Silica gel is a substance that absorbs moisture from the air. Silica gel is inert, non-toxic, non-corrosive and non-friable. When placed inside a desiccator these silica gel beads will act as a moisture sink, continuously absorbing any moisture that is in the air, or that has been released by the products stored inside the desiccator. Indicating silica gel beads are specially formulated to contain a color-changing moisture indicator that turns from blue to pale pink, indicating that the silica gels beads are saturated with moisture and can not absorb any additional moisture. When the silica gel has changed color to pale pink, it should be replaced with a fresh cartridge, or regenerated as discussed below.