Fungal colonization is one of the main causes of deterioration of our paper based heritage. Emergency situations such as floods are a very favorable scenario for the development of fungi, if the objects are not dried in a short time. Fungi decompose paper through the excretion of enzymes and organic acids, leading to a gradual loss of mechanical strength on the paper. These organisms also excrete colored compounds that interfere with the reading of documents and works of art. In addition, the handling of documents contaminated by fungi poses a serious health risk because of the pathogenic / toxinogenic character of many of these microorganisms. It is important that the collections affected by fungi are analyzed by specialists. At NEON we have specialists in this area, contact us.