Most common form of disinfection of alginate impression material is: (A) Spraying 1% sodium hypochlorite, (B) Spraying 5% sodium hypochlorite, (C) Immersing in 1% sodium hypochlorite, (D) Immersing in 5% sodium hypochlorite
Answer is A. The  current  protocol  for  disinfecting  hydrocolloid impressions recommended by the Centers for Disease Control and Prevention is to use household bleach (1-to-10 dilution), iodophors, or synthetic phenols as disinfectants. 
Guide for selection of Appropriate Disinfection Method for Impressions Transported to a Dental Laboratory