Yes. The Geneva Convention bans it, but that's not to say that all countries have signed up to the Convention or that they abide by it.
The use of poisonous gas was only banned after ww1
poison gas was considered a war crime to use after ww1
Poison Gas.
Poison gas and blistered your skin and burned your eyes and that is the reason they wore gas masks
to poison stuff
BZ is a nerve gas thus banned by the UN
poison gas is no longer allowed in warfare.
poison
It was the Germans and it was Chlorine Gas
is a gas that kills people
your question lacks detail. some gases are poison, some aren't. depends what gas you are talking about
Halabja poison gas attack happened on 1988-03-16.