Mich. Comp. Laws § 429.111: Liquefied petroleum or carbonic gas containers; definitions.

Sec. 1.

As used in this act:

“Liquefied petroleum gas” means any material which is composed predominantly of any of the following hydrocarbons or mixtures of the same: Propane, propylene, butanes (normal butane and isobutane), and butylenes.

“Carbonic gas” means carbon dioxide.