Exploring

Environmental Control

Guidelines for Temperature and RH

There is no national standard for climate-controlled storage of paper collections, but the National Information Standards Organization (NISO) has issued a technical report entitled Environmental Guidelines for the Storage of Paper Records (NISO-TR01-1995), available from NISO. This publication gives suggested values for temperature and relative humidity for storage of paper records, which are summarized here:

Situation	Temperature	Relative Humidity
Combined stack and user areas	70 °F maximum*	30-50% RH**
Stacks where people are excluded except for access and retrieval	65 °F maximum*	30-50% RH**
Optimum preservation stacks	35-65°F***	30-50% RH**
Maximum daily fluctuation	±2°F	±3% RH
Maximum monthly drift	3°F	3%

* These values assume that 70°F is about the minimum comfort temperature for reading and 65°F the minimum for light physical activity. Each institution can make its own choice.
** A specific value of relative humidity within this range should be maintained ±3%, depending on the climatic conditions in the local geographic area, or facility limitations.
*** A specific temperature within this range should be maintained ±2°F. The specific temperature chosen depends on how much an organization is willing to invest in order to achieve a given life expectancy for its records.

from Environmental Guidelines for the Storage of Paper Records, p. 2