Silica Gel is an amorphous form of silicon dioxide, which is synthetically produced in the form of hard irregular granules (having the appearance of crystals). A micro porous structure of interlocking cavities gives a very high surface area. It is this structure that makes silica gel a high-capacity desiccant. The beauty of silica gel is the physical adsorption of water vapour into its internal pores. There is no chemical reaction, no by products or side effects. Even when saturated with water vapour, Silica Gel still has the appearance of a dry product, its shape unchanged.

Advantages of Silica Gel as a desiccant:

Silica Gel has many other properties that recommend it as a desiccant. It will adsorb up to one third of its own weight in water vapour. This adsorption efficiency is approximately 35% greater than typical desiccant clays, making Silica Gel the preferred choice where weight or efficiency are important factors.

It has an almost indefinite shelf life if stored in airtight conditions.

It can be regenerated and re-used if required. Gently heating silica gel will drive off the adsorbed moisture and leave it ready for re-use. It is a very inert material; it will not normally attack or corrode other materials and with the exception of strong alkalis and hydrofluoric acid is itself resistant to attack. It is non-toxic and non-flammable. It is most frequently and conveniently used packed in a breathable packet. These are available in a wide range of sizes suitable for use with a wide range of applications.

Standard White Silica Gel is referred to as being non-indicating. As it adsorbs moisture it remains physically unchanged. Indicating Blue Silica Gel are coloured Gels whose colour changes into pink as they adsorb moisture.