Abstract: ON FEBRUARY 21, 1985, EMPLOYEE #1 WAS WORKING ALONE LATE AT NIGHT TUNING A FORD DELIVERY VAN. AT 4 AM, THE EMPLOYEE WAS FOUND DEAD FROM A HEART ATTACK. THE NEXT DAY, EMPLOYEES #2 AND #3 WERE USING A FORKLIFT TO LOAD A DELIVERY VAN WITH 55 GALLON DRUMS. THE EMPLOYEES WERE ALSO PLACING LABELS ONTO PLASTIC BOTTLES, WORKING CLOSE TO AN OVERHEAD HEATER. EMPLOYEES #2 AND #3 WERE TO WORK FROM 8 AM TO NOON. AT APPROXIMATELY 6 PM, THE TWO EMPLOYEES WERE FOUND DEAD. THE CARBOXYHEMOGLOBIN LEVEL OF EMPLOYEE #2 WAS 63 PERCENT AND OF EMPLOYEE #3 WAS 64 PERCENT. FROM A BLOOD SAMPLE, IT WAS DETERMINED THAT THE CARBOXYHEMOGLOBIN LEVEL IN EMPLOYEE #1 WAS 56%. IT WAS FELT THAT THE HIGH LEVEL OF CARBOXYHEMOGLOBIN PROBABLY INDUCED HIS HEART ATTACK. THE ESTABLISHMENT IS ENGAGED IN THE BOTTLING AND DISTRIBUTION OF MOTOR OIL AND IS LOCATED IN A PRECAST, UNVENTILATED BUILDING, 10,000 SQUARE FEET IN AREA AND 150,000 CUBIC FEET IN VOLUME. THE SOURCES OF CARBON MONOXIDE INCLUDED A FORK LIFT TRUCK, A DEFECTIVE OVERHEAD 200,000 BTU HEATER, ANOTHER OVERHEAD 200,000 BTU HEATER (1 YEAR OLD), AN UNVENTED 420,000 BTU HEATER FOR BLENDING OIL, AND SEVERAL VEHICLES WHICH WERE PERIODICALLY BROUGHT INTO THE BUILDING. CARBON MONOXIDE READINGS WERE TAKEN ON FEBRUARY 25, 1985 TO DETERMINE THE LEVELS OF CARBON MONOXIDE EMITTED FROM THE VARIOUS SOURCES. UNDER LOAD CONDITIONS FOR THE FORKLIFT, THE READING WAS 90 PPM. THE FREQUENCY OF FORK LIFT USE IS AS NEEDED, RANGING FROM 5 MINUTES UP TO ONE HOUR PER USE. THE OIL BLEND WATER HEATER READING WAS 150 PPM. THE DIRECTION OF GAS FLOW WAS INFLUENCED BY THE OVERHEAD HEATER. THE FREQUENCY OF USE FOR THE WATER HEATER IS 2 HOURS PER DAY, TWICE A WEEK. IT WAS LAST USED ON FEBRUARY 20, 1985. THE OVERHEAD HEATER WAS MEASURED AT 40 PPM TO 150 PPM. HOWEVER, THE HEATER MALFUNCTIONED DURING THE TEST PERIOD AND STARTED EMITTING COLD AIR. IT IS BELIEVED THAT THE HEATER MAY HAVE BEEN THE PRIMARY CAUSE OF THE CARBON MONOXIDE PRESENCE. THERE WAS NO MONITORING OR MAINTENANCE PROGRAM FOR THE EQUIPMENT. THE WEATHER CONDITIONS MAY HAVE PLAYED A ROLE AS THERE WAS A DENSE FOG AND A TEMPERATURE INVERSION FOR APPROXIMATELY A 40 HOUR PERIOD, DURING WHICH THE EMPLOYEES WERE KILLED.