Results of a round-robin exercise on read-across

Area of Science:

• Environmental chemistry and toxicology
• Computational toxicology and cheminformatics

Background:

• Regulatory assessments increasingly rely on in silico methods and read-across for chemical hazard evaluation.
• The CALEIDOS LIFE project organized a collaborative exercise to evaluate these approaches.
• Standardized methodologies are crucial for consistent and reliable hazard predictions.

Purpose of the Study:

• To assess the hazard of substances using in silico methods and read-across approaches.
• To evaluate the consistency and justification of predictions across different participants.
• To understand how chosen methodologies influence hazard assessment outcomes for mutagenicity, bioconcentration, and fish acute toxicity.

Main Methods:

• A round-robin exercise involving multiple participants.
• Application of in silico tools and read-across strategies for hazard assessment.
• Evaluation of three toxicological endpoints: mutagenicity, bioconcentration factor (BCF), and fish acute toxicity (FAT).

Main Results:

• Participants applied various in silico tools and read-across justifications for hazard predictions.
• The exercise highlighted the importance of the reasoning process over final predictions.
• Data collected provides insights into the practical application and variability of computational methods.

Conclusions:

• The justification behind in silico and read-across predictions is critical for robust chemical hazard assessment.
• Understanding methodological choices is key to interpreting and improving predictive toxicology.
• Further refinement of guidelines for applying these methods in regulatory contexts is warranted.