Sure. Lots of bored scientists and/or speculative fiction writers have described various ways to make it work.
But not all breath weapons are fire. We have a dragon and it has a deadly weapon in its mouth. The Komodo dragon's bite kills with a deadly bioweapon variously composed of teeth, toxins, and pathogens that develop with super-speed; and like mythical dragons, they're immune to their own weapons. They are more than capable of killing a human; they can kill a water buffalo. Really not far off the mark as monsters go. Dragon = truth in advertising.