5.2 Fire
Fire prevention and extinguishing must be given utmost importance. Beyond the safeguarding of invaluable material it must be understood that burning audiovisual carriers produce highly toxic fumes, which are of considerable risk to health. In addition to irreplaceable losses of holdings, complicated and expensive decontamination of premises may be the result of such incidents.
Ideally, the entire building housing an audiovisual collection should be separated into smaller fire divisions or zones of appropriate dimensions and equipped with a fire detection system. The walls, floor, and ceiling of each storage area should be fireproof and equipped with an automated fire extinguishing plant. In the 1970s and 1980s, Halon gas29 was widely used as a fire-extinguishing agent for sensitive cultural materials. This was also recommended by IASA in 1981 (IASA-TC 02). Because of its effect on the depletion of the ozone layer, Halon and other fluorochlorinated hydrocarbon agents were banned in the Protocol of Montreal in 1989. Today, a number of more environmentally friendly Halon replacement gases are available for traditional materials as well as for server rooms of digital archives. These are also recommended for audiovisual materials.
The so called “dry fog” systems, that spray water in a very finely dispersed mist into the vault, are gaining popularity as the cooling effect is of great help with the protection of carriers exposed to heat from a fire, while water damage is very minimal. Such systems can be used for all kinds of archives. They are unsuitable, however, for electrical installations such as digital repositories (servers). Some archives are also starting to use low-oxygen storage, a technology that reduces the oxygen level in the air in the storage area below the point where a fire can be sustained.
Hand-held fire extinguishers should contain CO2. Water, foam, and powder, the most popular agent used in office-type extinguishers, must not be used. While chemically harmless, the removal of the fine dust of powder extinguishers from contaminated audiovisual carriers is extremely time consuming and is sometimes not possible to achieve.
29. Halon and its replacement gases extinguish fires in a concentration that is not dangerous for persons inadvertently trapped in a storage area in the case of flooding. Carbon dioxide (CO2) would be very effective and cheaper, but its use is strongly discouraged, often forbidden by legislation, because of the enormous risk for personnel, particularly in the case of false alarms.
