Chemical Dissipation from Outdoor Plastics: The Significant Impact of Transformation Processes Revealed by Adjusted Mass Transfer Modeling.

Summary

In a 180-day outdoor study of three plastic net types, the authors quantified dissipation of 20 priority chemicals, including multiple sunscreen agents and UV stabilizers. Sunscreen and PAH concentrations dropped below 50% within 5 days, and an adjusted mass transfer model that integrates transformation processes accurately reproduced observed kinetics.

Key Findings

• Outdoor dissipation of 20 priority chemicals from three plastic protective nets was quantified over 180 days.
• Sunscreens and PAHs decreased to less than 50% of initial concentrations within 5 days.
• An adjusted mass transfer model that integrates transformation processes reproduced dissipation kinetics with strong determination coefficients.
• Findings enable improved environmental exposure estimates for sunscreen agents and UV stabilizers.

Clinical Implications

Dermatology and cosmetic stakeholders can use these data to prioritize safer UV filters and stabilizers and support labeling and stewardship that minimize environmental release while maintaining photoprotection.

Limitations

• Study focused on three plastic net types and a single outdoor context; generalizability to other products/environments may be limited
• Health endpoints were not directly assessed

Future Directions

Extend to diverse polymers and climates, link dissipation to biotic uptake and human exposure, and develop standardized test protocols for regulatory use.