Mode of action approach supports a lack of carcinogenic potential of six organic UV filters.

Summary

The authors propose and apply a mode-of-action framework to evaluate carcinogenic potential of six commonly used organic UV filters (avobenzone, ensulizole, homosalate, octinoxate, octisalate, octocrylene). Synthesizing mechanistic, exposure, and toxicology data, they argue rodent 2-year bioassays are often not human-predictive and conclude current evidence supports a lack of carcinogenic potential for these filters.

Key Findings

• Proposes a mode-of-action (MOA) framework integrating exposure and mechanistic data to assess carcinogenic potential.
• For six organic UV filters (avobenzone, ensulizole, homosalate, octinoxate, octisalate, octocrylene), current evidence supports lack of carcinogenic potential in humans.
• Highlights poor human predictivity of traditional 2-year rodent carcinogenicity studies and offers an alternative supplemental approach aligned with FDA safety concerns over systemic absorption.

Clinical Implications

Reinforces that sunscreens containing these filters can remain recommended for skin cancer prevention while additional data are considered. Encourages adoption of human-relevant MOA frameworks, potentially reducing unnecessary long-term animal studies.

Limitations

• Narrative framework without new experimental carcinogenicity data.
• Conclusions depend on completeness and quality of existing toxicology datasets.

Future Directions

Prospective validation of the MOA framework with human-relevant in vitro/new approach methodologies and regulatory case studies; harmonization with international guidelines to replace or reduce 2-year rodent bioassays.