Chemical selection for the Thyroid Validation Study coordinated by EURL ECVAM and involving EU-NETVAL laboratories

Area of Science:

• Endocrinology
• Toxicology
• Chemical Safety Assessment

Background:

• Thyroid hormone disruption poses risks to human health.
• Non-animal testing methods are crucial for evaluating endocrine disruptors.
• Existing methods require validation for reliability and mechanistic understanding.

Purpose of the Study:

• To validate non-animal methods for identifying thyroid hormone disruptors.
• To assess the mechanistic relevance of selected methods.
• To establish a robust chemical set for method validation.

Main Methods:

• A stepwise chemical selection process using literature review and expert judgment.
• Development of standard operating procedures for selected methods.
• Mechanistic evaluation of methods using a diverse set of 30 validation chemicals.

Main Results:

• A curated set of 30 chemicals was established for method validation.
• The study ensured broad chemical space representation and mechanistic coverage.
• Insights into the mechanistic relevance of non-animal methods were gained.

Conclusions:

• Validated non-animal methods will enhance the identification and evaluation of endocrine disruptors.
• The findings support regulatory decision-making and the adoption of alternative testing strategies.
• This research contributes to a multifaceted understanding of thyroid hormone action and disruption.