Column density of the main ice constituents computed with Nautilus for the static physical conditions as observed in L429-C as a function of visual extinction (derived from Herschel observations). Diamonds represent the observed column densities by Boogert et al. (2011) on specific positions of the cloud. The model result at two different times are shown: 10⁵ yr on the left and 10⁶ yr on the right. The dust temperature is equal to that observed by Herschel.