Preservation of Library Documents

Senior Librarian,
Aravind Eye Care System.

Library materials Consist of paper based reading materials in the form of manuscripts, books, periodicals, paintings, drawings, charts, maps etc and digital Storage media. The basic materials and constituents of the physical entity of these library materials are mostly organic in nature, which are susceptible to natural decay and deterioration. In books, apart from paper the other materials used are board, cloth, leather, thread, ink, adhesive etc. All these materials are nutritious for some living organisms. So the library materials need protection from factors of Deterioration.

Causes of Corrosion of Library Materials
All formats of library materials possess inherent limitations in their chemical or physical structures. In addition, a number of external factors such as careless handling of materials, theft, vandalism, light, pests, pollutants, extreme variations in temperature and relative humidity, water, and fire can greatly accelerate the normal process of deterioration

  1. Climatic and Environmental factor

  2. 1.1.Temperature
    In general, the higher the temperature the more rapidly materials will deteriorate, and the lower the temperature the longer materials will last.

    Exposure to intense light causes fading (especially of inks and colors), darkening and yellowing (especially of paper containing wood and lignin), and the weakening of fibers. Both sunlight and artificial light (especially fluorescent) are sources of ultraviolet, the most harmful of the light wavelengths. However, all direct light is damaging to some degree. Materials are at their most vulnerable when exposed on long-term display or when stored under strong, constant light, for example, in front of a window.

    1.3.Pollution of Air
    Pollutants are generally in the form of gasses and particulates. While most pollution enters a building from outside, pollution can also be caused by construction materials, paints, untreated wood, particleboard, and plastics, which emit gases that are harmful to paper. These include sulphur dioxide, carbon monoxide, formaldehyde, and a wide variety of industrial gases. Pollution also occurs in the form of tiny solids, or particulates, such as grit, dust, and smoke. Small dust particles are especially damaging
  1. Biological Factors

  2. 2.1.Mold
    One of the most common Problems in libraries and archives in humid is mold. Mold is general term given to variety of fungi. Moisture provides the necessary conditions for mold germination. The mold is usually the result of high humidity and poor air circulation. Mold can grow on any moist surface, including materials such as paper, leather, and book coverings, causing disfiguring, and multicolored stains and greatly reducing the material's strength. Mold damage to non-book materials.

    Insects pose a serious threat to collections of all types. The environment that is the most damaging to collectionshigh humidity, poor air circulation, poor housekeepingis most beneficial to insects. Some Harmful insects are Cockroaches Termites Silverfish, and Rodents.
  1. Chemical Factors

  2. In the manufacturing of paper sometimes fibers are used with low cellulose contents and some chemical compounds like alum, rosin etc. are used for sizing of paper which cause acidic effect and facilitate chemical deterioration of the paper with the passage of time.

    Ozone acts as a powerful destroyer of organic materials. It makes the colours of fabric book covers fade and the book binding materials such as leather, gelatin, glue and paste are also susceptible to deterioration by ozone in humid atmosphere.

  2. Apart from physical and chemical factors, a serious cause of deterioration often is the casual attitude of the library staff as well as the users of the library towards books as physical objects. The standard of care and handling of books by their custodians and users is often pretty low. Improper storage, faulty repairment, rough handling, deliberate abuse, folding the fore-edges of pages as a mark of reading, marking by ball pen, mutilation, vandalism are all examples of deterioration of books by human beings.

  2. Natural disasters like structural fires, serious medical emergencies, or releases of dangerous fumes and gases No library is exempted to the devastations that can occur as a result of natural or man made disasters.
Preventive Measures
The processes of preservation, conservation and restoration are applied to safe quard the library materials from further decay and deterioration. Preservation is the process in which all actions are taken to check and retard deterioration where as conservation includes proper diagnosis of the decayed material, timely curative treatment and appropriate prevention from further decay.
  1. Control of Environmental Factor

  2. Selection site and the soil on which it will be constructed of the Library building is very important and also or library It is very important to choose the best architectural design for the library having cross ventilation facilities for free air circulation within the building. If there is a need to use wooden materials, the wood selected should be well seasoned and must be treated chemically to avoid insects.

    Sunlight should be prevented from falling directly on papers because the sun is a great emitter of ultraviolet rays. The windows must be provided with colored curtains, which will prevent falling of direct light as well as absorb ultraviolet rays.

    As high humidity and high temperature are more hazardous for library materials it is advisable to maintain ideal room temperature (200-250c) and relative humidity of (RH45- 55%) for preservation of documents.

    Air conditioning of the stack area round the clock is an ideal example of maintaining optimum temperature & humidity for the storage of documents. But it is practically not possible for all the libraries to afford for air conditioning for 24 hours. So it is useful to adopt local control measures like use of humidifiers in dry climate to increase required level of moisture content and dehumidifiers to remove moisture in wet seasons.
    During the summer months when the temperature is high the windows should be kept closed. If the windows are to be kept open wet curtain should be used. High speed air circulators also be used for free air circulation.

  1. Control of Biological Factor

  2. Pest Control
    Various methods have been used to eradicate pests, with differing degree of success. These include ethylene oxide (ETO), methyl bromide, formaldehyde, and, more recently, gamma radiation. More recently, tests Gamma radiation have shown the advantage of both cold and heat to kill harmful insects. Temperature manipulation is preferred to toxic chemicals.

    Killing insects
    A Freezer set at or below -20 C (-3 F) can be used to kill insects, which should be exposed for Three to four days. Books should be placed in plastic bags and, on removal from the freezer, conditioned under a constant air current from a fan. Freezing is best for occasional infestations, not for routine treatment.

    A simple chest freezer can be used. Heat can also be used to kill insects in infested materials. Temperatures of 50C (120F) will dry out insect bodies. In tropical areas, infested books can be placed in a metal container wrapped in black plastic and left in direct sunlight for a few hours.

    Good housekeeping
    Good house Keeping in a library building is important. Accumulated dust and dirt can stain books and speed up deterioration. Floors can be cleaned by wet dusters. As accumulation of dust and dirt accelerate the physical damage of books, a cleaning schedule should be made considering the sequence of operations following daily and weekly routines. Specific instructions should be given to clean remote corners of the book shelves, behind cabinets, under desks, chairs, and all surfaces accumulating dust. The best way is to use a vacuum cleaner because it sucks the dust and can not resettle on the surfaces. Policies limiting or banning food and drink in libraries help to minimize this problem. Remember that staff act as role models for the library users.
  1. Control of Human Factors

  2. 3.1.Handling Care Books and other Reading Materials
    Most damage occurs to library and archive materials when they are being handled. Careful handling of library materials by all library staff will help preserve them and will also encourage users to handle these materials correctly.
    • Wet fingers should not be used to turn pages.
    • Rare or tightly bound books should be laid open on a book support available in the Reading Room.
    • Never lean on books or documents for a writing surface.
    • Do not fold the corners of pages or use printed, colored or adhesive paper, such as post-it" self-adhesive notes.
    • Do not allow oversize materials to hang over the edge of work surfaces.
    • Do not repair important library materials with household glue, rubber cement.
    • Appropriate book trucks should be used for moving books form place to place. It reduce the chance of dropping books and breaking the bindings
    • When books are opened for reformatting by microfilm, photocopy, or digital imaging, most importantly, don't press down on the spine of books and take extra care with large and heavy books. There are some types of materials which are so fragile they should not be photocopied at all.

    3.2.Preventions care of Magnetic Media
    Magnetic media, such as floppy disks and audio/video tapes, is a sensitive medium. Direct finger contact on tape or disk will cause contamination and, possibly, loss of data. Skin oils attract dust and lint.

    Never place floppy disks or other magnetic media close to a magnet or other magnetic sources. Televisions, computer monitors, and telephones all produce magnetic fields. Don't use their surfaces as storage areas for recorded magnetic media. Computer systems staff can supply more information about the care of computers and computer-related products.

    Protective storage is important for all magnetic media, from office floppy disks to home videotapes. Small particles of dust, smoke, and air pollution can cause data errors and image loss.

    Store computer and videotapes vertically. Check them annually for deterioration. Rewind tapes every few years to redistribute tape stress and avoid print-through if items are in long-term storage.

    A clean, stable environment is important for all library materials, but is particularly critical for non-print media. Keep temperatures and relative humidity controlled at the level that is best for the medium being stored. Microfilm, microfiche, and other photographic products should be stored at 30% RH, while magnetic media can tolerate up to 60% RH as long as it remains constant. Temperatures should be maintained at 65.0-70.0F. if materials are stored in a public space, lower if strictly a storage area.
  1. Prevention of Disasters

  2. Disasters are generally unexpected events with destructive consequences to a Collection. Therefore it is vital for any library to take every possible precaution to prevent the occurrence of an unavoidable disaster.

    Fire alarms and prevention:

    Obviously, fire in a library or archives can be disastrous, so an alarm system that will notify personnel that a fire has started must be in place.If possible, an automatic sprinkler system should protect the collection and surrounding structure, but in any case extinguishers should be readily available.

    Auditing of a facility includes checking the condition of electrical wiring, reducing flammable rubbish accumulation, ensuring that other combustibles such as paraffin or petrol are away from the books.
Prevention and preservation Plays a key role in preserving the documentary heritage for Library. Preventive conservation should be practiced to keep the documents in healthy, good and usable condition.