Explanatory notes
… (NaOH) should not be confused with commercial soda, which is sodium carbonate ( heading 28.36 ). Sodium hydroxide is … of the lignin, manufacture of regenerated cellulose, mercerising of cotton, tantalum or niobium metallurgy, … similar to the sodium hydroxide described above. It must be distinguished from potassium carbonate ( heading 28.36 ) or …