In this episode we explore a truly unexpected heritage-risk story: the Poison Book Project, where conservators discovered that beautiful emerald-green book cloths from the 19th century were hiding arsenic-based pigments. We trace how a routine conservation observation at Winterthur led to global cataloguing, how the chemistry works, how libraries are responding—and what this means for the next time you pick up a vintage book. If you thought books were safe, think again. Tease alert: we’ll also share the hopeful side of how knowledge safeguards our cultural heritage. The internet says it’s true. Then we chat with Keynote Speaker, Leadership Trainer and Musician, Jason LeVasseur.

Years ago, wallpaper makers in Victorian homes were using brilliant emerald greens to adorn parlours and dining rooms. One infamous book in 1874, Shadows from the Walls of Death by Robert C. Kedzie, contained 86 wallpaper samples laden with arsenic-based pigments, because the cheap brilliant greens and yellows used in decorative papers were literally toxic. That tale had a flair of gothic horror—but the underlying chemistry was real: arsenic compounds, flaking pigment dust, unsuspecting families. The aesthetic of colour had a hidden cost.

Meanwhile, the industrial revolution and mass-publishing boom between about 1840 and 1890 transformed book production. Leather bindings gave way to cheaper cloth bindings, bookcloths dyed in vivid colours to be eye-catching in shop windows. Publishers and binders were racing for marketplace appeal, and vibrant pigments—emerald-green, chrome-yellow, vermillion—entered the palette. Some of those pigments, as it turns out, were chemically dangerous.

Enter the Poison Book Project. Launched by the Winterthur Museum, Garden & Library and the University of Delaware in the United States, this initiative set out to identify and catalogue historic books whose bindings or cloth covers used pigments containing toxic heavy metals. The project’s startling finding: some books from the Victorian era, ordinary-looking on a shelf, are in effect “poison books”.

Let’s dig a little deeper into how this all came to light. In 2019 the project’s story begins with conservators at Winterthur noticing something odd. When lab head Rosie Grayburn and conservation scientist Melissa Tedone examined a book titled Rustic Adornments for Homes and Taste (1857) they found fragments of green pigment flaking away from the cloth cover. Under a microscope the fibrous cloth binding had pigment-dust that, when analysed with x-ray fluorescence (XRF), revealed copper and arsenic. They realized that a pigment known as “Paris green” (also called emerald green) had been used in bookcloth—and Paris green contains copper(II) acetoarsenite, an arsenic compound. Paris green had been used widely in wallpapers, fabrics, paints—but its use in book bindings was unexpected and posed risks.

The project determined that the dust from flaking pigment could become airborne, cling to surfaces near a book, and thus pose a hazard particularly to frequent handlers—librarians, curators, researchers. One article put it bluntly: “These green books are poisonous—and one may be on a shelf near you.” By April 2022 the project had identified 88 books containing Paris green pigment, of which more than 70 used the pigment in their bookcloths; by September 2022 the count exceeded 101 books. The fact that a book designed for reading and display could hide such a hazard is exactly the kind of story we live for.

Now, what does the Poison Book Project actually do? On their website the project offers a searchable Arsenical Books Database, a flowchart for identifying suspect volumes, guides for safer handling and storage, and “Is My Book Arsenical?” questionnaires for librarians and collectors. It is as much a safety-initiative as a historical curiosity.

Here’s a question: why did binders choose pigments like Paris green? The answer lies in the aesthetic and commercial demands of the time. In the mid-19th century, coloured bookcloth was a flashy selling point. Consumers wanted attractive books that looked as good on the shelf as the stories inside. Book-manufacturing firms turned to dyed cloth to reduce costs and appeal to buyers. Pigments like Paris green offered brilliant hues previously reserved for fine arts. But the trade-off was chemical: arsenic-bearing pigment was cheaper, vivid—but hazardous.

Let’s step back into the broader context. The story of art and industrial-chemistry is full of examples where beauty came with risk. Think of the notorious “Scheele’s green” in wallpaper, cobalt greens, even radium in watch-dials. The late 19th century aesthetic of “luxury for all” meant that many mass-produced items used pigments and compounds not fully evaluated for long-term safety. In libraries, the Poison Book Project sits at the intersection of conservation science, chemistry, visual culture and archival history.

As the project has unfolded, institutional responses have ranged from caution to full cataloguing: when a library learns it has a book listed in the database, handling protocols may require gloves, sealed shelving, or restricted access. The goal isn’t destruction of historic volumes, but safe stewardship. The project team specifically notes: the books “are not meant to be destroyed but rather kept in controlled conditions.” The project’s promotional material even includes bookmarks that show an emerald-green bookcloth sample and a warning: “This binding contains arsenic.” Those bookmarks have been sent to libraries in 49 US states and 19 countries. So your university library may have them.

Whether you’re a collector, researcher, or casual bibliophile, the idea that colour and fashion in book production could literally poison you is arresting. One Victorian-era binding using Paris green might release invisible arsenic dust onto your hands or nearby surfaces. The project emphasises the dust is invisible to the naked eye but can irritate eyes, nose, throat and might cause dizziness or nausea in extreme cases. Not every green-covered book is dangerous—many were never treated with arsenic pigments—but the risk exists and is real.

Now let’s dive into some specific stories. One came from the Library Company of Philadelphia where an early investigation found 28 books bound in suspect cloth. Another more dramatic case: a rare book at a British library in Leeds was found in 2022 to be laced with arsenic—news coverage flagged the volume as a “rare book laced with deadly arsenic.” The project also identified not only arsenic but other toxic heavy-metal pigments: chrome yellow (lead chromate) and vermillion (mercury sulfide). The presence of these pigments underscores that the risk was broader than one pigment.

When I first learned about this project I was struck by the layered irony: books are supposed to enlighten, uplift, preserve knowledge—and here some volumes quietly harbour poison. It kind of reminds of a Faustian Deal. You know, you gain something – that being knowledge – but at a deadly price. The scholar handling a rare book might think about its historical provenance, binding, typographical history—but not necessarily about whether the green cloth cover is shedding arsenic dust across their gloves.

What’s more: the Poison Book Project isn’t just about identifying books; it’s about communicating safe practices for institutions large and small. The team publishes webinars, runs presentations for conservators, and offers guidelines for safe handling and storage for “small and mid-sized institutions.”

Because yes, a major national collection might have conservation labs and sealed cases—but a local public library might not.

We pick up our story now with the people driving it. At the heart of the Poison Book Project are Melissa Tedone and Rosie Grayburn. Melissa was working as head of library materials conservation at Winterthur when the green-book clue emerged. Rosie is head of the Scientific Research & Analysis lab at Winterthur and an Associate Professor affiliated with the Winterthur/University of Delaware Program in Art Conservation. They clicked into gear the moment they identified arsenic in a bookcloth sample. From that moment the question became: how many other volumes are there, what risks do they pose, and how do we handle them safely?

The process is technical. First, visual assessment: conservators look for green-cloth bindings of certain periods (roughly 1840-1890), cloth that shows flaking or dust, bright emerald-green hues typical of Paris green pigment. Then, nondestructive testing: using X-ray fluorescence (XRF) spectrometry to detect elements like copper and arsenic. In complex cases, destructive testing may involve Raman spectroscopy or sending a tiny sample to a soil-testing lab. Once a book tests positive, it is listed in the Arsenical Books Database. Libraries and archives cross-check their holdings against this database. On the website the project offers flowcharts titled “Is My Book Arsenical?” and provides safer-handling tips: for example, storing suspect volumes in sealed boxes, using gloves, restricting access. Today the project has identified hundreds of suspect volumes—in May 2024 the site noted “300+ ‘poison books’ and counting”. That number illustrates the hidden magnitude of the issue.

One of the evocative details: the pigment Paris green itself. Introduced in about 1814 and mass-used mid-19th century for wallpaper, fabrics and paints, it contains copper and arsenic; it produces a vivid emerald hue. But over time the pigment is chemically unstable, prone to flake or degrade, and becomes dust. That flake dust is the hazard.

The fact that bookcloth uses starch, sizing, pigments, glue—materials that degrade—is relevant: the cloth holding the pigment can decay, releasing the dust more easily. The publishers may not have expected long-term hazards—they were chasing colour and market share.

There’s also a social/historical dimension: mass-publishing meant that book ownership was no longer elite; more people owned books with flashy coloured cloth. Yet the binders and publishers likely had little awareness of chemical hazard; occupational health standards were limited. So a normal modern library shelf may include a volume whose binding hides a chemical hazard that simply wasn’t comprehended at the time of manufacture.

Another interesting twist: collectors and rare-book dealers have responded. When a book comes up for sale with bright green cloth from the Victorian era, savvy dealers are now checking for the pigment and sometimes selling it as a “poison book” curiosity—but also issuing warnings. Institutions are rethinking how they access, display and handle these volumes. For example: should the binding be replaced, or boxed and restricted? The project emphasises that destruction is not the goal—the goal is informed stewardship.

Let’s consider the irony and hope: on one hand you have a book that can technically endanger the reader or handler; on the other hand, the project opens up new research pathways into book history, pigment usage, binding materials, manufacturing practices and conservation science. By tracking which books used dangerous pigments and why, librarians and conservators gain deeper insight into the material culture of books—not just what’s inside the pages, but how the physical object itself was made and the long-term implications for conservation.

In effect, the Poison Book Project has become a lens for re-evaluating how we think about books—not only as carriers of texts, but as complex objects with material histories. It prompts questions: What other hidden hazards might old books hold? Ink with heavy metals, adhesives with formaldehyde, leather with arsenic tanning agents? The field of bibliotoxicology (yes, that’s a word) is emerging. And the silver lining: awareness means safer libraries, better policies, informed collectors—and the preservation of heritage volumes that might otherwise be lost or mishandled.

Let’s bring in some specific case examples. In one published paper, “Arsenic and Old Bookcloth: Identification and Safer Use of Emerald Green Victorian-Era Cloth Case Bindings,” Melissa Tedone describes how a particular binding from 1857 tested positive for copper and arsenic and how the institution responded by sealing the book in a bag and restricting access. That example opened the door to other institutions checking their green-cloth holdings. The result: libraries worldwide now have bookmarks or labels to mark suspect volumes, training protocols for staff, and inter-institutional sharing of data.

For you listening at home: next time you’re in an old library, with tall stacks and vintage bindings, maybe glance at that emerald-green cloth cover, know it might be more than just attractive. It might carry a piece of conservation history, chemistry history—and a cautionary tale.

Now, what does this mean for the reader, the librarian, the collector? For public libraries with large circulating collections, the risk is low for the general public reading a book once or occasionally. But for staff who handle dozens of books a day, for rare-book rooms where bindings are exposed, the risk is higher. The project recommends sealed housing, gloves, drop cloths, HEPA filtration in extreme cases—and “don’t eat over the book.” Since the dust might settle on surfaces. The moral here isn’t to panic—but to recognise that objects we take for granted may have hidden dimensions.

And finally: we reach the hopeful takeaway. The material history of books has often focused on the text, the libraries, the publishing history. The Poison Book Project adds a new layer: the chemistry, the binding material, the pigment, the conservation implications. It shows that heritage institutions can respond proactively to unseen hazards, embrace science, collaborate across departments (conservators, chemists, librarians) and preserve collections in a safer way. It is a model for how we treat historical artifacts in general.

So when you close the cover of a beautiful old binding, you might recall the story of the Poison Book Project, the emerald-green cloth that looked like a promise—and turned out to hide arsenic. The internet says it’s true.

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