OECD releases two new IATA case studies demonstrating frameworks for chemical safety assessment

The Organisation for Economic Co-operation and Development (OECD) has released two new Integrated Approaches to Testing and Assessment (IATA) case studies as part of its eleventh review cycle, coordinated under the Working Party on Hazard Assessment (WPHA). Both studies demonstrate applications of the Alternative Safety Profiling Algorithm (ASPA), a structured framework developed within the EU-funded RISK-HUNT3R project to integrate non-animal data and other evidence sources into chemical safety assessments. By illustrating how ASPA can be applied to different substances and regulatory questions, the studies contribute to the development of transparent, flexible, and scientifically robust approaches that can replace animal tests.

• OECD Series on Testing and Assessment No. 448: Case Studies for the Integrated Approaches for Testing and Assessment of propylparaben (PrP) from multiple sources using ASPA: This case study applies the ASPA framework to assess whether combined exposure to propylparaben from personal care products and consumer goods is safe for consumers. It integrates in silico and in vitro data to estimate levels at which propylparaben may cause adverse effects and compares these with estimated consumer exposure. The assessment concludes that the combined exposure is safe under the scenarios considered, consistent with an earlier IATA on propylparaben in cosmetics (OECD Series on Testing and Assessment No. 320). The study demonstrates how ASPA can support chemical safety assessments using non-animal methods and exposure information.
• OECD Series on Testing and Assessment No. 447: Case Studies for the Integrated Approaches for Testing and Assessment for Systemic Toxicity of Conazoles Using a Read-Across Approach: This case study applies the ASPA framework to predict the systemic toxicity of difenoconazole using a read-across approach based on non-animal data and existing in vivo data. It integrates chemical similarity analyses, in vitro assays, transcriptomics, and physiologically based kinetic (PBK) modelling to identify suitable source substances and derive toxicity estimates. The predicted lowest observed adverse effect levels (LOAELs) were within a two-fold range of the value predicted using animal tests, demonstrating the potential of using a read-across approach based on non-animal data and existing in vivo data to generate comparable toxicity estimates. The study also illustrates how ASPA can support transparent and structured chemical safety assessments.

For more information, please refer to the OECD webpage on Integrated Approaches to Testing and Assessment (IATA).