Shelf life is 2 years but if bag is properly sealed, they should be good for a minimum of 5 years.
Strips will degrade if exposed to sunlight and come in a dark bag to prevent this. Do NOT transfer to a clear bag or strips will degrade quickly.
Good product that was easy to read. I bought this for a residential water test for high iron. Most water test kits only go up to 5 ppm. I knew mine was higher than that, so needed another product.
Only suggestion is that Indigo could look at selling these in smaller batches for consumer uses. Otherwise, great product.