Filtration Information Network: There are still some out there, which believe in paper instead of testing. Robust proof of filter performance testing, at least firm evaluations, whether sterilizing grade or not, shall prevail over paper. It is stated; by just specifying the use of a sterilizing grade filter, the end-user gets by with a paper-based risk assessment and no validation whatsoever. One specifies a sterilizing grade filter, one has to validate it as such and it does not matter whether the buffer needs to be sterile or not. A performance claim is made, you have to proof it. See PDA TR 26, FDA 2004.