NOVELTY - An electrochemical cell comprises a fuel cell (c1) comprising a housing having an external surface and an internal surface defining an internal volume of the housing; and a fuel consuming agent disposed on the external surface.    USE - For controlling fuel leak (claimed).    ADVANTAGE - In the cell, the fuel consuming reaction occurs without generating significant heat or causing an increase in temperature. Thus, the reaction may not generate sufficient heat to induce ignition of the air-fuel mixture. The fuel cell, cartridge, or container including the fuel consuming agent are safer; require little to no human intervention in the event of a fuel leak because the agent consumes any potentially dangerous fuel as it leaks from the cell, cartridge or container. The fuel consuming coating including the fuel consuming agent converts a potentially harmful, flammable fuel (e.g. hydrogen gas) into relatively harmless, nonflammable byproducts (e.g. water) at ambient temperature. The fuel consuming agent is prepared economically and efficiently, with inexpensive and readily available materials; is durable; and forms a coating that is resistant to peeling, flaking, or crumbling. The fuel cartridge including the fuel consuming agent is portable and safe source of hydrogen gas.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) an electrochemical cell system comprising a fuel cell having a fuel cell housing having a first external and internal surface defining a first internal volume of the fuel cell housing, and cathode, anode and electrolyte disposed within the first internal volume; a fuel cartridge connected to the fuel cell; and a fuel consuming agent disposed on at least one of the first and second external surface. The cartridge comprises a cartridge housing having a second external and internal surface defining a second internal volume of the cartridge housing, where the second internal volume includes a fuel;    (2) an electrochemical cell system (s1) comprising a fuel cell having a fuel cell housing, a fuel cartridge connected to the fuel cell, and a fuel consuming agent disposed on at least one of the fuel cell and cartridge housing. The cartridge comprises a cartridge housing;    (3) a hydrogen gas cartridge comprising a housing including hydrogen gas, and a hydrogen consuming agent disposed on the external surface. The housing has an external surface and an internal surface defining an internal volume. The hydrogen consuming agent is dispersed in a gas-permeable matrix;    (4) a fuel cartridge comprising a housing including a fuel; and a fuel consuming agent disposed on the external surface. The housing has an external surface and an internal surface defining an internal volume. The fuel consuming agent is dispersed in a gas-permeable matrix;    (5) an electrochemical cell system (s2) comprising a container having an internal surface defining an internal volume; and a fuel consuming agent and a fuel cell disposed within the internal volume; and    (6) coating of a fuel cell or cartridge involving coating a portion of an external surface of a fuel cell or cartridge with a fuel consuming agent. In the coating of fuel cartridge, the fuel consuming agent is dispersed in a gas-permeable matrix.