I

inaidazolidinyl urea
A by-product of human metabolism used as an anti-microbial agent.

indigotine
The common name for uncertified FD&C Blue No. 2. (see also FD&C Colors)

indium
An ionic plant source trace mineral.

inflammation
A condition of the skin characterized by fever, redness, swelling, pain or itching and failure of the function of that body part or system.

infusion
Tea made by steeping the leaves or flowers of an herb in hot water.

inorganic
Being composed of matter other than plant or animal, like minerals.

Inositol “vitamin B”
An emollient that helps prevent thinning hair.

iron
Iron is a mineral that occurs in both plant and animal tissue. Its major function is to combine with protein and copper to make hemoglobin. Hemoglobin transports oxygen in the blood from the lungs to the tissues, which need oxygen to maintain basic life functions. Iron builds up the quality of the blood and increases resistance to stress and disease. It is also necessary for the formation of myoglobin, which is found only in muscle tissue. Myoglobin supplies oxygen to muscle cells for use in the chemical reaction that results in muscle contraction. Iron also prevents fatigue and promotes good skin tone.

iron oxides
Natural oxides of iron “iron combined with oxygen” varying in color from red to brown and black to orange or yellow, depending on the degree of water added. These are inorganic pigments approved for cosmetic use, including the eye area.

irritant
A substance that consistently and predictably produces an adverse response such as swelling, reddening, itching, burning, or blistering in virtually all of the population. Irritants are not the same as allergens.

isopropanol “isopropyl alcohol”
An organic solvent of the alcohol family. Used to solubilize resins, polymers, and other fatty ingredients. Also used in hair coloring to dissolve oxidation dyes.

isopropyl alcohol
See “isopropanol”.

isopropyl lanolate
A synthetic moisturizer.

isopropyl myristate
This is a synthetically made emollient and lubricant that is used to replace oilier ingredients and reduce the greasy feel of products.

isopropyl palmitate
An ester of palmitic acid from coconut oil used to impart silkiness to the skin and hair.

isotonic
Having the same salinity as body fluids.

ivy
A mild irritant botanical with toning and tightening properties. It is believed to stimulate blood circulation to the areas on which it is applied.

ivy extract
A natural diuretic and cleansing extract that is used for its skin firming and tightening actions.

K

kaolin clay
White powder clay obtained from kaolin in southeast China. Also known as china clay, this fine mineral-rich powder helps to draw oils from pores while ridding the skin surface of dead cells and dirt.

kelp
Kelp contains nearly thirty minerals that nourish the glands, particularly the thyroid and pituitary. By enhancing the action of the glandular system, it helps to balance the body’s metabolism and the rate at which the body burns calories. Kelp is also an important nutritive tonic herb that aids in the treatment of obesity, heart disease, respiratory disease, rheumatism and arthritis, high blood pressure, thyroid deficiency, constipation and gastrointestinal ailments, and infectious disease. Kelp provides nutritive support to the entire body and also improves circulatory stimulation.

keratin
This insoluble albumoid “fiber protein” can be found in stratum corneum cells like hair, hoof, horn, and nails. High in sulfur, keratin is strong, but subject to chemical penetration. A surface protective agent with film forming and moisturizing action.

keratinization
The process by which the epidermis forms its outer protective layer, the stratum corneum. Conversion into keratin or keratinous tissue.

keratinocyte
Epidermal skin cell that makes keratin and eventually becomes a dead, flattened cell of the stratum corneum.

keratosis
A skin lesion that is abnormally sensitive to the effects of ultraviolet light “sunlight”. Usually a discreet, slightly raised red or pink lesion located in a sun-exposed surface. The texture of the lesion may be rough, gritty or scaly.

keratohyalin granule
Granule contained in the granular cell layer of the epidermis. Contains the protein filaggrin, which is a basic protein component of keratohyalin granules of the suprabasal cells of the skin.

ketones
What we call ketones are really two acids and a ketone. The acids are called hydroxybutyric and acetoacetic. Butyric is related to butter because it's formed in rancid butter from the milk fat. Acetoacetic is related to the acid in vinegar. The ketone is acetone, the same that is use to clean up nail polish.

KOH “potassium hydroxide, KOH”
A caustic white solid alkali, KOH is used in the manufacturing of soft or liquid soaps.

kojik acid
A skin-lightening agent used to treat hyperpigmentation.

L

Labeling “cosmetics”
The Cosmetic Labeling Act or Fair Packaging and Labeling Act, means that customers are allowed to be informed of what are in the hair and skin products they use. Passed April 14, 1977, it requires that most ingredients be listed in descending order of concentration, on the labels of most cosmetics. Soap is excluded and flavors, fragrances and trade secrets do no have to be listed specifically.

lactalbumin
A natural milk high in lactic acid and consisting of eight amino acids. Used in hair conditions for dry or damaged hair, it has been labeled “the most perfect protein”.

lactamide MEA
See “acetamide MEA”.

lactic acid
An alpha-hydroxy acid extracted from milk, though most forms used in cosmetics are synthetic. An acid naturally occurring in milk that produces pH levels similar to those of the hair and skin, helping to moisturize the skin naturally. Exfoliates cells on the surface of the skin by breaking down the material that holds skin cells together. It may irritate mucous membranes and cause irritation – see also “AHAs”. Lactic acid is an alpha-hydroxy acid with three carbons, thus it helps diminish the cohesion of surface skin cells “assists in cell detachment from the lower layers of the stratum corneum” and prevents thickening of the stratum corneum. This results in smoother, more flexible skin. Lactic acid also has a larger molecular size than glycolic acid and is absorbed more gradually across the epidermis with less irritation.

lake colors
These solid forms of dyes are made by mixing liquid dye with an insoluble powder like aluminum oxide. Natural, but usually manufactured and made from coal tar. Dyes that do not dissolve in water result in less color leaching.

lamellar granule
Small oval granule produced in the prickle cell layer that contains mainly lipids.

laneth-10 acetate
The polyethylene glycol ether derived from lanolin. Used as an emulsifier and emollient to soften skin.

langerhans cell
Epidermal cell that is an important immunologic defender. The Langerhans cell is dendritic in shape and located in the stratum spinosum of the skin. It is involved with the mononuclear phagocytic system to process and present foreign antibody to the immune system.

lanolin alcohols
Distilled and deodorized solid with excellent emolliency properties for skin and hair. Contains up to 30% cholesterol and related sterols.

lauramide DEA
This white, waxy, nonionic, artificial chemical is used in detergents as a surfactant and foam builder. This mixture of ethanolamides of lauric acid may be mildly irritating to the skin.

laureth-3
This is the polyethylene glycol ether of lauryl alcohol, principal alcohol of coconut oil. It is used to soften and smooth skin and as a thickening agent.

laureth-23
The polyethylene glycol ether of lauryl alcohol used as a thickening agent or emulsifier.

laureths
Substances that in various combinations create a wide range of mild detergent cleansing agents called surfactants. See also “surfactant”.

lauric acid
A crystalline fatty acid occurring as glycerides in natural fats and oils, especially coconut and palm kernel. Used in making soaps, esters, and lauryl alcohol.

lauroamphocarboxyglycinate
Mild, foaming amphoteric organic compound used as a skin surface-cleansing agent in shampoos and facial cleansers.

lauryl alcohol
This fatty alcohol, often derived from coconut oil, is used to make anionic surfactants. May be natural or man-made.

lavender extract and oil
Used primarily as a fragrance, though it may have antibacterial, anti-inflammatory and skin soothing properties.

lavender essential oil “lavendula offinalis”
An essential oil with a great many beneficial properties including skin healing, antibacterial, antiviral, analgesic, a mild sedative and good for headaches, nausea, vomiting and colic. Said to be gentle enough for use on babies.

lecithin
Used as a water-binding agent in lotions and creams, lecithin is a natural yellow phospholipid with antioxidant, emulsifying and emollient properties. Found in egg yolk and in the membranes of other plant and animal cells, lecithin helps to protect and soften the skin and to replenish the acid mantle. Considered a valuable natural emulsifier in cosmetic products.

lemon oil
From the fruit of the citrus lemon, lemon oil is known for its astringent and anti-irritant qualities. Used for its antiseptic properties as well as its detoxifying effects.

lemon extract
Lemon extract is refreshing and purifying to the skin. It is extremely active when applied to an oily skin condition. Lemon extract is a natural purifier, cleanser, astringent, decongestant and tonic. It can also help prevent skin discoloration.

lemongrass
Lemongrass is used to add sheen. It is also cleansing and used as an elasticizer in hairsprays.

lemongrass oil
Cleansing and purifying to the skin, lemongrass oil is used for its excellent antiseptic properties. High in vitamin A, this oil helps normalize oil production and reduce breakouts. Can also be an effective mosquito repellant.

lemon thyme
An aromatic, antiseptic, diaphoretic, stimulant, disinfectant that has many useful applications. Helps to soothe and smooth skin.

lichenification
Thickening of the epidermis that causes skin to look dry and leathery where normal skin markings are exaggerated. Repeated rubbing and scratching can produce lichenification.

licorice extract
Inhibits melanin biosynthesis while scavenging free radicals “antioxidant”. Treats acne and calms allergic skin.

licorice root
Great facial steaming herb used to open and soothe the pores so that other herbs may cleanse and medicate them.

lime oil
Lime oil shares many of the qualities of lemon oil including antiseptic and restorative properties.

liniment
A topical liquid “alcohol, oil or water preparation” containing therapeutic agents for topical application.

linoleic acid
A liquid unsaturated fatty acid found especially in semi-drying oils like peanut oil. Linoleic acid is essential for the nutrition of some animals and used as an emollient and thickening agent in cosmetics. There is some research showing it to be effective in cell regulation and skin-barrier repair, as well as an antioxidant and an anti-inflammatory. See also “fatty acid”.

lipid
Wide range of ingredients found in plants, animals and human skin that are soluble in alcohol and other solvents, but not in water. Includes fatty acids, fats, waxes, fixed oils, phosphatides, cerebrosides, and sometimes steroids and carotenoids. Carbohydrates, proteins and lipids are the main constituents of cells. In skin care products, lipids are emollients and thickening agents with a moisturizing and cream action. Lipids are a major constituent of all cell membranes. We lose lipids as we age, which is why skin becomes less supple. Lipids contain carbon, hydrogen and oxygen, but have far less oxygen proportionally than carbohydrates.

lipophilic
Having an affinity for lipids.

lipoprotein
Any of the lipid-protein complexes in which lipids are transported in the blood.

liposomes
Liposomes are microscopic lipid sacs from natural or synthetic sources that are widely used as a way to deliver other ingredients into the skin. When the liposomes “break apart”, the ingredients such as moisturizers, are released. Microscopic spheres are manufactured from natural or synthetic fatty substances that include phospholipids “components of cell membranes”. Phospholipids can trap any substance that will dissolve in water or oil.

LiquaPar OptimaÒ
This is a broad spectrum preservative used in a wide range of cosmetic products including creams, lotions, ointments, exfoliants, lipsticks, liquid and cream makeup, eyeliners, mascaras, and more. LiquaPar is perfect for products including salt scrubs, toners, lotions, creams, shampoos and liquid soaps. It is also non-volatile, remains fully stable over a wide pH and temperature range, is non-irritating to the skin, eyes, and mucous membranes, is devoid of skin sensitizing effects, is biodegradable, and presents no pollution hazard. LPO is fully compatible with plant extract products and is effective as an antimicrobial preservative for aqueous herbal extracts and for cosmetic and pharmaceutical preparations containing plant products. Owing to its many advantages, LPO is suitable for the preservation of topical pharmaceuticals and cosmetic and toiletry products of all types. Its powerful microbiocidal activity in most systems makes LPO effective in those products, which have been found especially difficult to preserve in the past “shampoos, lotions, creams, and protein-rich systems.” For preservative applications, LPO should be evaluated at concentrations of 0.5-1% depending on the conditions. ISP recommends a use level of no greater than 1%. Every new or modified formula should be challenge tested to ensure adequate preservation. Products containing LiquaPar Optima should be labeled as: Phenoxyethanol, Methylparaben, Isopropylparaben, Isobutylparaben, Butylparaben

liquid crystal cholesteric esters
Micro-encapsulated strands of cholesterol lipids for skin repair and moisturizing. Highly absorptive crystals carry active ingredients into the deeper layers of the epidermis.

lithia “lithium oxide”
A vigorous flux often used as a partial replacement for soda and potash. A basic oxide “alkali”.

lotion
Lotion is an emulsion of oil in water “o/w”. Lotion formulations can contain up to or more than 80% water.

lubricant
An oil or oil rich crème or lotion designed to lubricate the skin and slow moisture loss.

luffa “loofah”
The fruit of a long vining plant, similar to a cucumber plant. Once dried and washed of rind and seeds, it becomes a pleasant and effective body scrub. Helps to stimulate circulation as well as exfoliate dead skin cells.

lye
The common name for sodium hydroxide, NaOH, and caustic soda. Lye is a main ingredient in cold process or hot process soapmaking.

lysine
An essential amino acid that is an important constituent of various proteins such as collagen, which makes up the major part of connective tissues in the skin. A deficiency in lysine may result in hair loss.