How to Store Bacteriostatic Water Safely Confused about whether BAC water needs refrigeration after opening? According to USP standards and Pfizer's own guidance, both room temp (2025C) and refrigeration are acceptable Should BAC water be refrigerated or stored at room temperature? How to Store Bacteriostatic Water Safely Confused about whether BAC water needs refrigeration after opening? According to USP standards and Pfizer's own guidance, both room temp (2025C) and refrigeration are acceptable Reconstitution = mixing your peptide powder with bacteriostatic water, Best practice:, Room temp bac water, Inject slowly along vial wall, Avoid foam bubbles, Gently swirl (never shake),