Immediately after removing an alginate impression from the mouth, the FIRST step before disinfection is to:

Rinsing under running water removes saliva, blood, and debris (bioburden) so the disinfectant can work effectively. The impression is then disinfected by spraying or short immersion in an appropriate disinfectant per manufacturer times to avoid dimensional change.Other options: Pouring without disinfection risks cross-contamination; prolonged immersion distorts alginate; bagging debris-laden impressions does not disinfect.Key exam takeaway: Rinse first to remove bioburden, then disinfect (spray or short immersion); do not over-soak alginate.