CHEMGUARD High-Expansion Foam Concentrates are flexible firefighting agents used in fighting Class A, Class B, and LNG fires both indoors and outdoors. Typically proportioned at 2%, CHEMGUARD high-expansion foam concentrates are generally used in contained areas, such as aircraft hangars, mines, and shipboard compartments, where volume fire control is required. CHEMGUARD high-expansion foam concentrates are suitable for use with low-, medium-, and high-expansion foam generating equipment.