Integrated approaches to testing and assessment (IATAs) can optimise testing strategies and minimise the use of test animals in chemical risk assessment. Recently, aquatic IATAs have been developed that efficiently integrate the limited information on the fate and effects of nanomaterials. This approach can significantly improve the risk assessment of nanomaterials. However, IATAs are not yet widely accepted or implemented in regulatory risk assessment.

Integrated approaches to support grouping and read-across

Grouping and read-across approaches for nanomaterials are used to extrapolate data from data-rich source materials to a similar nanomaterial of interest that lacks data. If nanomaterials can be grouped according to their “similarity”, data or models that have been generated for source materials can be used to assess data-poor nanomaterials. Justification of the grouping and the read-across approaches is essential to ensure their validity.

Integrated Approaches to Testing and Assessment (IATAs) are flexible approaches to chemical safety assessment. They are based on the integration of data derived from multiple methods and sources. Although IATAs are currently not widely accepted in regulatory risk assessment, they can help support the grouping and read-across approaches for nanomaterials.

IATAs for aquatic systems

IATAs have been used in regulatory contexts to support the collection and integration of relevant existing information. For instance, a combination of data from different tests on the skin-sensitising potential of chemicals have been used. IATAs can also help support grouping and read-across approaches and identify data gaps.

For nanomaterials, it is difficult to assess the impact of small changes in physicochemical properties on their fate and effect. IATAs for such an assessment are generally lacking. Recently, however, an efficient testing strategy was reported. This aquatic IATA combines dissolution, dispersion stability, and chemical transformations with the relative contribution to toxicity of the nanoparticle and its dissolved component(s). The publication provides examples and identifies guidance on tiered testing approaches.

Reflections by RIVM

The specific IATA discussed here is the first example of the successful integration of data and knowledge on the fate and effect-related properties of metallic nanomaterials. This approach improves testing strategies and reduces the use of test animals as much as possible.

The IATA is the first of its kind to focus on environmental risks. It can significantly improve the efficiency of environmental risk assessment of nanomaterials. The IATA’s focus on the unique properties of metallic nanomaterials that affect the environmental fate and effects makes it an effective tool. It fits well within the current approaches towards grouping and read-across in chemical risk assessment.