State of the art in fermentation air filtration

This article presents several characteristics of a state-of-the-art fermentation air filter. The filter medium is composed solely of PTFE and has an absolute pore size rating of 0.2 mum. Quantitative bacteria and bacteriophage retention is shown based on live organism challenge tests. A nondestructive filter test, correlated to the microorganism challenge tests and called the Forward Flow Integrity Test, is described. This test has a sensitivity of one part in 10(12) and can be performed in situ.