Poison Book Project

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Emerald green bookcloth on an 1852 imprint. Courtesy, Winterthur Library, Printed Book and Periodical Collection

The Poison Book Project is an interdisciplinary research initiative at Winterthur Museum, Garden & Library and the University of Delaware. This ongoing investigation explores the materiality of Victorian-era publishers’ bindings. Research focuses on identifying potentially toxic pigments used in bookbinding components and how to handle and store potentially toxic collections more safely. For the most current information about the project, please monitor this wiki, which is updated regularly. Project developments are also shared on Instagram and LinkedIn with the hashtags #poisonbookproject and #bibliotoxicology.

Toxic Bookcloth Colorants

Over 50% of the 19th-century, cloth-case bindings analyzed for this project to date contain lead in the bookcloth, across a range of colors. Analysis of a range of bookcloth colors has identified iron, copper, and zinc, which, while technically heavy metals by density, are generally considered not to be toxic. Analysis has also identified the following highly toxic heavy metals: arsenic, chromium, lead, and mercury.

  • Continue reading below for more information on books bound with arsenic-containing emerald green bookcloth.
  • Visit Chrome Yellow Bookcloth for books bound with chromium-based chrome yellow bookcloth.

General Handling Tips for 19th-Century Cloth-Case Bindings

No matter which pigments or dyes may be present, it is best practice to avoid ingesting anything or touching the face while handling 19th-century, cloth-bound books. It is also best practice to wash hands after handling books, especially before eating, drinking, or smoking.

At left, chromium green (chrome yellow + Prussian blue) bookcloth on an 1874 imprint; at right, emerald green bookcloth on an 1850 imprint. Courtesy, WUDPAC Study Collection and private owner.

Emerald Green Bookcloth

In early 2019, analysis of 19th-century, cloth-case publishers’ bindings at Winterthur Library revealed bookcloth colored with “emerald green,” or copper acetoarsenite, an inorganic pigment known to be extremely toxic. This pigment’s popularity in England and the United States during the Victorian era is well documented. While the colorant was known to be widely used in textiles for home decoration and apparel, wallpaper, and toys, its use specifically in bookcloth had not been formally explored. Successful commercial bookcloths were a closely guarded trade secret during the nineteenth century, limiting our current understanding of their materiality and manufacture.

Conservation staff and interns at Winterthur Museum, Garden and Library conducted an initial survey of bookcloth pigments in the library’s circulating and rare book collections, later expanding their data set in cooperation with The Library Company of Philadelphia. Books published between 1837 and 1900, a time-period which aligns with the rising use of commercial bookcloth on publishers' case bindings, were analyzed with X-ray fluorescence (XRF) spectroscopy. When arsenic and copper were detected together, Raman spectroscopy was used to confirm copper acetoarsenite.

The first 200 books tested represented a range of vivid bookcloth colors. Thereafter, only books covered in green cloth were selected for analysis, in order to focus on arsenic and move through the collection more efficiently. Now that analysis of green bindings is complete, other colors of bookcloth continue to be analyzed in stages.

Nearly 350 green cloth bindings in the collections of Winterthur and The Library Company of Philadelphia were analyzed. Two books procured from second-hand booksellers were also included in the testing, and were confirmed to contain emerald green. In total, 39 green cloth bindings were found to contain arsenic. Quantitative analysis performed at the University of Delaware Soil Testing Lab indicated that emerald green bookcloth colorant is extremely friable and offsets a significantly detectable amount of arsenic. Emerald green publishers’ bindings present a health risk to librarians, booksellers, collectors, and researchers, and should be identified, handled, and stored with caution.

Trends in Use of Emerald Green in Bookbindings

Based on the data collected by project researchers and crowd-sourced data from other institutions, the following trends in the use of emerald green bookcloth have been identified:

Composite image showing color variation of emerald green bookcloth on book spines, likely a result of air pollution. Even when the color on the spine has oxidized and browned, the green cloth on the front and back covers remains vividly green. Courtesy, Winterthur Library, Printed Book and Periodical Collection
  • Primarily British and North American imprints
  • Vibrant green bookcloth covering the boards (front and back covers)
  • Vibrant green or faded brownish bookcloth on the spine
  • Gold and blind stamped decoration, often paired with gilt textblock edges
  • Publication dates primarily between 1840s-1860s
  • Variations on a morocco grain pattern are common, although other bookcloth grains have also been identified

Based on the data collected by project researchers, researchers at Northwestern University, and crowd-sourced data from other institutions, the following trends in the use of emerald green bookbinding papers have been identified:

  • Primarily German, French, British, and North American imprints
  • Color that ranges from minty to deep green
  • Papers may be matte or glazed
  • Papers may be plain or printed
  • Publication dates range from 1816 to 1899

We have developed a color swatch bookmark to aid in the visual identification of volumes potentially bound with emerald green components.

Emerald Green Color Swatch Bookmark

PLEASE NOTE: We are still collecting addresses for the bookmark waiting list, but we have depleted our current stock and are working on printing a new supply. Thank you for your patience! (June 2023)

As of June 2023, we have distributed 4,000 bookmarks to 49 of the United States and 25 countries around the world. These bookmarks are intended to raise awareness and to assist with visual identification of bookcloth and bookbinding papers which may be pigmented with copper acetoarsenite (emerald green). Bookmark recipients are encouraged to follow up a tentative identification of emerald green pigment with instrumental analysis, when possible, to confirm or refute the presence of arsenic. To receive a color swatch bookmark, please email reference@winterthur.org and write “Emerald Green Bookmark” in the subject line. Please include the following information in your email:

  • Name
  • Postal address
We will not share your contact information with third parties.

Safe Handling & Storage Tips for Arsenical Books

Avoid opportunities for ingestion, inhalation, or skin contact with emerald green pigment. Avoid eating, drinking, smoking, biting fingernails, or touching the face while handling potentially arsenical bookcloth.

Wear nitrile gloves:

Avoid handling suspected emerald green bookcloth with bare hands. Inorganic arsenic may be absorbed through the skin in small amounts. Additionally, a significant amount of arsenic can offset onto the hands and be inadvertently ingested or inhaled through touching the face or eating/drinking. Handling books with damp or sweaty hands can increase the risk of arsenic offsetting onto the skin.

Wash hands:

Even when using gloves, wash hands thoroughly with soap and water after handling suspected emerald green bookcloth.

Isolate book for storage:

If a book is suspected to be bound in emerald green bookcloth, seal the book in a zip-top, polyethylene baggie to limit handling and contain potentially friable pigment. The bagged book can be shelved as-is, or further housed inside a custom-size box. If high humidity in the storage area is a concern, a small silica packet may be inserted into the bag to help control moisture.

If possible, remove books from of circulating collections:

Winterthur Library has relocated arsenical books from its circulating collection to its rare book collection to prevent these books from being checked out and used in patrons' homes.

Wipe down surfaces:

Handle books bound in emerald green bookcloth on hard surfaces (such as a table), and avoid upholstered surfaces (such as an armchair). After handling, wipe down hard surfaces that have come into contact with the book using a damp, disposable cloth.

For Conservators:

A professional conservator performing a conservation treatment on a book bound in emerald green bookcloth should observe the same precautions as above. In addition, work under a certified chemical fume hood. If a chemical fume hood is not available, a second option is to conduct treatment using a ductless fume hood for particulates with a combination HEPA/charcoal filter. Given the friability of emerald green pigment on bookcloth, mechanical manipulation such as lifting the cloth from its board support can result in spalling of arsenical pigment dust several times higher than the OSHA exposure limit of 10 micrograms inorganic arsenic per cubic meter of air. Be aware that the introduction of wet adhesives could cause arsenic to migrate in greater concentration toward the source of moisture. Contact between copper acetoarsenite and acidic substances can trigger the release of highly toxic arsine gas.

Disposal of Hazardous Waste

Emerald green bookcloth is sufficiently friable that it is likely to offset arsenic onto other surfaces, especially porous surfaces. This offset is invisible to the naked eye, but has been detected through analysis. Disposable cloths used to wipe down surfaces that have come into contact with emerald green bookcloth, as well as nitrile gloves used to handle emerald green books, should be considered contaminated with trace hazardous waste, and should be disposed of accordingly. Institutions and private collectors without access to a hazardous waste disposal stream should contact their city officials for advice about how to dispose of arsenic-contaminated gloves and cloths safely.

Disaster Planning & Response for Arsenical Books

Should a disaster situation arise involving fire or water, the risks associated with arsenical bookcloth increase. These risks can be mitigated with disaster planning and labeling. Consider storing arsenical books together in one storage area which can be clearly labeled for disaster responders, in addition to item-level caution labels on individual enclosures. While proper PPE should always be worn during salvage, make sure the need for PPE when handling arsenical books is emphasized in written disaster plans.

Arsenical Books Database

The Arsenical Books Database contains information about green, mass-produced, 19th-century bookbindings collected from bookmark recipients, as well as more conclusive identification of arsenic by Winterthur and other contributing institutions using instrumental analysis. To contribute data to the project, please read How To Submit Data to the Poison Book Project.


Identification Methods for Emerald Green Bookcloth

X-ray Fluorescence Spectroscopy (XRF)

Portable XRF using a zero background plate has proven efficient and accurate as the primary method for identification of emerald green bookcloth in this study. According to the data collected thus far, emerald green pigment was rarely, if ever, mixed with additional pigments when used as a bookcloth colorant. The qualitative XRF spectra consistently indicate strong peaks for copper and arsenic. We strongly recommend collecting qualitative data (counts/spectra), not quantitative data (ppm or %).

Raman Spectroscopy

When possible, Raman spectroscopy has been used to confirm copper acetoarsenite (emerald green) as the specific molecular compound present in arsenical green bookcloth. At Winterthur, eleven books found to contain copper and arsenic (with XRF) have been confirmed with Raman to contain emerald green.

Polarized Light Microscopy (PLM)

In an effort to explore additional techniques for the reliable identification of emerald green, small, destructive samples of seven green bookcloths were analyzed by polarized light microscopy. Examination in plane- and cross-polarized light conclusively and correctly identified emerald green as the colorant in three of the samples, and found a mixture of Prussian blue and chrome yellow in the other four. Tips and recommendations for sampling, sample preparation, and analysis by PLM were compiled into a document available upon request from mtedone[at]winterthur[dot]org or rgrayburn[at]winterthur[dot]org.

Microchemical Test Kits

The Winterthur research team has tested two microchemical test kits for the detection of arsenic, Millipore and Industrial Test Systems. Both accurately confirmed the presence of arsenic in emerald green bookcloth. However, these tests rely on the creation and measurement of arsine gas, arsenic’s most deadly form, and the amount of arsine gas produced when testing emerald green bookcloth proved higher than the test kit's measurement scale. The test strips also contain other toxic components such as mercury, and each test produces a significant amount (100 mL) of contaminated solvent that must be disposed of properly. Arsenic spot tests should be performed only by persons trained in chemical safety, wearing appropriate PPE, under a certified chemical fume hood, with access to safe disposal for hazardous waste according to state law. Arsenic test kits should under no circumstances be used in the home or general library environment.

Color Swatch Bookmark

The Winterthur research team has developed an emerald green color swatch bookmark that is freely available upon request (see above). The bookmark is not a conclusive means of identifying emerald green, but it can help give a visual indication that, when combined with other context clues such as publication date, may help narrow down whether a book is likely to be bound in arsenical green cloth. The color swatch bookmark offers the means to sort a book collection using visual identification, allowing institutions or private individuals to target the books of greatest concern in their collections and make the most efficient and cost-effective use of a consultant to perform instrumental analysis. For institutions or individuals who cannot afford to contract for follow-up instrumental analysis, the bookmark at least provides some means, albeit imperfect, of estimating risk.

Project Team & Contributors

Lead Conservator: Dr. Melissa Tedone

Lead Scientist: Dr. Rosie Grayburn

Winterthur Team:

Meghan Abercrombie, Winterthur Intern
Clare Breene, Bookmark Request Fulfilment Volunteer
Jane Burslem, Bookmark Request Fulfilment Volunteer
Alison Chew, Winterthur Intern
Philip DePaola, Winterthur Intern
Phoebe Doherty, Bookmark Request Fulfilment Volunteer
Dr. Patricia Elena Gonzales Gil, Visiting Researcher (Winterthur), Professor, Sección Química, Pontificia Universidad Católica del Perú
Emily Guthrie, (former) Winterthur Library Director, and Winterthur Library staff
Layla Huff, Winterthur Intern
Amanei Johnson, Winterthur Intern
Sara Leonowitz, Winterthur Intern
Catherine Matsen, Winterthur Sr. Conservation Scientist
Diane McMinn, Bookmark Request Fulfilment Volunteer
Keith Minsinger, Assistant Registrar, Museum CMS
Jess Ortegon, WUDPAC Fellow
Mina Porell, Winterthur Postgraduate Fellow in Paintings Conservation
Tempe Stewart, Winterthur Intern
Esther Weyer, Winterthur Intern

Bookmark Design:

Karissa Muratore, WUDPAC '20 (v.1)
Gayle Bezerra, Teresa Vivolo, Stephanie Gaster, Winterthur Marketing (v.2)


Michael Gladle, (former) Director; Brandon Calitree; John Verdi, University of Delaware Environmental Health & Safety
Karen Gartley, Research Manager/Program Director, University of Delaware Soil Testing Program
Kirsten Moffitt, Conservator and Materials Analyst, Colonial Williamsburg Foundation

Contributing Institutions and Individuals:

American Antiquarian Society
Boston Athenaeum
Burt Thompson
George A. Smathers Libraries, University of Florida
Middlebury College Special Collections
Mitchel Gundrum & Jane Knoll
Northwestern University Library
Philadelphia Athenaeum
Ronald Smeltzer
University of Delaware, Morris Library
University of Oregon Libraries
The Library Company of Philadelphia
William & Mary Libraries
Winterthur Library

Project Publications & Presentations


Tedone, Melissa, and Rosie Grayburn. Accepted November 27, 2022. "Toxic Tomes: Understanding the Use & Risks of Heavy Metals in 19th-century Bookcloth." Collections: a journal for museum and archives professionals.

Tedone, Melissa, and Rosie Grayburn. 2023. "Arsenic and Old Bookcloth: Identification and Safer Use of Emerald Green Victorian-Era Cloth Case Bindings." Journal of the American Institute for Conservation. Vol. 62, Issue 1.

Tedone, Melissa, and Rosie Grayburn. "Arsenic and Old Bookcloth: The Safe Handling, Treatment, and Storage of Victorian-Era Cloth Case Bindings." Book and Paper Group Annual 39 (2020).

Tedone, Melissa. "Poison Book Project". IIC News in Conservation 77. April-May, 2020. 10-13.

Presentations (click links to access recordings)

Tedone, Melissa. "The Poison Book Project: Heavy Metals in 19th-century Euro-American Bookbinding." Ex Libris Lecture Series. Providence Athenaeum. Providence, RI. March 24, 2023.

Tedone, Melissa. "Heavy Metals and 19th-Century Euro-American Bookcloth Manufacture." Fred Bearman Memorial Lecture. ICON. London, UK. August 25, 2022.

Tedone, Melissa. "If Books Could Kill: Toxic Textiles in 19th-Century EuroAmerican Bookbinding." Material Evidence: Museum at the Fashion Institute of Technology Symposium. Recorded June 28, 2022. Release on YouTube expected November 11, 2022.

Tedone, Melissa. "The Poison Book Project." Preservation Webinar Series, National Library and Information System Authority (NALIS), Trinidad & Tobago. April 27, 2022.

Tedone, Melissa. "The Poison Book Project." Lunchtime lecture series, Philadelphia Athenaeum. April 19, 2022.

Tedone, Melissa. "The Poison Book Project: Arsenic in Victorian-Era, Mass-Produced Bookbindings". Friends of the University of Delaware Library Fall Faculty Lecture. November 16, 2021.

Tedone, Melissa and Rosie Grayburn. "It Ain't Easy Being Green: The Poison Book Project". The Grolier Club. May 11, 2021.

Tedone, Melissa. Toxic Tomes in Context: 19th-century Decorated Cloth Bindings. Objects Up Close series (virtual). Winterthur Museum, Garden & Library. March 16, 2021.

Tedone, Melissa. "Toxic Tomes: A Hidden Hazard in the Victorian Home." Pre-recorded lecture. Virtual Delaware Antiques Show Lecture Series. November 7-14, 2020.

Tedone, Melissa. Arsenic and Old Bookcloth: A Hidden Hazard in Victorian-Era Books. Presentation for Winterthur Collector's Circle Virtual Salon Series. September 2, 2020.

Tedone, Melissa, and Rosie Grayburn. Arsenic and Old Bookcloth: The Safe Handling, Treatment, and Storage of Victorian-Era Cloth Case Bindings. American Institute for Conservation 48th Annual Meeting. June 30, 2020.

Tedone, Melissa, and Rosie Grayburn. Winterthur Poison Book Project. Presented virtually at the ICON Book and Paper Annual General Meeting. June 3, 2020.

Tedone, Melissa, and Rosie Grayburn. Poison Book Project: Analyzing Toxic Pigments in Victorian-Era Bookcloth. Lightning-round presentation at Safety and Cultural Heritage Summit, Smithsonian American Art Museum, Washington DC. October 30, 2019.

Related Scholarship

Knoll, Jane. "Arsenic Pigments in Bookbindings in the Boston Athenæum." Online lecture. Boston Athenaeum. April 21, 2022.

Krol, Wiktoria. 2021. "Rozmowa w zielonym pokoju: zatrute książki" [Conversation in the green room: poison books]. Kolor smierci, odcien grobu czyli 50 odcieni morderczej zieleni [The color of death, the shade of the grave, that is, 50 shades of murderous green]. Krakow: Wydawnictwo IX. 183-192.

Sirmans, Harikleia. "Judging A Book By Its Cover." Textile Tuesday: Toxic Textiles in Libraries. Textile Society of America. April 18, 2023.


Sloan, Marissa. "Beware These Poisonous Books." Discover Magazine. March/April 2023. 17.

Nas Daily. Shorts. "These Books Are Poisonous." December 4, 2022.

Downey-Mavromatis, Arminda. "Toxic tomes, plus what it takes to make this magazine." Chemical & Engineering News. October 31, 2022.

"Leeds: Rare Book Laced with Arsenic Found in Library." BBC News: UK, Leeds & West Yorkshire. October 28, 2022.

Sloan, Marissa. "Victorian-era Books Bound in Emerald Green Are Laced with Arsenic." Discover online. September 19, 2022.

Brower, Justin. "On the Trail of Toxic Tomes." National Geographic Magazine. September 2022. 24.

Parini, Elsie Lynn. "Need a Killer Read? Check Out These Poison Books." Addision County Independent. May 12, 2022.

"The John Oakley Show." Global News. 640AM Toronto. May 4, 2022.

"Researchers at Delaware Museum Warn of Poisonous 19th-Century Books." NBC 10 News. Philadelphia: WCAU. May 2, 2022.

The Poison Book Project. Apple News Today. May 2, 2022. [Clip starts at min. 9:20.]

Brower, Justin. "These green books are poisonous -- and one may be on a shelf near you." National Geographic. April 28, 2022.

"Books That Can Kill." Duo Dive. Vintage & Vinyl. December 15, 2021.

Pogacar, Charlie. “Arsenic and Old Books." Fine Books and Collections Magazine, 19.1, Winter 2021.

Further Reading

"Copper Acetoarsenite." NOAA CAMEO Chemicals version 2.7.1. rev 1. Accessed February 13,2020. https://cameochemicals.noaa.gov/chemical/2981

Gehle, Kim. “Arsenic Toxicity.” Environmental Health and Medicine. Centers for Disease Control and Prevention, Agency for Toxic Substances & Disease Registry, last modified January 15, 2010. https://www.atsdr.cdc.gov/csem/arsenic/cover-page.html

Lundblad, Kristina. 2015. Bound to be modern : publishers' cloth bindings and the material culture of the book, 1840-1914. Trans. Alan Crozier. New Castle, DE : Oak Knoll Press.

Krupp, Andrea. 2008. Bookcloth in England and America, 1823-50. New Castle, DE: Oak Knoll Press; London: British Library; New York: Bibliographical Society of America.

Tomlinson, William, and Richard Masters. 1996. Bookcloth 1823-1980 : a study of early use and the rise of manufacture, Winterbottom's dominance of the trade in Britain and America, production methods and costs, and the identification of qualities and designs. Cheshire, Eng.: D. Tomlinson.

Whorton, James C. 2010. The Arsenic Century: how Victorian Britain was poisoned at home, work, and play. Oxford, New York: Oxford University Press.

Funding Acknowledgments

The project team gratefully acknowledges the following support for the Poison Book Project:

  • Our many generous donors who supported the project during the Do More 24 Delaware fundraising campaign coordinated by the United Way in February, 2020.


Copyright 2023. This article describes conservation procedures and is meant to be used as exchange of technical information among trained cultural heritage conservators, and the procedures described herein should not be performed by anyone who is not a trained professional. Further, any advice, graphics, images, and information contained in this page is presented for general educational and information purposes, and to increase safety awareness in connection with the storage and handling of aged books that may contain toxic chemicals, such as arsenic. The storage, handling, and other safety tips included in this page are suggestions only and have been collected by the Poison Book Project of The Henry Francis du Pont Winterthur Museum, Inc. after consultation with scientists and other experts in the conservation field. None of the content in this page has been subjected to a formal peer review and is not intended to be medical or other expert advice or services, and should not be used in place of consultation with appropriate professionals. The information contained in this page should not be considered exhaustive, and the user should seek the advice of appropriate professionals.

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