Larger desiccants are frequently utilized to protect goods shipped in containers from moisture damage. Container desiccants decrease the level of moisture in the container and protect all the goods and packaging from high relative humidity and container rain which can cause an assortment of damage to goods please note that a unit of desiccant refers to its drying capacity, Not its volume. A unit approximately one ounce represents the quantity of desiccant that will absorb at least three grams of water vapor at 20% relative humidity and at least six grams of water vapor at 40% relative humidity at 77 degrees f 25 degrees c .