The goal of this project is to develop an XML-driven platform that will rapidly determine the hazards associated with a collection of chemicals at a given location. Beginning with a query consisting of location, date, and time, the CHAIN (Chemical Hazard Assessment Information Network) system will prioritize the materials at the location to provide a ranked list by hazard along with recommended protective measures. This will allow mission planners or emergency response personnel to make decisions based on current materials knowledge and provide an estimate of the associated hazards and priority of those hazards. The system will access site-specific inventory data and individual material hazard information to develop the hazard assessment. In addition, access to GIS and weather data will allow for further modelling of site-site interactions and atmospheric transport of hazardous materials. The system will be developed using using XML to allow ready interchange of data into and out of the model. The formatting of the CHAIN system output will be selectable by the user to provide needed level of material detail, recommended response, and speed in sorting through complicated collections of hazardous materials. CHEMICAL, HAZARD ASSESSMENT, HAZARD RANKING, WEB SERVICES, XML, MODELING