| Harmonised Commodity Description and Coding System (HS) - level 2 - Chapter | 28 | Inorganic chemicals; organic or inorganic compounds of precious metals, of rare-earth metals, of radioactive elements or of isotopes | 
                
                  
                    | Harmonised Commodity Description and Coding System (HS) - level 4 - Article | 280511 | Sodium | 
                
                  
                    | Harmonised Commodity Description and Coding System (HS) - level 4 - Article | 280512 | Calcium | 
                
                  
                    | Harmonised Commodity Description and Coding System (HS) - level 4 - Article | 280519 | Alkali or alkaline-earth metals (excl. sodium and calcium) | 
                
                  
                    | Harmonised Commodity Description and Coding System (HS) - level 4 - Article | 280530 | Rare-earth metals, scandium and yttrium, whether or not intermixed or interalloyed | 
                
                  
                    | Harmonised Commodity Description and Coding System (HS) - level 4 - Article | 280540 | Mercury |