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.
[1] A blowing agent is a gas that forms the gaseous part of the foam.
Sodium laureth sulfate, or sodium lauryl ether sulfate (SLES), is a detergent and surfactant found in many personal care products (soaps, shampoos, toothpastes, etc.).
Cocamide foaming agents include the nonionic cocamide DEA[3] and cocamidopropylamine oxide,[4] and the zwitterionic cocamidopropyl betaine and cocamidopropyl hydroxysultaine.
Blowing agents that produce gas via chemical reactions include baking powder, azodicarbonamide, titanium hydride, and isocyanates (when they react with water).