Pepper spray
While none of us want to use pepper spray, a lot of us will make sure that we have it in our bags when we go out alone. The company Mace says that it’s products have a shelf life of 4 years. They generally will have expiration dates on the packaging.
Why do you want to keep an eye on it? Well, after these dates, the chemicals inside the bottles aren’t as effective, as they won’t be pressurized enough to work properly. Worth bearing in mind if this is one of your purse regulars. So, after the third year, you might want to consider picking up a new can or pepper spray.