Chemical simplification and tracking in plastics

Plastic pollution experts make a case for addressing toxic additives, unintentionally added substances, and contaminants in plastics. They point out that current regulations fail to require plastic producers to track or make available information on harmful chemicals in plastics. For these reasons, the experts say that before recycling can be considered as part of the approach to end plastic pollution, especially if it becomes part of the UN Plastics Treaty, plastic’ chemicals must be simplified through a major reduction of the expansive amount of chemicals used in plastics production.

Scientists find that some compostable plastics have similar or even higher levels of toxicity than plastic products, when it comes to chemical additives. These findings suggest that additives in bioplastics and other plant-based compostables must be carefully evaluated before use.

Abstract: This study investigates the toxicity of methanolic extracts obtained from compostable plastics (BPs) and conventional plastics (both virgin and recycled). Additionally, it explores the potential influence of plastic photodegradation and composting on toxic responses using a battery of in vitro assays conducted in PLHC-1 cells. The extracts of BPs, but not those of conventional plastics, induced a significant decrease in cell viability (<70%) in PLHC-1 cells after 24 h of exposure. Toxicity was enhanced by either photodegradation or composting of BPs. Extracts of conventional plastics, and particularly those of recycled plastics, induced 7-ethoxyresorufin-O-deethylase (EROD) activity and micronucleus formation in exposed cells, indicating the presence of significant amounts of CYP1A inducers and genotoxic compounds in the extracts, which was enhanced by photodegradation. These findings highlight the importance of investigating the effects of degradation mechanisms such as sunlight and composting on the toxicity of BPs. It is also crucial to investigate the composition of newly developed formulations for BPs, as they may be more harmful than conventional ones.

This research commentary shows that microplastics and nanoplastics are accumulating in fish that ingest plastic particles as or along with food. Observed impacts of plastic particle ingestion in fish include intestinal blockage, physical injury, change in behavior, and other major health issues.

Abstract: The European Marine Strategy Framework Directive and the United States Microbead Free Waters Act are credited for being ambitious in their goals for protecting the marine environment from microplastics pollution. As a result, the microplastic pollution of marine environments and the incidence of microplastic ingestion by fish is rapidly receiving an increase in overdue attention. This commentary summarizes recent discoveries regarding the potential negative effects of micro- and nanoplastic ingestion by fish. Analysis shows that the occurrence of microplastics in the gastrointestinal tract of fish is ephemeral, with low accumulation potential in the gastrointestinal tract, although translocation to the liver may occur. Nevertheless, the total load of micro- and nanoplastics that will pass through the gastrointestinal tract of a fish in its lifetime is likely high and will keep increasing in the future. This may pose a risk because there is evidence that micro- and nanoplastic ingestion can interfere with fish health. Observed effects of microplastics ingestion include (but are not necessarily limited to) intestinal blockage, physical damage, histopathological alterations in the intestines, change in behavior, change in lipid metabolism, and transfer to the liver.

Lead has been detected in a wide range of consumer products, including those made of or with plastic. As plastics are recycled, toxic lead is transferred into new consumer products and pollutes human bodies and the environment. Scientists propose that plastic pollution be classified as hazardous depending on its lead content and according to existing regulations on consumer plastics.

Abstract: X-ray fluorescence spectrometry has been employed to measure Pb in a wide range of consumer and environmental plastics, including food-packaging material, household goods, electronic casings, beach litter and agricultural waste. Results reveal high concentrations of Pb (>1000 mg kg−1) in historical items that are still in use or circulation (e.g. toys, construction plastics, wiring insulation) and variable, but generally lower concentrations in more recently manufactured articles. Analysis of Br, Cl and Cr, proxies for brominated flame retardants, polyvinyl chloride (PVC) and chromate pigments, respectively, suggests that as historical material is recycled, Pb from electronic plastics and pigments, but not PVC, is dispersed into a variety of newer products. Although most cases in the consumer sector comply with relevant EU Directives, some products that are non-compliant highlight shortfalls in regulations where recycling is involved and potential problems arising from the direct fashioning of industrial plastics into new consumer goods through attempts to be environmentally positive. The uncontrolled loss of historical and recycled plastics has also resulted in Pb contamination of the environment. Here, it is proposed that litter can be classified as hazardous depending on its Pb content and according to existing regulations that embrace consumer plastics.

This Synthesis Report (SYR) of the IPCC Sixth Assessment Report (AR6) summarizes the state of knowledge of climate change, its widespread impacts and risks, and climate change mitigation and adaptation, based on the peer-reviewed scientific, technical and socio-economic literature since the publication of the IPCC’s Fifth Assessment Report (AR5) in 2014.

The assessment is undertaken within the context of the evolving international landscape, in particular, developments in the UN Framework Convention on Climate Change (UNFCCC) process, including the outcomes of the Kyoto Protocol and the adoption of the Paris Agreement. It reflects the increasing diversity of those involved in climate action.

Scientists chemically analyze 28 samples of recycled high density polyethylene (HDPE) collected from across regions of the Global South, along with a fresh sample of new HDPE. Their research shows the prevalence of certain chemicals commonly used in processing HDPE increase in recycled plastic, as well as pesticides, pharmaceuticals, industrial chemicals, and other plastic additives.

Abstract: Plastics are produced with a staggering array of chemical compounds, with many being known to possess hazardous properties, and others lacking comprehensive hazard data. Furthermore, non-intentionally added substances can contaminate plastics at various stages of their lifecycle, resulting in recycled materials containing an unknown number of chemical compounds at unknown concentrations. While some national and regional regulations exist for permissible concentrations of hazardous chemicals in specific plastic products, less than 1 % of plastics chemicals are subject to international regulation [1]. There are currently no policies mandating transparent reporting of chemicals throughout the plastics value chain or comprehensive monitoring of chemicals in recycled materials.

The dataset presented here provides the chemical analysis of 28 samples of recycled High-Density Polyethylene (HDPE) pellets obtained from various regions of the Global South, along with a reference sample of virgin HDPE. The analysis comprises both Target and Non-Targeted Screening approaches, employing Liquid Chromatography-High-Resolution Mass Spectrometry (LC-HRMS) and Gas Chromatography-High-Resolution Mass Spectrometry (GC-HRMS). In total, 491 organic compounds were detected and quantified, with an additional 170 compounds tentatively annotated. These compounds span various classes, including pesticides, pharmaceuticals, industrial chemicals, plastic additives.

The results highlight the prevalence of certain chemicals, such as N-ethyl-o-Toluesulfonamide, commonly used in HDPE processing, found in high concentrations. The paper provides a dataset advancing knowledge of the complex chemical composition associated with recycled plastics.