Integrated Approaches to Testing and Assessment.

Area of Science:

• Toxicology
• Chemical Safety Assessment
• Regulatory Science

Background:

• Traditional chemical assessments rely heavily on animal testing and standard toxicity tests.
• Integrated Approaches to Testing and Assessment (IATA) offer a flexible strategy integrating diverse evidence, including mechanistic and non-animal data.
• IATA utilizes weight-of-evidence, incorporating expert judgment, which presents challenges for full harmonization.

Purpose of the Study:

• To illustrate the differences between existing IATA in regulatory toxicology.
• To highlight ongoing international harmonization efforts for defined approaches.
• To explore the potential of defined approaches using multiple non-animal information sources.

Main Methods:

• Review of existing IATA frameworks in regulatory toxicology.
• Analysis of international activities focused on harmonizing defined approaches.
• Comparison of IATA flexibility with the structured nature of defined approaches.

Main Results:

• IATA, while flexible, are difficult to fully harmonize due to inherent expert judgment.
• Defined approaches, featuring fixed data interpretation procedures, show potential for harmonization.
• There is a divergence between the broad scope of IATA and the specific focus of harmonized defined approaches.

Conclusions:

• Full harmonization of IATA is hindered by their reliance on expert judgment.
• Defined approaches represent a harmonizable component of IATA, utilizing defined data sources and interpretation procedures.
• Future efforts should focus on harmonizing defined approaches to enhance regulatory consistency and efficiency in chemical safety assessment.