Mold
In Hawaii's Libraries

What is mold?

• Mold and mildew are generic terms for various types of fungi.
• Fungi produce enormous quantities of microscopic spores.
• These spores are always present in the environment and are spread by air currents.
• When these spores find a hospitable environment they will germinate.
• If small patches of germinating spores are ignored you will get a mold bloom or outbreak.
• A mold bloom is basically zillions of fungi producing enormous quantities of spores.

What causes mold to grow?

• Moisture is required for spores to germinate
• Mold will grow on any organic host material that offers suitable nutrients, including paper, adhesives, bookbindings, microfilm, slides, videotapes, dust, etc.
• Books and paper provide a perfect host for mold to germinate. They are hygroscopic and absorb and hold moisture.
• A mold bloom in a library indicates that there has been an increase in relative humidity. This could be caused by any number of things:
• Changes in the natural environment, i.e. rainy season in Hawai'i.
• Fluctuation in interior environment caused by turning off AC at the end of the day and on weekends. Causes library to warm up, condensation to form on materials.
• Construction/building disaster, i.e. roofing, asbestos abatement.
• Natural disasters, i.e. hurricanes.

Why is mold a problem?

• Health Concerns: All molds can have serious health consequences including respiratory problems, skin and eye irritation and infections. Mold spores enter the body by inhalation and through small breaks in the skin.
• Costs associated with mold outbreaks: Clean up; community does not have access to library; replacement of materials.
• Damage to materials: mold can stain bookbindings and weaken paper; it can completely digest the image layer of photos, slides, and microfilm; it also destabilizes the emulsion and can cause it to become water-soluble.

How to combat mold (prevention)?

• Controlled environment is essential to preventing large-scale outbreaks of mold. This means:
• Moderate, constant temperature (68-72 degrees F). Turning off Air conditioning causes fluctuations in temperature and the relative humidity to increase.
• Low, constant relative humidity (if possible less than 60%, max. 65%). Reheat systems can be installed to remove moisture from outside air brought in through the HVAC. Room dehumidifiers need to be emptied or they can re-introduce moisture into air; they can also be a source of water leaks.
• Good air circulation. Fans can be installed to improve air circulation.
• Good Housekeeping: Dust books and library materials regularly
• Mold will stop growing and become inactive or dormant in a controlled environment, however the spores will remain viable on the host material. Increases in relative humidity or other moisture will facilitate a mold bloom.
• Regularly monitor library for mold.

How to combat mold (response to mold bloom/outbreak)?

• Verify that the problem is mold. Stains from earlier mold damage or silverfish damage can look like mold.
• Respond immediately and organize a team to cleanup the mold.
• Mold can be sampled by an environmental consultant and/or analyzed by a laboratory specializing in microbiology; these tests can be very expensive - from hundreds to thousands of dollars.
• Freezing mold spores will render them dormant but will not kill them. As soon as conditions are favorable dormant spores will reactivate.
• If possible isolate contaminated materials by bagging them.
• Provide protective gear:
• Respirator with a HEPA (High Efficiency Particulate Arrestant) filter or dust masks that filter mold (meeting standard TC-21C-132) such as 3M 8500 mask.
• Disposable vinyl gloves and protective clothing
• Clean Materials
• Fungicides are not recommended for treating mold in libraries due to the concerns about both toxicity and long-term effects on collection materials. Also these compounds provide no residual protection. The only way to stop mold is to control relative humidity and clean materials.
• Chemicals used to clean walls (e.g. Lysol, Clorox) are not appropriate to use on books.
• Vacuum with HEPA filter should be used to prevent spreading or further embedding the mold spores.
• Vacuum binding, spine, and text block.
• To remove additional mold residue from bindings use a commercial wipe with a small amount of isopropyl alcohol. Always test a corner of the binding to be sure the alcohol will not stain or damage the binding.
• Air circulation is important. After you have cleaned mold off of materials install fans in area.
• If you have a small outbreak, you could take your materials outside on a nice, dry sunny day to vacuum them. A brief exposure to ultra-violet rays will kill mold spores. However, Ultra- violet can cause long-term, irreversible damage to library materials. Leaving lights on in a library 24/7 is not a treatment option.
• Clean all work surfaces, including book trucks, shelves, and walls thoroughly. Vacuum then wipe all surfaces with Simple Green or Lysol type solution.
• Clean or remove carpets and drapes in area.
• Clean and disinfect AC coils, filters, drip pan, and ductwork for HVAC system.
• Monitor Library
• Regularly check stacks for evidence of mold, especially during the rainy season.
• Monitor temperature and humidity daily in problem areas. A hygrothermograph will record fluctuations in temperature and humidity over a 24 hr. period.

Please refer to the Mold resource list.

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