Relative abundances of the main isotopologues with respect to CH₃OH, towards IRAS 16293 A in red and IRAS 16293 B in blue. The abundances towards IRAS 16293 B are based on Persson et al. (2018) for H₂ CO, Lykke et al. (2017) for CH₃CHO, c-H₂ COCH₂, and CH₃ COCH₃, Jørgensen et al. (2016) for CH₂(OH)CHO and CH₃ COOH, and Jørgensen et al. (2018) for CH₂CO, CH₃ OCH₃, C₂ H₅OH, CH₃ OCHO, (CH₂ OH)₂, and t-HCOOH. We note that 30 and 10% of the uncertainties on the column density are considered for IRAS 16293 A and IRAS 16293 B, respectively.