So, I know that bear sprays like Counter Assault have expiration dates on them. I've been told that the issue regarding their "expiration" is not related to the capsaicin losing it's potency, but rather that the propellant slowly leaks out of the canister, and thus the pepper spray doesn't spray as far.
I knew a very experienced Montana hiker who weighed his bear spray every year and wrote the weight on the bottom of the canister so that he could track propellant leak. If the canister got too light, he ditched it and bought a new one, whether or not the expiration date had passed. I started doing this a few years ago too, just to see what the results would be.
My question is this: how much propellant loss is too much?
On the two canisters I have tracked weight on, I found that they seemed to lose the most the first year, and then lost weight much more slowly after that. For example, I have one canister that lost half an ounce the first year, and then another 0.1 oz each of the following three years. (It's past its expiration date now). I have another canister that lost 0.9 oz the first year...but is still 3 years away from it's official expiration date. Should I be concerned that it has lost too much to still be effective? How much loss is too much?
I'm especially hoping that Dave Parker will weigh in on this...hopefully before I mail my box out to MT this week!
Thanks!