The 'ten agents of deterioration' are a conceptual framework developed by the Canadian Conservation Institute (CCI) used to categorise the major causes of change, loss or damage to cultural heritage objects (such as collections held by galleries, libraries, archives and museums). Also referred to as the 'agents of change', the framework was first developed in the late 1980s and early 1990s. The defined agents reflect and systematise the main chemical and physical deterioration pathways to which most physical material is subject. They are a major influence on the applied practice of conservation, restoration, and collection management, finding particular use in risk management for cultural heritage collections.
CCI defines ten 'agents': dissociation, fire, incorrect relative humidity, incorrect temperature, light and ultraviolet light, pests, pollutants (or contaminants), physical forces, thieves and vandals (at times referred to as 'criminals'), and water. The number of primary agents has remained the same since the 1994 with the addition of 'custodial neglect' (now termed dissociation), though the scope and names of some categories have been updated over time to reflect new research or thinking.
Each category may be further subcategorised as rare and/or catastrophic (Type 1), sporadic (Type 2), or constant/ongoing (Type 3), particularly when applied to risk assessments. For example, within the category of physical forces, an earthquake may be designated a Type 1 event; a handling accident where an object is dropped as Type 2, and ongoing physical wear from daily handling as Type 3.
Dissociation
Dissociation refers to the loss of information associated with an object, such as provenance or location information, without which the object loses significance or is lost. In earlier versions of the framework this was referred to as 'custodial neglect'. Dissociation can cover loss of identification labels, misplacement of parts of an object, lack of descriptive information for example. Neglecting a collection is also part of dissociation. By not doing the proper research and not making sure everything stays together, institutions can lose information and cause their collections to lose value.
Dissociation can also be caused because of a natural disaster.
Having a good documentation plan and a good backup for the electronic system can help mitigate the damages done by events we cannot control.
Rigorous information management protocols are necessary, such as regular collection audits and administrative reviews. A good documentation practice and making sure the labels are following their respective object is essential to help prevent dissociation.
Fire
Fire directly consumes cultural heritage through burning or by the deposition of smoke and soot on surfaces. Fire suppression systems can also cause damage - e.g. water damage from sprinklers. For example, about 18 million objects were destroyed in the 2018 fire at the National Museum of Brazil.
Preventive maintenance is critical to prevent and minimize the risk of fire. Strategies include banning smoking and other sources of flame and heat, routine maintenance of fire extinguishers, maintaining a regular schedule for the maintenance and testing of smoke detectors, and protecting the building and contents with [Sprinkler Systems|sprinkler systems].
Materials can be classified based on their level of vulnerability to heat and combustion. Jean Tetrault identified five levels of sensitivity—from very low for non-combustible materials to very high for self-igniting, easily combustible materials. Inorganic materials, such as ceramics, stone, glass, and metal, have lower relative sensitivity to fire, as compared to organic materials, such as wood, paper, or textile, that are highly reactive to fire. Certain materials are known for their extremely high relative sensitivity to fire, such as organic solvents with a flash point below 32oC that makes them flammable and most dangerous if it goes below 21oC.
An object’s susceptibility to fire is a salient factor that affects the rate at which fire can spread within space. Considering that fire is an exothermic chain reaction that produces energy in the form of light and heat, it is important to note that for the chain reaction to persist, the fuel must be in a suitable condition and quantity. If the material is wet, the heat produced will react first with water to remove moisture instead of directly causing the fuel to break down and cause the chain reaction to continue should there be enough fuel source to feed on.