SILICA GEL Silica gel is one of the most commonly used desiccants (absorbent) and consists of nanoporous Silicon Dioxide (SiO2), Magnesium Oxide (MgO), Iron Oxide (Fe2O3), Titanium Dioxide (TiO2) and Calcium Sulphate (CaSO4). Silica gel comes in the form of white beads with an average size of about 3 mm (1/8”). In this case, it is an unsaturated, non-toxic and non-flammable material. The open nanoporous structure with an average pore size of 2.4 - 2.5nm translates to a surface are