What is the name of a liquid such as foam concentrates and emulsifiers that is intended to be added to water?

The term that best describes a liquid such as foam concentrates and emulsifiers that is intended to be added to water is "additive." Additives are substances added to another substance to enhance its properties or performance. In the context of firefighting and fire suppression, foam concentrates serve as additives that enhance the effectiveness of water in extinguishing fires, particularly those involving flammable liquids.

Foam concentrates, for instance, must be mixed with water to create a blanket of foam that smothers fire, preventing its re-ignition and cooling the fuel. The proper formulation and mixing of the additive with water are crucial for achieving the desired fire suppression effectiveness.

While the other terms have their own definitions, they do not specifically convey the sense of a substance added to another for improving or altering its performance. An adjuvant typically refers to a substance that enhances or modifies the action of another substance, often used in agriculture or pest control but does not directly imply the mixing with water for firefighting. Solvent is a term used for a substance that dissolves a solute, creating a solution, but doesn’t necessarily imply enhancement of another medium like water in the context of firefighting. An emulsion refers to a mixture of two immiscible liquids