Formation and destruction of propanol as a function of time in the chemical models. Left panels: net rate of change (arbitrary units) in the abundances of normal- and iso-propanol, summed over all chemical phases, during stages 1 and 2. Data correspond to the slow warm-up timescale in stage 2; the vertical dotted line indicates the start of the warm-up phase. Net gain is shown in green, net loss in blue. Vertical dashed lines indicate the onset and end-point of water desorption. Background colors indicate the dust temperature regime; from left to right these are: >10, <10, 10–50, 50–100, 100–200, and 200–400 K. The initial dust temperature is ~14.7 K. Right panels: net rates of change integrated over each temperature range. Positive (formation) and negative (destruction) rates are integrated independently; both are normalized to the total integrated formation rate.