Agents of Deterioration
Museum pieces are constantly under threat from the ten agents of deterioration - the forces that can
potentially harm our objects. They include things like water, chemicals, light and temperature.
When dealing with these agents the museum staff need to think about:
- preventing damage, eg fitting fire doors
- detecting or tracking the activities of the agents, eg thermometers or humidity sensors
- responding to the threat, eg killing pests like insects
- treating the damage, eg re-attach broken parts.
At each stage we think about risk - how do we limit the risk of damage and what is the safest way of treating
an object?
We also need to think about what the object is made from, eg animal hide, stone, wood, and how it was made (if
it is man-made). If we understand an object thoroughly we can pick the best way to store, display and preserve it.
Below are the ten agents, with information on how we prevent and respond to their threat.
A Secret Agent
While almost all damage to museum objects is caused by one of the above agents, some is actually down to the
object itself. Some objects are unstable because of the way they are made. For example,
- some types of vegetable tanned
leather suffer 'red rot'. This is where the leather becomes acidic, causing the fibres to break down. The surface or
grain layer flakes, and the flesh layer becomes very weak and powdery
- some types of glass are unstable because of their composition (the material they are made from).
They may easily shatter, or separate into layers like onion skins with an irridescent appearance. The surface
may become alkaline.
- some types of paper are acidic and quickly discolour and become brittle (newspaper)
- Maori grass skirts made from
traditional materials will fall apart because of the dyeing process used to colour them. The dyed fibres are acidic
from the start and tend to become more acidic over time so that they break down.
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