NOVELTY - A fuel cell system (1) includes at least one apparatus (10) having a gas-permeable, in particular porous or honeycomb structure, which contains a substance which reacts with gaseous chromium species, or which is provided with such a substance, and where the apparatus is in communication with at least one of the outlet (4a, 4b) to direct exhaust gases (7a, 7b) through the apparatus and to separate chromium species which are carried along by the exhaust gases.    USE - As fuel cell system (claimed).    ADVANTAGE - The fuel cell system has the advantage that the chromium separated from the exhaust gas is present in bound form in a solid substance which can be disposed of safely. The fuel cell system has the advantage that the chromium content in the condensate can be lowered by more than 50% with respect to conventional fuel cell systems. It furthermore appears possible on the basis of extrapolations to reach a service life of 40000 hours with the apparatus so that no additional servicing is required for the apparatus.    DETAILED DESCRIPTION - A fuel cell system (1) having a cell stack (2) for the carrying out of electrochemical reactions which is provided with inlets (3a, 3b) for an oxidant (5) and/or a carrier gas and for fuel gas (6) and/or water vapor and with outlets (4a, 4b) for exhaust gases (7a, 7b), includes at least one apparatus (10) having a gas-permeable, in particular porous or honeycomb structure, which contains a substance which reacts with gaseous chromium species, or which is provided with such a substance, and where the apparatus is in communication with at least one of the outlet to direct exhaust gases through the apparatus and to separate chromium species which are carried along by the exhaust gases. INDEPENDENT CLAIMS are included for the following:    (1) an apparatus for fuel cell systems including a gas-permeable, in particular porous or honeycomb structure, which contains a substance which reacts with gaseous chromium species, or which is provided with such a substance, and where the apparatus can be coupled to at least one of the outlets of the cell stack or to an afterburner of the fuel cell system to direct exhaust gases through the apparatus and to separate chromium species which are carried along by the exhaust gases; and    (2) a method for using the fuel cell systems, where an electrochemical reaction is carried out in the cell stack and exhaust gas is generated involving directing exhaust gas from the cell stack through the apparatus; and separating chromium species in the apparatus which are carried along by the exhaust gases.    DESCRIPTION OF DRAWING(S) - The figure shows a fuel cell system.    Fuel cell system (1)    Inlets (3a, 3b)    Outlets (4a, 4b)    Oxidant (5)    Fuel gas (6)    Exhaust gases (7, 7a, 7b)    Apparatus (10)