Silica gel is a substance made from silicon silicate that is known for its ability to absorb and hold in moisture. Even though the term silica gel is used to describe this particular type of silica substance, it is actually a solid rather than a gel. This silica is broken up into tiny beads or powder and is often used to draw in moisture from food products or items where excess moisture would be detrimental to the quality of the product. Many consumers find small packets of this sand-like substance inside leather products, pepperoni, and occasionally electronics. Some companies also put packets of the gel inside vitamins to prevent excess moisture from forming inside the capsules or pills.
The maximum amount of moisture that silica gel can absorb is roughly 40 percent of its total weight. Many people would probably guess that once silica gel has absorbed the maximum amount of moisture possible that it would be useless. Silica gel can actually be reused multiple times. To reuse this gel, it needs to be reheated to approximately 300 degrees F (150 C). Reheating the gel to this temperature dries up the moisture it has absorbed so that it can be used again.
Some people use silica gel for the purpose of drying out flowers. This method is often time-consuming, but many people prefer it over other types of flower preservation methods because the results tend to be better when silica gel is used. There is a type of silica called silica sand that is often used specifically for drying out flowers. People normally place their flowers inside an airtight container along with the silica sand for a short length of time. Silica sand wicks away moisture from inside flowers to keep them from drooping and losing their color.
Contrary to popular belief, silica gel is not actually toxic. Many people are under the impression that the gel is toxic because the packets that contain it often have labels on them that say, "Do not eat." Even though gel made from silica isn't considered toxic, people should avoid eating it because it could cause some digestive and respiratory upset. The gel could also become toxic depending on what it has absorbed. For example, if the silica was placed inside of a container that held some type of poisonous substance or a prescription medication that wasn't appropriate for everyone, eating the gel could be life-threatening because it might contain trace amounts of the poison or medicine.