Blue silica gel possesses the adsorption and moisture-proof properties of fine-pore silica gel, characterized by turning purple and then light red as it absorbs moisture. It can indicate environmental humidity and visually show whether the silica gel needs to be replaced or regenerated.

Blue silica gel can be used alone for moisture absorption. Due to its color-changing feature, it is often used in combination with ordinary silica gel desiccants to indicate the extent of moisture absorption, thereby determining the relative humidity of the environment.