Dunnage is inexpensive or waste material used to load and secure cargo during transportation; more loosely, it refers to miscellaneous baggage, brought along during travel. The term can also refer to low-priority cargo used to fill out transport capacity which would otherwise ship underweight. In the context of shipping manufactured goods, dunnage refers to the packing material used as protective fill inside the carton, box or other type container used to prevent the merchandise from being damaged during shipment. These materials include bubble wrap; wadded, crumpled or shredded paper; styrofoam; inflated air packs; and other materials. International laws When unloading a ship, sometimes there is a problem as to what to do with the dunnage. Sometimes the dunnage cannot be landed because of customs duties on imported timber, or quarantine rules to avoid foreign insect pests getting offshore, and as a result often the unwanted dunnage is later furtively jettisoned overside and adds to the area's driftwood problem. According to U.S. and International Law (MARPOL 73/78) it is illegal for ships to dump dunnage within of the shore. Currently, the International Plant Protection Convention (IPPC), an international regulatory agency, mandates its 134 signatory countries to comply with the ISPM 15, which requires all dunnage to be heat-treated or fumigated with pesticides and marked with an accredited seal. There are several instances in which foreign insects have entered by land and caused devastation to the ecosystem, even ruining crops. Construction In construction, dunnage is often scrap wood or disposable manufactured material whose purpose is to be placed on the ground to raise construction materials to allow access for forklifts and slings for hoisting, and to protect them from the elements. Dunnage can also refer to a structural platform for mechanical equipment. Typically, these are open steel structures located on the roof of a building, consisting of steel beams supported on posts or bearing walls. They are used to raise equipment off the roof for various reasons, including maintenance access to both the roof surface and equipment itself, or to provide clearance to keep equipment out of any snow or rain that may collect on the roof. In this use, the dunnage is typically a permanent part of the building structure for the life of the equipment being supported. Dunnage bags Dunnage bags are air-filled pouches that can be used to stabilize, secure and protect cargo during transportation. Dunnage bags are placed