Environmental Monitoring

It is impossible to eliminate all the factors that cause cultural heritage materials to deteriorate, but we can slow down that process by controlling the environment in which those materials are stored. Temperature, relatively humidity, and light levels are three environmental conditions that can have an impact on the rate of decay.

In general, cooler temperatures are better. Humid environments put historical materials at risk of mold growth and environments with very low humidity can cause paper to become dry, brittle, and weak over time. Fluctuations in temperature and humidity should be kept to a minimum. All light provides energy that fuels chemical reactions, causing materials to fade, change color, or darken, and damage is cumulative and irreversible.

About a third of Vermont historical records repositories do not control temperature, humidity, or light levels at all, and water/moisture and light exposure are the third and fourth highest causes of damage to collections, as self-reported in the 2021 VHRP Survey.

The best way to protect against mold and other environmental threats is through environmental monitoring, which tracks temperature, relative humidity, and light exposure over time.

The Vermont Historical Records Program (VHRP) coordinates an environmental monitoring program to help repositories establish baseline conditions for storage environments over the course of a calendar year. We loan either a gateway and two sensors from Conserv (conserv.io) or HOBO dataloggers, depending on availability and the presence of wireless or cell service at your repository. Based on the data, VHRP staff can recommend ways to improve conditions during the loan period and draft an environmental analysis report at the end of the loan to help make the case for HVAC improvements or for purchasing dataloggers so the storage environment(s) can continue to be monitored.

For more information, please contact us at sos.vhrp@vermont.gov.

To learn more about environmental best practices, please see our online resource library.