The role of the preventive conservation section is to manage potential hazards within the museum, stores and off-site locations to ensure the long-term survival of the collections. All materials eventually decay, however, the rate at which this occurs depends on a variety of factors including the environment (e.g. humidity, heat, light), chemical agents (e.g. pollutants), biological agents (e.g. mould and pests), and physical agents such as handling, transport and vibrations.
The collections are composed of an array of materials, each of which need specific environmental parameters in order to remain relatively stable. When the environment is not controlled, decay can occur at a faster rate.
- high relative humidity (RH) can cause metallic corrosion and mould growth
- fluctuating RH can cause shrinkage and swelling of moisture-containing materials such as leather and wood
- changes in temperature can affect the rate of reactions and structural integrity of objects
- visible and ultraviolet light can cause chemical changes in various materials, such as fading of dyes and pigments.
Preventive conservation aims to reduce the rate of decay by managing and monitoring the environment in which objects are displayed. Objects with similar environmental requirements are displayed together within climate-controlled showcases and galleries. Environmental control measures used in the museum include air handling systems (that introduce conditioned air at the required RH and temperature), humidification and dehumidification equipment, silica-based desiccants, low-level lighting with UV filters, window blinds and screens.
The preventive conservation section also provides a materials testing service to ensure that display and storage environments are not compromised by the presence of harmful substances in construction materials.