Hazardous materials are substances or materials which pose risk to life, health or property because of their chemical or biological nature.
Examples are petroleum, chlorine gas, sulfuric acid and hydrazine.
The U.S. Department of Transportation has determined that hazardous material is a substance or material which is capable of posing an unreasonable risk to health, safety and property when transported in commerce. Citizens may be notified by Emergency Alert System messages on radio or television, or by local emergency personnel. Some communities utilize emergency warning sirens. Check with your local emergency management office to find out if your community uses this system. Each hazmat incident is different and calls for a different response, which will be determined by the on-scene Incident Commander.