A method, an installation and a nozzle (1) for suppressing the generation of iron-containing vapor during filling or emptying of a container (2) for an iron-containing metal melt with the aid of CO2 snow, a CO2 snow jet (22) being applied by means of the nozzle (1) dispersing in a substantially planar manner onto a surface of an iron-containing stream (23) which is poured into or out of the container (2). The invention consequently at least partially solves the technical problems outlined in connection with the prior art. In particular, a device is proposed which allows cost-effective and space-saving suppression of the generation of iron-containing vapor during the filling or emptying of a container 2 with the aid of a reduced CO2 snow quantity.