Hydrogen H2 Industrial Gases CAS No.: 1333-74-0 EINECS No.: 215-605-7 UN No.: UN1049 Purity: 99.995%-99.999% Dot Class: 2.1 Appearance: Colorless, flammable, odorless gas. Grade Standard: Industrial Grade, Medical Grade, Electronic Grade. Industry Use: In the high temperature glass manufacturing process and in the production of electronic microchips. Medical Use: Offer for treating kinds of disease, such as tumour, stroke. In semiconductor fabrication: Carrier gas, especially for silicon deposition gas chromatography.