Preventive Conservation

The control of environment, handling, and risks to slow the deterioration of collections without directly treating individual objects.

Definition

Preventive conservation is the practice of minimizing damage to cultural heritage by controlling the conditions and risks to which objects are exposed, rather than by intervening on the objects themselves.

Scope

This topic covers the proactive, collection-wide measures that reduce the rate of decay: managing temperature, relative humidity, light, and pollutants; integrated pest management; safe storage, handling, packing, and transport; emergency preparedness; and risk assessment. It frames preservation as the management of a defined set of deterioration agents across whole collections rather than the treatment of single objects.

Core questions

• What environmental factors cause collections to deteriorate?
• How are temperature, humidity, light, and pests managed?
• How can risks to whole collections be assessed and prioritized?
• Why is prevention preferred over remedial treatment?

Key theories

The agents of deterioration

Michalski's framework identifies ten agents of deterioration — such as light, incorrect humidity and temperature, pests, pollutants, and physical forces — providing a systematic basis for assessing and controlling threats to collections.

The museum environment

Thomson established the scientific basis for controlling light, humidity, and air quality in museums, defining target conditions and the trade-offs involved in protecting different materials.

History

Scientific environmental control in museums was systematized by Garry Thomson's The Museum Environment (1978; 2nd ed. 1986). From the 1990s the field moved toward risk-based and sustainable approaches, with frameworks such as the Canadian Conservation Institute's agents of deterioration and growing debate over relaxing strict climate standards to reduce energy use.

Debates

Tight versus flexible climate standards

The field debates whether collections require narrowly controlled temperature and humidity or can tolerate wider, more sustainable ranges, balancing object safety against energy cost and environmental impact.

Key figures

• Garry Thomson
• Stefan Michalski
• Jonathan Ashley-Smith

Seminal works

• thomson1986
• michalski2007
• ashleysmith1999

Frequently asked questions

What is preventive conservation?

Preventive conservation is the management of environmental conditions, handling, storage, and risks to slow the deterioration of entire collections, as distinct from treating individual objects directly.

What are the main threats to museum collections?

Common agents of deterioration include incorrect temperature and relative humidity, light and ultraviolet radiation, pollutants, pests, physical forces, fire, water, theft, and the dissociation of objects from their records.