Subheading 281111: Hydrogen Fluoride (Hydrofluoric Acid)
Subheading 281112: Hydrogen Cyanide (Hydrocyanic Acid)
Subheading 281119: Inorganic Acids; other than Hydrogen Fluoride
Subheading 281121: Carbon Dioxide
Subheading 281122: Silicon Dioxide
Subheading 281129: Inorganic Oxygen Compounds; of Non-metals, N.E.C. in Item no. … etc.