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Understanding pre-calculated results

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justin.boucher@...'s picture
Understanding pre-calculated results

Hello, just a very quick and probably simple question here that I’m hoping someone can help clarify. Although I think it's straight forward, I didn’t see it clearly written anywhere else so far, and I apologize if there is something I overlooked.

I’m looking to understand the official pre-calculated USEtox results, specifically the characterization factors included in the USEtox results file “USEtox_results_organics.xls”.

Is it correct that characterization factors listed in this file as “n/a” have not been pre-calculated by USEtox due to a lack of available toxicity data?

For example, in the “Human tox CF” sheet, the substance n-pentane (CAS 109-66-0) has “n/a” listed for all entries. However, in the “Ecotox CF” sheet, characterization factors have been calculated for it. It seems this is because not enough human tox data was available in the input file, but for ecotox enough data did exist.

Is this correct? If yes: (i) is this the case for all of the substances listed in the results files as “n/a”? And (ii) to calculate CFs for such substances, would users need to find the appropriate missing tox data and then run the model themselves?


USEtox Team
USEtox Team's picture
USEtox missing characterization factors

When official characterization factors for substances included in USEtox are missing, this is exclusively due to missing substance input data. In case where characterization factors are available for ecotoxicity impacts but not for human toxicity impacts, this is most likely due to missing effect data for calculating human toxicity effect factors. This can be cross-checked by looking into the underlying substance database files in the USEtox "Input" directory.

For substances, where official characterization factors are missing in USEtox, users can arrive at their own characterization factors by finding themselves the relevant underlying substance data.