Pepper spray does, in fact, have a shelf life. The average lifespan of a pepper spray is usually around 3-4 years. Most defense sprays have an expiration date stamped on the container. The effectiveness of a pepper spray stems primarily from its chemical compound of OC or Oleoresin Capsicum. OC is a natural chemical made up of various hot pepper plants, hence the name Pepper Spray. Although OC will not degrade over time, an expired container may not spray as much as expected and in some cases the unit may not spray at all. An aerosol that is kept beyond its shelf life has the potential for the propellant in the aerosol to leak and make the aerosol less effective. Leaks are especially common in smaller type sprays, such as the keychain and pocket versions.
Since the chemical strength of pepper spray is vital to its effectiveness, it is strongly recommended that you replace a spray well before its expiration date. It is also recommended to test your spray can periodically and at least once every 6 months. A simple test would only require a one-second burst to spray outdoors and standing upwind to avoid self-contamination. A regular inspection of the expiration date and general condition of a spray will always ensure that a powerful and reliable protection device is available when needed. When it’s time for replacement, the old OC spray can is a great training and practice tool. It’s always a good idea to set up a target outdoors and practice spraying the old sprayer to test your aim and gain confidence using a defensive sprayer in a real life situation.