based on their 2001 proposal and I'll try to remember to indicate, as I go through it, how things have been changed, based on the most recent report and the presentation that you just heard.
So I'm going to look at some of the issues that have been raised regarding the FDA draft guidance and how the IPAC-RS proposal addresses those issues and then my own view as to whether the details of what the IPAC-RS proposes support the claims that they make.
So this is the FDA proposal. You've seen it a couple of times. It's what's called a two-tier or a two-stage testing proposal: first tier, 10 containers with acceptance criteria that I don't need to repeat. It goes to the second tier, an additional 20 containers for 30 total, and then criterion at the second stage. And as has been mentioned a couple of times, we've got a requirement on the mean and a zero tolerance criterion at both stages.
So really there are three pieces, as Dr. Adams had alluded to. We've got an inner interval, which is sort of the formal test by attributes as the quality control language uses it; the outer interval, the zero tolerance criterion, sometimes referred to as the safety