Mould spores can settle anywhere, and spread in a matter of hours. If volumes, shelves of books or whole archives are attacked by moulds, it is necessary to restore them at great expense, or even destroy them. Mould can also be harmful to health: contact allergies or respiratory infections develop when employees have contact with contaminated archives. Gamma irradiation eliminates obstinate moulds safely, fast, and completely. The materials are totally radiation-free after treatment.