Derivation of health effect factors for nanoparticles to be used in LCIA

In this paper, we discuss the derivation of respiratory health effect factors (HEFs) for use in Life Cycle Impact Assessment (LCIA) for five nanoparticles: nanosilver, nano TiO2, carbon black, high-aspect ratio, rigid MWCNT and flexible MWCNT. For this purpose, we applied the methodology of USEtox™, a consensus model to calculate human toxicity and ecotoxicity characterization factors. In view of the available data, the non-carcinogenic HEFs for carbon black and TiO2 can be attributed the recommended status. For MWCNT and nanosilver the non-carcinogenic HEFs should be awarded the indicative status due to the minimal effects observed in the animal studies. All carcinogenic HEFs are currently labelled as indicative since there is no consensus with respect to the human relevance of the overload mechanism of carcinogenicity observed in rats exposed to poorly soluble particles (carbon black, flexible MWCNT and TiO2), whereas for high-aspect ratio, rigid MWCNT, the extrapolation from asbestos carcinogenicity introduces uncertainty. For nanosilver no carcinogenic HEF could be derived.