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About the PBT Profiler


The PBT Profiler was designed to be an easy to use, widely available, no-cost tool to screen chemicals lacking experimental data in order to help identify pollution prevention (P2) opportunities. It is a continuation of  the Office of Chemical Safety and Pollution Prevention (OCSPP, U.S. Environmental Protection Agency) Pollution Prevention (P2) Assessment Framework - a collection of screening models and methods to help promote the design, development, and application of safer chemicals and processes. The P2 Framework uses computerized methods, such as structure/activity relationships (SARs) and standard scenarios, to predict risk related data (physical/chemical properties, bioconcentration, environmental fate, carcinogenicity, toxicity to aquatic organisms, worker and general population exposure, and other information) on chemicals lacking experimental data. The PBT Profiler arose from experience gained in the P2 Framework's outreach program, a vigorous set of initiatives by collaborators in the business, government, and academic sectors to promote the voluntary use of these tools to reduce pollution and highlight the potential economic benefits of informed environmental decision making.


The PBT Profiler uses a subset of P2 Assessment Framework computer-based tools to help identify chemicals that potentially may persist, bioaccumulate, and be toxic to aquatic life, i.e., PBT chemicals. The release of even small amounts of persistent, bioaccumulative, and toxic chemicals to the environment is of concern because they can accumulate over time to higher concentrations and, therefore, have a higher potential to adversely impact human health and the environment. The overwhelming majority of known chemical substances do not have experimental persistence, bioaccumulation, and toxicity data available. Only a small fraction of chemicals currently in commerce, including the 2,000 new chemicals introduced each year, have sufficient data available to perform a thorough evaluation of potential risks. The PBT Profiler was designed to help interested parties voluntarily screen chemicals for persistence, bioaccumulation, and aquatic toxicity characteristics when no experimental data are available.


It is important to stress that the PBT Profiler is a screening level predictive tool and cannot be used for all chemical substances. The methodology the PBT Profiler uses has been developed by government, academic, and private-sector researchers over the past 20 years and represents some of the best techniques currently available. Nevertheless, the PBT Profiler is a tool that, like all tools, has strengths, weaknesses, and limitations.  These limitations should be considered before using this model.  For example, predicted data should never be used in place of experimental data.  Additional model limitations are described on this web site.  When properly applied,  the PBT Profiler can provide a straight-forward estimate of persistence, bioaccumulation, and aquatic toxicity based on widely accepted criteria. This information can help interested parties to identify pollution prevention initiatives and aid in their chemical selection processes.


Many chemicals can be profiled in one on-line session.  The PBT Profiler provides three integrated levels of output for each chemical inclduing (1) easy to read color-coded comparisons of predicted values to PBT criteria; (2) predicted values for P, B, and T; and (3) narrative descriptions of pollution prevention considerations for each chemical. For rapid recognition of the estimated results, the "P", "B", and "T" designators (corresponding to persistence, bioaccumulation, and toxicity, respectively) are shaded orange or red if a chemical exceeds the defined thresholds for each criteria; if the thresholds are not exceeded, the designators are shaded green. Numeric estimates in a tabular format are also provided for persistence (in air, water, soil, and sediment), bioaccumulation, and toxicity. To put these results in perspective, pollution prevention considerations for each chemical profiled are also provided in narrative available by clicking on the “P2 Considerations” link on the Results page. More information on interpreting the PBT Profiler estimates is available on this web site.

Security and Privacy Issues

Throughout its development, concerns over protecting the privacy and security of chemical information sent over the internet to the PBT Profiler have been a high priority. Users of the PBT Profiler do so completely anonymously and no user or chemical information is purposefully stored, tracked, monitored, or analyzed. Additional notes on security and anonymity, including technical details, are available for those interested.  Depending on user feedback, future versions of the PBT Profiler may offer advanced options such as the use of encrypted data transfer, or development of a downloadable, stand alone version of the model that can be used off line.

The PBT Profiler results are available for 20 minutes after the last page is requested.

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Developed by the Environmental Health Analysis Center under contract to the Office of Chemical Safety and Pollution Prevention , U.S. Environmental Protection Agency
Computer Resources Donated by SRC, Inc.          Ver 2.001     Last Updated September 28, 2016