Hi,
I am studying a recycling system. First impact method I have used was ReCiPe. Results suggested that the system is sensitive to chlorine emissions to air and water in toxicological categories (Recipe H-Midpoint). Later, I decided to change it to ILCD impact method. It seemed more interesting for European context.
However, new results did not suggest the same. Toxicological ILCD categories are calculated with Usetox model. And it does not have any characterization factor related to chlorine emissions. I have checked it in original ILCD and USEtox websites and they are not For me it is strange the omission of one of, probably, one of the most important pollutants emitted (in amount and toxicity). I don´t know how to treat it. Can be interesting calculated? Can it be any reliable source where can it appear? Is there any reason for its omission or exclusion?
Chlorine is an inorganic substances that is emitted in various forms (e.g. different types of chlorides). Inorganic substances other than metal ions can currently not be characterized by any available LCIA method including USEtox. To be able to characterize inorganic substances, chemical- and compartment-specific reaction kinetics and dynamics would need to be developed that are currently not yet avaialable/not mature enough for inclusion into USEtox. This is the reason why currently there is no reliable characterization factor for chlorine in USEtox, since the fraction of any chlorine related emission that can be characterized is currently not known.
One potential way forward is to know all chlorine-related emission forms, all fractions of their related final reaction products in all environmental compartments and associated effect information to get a first combined proxy for a characterization factor. However, this is not implemented in any current LCIA method.