ELECTRICIANS WERE INSPECTING A THERMOCOUPLE ON THE LINE 1 ALKALI BAGHOUSE INLET. THEY DESCENDEDA LADDER TO REACH THE THERMOCOUPLE. WHILE WALKING ALONG THE WALKWAY TO THE THERMOCOUPLE, EE WAS EXSPOSED TO A COUPLE OF ""PUFFS"" OF BAD SMELLING HOT GAS. BAGHOUSE AND DUCT IS NORMALLY UNDER A SLIGHT VACUUM. HE FELT NO DISCOMFORT AFTER THE EXPOSURE, BUT REPORTED IT TO HIS SUPERVISOR.