Kɔstik soda (we dɛn kin kɔl bak sɔdiɔm haydroksayd) na wan industrial kemikal we dɛn kin yuz fɔ du bɔku tin ɛn we dɛn kin yuz bɔku bɔku wan we dɛn kin yuz na bɔku bɔku industri dɛn lɛk tɛkstayl, pulp ɛn pepa, alumina, sop ɛn ditajɛn, petrolium rifinin ɛn wata tritmɛnt. Dɛn kin sɛl am insay tu fizik stet dɛn: likwid (alkali) ɛn sɔlid (flɛks). Kɔstik soda flɛks izi fɔ transpɔt fɔ lɔng distans ɛn na di prɔdak we dɛn kin lɛk fɔ ɛkspɔt. Di kɔmni na di sɛkɔn big wan we de prodyuz kɔstik soda na India wit 1 milyɔn tan prodakshɔn kapasiti ɛvri ia.