ABSTRACT
Any finite space, whether it is a box, a room, or a building, contains an environment, the totality of the surrounding conditions and circumstances. There are two basic elements in an environment: matter, both organic and inorganic; and energy. Since no matter–energy system is completely inert, all the parts and activities form a chain of action–reaction. The conservation mission of a museum requires that such interactions be kept to a minimum. This means controlling the factors that promote interaction. Those factors are:
temperature
relative humidity
dust and pollutant gases
biological organisms
reactivity of materials
light
