Blue Silica Gel is similar to that of white silica gel with the only difference being its INDICATIVENESS. Blue Silica Gel changes its colour from blue to pink after absorbing moisture thereby indicating us that its used to its full capacity. Silica Gel is basically a moisture absorbant. It absorbs moisture as trees absorb carbon-di-oxide.It is a porous, granular form of silica. a microporous structure of interlocking cavities gives a very high surface area (800 sq.mtrs) per gm. It is this structure that makes silica gel a high capacity desiccant. Water molecules adhere to the gels surface because it exihibits a lower vapour pressure than the surrounding air. The beauty of silica gel is the physical absorption of water vapour into its internal pores. There is no chemical reaction or side effects. Even when saturated with water vapour, silica gel has the appearance of a dry product and its shape remains unchanged.