Arsenic Archives: University of Florida Smathers Libraries Test for Books with Toxic Dye  

In The Baldwin’s Library of Historical Children’s Literature, you are bound to find a plethora of vividly colored books including ones with bright green details. But danger lurks amongst those children’s stories.

The University of Florida George A. Smathers Libraries is an institution contributing to The Poison Book Project initiative at the University of Delaware Winterthur Library. The project identifies books whose bindings may contain the dye Emerald Green, which is made of arsenic, and adds them to a national database of books that contain arsenic-based color. According to National Organization of Oceanic and Atmospheric Administration, (NOAA), its toxicity comes from copper acetoarsenite, which is dangerous if inhaled or ingested. 

Copper acetoarsenite was popularized because of its vibrant green color. As a byproduct of the industrial revolution, bookbinders chose to begin binding in textiles as opposed to leather, since it was cheaper, faster, and could reach more social classes, according to Katie Smith, the Smathers book and paper conservator. 

Emerald Green’s use is mostly contained from the mid-18th century to early 19th century where it can be found in book bindings and overlays; it was important to search the collections for any contaminated books. The Smathers collection houses many titles from the arsenic time period, specifically 1837-1877, Fletcher Durant, former head of conservation and preservation, said.  

Researches look at a laptop

The Winterthur Library sent out a list of books to institutions all over the country that conservators had found contained Emerald Green. In 2022, Katie Smith used that list to pull about 15 titles in the Special Collections of Smathers. Six of those books came back positive for the dye. After this discovery, Durant created an internship for a graduate student from the historic preservation program at UF. 

Emma Ramseyer, a graduate student at UF, went book by book with Durant to identify titles that could contain the dye. They used a bookmark created by the Poison Book Project which contains five shades of green that can be compared to potentially toxic book bindings. During the search, Durant and Ramseyer had to wear KN-95 masks and nitrile gloves to handle the books.

“As long as they have been in the UF libraries I believe they’ve always been in special collections,” Durant said; the books have never been public-facing for the UF community. Researchers and students now need to request access to view them in person and use proper protection, such as gloves, when handling the books. Smith plans to house all the titles in sealed polyethylene bags, inside boxes. The boxes will have caution labels advising the user on how to handle them. In addition to this, the books will be taken out of the stacks in Smathers and moved to the Auxiliary Library Facility for added caution. Eventually, all titles will be digitized for easier access.  

After the internship concluded, Durant and his team were left with 121 books to test for copper acetoarsenite. On July 11, in Smathers’ first-floor conference room, Fletcher Durant and Katie Smith went to work confirming books containing dangerous dye. 

Smathers brought in Andrea Torvinen, the collections manager at the Florida Museum of Natural History, and Nicolas Delsol, a postdoctoral researcher at the Florida Museum of Natural History to scan the books with an x-ray fluorescence machine.  

Torvinen and Delsol are both part of the FMNH ceramic technology lab. They used an XRF machine to measure inorganic elements found in the book covers. The XRF machine uses X-rays which cause elements to fluoresce, and that reaction is then recorded and compared against graphs to determine what element is present. 

 Through this process, the team identified 63 volumes with the arsenic dye in the binding, according to Durant. It took about seven hours to scan all the books. Through this process, the Library removed potentially harmful books and added their data to the Poison Book project database for other institutions to use in the future.  Although the majority of the books have been contained, there are still more stacks to be searched and the project will continue on in Special Collections.