Gases, namely acetylene, carbon oxygen, carbon monoxide, carbon dioxide, helium, nitrogen, argon, argon mixtures, air, oxygen, chlorine, ethane, ethylene, hydrogen chloride, hydrogen sulfide, krypton, methane, neon, sulfur hexafluoride, xenon; industrial gases, namely gases for welding, cutting, purging, blanketing or heat treating; specialty gases, namely compressed gases for the pharmaceutical, biotechnology, chemical, petrochemical, environmental, food, semiconductor, or life science industries, gases used in cryo-freezing, carbonation, and hydrogenation; research gases, namely carrier and support gases and electron capture mixtures; calibration gases, namely pure gases and precision mixtures used in calibrating analytical instruments