Narcojet does have "Injection" listed as its only vector, however, so may not be allowed as a gas attack.
This is (or was, rather) what made DMSO so popular, and why I loves me some Injector Dart rounds for shotguns.
Maybe the 5E armory book will include some kind of bee-hive type grenade/mine. *nudge nudge, to whoever*.
Kamikaze in gas form can also be useful, if delivered surreptitiously, in dealing with a security watch-station or bunkroom, or any gang hangout. Without a clear target, otherwise elite troops can be transformed into over-armed weefle-runners with attitude problems. This is, admittedly, a dangerous tactic, for what should be obvious reasons, but it could potentially leave a majority of a security shift hospitalized or on disciplinary leave, and replaced by overworked members pulled from other shifts, or hastily contracted mercenaries (who will lack a home turf advantage). The reduced surprise factor may be worth it, especially if the opposition is known to make use of paracritters requiring handlers.