Ca(HSO3)2 is a white solid at room temperature, density 1.06 g/cm³. It is hazardous to human and the environment, and soluble in water. Ca(HSO3)2 is easy to decompose after heating.

Ca(HSO3)2 example reactions:
• 2SO2 + Ca(OH)2 = Ca(HSO3)2

Usage: paper industry etc