• Software in a spreadsheet format containing multimedia chemical fate models;
• A tool for estimating overall persistence (P_OV) and long-range transport potential (LRTP) of organic chemicals at a screening level;
• A tool for comparative assessment of environmental hazard properties of different chemicals. Specifically designed to help identify potential POPs (Persistent Organic Pollutants) according to persistence and long-range transport metrics.

1. Simple and easy to use

The OECD P_OV   and LRTP Screening Tool has a “Main menu” for entering data and results are shown in easy to read graphical mode, which allows even beginners to utilise it easily.

2. Flexible Data Management and Model Setting

Users can choose chemicals from a database installed in the Tool, or enter data for chemicals of interest, i.e. physical-chemical properties and degradation half-lives. It is possible to import users’ own databases and store them within the Tool. It is also possible to change model settings.

3. Representative of several models

The model in the Tool was developed as a “consensus model” reflecting features of several existing multimedia fate and transport models. The latest version of the Tool also includes the implementation of the Emission Fractions Approach (EFA).

4. Graphical and Numerical Output

The results of the model calculation are shown in both numerical and graphical outputs, such as:

• Numerical values of EFA metrics (φ1 - Dispersion, φ2 - Transfer, φ3 - Accumulation), P_OV  and CTD (Characteristic Travel Distance) in three emission scenarios: to soil, water and air.
• Plots of CTD and φ2 vs. P_OV.
• EFA Details: Plots of the EFA metrics, including stacked bar graphs showing the contribution of air and water advection, and portions transferred and accumulated in remote water and soil, for each scenario.
• Classic Details (comparable to previous versions): Pie charts showing the fraction of chemicals that are contained in soil, water and air for each scenario.
  

The Tool originated from the OECD/UNEP Workshop on the Use of Multimedia Models, held in Ottawa, Canada, in 2001. Following the workshop, an OECD Expert Group was established to follow up on the recommendations, and between 2002 and 2005 the Group developed a consensus model based on existing approaches for predicting overall environmental persistence and long‑range transport.

The software was developed with contributions from Switzerland and Germany, under OECD oversight, and in collaboration with participants in the OECD/UNEP Training Workshops on the Application of Multimedia Models for the Identification of Persistent Organic Pollutants (POPs) held in 2005 and 2006.

An initial version of the Tool (Version 2.1) was endorsed by the OECD Task Force on Environmental Exposure Assessment and published in 2008, followed by Version 2.2 in 2009. Since then, the Tool has been widely used by OECD member and non‑member countries to support screening‑level assessment of chemical overall persistence and long‑range transport.

In line with its continued relevance, ongoing use, and evolving scientific needs, the OECD Working Party on Exposure Assessment (WPEA) initiated a comprehensive review of the Tool, published in 2023 (ENV/CBC/MONO(2023)36).