Desiccant masterbatches are plastic additives that are used to absorb moisture from the surrounding environment. They are often used in plastic products that are sensitive to moisture, such as food packaging and medical devices. These masterbatches contain a desiccant material, such as clay or silica gel, which is able to absorb moisture from the air and prevent it from reacting with the plastic. This helps to extend the shelf life of the product and maintain its quality.