Mold control and prevention (library and archival science)

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An example of mold damage Schimmelschaden in historischer Akte2.JPG
An example of mold damage

Mold control and prevention is a conservation activity that is performed in libraries and archives to protect books, documents and other materials from deterioration caused by mold growth. Mold prevention consists of different methods, such as chemical treatments, careful environmental control, and manual cleaning. Preservationists use one or a combination of these methods to combat mold spores in library and archival collections.

Contents

Due to the resilient nature of mold and its potential for damage to library collections, mold prevention has become an important activity among preservation librarians. Although mold is naturally present in both indoor and outdoor environments, under the right circumstances it can become active after being in a dormant state. Mold growth responds to increased moisture, high humidity, and warm temperatures. [1] Library collections are particularly vulnerable to mold since mold thrives off of organic, cellulose-based materials such as paper, wood, and textiles made of natural fibers. Changes in the moisture in the atmosphere can lead to mold growth and irreparable damage to library collections. [2]

Mold

Mold is a generic term for a specific type of fungi. Mildew may also refer to types of mold. Since there are so many species of mold, their appearance varies in color and growth habit . In general, active mold has a musty odor and appears fuzzy, slimy, or damp. Inactive mold looks dry and powdery. [3] [4]

Mold propagates via spores, which are always present in the environment. Mold spores can be transferred to an object by mechanical instruments or air circulation. When spores attach to another organism, and the environment is favorable, they begin to germinate. Mold produce mycelium which growth pattern resembles cobwebs. Mycelium allows the mold to obtain food and nutrients through the host. Inevitably, the mycelium produces spore sacs and release new spores into the air. [5] Eventually the spores land on new material, and the reproductive cycle begins again.

Identifying mold can be a challenge, because some species resemble dust, dirt, or spiderwebs. In addition, staining caused by mold can be confused with water damage. Ultraviolet light and magnification are two tools to aid in identifying mold on library collections. [6]

Poor air circulation, moisture, high temperatures, and environmental humidity are the main causes of mold outbreaks in library collections. When the temperature is above 70 degrees Fahrenheit and the relative humidity is above 55 percent, mold begins to develop. [7] Collections kept in basements or environments with uncontrolled temperature and humidity are most likely to be impacted by a mold outbreak .

Mold is a dangerous library pest because of the damage it causes to the collections. Mold thrives off of paper and books; these objects provide the fungi a source of nutrition, namely the sugar and starches present in the cellulose materials. [8] Mold feeds on cloth, leather, glues, adhesives, cellulose starch and starches in the sizing. Frequently, mold is noticed on the bindings long before it begins on the text blocks . By feeding on books, mold can cause the paper to become thin, soft, or spongy. Images and decorative elements can be completely destroyed or, at the very least, become stained.

Impact on Materials

When a book or paper becomes moldy, the fungi will digest its food source, paper and cloth (such as book covers and bindings), in order to survive. This process stains and destroys books, papers, and other library collections over time.[ citation needed ] During their growth mold and mildew produce citric, gluconic, oxalic, or other organic acids that can damage paper, leather, cloth, etc. They also at times produce color bodies, leading to staining which is difficult to remove. [9] Mold will continually grow until it uses up its food source, which means a library collection could be totally consumed. Unless every mold spore is treated, the issue will just return. Mold's enduring nature makes treatment difficult and prevention all the more necessary.

Prevention

Conservation staff drying mold-damaged materials CCAHAStaff drying.jpg
Conservation staff drying mold-damaged materials

The only way to control mold is by altering conditions conducive to its growth. [10] The generally accepted threshold for mold growth is about 15% moisture content because the predominant cause of mold is excess water. Excess water can come from liquid water, as a result of leaks, or water vapor, as a result of high relative humidity due to improper storage, faulty humidifiers, or HVAC malfunctions. While most research shows that fungal growth is most prevalent in conditions in which relative humidity is above 60%, humidity levels below this threshold alone will not prevent mold growth, given the fact that favorable germination environments vary from species to species. [11]

Environmental Controls

Many libraries monitor a building's atmosphere through the use of HVAC systems. These built in ventilation systems help to combat mold growth that occurs as a result of relative humidity levels greater than 65% and temperature greater than 70° Fahrenheit, as well poor air circulation. [12] Proper use and monitoring of HVAC systems can help to prevent mold problems before they occur. Air ventilation removes existing mold spores from the air and keeps the atmosphere relatively dry and cool. Effective HVAC systems have a good system design and the ability to provide environmental control over entire building areas. Proper maintenance of equipment also lowers the chances that issues will arise due to system outages . [13] At 70° Fahrenheit and 50% relative humidity, the equilibrium moisture content of the environment would be 9.2%, low enough to prevent mold growth. However, proper air flow and air exchange is required to effectively disrupt the boundary layers of air around room contents, which can have high water vapor levels within the surrounding dry air and promote mold amplification.

Manual solutions

Manual methods such as HEPA filtered vacuuming serves as a backup to eliminating mold via environmental control. HEPA vacuums possess air filters that do not allow mold to be spread into the air again. Installing drying fans, wiping dry books and surrounding furniture, as well as air ducts and shelves will also help to prevent further infestations. In extreme cases, some books and items are discarded to protect the rest of the collection from being affected. These preservation activities are provided by available library staff or hired contractors. [14]

Storage

Proper storage practices can be effective in preventing mold growth. Storing materials away from exterior walls and damp areas like basements can reduce the risk of mold growth. [15] In addition, the use of desiccants can control humidity inside enclosed containers. [16]

Safe Handling

Proper handling of affected or damaged materials prevents mold from spreading. Because mold spores are released into the air, it is recommended to wear an NIOSH-rated respirator before coming into contact with affected materials. [17] Nitrile gloves should be worn to protect the skin from contact with mold. [18] In extreme cases, a full-body hazmat suit may be required. Materials must always be treated on a surface that can be cleaned with bleach or on neutral, disposable materials such as unprinted newsprint.

Potential Health Concerns

Mold is harmful to materials, and may cause mold health issues in humans. When a library collection experiences a mold outbreak, actions need to be taken to ensure preservation of materials and the good health of the people involved. Mold is more hazardous to those who have allergies or suffer from respiratory problems such as asthma. [19] Some mold species can irritate other parts of the body through prolonged exposure. In some cases, protective clothing is necessary when handling mold found on library collections.

Monitoring

Mold spores are always present in the environment and when conditions are favorable, mold will occur. [20] Regular monitoring of the collection through visual inspection and environmental controls is essential to prevent an outbreak.

Mold leaves a visual indication of its presence. Though mold can be any color, gray and black spots coupled with a musty odor can indicate the presence of mold. [21] Books with these indicators can be isolated and treatment steps can be implemented. Books in the surrounding area can be monitored in case of further infestation. Presence of water or condensation and dust are other factors to look out for that can encourage mold growth. Regular cleaning and inspections will help monitor for mold growth.

The control and regular monitoring of temperature and humidity levels is vital to prevent mold growth. Guidelines suggest that temperatures be maintained between 65°-70° Fahrenheit and relative humidity between 45%-65%. [22] HVAC systems can be utilized and monitored to ensure these levels are maintained. Temperature and humidity values can be systematically measured and recorded to document conditions, to alert of severe fluctuations, and to indicate the functionality of the climate control systems. [23] The systems themselves should be regularly checked for accuracy and functionality.

Treatments for Mold Damage

Chemical Treatments

Preservation librarians use a number of different chemicals to prevent the growth of mold spores. Chemical compounds such as ethylene oxide, thymol, and orthophenyl phenol are regularly used. [24] Chlorine dioxide is a chemical that is growing in popularity due its safety level for library employees and patrons. These chemicals act as effective sporicides in a variety of library settings. They are applied on books and surrounding shelves by manual wiping or using chlorine packets that release the chemicals in gaseous form into the air. [25]

Chemical treatments are often used in enclosed storage areas with little air circulation. They are also used to deal with emergency situations involving mold outbreaks caused by pipe leaks in buildings. In 2000, the University of Oklahoma Libraries conducted an evaluation of the effects of chlorine packets on mold growth. Paper items that had been exposed to the substance showed lower overall pH levels than items that had not been treated. Although long-term effects of chemical treatments on paper permanence and other library materials have not been documented, libraries use this newer method of controlling mold in the stacks. [26]

Freeze Drying and UV Light

Freeze drying or ultraviolet light exposure are other ways to inhibit mold growth, although they do not kill mold spores permanently. Eliminating mold through these methods is challenging due to paper degradation caused by light exposure over time. There are also some mold species that have preferences for colder temperatures. Freezing and UV exposure are used as a temporary means to stop mold from spreading throughout library collections. [27]




See also

Related Research Articles

Mold Diverse group of fungi

A mold or mould is a fungus that grows in the form of multicellular filaments called hyphae. In contrast, fungi that can adopt a single-celled growth habit are called yeasts.

Indoor air quality Air quality within and around buildings and structures

Indoor air quality (IAQ) is the air quality within and around buildings and structures. IAQ is known to affect the health, comfort, and well-being of building occupants. Poor indoor air quality has been linked to sick building syndrome, reduced productivity, and impaired learning in schools.

Mildew

Mildew is a form of fungus. It is distinguished from its closely related counterpart, mould, largely by its color: moulds appear in shades of black, blue, red, and green, whereas mildew is white. It appears as a thin, superficial growth consisting of minute hyphae produced especially on living plants or organic matter such as wood, paper or leather. Both mould and mildew produce distinct offensive odors, and both have been identified as the cause of certain human ailments.

Humidifier

A humidifier is a device, primarily an electrical appliance, that increases humidity (moisture) in a single room or an entire building. In the home, point-of-use humidifiers are commonly used to humidify a single room, while whole-house or furnace humidifiers, which connect to a home's HVAC system, provide humidity to the entire house. Medical ventilators often include humidifiers for increased patient comfort. Large humidifiers are used in commercial, institutional, or industrial contexts, often as part of a larger HVAC system.

The conservation and restoration of photographs is the study of the physical care and treatment of photographic materials. It covers both efforts undertaken by photograph conservators, librarians, archivists, and museum curators who manage photograph collections at a variety of cultural heritage institutions, as well as steps taken to preserve collections of personal and family photographs. It is an umbrella term that includes both preventative preservation activities such as environmental control and conservation techniques that involve treating individual items. Both preservation and conservation require an in-depth understanding of how photographs are made, and the causes and prevention of deterioration. Conservator-restorers use this knowledge to treat photographic materials, stabilizing them from further deterioration, and sometimes restoring them for aesthetic purposes.

With respect to cultural property, conservation science is the interdisciplinary study of the conservation of art, architecture, technical art history and other cultural works through the use of scientific inquiry. General areas of research include the technology and structure of artistic and historic works. In other words, the materials and techniques from which cultural, artistic and historic objects are made. There are three broad categories of conservation science with respect to cultural heritage: 1) understanding the materials and techniques used by artists, 2) study of the causes of deterioration, and 3) improving methods/techniques and materials for examination and treatment. Conservation science includes aspects of chemistry, physics and biology, engineering, as well as art history and anthropology. Institutions such as the Getty Conservation Institute specialize in publishing and disseminating information relating to both tools used for and outcomes of conservation science research, as well as recent discoveries in the field.

Conservation and restoration of parchment

The conservation and restoration of parchment constitutes the care and treatment of parchment materials which have cultural and historical significance. Typically undertaken by professional book and document conservators, this process can include preventive measures which protect against future deterioration as well as specific treatments to alleviate changes already caused by agents of deterioration.

Conservation and restoration of textiles Processes by which textiles are cared for and maintained to be preserved from future damage.

The conservation and restoration of textiles refers to the processes by which textiles are cared for and maintained to be preserved from future damage. The field falls under the category of art conservation as well as library preservation, depending on the type of collection. In this case, the concept of textile preservation applies to a wide range of artifacts, including tapestries, carpets, quilts, clothing, flags and curtains, as well as objects which ‘’contain’’ textiles, such as upholstered furniture, dolls, and accessories such as fans, parasols, gloves and hats or bonnets. Many of these artifacts require specialized care, often by a professional conservator.

Indoor mold Fungal growth that develops on wet materials

Mold or mould, also sometimes referred to as mildew, is a fungal growth that develops on wet materials. Mold is a natural part of the environment and plays an important part in nature by breaking down dead organic matter such as fallen leaves and dead trees; indoors, mold growth should be avoided. Mold reproduce by means of tiny spores. The spores are like seeds, but invisible to the naked eye, that float through the air and deposit on surfaces. When the temperature, moisture, and available nutrient conditions are correct, the spores can form into new mold colonies where they are deposited. There are many types of mold, but all require moisture and a food source for growth.

Conservation and restoration of movable cultural property is a term used to denote the conservation of movable cultural property items in libraries, archives, museums and private collections. Conservation encompasses all the actions taken toward the long-term preservation of cultural heritage. Activities include examination, documentation, treatment, and preventive care, which is supported by research and education. Object conservation is specifically the actions taken to preserve and restore cultural objects. The objects span a wide range of materials from a variety of cultures, time periods, and functions. Object conservation can be applied to both art objects and artifacts. Conservation practice aims to prevent damage from occurring. This is called ‘preventive conservation’. The purpose of preventive conservation is to maintain, and where possible enhance, the condition of an object, as well as managing deterioration risks, such as handling and environmental conditions. Historically, object conservation was focused on the category of fine arts but now many different types of objects are conserved. Each type of object material, typically denoted by organic or inorganic then the specific medium, requires a specialized professional conservator and often requires collaborative work between museum staff, scientists, and conservators.

Interstitial condensation is a type of condensation that may occur within an enclosed wall, roof or floor cavity structure, which can create damping.

Collections maintenance

Collection maintenance is a form of collections care that consists of the day-to-day hands on care of collections and cultural heritage. The primary goal of collections maintenance is to prevent further decay of cultural heritage by ensuring proper storage and upkeep including performing regular housekeeping of the spaces and objects and monitoring and controlling storage and gallery environments. Collections maintenance is closely linked to collections care and collections management. The professionals most involved with collections maintenance include collection managers, registrars, and archivists, depending on the size and scope of the institution. Collections maintenance takes place in two primary areas of the museum: storage areas and display areas.

Conservation and restoration of books, manuscripts, documents and ephemera

The conservation and restoration of books, manuscripts, documents and ephemera is an activity dedicated to the preservation and protection of items of historical and personal value made primarily from paper, parchment, and leather. When applied to cultural heritage, conservation activities are generally undertaken by a conservator. The primary goal of conservation is to preserve the lifespan of the object as well as maintaining its integrity by keeping all additions reversible. Conservation of books and paper involves techniques of bookbinding, restoration, paper chemistry, and other material technologies including preservation and archival techniques.

Integrated pest management in museums, libraries, archives and private collections is the practice of monitoring and managing pest and environmental information with pest control methods to prevent pest damage to collections and cultural property. Preserving cultural property is the ultimate goal for these institutions. The pests come in many different forms: insects, mites, rodents, bats, birds, and fungi and the two most common types are insects and fungi. It is widely recommended that every museum have some form of pest control in place and monitoring system to protect their collection and that museums review their storage and museum facilities to determine how to best control and prevent pest infestations while utilizing an Integrated Pest Management plan.

Conservation and restoration of clocks

The conservation and restoration of clocks refers to the care given to the physical and functional aspects of time measuring devices featuring “moving hands on a dial face” exclusive of watches. Care for clocks constitutes regulating the external environment, cleaning, winding, lubrication, pest-management, and repairing or replacing mechanical and aesthetic components to preserve or achieve the desired state as specified by the owner. Clocks are typically composed of multiple types of materials such as wood, metal, paint, plastic, etc., which have unique behaviors and environmental interactions, making treatment options complex. The materials used and the complexity of clockwork warrant having a Horological Conservator complete the work.

Conservation and restoration of bone, horn, and antler objects

Conservation-restoration of bone, horn, and antler objects involves the processes by which the deterioration of objects either containing or made from bone, horn, and antler is contained and prevented. Their use has been documented throughout history in many societal groups as these materials are durable, plentiful, versatile, and naturally occurring/replenishing.

Conservation and restoration of paintings

The conservation and restoration of paintings is carried out by professional painting conservators. Paintings cover a wide range of various mediums, materials, and their supports. Painting types include fine art to decorative and functional objects spanning from acrylics, frescoes, and oil paint on various surfaces, egg tempera on panels and canvas, lacquer painting, water color and more. Knowing the materials of any given painting and its support allows for the proper restoration and conservation practices. All components of a painting will react to its environment differently, and impact the artwork as a whole. These material components along with collections care will determine the longevity of a painting. The first steps to conservation and restoration is preventive conservation followed by active restoration with the artist's intent in mind.

The conservation and restoration of film is the physical care and treatment of film-based materials. These include photographic film and motion picture film stock.

The conservation and restoration of herbaria includes the preventive care, repair, and restoration of herbarium specimens. Collections of dried plant specimens are collected from their native habitats, identified by experts, pressed, and mounted onto archival paper. Care is taken to make sure major morphological characteristics are visible. Herbaria documentation provides a record of botanical diversity.

Conservation and restoration of wooden artifacts

The conservation and restoration of wooden artifacts refers to the preservation of art and artifacts made of wood. Conservation and restoration in regards to cultural heritage is completed by a conservator-restorer.

References

  1. ↑ Parrott, Kathleen. "MOLD BASICS" (PDF). Virginia Cooperative Extension. Virginia Tech. Retrieved 29 March 2020.
  2. ↑ Baker, Whitney. "Preservation Perspectives: Mold in the Stacks: A Universal Problem. Kentucky Libraries. 65(3)(Summer 2001):20-22.
  3. ↑ Brown, Karen E.K. (November 13, 2013). "Mold in the Library: Prevention and Response" (PDF). University Libraries University at Albany State University of New York. University Libraries, University at Albany. Retrieved November 8, 2019.
  4. ↑ "Water Damage Guide". Saturday, 10 April 2021
  5. ↑ "EMERGENCY MANAGEMENT: 3.8 Emergency Salvage of Moldy Books and Paper". NEDCC website. Northeast Document Conservation Center(NEDCC). Retrieved November 8, 2019.
  6. ↑ Brown, Karen E.K. (November 13, 2013). "Mold in the Library: Prevention and Response" (PDF). University Libraries University at Albany State University of New York. University Libraries, University at Albany. Retrieved November 8, 2019.
  7. ↑ Nyberg, Sarah (November 1987). "Invasion of the Giant Mold Spore". Conservation OnLine (CoOL). Solinet Preservation Leaflets. Retrieved November 8, 2019.
  8. ↑ Parrott, Kathleen. "Mold Basics" (PDF). Virginia Cooperative Extension. Virginia Tech. Retrieved 29 March 2020.
  9. ↑ "Mold : Preservation Resources : Minnesota Library Storage (MLAC) : Products & Services : Minitex". www.minitex.umn.edu. Retrieved 2019-11-01.
  10. ↑ "Mold | Library Preservation and Conservation Tutorial". chinapreservationtutorial.library.cornell.edu. Retrieved 2019-11-01.
  11. ↑ "Mold, Pest, and Water Damage Response – Staff Website – U of I Library". www.library.illinois.edu. Retrieved 2019-11-01.
  12. ↑ Nyberg, Sandra. "Invasion of the Giant Mold Spore" . Retrieved 1 November 2019.
  13. ↑ Brown, Dors R. "Collection Disaster: Mold in the Stacks." College & Research Libraries News. 64(5) (2003):304-306.
  14. ↑ Alleman, Steve. "Coping with an Outbreak of Mold." LLA Bulletin. 61(4) (Spring 1999):217-220.
  15. ↑ "Managing a Mold Invasion |" (PDF). museumtextiles.com/uploads/7/8/9/0/7890082/managing_a_mold_invasion.pdf. Retrieved 2019-11-01.
  16. ↑ "Mold | Library Preservation and Conservation Tutorial". chinapreservationtutorial.library.cornell.edu. Retrieved 2019-11-01.
  17. ↑ Stauderman, Sarah (2013-02-21). "I've got mold in my files". Smithsonian Institution Archives. Retrieved 2019-11-03.
  18. ↑ "Gloves or No Gloves? On the Proper Handling of Rare Books & Manuscripts". Portland State University Library. 2015-06-04. Retrieved 2019-11-03.
  19. ↑ "Mold 101: Effects on Human Health". Poison Control: National Capital Poison Center. Retrieved 29 March 2020.
  20. ↑ Livingston, Preston. "Mold Prevention and Remediation in a Library Environment". Questia. Retrieved 1 November 2019.
  21. ↑ "Mold : Preservation Resources : Minnesota Library Storage (MLAC) : Products & Services : Minitex". www.minitex.umn.edu. Retrieved 2019-11-01.
  22. ↑ Nyberg, Sandra. "Invasion of the Giant Mold Spore" . Retrieved 1 November 2019.
  23. ↑ Ogden, Sherelyn. "2.1 Temperature, Relative Humidity, Light, and Air Quality: Basic Guidelines for Preservation". Northeast Document Conservation Center. Retrieved 1 November 2019.
  24. ↑ Southwell, Kristina L. "The Use of Chlorine Dioxide as a Mold Treatment and its Effect on Paper Acidity: a case study." The Journal of Academic Librarianship. 28(6) (2002): 400-405.
  25. ↑ Southwell, Kristina L. "Chlorine Dioxide: a treatment for mold in libraries." Archival Products. 10(3) (2003)
  26. ↑ Southwell, Kristina L. "The Use of Chlorine Dioxide as a Mold Treatment and Its Effect on Paper Acidity: a case study." The Journal of Academic Librariansip. 28(6) (2002): 400-405.
  27. ↑ Baker, Whitney. "Preservation Perspectives: Mold in the Stacks: A Universal Problem." Kentucky Libraries. 65(3) (Summer 2001): 20-22.
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