The U.S. Environmental Protection Agency (EPA) has statutory authorities and responsibilities to prepare for and respond to emergencies involving oil and hazardous substances, pollutants or contaminants, which include chemical, biological and radiological materials that could also be components of a weapon of mass destruction (WMD). A WMD is defined as a weapon, device, or large conventional explosive that produces catastrophic loss of life or property. EPA carries out its preparedness and response efforts primarily under the mandate of the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) and the Radiological Response Program. EPA provides technical support, response coordination and management, and resource assistance to local and state first responders under the National Response System (NRS). The NRS is the federal government's mechanism for emergency response to releases of hazardous substances, pollutants, and contaminants and discharges of oil that threaten human health and the environment. The NRS is fully described in the NCP at 40 CFR Part 300.