Caustic soda (yomwe imadziwikanso kuti sodium hydroxide) ndi mankhwala ogwiritsidwa ntchito kwambiri m'mafakitale omwe amagwiritsidwa ntchito m'mafakitale osiyanasiyana kuphatikizapo nsalu, zamkati ndi mapepala, alumina, sopo ndi sopo, kuyeretsa mafuta ndi kuyeretsa madzi. Nthawi zambiri imagulitsidwa m'njira ziwiri: madzi (alkali) ndi olimba (flakes). Ma flakes a Caustic soda ndi osavuta kunyamula pamtunda wautali ndipo ndi omwe amakondedwa kutumiza kunja. Kampaniyi ndi yachiwiri padziko lonse lapansi yopanga ma toni miliyoni imodzi pachaka.