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

Dr Steven Brennan
Dr Steven Brennan
3 min readAI-drafted, expert reviewed
EFSA logo

Key takeaway

What This Development Means

EFSA is consulting on revising and possibly merging its guidance on Weight of Evidence and Biological Relevance. The update seeks to improve usability, integrate alternative data sources, and harmonise with EU chemical safety goals, impacting regulators, industry, and policymakers alike.

What is EFSA’s Weight of Evidence guidance?

The Weight of Evidence guidance outlines how multiple data sources should be systematically assembled, assessed, and integrated to support regulatory decisions in food and chemical safety. It includes criteria for evaluating data reliability, relevance, and consistency.

Why is the guidance on Biological Relevance being revised?

The current biological relevance guidance lacks detailed, practical direction and overlaps with EFSA’s Weight of Evidence processes. The revision aims to improve clarity, integrate new scientific approaches like NAMs, and potentially streamline both into a single, cohesive document.

Source basis: https://connect.efsa.europa.eu/RM/a0lTk000005oHIv

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.

Get weekly regulatory updates:

Related Articles

Join 3,500+ professionals staying ahead

Subscribe to Foresight Weekly for expert-picked regulatory developments across chemicals, sustainability, product safety, ESG, and HSE.

Free forever. Unsubscribe anytime.

Read by professionals at

Boeing
AstraZeneca
Siemens
PepsiCo
SpaceX