USEtox characterisation factors - differences in ecoinvent v2.2 and v3.1

[dmutz]

Hello,

for human toxicity potential and ecotoxicity potential I want to use USEtox model.
In some projects I am currently using ecoinvent v3.1 database. But in other projects ecoinvent v2.2.

Now, I noticed strong deviations in CF by using both databases (separately), that the characterisation factors for same materials with (more or less) the same emission type, e.g. water/river or water/surface, respectively.

Is this described fact just an error within the database or does ecoinvent v2.2 really account USEtox indicators with other CF than in v3.1?

An example (for ecotoxicity CF for USEtox w/o LT):

• 1,4-Butanediol:
• no CF (v2.2) - emission into water, river
• 7,31 CTUe (v3.1) - emission into water, surface water
• Cadmium, ion:
• no CF (v2.2) - emission into water, river
• 9 712 CTUe (v3.1) - emission into water, surface water
• Mercury:
• 22 090 (v2.2) - emission into water, river
• 22 090 CTUe (v3.1) - emission into water, surface water

In this example: Mercury does have the same CF, but Cadmium has not. Why?

[dmutz]

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[pbeilschmidt]

Hello dmutz,

I can confirm your observation that there are no characterization factors present for the elementary exchanges '1,4-butanediol' and 'Cadmium, ion' for the USEtox w/o LT impact assessment method in ecoinvent v2.2. However these CF exist in the current ecoinvent v3.1 database.
In contrast, 'Mercury', does have a characterization factor in the USEtox w/o LT method, both in the old ecoinvent v2.2 database (2010) as well as in the current ecoinvent v3.1 database.

When I see such a phenomenon, I typically check the LCIA factors in my local Umberto NXT LCA installation first (I'm lucky to have both version still installed). After verifying it in Umberto, I then check whether the values I have locally are identical to the ones provided directly by ecoinvent. I typically look directly in the online database at ecoinvent.org. ecoinvent v2.2 data is still available.

Now, for the issue you addressed: Looking at USEtox w/o LT the elementary exchanges '1,4-butanediol' and 'Cadmium, ion' do not exist, while 'Mercury' exists. See attached screen grab (I have blacked out the values just in case this would be a license infringement ... although I think these CF are in the public domain).

My guess is that the USEtox w/o LT method was not correctly implemented by ecoinvent back in 2010, and that they corrected it when moving to ecoinvent v3. However, I didn't find a mention of this in the change report.

Maybe you can get a confirmation on this directly from the colleagues at ecoinvent.org.

[pbeilschmidt]

The continuation of this thread can be found in the ecoinvent forum. The original poster dmutz has raised the question in the ecoinvent forum 'Differences between ecoinvent v2 & v3'.

An interesting blog post from our colleagues at PRé. Tommie Ponsioen writes about 'Why My LCA Scores Radically Changed After The ecoinvent Update'.

Worth a read also for Umberto NXT users working with ecoinvent v3.1 data.