A recent study applied machine learning to investigate which physicochemical and experimental factors were most involved in genotoxicity of titanium dioxide (TiO2). The findings confirmed that exposure concentration, cell medium composition, and lysis temperature in the comet assay correlate with DNA damage. The identified correlations could provide valuable insights for standardizing this test. However, the study methods and findings are too limited to identify new parameters involved in genotoxicity. Also, the scope was not aimed at providing evidence on the genotoxicity of TiO2, and therefore the study has no direct relevance for the discussion on the carcinogenicity classification of TiO2 nanomaterials.

A recent review discusses the suitability of in vitro models for studying the intestinal uptake of nanomaterials. While Caco-2 cell models are widely recognised for studying chemical uptake, their suitability for nanomaterials is limited due to the complex physiological processes involved, prompting the need for more advanced co-culture models. Significant knowledge gaps remain, especially in standardising and assessing how well these models mimic human biology and relevant exposure scenarios. Currently, the first steps towards harmonization of new approach methodologies as a tool to predict intestinal uptake of nanomaterials are being taken.

Advancements in nanoscience over the past 25 years have significantly influenced fields like nanoelectronics, bionanotechnology, and nanophotonics, driving innovations in computing, healthcare, and energy. Two key publications celebrate these achievements while underscoring the necessity for robust safety governance frameworks to address health, environmental, and ethical concerns associated with nanomaterials. As the integration of nanotechnology into everyday life accelerates, understanding the risks and benefits of these materials becomes crucial, prompting a call for proactive, adaptive regulatory approaches and international collaboration.

A recent review highlights the potential of using common waste materials, such as fruit peels and food waste, for the sustainable synthesis of nanoparticles, utilizing their rich natural compounds as reducing and stabilizing agents. This green chemistry approach enhances production efficiency compared to traditional methods, offering significant economic and environmental benefits by using biomass waste streams and reducing raw material costs. Challenges remain regarding consistency, long-term safety, and scaling up production. There is a need for clear regulatory guidelines and standardised toxico¬logical evaluations which are improved to enable wider industrial adoption.

MXenes (pronounced maxenes) are a unique family of two-dimensional materials. Current regulatory frameworks struggle to effectively manage MXenes due to their distinct properties and lack of appropriate safety testing methods. The OECD's Early4AdMa methodology highlights the need for improved characterisation, toxicity testing, and greener production processes for titanium carbide MXenes, emphasising the limited data available on their health and environmental impacts. Proactive regulation and interdisciplinary collaboration are essential as MXenes move closer to commercialisation, ensuring that safety and sustainability considerations are incorporated into the development of advanced materials.

A recent review highlights the significant impact of dispersion methods on the outcomes of toxicity tests involving nanoparticles. The authors found that variations in dispersion methods, such as sonication settings and the composition of the dispersion medium, can affect the agglomerate particle size and, consequently, the toxicity of nanoparticles. The authors emphasise the need for better guidance, which has recently been published in the updated OECD guidance on sample preparation and dosimetry.

Cell-based assays have shown promise in predicting the lung toxicity of silica nanomaterials. Two different tests provided a ranking of the potential of different silica nanoparticles to cause persistent lung inflammation in rats. The research by the EU project SAbyNa demonstrated that cell tests can play a vital role in comparing the hazards of various candidate nanomaterials within a Safe and Sustainable by Design (SSbD) framework, aiding in the selection of safer materials during product development. Further development of cell testing is needed for other silica particles, (nano)materials and different exposure conditions.

The European Union’s Court of Justice recently upheld the General Court’s decision to cancel the classification of titanium dioxide (TiO2) particles, including nanoparticles, as a suspected human carcinogen. The classification was cancelled following successful appeals from manufacturers, producers and importers. An appeal to the General Court’s ruling by the EC and France was unsuccessful, and as a result, TiO2 is no longer classified as a carcinogen.

The NanoHarmony project emphasises the importance of standardising safety test methods to enhance their regulatory acceptance. It highlights the benefits of standardisation, such as showcasing the value of developers' work, expanding their networks, and improving safety testing. However, challenges include a lack of knowledge about the process, inconsistent funding, and the lengthy duration of method development and validation for regulatory acceptance. To address these issues, NanoHarmony has created resources like a white paper, training modules, and the OECD TG/GD Process Mentor to guide developers through the standardisation process.

The European Chemicals Industry Action Plan (CIAP) aims to strengthen the EU chemical sector while prioritising safety, sustainability, and climate goals. The plan includes proposed actions such as forming a Critical Chemicals Alliance, simplifying labelling rules, and introducing an Advanced Materials Act by the end of 2026 to foster innovation in materials essential for clean technology and the circular economy. However, the lack of clear definitions for "advanced" materials and the challenges in properly assessing their safety and lifecycle risks are a concern. This highlights the need for reliable data and established test methods and risk assessment methodologies targeted at advanced materials that allow navigating these complexities.