What is Silica Gel?
Silica Gel is a safe desiccant that manufacturers add in small packets to keep moisture from damaging certain food and commercial products. Due to its physical properties, silica Gel is a good drying agent for preventing corrosion, contamination, spoilage, and mould growth in many commodities and products. Silica Gel packets can be found in various products, from vitamin bottles to shoes to electronics.
Uses of Silica Gel
Silica Gel is a versatile substance used for personal and business purposes. The applications are listed below
1. Desiccants
Silica Gel is commonly used as a desiccant in the form of beads wrapped in a paper bag. In many products, moisture is a stimulant for deterioration, and mould growth and condensation can damage goods such as electronics. As vitamin pills show, condensation may also hasten the chemical disintegration process. As a result, putting Silica Gel packs in these products can help solve these issues while preserving the products for a longer time.
Silica Gel is also used to dry the air in industrial-level compressed air systems. The air from the industrial compressor passes through a layer of Silica Gel Beads. These beads absorb moisture in the air and protect against damage caused by moisture and condensation. Silica gel beads can also dry compressed air in railway locomotives, where ice and condensation in the brake air pipes can cause the brake’s failure. Silica Gel can also control humidity levels in library exhibitions, museums, and storage.
Other applications for Silica Gel include inhalation devices, diagnostic test strips, drug test kits, syringes, and hospital sanitation kits. Users can use a Humidity Indicator Card to keep track of the amount of moisture to which the goods have been exposed to monitor the performance of these Silica Gels.
2. Food Additives
Silica Gel, also known as hydrated silica or silica aerogel, is labelled as “Generally Recognised as Safe,” or “GRAS” by the United States Food and Drug Administration. It means that, with approval from the authorities, it is safe to add Silica Gel to any food product. In the United States, the amount of Silica Gel permitted in any food product is up to 2%. In the European Union, the maximum amount of Silica Gel allowed in food products is 5% concentration.
Silica gel packets can be used as an anti-caking agent, stabilizer, defoaming agent, carrier, absorbent, conditioning agent, filter aid, viscosity control agent, emulsifying chill-proofing agent, and anti-settling agent in food packaging.
3. Humidity Indicator
Silica Gel is also widely used as a moisture indicator, changing colour gradually as it transitions from a dry (anhydrous) to a wet (hydrated) state. Silica Gel has three colours: Orange, Blue, and White. The most common are methyl violet (orange) and cobalt (II) chloride (blue).
Cobalt (II) chloride is a deep blue compound that turns pink when wet, whereas Methyl Violet is an orange colour compound that turns green or colourless depending on its conditions. Both are, however, carcinogenic and toxic. Despite being toxic and carcinogenic, they are still considered safe for medicinal use in certain products.
Ways to Reuse Silica Gel
1. Dry Out Wet Electronics
Silica Gel can be reused to dry wet electronics such as handphones. First, remove the battery and memory card from the device and place them in a tight box with Silica Gel packets for at least 48 hours.
2. Natural Air Fresheners
Silica Gel can also be repurposed into a customised potpourri. To produce a customised potpourri, cut open the sachets and soak the Silica Gel in aromatic oils. Silica Gel can also add a beautiful touch to potpourri by drying flowers.
3. Rust and Tarnish Remover
Silica gel packets can also prevent rusting when kept in toolboxes, tackle boxes, or razor blade storage containers. Putting a few Silica Gel packets in jewellery boxes and with silverware may also help slow the effects of tarnishing.
4. Preserve Clothes Fabrics and Materials
Silica Gel can help preserve the fabrics and clothes in closets. Hence, placing a few packets of Silica Gel in the pockets of clothes, especially in leather items like coats, shoes, and handbags, can help maintain their condition. Moreover, Silica Gel can also help preserve luggage that is stored or in use.
5. Reactivating and Reusing
Silica Gel loses its effectiveness after absorbing moisture (up to 40% of its weight). However, the beads can be reactivated and reused multiple times. To reactivate the Silica Gel, spread the saturated Silica Gel beads thinly on a baking sheet and bake for 15 minutes at 79.4°C in a preheated oven. The heat from the oven will absorb moisture from the desiccant pack, which will help reactivate the Silica Gel. After that, place the desiccant bag in a zip lock bag upon removing it from the oven to keep moisture away, and the desiccant pack will be ready for use when needed.
Conclusion
Reusing Silica Gel packets can help to reduce waste. With so many uses for these packets, it is never difficult to find a way to repurpose them. Place Silica Gels on a cookie sheet in a 37.8°C oven for an hour if the Silica Gels are no longer functional. This will help the beads dry out so they can be reused again and again.
