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What happens if you eat a silica gel packet? - Vivian Jiang
What happens if you eat a silica gel packet? - Vivian Jiang
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0:06
Of the many, many things we’re not supposed to snack on,
0:10
perhaps the most common forbidden food is silica gel.
0:15
This tiny packet pops up in packaging for everything—
0:20
from TVs and guitar cases to sunscreen and snack foods.
0:24
So why is silica gel everywhere,
0:27
and what would actually happen if you ate it?
0:31
Found in the Earth’s crust, silica, also called silicon dioxide,
0:36
is typically mined as raw silica sand,
0:40
which is then washed, dried, sifted, and chemically treated.
0:45
Once manufacturers ensure each grain is uniform,
0:49
the processed sand gets mixed with sodium carbonate,
0:53
then heated and combined with an acid that links the silica particles
0:58
into a jelly-like matrix.
1:01
This matrix gives the material its porous structure,
1:04
which stays stable after being washed and dried into hard, glassy beads.
1:10
The final product is chemically identical to the sand you might find on a beach—
1:16
the only difference is that porous structure.
1:20
Inside each silica gel bead is a massive microscopic network of tunnels.
1:26
This dramatically increases the surface area of each bead,
1:31
with a single gram of silica
1:34
offering over 700 square meters of surface area.
1:40
But this space doesn’t stay empty for long.
1:43
The silicon dioxide molecules that make up the gel
1:47
are held together by polar covalent bonds,
1:51
which attract other polar substances, including water.
1:55
So when silica gel is placed in a humid environment,
1:59
the water in the air is drawn to the beads’ surface.
2:03
From these surface pores,
2:05
the water vapor is then pulled inside the grain
2:09
through a process called capillary condensation.
2:13
Each grain can hold up to 40% of its own weight in water,
2:18
allowing a standard 5-gram packet to hold roughly 2 grams of liquid.
2:24
And since this liquid is held inside the bead’s internal network,
2:29
even fully saturated silica doesn't feel wet to the touch.
2:35
This ability makes silica gel a desiccant,
2:39
a type of substance used to keep things dry.
2:43
But these beads can suck up more than just water.
2:46
Silica attracts ammonia, sulfur dioxide, and a handful of other gases,
2:52
making it useful in gas masks and other filtration systems.
2:57
The pace of this process depends on the environment.
3:00
In a very humid enclosed space,
3:03
a packet could reach its saturation point within a day or two,
3:07
but this could take up to a week in a moderately humid environment.
3:12
Either way, silica gel beads functionally last forever
3:16
since you can dry them out in a hot oven.
3:20
These abilities and silica’s prevalence in Earth’s crust
3:24
have made it the planet’s most popular commercial desiccant
3:28
since we started mass producing it in 1919.
3:31
At home, it keeps snacks crispy and extends their shelf life,
3:36
ensures pills and vitamins stay dry,
3:38
and captures any stinky scents from your cat’s litter box.
3:43
Museums use silica gel in exhibit cases to prevent metal artifacts from rusting
3:49
and preserved animals from growing mold.
3:52
And in outer space, a form of silica gel called aerogel
3:57
is used to insulate rovers from extreme temperatures
4:01
and capture high-velocity comet dust for study back home.
4:07
But what about what silica gel would do to you
4:10
if you successfully swallowed a packet?
4:13
The answer is... not much.
4:16
Those “Do Not Eat” warnings have more to do with packets being choking hazards
4:21
than any silica-specific concerns.
4:24
Besides, your body has so much liquid in it—
4:28
even if the packet did suck up the standard 2 grams,
4:32
you could replenish that much and more with a single glass of water.
4:36
And since silica is chemically inert,
4:39
your body won’t break the gel down into something toxic.
4:43
That said, downing larger quantities of silica gel would be unpleasant.
4:48
Its moisture-wicking properties could dry and irritate mucous membranes
4:54
along the digestive tract,
4:56
resulting in diarrhea and an upset stomach.
4:59
Worse still, some silica is coated with cobalt chloride
5:04
to indicate moisture levels,
5:06
and that compound actually is toxic.
5:10
But assuming your silica snack is of the standard variety,
5:14
you should survive the ordeal.
