Annex 3 - Document and record storage facilities

T/AST/033 - Issue 2

A3.1 General

A3.1.1 All quality documents and records should be securely stored and maintained in such a way that they are readily retrievable in facilities that provide a suitable environment to minimise deterioration or damage and to prevent loss.

A3.1.2 The type of storage facilities required depends on factors such as the records media, environmental conditions (including insect or fungal infestation), safety significance (duplication of copies in diverse locations), duration of retention, security, and both active and inactive records.

A3.1.3 Records should be retained in facilities appropriate to the media. Care should be taken to ensure that record media requiring different storage environments are not stored in the same area. In particular, cellulose nitrate film should be stored in a separate facility.

A3.1.4 Unsuitable environments can cause more damage to records than any other single factor. A dry or polluted atmosphere may lead to embrittlement of documents; dampness and poor ventilation may cause the growth of mould; excess heat may accelerate chemical damage. All three conditions can lead to irreparable damage to records. Careful control and observation of temperature, humidity and ventilation within the records facility is therefore essential. In general, low temperatures with adequate air movement are preferable.

A3.1.5 Fire precautions, including limitations on the distance to travel to reach means of escape and the physical dimensions of the storage facility, are the subject of national legislation and local by-laws. The fire precautions adopted, however, should be designed to protect the contents and structure of the facility from damage caused by fire fighting operations, as well as to ensure the safety of staff and limit the fire to its source. The possibility of fires or explosions in adjacent facilities and the proposed type of fire fighting chemicals to be employed to counter such events should be taken into account when the facility is chosen.

A3.1.6 Loose material should not be permitted and smoking should be prohibited at all times in the storage facility.

A3.1.7 Precautions should be taken during the storage and handling of records to avoid finger marks, dust or scratching on microfilm records (by the provision of suitable hand covering), unnecessary bending or cracking of paper (by the suitable positioning on adequately designed shelving) and failure of components due to static discharge (by the provision of static handling precautions).

A3.1.8 Records entering the record archive facility should be registered. To protect the integrity of the records, the facility should be secure, and wherever possible copies of archived records should be used for reference purposes rather than permitting the removal of the master record.

A3.2 Microfilm storage facilities for up to ten years

A3.2.1 The following storage conditions are considered suitable for the storage of microfilm records for a time not longer than that sufficient for general business purposes. Such a time might be ten years, but could vary depending on specific conditions.

Relative humidity and temperature requirements for the storage of microfilm

A3.2.2 The relative humidity of the storage facility should not exceed 60% and the temperature should not rise above 25°C. Rapid changes of humidity and temperature should be avoided.

Protection of microfilms against fire and water

A3.2.3 Microfilms using safety film are difficult to ignite and combustion speed is low. To provide effective protection of microfilms against fire, as much attention should be paid to the presence of steam as to high temperatures. The protection available in a given room should take into consideration conditions special to that room and also the following general conditions.

A3.2.4 Microfilm stored at 40% relative humidity can withstand a dry heat of 120°C for a time of 24 hr without appreciable loss of legibility and printability. At a dry heat of 150°C some distortion may take place after 6 hr but individual microfilms of texts or figures are still printable. The action of dry heat of 180°C for at least 6 hr causes deformation of microfilms and reproduction generally becomes impossible.

A3.2.5 In the presence of water vapour, temperatures of 90–110°C produce serious distortions and cause adhesion of coils or surfaces in contact; prolonged action or condensation will make the emulsion melt. Fireproof cabinets and safes thermally insulated by water vapour production are therefore not suitable for storing microcopies unless they have an inner moisture-proof chamber or the films are placed inside suitably sealed airtight containers. To obtain complete protection from fire, safes or cabinets should be placed in premises which are themselves fireproof. Microfilms should be protected from the action of water resulting from leaks, fire sprinklers or flooding, by being stored above basement levels on shelves at least 150 mm from the ground. If films are immersed in water, allowing them to dry, even partially, will cause the layers to stick together. The films should be placed in water filled containers until they can be washed and dried properly.

Chemical contamination

A3.2.6 Various noxious emanations can cause slow deterioration and a gradual fading of the image on film. Danger is presented by peroxides which may originate from bleaching agents, glues, varnishes and other products used in manufacturing storage cabinets for film containers. Hydrogen sulphide, ozone, sulphur dioxide, sulphur trioxide, ammonia and oxides of nitrogen are the most common, but not the only, atmospheric gases which harm film. Such fumes should be eliminated or an alternative store found.

A3.2.7 Chemical products in the immediate vicinity of the films may also cause the presence of other impurities in the atmosphere. If dust and liquid particles suspended in the air are deposited on the microfilm they may impair its legibility and cause permanent scratching. Microcopies on silver image film should be kept neither with other photographic records which do not conform to these recommendations, nor with those films explicitly excluded, such as microfilm on a nitrate film base. Cross contamination between microcopies can occur by the transfer of free thiosulphate to sodium (or ammonium) thiosulphate free film if they are stored with the emulsion sides in contact. Radiographs and other photographic media should be stored in chemically benign envelopes. Multiple films stored in envelopes should be separated by benign sleeves or separators.

A3.3 Additional recommendations for archival of microfilms in excess of ten years

Air purification

A3.3.1 Air should be filtered to remove dust, purified of noxious gases and circulated by means of forced draught.

Relative humidity

A3.3.2 If sealed airtight containers are not used, the air in the archival storage facility should be conditioned to maintain the relative humidity at a level between 20 and 40%. If air conditioning is used, dehumidifiers using calcium chloride or other chemical desiccants should not be used. An electrical dehumidifier is recommended. If dehumidifiers are used, they should be of a type that does not produce rapid changes in the relative humidity.

Temperature of the archival premises

A3.3.3 The temperature in the archival storage area should be maintained between 15 and 25°C, but preferably should not exceed 20°C. If film which has been stored at a low temperature is handled in a room where the temperature or relative humidity is comparatively high, condensation will occur on the cold film surfaces. In these circumstances the film should not be removed from its closed container or the place where it is stored until the storage temperature has been brought up to the approximate temperature of the room where the film is to be handled.

Containers

A3.3.4 The following two types of container are recommended:

(1) The closed non-airtight container.

(2) The sealed airtight container.

A3.3.5 If the recommendations for relative humidity and temperature of the archives are observed, containers for storage of microfilm can be of the closed non-airtight type. Sealed airtight containers should be used if there are no other means of protection against the danger of an ambient atmosphere of which the relative humidity or temperature goes beyond the limits recommended in this annex or which contains chemical impurities or dust. The containers used should be made from materials meeting the requirements below. These containers may be placed in boxes of paper or board, but such boxes should not be used alone.

General precautions for the long term protection of microfilm records

A3.3.6 The use of non-corroding materials for containers is recommended but whatever the materials used for the containers, their corrosion resistance coating and their airtight seals should not melt, ignite, decompose, develop fumes, distort or be subject to excessive dimensional changes when subjected to a temperature of 150°C for 4 hr.

A3.3.7 Care should be taken to avoid the deterioration or damage which may result from the rust, rubber joints, rubber bands and gum on certain types of envelope, and of lignin and other peroxide forming substances contained in certain wooden materials.

A3.3.8 Microcopies stored in roll form may be mounted either on reels or on cores. Rolls more than 30 mm long wound on cores should be laid flat unless the core itself is carried on a horizontal spindle which prevents the lower part of the film from supporting the load of the core and its contents.

A3.4 Additional precautions for sealed airtight film containers

Fire

A3.4.1 The container should be of a type which will prevent steam reaching the film in the event of fire. Containers with a high resistance to corrosion are recommended. The container and its airtight seal should withstand an excess pressure inside the container of 70 kPa without rupture of the seal or other injurious effects.

Relative humidity

A3.4.2 The relative humidity inside a sealed airtight container should be within 20 to 40% at the storage temperature. Relative humidity exceeding 60% encourages the formation of mould which, in time, can completely destroy the image. Below 15% the film tends to curl and become more brittle as the relative humidity decreases.

A3.5 Storage facilities for paper

Relative humidity and temperature requirements for the storage of paper

A3.5.1 The relative humidity of the storage facility for paper should be within the range 55 to 65% and the temperature should be within the range 13 to 18°C. However, if the paper is in bound volumes and is little used, it may be stored at a relative humidity of 40%.

A3.6 Storage facilities for magnetic tape or disc — optical laser disc — hardware — electronic firmware

A3.6.1 Magnetic tapes or discs, optical laser discs, electronic firmware and general hardware records should be archived in accordance with the manufacturer’s requirements or the component media. The retention requirements should be consistent with the life expectancy of the media and should provide for rejuvenation and backup.