Scientists at the University of St Andrews have developed a new tool to identify books containing toxic emerald green pigment made from arsenic and copper. The device can quickly detect the presence of this pigment, which can cause health issues including eye irritation and serious side effects.
Historically, publishers used these toxic materials in book bindings to achieve a vibrant green color. However, the risk to public health remains low, but prolonged exposure can lead to problems. Many libraries have taken precautions by removing suspect books from circulation or storing them separately.
The new tool uses a unique reflectance pattern to detect the presence of emerald green pigment. It shines different colors of light onto the book and measures the reflected light, creating a “fingerprint” of the pigment. The handheld device can screen books in just a fraction of a second.
Researchers have identified over 100 books containing emerald green pigment using this technology. To ensure public safety, the University of St Andrews stores emerald green books in specialized bags and checks for alternative copies before handling them with special precautions.
The development of this tool is significant not only from a safety perspective but also in terms of accessibility. It allows more books to be made available for users while minimizing the risk associated with toxic materials. A free exhibition exploring this project is currently running at the Wardlaw Museum in St Andrews until July 31st.
Source: https://www.theguardian.com/books/2025/jun/06/tool-to-identify-poisonous-books-developed-by-university-of-st-andrews