At the interface between two regions, for example the air–liquid interface of a lipid solution, there can arise non-equilibrium situations. In most cases, the condensed phase is not in equilibrium with the vapor phase, and as a consequence there will be evaporation of water and possible also other volatile components. There might also be dissolution of compounds from the gas phase into the solution. This non-equilibrium situation implies several simultaneous transport processes across the interfacial layer separating the condensed and the gas phases, which in turn can have consequences on the molecular organization in the interfacial layer. In system containing of self-assembling amphiphilic molecules or colloidal suspensions, there is then a possibility of transport-generated interfacial phase separation. This is an apparent possibility in laboratory experimental studies of amphiphilic and colloidal systems. Similar conditions also exist in living system, with obvious examples found in the lipid tear film formed on our eyes, which prevent evaporation and dry eyes, and the membrane system in the alveoli of the lung. In this study, we explore the underlying mechanisms of transport-generated interfacial phase separation using a combination of surface together with theoretical modelling solving diffusion equations.