EMPLOYEE WAS CHECKING THE CAUSTIC WASH BY DRAINING THE CAUSTIC THROUGH A SNUB HOSE. THE HOSE IS CONNECTED WITH A DIXON CROW'S FOOT HOSE CONNECTION (QUICK COUPLING) AND ATTACHED TO A TEE IN THE FLOCCULENT LINE. WHEN THE VALVE TO THE HOSE WAS OPENED, CAUSTIC SPRAYED OUT THE CROW'S FOOT GASKET CONTACTING HIM IN THE FACE (PUSHED CAUSTIC UNDER HIS GOGGLES) AND HIS LEFT UPPER ARM.