Pepper spray does in fact have a shelf life. The average shelf life of a pepper spray is typically around 3 to 4 years. Most defense sprays have an expiration date stamped on the canister. A pepper spray’s effectiveness is derived mainly from its chemical compound of OC or Oleoresin Capsicum. OC is a natural chemical comprised of various hot pepper plants, hence the name Pepper Spray. Although the OC will not degrade over time, an expired canister may not spray as far as expected and in some cases the unit may fail to spray entirely. A spray that is kept beyond its shelf life has a potential for the aerosol propellant to leak out and render the spray less effective. Leakage is especially common in smaller type sprays such as key chain and pocket versions.
Since the chemical potency of pepper spray is vital in their effectiveness, it is strongly recommended to replace a spray well before its expiration date. It is also advisable to test your canister of spray periodically and at least once every 6 months. A simple test would only require a one second burst to be sprayed outdoors and standing upwind to prevent self contamination. A regular inspection of a spray’s expiration date and overall condition will always ensure a potent and reliable protection device to be readily available when needed. When the time for replacement is established, the old canister of OC spray makes a great training and practice tool. It is always a good idea to set up a target outdoors and practice spraying the old spray to test aim and gain confidence when using a defense spray in a real life situation.