Concentrate is 4 years and sealed dilution is about 8 months.
Spot cleaning tubs daily and full cleaning every 6 to 8 weeks one spray bottle would last me about 6 or 7 months. (Wash tubs with soap and water, dry and then wipe with F10)
I can get about 20 spray bottles out of a 6.8 ounce bottle of F10 SC, not even half way through half a bottle by time the expiration date on the bottle comes around.
I just looked and found the one I thought I threw out when I cleaned out the top of the racks....... Expired March 2013 and its still 3/4 full.
You have to remember the 4 years starts from when they bottle it.
Plus we use green soap for other cleaning around the house so we go through it faster and I can get it local.
http://www.f10products.co.uk/ebooks/...ublication.pdf