We recently heard from 'BadgerWI', who asked, "I have some water hardness test strips from an earlier purchase from your company. The expiration date on that bottle is fourth-quarter 2014. Can you help me understand-are the strips worthless or are they going to give an accurate reading?"
Thank you for the question. Our current inventory (as of February 7, 2017) for WaterWorks Total Hardness has an expiration date of 5/2018.
About expiration dates
Expiration dates represent the last date that the product's manufacturer guarantees the performance of a product. Does that mean the testing product will absolutely stop working once that date passes? No, but the manufacturer and sellers of the product will not guarantee the accuracy or reliability of test results obtained by using their product after its expiration date.
In your case, Badger, since the water hardness test strips you say you currently possess expired back in 2014, that much time passing since their expiration date would definitely cause us to not trust the results they give.
Determining a product's expiration date
Manufacturers perform careful, controlled experiments using previously calibrated solutions of know concentrations over periods of time to determine how long a testing product will remain 'good' after its manufacture. Once results of testing begin to vary from expected values, the manufacturer notes how much time has passed since the product got made and that time becomes the product's expected shelf-life.
Why would a product begin failing before the end of its shelf-life?
Many reasons exist for why water testing products we carry might fail prematurely, but the big ones are as follows:
- Water test kits stored in direct sunlight
- Water test kits stored in warm or hot temperatures
- Water test kits stored in close proximity to vapor or gas emitting chemicals (i.e. keeping pool test strips next to pool chlorine)
- Water test kits stored in an overly humid environment (Most products have desiccant packs in their bottle/containers to absorb humidity)
- Water test kits stored in improperly sealed containers that allow the entry of outside air and/or moisture (In other words, remember to close your bottle of strips tightly after removing one for use!)
How can I get the current shelf-life of your testing products?
Just ASK and we will gladly tell you!
WaterSafe Well Water Test Kit
WaterSafe Pesticides Test Kit
Lead in Water Test