Abstract: ON THE EVENING OF MARCH 28, 1985, FIVE EMPLOYEES ENTERED ONE OF THE THREE SOLUBLE OIL SECTIONS OF THE DRAINED SOLUBLE OIL LUBRICANT/COOLANT TANK ON THE CONTINUOUS COPPER CASTING-TO-ROD MILLING LINE. EMPLOYEE #1 ENTERED THE SECTION TO CLEAN IT OF COOPER OXIDE PARTICULATE AND LUBRICANT. AFTER A HALF HOUR HE SMELLED ALCOHOL AND LEFT THE SPACE. HE TOLD NO ONE ABOUT THE ALCOHOL SMELL. EMPLOYEE #2 ENTERED THE SECTION. HE WAS RENDERED UNCONSCIOUS WITHIN A FEW MINUTES. EMPLOYEES #3 THROUGH #5 THEN ENTERED THE SECTION TO RESCUE EMPLOYEE #2. THE SOLUBLE OIL CONTAINS WATER, 5% OIL AND 1% ISOPROPYL ALCOHOL. 1,1,1, TRICHLOROETHANE WAS USED TO CLEAN THE LINE'S ROLLER MILL. SOME OF IT HAD DRAINED BACK INTO THE TANK THROUGH GRAVITY DRAIN LINES. WHEN EMPLOYEE #1 PNUEMATICALLY VACUUMED THE TANK'S RESIDUE, THE AGITATION CAUSED THE VAPORIZATION OF THE TRICHLOROETHANE UNDER THE WATER-SOLUBLE OIL. THE THREE EMPLOYEES WHO RESCUED EMPLOYEE #2 POSITIVELY IDENTIFIED THE VAPORS AS TRICHLOROETHANE. NO RESPIRATORS WERE WORN DURING THE CLEANING OR DURING THE RESCUE. THE TANK HAD NOT BEEN VENTILATED BY FORCED AIR METHOD PRIOR TO OR DURING ENTRY. NO TESTING OF THE TANK'S ATMOSPHERE FOR ISOPROPYL ALCOHOL, 1,1,1, THRICHLOROETHANE OR OXYGEN DEFICIENCY WAS DONE. THE EMPLOYEES WERE NOT TRAINED IN RESCUE PROCEDURES OR CPR. NO LIFELINES OR HARNESS WAS USED. THE LUBRICANT DRAIN LINES AND OTHER LINES INTO THIS SECTION WERE NOT BLANKED OR DISCONNECTED. EMPLOYEE SYMPTOMS INCLUDED SEVERE HEADACHE, LOSS OF MEMORY, FAINTNESS AND DIZZINESS. A BULK SAMPLE ANALYSIS SHOWED 0.63% V/V ISOPROPYL ALCOHOL AND 0.29% V/V 1,1,1, TRICHLOROETHANE.