Narcotic gas. It's probably halothane.
Money Heist Season 3, Episode 6
{\i1}Halothane is a NARCOTIC gas{\i0}
Money Heist Season 3, Episode 6
Halothane, highly NARCOTIC.
Money Heist Season 3, Episode 6
{\i1}They're using NARCOTIC gas.{\i0}
Money Heist Season 3, Episode 6
Let's get the vehicles ready
with NARCOTIC gas.
Money Heist Season 1, Episode 4