L

l

Abbreviation for liter.

labeling

The Cosmetic Labeling Act marked a major step in helping consumers become aware of what they put into their hair and rub onto their faces. Passed April 14, 1977, it requires that ingredients be listed, in descending order of concentration, on the labels of most cosmetics. Soap, however, is exempt, and flavors, fragrances and trade secrets don’t have to be listed specifically.

lactagogne

A substance that stimulates the breasts to produce milk.

lactalbumin

Because this natural milk protein is high in lactic acid and contains all eight of the essential amino acids, it’s an excellent ingredient for hair conditioners. The late Adelle Davis called it the most perfect protein.

lactic acid

This acid, which occurs naturally in milk, produces pH levels like those of the hair and skin; it also helps moisturize the skin naturally. See fruit acids.

lake colors

These solid forms of dyes are made by mixing liquid dye with an insoluble powder like aluminum oxide. They may be natural, but they’re usually synthetic and are made from coal tar. See colors.

lanolin

This yellow, semisolid, fatty secretion from sheep’s wool is used as an emulsifier, a base and an emollient.

Although Janolin is natural and is well absorbed by the skin, there have been some reports of allergic reactions.

lanolin alcohol

This solidfatty alcohol of lanolin is used as an emulsifier and thickener.

lanolin oil

This is lanolin with the wax component removed. It’s used as a moisturizer.

lanosterol

This sterol, derived from alcohol, is used as an emollient.

lapases

lapases

These lipolytic enzymes can hydrolyze fixed oils into glycerine and fatty acid components. Glycolic acid is an example.

lauramide DEA

This white, waxy, non ionic, synthetic chemical is used in shampoos, bubble baths and detergents as a surfactant and foam-builder. It may be mildly irritating to the skin, and may also be contaminated with nit rosamines. See alkyloamides.

alkyloamides.

laureth 1-40

This polyethylene glycol ether of lauryl alcohol is a

synthetic surfactant and foaming agent.

lauric acid

This mixture of fatty acids was originally obtained from the European laurel, but it’s now obtained from coconut and palm kernel oils. Lauric acid is used to make soaps. esters and laurvl alcohol. See fatty alcohols.

fatty alcohols.

lauryl alcohol

This fatty alcohol,

This fatty alcohol, often derived from coconut oil, is used to make anionic surfactants. It may be natural or synthetic.

laurylmyrist-oleamidosulfo-succinate

This synthetic fatty acid alcohol (plus sulfosuccinic acid) is used as a dispersant and a surfactant, usually in shampoos. It can cause allergic reactions, is haririful to the environment and should be avoided. See fatty alcohols.

fatty alcohols.

LD/50, etc.

etc.

See lethal dose.

lead acetate

This inorganic salt, made from lead monoxide and acetic acid, is used to dye hair (it was formerly also used as an astringent). It’s poisonous and a carcinogen.

lecithin

This naturally occurring mixture of stearic, palmitic and oleic acid compounds is used as an emulsWer and surfactant. High in the B vitamins choline and inositol, it’s found in egg yolk and manufactured from soy oil.

lentigo

This is a small spot of pigmentation on the skin that’s unrelated to sun exposure. It may develop into a malignancy.

lethal dose

In this test, used to determine the toxicity of a chemical, batches of 100—120 animals are fed, force-fed, injected with or otherwise exposed to doses of the chemical being tested. The doses increase until half the animals are dead, which indicates that the LD/50 (lethal dose, 50%) level has been reached.

Sometimes other levels of toxicity are also determined for example, LD/90 is the dose at which 90% of the animals die. These LD numbers are then used to sell the chemicals. Lethal dose tests are inhumane and unscientific.

leucine

One of the essential amino acids (i.e., it can’t be manufactured by the body). Leucine is found in hair and is included in some amino acid shampoos.

leukodernaa

This skin abnormality is characterized by a splotchy lack of pigment in bands or spots.

lime

The word lime on a cosmetics label can either refer to calcium oxide (often occurring with magnesia), a caustic substance that’s used as an alkalizer, or to the citrus fruit, which is used as an astringent or hair rinse.

limewater

See calcium hydroxide.

lina 1001

This fragrant alcohol occurs in many essential oils, especially bois de rose oil and coriander. It’s used as an aromatic.

Iinoleamide DEA

This synthetic chemical (ethanolamide of linoleic acid, plus diethanolamine) may be contaminated with nitrosamines). See alkyloamides.

linoleic acid

This essential fatty’ acid, found in cold-pressed oils, is used as an emulsWer in cosmetics.

lipases

These lipolytic enzymes hydrolyze fats or fixed oils into their glycerol and fatty acid components.

lipids

These materials—soluble in alcohol (and other solvents) but not in water—include fatty acids, fats, waxes, fixed oils, phosphatides, cerebrosides and sometimes steroids and carotenoids. Along with proteins and carbohydrates, lipids constitute the structure of cells. When used on the skin, they have a moisturizing and emollient action.

lipstick

This waxy coloring that’s applied to the lips may be natural or synthetic.

liter

A unit of volume in the metric system that’s about 6% larger than a quart. It’s abbreviated I.

locust bean gum

See gums.

loofah

This vegetable sponge is the skeleton of the loofah fruit (family Cucurbitaceae). Usually long and cylindrical, loofahs have a rough texture that’s excellent for the body but somewhat too rough for the face.

lye

This strong alkali, which is made by washing wood ashes in water, is a caustic chemical that’s used in drain cleaners to dissolve organic matter. In spite of its harshness, lye is sometimes used to make soaps. It’s also used in hair straighteners, where it can burn the outer layers of the scalp and even cause blindness. Chemically, lye is potassium hydroxide or sodium hydroxide.

lysine

One of the eight essential amino acids.