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NLS Technical Circulars

Braille Preservation and Salvage Guidelines

2003, 03-01

Braille Preservation and Salvage Guidelines.

These guidelines are intended for use by the national network of libraries serving blind and physically handicapped individuals. They were developed by Edwin L. Pitts Jr., NLS production control specialist, to help librarians plan and maintain programs for preserving collections in the event of water disasters and mold outbreaks. This text may be accessed at <www.loc.gov/nls/technical/circulars/braillepreservationguidelines.html>. The bibliography; Appendix A: Basic Emergency Checklist, Supplies, and Equipment; and Appendix B: Emergency Management Suppliers and Services are available upon request from the Reference Section via telephone at (202) 707-5100 or e-mail at nlsref@loc.gov.

Need for Disaster Planning.

A disaster plan can reduce vulnerability to risk and forestall potential emergencies. Once established it should be subject to periodic risk-assessment review, updating of maintenance procedures, and revision of collection priorities.

To be effective, disaster planning should be formally assigned to one person, perhaps assisted by a planning team. The planner should define the scope and goals of the plan and establish a timetable for implementation, determined by an institution-wide survey of risks (such as geographic and climatic hazards; building and site problems; and difficulties of maintaining fire protection systems, electrical systems, and plumbing).

A disaster plan should contain: (1) basic information about the institution and the plan (e.g., completion date, scheduled updates, lines of authority, and possible events covered); (2) actions to be taken if advance warning is available; (3) first response procedures, including initial contacts in each type of emergency, immediate steps to take, and notification of staff or teams; (4) emergency procedures for each emergency, including actions to be taken during the event and subsequent salvage actions; (5) rehabilitation plans for getting the institution back to normal; and (6) appendixes (such as evacuation/floor plans, identity of emergency response team members and their responsibilities, location of keys, collection priorities, arrangements for relocating the collection, a list of in-house supplies for use in emergencies, and a list of outside suppliers of emergency services).

Basic Preservation Guidelines.

Controlling temperature, relative humidity, light, and pollution is critical because high levels of any of these may contribute to the breakdown of materials.

Periodic cleaning to remove dust or other foreign substances is also important to preserving braille materials. How frequently this should be done depends on how rapidly dust or dirt accumulates in book storage areas. A time-consuming task, cleaning sometimes tends to be overlooked or postponed. This is a mistake. In addition to maintaining the collection's condition, the cleaning process provides an opportunity to check for mold growth and insect infestation.

For braille volumes, surface or dry cleaning with a soft brush or magnetic wiping cloth is the simplest method. If books are covered with a heavy layer of dust, they can be vacuumed with a soft brush (provided care is taken not to push dirt down into the braille pages). Shelves are also best cleaned with a magnetic wiping cloth or, again, if heavy dust is present, with a vacuum designed to prevent recirculation of dust through the exhaust, such as one with a HEPA (high efficiency particulate) filter. Thick accumulations of dust and dirt on shelves can be removed by washing with a mild detergent or, preferably, by using fast-drying spray cleaning agents that avoid the possibility of spillage.

Finally, floors and carpets should be vacuumed regularly and washed or cleaned as necessary. Sweeping of floors is not recommended because it can stir up and scatter dust.

Emergency Salvage of Wet Braille Volumes.

A rapid response is key to emergency recovery since braille volumes will begin to distort immediately after becoming wet.

In an effort to formulate an effective and reliable recovery process, NLS requested that Belfor Fire and Water Damage Restoration Services of Ft. Worth, Texas, test three different methods of drying original braille materials after they had been submerged in water for 60 seconds. The three methods were: dehumidification, air drying, and freeze drying. The tested braille materials included magazines (coverless and saddle-stitched) and two book types, one metal-bound and the other plastic-bound. Both types of books had cardboard covers but used different glues for adhesion.

Upon completion of the drying process, Belfor returned the dried materials to NLS for inspection. That inspection showed mostly similar results. When applied to braille magazines, all three drying techniques left a totally unreadable product. Applied to plastic-bound books, all of the tests caused the bindings to fall apart and made the text unreadable. In the case of the metal-bound books, however, the braille text was mostly readable (although with some low dots) after dehumidification and freeze drying and partially readable after air drying, but the graphics were unreliable in each instance.

Based on the Belfor test results, NLS recommends that libraries discard magazines or books that get soaking wet and replace them through either the Replacement Braille Program or Web-Braille. If a volume is damp or only slightly wet in some places, such as along the edges, NLS recommends air drying, the most common and least expensive drying method. On the other hand, air drying requires a lot of space and labor and often results in badly distorted bindings. Also, materials must be carefully monitored for mold growth during the drying process.

To discourage mold growth, air drying should take place in a clean, dry environment where the temperature is approximately 70 degrees F and the humidity is below 50 percent. The air should be kept moving at all times using fans (aimed into the air and away from the drying books). Books should be stood on end and fanned slightly open to catch the flow of air. Books with only wet edges can be dried successfully in approximately two weeks.

Emergency Salvage of Moldy Braille Volumes.

Mold and mildew are generic terms that refer to various types of fungi, of which there are more than 100,000 known species. This abundance of species means mold growth patterns and activity in particular situations can be unpredictable.

In general, mold propagates by disseminating large numbers of spores, which then germinate under the right conditions. The most important condition is the level of moisture in the air (relative humidity) or in the object on which the mold is growing. Mold growth is almost inevitable if the relative humidity is over 70 percent for an extended period, but some species of mold grow at lower levels of relative humidity as well. High temperature, stagnant air, and darkness also promote mold growth in the presence of moisture.

Reducing humidity is essential to stopping mold growth. Some other basic salvage rules are: (1) do not turn up the heat, since additional heat in the presence of moisture will make mold grow faster; (2) dry damp collections or, if this cannot be done within 48 hours, freeze the affected material until it can be dried and cleaned; (3) consider health risks, since a few mold species are toxic to people and can lead to debilitating allergies, and make sure those working with moldy objects are properly protected; and (4) avoid quick and easy cures. For example, spraying Lysol on objects or cleaning them with bleach may cause additional damage to items or toxicity to people, and these approaches are frequently ineffective. Also, treating mold-infested collections with fumigants is problematic. While ethylene oxide will kill active mold and mold spores, other chemicals used in such treatments are less effective. Moreover, all of these chemicals can harm both collections and people, and none will keep mold from recurring.

Responses to Small or Moderate Mold Outbreaks.

Specific steps for dealing with small or moderate outbreaks are outlined below.

  1. Determine what is causing the mold growth and how to rectify the problem. Look first for a water leak (or some other obvious source of moisture) and then for possible causes of elevated relative humidity (such as a heating, ventilating, or air conditioning problem). Also check for mold in dirty areas with poor air circulation.
  2. Modify the environment so that it is no longer conducive to mold growth. Among other things, remove any standing water; bring in dehumidifiers; open the windows (unless the humidity is higher outside) and use fans to circulate the air; reduce the relative humidity to 50 percent or lower; and maintain temperature at 70 degrees F or below. Also, get a monitoring instrument to measure relative humidity and temperature accurately, and record the measurements several times a day.
  3. Implement safety precautions for staff and others working with moldy items. First, consult a mycologist to determine whether toxic mold species are present (a local hospital or university should be able to provide a reference). If toxic molds are present, put on disposable plastic gloves, clothing, and face masks before attempting any salvage. (Pollen dust masks available in drug and hardware stores are not- adequate.) If disposable clothing is unavailable, leave dirty clothes in a designated area to be washed in hot water and bleach. Also, use a respirator with a HEPA filter, and wipe respirators periodically with rubbing or denatured alcohol.
  4. Quarantine affected items by transferring them (in sealed plastic bags) to a clean area with relative humidity below 45 percent, separate from the collection. After the transfer, remove the items from the bags to avoid creating a microenvironment that can foster further mold growth. In the event of a large mold outbreak, it may be necessary to seal off the affected area from the rest of the building to the extent possible.
  5. Dry wet materials in a cool space with good air circulation. The goal is to make the mold inactive, i.e., dry and powdery, to facilitate removal.
  6. Clean the affected items, except active (soft and fuzzy) mold which should be removed only by aconservator using a vacuum aspirator to avoid further embedding. Remove inactive (dry and powdery)mold residue outdoors whenever possible. If this is not possible, close off the affected room and remove the mold using either a fume hood with a filter ( to trap the mold) or a fan that can blow contaminated air out a window. Also use a vacuum with a HEPA filter to contain the mold spores or, alternatively, a wet-dry commercial-strength vacuum with the tank filled with a solution of a diluted fungicide, such as Lysol. Be sure to wear protective gear.
  7. Dry and thoroughly clean the room(s) where the mold outbreak occurred. This can be done by in-house staff or by a company that provides dehumidification and/or cleaning services. Shelves and floors should be cleaned with a wet-dry vacuum filled with a fungicide solution such as Lysol, and then wiped down with Lysol or a similar solution. Make sure that HVAC system components (heat-exchange coils, ductwork, etc.) are cleaned and disinfected, particularly if they may have caused the problem.
  8. Return materials to the affected area, but only after a thorough cleaning and dealing with the cause of the mold outbreak.
  9. Continue to monitor conditions in order to avoid additional mold growth. Measure temperature and relative humidity daily; check problem areas frequently; keep storage collection areas clean; clean floors with a HEPA filter vacuum; prohibit live plants in collection storage or use areas; quarantine acquisitions for a few days; avoid storing braille volumes in potentially damp areas or in locations prone to water accidents; ensure regular building maintenance to reduce the chance of water emergencies; regularly inspect and clean the HVAC system; and change air filters frequently.
  10. Prepare a disaster plan.

Dealing with a Major Outbreak.

If a large portion of the collection is affected by a mold outbreak, if dangerous species of mold are present, or if the HVAC system and the building itself are also infected, it will be necessary to obtain outside assistance. Above all, any infected building must be determined safe for staff occupancy. This determination can be provided by companies specializing in indoor air quality. Several disaster recovery companies specialize in building dehumidification and cleaning, and most will also clean surface mold off collections.

Should fumigation of the affected area be required, fumigants should not be used directly on or in the presence of collections unless there are no other options. Fumigation should always be done by a licensed professional. A conservation or preservation professional can furnish advice on choosing a service provider.


Spores, active or dormant, are everywhere. Although it is impossible to get rid of all spores, mold growth can be controlled. Most important is maintaining relative humidity at 45-50 percent or lower and maintaining a temperature no higher than 70 F. Meticulous house-cleaning and attentiveness to mold conditions are also important. In the event of accidents, dry wet braille volumes and/or remove them from the collection immediately. Similarly, in the event of mold infestation, isolate, dry, and clean the affected materials.

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Posted on 2010-11-12