nbri-pur-rc-rdc-2020 accumax. nbri-pur-rc-rdc-2020 hyclone. nbri-pur-rc-rdc-2020 krishgen. -1 carbon di-oxide (industrial grade/food grade filtered) 2 carbon di-oxide (medical grade filtered) purity 99.99 3 argon high purity (grade-i) purity >99.99 4 dissolved acetylene high purity without moisture 5 zero air high purity 6 helium analytical grade purity 99.999 7 nitrogen analytical grade purity 99.999 8 hydrogen analytical grade purity 99.999 9 carbon monoxide high purity 99.99 10 nitrous oxide high purity 99.99 11 oxygen analytical grade purity 99.999