Review: Why There's Antifreeze in Your Toothpaste: The Chemistry of Household Ingredients

Have you ever read the back of labels and wondered why sodium chloride is in your shampoo or why antifreeze is in your toothpaste? Ever wondered what the oft-maligned sodium lauryl sulfate and corn syrup are really made of?

This fascinating book will answer these questions and more.

Even if you are not a science buff, you will emerge with a deeper understanding of chemicals -- which will come in handy the next time you do your grocery shopping. You might even impress a few friends with your new knowledge.

At first glance, non-chemistry-minded readers might be taken aback when they see chemical structures and complicated scientific terms. (For this reviewer, it was a traumatic flashback to my junior college days where lessons were a hazy, chemical-induced whirl of acids and tongue-twisting concoctions.) Students will actually find it useful should they ever need a chemistry reference guide.

Field thankfully makes the book less intimidating by keeping the tone relaxed and non-academic. He begins by offering a quick lesson in reading structural formulas, if you dare.

Ingredients are divided into different categories such as preservatives, buffers, sweeteners, fats and emulsifiers. These are common "household" ingredients that you'll find in everyday products. From the familiar citric acid (used as a food additive) to titanium dioxide (used in sun block) to polyvinyl alcohol (used in hairsprays and shampoos), Field explains the uses of more than 150 compounds. Each is accompanied by a structural formula, synonym(s), description and variants.

Field breaks up the monotony with interesting nuggets of information throughout the book. Who knew that the sugar in soft drinks has been mostly replaced by high-fructose corn syrup because it is not price-controlled by the US government, and that it is sweeter so less is needed?

Regrettably Field does not delve into the health risk of consuming these ingredients. It would have been even more interesting if he had.

So why is antifreeze a component of toothpaste? It turns out that ingredients with antifreeze properties also have emulsifying and moisturising properties. These ingredients such as glycerin or propylene glycol are non-toxic. When used in toothpaste, glycerine "sweetens while keeping the paste from drying out when the cap is left off".