What Happens If You Eat Silica Gel Beads?

Are Silica Beads Poisonous?

Silica gel is a type of silicon dioxide that is used to control humidity. Although it is called a gel, silica gel actually is a solid. It's usually non-toxic, despite the warning label.
Silica gel is a type of silicon dioxide that is used to control humidity. Although it is called a gel, silica gel actually is a solid. It's usually non-toxic, despite the warning label. Thomas J Peterson / Getty Images

Question: What Happens If You Eat Silica Gel Beads?

Silica gel beads are found in those little packets accompanying shoes, clothing and some snacks. The packets contain round or granular bits of silica, which is called a gel but is really a solid. The containers typically carry dire "Do Not Eat" and "Keep Away from Children" warnings. So, what happens if you eat silica?

Answer: Usually, nothing happens if you eat silica gel.

In fact, you eat it all the time. Silica is added to improve flow in powdered foods. It occurs naturally in water, where it may help confer resistance against developing senility. Silica is just another name for silicon dioxide, the main component of sand, glass, and quartz. If you eat it, it won't be digested, so it will pass through the gastrointestinal tract to be excreted in feces.

Yet, if silica is harmless to eat, why do the packets carry the warning? The answer is that some silica contains toxic additives. For example, silica gel beads may contain toxic and potentially carcinogenic cobalt(II) chloride, which is added as a moisture indicator. You can recognize silica containing cobalt chloride because it will be colored blue (dry) or pink (hydrated). Another common moisture indicator is methyl violet, which is orange (dry) or green (hydrated). Methyl violet is a mutagen and mitotic poison.

While you can expect most silica you encounter will be non-toxic, ingestion of a colored product warrants a call to Poison Control.

How Silica Gel Works

In order to understand how silica gel is, let's take a closer look at what exactly it is. Silica is synthesized into a vitreous (glassy) form that contains nanopores.

When it's made, it is suspended in a liquid, so it's truly a gel, much like gelatin or agar. When it's dried, you get a hard, granular material called a silica xerogel. The substance is used as granules or beads, where it can be packaged in paper or another breathable material to remove humidity.

The pores in the xerogel are about 2.4 nanometers in diameter. They have a high affinity for water molecules. Moisture gets trapped in the beads, helping to control spoiling and limit chemical reactions with water. Once the pores fill up with water, the beads are useless, except for decorative purposes. However, you can recharge them.

Re-Using Silica

Silica can be used in many interesting projects, plus you can recycle it to renew its desiccant properties. All you need to do it heat the gel in a warm oven (anything over the boiling point of water, which is 100°C or 212°F, so a 250°F oven is fine). Let the beads cool slightly and then store them in a water-proof container.

Silica Gel Fun Fact

Silica gel was important in World War II. It was used to keep penicillin dry, as a catalyst to make high octane gasoline, to make synthetic rubber, and to absorb toxic gases in gas masks.