Everyone knows the little bags with Silica Gel printer on it that are included with many new items. It says what’s inside is silica or silica gel, drying agent. But what is it and why do items have to be stored next to a drying agent? And why does the packaging say ‘Throw away, do not eat?’
Use of Silica Gel
Let’s explain what is silica gel and why is it used. Silica gel sachets should absorb and reduce the moisture in product packaging so that, Mold and unpleasant smell do not originate in the product. The bags contain 98 percent silicon dioxide (SiO2). This is suitable as a drying agent because it is very porous and has a very large inner surface. The product is available in different grain sizes, from fine powder to the balls.
The bags used in the package inserts contain many small, solid beads. One gram of silica gel has an internal surface area of 600 to 800 square meters. Depending on the ambient temperature and relative humidity, this can bind a gram of up to 36 percent of its own weight to moisture from the ambient air. This means that a silica gel bag with a weight of one gram can accumulate (adsorb) up to 0.36 grams of condensation or moisture on the surface. The moisture can also be removed from the gel by heating. This process is then called Desorption.
Can you recycle the bags?
Technically, Silica gel can be used again. Silica gel can be dried at 100 to 110 degrees and then used repeatedly. With the small pouches that are used as a package insert, however, this makes no sense, because they would first have to be taken from their pouch, which is made of air-permeable fleece, then heated and cooled and filled back into the pouches.
Silica gel is completely non-toxic. For this reason, it can also cause dryness in foods. And if the balls are accidentally swallowed, they will be excreted by the organism in the same way or will be filled with moisture.
The packaging instruction ‘Do not eat. Throw away’ is only there to avoid confusion with food. If silica gel were harmful to health or even toxic, not only would the warnings look different. The food will never be packed with Silica bags.
Blue Gel is Toxic
However, an exception is a variant of the silica gel, the so-called blue gel. Blue Gel is actually toxic. It is colored blue and changes color to pink when it gets wet. It contains the carcinogenic substance cobalt (II) chloride and is therefore largely no longer manufactured. It has been replaced by the non-toxic silica gel orange, which is non-toxic and turns green/blue after absorption of moisture.
Also Read- Is Solid Soap Hygienic?
Silica Gel as Air conditioner
With silica gel you could heat and cool in a climate-friendly way. The granulate gives off heat as soon as moisture builds up. It could be used as a heat store in the future. Initial practical tests are already underway. Soon, we might have the silica gel based Air conditioners.