and (iii) the inclusion on selected EU- or US-relevant regulatory lists of hazardous chemicals. This analysis prioritized 608 hazardous FCCs for further assessment and substitution in FCMs/FCAs. Evaluation based on non-authoritative, predictive hazard data (e.g., by in silico modeling or literature analysis) highlighted an additional 1411 FCCdb substances that could thus present similar levels of concern, but have not been officially classified so far. Lastly, for over a quarter of all FCCdb chemicals no hazard information could be found in the sources consulted, revealing a significant data gap and research need.

Tackling the toxics in plastics packaging

The widespread use of plastic packaging for storing, transporting, and conveniently preparing or serving foodstuffs is significantly contributing to the global plastic pollution crisis. This has led to many efforts directed toward amending plastic packaging’s end of life, such as recycling, or alternative material approaches, like increasingly using paper for food packaging. But these approaches often neglect the critical issue of chemical migration: When contacting foodstuffs, chemicals that are present in packaging transfer into food and thus unwittingly become part of the human diet. Hazardous chemicals, such as endocrine disrupters, carcinogens, or substances that bioaccumulate, are collectively referred to as “chemicals of concern.” They can transfer from plastic packaging into food, together with other unknown or toxicologically uncharacterized chemicals. This chemical transfer is scientifically undisputed and makes plastic packaging a known, and avoidable, source of human exposure to synthetic, hazardous, and untested chemicals. Here, I discuss this issue and highlight aspects in need of improvement, namely the way that chemicals present in food packaging are assessed for toxicity. Further, I provide an outlook on how chemical contamination from food packaging could be addressed in the future. Robust innovations must attempt systemic change and tackle the issue of plastic pollution and chemical migration in a way that integrates all existing knowledge.

The widespread use of plastic packaging for storing, transporting, and conveniently preparing or serving foodstuffs is significantly contributing to the global plastic pollution crisis. This Essay exhorts us to change the conversation about plastic packaging and address the chemicals that migrate into food.

Identification of 24 Unknown Substances (NIAS/IAS) from Food Contact Polycarbonate by LC-Orbitrap Tribrid HRMS-DDMS3: Safety Assessment

Twenty-four substances, mainly NIAS, have been tentatively identified in food contact polycarbonate through the application a new, fast, and automated analytical strategy for the investigation of unknowns in food contact materials. Most of the identified compounds were plasticizers, slip agents, antioxidants, and ultraviolet stabilizers and fragrances, and the majority of them have not been previously identified in PC food contact materials. The workflow setup includes an intelligent data acquisition applied using LC-Orbitrap Tribrid-HRMS (MS3), with an automated data processing using Compound DiscovererTM. To obtain a high confidence identification of unknown substances, a very strict criterion has been established, which comprises exact mass, isotopic profile, MS2 match, retention time, and MS3 match. To check for the safety of the migration from the food contact polycarbonate, a risk assessment was achieved using the threshold of the toxicological concern (TTC) approach. Except for the slip agent hexadecanamide, the compounds tentatively identified do not represent a risk.

Establishment of an Indirect Competitive Enzyme-Linked Immunosorbent Method for the Detection of Heavy Metal Cadmium in Food Packaging Materials

Heavy metals in food packaging materials have been indicated to release into the environment at slow rates. Heavy metal contamination, especially that of cadmium (Cd), is widely acknowledged as a global environment threat that leads to continuous growing pollution levels in the environment. Traditionally, the detection of the concentration of Cd relies on expensive precision instruments, such as inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). In this study, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on a specific monoclonal antibody was proposed to rapidly detect Cd. The half-inhibitory concentration and detection sensitivity of the anti-cadmium monoclonal antibody of the ic-ELISA were 5.53 ng mL-1 and 0.35 ng mL-1, respectively. The anti-Cd monoclonal antibody possessed high specificity while diagnosising other heavy metal ions, including Al (III), Ca (II), Cu (II), Fe (III), Hg (II), Mg (II), Mn (II), Pb (II), Zn (II), Cr (III) and Ni (II). The average recovery rates of Cd ranged from 89.03-95.81% in the spiked samples of packing materials, with intra- and inter-board variation coefficients of 7.20% and 6.74%, respectively. The ic-ELISA for Cd detection was applied on 72 food packaging samples that consisted of three material categories-ceramic, glass and paper. Comparison of the detection results with ICP-AES verified the accuracy of the ic-ELISA. The correlation coefficient between the ic-ELISA and the ICP-AES methods was 0.9634, demonstrating that the proposed ic-ELISA approach could be a useful and effective tool for the rapid detection of Cd in food packaging materials.

The use of ion mobility time-of-flight mass spectrometry to assess the migration of polyamide 6 and polyamide 66 oligomers from kitchenware utensils to food

Oligomers, are, in general, unknown components of the polymer. These oligomers can migrate from the polymer into the food and become a non-intentionally added substance to the food. In this work, ion mobility time-of-flight mass spectrometry has been used to identify oligomers migrating from kitchenware. The structure elucidation of oligomers from polyamide 6 and polyamide 66 was achieved through the analysis of accurate m/z values of adducts and collision cross section values of precursor ions together with high-energy fragmentation patterns. Additionally, a method to extract oligomers from sunflower oil, cooked beans, soup and whole milk has been developed. Extraction recoveries ranged from 87 to 102% and limits of detection were from 0.03 to 0.11 mg/kg. It was observed that the migration from kitchenware to real food was below the specified migration limit of 5 mg/kg. However, this limit was exceeded for food simulants, which therefore overestimated the oligomer migration.

Importance of profile of volatile and off-odors compounds from different recycled polypropylene used for food applications

Nowadays, polypropylene is one of the most common polymers used in the food packaging industry due to its good functionality and relatively low cost. Nevertheless, usage of plastic disposable packaging can be a generator of plastic pollution having negative environmental effects. A feasible solution for this issue would be to recycle. The polypropylene samples were submitted to two processes, forced contamination, and recycling, and they were analyzed by solid-phase microextraction gas chromatograph-olfactometry-mass spectrometry. 45 different volatile compounds were identified and 9 of them presented distinct odoriferous activities. Among them, two important markers were detected: diethyl phthalate (probably coming from the catalyst of PP polymerization, intentionally added substance (IAS)), and glycerine (a marker of non-intentionally added substances (NIAS)).

Food safety and quality assessment: comprehensive review and recent trends in the applications of ion mobility spectrometry (IMS)

Ion mobility spectrometry (IMS) is an analytical separation and diagnostic technique that is simple and sensitive and a rapid response and low-priced technique for detecting trace levels of chemical compounds in different matrices. Chemical agents and environmental contaminants are successfully detected by IMS and have been recently considered to employ in food safety. In addition, IMS uses stand-alone or coupled analytical diagnostic tools with chromatographic and spectroscopic methods. Scientific publications show that IMS has been applied 21% in the pharmaceutical industry, 9% in environmental studies and 13% in quality control and food safety. Nevertheless, applications of IMS in food safety and quality analysis have not been adequately explored. This review presents the IMS-related analysis and focuses on the application of IMS in food safety and quality. This review presents the important topics including detection of traces of chemicals, rate of food spoilage and freshness, food adulteration and authenticity as well as natural toxins, pesticides, herbicides, fungicides, veterinary, and growth promoter drug residues. Further, persistent organic pollutants (POPs), acrylamide, polycyclic aromatic hydrocarbon (PAH), biogenic amines, nitrosamine, furfural, phenolic compounds, heavy metals, food packaging materials, melamine, and food additives were also examined for the first time. Therefore, it is logical to predict that the application of the IMS technique in food safety, food quality, and contaminant analysis will be impressively increased in the future. HighlightsCurrent status of IMS for residues and contaminant detection in food safety.To assess all the detected contaminants in food safety, for the first time.Identified IMS-related parameters and chemical compounds in food safety control.

Oligomers: Hidden sources of bisphenol A from reusable food contact materials

A recent European Regulation further restricted the use of bisphenol A in food-contact materials, reducing its limit of migration. However, all analytical systems of control are aimed at identifying and quantifying the molecules of this monomer without taking in consideration the possible presence of its oligomers, species originating from material degradation and able to follow an in-vivo hydrolysis providing bisphenol A generation. Thus, the presence of oligomers of polycarbonate deriving by unreacted species or polymer degradation can be considered a hidden source of several bisphenol A units, that remains outside the control of legislation and should be considered of high concern. This work was focused on the identification and the description of kinetics of release of different molecules migrating from polycarbonate food contact materials to simulants and to a model food sample such as melted chocolate. Analyses were performed by UHPLC system coupled to a Q-Exactive mass spectrometer. Targeted and untargeted analysis through data dependent acquisition mode allowed to detect the occurrence of several species deriving from polycarbonate, and permitted to investigate the polymer degradation pattern and explore the correlation of the recorded amounts of each product with age, hours of usage, and washing cycles of the plastic items.

Development and validation of an UHPLC-qTOF-MS method for the quantification of cyclic polyesters oligomers in pasta by applying a modified QuEChERS clean-up

An Ultra High-Performance Liquid chromatography method quadruple time-of-flight mass spectrometry has been developed for the analysis of 11 cyclic polyesters oligomers, following a modified QuEChERS clean-up with alumina/primary secondary amine, in pasta. Target analytes were polyethylene terephthalate (PET) 1^st series cyclic dimer to heptamer, polybutylene terephthalate (PBT) dimer to pentamer and a polyurethane oligomer. Standard addition method was applied for the calibration, and the limits of quantification ranged from 3.2 to 17.2 ng g^-1. Recoveries ranged from 86.4 to 109.8%, RSDs were lower than 12% for all analytes, and matrix effect never exceeded ± 2.5%. The method was successfully applied to real commercial pasta samples, where the PET 1^st series cyclic trimer was the most abundant oligomer, being found in all tested samples. The 1^st series PET cyclic dimer and tetramer, as well as 1,4,7-trioxacyclotridecane-8,13-dione, were found in considerable amounts. Traces of the 2^nd and 3^rd series PET cyclic dimers were also found.

Application of chromatographic analysis for detecting components from polymeric can coatings and further determination in beverage samples

Major type of internal can coating used for food and beverages is made from epoxy resins, which contain among their components bisphenol A (BPA) or bisphenol A diglycidyl ether (BADGE). These components can be released and contaminate the food or beverage. There is no specific European legislation for coatings, but there is legislation on specific substances setting migration limits. Many investigations have paid attention to BPA due to its classification as endocrine disruptor, however, few studies are available concerning to other bisphenol analogues that have been used in the manufacture of these resins. To evaluate the presence of this family of compounds, ten cans of beverages were taken as study samples. Firstly, the type of coating was verified using an attenuated total reflectance-FTIR spectrometer to check the type of coating presents in most of the samples examined. A screening method was also performed to investigate potential volatiles from polymeric can coatings of beverages using Purge and Trap (P&T) technique coupled to gas chromatography with mass spectrometry detection (GC-MS). Moreover, a selective analytical method based on high performance liquid chromatography with fluorescence detection (HPLC-FLD) for the simultaneous identification and quantification of thirteen compounds including bisphenol analogues (BPA, BPB, BPC, BPE, BPF, BPG) and BADGEs (BADGE, BADGE.H₂O, BADGE.2H₂O, BADGE.HCl, BADGE.2HCl, BADGE.H2O.HCl, cyclo-di-BADGE) in the polymeric can coatings and in the beverage samples was applied. In addition, a liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) method was optimized for confirmation purposes. The method showed an adequate linearity (R² >0.9994) and low detection levels down to 5 µg/L. Cyclo-di-BADGE was detected in all extracts of polymeric coatings. The concentrations ranged from 0.004 to 0.60 mg/dm². No detectable amounts of bisphenol related compounds were found in any of the beverage samples at levels that may pose a risk to human health, suggesting a low intake of bisphenols from beverages.

A recycler's perspective on the implications of REACH and food contact material (FCM) regulations for the mechanical recycling of FCM plastics

This manuscript provides an overview of the legislative requirements for the use of mechanical recycled plastics in articles placed on the EU market, as seen from the perspective of a plastics recycler. The first part reviews the main principles included in the overarching legislation on Registration, Evaluation, Authorisation and Restrictions of Chemicals (REACH) and to what extent these are applicable for mechanical recyclers of plastics. The interactions between REACH and the Waste Framework Directive (WFD) is discussed, as well as the difficulties for recyclers to comply with certain REACH requirements. In a second part, the focus is moved to the use of recycled plastics as Food Contact Material (FCM). The scope of the different applicable EU FCM regulations is inventorised as well as the key legislative principles involved. A final section is dedicated to the discussion on the authorisation of recycling processes under the FCM regulation and the practical challenges involved for the effective introduction of FCMs containing recycled plastics. Altogether it could be concluded that the complexity of the different legal perspectives, a lack of communication and transparency within the plastic value chain together with technical challenges related to recycling processes have been hindering the effective uptake of recycled plastic FCM (with the exception for bottle PET). The development of targeted solutions across the entire value-chain, taking into account different perspectives in terms of legislation and health protection, economic growth and technical innovations, will be crucial in achieving a circular economy for plastics, including recycled plastics for FCM.

An overview of chemical contaminants and other undesirable chemicals in alcoholic beverages and strategies for analysis

The presence of chemical contaminant in alcoholic beverages is a widespread and notable problem with potential implications for human health. With the complexity and wide variation in the raw materials, production processes, and contact materials involved, there are a multitude of opportunities for a diverse host of undesirable compounds to make their way into the final product-some of which may currently remain unidentified and undetected. This review provides an overview of the notable contaminants (including pesticides, environmental contaminants, mycotoxins, process-induced contaminants, residues of food contact material [FCM], and illegal additives) that have been detected in alcoholic products thus far based on prior reviews and findings in the literature, and will additionally consider the potential sources for contamination, and finally discuss and identify gaps in current analytical strategies. The findings of this review highlight a need for further investigation into unwanted substances in alcoholic beverages, particularly concerning chemical migrants from FCMs, as well as a need for comprehensive nontargeted analytical techniques capable of determining unanticipated contaminants.

Evaluation of a panel of spermatological methods for assessing reprotoxic compounds in multilayer semen plastic bags

The increase of fertility performance in sows is one of the biggest achievements in pig production over the last 30 years. Nevertheless, pig farms using artificial insemination (AI) repeatedly experienced in recent year’s fertility problems with dramatic consequences due to toxic compounds from plastic semen bags. In particular, bisphenol A diglycidyl-ether (BADGE) present in multilayer plastic bags can leach into the semen and could affect the functionality of the spermatozoa. Former studies could not find any alterations in spermatozoa based on the exposure to BADGE. The aim of the study was to evaluate effects of BADGE on boar spermatozoa using an extended panel of spermatological methods. In spring 2019, a large drop in farrowing rates from 92.6 ± 2.3% to 63.7 ± 11.1% in four sow farms in Croatia was detected. In migration studies, BADGE could be identified as a causal toxic compound and leached into the extended semen in concentration of 0.37 ± 0.05 mg/L. Detailed spermatological studies showed that significant predictors for effects on spermatozoa were different levels of motility and kinematic data after a prolonged storage time, thermo-resistance test (prolonged incubation time), mitochondrial activity, membrane integrity and fluidity. No serious effects were observed for sperm morphology and DNA fragmentation. These results provide new insights into the development of a new quality assurance concept for a detailed spermatological examination during testing of plastic materials for boar semen preservation. It could be shown that boar spermatozoa are an excellent biosensor to detect potential toxicity and fertility-relevant compounds.

Mycotoxins Analysis in Cereals and Related Foodstuffs by Liquid Chromatography-Tandem Mass Spectrometry Techniques

In the entire world, cereals and related foodstuffs are used as an important source of energy, minerals, and vitamins. Nevertheless, their contamination with mycotoxins kept special attention due to harmful effects on human health. The present paper was conducted to evaluate published studies regarding the identification and characterization of mycotoxins in cereals and related foodstuffs by liquid chromatography coupled to (tandem) mass spectrometry (LC-MS/MS) techniques. For sample preparation, published studies based on the development of extraction and clean-up strategies including solid-phase extraction, solid-liquid extraction, and immunoaffinity columns, as well as on methods based on minimum clean-up (quick, easy, cheap, effective, rugged, and safe (QuEChERS)) technology, are examined. LC-MS/MS has become the golden method for the simultaneous multimycotoxin analysis, with different sample preparation approaches, due to the range of different physicochemical properties of these toxic products. Therefore, this new strategy can be an alternative for fast, simple, and accurate determination of multiclass mycotoxins in complex cereal samples.

Non-targeted analysis and risk assessment of non-volatile compounds in polyamide food contact materials

Small molecules in food contact materials may migrate into food during their contact. To extensively analyze the migrants, non-targeted screening is needed to detect the migrants. The migrants' detection is difficult because of the complexity and the trace amount of the migrants. In this work, the dissolution precipitation method was used to extract small molecules in Polyamide (PA) kitchenware. The extract solutions were screened by ultra-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (UPLC-QTOF-MS) for non-targeted analysis and 64 different small molecules in materials were identified through the screening of a self-built database. Then, migration tests were performed to analyze migrants in food simulants. It suggests that the abundance of PA oligomers was the highest in migrants. The risk assessment of migrants revealed that the exposure of most migrants was at a safer level unlike the exposure of PA oligomers that exceeded their threshold of toxicological concern (TTC).

Ambient mass spectrometry as a tool for a rapid and simultaneous determination of migrants coming from a bamboo-based biopolymer packaging

New bamboo-based biopolymers are used as food packaging materials, but it must be evaluated to ensure consumers safety. In this study, migration from a commercial bamboo-based biopolymer to ethanol 10% (v/v), acetic acid 3% (w/v) and ethanol 95% (v/v) was studied. The migrants were determined from three different perspectives. Volatile and semi-volatile compounds were analyzed by gas chromatography-mass spectrometry (GC-MS). Twenty-five compounds were detected. In addition, a number of phytosterols were detected in ethanol 95%. Non-volatile compounds were identified and quantified by ultra-performance liquid chromatography coupled to time-of-flight mass spectrometry (UPLC-Q/ToF). Twelve non-volatile compounds were detected in migration solutions, mainly melamine and its derivatives, coming from polymer resins present in the biopolymer. Melamine migration was higher than 50 mg/Kg in the third sequential migration test. Finally, the migration samples were analyzed by DART-SVP (direct analysis in real time coupled to standardized voltage and pressure). This methodology was able to detect simultaneously the main volatile and non-volatile migrants and their adducts in a very rapid and effective way and is shown as a promising tool to test the safety and legal compliance of food packaging materials.

Permanently Positively Charged Stable Isotope Labeling Agents and Its Application in the Accurate Quantitation of Alkylphenols Migrated from Plastics to Edible Oils

A new permanently positively charged stable isotope labeling (SIL) agent pair, 4-(((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)-N,N,N-trimethylbenzenaminium iodide(DPTBA) and its deuterated counterpart d₃-DPTBA, was designed and synthesized. The SIL agents were applied to the liquid chromatography-tandem mass spectrometry analysis of alkylphenols. Light labeled standards and heavy labeled samples were mixed and analyzed simultaneously. Matrix effect which mainly occurred during the ionization process was minimized because of the identical ionization processes between samples and standards. Meanwhile, derivatization made alkylphenols be positively charged, and thus the sensitivity was enhanced. The limits of detection were in the range of 1.5-1.8 ng/L, and the limits of quantitation were in the range of 4.8-6.1 ng/L. The developed method was applied to analyze alkylphenols migrated from plastics to edible oils. The recoveries for all analytes were in the range of 88.6-95.3%, while the matrix effects for all analytes were in the range of 96.2-99.6%.

Non-intentionally added substances (NIAS) in recycled plastics

The demand for high quality recycled polymers in the European plastic industry is on the increase, likely due to the EU's Plastic Strategy intended to implement the circular economy model in this sector. The problem is that there is not enough recycled plastic in the market. In terms of volume, post-consumer plastic waste could be key to meet the current and future demand. Nevertheless, a high level of contamination originated during the product's life cycle restricts its use. The first step to change this must be identifying the undesired substances in post-consumer plastics and performing an effective risk assessment. The acquired knowledge will be fundamental for the development of innovative decontamination technologies. In this study, 134 substances including volatile and semi-volatile compounds have been identified in recycled LDPE and HDPE from domestic waste. Headspace and solvent extraction followed by GC/MS were used. The possible origin of each substance was studied. The main groups were additives, polymer and additives breakdown products, and contamination from external sources. The results suggest that recycled LDPE contains a broader number of additives and their degradation products. Some of them may cause safety concerns if reused in higher added value applications. Regarding recycled HDPE, the contaminants from the use phase are predominant creating problems such as intense odors. To reduce the number of undesired substances, it is proposed to narrow the variety of additives used in plastic manufacturing and to opt for separate waste collection systems to prevent cross-contamination with organic waste.

Chemical Migration from Beverage Packaging Materials—A Review

The packaging of a beverage is an essential element for customer convenience and the preservation of beverage quality. On the other hand, chemical compounds present in the packaging materials, either intentionally added or non-intentionally, may be transferred to the food. With a huge variety of materials used in the production, beverage packaging requires safety assessments with respect to the migration of packaging compounds into the filled beverages. The present article deals with potential migrants from different materials for beverage packaging, including PET bottles, glass bottles, metal cans and cardboard multilayers. The list of migrants comprises monomers and additives, oligomers or degradation products. The article presents a review on scientific literature and summarizes European food regulatory requirements. The review shows no evidence of critical substances migrating from packaging into beverages. Testing the migration in real beverages during and at the end of the shelf life shows compliance with the specific migration limits. Accelerated testing using food simulants, however, shows higher migration in some cases, especially at high temperatures in ethanolic simulants. For some migrants, more realistic testing conditions should be applied in order to show compliance with their specific migration limits.

Influence of nonylphenol from multilayer plastic films on artificial insemination of sows

Artificial insemination is common practice in mass livestock farming. Recently, it was shown that chemicals leaching from multilayer plastic bags affect the fertility of boars, although common quality tests did not show any impact on the sperm. It is not clear whether this incidence was a single case or whether it could be a systematic problem. Therefore, we studied six multilayer plastic bags. A total of 49 compounds were found, but most of them were at very low intensity. Nonylphenols in the range of 19-99 μg/g plastic were found. Migration tests using water and 10% ethanol as simulants, to mimic the behavior of semen with the extender, were performed. The most interesting migrants in terms of potential reprotoxicity were identified as nonylphenols. The identification in depth demonstrated the presence of 10 isomers of nonylphenol with a total concentration range between 16 to 58 μg/Kg simulant, among other migrants at lower concentration. The influence of these nonylphenols and their maximum tolerable concentration in direct contact with semen from boars was studied. Motility, viability, mitochondrial activity and acrosomes reacted were significantly affected at 10 mg/Kg of nonylphenols in contact with the sperm, but in vitro penetration rate was significantly decreased with only 2 mg/Kg. Insight into the mode of action is also provided.