Silica gel is an amorphous form of silicon dioxide, which is synthetically produced in the form of hard irregular granules hard regular beads. It is the structure that makes silica gel a high capacity desiccant. Water molecules adhere to the Silica Gels surface because it exhibits a lower vapour pressure than the surrounding air. When equilibrium of equal pressure is reached, no more adsorption occured, thus the higher the humidity of the surrounding air, the greater the amount of water that is adsorbed before equilibrium is reached.
Silica gel is the physical adsorption of water vapour into its internal pores and 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. It is non-corrosive, odorless, tasteless, non-toxic, and chemically inert
Silica Gel is one of the oldest and most popular desiccant and adsorbent used for a wide number of industrial and consumer applications.
Silica gel is nearly harmless, which is why you find it in food products. Silica, or silicon dioxide (SiO2), is the same material found in quartz. The gel form contains millions of tiny pores that can adsorb and hold moisture. Silica gel is essentially porous sand.
Silica gel can adsorb about 40 percent of its weight in moisture and can take the relative humidity in a closed container down to about 40 percent, it prevents all forms of Rust, Corrosion, Oxidation, Mildew, Fungus, Mold, Condensation and etc.
The orange gel will turns to dark green when saturated with moisture.