ChlorineTPS , all reported as suitable for negative ESI. The mass accuracy threshold for suspect shortlisting was set to 5 ppm. All library matches were reviewed manually to assess alignment, peak shape, isotopic composition (M, M+1, M+2) and possible alternative structures in Pubchem for the same elemental composition. For candidate peaks with intense signals, DIA deconvolution was investigated for diagnostic MS/MS fragments. For the remaining candidates, a dedicated product ion scan was performed during additional chromatographic runs (details in Table ). Tentatively identified substances were confirmed where a standard was commercially available. Toxicity data for substances identified with confidence level 1, 2a and 2b were either found in literature or predicted with the US EPA Toxicity Estimation Software Tool (TEST). The endpoint considered for predicted toxicity were oral rat LD50, developmental toxicity and mutagenicity with nearest neighbour method.