“Schweinfurt green” was particularly popular in the 19th century. But it is a paint that contained arsenic and is now a problem for many libraries.

The toxic green color, the so-called “Schweinfurt green”, gave a bright shade used by great artists such as Monet and Van Gogh. This color was also common in 19th century book editions. But due to the fact that it contains arsenic, which is dangerous to health, libraries are now being asked to take action.

An issue that has been around for a while

The problem with books that have this dangerous color has been discussed for a long time in expert circles. It recently attracted media attention as well, when the library of the University of Bielefeld decided in early February to preemptively stop lending and using around 60,000 19th-century books and periodicals. The reason was that the arsenic present in these books is toxic and can cause cancer – hence it was deemed necessary to stop lending such books, until the books were checked more specifically.

The decision to check their books was also made by other university libraries, such as Kiel and Duisburg among others – as well as the library of the University of Dusseldorf, which was already closed for a few days in order to remove some potentially dangerous books .

“You better not lick the books”

So can reading such a book prove to be… dangerous for the reader’s life?

The German Library Association (dbv) was reassuring: after the first checks it was found that with the correct use of the books there is no significant threat either to the readers or to the employees of the respective library. “Licking such a book is definitely not a good idea, but nobody does that,” says Reinhard Altenhaner, vice president of dbv. Anyone who uses the books carefully will be able to continue working with them without any risk.

However, as further investigations show, the issue is not therefore considered to have expired. Because each library is different from the other and everyone uses the books differently, as dbv explains in a statement. How many books from the time period in question are there in the library? Is there free access to them or can someone borrow them already? Therefore, it is up to “each institution to assess the risk and possibly take preventive measures if deemed necessary”.

At the end of 2023 the Association had published a guide, which it compiled in collaboration with experts from the Technical University of Cologne and the university libraries of Bonn and Kiel. The basic idea was that in the light of modern workplace safety provisions, libraries should be careful with old books, “filter out” as much as possible those most likely to contain arsenic, and decide on a case-by-case basis what they will do.

The green that gave color to a gray world

However, this problem is not new. “What surprises me is that there hasn’t been this reflection in libraries for a long time,” says Andrea Renate Pataki-Hood, who was involved in writing the guide as a professor at the Institute for Restoration and Conservation Sciences in Cologne. She herself has been working since 2020 around the issue of versions containing arsenic – and the problem with “Schweinfurt green” was already known.

In the 19th century the synthetic pigment was used in tapestries, dresses, murals and paintings – as well as book publishing. Paint manufacturer Wilhelm Zatler had manufactured the color industrially in Schweinfurt, a town in northern Bavaria, and the color became sought after because in the rather gray world of the 19th century, bright colors were more reserved for members of the upper class – and the color of Zatler was available to many people. Finally, at the end of the 19th century this color was banned in the German Empire.

More careful use is key

At the Berlin State Library, which has one of the largest collections of books from the 19th century in the whole of Germany and of which Reinhard Altenhaner is a permanent representative, measures have recently been taken to protect staff and visitors. As the expert explains, there is no question of systematically checking each individual book.

This is because the books from the 19th century are very numerous: the library has over a million publications from that time. Examining all of these books would be extremely difficult, so “one has to think about whether it’s worth it, given the potential risk,” Altenhaner explains.

Until now, it is completely unknown how many versions of the era contain arsenic – and thus how great the risk is in the worst case. “This is something that still remains to be clarified,” adds Altenhaner, who doesn’t see hysterical reactions as appropriate: “The amounts in the dust or in the books are not large, according to what we have found so far. That is why we believe that by following certain rules there is no risk”, he explains.

The appropriate measures are many and varied
Depending on how masculine a version is, various measures can be useful, from wearing gloves to goggles, a mask, or even a protective suit. Berlin’s state library is also considering setting up a separate area for dealing with books that may contain arsenic.

However, many of these books can be read without touching them at all – and therefore without the slightest risk – because a large part of the library’s collection is also available digitally: “This is something that we should and are going to promote targeted “, Altenhaner concludes.

Edited by: Giorgos Passas