Yeah, it can be nasty. Ammonia is a very common refrigerant for ice rinks here in Canada. Operators die every so often across the country due to undetected leaks.
Ammonia seems like a grid scale storage solution, not something we can distribute across people’s homes. Home storage we should start focused on thermal batteries since it’s highly proven technology that needs almost zero maintenance.
And when burned it produces high amounts of pollutants that are about as deadly. (Fixable with the application of enough catalizers, that are made of material that is more expensive than gold.)
Besides, differently from what the GP claims, it does need to be pressurized. It can indeed be used as a fertilizer, requiring careful application because if it's over-applied it's pretty deadly to any plant, and if applied incorrectly it can leak from the soil and become pretty deadly to anything above it.
But some people really do love the stuff and believe it's a solution to everything.
Just as with chlorine gas: Luckily, we're incredibly sensitive to the odor of even safe-ish trace quantities of the toxin, so the actual risk is dramatically mitigated in any environment where there's air mixing. Smell it, back away until you can't smell it, and you're a survivor.
Just don't, say, descend an elevator shaft into an un-ventilated sub-basement with ammonia storage.
The amount of inconsequentially small ammonia leaks which nevertheless the owner insists on a service technician fixing immediately because of the alarming odor, actually form most of the case against ammonia as a refrigerant, which it's otherwise well-suited to.
