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.

The German Environment Agency (UBA) conducted a systematic literature review to identify advanced materials that are used in the energy transition. These advanced materials may pose potential risks to human health and the environment. To ensure that the energy transition itself does not create new health, environmental or social risks, it is necessary to carefully consider the safety and sustainability of these 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).