Check If Your Paintball Co2 Tanks Is Still In Date

If you are a paintball enthusiast, you should be aware of properly fill and maintain the CO2 tanks used for this purpose. For your own safety and that of others around you, it is important to make sure that your paintball CO2 tanks are within date. Out-of-date tanks require hydro testing to ensure that moisture and other possible defects have not compromised the integrity of the tank. Failure to have the tank re-tested after the expiration date could result in serious injury if the tank ruptures or malfunctions.


1. Remove the tank from the paintball gun. Locate the Department of Transportation (D.O.T.) Exception Regulation number on the cylinder’s label. This identification starts with an “E,” followed by a five-digit number. Use this number on the manufacturer’s website to locate the time period before the tank requires re-testing (usually between three to five years).

2. Locate the hydro test date on the tank’s label. Some labels will show “Rehydrotest By.” If the date falls outside the current date, the tank will require re-testing before it is put back into use. Other labels may have the date when the tank was last tested. Add three or five years to the date shown on the label, according to the time period represented by the “E-number” found on the tank.

3. Locate any other markings on the tank. Some tanks may have “3AL” or “3HT” stamped on the tank, depending on the tank’s composition (aluminum, steel or fiber-wrapped). Tanks that have “3AL” stamped must be tested every 5 years. Tanks marked “3HT” must be tested every 3 years and have a lifespan of 24 years.