Thats just because no butane should be used to extract essential oils that you plan to smoke. The fda didn't approve butane hash oil. That warning is just the manufacturer covering their ass by blatantly saying your an idiot if you smoke anything extracted with their product but they will gladly sell it to you by the case if you are that dumb. Its marketed to you as an extraction solvent. Nobody buys a case of butane for their lighters nor cares about how many times refined their lighter fluid is.
Theres a hundred other ways to extract cannabis concentrates. Many of them using no solvent or just water.
