What is the maximum percent of relative humidity that can be exceeded for a location to be classified as dry?

A location is classified as dry when the relative humidity is low enough to create an environment that is comfortable and conducive to certain activities, often related to pharmaceuticals and storage conditions. The threshold for this classification is generally accepted to be a relative humidity that does not exceed 40%.

This percentage of relative humidity indicates that the air is dry enough to prevent excessive moisture accumulation, which can be critical in various settings, including pharmacies where moisture could affect the stability and efficacy of certain medications. A relative humidity exceeding 40% would typically be considered unsuitable for conditions requiring dry environments.

Understanding this classification is essential for pharmacy technicians, as baseline humidity levels can influence storage protocols for various pharmaceuticals, especially for those sensitive to moisture.