Argon ar Rare gases Cas no.: 7440-37-1 Einecs no.: 231-147-0 Un no.: un1006 Purity: 99.999%-99.9999% Dot class: 2.2 Appearance: colorless Grade standard: electron grade, industrial grade Preservative Argon is used to displace oxygen- and moisture-containing air in packaging material to extend the shelf-lives of the contents. Industrial processes Argon is used in various types of arc welding such as gas metal arc welding and gas tungsten arc welding. Lighting Semi-automatic pet bottle blowing machine bottle making machine bottle moulding machine.