Ultimo aggiornamento 5 July 2023
The laboratory for the environment studies, for the part of its competence, the construction and functional standards of the archives, libraries and annexed restoration laboratories (environments, equipment and materials), the safety measures (fire-fighting systems, burglar alarms, etc. ), the control and regulation of environmental conditions (temperature, humidity, ventilation, lighting), also in relation to the protection of the health of workers and library users.
Conservation bodies of archival and book assets, located throughout the national territory, can request advice and support from the environmental laboratory in relation to the instrumental techniques for monitoring the climatic conditions of the conservation places and for the management of exceptionally large calamitous events and to deal, according to the most appropriate methods, with the small emergencies that can occur daily or exceptionally in environments used for the conservation of paper material.
The application must be accompanied by form A “request for inspection” and addressed to the Director of the Institute email@example.com.
Museums, libraries, archives, in general all the places that preserve and exhibit cultural heritage (in our case of paper material) must guarantee environmental, structural, usage, anti-crime, fire safety; therefore a whole series of actions must be implemented to protect, preserve and consolidate the “container” against those factors that can affect the conservation of the asset.
The safety of storage/display environments involves checking the following parameters/conditions:
- structural suitability
- air conditioning/treatment
- temperature and humidity
- crowding and management of personnel/visitor flows
- presence of harmful agents (physical, chemical, biological)
- tools to contrast malicious actions (thefts, vandalisms, attacks….etc)
- security project
- Regulatory references and guidelines
The design of safety in buildings constituting “cultural heritage” due to their specific historical-artistic characteristics cannot be faced with a deterministic-prescriptive approach; in the majority they are architectures that in the design phase had not been destined for current use, and date back to periods historically distant from our technological civilization. Added to this is that often the structural and plant engineering interventions to adapt them to current legislation are so invasive as to risk distorting the artistic and historical reality of the building. Therefore, without prejudice to the essential requirements to be met, the designer’s approach must adjust the safety strategy from time to time to specific realities, through a series of risk analyzes and assessments. In particular, it is necessary to take note of all the sensitive areas in terms of safety and find design solutions to resolve situations at risk. Please refer to the sector literature for more details. In general, the main aspects of safety are highlighted below:
- security of accesses and buildings
- prevention of criminal and dangerous behaviour
- security of archival and library material
- management of natural and man-made disasters (step-by-step approach)
- risk assessment (analysis of hazards and natural and anthropic actions)
- prevention (fire alarm systems, ordinary maintenance of all systems, emergency plan, etc.)
The evaluation is aimed at compliance with the rules concerning fire safety for buildings of historical-artistic interest intended for libraries and archives (Presidential Decree June 30, 1995, n. 418; Activities n. 72 of Presidential Decree August 01, 2015) and the safety and health of workers in the workplace (Legislative Decree April 9, 2008 n. 81 and subsequent amendments. mm. and ii.).
The furnishings in the archive and paper cultural heritage conservation rooms must be designed bearing in mind both their function and the characteristics of the building in which they are located, so as to have optimal structural characteristics and in order to make the best use of the available space. It is therefore preferable to have shelves with movable shelves, adaptable to the distance of the archive containers or the various book sizes.
The material of the shelving must be, if possible, hot-painted or galvanized metal to avoid the formation of rust, without protrusions and sharp surfaces; the shelving must have such a width and depth (30-40 cm) to ensure that the documents do not protrude beyond the edges.
The wooden shelving, often present in buildings of historical and artistic value, favor the proliferation of molds and parasites, as well as increase the fire load; therefore, if possible, they should be avoided or at least treated with fire retardant paints and periodic pesticide treatments.
Another element to consider is the capacity of the individual shelves on which the documents/books rest, the guaranteed minimum capacity must be at least 60 kg/m; therefore shelves with reinforcing ribs and no longer than one meter are preferable.
The lowest shelf should always be mounted no closer than 15cm. from the ground to limit the damage connected to possible flooding (but in areas prone to flooding this distance must be at least 50 cm). The upper floor must be at least 50 cm away from any lighting systems. Of course, all the shelves must be suitably fixed to the ground, to the walls or braced, to prevent them from falling and tipping over. The shelves must have lateral shoulders or bookends in order to avoid lateral falls of the material.
The position of the shelves with respect to the exposure of the environment is also fundamental; never leaning in direct contact with the walls, at least 20 cm away to avoid contact with any mould, under windows or vents, under exposed pipes due to the consequent risk of possible flooding or water infiltration. It is necessary to arrange the shelves at least 90 cm from each other to allow the passage of trolleys and to prevent the spread of any fires (if standard ladders are used, the distance between the shelves must be at least 120 cm).
The use of closed shelving (avoid sliding doors) allows you to store documents without having to resort to folders and boxes, however it is important that correct air exchange is ensured in order not to risk the formation of a microclimate harmful to the material preserved. The height of the shelves, when the useful space allows it, is preferable not to exceed 2.15 m. in order to pick up the material without the aid of ladders.
For documentation with particular formats, maps, drawings, it is necessary to prepare special containers and horizontal shelves or chests of drawers of suitable sizes to contain them.
Separate considerations must be made for those furnishings (cases, showcases, showcases, etc…) intended for the protection, conservation and display of paper goods, in museum places. In this case, the design must take into account the specific dimensional and material characteristics of the “property” in question as well as the microclimate suitable for its conservation (temperature values, relative humidity, lighting).
It is necessary to avoid cluttering the archive/book deposit with incongruous objects (packs of blank forms, flags, broken chairs…) especially if flammable.
Excessive exposure to the sun and light in general is in itself an important factor in the deterioration of archival documents and books, since light rays cause rapid and irreversible chemical and chromatic modifications of the paper, inks and colored surfaces (maps, drawings, covers).
All wavelengths of light – visible, infrared and ultraviolet (UV) – accelerate the chemical decomposition of organic materials through oxidation. Ultraviolet, being the factor with the highest energy, is the most harmful. Therefore it is essential to keep the lighting levels under control for monitoring the state of conservation of the “paper”. Light, both natural and artificial, can damage documents: it discolours and yellows them. The damage caused by light is irreversible since the light from fluorescent lamps, like that of the sun, produces ultra-violet rays which are very harmful to documents. Not only that, the light illuminates a surface with the consequent production of heat and heat, in turn, causes ageing.
It is therefore essential and necessary to protect paper material from excessive and prolonged exposure to UV rays.
Some brief and general considerations on artificial light
Lighting levels should be kept as low as practically possible, both in warehouses and in reading and exhibition rooms.
From the point of view of conservation it would be preferable to keep them in the dark, but this is not always possible; We can adopt some simple and effective measures:
- place documents in cardboard folders,
- reduce lighting to a minimum,
- turn off the lights when there is no one in the depots, also through the design of a lighting system with sensors that will automatically turn off the light in the absence of personnel.
Some technical design data
There are various types of lighting, incandescent lamps, tungsten halogen lamps, fluorescent lamps, etc…; although fluorescent light has a high ultraviolet radiation content, it is usually installed in libraries because it develops less heat and is more economical to operate
The recommended lighting levels (IFLA 2004) are referred to as a general indication:
- 200-300 lux are acceptable levels for reading rooms,
- 50-200 lux is sufficient in warehouses. However, to achieve these levels it would be necessary to completely exclude natural light and rely totally on artificial lighting.
- Light sources with ultraviolet radiation emissions exceeding 75 microwatts per lumen require filters.
- At exhibitions, the level of light hitting the surface of exhibits should be kept low, no more than 50-70 lux, for eight hours a day for a maximum duration of 60-90 days, they are often recommended for photosensitive materials , such as colored papers, newspaper, and certain bindings (such as cloth bindings), and media such as manuscript inks and watercolours.
It is necessary to measure and record the levels of light and ultraviolet radiation at different times of the year, since the values change with the seasons.
In addition to climatic and location data, the other factors that influence the internal illuminance of places of conservation (libraries, museums, warehouses) are the shape and positioning of the openings in the facades, the shading by other surrounding buildings, the type of shielding, the constituent material and its operating model.
The control of natural lighting is important not only to guarantee an adequate quality of light inside the building, but also to avoid the inconveniences due to direct solar radiation, which in fact contains infrared rays (cause of raising the temperature and increasing the thermal load) and ultraviolet rays (cause of chemical reactions with alteration of the properties and colors of paper documents, finishes and furnishings).
To this end, it will be particularly important both to select glass whose stratigraphy has certain technical characteristics, and to design suitable fixed and mobile shielding, with measures aimed at improving the quality of the diffused light inside the rooms.
There are countless design expedients to filter light: technologically advanced special glass (treated glass, glass with variable transparency, etc.); rigid screens that intercept and redirect the incident light (horizontal, vertical or grating protrusions; “shelves of light”, louvres, deflectors); fixed and mobile solar filters (brise-soleil, louvres, slats, darkening elements).