M

magnesium

This lightweight mineral occurs abundantly in nature and is essential for nutrition, especially for the absorption of calcium and vitamin C.

magnesium aluminum silicate

This flaky white solid is used as an anticaking agent, filler, thickener and stabilizer in cosmetics, especially antiperspirant5~ creams and shaving creams. See aluminum chemicals in cosmetics.

magnesium oxide

Also known as magnesia, this compound is used as an inorganic color and abrasive.

magnesium silicate

Found naturally in talc, this compound is used as an anticaking agent.

magnesium stearate

This magnesium salt of stearic acid is used as a filler in cosmetics.

mannitol

This naturally sweet alcohol, found in plants, is used as a humectant.

mascara

The practice of applying black pigment to the eyebrows and eyelashes probably originated in Egypt 30 B.C. or earlier. The whiteness of the whites of the eyes was emphasized by the darkened eyelids, and the large, dark pupils appeared like black pools. The whole effect was striking.

The first black pigment used as mascara was kohl, originally made from the ash of frankincense, and later from powdered antimony. The Egyptians found that, in addition to adding to the natural beauty of their faces, both were soothing to the eyes.

Today, the FDA allows the use of pure vegetable colors, inorganic pigments like natural minerals and earth colors, and lake colors in mascara. Manufacturers must guarantee that minerals used in their cosmetics contain no more than two parts per million of any impurity such as arsenic, lead, copper, etc. Coal tar dyes are forbidden, even if the color is certified for use in cosmetics. See colors.

massage creams and oils

Massage creams and oils are popular today in aromatherapy matherapy massage, sports medicine and the facial and body massages given by aestheticians. Massage oils are usually made from a vegetable oil base. Jojoba oil has been used in more expensive massage oils and aromatherapy oils (as a carrying agent for the essential oils), but peanut oil is the most commonly used, because it’s less expensive.

Massage creams, which evolved out of the conventional cold creams, are usually simple in formula and often contain no humectants. They can be all-purpose or designed for a specific purpose. For example, a sports massage cream will probably have a heat-up and cool-down effect, which means that menthol and/or eucalyptus will be added to the basic formula.

Massage creams should have enough "slip" so that the hands glide smoothly over the body. At the same time, they will be absorbed (though more slowly than moisturizing creams).

mateha

See green tea.

MEA

See monoethanolamine.

melanin

This dark brown or black pigment is found in varying amounts in animals and plants. Believed to be a type of polymer related to indole, it can be derived from the amino acids tyrosine or 1-dopa.

menstruums

Solvents, such as alcohol, acetone and water, that are used to extract essential oils from plants.

menthol

This oleoresin, derived from peppermint, is an excellent counterirritant and has soothing properties if used in concentrations of 1% or less.

mercury and its compounds

Mercury is a deadly poison, a heavy metal that accumulates in the body and may cause a wide variety of symptoms. Its use in dental amalgam (a silver and mercury mixture used to fill cavities) is suspected of being a health hazard, as mercury vapor is released during chewing. Ammoniated mercury was used in bleaching cream for decades until pressure from Japan and consumer groups forced its removal. Phenylmercuric acetate is a highly toxic chemical used as a preservative in eye cosmetics, although it doesn’t protect users from products contaminated with bacteria during use.

metallic salts

Used in men’s hair restorers, these are the oldest known hair dyes. They work by coating the hair with a metallic sheath that leaves the hair dull and dry-looking. Metallic salt dyes give inconsistent and unpredictable results, and they’re incompatible with permanent waves. Another toxic chemical used in some hair restorers is lead acetate.

Met hanal

A trade name for formaldehyde.

methanol

A colorless, flammable, toxic alcohol. It’s also known as methyl alcohol or wood alcohol.

methyl acetate

This ester of methanol and acetic acid is a synthetic chemical used as an aromatic and solvent. It can cause dryness and dermatitis.

methyl alcohol

See methanol.

met hylcellu lose

See cellulose gum.

methyl salicylate

This compound, which is used as a flavoring, aromataromatic, local anesthetic and anti-inflammatory, is the major constituent of wintergreen oil and sweet birch oil (at concentrations of around 98%), but it can also be produced synthetically.

mg

The abbreviation for milligram.

mg/kg

Milligrams per kilogram.

mica

This group of somewhat shiny silicate minerals that split into very thin sheets is used in eye cosmetics to provide sparkle.

microcrystalline wax

See waxes.

milk protein

Also known as lactalbumin, milk protein is derived from whey and consists largely of casein. It’s used in natural hair conditioners. See lactalbumin.

milligram

A unit of weight in the metric system equal to a thousandth of a gram.

milliliter

A unit of volunrn in the metric system equal to a thousandth of a liter.

mineral oil

A liquid mixture of hydrocarbons obtained from petroleum. Allergic reactions have been reported when mineral oil is used topically, and it may be phototoxic.

mineral spirits

This flammable petroleum distillate, which is lighter than kerosene, is used as a solvent.

mineral water

Water that’s drawn from a natural spring, and which may have therapeutic properties.

minimal erythermal dose

The amount of time in the sun that produces a sunburn (it varies from skin type to skin type).

mink oil

Another self-proclaimed miracle moisturizing ingredient, obtained from minks. Vegetable oils are just as good and animals aren’t killed to obtain them.

MIPA

See alkyloamides.

miscible

Able to be mixed with.

ml

The abbreviation for milliliter.

ml/kg

Milliliters per kilogram.

ml/l

Milliliters per liter.

moisturizer

moisturizer

A substance that, when used externally on the hair or skin, raises the moisture content.

moie

A small, raised spot, mark or protuberance on the skin, usually pigmented.

moiecuie

The smallest unit of any substance that contains all the properties of that substance.

monoethanoiamine (MEA)

This liquid amino alcohol is used as an humectant and emulsfler in cosmetics. It may be contaminated with nitrosamines. See alkyloamides.

monoisopropanoiamides

monoisopropanoiamides

See alkyloamides.

monoxide

A chemical compound that contains a single atom of oxygen in each molecule.

montan wax

See waxes.

montmoriiionite

A clay mineral used in facial masks.

mordant

A substance—such as alum, phenol or aniline oil— which fixes the dye used in coloring.

morpholine

This amine, made from ethylene oxide and ammonia, is used as a solvent and emulsifying agent.

mucilaginous

Soothing to irritated or swollen skin.

mucopolysaccharide

This class of hexosamine-containing polysaccharicles, widely distributed in the human body (as well as in the cells of other animals and plants), binds with water to form the thick, jelly-like material that cements cells together and lubricates joints. (The name was coined by K. Meyer in 1938, at the Cold Springs Harbor Symposium in Quantitative Biology.) The simplest molecule of mucopolvsaccharide that is able to penetrate the skin is laluramina.

musk

An animal or vegetable substance used as a fixative in perfumes. Animal musk is obtained from a sac situated under the skin of the abdomen of the male musk deer, or from other animals like the musk-ox, civet cat and muskrat. Herbal (vegetable) musk is obtained from the musk seed (hibiscus abelmuschus), the ambrette seed (Abelmoschus moschatus), the musk mallow or the musk clover.

myristalkonium chloride

This quaternary ammonium salt, made from myristic acid, is used as a surfactant, antiseptic and preservative.

myristw acid

This fatty acid, found in nutmeg, coconut oil and sperm oil, is used in cosmetics as an emulsifier and foaming agent. It’s also called tetradecanoic acid.

myristyl alcohol

Afatty alcohol derived from myristic acid.

myristyl lactate

This ester of myristyl alcohol and lactic acid is used as an emollient. See fatty acid esters.