There's WHAT in my toothpaste?

Check the ingredients in your favorite shampoo. Any 'sheep wool grease' listed? Is there sugar in your sunscreen.

Next time you condition your hair, why not put some purified sheep-wool grease on it? After that, brush your teeth with some glittery particles of rock. And if you go out in the sun, don't forget to slather sugar all over your body.

You'd never do any of that, you say? Too late. You probably already have.

Sheep-wool grease is called lanolin (LAN-uh-lin). People have used "wool wax" for centuries. Commercial hair conditioners, shampoos, skin creams, and soaps may include it to soften skin and hair. Lanolin is obtained by washing raw wool. The lanolin is then bleached and dried.

To help remove particles sticking to your teeth, toothpaste manufacturers add gritty ingredients. Common ones are minerals like mica, silica (which is silicon dioxide - that's what quartz is made of), or chalk. Some gel toothpastes for kids add mica in the form of sparkling shapes.

Sugar-coat yourself for the sun

Mica is a soft sedimentary rock that is mined in sheets. Some toothpastes include mica coated with the bright white mineral pigment, titanium dioxide. Cosmetic chemists call titanium dioxide a "pearling agent," because it makes the paste glossy and white. Since finely ground titanium dioxide partially reflects ultraviolet light, it's in sunscreens, too.

Sunscreens may also contain special sugars, like sorbitol (SORE-bih-tohl), because they attract moisture. Moisture is seen as beneficial to skin. Sorbitol was discovered by a French chemist in 1872. He was studying berries from the mountain-ash tree. Later, sorbitol was found in many fruits and seaweeds.

For almost 50 years, now, sorbitol has been sweetening, stabilizing, and keeping chocolate and other confections from drying out too quickly. (Look for sorbitol on a candy bar's list of ingredients.) It's almost as sweet as table sugar and has a cool, pleasant taste. It's now made from another common sugar, glucose.

Take another look at your shampoo's label. Look at several, in fact. Notice anything? The same three ingredients are in almost every one: sodium lauryl sulfate, methylparaben (meth-il-PAIR-uh-ben), and propylparaben (pro-pil-PAIR-uh-ben). What are they doing in there?

Methylparaben and propylparaben have been used for half a century. They are synthetic preservatives, and if you see one, you'll generally see the other. When combined, these white, odorless powders prevent most bacteria and fungi from spoiling a product. Manufacturers like this, because it means the products can stay on the shelf longer without spoiling.

Sodium lauryl sulfate (SLS) is a surfactant. The simplest way to describe what a surfactant does is to say that it "makes water wetter." Have you ever seen a water strider skimming across the surface of a puddle? The insect is riding on surface tension. Surfactants break down surface tension so the water can soak through things better and get at the dirt.

Since the 1950s, SLS has been a preferred cleansing agent in shampoos, toothpastes, mouthwashes - even household cleaners. But since it doesn't create many suds, foaming agents, like cocamide DEA, are added. Cocamide comes from coconuts.

Coconuts' milky juice and white meat appear in many dishes and desserts. The meat is pressed to make coconut oil, which is used to make cocamide DEA.

If you're trying to rid your hair of oily buildup, why put coconut oil on it? Cocamide DEA is a foam booster that helps the cleaning process. This clear or pale-yellow liquid also stabilizes shampoos and helps control its viscosity (thickness). Coconut oil also finds its way into soaps, synthetic rubber, and even cooking oils.

It's in toothpaste - and antifreeze

Call it glycerine or glycerol, this oily, sweet-tasting, edible ingredient appears in many mouthwashes, toothpastes, and even sunscreens. Glycerine attracts water, and gives products a glossy appearance.

It slows down moisture loss to make hair and skin feel softer, and keeps toothpaste from drying out. It used to be a common ingredient in soap, and can be made from animal and vegetable fats (coconut or olive oil, for instance).

Glycerine was discovered by Carl Scheele in 1779 when he heated olive oil mixed with red lead. Glycerine also shows up in baked goods and antifreeze. Mixed with sulfuric and nitric acids, it becomes a powerful explosive: nitroglycerine.

It took a few hundred years for benzoic acid to catch on in cosmetics. ("Cosmetics" refers to mouthwash, shampoo, and the like.) Herbalists in the 1500s used this material without knowing it, since it is found naturally in many herbs, roots, and berries. At some point, the resinous goo, benzoin gum, was discovered seeping from cuts made in the bark of an Asian tree called the storax. Later, this gum was used to make benzoic acid. One early (and popular) use of the dried, sticky gum was as a vanilla-scented ingredient in incense.

Useful in mouthwash or bug spray

Today, benzoic acid is used in mouthwashes, shampoos, and foods as a preservative. It keeps bacteria and yeasts from growing and spoiling products. It's also used to make dye, bug spray, and plastic.

Look closely at the ingredient list on many cosmetics, and you'll see something called PEG, followed by a number. PEG is not a girl's name, in this case. The letters stand for polyethylene glycol. Its specialty is that it attaches to fatty compounds. PEGs are often used in ointment bases and to lubricate skin. Paints, foods, pharmaceuticals, and cosmetics also use them. Each PEG compound has a number associated with it, such as PEG-80. Chemists recognize the number as the molecular weight of the substance. The molecular weight determines if a PEG is liquid or waxlike. PEGs with numbers under 1,000 are clear liquids. PEGs over 1,000, are waxy, white solids at room temperature.

(c) Copyright 1999. The Christian Science Publishing Society

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