used as the most common paint stripper on wooden objects.

used in conjunction with zinc for creation of the famous "Gold pennies" experiment.

is used in the refining of alumina containing ore (bauxite) to produce alumina (aluminium oxide) which is the raw material used to produce aluminium metal via the smelting process.

used in soap making (cold process soap, saponification).

Food uses of sodium hydroxide include washing or chemical peeling of fruits and vegetables

used in the home as a drain cleaning agent for clearing clogged drains.

used as a cleaner in breweries, where it is simply called "caustic".