Here's some Super Sentai moments where poisoned gas was used as a main plot or not... though this list I assume is pretty incomplete so feel free to throw in your comments on what I missed.
In Dynaman episode 47 (now only if I saw more of Dynaman than just some raw videos and the Dynaman parody dub), there's the Poison Gas Weasel monster. He was created to poison people but according to Power Rangers Wiki, the gas got tainted by the Retro Gene created by Professor Yumeno resulting to rather hilarious consequences.
In Bioman episode six, Dr. Man plans to set a rather genius trap that involved Mt. Taikyoku and having an underground trap. Dr. Man knew he can't face Bio Robo head on so he has Farrah create a trap that would release poison gas into the air. It was revealed to be a trap for Bio Robo from the beginning to the end of the episode.