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.

Several OECD guidelines for testing chemicals have been updated to include nanospecific considerations, which are generally effective. Despite these efforts, challenges remain in standardising the testing of nanomaterials in water, as particles tend to clump together, leading to unstable dispersions and irreproducible results.

Nanoforms of fertilisers or biostimulants sprayed directly onto plant leaves may contribute to more sustainable agricultural practices. However, it needs to be clarified whether the current legislation and methodologies sufficiently addresses the nanospecific properties of these products when assessing the benefits and risks for crops, the environment, and human health.

Two recent reports reviewed existing New Approach Methodologies (NAMs). One focussed on the purpose of regulatory risk assessment and the other on in silico methods for the Safe-and-Sustainable-by-Design (SSbD) of nanomaterials.

The European Scientific Committee on Consumer Safety (SCCS) evaluated information on genotoxicity of titanium dioxide used in cosmetic products. This was triggered by previous similar concerns for food additive E 171 (titanium dioxide, TiO2).

The past few decades of managing the uncertain risks for human and environment associated with nanomaterials have provided crucial insights for ensuring the safe and sustainable development of advanced materials.