A device for reducing the concentration of a gas from a gas source is described. The device includes a housing having a proximal end, a distal end and a length therebetween that at least partially encloses an interior region, wherein the proximal end has a gas inlet connectable to a gas source, and the distal end has a diluted gas outlet, a nozzle having at least one gas outlet, wherein the nozzle extends within the interior region of the housing, and wherein the nozzle gas outlet is fluidly connected to the housing gas inlet such that gas entering the housing gas inlet exits through the nozzle gas outlet, and at least one opening in the housing length, wherein the opening is adjacent to the at least one nozzle gas outlet and permits air to enter the housing interior region near the nozzle gas outlet. The device is incorporated into a gas delivery assembly, whereby excess gas can be safely purged from the assembly at a diluted concentration via the device.