You'll often see these terms when reading about personal care products and ingredients. Here are some helpful definitions.

Antioxidants - Substances that counter the destructive effects of free radicals in the body, which are a major cause of disease and aging. Antioxidants protect tissue against cellular damage by stabilizing free oxygen molecules. Often used in natural preservative systems to prevent oxidation of fats and oils. Some natural antioxidants are vitamins A, C and E, alpha lipoic acid and green tea.

Detergents - Cleansing agents that are chemically different from soaps, but resemble them in the ability to emulsify oils and hold dirt in suspension. Detergents can vary widely in composition. Though some can be plant-based, most are processed with petroleum derivatives or are synthetic. Examples: sodium lauryl/laureth sulfate, cocamide DEA, cocamidopropyl betaine.

Emollients - Oils and other ingredients that soften and smooth the skin and reduce dryness, roughness and irritation. In hair care products, they restore lost moisture to hair fibre, contributing to shine and strength. Examples: coconut fatty alcohols, essential fatty acids, shea butter, jojoba oil.

Emulsifiers - Substances used to help oil and water bind together and stay in suspension. Examples: lecithin, carrageenan.

Exfoliants - Used in masks, scrubs and cleansing lotions, exfoliants encourage skin cell regeneration by removing dead skin cells, making way for new cells underneath. Manual exfoliants such as ground nuts, meals and jojoba wax spheres gently slough off dead skin cells, while fruit acid exfoliants dissolve the cellular glue that holds skin cells together to reveal new, fresh cells. Enzymatic exfoliants such as papaya digest dead skin cells and offer the mildest form of exfoliation.

Humectants - Promote water retention in hair and skin care products by attracting and binding water to themselves. Examples: vegetable glycerin, sorbitol, honey, mucopolysaccharides.

Hydrators - Supply water to the hair and skin. Plant liquids are the best source of beneficial hydrating agents. Examples: aloe vera, orange pith juice, vegetable glycerin, deionised water.

Saponins (Glycosides) - Substances found in nature that foam readily in water, used as foam boosters, emulsifiers and mild cleansing agents in natural shampoos. Examples: quillaya, yucca, soapwort. Soaping agents with properties similar to plant glycosides can be made from coconut fatty alcohols and cornstarch glucose. Example: coconut/corn oil soap.

Sequestrants - Chelating agents that act by binding to and removing metal ions (such as calcium, magnesium and iron) and non-metal ions (such as chlorine and salt) from hard water, causing hair to be cleansed and rinsed more thoroughly. Sequestrants also help minimize discoloration of natural and colour-treated hair that might normally be altered by pool and salt water or excessive perspiration. Examples: corn syrup, citric acid, kelp extract, alginate.

Soap - A natural cleansing agent (surfactant) with the ability to emulsify oils and hold dirt in suspension. Bar soaps are made from the combination of fats, oils and/or fatty acids and sodium salts (sodium hydroxide, an alkali) dissolved in water. In liquid soap, potassium salts (potassium hydroxide) are utilized. While sodium and potassium salts can be harsh and drying, in a properly balanced formula, sodium hydroxide and potassium hydroxide cease to exist as separate entities when they combine with the oils to form soap, leaving no potential for skin irritation.

Surfactants - Surface active agents responsible for wetting, dispersion and emulsification. Wetting enhances the spreading and penetrating ability of a liquid, which in turn improves the cleaning ability of water. There are three basic types of surfactants commonly used in shampoo formulas: detergents, soaps and glycosides.

Tonics - Herbal extracts that soothe, clarify, stimulate or otherwise improve the condition of the skin, hair and scalp. These are typically extracted in vegetable glycerin, water or natural grain alcohol, or added as essential oils. Examples: horsetail, nettle, ginseng, camomile.

Volumizers - Substances that bind to and thicken hair fibre to increase fullness. Examples: soy protein, almond protein, wheat protein, panthenol, herbal gums.

* References taken directly from Aubrey Organics