Posted on 22 Jul 2015 19:08
Silica is Actually Added to Foods, Yet Silica Gel Dissicant Packets Say DO NOT EAT
I came across a comment about Rachael Ray saying that everyone should make their own taco seasoning mix instead of using store-bought packets, because they are full of sodium and they contain silica, the same stuff found in those ant-desiccant packets that say DO NOT EAT. First, the sodium stuff is so very tasty. It comes from the salt, and it is what makes the taco seasoning taste good.
I doubt you'd make a taco seasoning mix without salt, and therefore without sodium. And if you try one of those low-sodium brands, you'd probably want to add salt to it. But, the silica, that sounds poisonous. Surely that shouldn't be in our food.
Are Silica Gel Packs Poisonous?
The short answer is no, the silica gel anti-desiccant beads found in those little white packets are not poisonous, at least in an of themselves. So, why the warning? It's not food, for one thing, and you might choke on the beads. And, they are meant to absorb moisture, so, theoretically, at least, if you ingested enough of them, you could dry up like a shriveled old raisin. But likely not.
A common silica gel anti-desiccant packet,
torn open to show the beads inside
A common silica gel anti-desiccant packet, torn open to show the beads inside
There are some other caveats, however. If you open up packets of silica gel beads, you'll notice that some are clear but others have a striking blue color (see image below). This color comes from cobalt(II) chloride, which is used to help indicate when the silica is saturated, and cannot absorb any more moisture, at which point it turns pink. This is unlikely in the little white paper packets, as such a visual indicator would do little good if you couldn't see it. These are used in clear permeable containers.
There may be other chemicals present, as well, as pointed out on Mental Floss. But, just as the article says, the most probable reason for the warning is the same reason we see warnings on almost everything these days: The company that makes the packet is covering it's butt, and doesn't want to be sued by some silly person who gags himself on a silica bead. All this being said, please do not eat any silica gel beads!
Silica in Foods
The silica that I mentioned in taco seasoning mixes, is silicon dioxide. It is used in foods as an anti-caking agent and for other uses. In something like taco seasoning mix, it is to keep the powder from clumping together. Another more common silica food additive is sodium aluminosilicate, which is used in baked goods, cake mixes, salad dressings, ice cream, processed cheeses, dried coconut, and table salt.
Silica is abundant in the Earth's crust, making up 25% of it. Common minerals like quartz, feldspar, mica, and talc are all silicate minerals. An easy way to think of it, however, it simply to think of beach sand, the most common material of which is silicon dioxide, and this sand is formed from broken down quartz mineral.
Since silica is so common, it is present in pretty much all waters, and in every plant and animal, including in human tissues. Humans have around 100 grams of the mineral in the tissues of their bodies. This means that you are taking in silica in pretty much every food you eat, and even in the water you drink. The amount of silica you get from silica food additives added to food is miniscule in comparison to your overall intake.
The average intake of sodium aluminosilicate, which is water soluble, is around 0.3mg per kilogram of body weight, yet is has very low acute toxicity and there is no evidence that it builds up in tissues.
Other insoluble or only slightly soluble silica compounds are used in foods appear to be biologically inert, except for potassium and sodium silicates.
There are many silica compounds used directly in foods, or that may come into contact with foods such as from packaging. At this time, there is no reason to fear any health effects from these compounds in the amounts they are commonly used. There is little reason to suggest that no one should buy store-bought taco seasoning on the grounds that it contains silica, not to suggest that the public avoid other silica containing processed foods.