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 is primarily derived from its chemical compound of OC or Oleoresin Capsicum. OC is a naturally occurring chemical made from various hot pepper plants, hence the name Pepper Spray. Although the 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 useful life has the potential for the propellant in the aerosol to leak and make the aerosol less effective. Leaks are especially common in the smaller type aerosols, such as the key fobs and pocket versions.
Since the chemical strength of pepper spray is vital to its effectiveness, it is strongly recommended to replace a spray well before its expiration date. It is also advisable 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 prevent self contamination. 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 the time for replacement is set, 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 sprinkler to test your aim and gain confidence using a defense sprayer in a real life situation.