Moisturesensitive

Moisture sensitivity describes the tendency of a material or product to interact with ambient moisture in ways that can change its properties, performance, or integrity. Sensitivity depends on the material’s chemistry, porosity, moisture content, and exposure conditions such as temperature and humidity. Items described as moisture-sensitive span electronics, hygroscopic polymers and ceramics, certain pharmaceuticals, and some agricultural products.

In electronics, moisture sensitivity is commonly expressed as a moisture sensitivity level (MSL), which indicates how long a device may be exposed to ambient conditions before assembly and how much drying may be required prior to soldering. Moisture absorption can lead to problems such as blistering, delamination, or damaged solder joints when heated during reflow. Standards organizations, including IPC and JEDEC, provide classifications and handling guidelines that cover storage duration, bake-out requirements, and packaging with desiccants and humidity indicators.

Materials science and packaging also address moisture sensitivity. Hygroscopic materials absorb water, which can cause dimensional changes, swelling, chemical instability, or degraded mechanical properties. Moisture control is achieved through barrier packaging, desiccants, and permeability testing. In pharmaceuticals and food, moisture sensitivity affects shelf life and stability, necessitating moisture-protective packaging and controlled humidity environments during manufacturing and storage.

Testing and assessment often involve humidity–temperature exposure, dynamic moisture sorption measurements for polymers, and related permeability or uptake tests. Standards from IPC, JEDEC, IEC, and ASTM guide methods and acceptance criteria for moisture-related risks.

Mitigation strategies include drying or bake-out procedures, humidity-controlled storage, moisture-barrier packaging, and the use of desiccants and humidity indicators to maintain safe conditions for moisture-sensitive items.