T-lim cov xov xwm tseem ceeb:
A, tshuaj lom neeg, tsim roj thiab cov khoom siv tsis muaj zog hauv cov cua sov hauv nroog. Xws li dej, ammonia, roj, hydrocarbons, thiab lwm yam.
B, cov ntaub ntawv corrosive hauv kev tsim tshuaj lom neeg. Xws li cov ntshiab alkali, sulfuric acid, nitric acid, acetic acid, thiab lwm yam.
C, cua txias, cov khoom siv kub tsawg tsawg hauv kev tsim khoom. Xws li kua methane, kua nitrogen, kua pa oxygen thiab ntau yam neeg txias.