Hygroscopic compounds will absorb water from the atmosphere and should be stored dessicated and protected from exposure to the air as much as is possible/practical. These compounds are normally crystalline solids in their dry state, but if they have been exposed to air, they may look wet, or even appear like droplets of liquid. For some components exposure to moisture may be detrimental. Please contact our technical support for more product-specific recommendations regarding handling and reconstitution of individual compounds.