Initiatives to decrease redundancy in animal testing of pesticides.

Area of Science:

• Toxicology
• Risk Assessment
• Regulatory Science

Background:

• Current regulatory guidelines often mandate extensive toxicological studies.
• The necessity and impact of specific long-term studies, like the 12-month dog study and mouse cancer bioassays, warrant re-evaluation.
• Optimizing data requirements is crucial for efficient and effective risk assessment.

Purpose of the Study:

• To identify toxicological studies that can be removed from data requirements without affecting risk assessment quality.
• To evaluate the sensitivity and regulatory relevance of the 3-month versus 12-month dog studies.
• To assess the contribution of mouse cancer studies in regulatory decision-making.

Main Methods:

• Database evaluation of toxicological study sensitivity.
• Analysis of regulatory data to identify compounds where the 12-month dog study NOAEL was significantly lower.
• Assessment of the role of mouse cancer studies in reference dose setting and cancer classification.

Main Results:

• No significant difference in sensitivity was observed between 3-month and 12-month dog studies.
• Only two compounds required the 12-month dog study NOAEL due to being more than twofold lower than other studies.
• Mouse cancer studies were critical for reference dose setting in 5% of cases and cancer classification in 1.5%.

Conclusions:

• The 12-month dog study and mouse cancer bioassays may be considered redundant in many risk assessments.
• Regulatory agencies should periodically review and update their study requirements to eliminate unnecessary testing.
• Streamlining data requirements can improve the efficiency of toxicological risk assessments.