Safe-by-design principles rely heavily on hazard assessment data of chemicals in commerce. Unfortunately, such information is lacking for a wide range of substances, particularly concerning the persistence and toxicity of industrial chemicals. This project aims to address this knowledge gap by developing high-throughput screening tests to investigate the environmental hazards of synthetic antioxidants.

Synthetic antioxidants are contaminants of emerging concern due to their widespread use in various applications, including as preservatives in plastics, fire retardants, synthetic fibers, fuels, and even foods. As a result, these compounds are now frequently detected in multiple environmental matrices, including natural water bodies, sediments, air, and biota [1]. While previous studies have shown that certain synthetic antioxidants and their transformation products can exert toxic effects on living organisms, data on the environmental fate and (eco-)toxicity of most compounds within this diverse and extensive class remains limited [2].

To address this data gap, we first assessed the environmental persistence of 60 phenolic antioxidants using activated sludge biodegradation assays, alongside the development of a targeted LC-MS analytical method for the detection of a broad range of phenolic antioxidants. Activated sludge biotransformation experiments represent a higher-throughput yet robustly predictive alternative for biodegradation testing in complex environmental microbial communities, thereby enabling more efficient data collection for persistence assessment. To further optimize this approach, we integrated a full sludge suspension extraction procedure into the method, addressing the challenges associated with testing strongly sorbing antioxidants in activated sludge. Building on this, we are developing methods to couple biodegradation assays with animal-free in vitro bioassays to evaluate multiple cellular toxicity endpoints before and after simulated degradation [3].

Our findings will provide critical data for the environmental hazard assessment of phenolic antioxidants. Moreover, the tested workflows and optimized analytical method may eventually be integrated into the early stages of the chemical development process for emerging synthetic antioxidants, thus providing essential information for the design of safe and sustainable chemicals.

[1] Liu, R. & Mabury, S. A. Environ. Sci. Technol., 2020, 54, 11706–11719.

[2] Seller-Brison, C., Weissbach, F., Jorner, K., Scheringer, M. & Fenner, K. Environ. Sci. Technol. Lett., 2026, 13 (4), 560-567.

[3] Escher, B. I. et al. Arch. Toxicol., 2023, 97, 1267–1283.