EFSA Seeks Feedback On Overhaul Of Weight Of Evidence And Biological Relevance Guidance

The European Food Safety Authority (EFSA) has launched a public consultation on a major update—and potential merging—of its 2017 guidance documents on the Weight of Evidence (WoE) and Biological Relevance. This consultation, open until 5 November 2025, invites input from stakeholders across the chemicals ecosystem, including risk assessors, regulators, and industry professionals.

The initiative aims to create a more coherent, applicable, and scientifically robust framework for evidence integration in chemical risk assessments. By addressing long-standing implementation challenges and incorporating recent scientific advances such as New Approach Methodologies (NAMs), EFSA seeks to modernise its regulatory tools in line with the EU’s Chemicals Strategy for Sustainability.

EFSA Proposes Structural And Content Revisions

EFSA’s scoping paper outlines two core proposals: revising the structure and content of the current guidance, and potentially merging the two into a single, harmonised document. The need stems from overlapping functions between WoE and biological relevance assessments, particularly when evaluating the applicability, reliability, and consistency of data—including alternative data sources such as read-across, in vitro methods, and biomarker-based evidence.

To enhance usability, EFSA suggests:

• Streamlining guidance with flowcharts and concise procedural steps,
• Providing updated case studies from recent EFSA opinions,
• Incorporating specific criteria for integrating NAMs and toxicokinetic modelling,
• Aligning the revised guidance with internal EFSA tools and international standards.

Implications For Regulators, Industry, And Policymakers

While the primary audience includes EFSA scientific staff and national risk assessors, the revised guidance will significantly influence regulatory submissions, product approvals, and chemical safety strategies across the EU. Risk managers and stakeholders from both public and private sectors stand to benefit from greater clarity and transparency in EFSA’s evidence evaluation methods.

If successful, the guidance could streamline compliance processes and reduce reliance on animal testing by facilitating broader acceptance of alternative data sources. However, stakeholders are urged to weigh in on whether merging the two documents would enhance or hinder clarity and usability.