Some think you need to wait 3 days because they believe BA is busy killing bacteria. I trust ba to the extent of being an antimicrobial (microbes wont multiply) - nothing more. For sterilization, I put my trust in filtration. Whatman guarantees a sterile product after filtration. None of us are 100% sterile with our conversions, but if you are clean, and use common sence everything should be ~sterile after the filter. Case in point, ive shot mere minutes after filtering, and Ive always been fine.