EMPLOYEE WAS REMOVING NITRIC ACID FROM PARTING CRUCIBLES WITH A TUBE AND SUCTION PUMP. SHE NOTICED THAT THE SUCTION HAD QUIT AND FOUND THE TUBING CAME APART. ACID SPILLED FROM THE DISCONNECTED TUBING ONTO HER LEFT KNEE. SHE CONTINUED WORKING FOR AN EXTENDED PERIOD BEFORE RINSING HER KNEE. THIS DELAY NECESSITATED SKIN GRAFTS.