EE PERFORMING DEMOLITION DUTIES TO DISMANTLE AN IDLE PLANT, WHICH WAS PRESENTED TO USE AS THOUGROUGHLY FLUSHED AND DRAINED, NUMEROUS TIMES, WERE SPRAYED WITH CONCENTRATED CAUSTIC SODA SOLUTION WHEN THEY BROKE INTO A LINE THAT HAD NEVER BEEN FLUSHED. EE RECEIVED CHEMICAL BURNS TO FACE, NECK AND TORSO AS A RESULT OF INCIDENT. PLANT NOW CONFIRMS SOME LINES WERE NOT FLUSHED.