White silica gel is used: within the gas industry to dry herbal gas, as a desiccant in packaging (silica packets), for protecting shipment, electronics, vitamins, prescription drugs, foodstuffs. Silica gel would not expire inside the feel that it becomes harmful or unusable. however, its effectiveness as a desiccant diminishes while it absorbs moisture. once saturated, it is able to be reactivated with the aid of heating to drive off the absorbed water and used once more. to assess silica gel first-rate, you may take a look at for visible modifications in indicating silica gel (which turns coloration whilst saturated) or use a moisture analyzer to degree moisture content in non-indicating silica gel. Blue indicating silica gel will turn crimson or inexperienced because it absorbs moisture, while orange indicating silica gel will flip green.