The European Food Safety Authority (EFSA) has announced a public consultation on its revised guidance concerning the Margin of Exposure (MoE) approach for chemicals that exhibit both genotoxic and carcinogenic properties. This initiative aims to update the 2005 guidance, addressing recent advancements in scientific understanding and analytical methodologies.
Background
EFSA's 2005 opinion introduced the MoE approach as a harmonised method for assessing the risks associated with genotoxic and carcinogenic substances in food and feed. This approach provided a structured way to prioritise substances for regulatory action based on a comparison between human exposure levels and reference points derived from animal studies.
Need for Revision
EFSA's Scientific Committee has recognised several challenges and limitations in the current MoE framework. These include increased detection of genotoxic chemicals due to improved analytical methods and a shift away from animal carcinogenicity studies due to animal welfare concerns. The updated guidance aims to address these issues, ensuring a more reliable and harmonised risk assessment process.
Proposed Revisions
The revised guidance will cover several key areas:
- State of the Art and Definitions:
- Clarification of definitions and terminologies related to the MoE, genotoxicity, and carcinogenicity.
- Review of international documents on MoE calculations and applications.
- Application of the MoE:
- Guidelines for applying the MoE to different species, considering their lifespan and relevance of endpoints.
- Methods for assessing chemical mixtures using the total MoE approach.
- Use of physiologically based kinetic modelling for internal MoE calculations.
- Calculation of the MoE:
- Recommendations on the most appropriate reference points for genotoxic chemicals, considering the latest dose-response modelling guidance.
- Guidelines for selecting and using genotoxicity data in MoE calculations.
- Interpretation of the MoE:
- Revised principles for interpreting MoE values, focusing on uncertainties and risk communication.
- Uncertainties and Other Issues:
- Discussion on uncertainties in the overall approach.
- Consideration of future developments, such as in vitro and in silico methodologies and biomarkers of effect.
Engagement and Timeline
EFSA is seeking feedback from stakeholders on the proposed revisions, work plan, and engagement activities. The scoping paper will be open for an eight-week public consultation period, ending on 6 September 2024. It is not possible to submit comments after this date. Following this, a series of workshops, public consultations, and webinars will be conducted to refine the guidance.
The drafting of the revised guidance is expected to commence in Q3/Q4 of 2024, with a timeline of 18-24 months for completion. The final guidance document will undergo a second public consultation before adoption and publication by EFSA's Scientific Committee.
