Note: EPA no longer updates this information, but it may be useful as a reference or resource.
EPA has developed an evaluation tool, the PBT Profiler, which predicts PBT potential of chemicals. The PBT Profiler is an assement tool that estimates environmental persistence (P), bioconcentration potential (B), and aquatic toxicity (T) of discrete chemicals based on their moleccular structure. It is Internet-based and there is no cost for use. The user enters a chemical using the Chemical Abstract Service Registry Number (CASRN) . If the chemical is in the accompanying database of more than 100,000 chemicals, the structure is retrieved and entered into the model. A drawing program is also available so that the user can draw and enter the structure or the structure can be entered as a line notation using the Simplified Molecular Input Line Entry System (SMILES).
The PBT Profiler is a web-based evaluation tool that may be valuable for those developing new chemicals or considering the use of new chemicals. The PBT Profiler estimates environmental persistence (P), bioconcentration potential (B) and aquatic toxicity (T) of discrete chemicals, based on their molecular structure. There is no cost for using the assessment tool.
What does the PBT Profiler do?
The model compares results with the PBT criteria established for Premanufacture Notices (PMNs) submitted under section 5 of TSCA; and the final rule for reporting chemicals under the Toxic Chemical Release Inventory (TRI), under section 313 of the Emergency Planning and Community Right-to-Know Act (EPCRA). Results are displayed in three levels of detail, with the most comprehensive being information useful for management of any potential risks associated with the chemical.
Why was the PBT Profiler Developed?
The PBT Profiler is a subset of methods included in the P2 Framework, which is an approach to risk screening that incorporates pollution prevention principles in the R&D stage of chemical development. The models contained in the P2 Framework are used, along with other information, by OPPT to screen new chemicals in the absence of data. The goals of the P2 Framework and PBT Profiler approach are to inform decision-making at the earliest stages of R&D, increase opportunities for innovation, and promote the selection and application of safer chemicals and processes. The PBT Profiler is a subset of estimation methods included in OPPT's P2 Framework. The P2 Framework web site explains the use and application of the models and allows users to download the P2 Framework Manual.
EPA does not rely solely on results of screening level methods, such as the PBT Profiler, to regulate chemicals! Users should remember that this is a screening level method that provides estimates of PBT characteristics, and is useful for establishing priorities for chemical evaluation when chemical-specific data are lacking. This, and any screening level method, should be used with caution! If the PBT Profiler identifies an issue of potential concern, additional data should be gathered and/or additional analyses conducted to come to an informed decision about the chemicals under review. Not all types of chemicals are appropriate for evaluating with the PBT Profiler. There are limitations associated with the PBT Profiler, and these are highlighted and explained for the user within the model itself.
For information on the PBT Profiler please contact:
Bill Waugh, Program Manager
Maggie Wilson, Technical Lead