Acute intravascular hemolysis due to accidental formalin intoxication during hemodialysis.

A patient accidentally exposed to formalin during hemodialysis developed acute intravascular hemolysis. In vitro study showed that formalin has direct oxidant action on red blood cells. Formalin intoxication should be recognized as a cause of acute hemolysis during hemodialysis and is not invariably fatal, provided further exposure is stopped in time and the complications prevented.