The exception is VX. If that's involved all bets are off, but there is nothing in the news stories to suggest that it is. Perhaps no news is good news.
The irony is that after almost exactly a century of familiarity with these weapons, we've discovered their limitations - a force prepared with countermeasures is relatively safe - and their most effective use. That is as a weapon against an unprepared, i.e. civilian, population. That's what they're good for. They're terror weapons, they always were.
These are all cholinesterase inhibitors which is basically bug spray. Those used as weapons of war are uniquely designed to be lethal to mammals.
The point I am trying to make is if you have a factory that can make bug spray you have a factory that can make chemical agents that are particularly lethal to humans.
VX is a short range weapon, though, a local weapon
you cannot disperse it to kill all the people it could kill, it will dissipate
still, kill all who get it but, short range, short effective dispersement
the value of these is a a residue bomb, tied to an explosive, to kill those who arent killed by shrapnel or first responders who come aftter the large first blast
like a nuclear dirty bomb
still effective, but unable to be dispersed as designed
only 50 yard radius instead of 200 yards wide
like that matters to the people it hits...