1. Deterioration of Documents

2. DEFINITION
A change of original state of any material through the interaction between the object and factors of destruction.

3. Relating to Documents:
Any form of degradation or reduction in the quality or usable life of a document resulting from its inherent qualities or interaction with destructive elements in the environment.

4. Process of Document Deterioration
Most documents are made of organic materials which undergo natural ageing. Natural ageing is a slow but inevitable process.

5. Natural ageing cannot be stopped
Natural ageing cannot be stopped. The rate of natural ageing can however be slowed down.

6. Rate of Document Deterioration.
Depends On:
Chemical Stability of the document
Environment
Storage Conditions
Handling Procedures

7. The environmental factors/elements that can influence the rate of document deterioration include:
Temperature
Humidity
Light (Radiant Energy)
Pollution

8. Biological Agents Disasters Fungi Insects Rodents Human beings
Environmental factors continued…
Biological Agents
Fungi
Insects
Rodents
Human beings
Disasters

9. On their own, these factors can be dangerous to documents.
But acting jointly, they can be deadly, resulting in rapid degradation of documents, ultimately resulting in total loss.

10. Types of Deterioration.
Chemical Deterioration
Biological Deterioration
Physical Deterioration
Deterioration through Disasters

11. Chemical Deterioration
Chemical deterioration is document degradation which emanates from chemical activities ( reactions) which results in the introduction of various forms of acidic compounds into the fabric of the document – particularly paper documents.

12. Chemical Deterioration can result mainly from the following elements
Temperature
Humidity
Light
Pollution

13. Temperature
Temperature is the degree of hotness or coldness of a body.

14. Temperature has impact on documentary materials in the following ways:
At high temperatures, chemical reactions are speeded up ( For every 180 F increase in temperature, chemical activity in most substances double).
Acid is introduced at a faster rate, hydrolysis takes place and documents get decomposed – they become brittle, craky and easily break at a touch.

15. 2. Estimated that the useful life of a paper document is reduced by ½ (Half) with every 100 C increase in temperature.
3. At high temperature, film documents buckle at the edges, plastic base documents warp. 4. At high temperature, desiccation takes place.

16. 5. Fluctuating temperatures (cycling) are worst for documents
5. Fluctuating temperatures (cycling) are worst for documents. They result in expansion and contraction – documents disintegrate easily.

17. Recommended Temperatures:
Paper Documents – 200C ± 20C
Film and Electronic Documents – 180C ± 20c
These must be kept as close to constant as possible.

18. Control of Temperature
Air Conditioning
Good Ventilation

19. Monitoring Daily readings must be taken using a thermometer.
Readings must be recorded and consolidated to determine trends.

20. Humidity
Definition: The amount of moisture in a given volume of air at a given temperature.

21. Types.
Absolute Humidity
Ambient Humidity
Relative Humidity

22. Effects Most chemical reactions are water (moisture) dependent.
High Humidity and high temperature speed up chemical reaction.
Low humidity results in the desiccation of paper.

23. A combination of high temperature and humidity encourage mold or mildew – fungus growth (65% RH+200C)
High humidity and high temperature levels increase the likelihood of insect infestation.
Under excessive humidity, water soluble inks smudge, feather or run.

24. Coated or glossy paper stick together.
Normal paper – photocopy or printing paper became damp/soggy and adhere to each other.
Film based documents get stuck to each other.

25. Fluctuations are even more dangerous – they cause internal stress and instability of the fibres of paper due to the contraction and expansion, thus breaking the bond to bond holding of the paper.

26. Controlling No easy solution.
Because of the varied range of documentary materials which respond differently to humidity and temperature.
Ideally, separate storage area should be used. This is not always the case because of the cost involved.

27. Theoretically the lower the humidity and temperature, the better
Theoretically the lower the humidity and temperature, the better. But this is expensive to maintain particularly so since humidity levels increase with drops in temperature.

28. Ideal Control
Control both temperature and humidity through air conditioning for 24hrs a day. Paper Doc. – 45% ±2% and 200C ± 2) Film + Digital Docs. -35% ± 2% (180C ± 2)

29. In the absence of air-conditioning facilities;
Use Humidifiers and Dehumidifiers (Electronic/ Chemical).
Windows should be widely opened to allow free circulation of air.

30. Heavy cotton curtains should be used – they absorb excess humidity at peaks and exude moisture at low times to ensure equilibrium.
Wooden furniture could be used to absorb excess moisture.

31. Monitoring Measuring Instruments; Hygrometre Hygrothermograph
Humidity Indicator Card
Data Logger