P2P (Pollution Prevention Progress) is a novel computer-based tool, developed to facilitate the comparison of processes and products in the context of their potential contribution to environmental and human health impacts.  In addition to regulatory information, ten impact categories and a number of subcategories are represented.  The database includes default values for approximately 3000 chemicals.  The data is used to identify applicable regulations, impact categories and, where appropriate, relative impact potentials for each chemical.  The default potentials are a function of the release media and were calculated to provide US averages.

The default impact potentials in P2P are derived scientifically taking into account the necessary trade-offs between data availability and uncertainty.  Each potential comprises of a fate, exposure and effect component.  Unlike a number of comparison tools for life-cycle analysis (LCA) and pollution prevention, P2P takes into account the ability of chemicals to be transported between environmental media after release.  The models used to derive the potentials are made readily available to provide designers with the flexibility of extending the database or modifying the default values for case-specific scenarios using minimal resources.

The mass or concentration of an emission is normally restricted by regulations to limit impacts.  Legislation is typically process orientated, i.e. addresses emissions from individual facilities.  Hence, in theory, adverse impacts associated with single emissions are typically prevented or minimised.  Today, impacts are commonly the result of long-term exposure to many sources rather than particular emissions.  Therefore all emissions can be considered relevant in pollution prevention, whether above or below a no effect level.  In addition to identifying potentially applicable regulations, P2P facilitates the comparison of process and product alternatives in terms of their contribution to potential regional and global scale impacts.