Used primarily in the semiconductor industry for etching silicon wafers due to its ability to dissolve glass and silicon oxides. Commonly applied in petroleum refining to catalyze alkylation processes for high-octane fuel production. Employed in metal cleaning and pickling to remove oxides and scale from stainless steel and other alloys. Utilized in the synthesis of various fluorine-containing compounds, including refrigerants and pharmaceuticals. Also used in laboratories to decompose mineral samples and siliceous materials for chemical analysis. Found in household rust removers and concrete cleaners, though in diluted forms due to its high toxicity. Requires extreme care in handling because of its ability to penetrate tissue and react with calcium in bones and blood.