Launching a chemical attack on anyone for any reason other than
Immediate fear of your lives is against the law.
Some states have an 'Avenues Of Escape' law that says even if you have to jump out a third story window, you have to vacate you OWN HOME rather than harming an intruder.
Force can only be used as an absloute last resort to save your life...
(Personally, I take my changes with a Jury!)
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I would consider good locks and concealment before I went to the extremes of launching chemical attack on someone there.
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Something as simple as blocking a chimney would create a smoke out effect...
And a chimney is a direct access point into any shelter if it can be reached....
(and anyone that hasn't built 'Survival' shelter that was earth sheltered, low to the ground, low observability, wasn't thinking...)
And would smell like smoke for some time to come, but could be reoccupied right away once cleared ventilated.
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If you use chemical weapons (Even non lethal ones) you are going to have to contend with the after effects...
And just in case you have never been in the military or worked the gas chamber,
Something like CS is NOT easy to get rid of!
You will be scrubbing your brains out for the next year trying to get rid of it since it settles EVERYWHERE and stays active even though it's not airborne!
Most people can't enter a military gas training chamber without weeping like a baby even after it's not been used for weeks...
On the other hand, since they are NOT illegal,
A couple of cases of these wouldn't be a bad thing to have laying around...
And before the crap starts raining down,
These ARE legal in my state for private citizens to own... If you can find them.
They are NOT explosives, and no more illegal than smoke canisters.
Sales are restricted by the manufacturers to 'Approved' agencies,
And since there isn't any laws regarding 'Approved' agencies,
That would be anyone that can come up with enough money to buy in volume...