Fixed firefighting systems - Foam systems - Part 2: Design, construction and maintenance

This document specifies the requirements and describes the methods for design, installation, testing and maintenance of low, medium, and high expansion foam fire extinguishing systems. Foam systems may be used to suppress the release of toxic vapours but this application is outside the scope of this document. This document provides guidance for the design of various foam systems available to persons with knowledge and experience in determining the selection of foam fire extinguishing systems which will be effective in protecting specific hazard configurations. For the application of this standard, a risk assessment by a qualified and experienced person should be performed for both new and existing systems, however the risk assessment is outside the scope of this document. This document does not cover a risk analysis carried out by a competent person. Nothing in this document is intended to restrict new technologies or alternative arrangements, provided that the level of foam system performance prescribed in this standard is not lowered, and supported by documented evidence/test reports. All foam systems are generally unsuitable for the following: - chemicals, such as cellulose nitrate, that release sufficient oxygen or other oxidizing agents which can sustain combustion; - energized unenclosed electrical equipment; - metals such as sodium, potassium and sodium-potassium alloys which are reactive to water; - hazardous, water-reactive materials such as triethyl-aluminium and phosphorous pentoxide; - combustible metals such as aluminium and magnesium.