Deadly Tomes
In Umberto Eco's novel The Name of the Rose, one of the key elements is a book laced with poison. The fictional book was deliberately treated that way because the abbot believed that the subject matter was so objectionable that anyone who dared to read them deserved to die.
However, there are an astonishing number of actual antique books that contain dangerous toxins -- but they are far more modern in origin, and the presence of toxins is the result of the printers not understanding the danger of the chemicals they were using in their bindings and spot colors in the text. Arsenic in particular was a very popular -- and deadly -- element of pigments in the Victorian Era, particularly the brilliant green that was popularly known as Paris Green. But there were a number of other chemicals used as dyestuffs and pigments in that era that pose significant, long-lasting threat to health.
Fortunately these books are not overly common -- most of them are over a century old now, and not apt to be sitting on the shelves of any random public library. However, it's quite possible to find them in rare book collections and archives in scholarly institutions, often sitting right alongside harmless ones.
As a result, librarians and library associations are working out procedures for dealing with these books. Some of them are typical rules for a library, like "no eating or drinking," and wearing protective gloves is a common requirement in rare book rooms and archives, especially when dealing with fragile older items (although it's usually to protect the books from dirt and oils in the skin). Others, such as warning researchers not to touch their faces while working with books that contain toxins (which may not do much good, because a lot of face touches are unconscious, and an untrained person not only is unaware of them, but may actively deny them until shown video evidence) and having researchers handle them via a sealed glove box in the case of books with toxins particularly apt to flake and get in the air, where they can be inhaled, are specific to this type of problem.
But the most important part of protection really seems to be identifying them and removing them from the general collection so that random patrons aren't apt to come across them and handle them dangerously while browsing the shelves. Also, particularly with those that involve substances that tend to crumble and be transferred to other objects, including neighboring books, shelves, carpets, and users' clothes and hands, isolating them protects the rest of the library and its patrons from the risks of cross-contamination via otherwise innocuous objects.
However, there are an astonishing number of actual antique books that contain dangerous toxins -- but they are far more modern in origin, and the presence of toxins is the result of the printers not understanding the danger of the chemicals they were using in their bindings and spot colors in the text. Arsenic in particular was a very popular -- and deadly -- element of pigments in the Victorian Era, particularly the brilliant green that was popularly known as Paris Green. But there were a number of other chemicals used as dyestuffs and pigments in that era that pose significant, long-lasting threat to health.
Fortunately these books are not overly common -- most of them are over a century old now, and not apt to be sitting on the shelves of any random public library. However, it's quite possible to find them in rare book collections and archives in scholarly institutions, often sitting right alongside harmless ones.
As a result, librarians and library associations are working out procedures for dealing with these books. Some of them are typical rules for a library, like "no eating or drinking," and wearing protective gloves is a common requirement in rare book rooms and archives, especially when dealing with fragile older items (although it's usually to protect the books from dirt and oils in the skin). Others, such as warning researchers not to touch their faces while working with books that contain toxins (which may not do much good, because a lot of face touches are unconscious, and an untrained person not only is unaware of them, but may actively deny them until shown video evidence) and having researchers handle them via a sealed glove box in the case of books with toxins particularly apt to flake and get in the air, where they can be inhaled, are specific to this type of problem.
But the most important part of protection really seems to be identifying them and removing them from the general collection so that random patrons aren't apt to come across them and handle them dangerously while browsing the shelves. Also, particularly with those that involve substances that tend to crumble and be transferred to other objects, including neighboring books, shelves, carpets, and users' clothes and hands, isolating them protects the rest of the library and its patrons from the risks of cross-contamination via otherwise innocuous objects.