Butane is a colorless, odorless, and gaseous hydrocarbon. There are two types of Butane you can choose from in the making of BHO: N-Butane and Isobutane.
N-Butane is the regular kind of Butane. Meaning it’s as pure as it can be. Meanwhile, Isobutane is the isomer form of Butane. It has the same molecular formula as butane, but it differs in the arrangement of atoms in space. Most people prefer using N-Butane due to its purity. Isobutane may be cheaper, but it is more hazardous and toxic than N-Butane. Reading through community threads, a percentage of people use a 50-50 mix of both for balanced and efficient production.
Other types of Butane often come mixed with Propane. Always keep an eye out for the Butane you buy. Better yet, check the quality of the Butane purchased before using. Spray Butane on a mirror, wait for 10 minutes and check if there is a poor-smelling residue left over.