Do Unused Water Filters Expire? (With Watch Outs & Proper Storage Tips)

When buying stuff, you gotta factor in the shelf-life because that will help you know if you are getting good value. The same can be said of water filters – knowing how long they last will help you know if you are getting a bang for your buck.

You are probably aware that water filters eventually wear out as they are used but what of the unused ones?

Water filters have a very long shelf-life, so they will not expire. As long as you keep the filters away from humid air and UV rays from the sun, you can store them for years. However, if the filter becomes wet, bacteria will form on it and it might not be good to use anymore. Always keep water filters sealed in their packaging until when you want to install them.

There’s almost no need to worry about your unused water filters because they seldom expire. Although cooler temperatures seem to slow down their aging—it’s still safe to stock them up more for future replacement if that’s what makes you worry.

Poorly stored filters are exposed to dangers like;

  1. Contamination – If your unused filters are lying around your home, they may get contaminated. Contamination renders the filters useless or even unsafe for filtering. You might end up adding contaminants to your water rather than getting rid of them.
  2. Damage – Water filters are prone to damage when not stored properly. Delicate parts like filter membranes or cartridges cannot function properly once damaged. A torn membrane will likely let contaminants pass when the filter is installed.
  3. Microbial growth – Bacteria are likely to grow if your unused water filter is exposed to air, warmth, and moisture. This may contaminate your water and result in a bad taste or odor when you use the filter.

Factors affecting the shelf life of your unused filters

The shelf life of your unused filters comes down to how you store them. The moisture content of your storage room will greatly affect the shelf life of your filters. It would not be wise to keep your unused water filters near water sources.

Make sure that your storage room is dry and well-ventilated. Direct sunlight will damage your filters. There is also a misconception that you can safely store unwrapped water filters in the refrigerator. But this is not true because some bacteria can withstand low temperatures.

If the wrapping is broken, immediately use the filter or discard it.

How to tell if your water filter has expired

As we have already established,  you do not have to worry about your unused water filter expiring as long as you store it well. But that is too simplistic because everything has an expiry date and even unused water filters will eventually be unusable at some point.  

So, how do you tell if your unused water filter has expired?

Just check the inside of your water filter. An unused filter should have a white filter membrane. If the filter membrane has coloration, you should dispose of it immediately. In the case of activated carbon cartridges, it is hard to tell since they always come in black. The other trick is to check for the dryness of the filter membrane. If it is damp, the filter is no good.  

If you aren’t sure how long your water filter can last, check with the manufacturer or check the usage instructions to see if it comes with an expiry date.

You can also conduct a test if you are not sure whether your filter is safe for use. Install the filter and look out for the following signs in your water:

  • Strange smell
  • Bad taste
  • Sediments in water
  • Strange sounds in the case of reverse osmosis systems

The dangers of using expired water filters

Water filters should be replaced every 3-6 months or as prescribed by the manufacturer.

Here are some important dangers of using expired water filters:

  • You could be exposing yourself to bacteria inside your filters. If your water filter is expired, there could be bacteria growing in the filter membranes and other parts. Continued use of such water may lead to health complications.
  • Your water supplier might be doing their best to ensure you get safe drinking water. An expired water filter can introduce new contaminants to already clean water. It may also be adding insult to injury by adding contaminants to hard water.
  • Expired water filters are likely to make your water taste and smell bad. In the case of ion exchange filters, your water may end up smelling like rotten fish flesh.

For a more comprehensive explanation, refer to my article on the dangers of drinking water from an old filter

How long do water filters really last?

Unused filters can sit pretty until you are ready to use them if well kept. If you keep them away from moisture and excess heat, you can store them for as long as you want.

Once you open a filter and water passes through it, it is advisable to keep using it until it is time to replace it.

Water filters typically have a service span of six to twelve months after first use. However, other factors can affect the life span of your filter like the amount of water you filter in a day and the condition of your water. Poor quality water will reduce the service span of your water filters.

If you are planning to go away for a while, it is advisable to replace your filters to avoid the risks associated with expired filters.

Do refrigerator water filters expire?

Refrigerator water filters have a life span of three to six months after first use depending on the manufacturer. If you have not used your filter make sure to store it well. Some manufacturers will indicate how long a filter can remain in good condition if not used.

It is best not to use a refrigerator filter if it has not been used for more than a year.

Final thoughts

So, to sum it up, unused water filters will not expire as long as they are stored correctly. Moisture is the greatest enemy of unused water filters, so you will want to keep them in a dry area. Also, be careful not to interfere with the wrapper until when you are ready to use the filter. Just to be safe, you may want to avoid buying in bulk. Just buy enough to last you a year, depending on your unique needs.