They say that green is the color humans are most sensitive to, owing to our long history of having to tell different green plants apart for survival. Perhaps it is for this reason that dyeing things green using natural dyes has often been somewhat of a let down. Many of these natural dyes are what is known as “fugitive”- meaning they fade, change, or simply disappear over time. In the 1800s when a process for making brilliant green pigments and dyes came along, people were all too eager to jump on the chance to have belongings of vibrant green in their possession. Everything from wallpapers to clothing to paint to books was tinted using this new process. Sadly, the method in question relied on copper acetoarsenite, a pigment made from deadly arsenic. Now, a passionate conservator has made it a mission to test old books for arsenic and to educate the public on the dangers of these beautiful volumes.

1860s Daisy wallpaper by William Morris
William Morris “Daisy” wallpaper pattern, first designed and printed in the 1860s. Morris was known to use arsenic in his brilliant wallpapers. Via: LA County Museum of Art

The quest began in 2019 when book conservator, Dr. Melissa Tedone, was asked by the Winterthur Museum Garden and Library to remove a waxy substance from the intensely-green cover of the 1857 book, Rustic Adornments for Homes of Taste. The cover is bright green with embossed gold accents and in attempting to clean it Tedone found that no matter how gentle the pressure, tiny flakes of the cover color kept flaking off. It was then that she wondered if the book had been colored with a strong pigment, not a dye, that might explain its poor adhesion to the book board underneath.

From there Tedone decided to find out if the green pigment could actually be arsenic-based. After having it tested it was indeed arsenic green (or what is also commonly called emerald green). From there Tedone contemplated how many other books in the Winterthur collection could have arsenic green covers. Of the hundreds in the collection 9 of the tested volumes were positive for arsenic. This prompted Tedone to test more books from other sources.

19th century drawing of hands damaged by arsenic green
19th century drawing of hands damaged by arsenic green. Via: Annals of Public Hygiene and Forensic Medicine/Wellcome Collection

Along with Dr. Rosie Greyburn, who did the chemical testing, they found many books in The Library Company of Philadelphia’s collection that tested positive for arsenic. These volumes are now kept separate from the rest of the books. The pair also tested a $15 vintage book from a local bookshop and it, too, contained arsenic on the cover.

There are no FDA guidelines on the amount of arsenic that is deemed acceptable to handle, eat, or inhale. But, fragile antique and vintage books provide possible contamination since they are handled sometimes with bare hands, which if not washed properly can lead to arsenic ingestion. But, even just skin contact can cause a variety of health problems.

1886 color chart showing different greens
Other names for arsenic green included French green, emerald green, Paris green, parrot green, Imperial green, king’s green, meadow green, Swedish green, and Vienna green. Via: Internet Archive

There’s also the matter of inhalation since the flaking pigments can leave particles of arsenic on surfaces and in the air. The best current safety practice, if these books must be handled, is to wear nitrile gloves and then wash your hands right after removing the gloves. Known arsenic books are to be handled on hard surfaces that can be washed down to avoid accidental contamination. And, the use of an air-removing ventilation system is ideal, too. While the covers hold the most threat to those who handle these books, arsenic compounds were sometimes also used inside books to create vivid, color illustration plates.

There are many books out there that contain this dangerous pigment, unknown to those who handle them. It was once thought that the arsenic green book covers were somewhat rare, but these new findings show that from the most pristine libraries to the local used book store- these volumes are numerous, if not always known.

1835 ornithology book containing arsenic green illustrations
1835 ornithology book containing arsenic green illustrations. Via: Biodiversity Heritage Library/Flickr

These pigments were used from the late 1700s into the end of the Victorian era, just before 1900. They were extremely popular in England, Europe, and in the US since this color was very resistant to fading. This is why many examples of arsenic green are still so vibrant today. Despite their popularity little is known about the production process. Studying sources from the time on bookbinding can be difficult since the colors and techniques were closely-guarded industry secrets, adding a layer of complexity to the current scholarship of these poisonous books.

Tedone is working on devising a better, more comprehensive handling protocol for these tomes. And, some institutions have begun to keep known arsenic books in plastic bags to avoid particulate contamination. While these are helpful, there is the problem of identifying these books, as there are many more out there, including many in private collections without access to scholarly methods.

book on the Crystal Palace pigmented with arsenic
Cover of the 1852 book, History and Description of the Crystal Palace, with a stunning arsenic green cover with gold detailing. Via: Winterthur Poison Book Project

Tedone has created the Poison Book Project to help educate people on the dangers and has also devised a color-chart bookmark to help people to identify if their books might contain arsenic, as the colors achieved by this chemical were very particular.