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.

Early4AdMa is an early awareness and action system for identifying emerging issues of advanced materials. Its first application on nanocarriers has revealed several potential issues for nanocarrier materials. These include the applicability of current regulations regarding nanocarriers. In various chemical domains this needs to be critically assessed in more detail. Further, research activities should focus on the carrier’s influence on the active ingredient. What happens to the carrier itself after its work is done also requires attention. Overall, the workshop results demonstrate that the Early4AdMa system may help to identify potential issues with safety, sustainability, and regulation. Provided that these issues are addressed through follow-up actions, this may help regulatory preparedness and contribute to safer materials.

Electronic waste (e-waste) is a valuable source of precious and rare metals. Recycling of e-waste is an essential step towards sustainability. Scientists are currently studying methods to convert the metals present in e-waste into nanoparticles. However, it is important to consider the possible risks associated with this process to maximise its positive environmental impact.

Danish researchers assessed recommendations for adjustments to legislation for nanomaterials published in 2004. While many of these recommendations were partly or fully met, some legislation still needs adjustments for nanomaterials. For example, the definition of nanomaterials differs between legislations. Additionally, instruments to measure nanomaterials and test methods require further development to meet regulatory requirements and enable enforcement. Advanced materials may pose additional challenges in risk assessment. The legislation amendments for nanomaterials may not necessarily identify potential hazards and risks for advanced materials.

Respirable rigid fibres are considered more hazardous than non-rigid fibres. However, there is currently no standardised method to measure fibre rigidity. A new approach uses techniques to identify changes at the molecular level in cells. This approach can distinguish between different types of carbonaceous materials. The researchers could tell the difference between rigid fibres, non-rigid fibres, and non-fibrous carbonaceous materials. For this they looked at which biological pathways were affected. This method will help group different types of fibres into hazard categories based on their rigidity.

Bioaccumulation assessment of nanomaterials cannot be done using the equilibrium partitioning method commonly used for organic chemicals. Therefore, the current guidance on bioaccumulation assessment is not suitable for nanomaterials. To address this issue, the OECD has proposed a tiered approach designed specifically for nanomaterials. This approach is tailored for metallic and metal oxide particles but can likely be extended to other advanced (nano)materials as well.