When wear has occurred, you can apply a series of procedures ranging from a simple repair to a complete restoration. Also, in the opinion of Arsenio Sanchez, any library, however small it may seem and by scarce than its resources, can count on a conservation program tailored to their needs, with beneficial results. In short, take care and preserve in the best possible way the books and other files is a work that relates to all persons who are part of a library, from the same staff, who must seek safety measures minimum, up to the user, who must respect the maximum material used, which largely prevents having to go to the restorationa process expensive and laborious and sometimes, when it is too late, fruitless. The restorers are experts who are responsible for recovering as much as possible the damaged works. In Spain, for example, there is the Institute of historic heritage, which is responsible for the restoration of books and manuscripts. How can I to deal with these dangers? More effective precautionary measures include the control of the quality of the air, using chemical filters or wet extractors, or maintaining as far as possible the exterior Windows closed. Another useful measure consists in the storage of copies in protective cases, especially those compounds of materials such as activated carbon, absorb the pollutants. In recent years, are being used in addition specific microclimates that limit the possibilities of proliferation of pests and step controlling the moisture content of the objects. If books end up filling of mushrooms, especially in the case of having come into contact with water, some restaurateurs are advised to freeze them, so that disappear and leaves no sticking. However, if any biological agent has already managed to cause damage, immediate intervention is necessary, avoiding the use of microbicides and insecticides of broad spectrum, causing toxicity and chemical alterations in the treated materials.