Silica Gel traps water vapour to prevent rust, corrosion, mould, mildew, spoilage, fogging and condensation when used within closed spaces. Silica Gel does not become wet, or swell in size as it works to trap damaging moisture. Silica Gel under optimal conditions will adsorb up to 30% of its own weight. Our indicating silica gel is packaged loose in a resealable pouch and is available in orange or blue changing colour when it is no longer active.