Do O+ products ever expire?

Each O+ oxygen product states “Best by 24 months from fill date” on the canister. The fill date is located on the bottom of each canister. While the gas of oxygen itself never expires, we added this "shelf life" or product lifespan timeframe to ensure you're completely satisfied with the value of your purchase well beyond the typical time you'd finish a canister. After 24 months, O+ products will still work and are safe to use if stored as directed, however a user may experience slightly fewer “breaths.” FYI, a canister that's been opened or used does not expire any faster than an unopened canister.

To provide more detail, while the oxygen content inside the canister does not degrade over time, there is a possibility that a slight loss of pressure in the canister may occur after a 24 month period due to atmospheric pressure and temperature changes. That is why it is important that the product is stored properly in a cool, dry place and does not exceed 49° C/ 120° F.  Oxygen Plus stability testing has shown the contents of O+ products (pure recreational oxygen) retain integrity well after the 24 month period.