Dear USEtox team.
I have a question about the results of an ecotoxicity assessment: PAF (potentially affect fraction) of PDF (potentially disappeared fraction of species). How can I compare whether the effect on freshwater ecotoxicity is "high", "medium" or "low" because I have been studying only 1 chemicals, therefore cannot compare with other substances. Does USEtox have a criteria or toxic rating?
Thank you.
To evaluate whether the ecotoxicity characterization factor for a single chemical is high or low, you can compare it with respective factors for all substances that are already implemented in USEtox. In the file "USEtox_results_organics.xlsx", for example, you find all pre-calculated USEtox characterization factors for >3000 organic substances.
how can I determine the total ecotoxicity characterization factor to be included in the LCA analysis software?
All characterization factors offered through the formal USEtox model are already implemented in all major LCA softwares. Note that you cannot aggregate compartment-specific characterization factors - aggregation can only be done at the level of impact score, i.e. after combining compartment-specific emissions with their respective compartment-specific characterization factors.
Thank you for your reply. I would like to know more precisely how to apply in major LCA software the CFs obtained for substances not implemented on your database.
When substances are missing in the released USEtox versions, they have to be derived via the USEtox model files. The resulting characterization factors will have to be added manually in LCA software. For specific guidance on how to add charaterization factors in LCA software, please consult each software provider, since this procedure might differ for each software.