The Kennedy Space Center maintains approximately $2 billion worth of ground support facilities to support its launch vehicle program. Maintenance of the ground facilities is a difficult and ongoing task since the Kennedy Space Center (KSC) is located in one of the most aggressive corrosion environments in the U.S. The effects of the corrosive environment at the KSC are compounded by the exhaust of the Space Shuttle's solid rocket boosters which produce an estimated 17 tons of hydrochloric acid with each launch. The Phase II project will continue the development of the models began in Phase I for classification of corrosion inhibitors for structural steel. We will produce even more robust models for selecting synergistic corrosion inhibitor compositions through a sequential program of algorithm development and high throughput electrochemical screening. We will then demonstrate the efficacy of the new compositions in protective coatings by electrochemical impedance studies, cyclic corrosion tests and outdoor exposures. In addition we will also develop toxicity classification tools for organic corrosion inhibitors. We will also scale up production of the corrosion inhibitor additive packages for evaluation by coating manufacturers.