C.R.S. § 8-20-301: Unlawful use of container.

No person, firm, or corporation, except the owner thereof or persons authorized in writing by the owner, shall sell or offer for sale, or deliver any gas or gaseous compound used for heating or cooking, which is shipped, consigned, or delivered in steel containers, or containers made of other metal, plastic, or other substance, if such container bears upon the surface thereof, in plainly legible characters the name, initials, or trademark of the owner. The term "gas or gaseous compound" as used in this part 3 includes 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.