User blog comment:MmmMeat/Smelly DF/@comment-3119203-20120419031529/@comment-4754162-20120419050152

^^ Agree! ^^

E.g.


 * A burst of CO to surrounding area to produce CO poisoning


 * A burst of CO2 to soffocate and cause nearby people to faint due to lack of O2


 * A burst of HCN (Hydrogen Cyanide) to produce cyanide poisoning

p.s. There are lots of different types of poison, and while Luffy may be immune to liquid poisons (e.g. those produced by Magellan or that taco swords(fish)man) he may not be immune to gas poisons, I think...