The Preservation Handbook Online

Table of Contents

I. Preservation
II. Assessment
III. Collection Assessment
IV. Agents of Deterioration
V. Monitoring collections
VI. Materials
VII. Storage
VIII. Conservation
IX. Disaster Planning
X. Housekeeping
XI. Resources / Suppliers
XII. Preservation Grants

Agents of Deterioration


Books, glues, animal proteins, hair, fur and all cellulose material make excellent food sources for biological predators when environmental conditions are right. The most common to libraries and museums are insects, mammals, and mold. The way to avoid biological damage to your collection is by active prevention. Points of entry for pests should be identified. Events that involve the transference of people or artifacts should be carefully planned. Plants, flowers, food and traveling artifacts should be scrutinized for pests. A quarantine area where items are examined for biological predators separate from the collection is recommended. Ideally the isolation area will be connected to the loading area and be gasketed properly with rubber sweeps. Establishing a safe and stable environment for collections will reduce risk of mold infestation.


Inspect for and repair any leaks, holes, or cracks in the structure. The facility should be tightly sealed where utilities such as plumbing enter. Air intake vents should have appropriate screens and filters. The surrounding vegetation should be maintained and located at least 18 inches from the perimeter of the building. Sodium vapor lights should be used as external light sources since they do not attract pests. Pieces within the collection that are vulnerable should be in sealed micro-enivronments. Setting and maintaining traps for all potential pests should be a routine part of facility management. Light traps, sticky paper, mouse traps, etc. will be a front line defense against invasion. Eliminating food sources will make your collection less inviting to biological invaders. This includes the removal of decaying insect bodies from window sills and damp cloth dusting of spider webs and cob webs. Mouse traps should be checked and emptied daily. Food and drink should be restricted from collection storage areas.

A housekeeping schedule should establish daily, weekly, monthly, and seasonal cleaning tasks. Trash removal, dusting of window sills, damp mopping of hardwood and tiled floors should be done daily. Dust contains dirt particles and moisture making it abrasive and hygroscopic. Fabrics, leather, metal and paper are sensitive to dirt and relative humidity changes. Objects that are sensitive to dust should be cleaned weekly. Carpeted areas should be vacuumed weekly.

Staff should be trained and provided with the proper tools to safely and effectively perform housekeeping functions. The cleaning treatments of old and valuable artifacts needs to be researched and discussed with a conservator.

Infestation - Pests

Detection and timely response are important when infestation occurs. Visual inspection for frass, carcasses, and damage should be part of daily routines. Common insects found in infestation are clothes moths, wood borers, dermestids, silverfish, firebrats, and cockroaches. Sticky traps are widely used to trap insects. The adhesive deteriorates with age and traps should be replaced regularly. Fly paper has caustic chemicals and should not be used in archival collections. Ultraviolet light and electrical traps are used primarily against flying insects. Electric traps can also be used effectively with termites. Early detection is most likely with pheromone traps which are pest-specific. Pest-specific traps are more expensive but extremely usefully. Effectiveness will be determined by placement of traps. Points of entry, dark places, and areas of vulnerability should be covered. Traps can also be helpful in detection and identification.

Mechanical or live traps can be used for rodents. Poisons are not recommended and can actually compound pest problems. Poisons are slow acting and can take affect after the rodent has reached an inaccessible area. Extermination can be tricky and do more harm than good. "Chemical applications, traditionally the primary means of pest control, may involve poisons, repellents, pesticides, or fumigants. Indeed, in certain cases, fumigants may still be the best alternative. Studies have shown however, that not only are many chemical fumigants dangerous to humans, but can also damage the infested artifact. As we have become more knowledgeable about potential hazards, alternate methods of pest eradication and controls have been explored."v Chemical fumigants should be the last option considered. When chemical treatment is used, further considerations should include liability of potential damage to humans and artifacts, the pest control service, and the chemicals to be used.

Infestation - Mold

Mold exists everywhere with the exception of sterile environments. Infestation is probable when environmental conditions are not within safe ranges. Changes in environmental conditions are what trigger mold spores to germinate. Mold growth generally occur at 50% RH or more, and temperatures above 70° Fahrenheit. Mold will grow on any organic food source. Depending on the ambient conditions, outbreaks can occur within 72 hours. Visual and olfactory inspection is the best way to locate mold presence. Mold sampling can identify species and concentration. When an infestation occurs response must be expedited quickly to minimize the materials that are affected. In Cunha's 1992 study "Disaster Planning and a Guide to Recovery Resources," speed is an essential factor in the recovery operation. Once mold is detected the movement of air, lowering of temperature and control of humidity is crucial in recovery. The spread to surrounding collections and staff health are also important factors that need to be addressed. Experts will need to be consulted to evaluate spore presence and growth cycle. Microbiologists, local health departments, or pest management companies will be able to track and record mold development. Objects within the collection and the building envelope will need to be monitored, assessed and treated to prevent further damage. Area contacts should be identified and incorporated in the disaster recovery plan. The unique nature of archival material, buildings and regional conditions will require different treatments. Understanding what is available and knowing the risk/benefits will aid decision makers.

Types - Mold

Molds include mushrooms, yeast, and fungi whose purpose in nature is to breakdown dead materials. Molds are highly attracted to fiberglass and cellulose rich material. Common indoor molds are Aspergillus and Alternaria, Cladosporium, Chartarum, Penicillium, and Stachybotrys. To identify any mold requires microscopic inspection and some level of expertise.

Respond - Mold

Large scale scale suppression should be contracted to a specialist. Planning should include: Sealing of the area where infestation has been identified; air flow manipulation through windows and fans, portable air handling units, and temporary duct work to gradually lower RH and temperature, as well as directing mold spores outside of the building to reduce further infestation; determine the cause of the mold production; collect spore samples to determine genus and stage of growth cycle; monitor RH and temperature levels; remove as much of the mold as possible by hand vacuuming*; informed treatment; post-treatment; document procedures and effects; devise a system to permanently identify treated objects for future knowledge; monitor results.

*Do not vacuum unstable objects. Treatment should be discussed with a conservator.


V. Montana-Ryan, V. (1995) Integrated pest management. Denver, CO.: Rocky Mountain Conservation Center.
VI Cunha, G. M.. (1992) "Disaster planning and a guide to recovery resources." Library Technology Reports 28: 533 - 624.