During the midyear, there was a presentation on alarms in infusion pumps. Someone asked what is considered a safe amount of air. 7 Years ago, I took a pump through FDA clearance, and this very question was posed. I didn't have time to write and send the letter to the editor fast enough...Anyway, if interested, below is the possible rationale based on clinical evidence, which might explain why the regulatory bodies continue to have a conservative approach.