TRACI 2 Impact Assessment Method


The Tool for the Reduction and Assessment of Chemical and other environmental Impacts (TRACI), a stand-alone computer program developed by the U.S. Environmental Protection Agency specifically for the US using input parameters consistent with US locations. Site specificity is available for many of the impact categories, but in all cases a US average value exists when the location is undetermined. TRACI facilitates the Characterisation of environmental stressors that have potential effects, including ozone depletion, global warming, acidification, eutrophication, tropospheric ozone (smog) formation, ecotoxicity, human health criteria–related effects, human health cancer effects, human health noncancer effects, fossil fuel depletion, and land-use effects. TRACI was originally designed for use with life-cycle assessment (LCA), but it is expected to find wider application in the future.

This method presented in SimaPro 7 is originally based on TRACI v2.00 but it has expanded data derived from the release of TRACI at ecoinvent 2.0. Some impact categories were deleted to avoid double counting and some were renamed. This method replaces the “old” TRACI method in SimaPro.


Impact categories were characterized at the midpoint level for reasons including a higher level of societal consensus concerning the certainties of modeling at this point in the cause-effect chain. Research in the impact categories was conducted to construct methodologies for representing potential effects in the United States. TRACI is a midpoint oriented LCIA method including the following impact categories:

  • Ozone depletion
  • Global warming
  • Acidification
  • Eutrophication
  • Photochemical oxidation (smog)
  • Ecotoxicity
  • Human health: criteria air pollutants
  • Human health: carcinogenics
  • Human health: non-carcinogenics
  • Fossil fuel depletion(not implemented in SimaPro
  • Land use (not implemented in SimaPro)
  • Water use (not implemented in SimaPro)

For substances emitted to the sub compartment agricultural within the impact categories Ecotoxicity, Carcinogens and Non-carcinogens, the sub compartment is replaced by the sub compartment unspecified.

Normalization and weighting

The TRACI version implemented in ecoinvent data 2.0 is the one provided by Jane Bare in 2007, which does not contain Normalization factors. The normalization factors were recently published in ES&T (Bare and Gloria, 2007). PRé did not take over the Normalisation figures, as they are provided per compartment, what cannot be handled by SP yet. Moreover, using the total normalized values gave results that are difficult to understand or explain.



Summary of normalized values for TRACI Impact Categories for 1999


Summary of normalized values for TRACI Impact Categories for 1999 on a per capita basis


TRACI is a midpoint oriented life cycle impact assessment methodology, consistently with EPA’s decision not to aggregate between environmental impact categories. Arguing that normalization and valuation is still very much under debate and because of possible misinterpretation and misuse, the authors of TRACI determined that the state of the art for the normalization and valuation processes did not yet support inclusion in TRACI.

Download the Methods Manual (PDF, 0.6 MB) for a concise overview of the methods in SimaPro.