Paper Archives and the Agents of Deterioration
Introduction
The damage caused to archive materials are known as ‘agents of deterioration’. There are 10 agents of deterioration. These are:
Physical Force
Physical force is also referred to as mechanical damage. It is all about how you handle your objects. Most physical damage to archive materials comes from general use but can also be caused by accidents. Handling causes considerable wear and tear to your archives. Archival materials are easily damaged when handled. Poor handling can cause tears, losses (where whole sections of the image are detached) and scratches.
The greatest risk to your archives, on a day to day basis, is from physical force.
Image shows a selection of documents squashed into a document case. Incorrect storage with unsupported items. Image courtesy of Victoria Stevens
Image shows pages from a document with a large dirty footprint on the reverse of one of the pages. Footprint. Image courtesy of West Yorkshire Archive Service
Fire
Fire is a catastrophic agent of deterioration. Fire can cause:
Partial or complete loss of archive material.
Chemical changes due to combustion reactions.
Physical changes due to heat damage.
Physical and chemical changes from smoke and from the water used to extinguish the fire.
Deposits of soot on objects.
In 2018 the National Museum of Brazil was heavily damaged by fire. Of the 20 million objects it held, only 2000 had been recovered one year later.
Image shows a bundle of documents, tied with string, blackened with soot. ‘Soot damage: Image courtesy of West Yorkshire Archive Service
Image shows a bundle of documents in a pile, marked with soot. Soot damage: Image courtesy of West Yorkshire Archive Service
Water
Water ingress into your archive can be as equally catastrophic as a fire. Water can cause:
Partial and complete loss of media and/or archival material.
Mould.
Pest infestation.
Physical damage such as distortion and deformation of objects, shrinking.
Staining and tidelines.
Objects sticking together.
Water can enter your archive due to natural events such as heavy rain and flooding rivers or from disasters such as an overflowing sink or bursting pipes. Water leaks and floods are the most common causes of water damage, but can also be caused by simply spilling a drink.
Image shows a folder opened to the back covers, showing water damage. Water damage. Image courtesy of Victoria Stevens ACR.
Theft and Vandalism
Theft and vandalism happen. Theft can be opportunistic or premeditated. It can occur when readers, staff and/or volunteers steal archival material or when objects on display are deliberately targeted. Vandalism is the wilful or premeditated infliction of damage to an object. Vandalism can include removal of pages from books and drawing/writing on the archival material. Remember that arson is a form of vandalism; which takes us back to the agent of deterioration: fire.
Image shows an open book with the top left corner of the page folded over. Corners folded. Image courtesy of National Library of Scotland
Chemical
These come from external and internal sources. External includes dust, skin, hair, fibres, soot and pollen which cause dirt, abrasion and can attract insect pests and mould. Chemicals also come from unsuitable storage materials and gases from aerosols, paints, glues and air fresheners. These gases can cause fading and discolouration and make the paper and card supports brittle. Internal or intrinsic factors include the object itself and other factors such as iron gall ink, pins and inclusions. These intrinsic factors can cause acidification, discoloration and staining, and may accelerate the rate of deterioration.
Image shows crinkled and buckled plastic on a black background speckled with white. Degraded acetate negative Image courtesy of Victoria Stevens ACR
Image shows two documents, the one on the right is printed matter (black and white) the one on the left shows the imprint on a cream background from ink transfer of the right hand document. Chemical damage ink transfer. Image courtesy of West Yorkshire Archive Service
Pests
Your archive provides food for moulds and insects such as silverfish and carpet beetles. Archives are at risk from mould, insects, rodents and birds and their droppings. These pests can cause complete loss of the object, discolouration and staining, and can decimate a collection.
Image shows a close up of a document surface where parts are pitted or completely destroyed. Pest damage. Image courtesy of West Yorkshire Archive Service
Image shows a document cover with the word 'Methley' in italic script and pest damage evident at the top of the cover. Pest damage. Image courtesy of West Yorkshire Archive Service
Neglect
Neglect is when on-going care is not taken to protect the archive or where collections care practices are not kept up-to-date. Another form of neglect is dissociation. Dissociation refers to the loss of information associated with an object. Dissociation can cover loss of identification labels, misplacement of parts of an object and lack of descriptive information.
LINK. Good storage practice for archives
Image shows bundles of documents bound with canvas straps sitting on the shelf, the first two bundles are upright, the next two are curving over into a c shape. Incorrect storage: unsupported items. Image courtesy of Victoria Stevens ACR
Image shows a carboard box containing a mixture of glass and paper objects/documents. Incorrect storage: unprotected fragile items stored together. Image courtesy of Victoria Stevens ACR
Incorrect Relative Humidity
Relative humidity (RH) is the measure of what most of us refer to as humidity. It can be too dry (low RH) or too damp (high RH).
When warm air is cooled, the RH increases, leading to problems of damp. The opposite happens when cold air is heated, the RH falls.
A high RH (damp) can cause:
Mould.
Increased pest activity.
Mechanical damage such as warping and distortion of boards, cockling of paper and sticking to glass for framed objects.
Corrosion of metals such as book clasps, paper clips and other metal fasteners.
Chemical deterioration
A low RH (dry) can cause:
Embrittlement of objects.
Mechanical damage such as splits, tears and cracks
Chemical deterioration such as yellowing of paper.
Image shows three folders stacked on top of one another with the covers showing mould. Incorrect RH (high) surface mould. Image courtesy of Victoria Stevens ACR
Image shows a detail of a document with mould on the surface of the cover. Incorrect RH (low) surface mould. Image courtesy of Victoria Stevens ACR
Light
All light is damaging but light with high concentrations of blue and UltraViolet [UV], such as daylight and unfiltered fluorescent light, is the most damaging. Light damage is cumulative and cannot be reversed.
Light causes:
Fading.
Yellowing of papers and boards.
Embrittlement of papers and boards.
Heating of the object, and as such becomes a form of incorrect temperature.
Image shows a book being held so that we can see that the front cover is bright red and the spine has faded to light red. Light damage to book. Image courtesy of National Library of Scotland
Incorrect Temperature
Incorrect temperature falls into three categories:
Too high
Too low
Fluctuating
Temperature controls how fast your archives fall apart. The warmer it is, the faster your archive material will deteriorate.
Temperatures that are too high can also cause:
Softening of waxes, resins and coatings, leading them to become tacky and easily marked when handled, and to absorb dust more easily.
Failure of adhesives.
Increase in the lifecycle of some insect pests.
A temperature which is too low can cause:
Physical damage. Objects can become stiff and brittle, with the result that they are more likely to crack when handled.
Temperature fluctuations can cause:
Condensation.
Physical damage such as cracks, splits and tears.
Loss of media.
LINK. Guidance on Environmental Management.
Sources and Resources
Freely accessible 10 agents of deterioration course https://www.ica.org/en/collection-care-10-agents-of-deterioration-learning-resources
BS 4971: 2017 Conservation and care of archive and library collections https://www.en-standard.eu/bs-4971-2017-conservation-and-care-of-archive-and-library-collections/
BS EN 16893:2018 Conservation of Cultural Heritage. Specifications for location, construction and modification of buildings or rooms intended for the storage or use of heritage collections