Most hazardous are living or active fungi (mould). Therefore we have special cabinets for mould infested objects, cleaning them in clean workbenches, with face masks and rubber gloves. Sometimes it is necessary to fight such infestations by gamma-ray and cleaning them after because even the dead spawn causes allergies.
Most common in conservation measures, applied by PAL are cleaning, defending paper from infestation (by mould, dust or pest). During 2011-13 about 11,500 kg of files and books were manually cleaned by PAL (page by page). For safety reasons the cleaning took place in clean workbenches. In some extra cases cleaning was necessary to apply as one first step before deacidification. Then it was a basic cleaning, carried out by vacuum cleaner and focused on binding, endpapers, edge plus first and last pages.
In case of heavy mould infestation and damages of paper manual as well as cleaning by machine are dangerous and we apply gamma-ray treatment in lower doses (lower, because higher doses gamma-ray are cracking cellulose chains leading to further destabilization of paper). Gamma-ray destroys the living spawn structures. During 2011-13 approximately 11,000 kg were treated in a special Institute via PAL. After gamma-ray treatment a mechanical fine cleaning is necessary.