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.

Two recent studies have proposed new methods to detect the presence of nanoparticles in food and cosmetics. The first study suggests a two-step approach to detect the banned food additive E 171. This involves screening for elemental titanium, followed by detecting nano-sized titanium dioxide. The second study used a quick screening tool to identify the presence of seven different nanoparticles in facial cosmetics. However, both methods have only been partially validated, and further improvements are required. There is a lack of reliable data on background titanium concentrations in food. A lack of reference matrices with known amounts of nanoparticles in consumer products is another challenge that needs to be addressed.

The use of Artificial Intelligence (AI) applications is quickly increasing and has the potential to revolutionize chemical risk assessment. For predicting the toxicity of nanomaterials, current models only work for relatively simple nanomaterials. There is a need to anticipate current developments and strategies to prepare for future AI implementation in chemical regulation.

Researchers from the EU Graphene Flagship have highlighted the complexity of assessing the safety of graphene and related materials. Such assessment requires detailed knowledge of safety-related physicochemical properties and the development of harmonised test methods. These lessons must receive ample attention in future innovation programmes on new materials.

By 2023, two European research projects related to the Malta Initiative were completed: Gov4Nano and NanoHarmony. These projects provided scientific support to thirteen OECD projects aimed at developing or modifying OECD Test Guidelines or Guidance Documents. However, more work is needed to finalise the OECD documents. The Malta Initiative has also identified further needs for harmonised test methods for future (advanced) materials and animal-free safety testing. The NanoHarmony White Paper guides on how to continue developing these test methods. However, it is uncertain how to identify and address future needs in the absence of resources for funding.

The safety of fullerenes in cosmetic products is uncertain, according to the EU Scientific Committee on Consumer Safety (SCCS). The information provided by the Notifier on the possible genotoxicity of fullerenes and other concerns was insufficient. The European Commission has recently proposed a new rule requiring the industry to provide additional data in the short term. If the industry fails to do so, fullerenes will be banned for use in cosmetic products, like other nanomaterials.