Caustic soda (e tsejoang hape e le sodium hydroxide) ke k'hemik'hale ea indasteri e feto-fetohang le e sebelisoang haholo e sebelisoang liindastering tse fapaneng ho kenyeletsoa masela, pulp le pampiri, alumina, sesepa le sesepa sa ho hlatsoa, ​​​​ho hloekisa peterole le kalafo ea metsi. Hangata e rekisoa maemong a mabeli a 'mele: metsi (alkali) le a tiileng (li-flakes). Li-flakes tsa caustic soda li bonolo ho li tsamaisa libakeng tse telele 'me ke sehlahisoa se ratoang ho romelloa kantle ho naha. Khamphani ke mohlahisi oa bobeli oa caustic soda India ea nang le bokhoni ba tlhahiso ea selemo le selemo ba lithane tse limilione tse 1.