Expiration

Old Spray (3+ Months)

Reasonable Expectations

When the sprayer bottle is properly protected from light, and kept in a cool place, the mixed STS can remain viable for months. 

New Batch Every Business Day

We at silverthiosulfate.ca make a new batch every day we ship.  We NEVER use old materials, and we always print a mixed on date on every bottle.

Simple Visual Inspection

You can check to see if the solution is still viable by pouring a bit out in a clear glass. The solution should be crystal clear.