Mold in an Archives: Identification and Treatment The appearance of mold on archival materials is a prevalent problem for libraries and museums alike. Unfortunately, it is an often overlooked problem, because it is seen as typical for older materials or it goes unrecognized altogether. The fact that mold is preventable, although not always easily so, should encourage those who want to protect documents to ensure the environment they are held in are unsuitable for mold growth. Mold often needs a trained eye in order to be properly detected.
It can be mistaken as age spots on materials and thought to be a natural process that comes with age. Knowing what causes mold and the steps to take to prevent mold from germinating will protect archival collections from hastier and unnecessary dilapidation. In order to do this successfully, the professional must know how to identify mold and the damage it can cause. “Mould is a microscopic fungus that grows in the form of filaments called hyphae. They grow superficially on substrates, secreting enzymes in order to degrade the cellulose (in the case of paper) so that it can be absorbed as a nutrient source.
This activity causes irreversible staining. Moulds can grow even on inorganic materials such as glass and plastic, usually existing on organic materials deposited on the surfaces, such as dust” (Dadson, 103). Learning to detect and identify mold is the first step in treating and preventing mold. Mold treatments vary depending on the situation and the depth of infestation. Before learning about the treatment of mold it is vital to learn how to identify mold in order to extract it from an archival area before it permeates the collection and becomes a conservation emergency.
Mold may be brilliant colors or black and white, depending on the type. Mold can develop on leather, cloth, paper, etc” (Depew, 72). Although this description does not necessarily immediately identify mold, it is a starting point to inform the professional of the diversity of color mold can take and where it can grow. For example, one may be used to mold being white/green in color because that is what they have previously been exposed to which can lead to overlooking mold that appears as a dull brown spot.
Mold can be found in two different stages: active and dormant. Active mold is growing and the spores are germinating while dormant mold is no longer in an atmosphere where it is growing and thriving. “Active mold produces enzymes that can digest organic materials such as paper and textiles, weakening or destroying them. Colorful blooms can cause stains that cannot be removed” (Ford, 11). It is imperative to note that dormant does not mean dead but inactive, dormant spores can and will under the right conditions become active again.
Lavendar concisely describes the appearance of the two types, “active mold appears fuzzy and slimy and may smear when brushed while dormant spores appear dry and powdery” (57). Determining the type of mold sighted will help determine if the current conditions are positive for mold growth or if it is stagnant and needs to be eradicated. Also determining the type will help in deciding the best treatment option to eliminate the mold spores. Another problem when locating mold is determining if a suspicious spot or place on a piece of material is in fact mold or not.
It can easily be misidentified as dust or discoloration that comes with age and wear and tear. Balloffet and Hille describe the growth and appearance of mold as “uneven patterns or in little dots”. It can grow on horizontal or vertical surfaces whereas dust lays evenly and thick typically only on horizontal surfaces. Under a microscope mold appears as a web of little hairs or plantlike growth. (Balloffet and Hille, 18). When in doubt, the naked eye may not provide enough information to determine the presence of mold. Thankfully, a closer look will leave no doubt whether it is the presence of fungi or merely dust.
At first glance it may appear to resemble dust but if one takes the time to observe and notice it is only in one area and not spread evenly then the eye will train itself to recognize its presence rather than dismiss it easily. Cornell University Library found that when searching for mold, “mites known as book lice can be a useful indicator of mold. These tiny grey/white insects inhabit the inner margins of damp books and feed on microscopic mold embedded in the paper. Hidden mold can also be detected with ultraviolet light, exposure to which causes the fungi to turn fluorescent.
Mold can also be detected by the musty odor common to damp basements”. Possessing the knowledge of how to find mold and know what factors it thrives in will aid any archives/library/museum professional in protecting their collection by observing the environment. There are many factors that must be considered before one can choose the best treatment option. The extent of the mold growth, current environment, flood factors, and the medium on which the mold is growing are all examples of factors that will aid in choosing the best treatment option.
According to the NEDCC Emergency Salvage of Moldy books and Paper, there are three stabilizing techniques that should be carried out after mold is detected. First, isolate the affected item(s). Secondly, determine the cause of mold growth and lastly modify the environment to ensure mold growth is no longer conductive. These are the basics steps necessary to begin the process of eliminating mold from items and collections. Isolating the item(s) will prevent the spores from contaminating objects surrounding it. It is important to be aware of the surroundings and knowing that when cleaning the mold the spores can and will travel.
By determining the cause the professional will be better educated on preventing the mold growth and stopping possible growth from happening. For example, a leaking fire sprinkler may cause mold in a certain area and by locating and fixing the sprinkler will prevent the problem from continuing. This will modify the environment and hopefully prevent the growth of mold in the future and force the professional to be aware of the environment which the collection is housed. Once all the information is gathered on the type of mold and the extent of the growth, the professional can then approach the treatment and elimination.
Now the material of the item will decide who treatment will take place. Textiles, film, and paper are affected by mold differently and therefore require different approaches on treatment. Mold on textiles should be isolated, sealed in a polyethylene bag until treatment. Treatment can be removal with a low powered vacuum suction (Harvey and Mahard, 324). For the surface cleaning of paper the NEDCC staff suggests if the mold is active it “should first be stabilized by providing the affected materials with a prolonged environment of low relative humidity, generally below 50 percent, so that the mold goes dormant”.
Lavendar suggests freezing the material after loosely wrapping in freezer paper to cause the mold to become dormant (58). Now that the mold is dormant the process for eliminating it can take place. Since the mold is dry and powdery it can be extracted from the material with more ease and precision. Rubber cleaning sponges without additives can be used to clean light mold. The sponges must be dry and as the surface gets dirty, cut it away. Do not wash and reuse, throw away in order to avoid spreading the spores (Balloffet and Hille, 84).
Other options for cleaning mold suggested by Harvey but have some negative effects are gamma irradiation which is an effective non-chemical method, but has possible harmful effects on cellulose and protein and has not yet been widely adopted. Fungicides used by conservators have their problems. Thymol is toxic and banned in some places, orthophenyl phenol can cause health problems. Ethylene Oxide is a carcinogen so toxic to both humans and fungi (Harvey, 133-134). So, if the mold cannot be cleaned with a dry sponge or brush it is advisable to entrust it to a professional conservator to handle.
Overall, mold has the ability to wreak havoc on archival collections. By understanding how mold grows, what it is attracted to and how to safely eradicate it, the professionals will have the ability to better care for their collections. Awareness is they key factor to this process. Allowing wet and warm conditions to foster in an archival environment will encourage mold to grow and ignoring mold as “typical” on materials will encourage the same. Thankfully with a little education and knowledge mold can usually be prevented and removed.