Glossary Terms – E



A liquid used to extract one material from another.


A mixture of two liquids that normally cannot be mixed, in which one liquid is dispersed in the other liquid as very fine droplets. Emulsifying agents are often used to help form the emulsion and stabilizing agents are used to keep the resulting emulsion from separating. The most common emulsions are oil-in-water emulsions (where oil droplets are dispersed in water) and water-in-oil emulsions (where water droplets are dispersed in oil).

Emulsion Stabilizer

Ingredients that help to keep an emulsion from separating into its oil and liquid components.


A protein found in animal and plant cells that help to initiate or to accelerate specific chemical reactions.


Epidemiology is the branch of medicine that deals with the study of the causes, distribution, and control of disease in populations. Epidemiology studies the distribution of diseases in populations and the factors that might influence the occurrence of disease. Typically, epidemiology will explore human exposures or life styles and attempt to determine if there is a correlation between the exposure and a particular health affect.

Epilating Agent

Waxes or other substances that are heated, applied to the skin, and stripped off quickly to remove unwanted hair.

Essential Oil

A concentrated liquid containing volatile aroma compounds from plants.


An organic compound formed by the reaction of an acid with an alcohol.


An organic compound that contains an oxygen atom bound to two hydrocarbon groups. An ether compound is often represented by R-O-R’.


Ingredients that help to remove dead skin cells from the skin surface.

External Analgesic

Ingredients that are applied to the skin to relieve pain. In the United States, external analgesics are regulated as Over-The-Counter (OTC) drug ingredients.


The mixture of substances drawn out of a material by solution, heat, or another physical or chemical process.