GaBi Solutions




USEtox is developed under the United Nations Environment Program (UNEP) and the Society for Environmental Toxicology and Chemistry (SETAC) Life Cycle Initiative, directly involving the model developers of CalTOX, IMPACT 2002, USES-LCA, BETR, EDIP, WATSON and EcoSense.



The USEtox model operates on two scales; the continental scale and the global scale. The continental scale consists of six compartments: Urban air, rural air, agricultural soil, natural soil, freshwater, and coastal marine water. The global scale has the same structure, but without the urban air. The scales and compartments and the exchanges modelled are indicated in the figure .

USEtox calculates characterisation factors for human toxicity and freshwater ecotoxicity via three steps:


  • Environmental fate, where the distribution and degradation of each substance is modelled
  • Exposure where the exposure of humans, animals and plants are modelled and
  • Effects, where the inherent damage of the substance is researched


Human effect factors relate the quantity taken in to the potential risk of cancerous and non-cancerous effects expressing cases per kg of chemical emitted. The final unit is comparative toxic units (CTUh).

Effect factors for freshwater ecosystems are based on species-specific data of concentration at which 50% of a population displays an effect, expressed as an estimate of the potentially affected fraction of species (PAF) integrated over time and volume per unit mass of a chemical emitted (PAF m3-day/ kg).  The final unit is comparative toxic units (CTUe).

The model provides both recommended and interim characterisation factors for human health and freshwater ecotoxicity impacts.

Only the recommended factors are included in GaBi as a standard setting. Nevertheless an import file containing the interim factors can be downloaded. Save the file onto your computer. Open a GaBi database and go to Database -> Import -> GaBi eXchange file (*.gbx) and import the file.

The interim factors are estimated with a higher degree of uncertainty than the recommended and should be used with caution. If interim factors are dominating the result of a Life Cycle Assessment a sensitivity analysis should be carried out.

Importing the file will import a lot of substances that are not characterised in other methodologies (e.g. UBP, EDIP etc).

PE INTERNATIONAL AG and LBP-GaBi cannot be held responsible for any of this information and data.



Normalization references are developed for Europe and North America



Rosenbaum RK, Bachmann TK, Gold LS, Huijbregts MAJ, Jolliet O, Juraske R, Koehler A, Larsen HF, MacLeod M, Margni M, McKone TE, Payet J, Schuhmacher M, Van de Meent D and Hauschild MZ (2008), USEtox - The UNEP/SETAC-consensus model: recommended characterisation factors for human toxicity and freshwater ecotoxicity in Life Cycle Impact Assessment. International Journal of Life Cycle Assessment 13(7): 532-546.
Hauschild MZ, Huijbregts MAJ, Jolliet O, MacLeod M, Margni M, Van de Meent D, Rosenbaum RK and McKone TE (2008). Building a model based on scientific consensus for Life Cycle Impact Assessment of Chemicals: the Search for Harmony and Parsimony. Environmental Science and Technology 42(19): 7032–7037.
Laurent A, Lautier A, Rosenbaum RK, Olsen SI and Hauschild MZ (2011). Normalization references for Europe and North America for application with USEtox™ characterization factors The International Journal of Life Cycle Assessment 16 ( 8), 728-738, DOI: 10.1007/s11367-011-0285-7


Complete model and characterisation results can be downloaded from the USEtox website.

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