Abstract: EMPLOYEE #1 WAS WASHING THE INTERIOR OF A TRUCK TANK WHICH HAD PREVIOUSLY CONTAINED PERCHLOROETHYLENE. ANOTHER EMPLOYEE, ASSIGNED TO OBSERVE EMPLOYEE #1, LEFT THE AREA MOMENTARILY. EMPLOYEE #1, WHO WAS USING A PRESSURIZED HOT WATER LINE TO CLEAN THE TANK, WAS UNCONSCIOUS WHEN THE OBSERVER RETURNED. OTHER EMPLOYEES QUICKLY REMOVED EMPLOYEE #1 FROM THE TANK (THEY DID NOT CHECK THE TANK'S ATMOSPHERE OR USE ANY KIND OF RESPIRATORY PROTECTION OR LIFELINES). EMPLOYEE #1 REGAINED CONSCIOUSNESS QUICKLY, BUT SUFFERED FIRST AND SECOND DEGREE BURNS FROM THE HOT WATER WHICH HAD SPILLED ON HIM. HE WAS TRANSPORTED TO THE HOSPITAL AND RELEASED THAT AFTERNOON. THE EMPLOYEES HAD NOT BEEN PROPERLY TRAINED ON THE CORRECT PROCEDURES FOR ENTERING CONFINED SPACES.