Depending on what type of foam concentrate you have, the typical shelf life will vary.Protein type concentrates have a shelf life of about 7 to 10 years.
The synthetic type concentrates, which are the AFFF, ARC type AFFF, Class “A” and High-Expansion concentrates, have a shelf lives of 20 to 25 years.
Click Here to download the Ansul Technical Bulletin on AFFF Shelf Life