Industrial and scientific gases; industrial and scientific gas mixtures; chemicals and chemical products used in industry and science; gases and gas mixtures used in the hospitality industry; gases and gas mixtures used in hotels, pubs, and bars; gases in liquid, liquefied or dissolved form; protective gases; and methane, ethane, propane, butane, oxygen, oxygen-containing gases, nitrogen, hydrogen, carbon dioxide, carbon monoxide, nitric oxide, nitrous oxide, ammonia, acetylene, helium, neon, argon, krypton, ozone, radon, xenon, and mixtures of all the aforementioned gases