Closed due to suspected arsenic: University library checks books. Arsenic is toxic and carcinogenic.
Not every old book that is colored green contains arsenic. Other dyes could also be contaminated. It is unclear in what concentration the arsenic-contaminated pigments are actually released. Several research projects, including in Cologne and Bonn as well as in Kiel, are currently researching the possible dangers and developing ways of dealing with them. The German Library Association has also addressed the “potentially health-damaging pigment components” in historical holdings.