Foaming agent

A foaming agent is a material that facilitates formation of foam such as a surfactant or a blowing agent. A surfactant, when present in small amounts, reduces surface tension of a liquid (reduces the work needed to create the foam) or increases its colloidal stability by inhibiting coalescence of bubbles. A blowing agent is a gas that forms the gaseous part of the foam.

Surfactants

Sodium laureth sulfate, or sodium lauryl ether sulfate (SLES), is a detergent and surfactant found in many personal care products (soaps, shampoos, toothpastes, etc.). It is an inexpensive and effective foamer. Sodium lauryl sulfate (also known as sodium dodecyl sulfate or SDS) and ammonium lauryl sulfate (ALS) are commonly used alternatives to SLES in consumer products.

Blowing agents

There are two main types of blowing agents: gases at the temperature that the foam is formed, and gasses generated by chemical reaction. Carbon dioxide, pentane, and chlorofluorocarbons are examples of the former. Blowing agents that produce gas via chemical reactions include baking powder, azodicarbonamide, titanium hydride, and isocyanates (when they react with water).