Abstract: EMPLOYEE #1 IS AN EMPLOYEE OF A CHEMICAL WHOLESALE DISTRIBUTION COMPANY. HE WAS DELIVERING APPROXIMATELY 1,000 GALLONS OF SHELL SOL 340 (MINERAL SPIRITS) TO A CHEMICAL MANUFACTURING COMPANY. HE CONNECTED THE HOSE FROM HIS TRUCK TO THE INLET VALVE OF THE 1,000 GALLON STORAGE TANK AND BEGAN PUMPING THE SOLVENT INTO THE TANK. AFTER A FEW MINUTES THE HOSE SUDDENLY RUPTURED AND THE END OF THE CYLINDRICAL, HORZONTAL STEEL STORAGE TANK BLEW OUT. THE EMPLOYEE'S BACK WAS TURNED WHEN THE RUPTURE OCCURRED. HE WAS SOAKED WITH THE LIQUID. NO FIRE OCCURRED. THE STORAGE TANK'S RELIEF VALVE WAS AN OPW 95-UT 2 INCH PRESSURE-VACUUM RELIEF VALVE. THE VALVE WAS ABOUT 20 YEARS OLD. THE TANK WAS APPROXIMATELY 25 YEARS OLD. IT APPEARS THAT THE RELIEF VALVE OPENED ONLY PARTIALLY. 500 TO 600 GALLONS OF SOLVENT WERE PUMPED INTO THE TANK BEFORE THE EXCESSIVE PRESSURE CAUSED THE BLOW OUT. EMPLOYEE #1 RECEIVED FIRST DEGREE BURNS ON HIS BACK.