The PES and glass beaker extracts were diluted with ACN/internal standard before subjected to LC-MS/MS analysis (Section S6, SI). The acute ecotoxicity test with D. magna was performed following OECD Test Guideline 202. Neonates less than 24 h old were exposed to a single BAC homolog at five concentrations and a control (with or without methanol), with 5 newborns in each of four replicate beakers. Test solutions were prepared by dissolving pure solid in water (C6-BAC), by diluting methanol stock solutions with water in a 300 mL flask before transferring to test beakers (C8-, C10-BACs), or by directly adding methanol stocks to water in test beakers (C12-C18-BACs), considering that longer chain BACs are more susceptible to losses during solution preparation. For all BACs except C6, the final methanol concentration in water was 0.01% (v/v).