LINE 1 SCRUBBER TOWER WAS PROPERLY ISOLATED FROM PROCESS GAS (KILN EXHAUST GAS) IN PREPARATION FOR OPENING THE MANDOORS TO VISUALLY INSPECT THE DEMISTING PADS FROM THE OUTSIDE OF THE VESSEL. THERE WAS QUITE A BIT OF STEAM COMING FROM THE MANDOOR. THE UPPER DAMPER WAS OPENED IN A EFFORT TO CREATE A DRAFT AT THE DOOR AND CLEAR THE STEAM, SUFFERED ASTHMA ATTACK.