Freezing used books helps eliminate pests and mold

Freezing used books is a recognized method for eliminating pests and preventing mold growth. This non-chemical technique is utilized by major institutions, including the Library of Congress and the Smithsonian, to protect paper materials from damage.

A common issue for old books is the presence of booklice, microscopic insects that thrive in damp environments and feed on mold. Sub-zero temperatures kill these insects by causing the fluids in their bodies to crystallize and damage their cells. Freezing also helps manage mold by making spores inactive.

To perform this method safely, books should be placed in a tightly sealed plastic bag to prevent moisture from entering. Experts recommend freezing the item for at least 48 hours. Once removed from the freezer, the book must remain in its sealed bag and reach room temperature gradually to prevent condensation from forming on the pages.