Structural alerts for the identification of bioaccumulative compounds

Area of Science:

• Environmental Chemistry
• Toxicology
• Regulatory Science

Background:

• The European Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) regulation mandates bioaccumulation assessments.
• Bioconcentration factor (BCF) is a key parameter for evaluating bioaccumulation.
• Quantitative structure-activity relationships (QSARs) and a weight-of-evidence approach are encouraged for chemical assessment.

Purpose of the Study:

• To develop a novel decision-support system for identifying substances with bioaccumulation potential using structural alerts.
• To integrate structural alerts with existing data sources to reduce assessment uncertainty.
• To enhance the applicability and interpretability of bioaccumulation assessments.

Main Methods:

• Identification of structural alerts based on fish bioconcentration factor (BCF) data for 779 chemicals.
• Validation of the approach on 278 external molecules.
• Development of an easy-to-use workflow for the decision-support system.

Main Results:

• The developed system successfully identified 77% of bioaccumulative chemicals.
• The structural alert approach demonstrated competitiveness with complex QSAR models.
• The identified alerts directly correlate with specific structural features, improving interpretability.

Conclusions:

• Structural alerts provide a valuable, interpretable tool for identifying bioaccumulation potential.
• This approach supports regulatory decision-making within a weight-of-evidence framework.
• The free, user-friendly workflow facilitates broader adoption in chemical risk assessment.