P2OASys allows companies to assess the potential environmental, worker, and public health impacts of alternative technologies aimed at reducing toxics use. The goal is more comprehensive and systematic thinking about the potential hazards posed by current and alternative processes identified during the TUR planning process. The tool can assist companies to systematically examine the potential environmental and worker impacts of options, while examining the total impacts of process changes, rather than simply those of chemical changes. It also allows for a comparison of options with current processes, based on quantitative and qualitative factors. Embedded formulae in P2OASys provide a numerical hazard score for the company's current process and identified options, which can then be combined with other information sources and professional expertise to make decisions on adoption of alternatives. Companies input both quantitative and qualitative data on the chemical toxicity, ecological effects, physical properties, and changes in work organization likely as a result of the proposed option.