Engineered nanomaterials (generally defined as being 1-100 nm is size) take on unique activities due to their small size, reactivity, and high surface area to mass ratio. While these properties can be highly desirable for the intended function of the materials and the products produced from them, they may also cause undesirable activity in environmental or biological systems. EPA program offices, faced with applications for novel engineered nanomaterials, need access to relevant data to help predict potential environmental/biological interactions of nanomaterials based on their physio-chemical properties and the intended uses of novel materials. We have developed a relational database containing the results from the Office of Research and Development (ORD) regarding the actions of engineered nanomaterials in environmental and biological systems. The database captures the chemical and physical parameters of the materials tested, the assays in which they were tested, and the measured results. The database is designed to enable selective searches of nanomaterials based on physical/chemical parameters such as composition, size, coatings, etc, the system in which they were tested, and the quantitative results obtained. For example, a user would be able to access information on materials of similar composition, size range, reactivity, or other properties measured, and see what results were observed. For example, users can implement observed results for modeling and prediction for similar nanomaterials using quantitative structure activity relationships and other sophisticated modeling approaches.