Disaster preparedness includes all measures to prevent, or at least minimize, the negative effects of unpreventable incidents of all kind, be they of natural origin, such as earthquakes and extreme weather conditions (which seem to be becoming more common in recent years), or man-made, like civil unrest, warfare, and others. The basic elements of disaster preparedness start with factors such as the choice of site for new archive buildings. A systematic search for any intrinsic dangers in existing archive buildings and their neighbourhoods should also be undertaken. Detailed plans to react appropriately in the case of unpreventable disasters will need to be prepared. These should have the protection of staff and visitors, as well as the survival of the collection, as the foremost principles to be considered.
A detailed discussion of disaster preparedness is beyond the scope of this publication. Environmental influences and specific preventive measures have been discussed in the respective parts of chapter 3. However, because of particular risks of fire and water to audiovisual carriers, these two aspects are covered here.28 Finally, because of the absolute dependence on electric power, the necessity of an uninterrupted power supply in the case of disaster is underlined.
28. For general aspects of disaster preparedness, see bibliography.
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.
Apart from keeping humidity low (3.1), special attention must be given to the prevention of water influx, which may come from a variety of sources. Storage areas should, therefore, be protected against water influx from all sides. This is most easily achieved if the store is located in an elevated position above the ground floor. A waterproof ceiling will prevent influx of water caused by plumbing leakages, heavy rainfall and water from fire extinguishing in upper floors. There should be no connection to the sewerage system, which, in case of floods, would be a path for influx. If an underground location cannot be avoided, careful consideration must be given to the prevention of influxes resulting from inundations, particularly in tropical areas, where storms can produce unexpectedly high amounts of water in a very short time. The installation of automated pumps may be advisable. In any case, materials should be stored some distance above the floor to help safeguard them for a period in the case of influx and give time for preventive actions to become effective. (For drying and cleaning flooded materials see 3.1.2.)
The operation of audiovisual archives depends on the availability of electric power. An uninterrupted power supply is essential for maintaining a digital repository and is also an essential for the operation of fire alarms and extinguishing systems. Even in technically highly developed areas, an uninterrupted power supply must always be a part of the respective systems. Additionally, to cope with the individual situations faced by developing countries, independent power supply units that produce sufficient power to keep the archive in operation in the case of frequent or prolonged black outs must be installed.
It should be kept in mind, however, that even in areas with normally reliable public power supplies, fire or unusual natural disasters will probably lead to power supply problems for which preventive measures must be in place. Most important is the provision of battery powered emergency light installations that will permit the safe evacuation of visitors and staff and assist the organisation during rescue measures. Additionally, depending on the necessity to keep equipment in operation, such as automated pumps to keep water out of storage rooms, adequately powerful stand-by generators with auto-starting mechanisms must be in place. These standby systems must be tested periodically.