Page 294 - Materials Chemistry, Second Edition

278 4 Life Cycle Impact Assessment

reference to the fU is important for the impact assessment within LCA. The DALY
concept has, however, not been generally adopted.
Should toxicological effect data be present for a sufficiently large number of
substances, a HTP and the score S respectively (Equation 4.27) can be computed
if fate factors for the same sequence of substances can be computed. Here
and by international comparison of methods the largest difficulties occur because
multimedia models developed for various purposes, particularly for risk assessment
of chemicals provide strongly deviating results. 310) This can be due to the structure
of the models or the input data and simplifying assumptions. It is to the credit of
the globally acting ‘UNEP-SETAC Life Cycle Initiative’ 311) that the most important
model developers and users established a revised methodology ‘USEtox’. 312) by
model simplifications, comparative investigations and an inclusion of toxicological
effect data . For the first time it seems possible that a uniform sequence of several
thousands of recommended characterisation factors will be available particularly
for LCIA. Starting point for the development of USEtox were the following seven
LCIA and multimedia models:
• CalTOX (USA) 313)
• IMPACT 2002 (Switzerland) 314)
• USES LCA (the Netherlands) 315)
• BETR (Canada, the USA) 316)
• EDIP (Denmark) 317)
• WATSON (Germany) 318)
• EcoSense (Germany). 319)

Independent of LCIA issues nine multimedia models had been comparatively
investigated by a team of experts of the OECD 320) upon their suitability for the
computation of persistence and long-distance transportation potential. Starting
from these and in the context of OMNITOX (2004) conducted model comparisons
the most important elements of the model system were identified and implemented
into a basic model by consensus. 321) It was thus possible to eliminate the largest
deviations of the indicator results. Since multimedia models are better discussed in
the context of ecotoxicity these aspects will be included in Section 4.5.3.3. Typical
for human toxicity is the calculation of human exposure on the basis of a fate factor
(in conjunction with ecotoxicity), and the intake fraction as well as the human
EF. These factors are calculated for the most important intake pathways based on,

310) http://se.setac.org/files/setac-eu-0248-2007.pdf, http://www.lcacenter.org/InLCA2007/presentations/
97pdf
311) Specially: ‘Task Force on Toxic Impacts’, http://lcinitiative.unep.fr
312) USEtox: The UNEP/SETAC toxicity model; Rosenbaum et al. (2008, 2011).
313) McKone, Bennett and Maddalena (2001) and Hertwich et al. (2001).
314) Pennington et al. (2005).
315) Huijbregts et al. (2005b).
316) McKone, Bennett and Maddalena (2001).
317) Hauschild and Wenzel (1998).
318) Bachmann (2006).
319) EU (1999, 2005).
320) Fenner et al. (2005).
321) Rosenbaum et al. (2008).