Department of Transportation (DOT) and United Nations (UN) hazardous materials shipping labels and placards are used to clearly identify shipments containing hazardous materials. Each label or placard has text and/or images that correspond to a specific type of hazard or hazardous material. These items help companies comply with government regulations regarding the shipment of dangerous materials, and they help people who handle and receive these shipments determine whether they need special handling or safety protocols. They also can help emergency responders determine how to clean up or evacuate the area around the shipments if there is an accident during transportation. Labels are applied to individual containers such as drums, cartons, crates, pails, and compressed-gas cylinders. Placards are affixed to transport vehicles such as vans, tractors, trucks, and semi-trailers. Placards are sometimes also used on portable tanks and other large individual containers.