A continuation of  a list and brief definition of commonly used ingredients in cosmetic formulations. Note: allergies may occur with the use of any chemical, essential oil, herb or spice. It is advisable to test a small area of the skin prior to using the product in the shower of bath. Many of these ingredients are used in major formulations, but are becoming more available for the hobbyist and small formulator.

Imidazolidinyl urea: A preservative that may be derived from eithermethanol, wood alcohol or allantoin. Kills harmful microorganisms. Itis nonirritating, nontoxic, and not a formaldehyde donor. If heated to high temperatures, such as over the boiling point, it does produce formaldehyde. Not to be confused with urea from bovine sources.

Iron oxide: A naturally occurring compound of iron and oxygen found ina wide range of colors from black to yellow. Used as a natural colorant.

Isopropyl alcohol: Dissolves oils; has antiseptic properties. Can be drying to the skin if used as a primaryi ngredient in a formulation.

Isopropyl lanolate: An emollient that acts as a wetting agent for cosmetic pigments. Appears as a binder for pressed powders and as a lubricant in lipsticks.

Isopropyl myristate: Used as an emollient and lubricant in preshaves, aftershaves, shampoos, bath oils, antiperspirants, deodorants, and various creams and lotions. More than 5 percent in a formulation can cause skin irritation and clog pores.

Isopropyl palmitate: Used in many moisturizing creams. It forms a thin layer on the skin and easily penetrates.

Jojoba oil: Simondsia chinensis is a thick, liquid wax extracted from the large, vanilla- shaped beans of a bush that grows in the arid climates of Arizona, southern California, and New Mexico. Jojoba oil is strikingly similar to human sebum and is able to effectively penetrate the skin. It is a natural cellular renewal ingredient as well as an excellent moisturizer.  Is an antioxidant and is good for treating acne and dry skin, as well as eczema and psoriasis.

Kaolin: A white clay used to give color and “slip” to powders. It also helps to gently absorb oil on the surface of the skin. Although commonly used in clay facial masks, it may be drying to the skin in this type of product.

Karite nutbutter: Oil from a native African tree. Anti-irritant. Traditionally used as a sunscreen, although the effectiveness as a UV blocker has not been laboratory proven. See also Shea butter.

Kukui oil: Oil from the Hawaiian kukui nut. Very emollient and moisturizing.

Lactic acid: One of the alphahydroxy acids; found in fermented milk. Helps to loosen “intercellular glue” holding dead skin cells onto surface of the skin. Reduces wrinkles and improves skin texture.

Laneth-10 acetate: Derived from lanolin. Acts as an emulsifier and a superfatting agent, and it has some humectant properties.

Lanolin: An oil extracted from the wool of sheep without causing any harm to the animal. It is one of the oils closest to human sebum, making it an excellent moisturizing ingredient. Lanolin is a natural emulsifier and humectant that absorbs water and holds it to the skin to help prevent dryness. Formerly believed to be a common allergen, it is now known to cause allergic reactions in only a very small percentage of people.

Lanolin alcohol: Used as a thickener for shampoos and bath gels. Gives many cosmetics a creamy texture and a high gloss.

Lanolin oil: “Dewaxed lanolin”; acts as a skin moisturizer and reduces stickiness of creams and lotions.  Also found in hair conditioners, fingernail conditioners, and skin cosmetics.

Lauramide DEA: Nonionic surfactant; builds and stabilizes foam in shampoos and bubble baths. Can be drying to the skin. Some people report allergic reactions.

Laureth-23: A nonionic surfactant found in shampoos.

Lavender: Promotes cell regeneration, antiseptic, insect repellent; in aromatherapy it is calming, stress reliever.

Lavender oil: The most versatile of all essential oils. Because of the high percentage of linalool that it contains, lavender oil is excellent for promoting healing and for balancing the skin. It is an antiseptic, analgesic, antibiotic, antidepressant, bactericide, decongestant, and sedative. It helps to reduce scarring and also stimulates the growth of new cells.

Lecithin: A thick, oily substance present in all living cells, whether animal or plant. A natural antioxidant, emulsifier, and emollient. Also a phospholipid with great water-binding ability. (It is able to bind 300 times its weight in water.) Occurs naturally in eggs, milk, sunflower seeds, soybeans, and some vegetables.

Lemon grass oil: An essential oil distilled from the grassy herb of the same name. It is purifying, refreshing, and hydrating.

Lemon oil: An essential oil that is pressed from the outer rind of  It is a mild bleach, which enables it to brighten dull skin and calm redness. It is also a natural astringent, antiseptic, and bactericide with the ability to stimulate the white corpuscles that defend the body.  The essential oil is used to regulate and control fluid accumulation and to bring balance to fluids in skin cells. Lemon also balances the pH of the skin by counteracting acidity
on its surface. It has an uplifting and refreshing effect when inhaled.

Magnesium: Occurs naturally in great quantity in the sea salts from the Dead Sea, some of the most beneficial salts known. Magnesium helps to remineralize and soothe the skin.

Magnesium aluminum silicate: A naturally occurring mineral that is commonly used to emulsify, thicken, and color cosmetics. Because of its enormous molecular size, it is not absorbed through the skin.

Magnesium carbonate: Found in powders and covering preparations.

Magnesium silicate: See Talc.

Magnesium stearate: A compound of magnesia (a naturally occurring white alkaline powder) and stearic acid used as a natural coloring agent.

Manganese: Occurs naturally in great quantity in the sea salts from the Dead Sea, some of the most beneficial salts known. Manganese is soothing and calming to the skin.

Manganese violet: A light violet powder; can be used around the eyes.

Matricaria oil: Known as azulene. An essential oil distilled from flowers of Matricaria chamomilla, or German camomile. One of its major components, chamazulene, is an effective anti-inflammatory that encourages healing. Another component, bisabolol, is a powerful antiseptic and antimicrobial. This oil also contains flavonoids, plant acids, fatty acids, amino acids, polysaccharides, salicylate derivatives, choline, and tannin. Azulene is extremely soothing to the skin and has a distinctive smell, much like fresh hay. Only tiny amounts of this powerful essential oil need to be used for product effectiveness.  Aromatherapists use it as an anti-inflammatory, analgesic, antidepressant, antifungal and disinfectant.  Excellent for the treatment of dry, reddened, burned, or sensitive skin.

Menthol: An antiseptic and anesthetic found in skin lotions and shave creams. Has been shown to cause adverse reactions when applied in high concentrations to the skin. (Also, never use menthol in bath products that are meant to be “soaking” products, as menthol and private parts do not go well together.)

Methylparaben: A derivative of PABA {para-aminobenzoic acid). Used as a preservative with antimicrobial abilities, it prevents the formation of bacteria. Nontoxic and nonirritating at .15 of 1 percent. Note: This ingredient, along with butylparaben and propylparaben, may be irritating to the skin if more than 5 percent is present in a formulation; there are many commercially made cosmetics that have such a high percentage, which explains the commonly held belief that the parabens are sensitizers.

Methyl salicylate: Oil of birch, or oil of wintergreen. Anti-irritant and disinfectant. Main constituent of wintergreen oil or made synthetically. Very cooling and relaxing, but irritating to mucous membrane.   Can be absorbed through the skin, and is highly toxic, even in small quantities.  Use in moderation.

Mica:  A naturally occurring silicate found in a variety of rocks. Easily distinguishable by its shape, it comes in thin, papery sheets, or in powdered form. Mica has a natural iridescence and varies in color from brownish green
and blue to colorless. It is used as a natural colorant and to impart softness to the skin.

Microcrystalline wax: Used as a stiffening and opacifying agent.

Milk: Moisturizing, Vitamins A, D, E & K.

Mineral oil: A by-product of the petroleum industry. A thinner form of petrolatum (i.e., Vaseline). Contrary to its name, this is an inert substance that does not contain any minerals, nutrients, or organic ingredients.  Forms an occlusive layer on the skin that “seals” it; extremely comedogenic when used as a primary ingredient in moisturizers, liquid foundation, and other cosmetics.

Montan wax: Often used in place of carnauba wax.

Mucopolysaccharides: A basic component of the skin. This gelatinous material helps maintain a moist environment for collagen, elastin, and dermal cells and provides support for connective tissue and mucous
membrane. Used as a humectant and skin softener in cosmetics.