Thanks for your quick answer :) a lot of bear sprays have physical safety mechanisms to prevent accidental discharges though. But I hear your point.

If the container has a sturdy safety latch, I'd be ok flying with it. Just be careful how you pack it, maybe slip in inside a tube of sorts (pringles jar?) to prevent any mechanical pressure on the operating levers.

The risks from the container bursting or other accidental discharge in a GA plane are pretty much the same as when driving a car, or FTM hiking in steep terrain, riding a horse, &c.

@jamesqf sure, but the consequences are likely to be much more serious

@jamesqf in a car you can pull over (if you are quick enough), but imagine the cockpit of a cessna suddenly filling up with pepper spray... you really can't compare discharging a canister of pepper spray inside a small aircraft to the same event happening outdoors!

@Jpe61: And remember that bear spray is much more potent than spray intended for use against human attackers.

@jamesqf: "...or FTM hiking in steep terrain" Female-to-male hiking?

@Vikki: I wish (sigh). But no, in case you didn't already know, FTM is a common internet abbreviation: For That Matter.

@jamesqf: OH! facepalm

@alephzero: 12K ft in 15 minutes is not exactly rapid. The internal pressure of a bear spray cannister is (per Google) about that of a bike tire, something that is going to experience much greater and faster pressure changes, from e.g. running over a rock. So it's perhaps a matter of comparing risks: I've never had (or heard of) bear spray going off accidentally. I have been charged by a bear, and have had other close encounters with them.

@Jpe61 accepted the other answer as it's more practical, but thanks a lot again for yours!

@user4867444 well it is a better answer 😃 Play it safe if you fly with bear spray 👍

Would a bear scarer/wildlife deterrent horn be a viable alternative, seeing as they don't use chemicals?

@AndrewMorton If by "viable alternative" you mean "allowed on a plane without much risk," then yes. If you mean "equally effective at preventing a bear from killing you," I'll defer to people with more expertise than myself, but my impression is that they would not.

@user4867444, I've got relatives who work in Yellowstone National Park. Accidental indoor discharges of bear spray happen several times a year, and can render a large room or even an entire building uninhabitable for an hour or more.

@Mark: Accidental how? The container discharges by itself, or because someone is playing around with it? Certainly the second happens: I knew a guy who wrecked his car because he was playing around with stuff his girlfriend had left in the console. Saw a cute little aerosol container and said to himself "Aha! Perfume, wonder what it smells like?" Wasn't perfume, was mace.

@jamesqf, someone sits on their bear spray and breaks off the valve, someone leaves the safety off for faster response and the trigger bangs against something, defective valve is just barely holding shut until the spray gets held just wrong, etc. There are all sorts of things that can go wrong.

@jamesqf nature finds a way. A small plane like a Cessna is a confined space, and any discharge is going to fill the cabin.

@Harper - Reinstate Monica: The question, though, is how likely that is, compared to all the other things that can go wrong when you're flying a small plane. Is it a realistic risk that you should consider, or something on the order of being struck by a falling meteorite? I mean, if we were really that concerned about eliminating absolutely every risk, we wouldn't be flying, nor would we be going to places where we might encounter bears, now would we?

The trick is to eliminate any and all risks that can be eliminated. General aviation is dagerous enough as it is, no need to add extra risk, however small they may be.

Exactly. Humans are infamously bad at estimating risk factors, just look at MCAS. The question is, what do you want on your tombstone, or more precisely, your NTSB report?