
Proper Storage Conditions for DuPont Ion Exchange Resins
If kept in their original packaging and stored properly, most unused ion exchange resins can last well beyond their recommended shelf life without losing their physical quality. Regular demineralizing and softening resins usually hold up well for at least five years. For more delicate uses, shorter storage times might be suggested, and any exceptions will be listed in the product’s data sheet.
General Guidelines:

Storage of New, Unused Resin:
The manufacturing and re-test dates are listed on the Certificates of Analysis and usually printed on the packaging labels. It’s a good idea to check the resin’s condition after the recommended shelf life to make sure it still meets standard specs.
For best results, keep resins in their original, unopened packaging and store them in a cool, dry place. An indoor area with climate control between 36–105°F (2–40°C) is ideal.
If temperatures go above 105°F (40°C), anion resins—especially in the OH-form—can lose performance early. Cation resins can handle more heat (up to 175°F or 80°C), but it’s still safest to store all types at the same moderate conditions.
If resins freeze (below 32°F or 0°C), it can cause damage. DuPont testing shows repeated freeze-thaw cycles can harm the resin beads. If resin does freeze, let it thaw completely at room temperature before using or loading it.
Storage of Used Resin:
Just like new resins, used resins should be stored in climate-controlled conditions when possible to help extend their life.
Also, try to keep them sealed and away from air—if they dry out, the beads can shrink. When you rehydrate dried-out resin, the beads can crack from swelling too fast. To avoid this, soak them first in a strong salt (NaCl) solution. The salt helps control the swelling. You can then gradually rinse out the salt to safely bring the resin back to normal.
If resin sits unused for a long time, biological growth (biofouling) can become a problem. To prevent this, store the resin in a strong saltwater (brine) solution. It not only helps stop microbial growth but also keeps the resin from freezing.
Here’s what we recommend for storing used resins used in water demineralization:
- After the resin is exhausted and backwashed, it’s ready for storage.
- Fill the vessel with a 15–25% salt solution, making sure no air is left inside.
- When it’s time to use the resin again, gradually rinse it with weaker salt solutions to avoid shock from sudden swelling.
- Before putting it back into service, give it a double or triple regeneration.
For mixed bed resins used in condensate polishing or ultrapure water systems:
- Separate the resins and regenerate them twice.
- Rinse out any leftover regenerants and leave the resins sitting in rinse water.
- Once a week, flush the resins from the top down to clear out any TOC (Total Organic Carbon) buildup.
Before restarting, rinse and regenerate the beds as usual. If you have more questions about resin, or purchase resin, please feel free to reach out to our knowledgable team at Detroit Sponge.

