This is another part of my recent respirator articles; my attempt to help up-and-coming program administrators understand what OSHA is actually requiring as the absolute minimums. This post is about the “numbers” we see and hear when discussing respiratory protection. As I posted a few months ago, during an audit for a client, we came across emergency responders who had been fit-tested using Quantitative Fit Testing (QNFT) for an SCBA and “passed” with a Fit Factor well below 500. This was a serious error, but how many actually understand where the Fit Factor of 500 for a Full Face Respirator comes from? Well, here is what OSHA has to say about the Assigned Protection Factors, Fit Factors, and the “Safety Factor” when developing, implementing, and managing a respiratory protection program….