Chemical substances which are misused or released in the atmosphere are a threat to the environment and health. Accidents involving hazardous materials can occur anywhere chemical substances are manufactured, transported or stored. Chemical emergencies occur on highways, manufacturing facilities, pipelines and railways. Similarly emergencies can happen in residential areas where the chemicals are stored such as gasoline, pesticides etc (Lesak and David 1999). There has also been the use of chemical substances in terrorism activities. In the same way there are cases where natural disasters for instance flooding leading to chemical spill.