What is the importance of a hazardous substance?
There are several important implications. If your shipment contains a hazardous substance, the letters “RQ” must appear on the manifest in association with the basic shipping description. If you spill a hazardous substance (an “RQ”), you must notify the National Spill Response Center in Washington, DC. Materials that are not hazardous wastes may still be regulated under DOT if you are shipping in one container an “RQ” of a hazardous substance. In this case, the material would be a hazardous material regulated under DOT.