# Slow fire > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Slow_fire > Markdown URL: https://mediated.wiki/source/Slow_fire.md > Source: https://en.wikipedia.org/wiki/Slow_fire > Source revision: 1331872532 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Expand German|date=January 2020}} {{short description|Paper embrittlement of a book or document}} thumb|A book printed in 1920 on acid paper that is disintegrating. '''Slow fire''' or '''acid decay''' is a term used in [library and information science](/source/library_and_information_science) to describe [paper](/source/paper) embrittlement resulting from acid decay. The term is taken from the title of [Terry Sanders](/source/Terry_Sanders)'s 1987 film ''Slow Fires: On the preservation of the human record.''{{Cite web |last=Vassot |first=Chloe |date=2019-10-17 |title=The Little-Known 'Slow Fire' That's Destroying All Our Books |url=https://lithub.com/the-little-known-slow-fire-thats-destroying-all-our-books/ |access-date=2025-06-03 |website=Literary Hub |language=en-US}} Solutions to this problem include the use of [acid-free paper](/source/acid-free_paper) stocks, [format shifting](/source/format_shifting) brittle books by microfilming, photocopying or digitization, and a variety of [deacidification](/source/mass_deacidification) techniques. ==History== Much of the early paper made from wood pulp contained significant amounts of [alum](/source/alum), a variety of [aluminium sulfate](/source/aluminium_sulfate) salt that is significantly [acidic](/source/acidic). Alum was added to paper to assist in [sizing](/source/sizing),{{Cite book|title=Essentials of pulping and papermaking|last=Biermann|first=Christopher J/|date=1993|publisher=Academic Press|location=San Diego|isbn=978-0-12-097360-6|oclc=813399142|url-access=registration|url=https://archive.org/details/essentialsofpulp0000bier}} making it somewhat water resistant so that [inks](/source/inks) did not "run" or spread uncontrollably. Early papermakers did not realize that the alum they added liberally to cure almost every problem encountered in making their product would be eventually detrimental.{{cite book |last=Clark |first=James d'A. |title=Pulp Technology and Treatment for Paper |edition=2nd |date=1985 |publisher=Miller Freeman Publications |location=San Francisco |isbn=978-0-87930-164-4}} The [cellulose](/source/cellulose) fibres that make up paper are [hydrolyzed](/source/hydrolyzed) by acid, and the presence of alum eventually degrades the fibres until the [acidic paper](/source/acidic_paper) disintegrates in a process known as ''slow fire''. Documents written on [rag paper](/source/rag_paper) are significantly more stable. The use of non-acidic additives to make paper is becoming more prevalent, and the stability of these papers is less of an issue. Paper made from [mechanical pulp](/source/pulp_mill) contains significant amounts of [lignin](/source/lignin), a major component in wood. In the presence of light and oxygen, lignin reacts to give yellow materials,{{cite journal | last1 = Fabbri | first1 = Claudia | last2 = Bietti | first2 = Massimo | last3 = Lanzalunga | first3 = Osvaldo | year = 2005| title = Generation and Reactivity of Ketyl Radicals with Lignin Related Structures. On the Importance of the Ketyl Pathway in the Photoyellowing of Lignin Containing Pulps and Papers | journal = J. Org. Chem. | volume = 2005 | issue = 70| pages = 2720–2728 | doi = 10.1021/jo047826u | pmid = 15787565 }} which is why [newsprint](/source/newsprint) and other mechanical paper yellows with age. Paper made from [bleached](/source/bleaching_of_wood_pulp) [kraft](/source/kraft_process) or [sulfite](/source/sulfite_process) pulps does not contain significant amounts of lignin and is therefore better suited for books, documents and other applications where whiteness of the paper is essential. Paper made from wood pulp is not necessarily less durable than a rag paper. The aging behaviour of a paper is determined by its manufacture, not the original source of the fibres.{{cite journal | last1 = Erhardt | first1 = D. | last2 = Tumosa | first2 = C. | year = 2005 | title = Chemical Degradation of Cellulose in Paper over 500 years | journal = Restaurator: International Journal for the Preservation of Library and Archival Material | volume = 26 | issue = 3| page = 155 | doi=10.1515/rest.2005.26.3.151| s2cid = 98291111 }} Furthermore, tests sponsored by the [Library of Congress](/source/Library_of_Congress) prove that all paper is at risk of acid decay, because cellulose itself produces [formic](/source/Formic_acid), [acetic](/source/Acetic_acid), [lactic](/source/Lactic_acid) and [oxalic](/source/Oxalic_acid) acids. {{cite web | title = The Deterioration and Preservation of Paper: Some Essential Facts | url = https://www.loc.gov/preservation/care/deterioratebrochure.html | access-date = 7 January 2015 | publisher = [Library of Congress](/source/Library_of_Congress) | quote = Research by the Library of Congress has demonstrated that cellulose itself generates acids as it ages, including formic, acetic, lactic, and oxalic acids | ref = refDeteriorationOfPaper | archive-url = https://web.archive.org/web/20150120175215/http://www.loc.gov/preservation/care/deterioratebrochure.html | archive-date = 20 January 2015 | url-status=live }} ==See also== * [Acidic paper](/source/Acidic_paper) * [Acid-free paper](/source/Acid-free_paper) * [Double Fold](/source/Double_Fold) * [Wood-pulp paper](/source/Wood-pulp_paper) * [Preservation (library and archive)](/source/Preservation_(library_and_archive)) ==References== {{reflist}} ==External links== * [http://www.ceserp.com/cp-jour/index.php?journal=ijls ''International Journal of Library Science ''] * [http://www.clir.org/pubs/film/film.html ''Slow Fires: On the Preservation of the Human Record''] at [CLIR Films](/source/Council_on_Library_and_Information_Resources) * {{IMDb title|0287709|Slow Fires: On the Preservation of the Human Record}} Category:Preservation (library and archival science) Category:Paper data storage Category:Metaphors referring to objects Category:Book terminology Category:Newspaper terminology {{Cultural Conservation-Restoration}} {{Reaction-stub}} --- Adapted from the Wikipedia article [Slow fire](https://en.wikipedia.org/wiki/Slow_fire) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Slow_fire?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.