I want to run a Lego Pneumatic Engine on the CO2 that is produced, but before I do, I want to be sure that that's the ONLY gaseous product from a real-world reaction. Everyone seems to assume that it is, just by omission, but no one actually says it.
I'm sure it would run, but I'd rather not damage the ABS plastic or probably-steel parts (shiny metal piston shaft), or a rubber seal or the factory lubricant or something else that I can't see. CO2 seems inert enough by itself, but is that really ALL I'll get?
(assuming of course, that I keep the foam out)