The cooling packs contain highly water-absorbent resin. This resin can hold water up to its capacity. When the ambient humidity level drops, the resin releases evaporated water, adjusting the humidity around it. Thus, these cooling sheets provide a good mechanism for humidity control. It is important that seafood remains fresh until it is delivered to customers. Letﾕs be careful in maintaining the freshness of delicious foods. This photograph shows several sample products that have absorbed water and then been frozen. Copyright(C) 2002-2007 Taihei Co. All rights reserved.