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 How Much Bacteriostatic Water to Add to Peptides? Prime Peptides Bottled water often carries an expiration or best by date, but pure water itself does not expire or spoil, as it lacks nutrients for bacteria growth. The date primarily concerns the plastic bottle: How Much Bacteriostatic Water to Add to Peptides? Prime Peptides