As from January 2001, gaseous fire extinguishing systems have been controlled by International Standard No 14520(1). This covers all the extinguishing gases introduced to supersede halon (e.g. argonite, inergen, FM200). It was published following the European Union decision(2) requiring halon systems to be decommissioned by the end of 2003. Under this Standard, it is a requirement that an enclosure integrity test is conducted both upon system installation and annually thereafter as part of the routine maintenance schedule. This is to ensure that an extinguishing concentration is held for a sufficient time to prevent reignition in the event of a fire.

Studies reveal that the predominant cause of failure of gaseous extinguishing systems is inadequate room sealing. It is also found that rooms get leakier with time, usually due to changes in construction, cabling or services. It is therefore important to ensure that good room integrity is established and maintained, particularly bearing in mind the potential consequences of system failure. Annual integrity inspection and testing are required by the BFPSA(3) and are now routine practice at most major commercial institutions. The benefits of this are widely recognised by insurers and regulatory authorities, who frequently require such testing(4). Annual integrity test requirements are also a requirement for U.S. designed systems under NFPA Specification 2001(5).