Bear Spray Expiration Dates and Propellant Loss

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joybird
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Bear Spray Expiration Dates and Propellant Loss

Post by joybird »

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!
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Re: Bear Spray Expiration Dates and Propellant Loss

Post by daveparker »

If they have not hit expiration date yet, they should be good, I would carry them, Especially if the CA, I always have old cans hanging around some are up to 10 years old and I take them out and test them every once in a while and they are all still good and I would not hesitate to use them. Normally I would start being concerned if you have lost over 30% of the new weight, that would tell me you might have a can that is leaking excessively, but from what you have said in your message, you really have not lost that much on those cans.

Where did you buy them? Locally or at home? and how many times have they been shipped back and forth? Sometimes I have seen cans loose a bit of pressure due to the rigors of shipping.

Anyway, let me know if have any more questions and I will keep checking back.

Dave
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Re: Bear Spray Expiration Dates and Propellant Loss

Post by joybird »

Thanks, Dave. This is exactly the kind of info I was hoping for. 8)

As for your questions, I always buy CA, and always in Montana. The way I treat the canisters has depended on my trip logistics from year to year. Some years I left my canister with a friend out there. Years that I've driven to Montana, I've taken them with me. Occasionally I've used UPS or USPS (ground, of course)...which is what I have to do this year. (Much cheaper than buying two new ones!)

The more recent canister has only been driven back and forth. The older one has been shipped once, or possibly twice.

Based on your feedback I will bring my little scale and re-weigh them when I get out there to make sure the shipping doesn't change things. I hadn't thought of that...

Thanks again! Nice to be able to reassure my Glacier-virgin partner that I'm not just gonna use him as bear bait. :wink: :lol:
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Re: Bear Spray Expiration Dates and Propellant Loss

Post by daveparker »

Glad to be able to help, again if questions come up, please don't hesitate to let me know and have a fantastic trip!
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Re: Bear Spray Expiration Dates and Propellant Loss

Post by PeteE »

Hi Joybird, Dave :)

I made this little video tonight after seeing this thread.
I believe Joybird may have a poor scale.
I know mine are accurate to < .5% 8)



pete :wink:
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And when you're born in America, you're given a front row seat."

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Re: Bear Spray Expiration Dates and Propellant Loss

Post by daveparker »

I recommend, that everybody weigh the canisters when you first purchase them and note on the can what it weighed, that way before each season, you can check it without spraying it.

When I worked at Counter Assault, that is the same way we did it, when filling the cans, for each basket of cans we filled, we had a baseline to make sure our equipment was dialed in correctly and everybody was getting exactly what they needed per the recommendations.
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Re: Bear Spray Expiration Dates and Propellant Loss

Post by July Guy »

Very useful thread, thanks everyone.
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