Bacteriostatic Water for Injection: Package Insert Prescribing Info Using BAC water ensures that the pep solution remains stable and pure, preventing the loss of valuable, sensitive compounds. We include 1 free with each order. Check our link in bio. # Should BAC water be refrigerated or stored at room temperature? Your eyes are your first line of defense. Good BAC Water: Crystal clear, odorless (faint alcohol scent), and painless. Bad BAC Water: Cloudy, particulate matter, strong chemical smell, or severe burning.