An oxygen supply system for a station operator includes an oxygen cylinder; a mask operably connected to the oxygen cylinder; a pouch operably connected to the mask; carbon dioxide scrubber disposed inside the pouch; first one-way valve operably connected between the mask and the pouch for allowing one-way flow of gases exhaled by the operator from the mask to the pouch; and second one-way valve operably connected between the mask and the pouch for allowing one-way flow of gases from the pouch to the operator.