Five Star IO Sanitizer

[Beer-lord]

A friend gave me a likely 2-3 year old, only 1/3 empty bottle (large) of the IO Star Sanitizer. It looks, smells and feels ok but I wonder, how long these things last. I've found the tech sheet online but it says nothing about how long it last. The label has a 'storage and disposal' section but again, nothing about how long it lasts.
Anyone have an idea?

 

[pvault98]

Do you have a ph meter or strips? make-up a small batch and test the ph, if under 3 then you are good to go.

 

[Beer-lord]

Thanks!