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United States National Library of Medicine National Institutes of Health

Acid-Free Paper for Biomedical Literature

It is well known that the acid used in 19th and 20th century papermaking eventually causes the paper to become brittle and break.  NLM has an extensive program for reformatting brittle biomedical books and journals in order to preserve their content for future users. To lessen the need for such preservation efforts in the future, the NLM Board of Regents policy encourages the publishing industry to use permanent, acid-free paper in the production of biomedical literature.

Alkaline Paper

Since the 1990s, papermaking processes that employ alkaline chemistry have become widely available. Paper so produced is acid-free and available in commercial quantities at competitive prices in most paper grades, and will last for centuries of ordinary library use.  The alkaline papermaking process has been increasingly adopted by paper manufacturers because of technological and economic incentives -- it results in reduced water consumption, facilitates waste treatment and saves energy and materials costs. It is also cleaner and less corrosive to machinery than acid-based papermaking.

Task Force

In 1987 the Library appointed a Permanent Paper Task Force composed of commercial, academic, and professional society publishers, editors, authors, paper manufacturers and distributors, printers, librarians, and preservationists. They employed a variety of means to make publishers and printers aware of the problems of acidic paper use and its solutions: to help authors and editors with their concerns about making their works lasting by using acid-free paper, to alert professional societies to the need for permanence of their publications, and to encourage the application of realistic standards in the making and use of permanent paper. By disseminating information about acid-free paper use, the Permanent Paper Task Force helped to resolve the problem of acidic paper and facilitate the preservation of the printed record in biomedicine and other fields of scholarly endeavor.

Permanent Paper Standards and Acid-Free Notices

Publishers of the biomedical literature are encouraged to ensure that their publications are printed on paper that meets the American national standard, Permanence of Paper for Publications and Documents in Libraries and Archives (ANSI/NISO Z39.48. - 1992 (R2002) or the international standard Information and Documentation - Paper for Documents - Requirements for Permanence (ISO 9706: 1994).

It is also important that the use of permanent paper for a publication be identified by a notice in that publication. Without it, libraries would have to test for the kind of paper used in each publication and may in the future inadvertently apply preservation treatments to publications that do not need them. Guidance for the wording and placement of the acid-free notice in the publication can be found in ANSI/NISO Z39.48 - 1992 (R2002), Permanence of Paper for Publications and Documents in Libraries and Archives, for the United States ( The international standard is ISO 9706: 1994, Paper for Documents - Requirements for Permanence (SC 10). Beginning in 1990, journals indexed in MEDLINE® and Index Medicus® that are printed on acid-free paper and carry a notice to that effect are marked as such in NLM's published journal lists, and in LocatorPlus®, the Library's online catalog.

For further information please contact:

Preservation and Collection Management Section
National Library of Medicine
8600 Rockville Pike
Bethesda, Maryland 20894

Phone: (301) 496-8124
Fax: (301) 435-2922

A complete list of NLM Fact Sheets is available at:
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Or write to:

Office of Communications and Public Liaison
National Library of Medicine
8600 Rockville Pike
Bethesda, Maryland 20894

Phone: (301) 496-6308
Fax: (301) 496-4450

Last reviewed: 02 May 2007
Last updated: 09 November 2007
First published: 27 September 2001
Metadata| Permanence level: Permanent: Stable Content