IEC 60749-39:2021 is available as IEC 60749-39:2021 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.

IEC 60749-39:2021 details the procedures for the measurement of the characteristic properties of moisture diffusivity and water solubility in organic materials used in the packaging of semiconductor components. These two material properties are important parameters for the effective reliability performance of plastic packaged semiconductors after exposure to moisture and being subjected to high-temperature solder reflow. This edition includes the following significant technical changes with respect to the previous edition:

- updated procedure for "dry weight" determination.