Explanatory notes
… hydroxide (caustic soda) (NaOH) should not be confused with commercial soda, which is sodium carbonate ( heading 28.36 … of the lignin, manufacture of regenerated cellulose, mercerising of cotton, tantalum or niobium metallurgy, … chemical products, including phenolic compounds (phenol, resorcinol, alizarin, etc.). The heading excludes residual …