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United States National Library of Medicine National Institutes of Health

Fact Sheet
Preservation Program


In response to its mandate to preserve the biomedical literature, the National Library of  Medicine has developed an extensive preservation program.  Elements of the program include:

  • Microfilming brittle serials and monographs
  • Library binding
  • Conservation and book repair
  • Preserving audiovisuals
  • Preserving electronic formats
  • Disaster prevention and recovery
  • Preservation education
  • Permanent paper campaign

Microfilming Program

Condition surveys conducted in 1985 and 2000 indicate that 12% of the volumes in the NLM collection are on acidic paper that has become brittle over time. In 1986, the Library began an ambitious  program of microfilming brittle serials and monographs that are in core medical subjects.  These materials are being filmed at a rate of approximately 5,000 volumes per year.  Initial priority was given to serials indexed in Index Medicus ® and monographs that are in the most fragile condition. At present, priority is being given to serials listed in the Index-Catalogue of the Library of the Surgeon-General's Office.

Because it is assumed that any microfilm produced by NLM will become the master copy for the country, the Library attempts to film the brittle portion of serials in as complete runs as possible.  Volumes missing from the NLM collection and needed for filming are borrowed from other libraries.  Many U.S. and foreign libraries have cooperated in this effort.

To avoid duplication of effort by other libraries, NLM makes records for the titles it has filmed available through its online catalog.  Before deciding to reformat their own brittle materials, libraries should search LocatorPlus (http://locatorplus.gov) to determine whether microfilm is available from NLM.

Within copyright restrictions, the Library permits purchase of microfilm copies of the titles it has filmed.  For order information, consult the NLM Fact Sheet, Microfilm Sales Program.

Library Binding

NLM contractors prepare and bind approximately 32,000 serial and monograph volumes per year.  Preservation staff work closely with the contractors to ensure that preservation quality standards are met.

Conservation and Book Repair

NLM has had a long-standing program for the conservation of valuable materials in its History of Medicine Division collection.  HMD staff manage contracts for off-site conservation services.  In addition, NLM has an on-site lab for simple repair of volumes from the general collection and conservation of more valuable materials.  Treatments include page mending and cleaning, hinge and spine repair, tape removal, replacement of missing pages and construction of protective enclosures.

Preserving Audiovisuals

NLM's Preservation and Collection Management Section works with History of Medicine Division staff to identify audiovisuals that are deteriorating or in formats that are becoming obsolete.  Duplication masters and user copies are produced and the original copies are sent to off-site cold storage. 

Preserving Electronic Formats

One of the biggest challenges libraries face today is the need to develop strategies for preserving materials in electronic form.  The Preservation and Collection Management Section recently surveyed computer files in the general collection to determine the extent to which format deterioration and obsolescence are making it difficult to retrieve the information they contain.  An even more challenging problem is the preservation of online publications.  NLM's National Center for Biotechnology Information (NCBI) has developed PubMed Central, a digital archive of life sciences journal literature (www.pubmedcentral.nih.gov).   In addition, NLM staff have developed a system of permanence ratings to indicate to users whether the location, content, or availability of   NLM's electronic publications is subject to change.  A report on the rating system is available at: www.nlm.nih.gov/pubs/reports/permanence.pdf.   NLM continues to work with other libraries and organizations to resolve the many complex issues related to archiving materials in electronic form.    

Disaster Prevention and Recovery

The Library has developed a comprehensive plan for protecting the collection and salvaging materials should they become damaged by flood or fire.  Staff have been assigned to teams and trained in collection recovery procedures.  An extensive collection of disaster supplies and equipment is kept on hand.

Preservation Education

NLM has issued posters, bookmarks and flyers on a variety of preservation topics. Examples can be seen under NLM Preservation Awareness Materials at www.nlm.nih.gov/psd/pcm/pcm.html).  In addition, the Preservation and Collection Management Section offers staff training in good preservation practices and a reference service for general preservation questions and disaster recovery advice (PRES@NLM.NIH.GOV) .

Permanent Paper Campaign

In 1987, the National Library of Medicine launched a campaign to reduce the amount of acidic paper used in biomedical publications.  (See NLM Fact Sheet Acid-Free Paper for Biomedical Literature.)   Since that time, major changes in the papermaking industry as well as increased awareness on the part of authors and publishers have led to significant increases in the use of alkaline paper.  Studies conducted in 2000 showed that between 1976 and 2000, the proportion of acidic volumes being added to the NLM collection each year declined from 80% to 12%.  Only 1.5% of current issues of Index Medicus titles were on acidic paper. 

 For further information please contact:

Preservation and Collection Management Section
National Library of Medicine
Rm B1E21
8600 Rockville Pike
Bethesda, MD 20894
Phone: (301)496-8124
Fax: (301)435-2922

Email:   PRES@NLM.NIH.GOV

Last updated: 06 January 2004
First published: 01 September 1985
Metadata| Permanence level: Permanent: Stable Content
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