ILCD Handbook: Framework and requirements for LCIA models and ...

ILCD Handbook: Framework and requirements for LCIA models and indicators First edition
4.9 Ecotoxicity
4.9.1 Framework and scope
Models and factors for toxicity effects in LCA must be based on the relative risk and
associated consequences of chemicals that are released into the environment. These must
build on the principles of comparative risk assessment, while providing indicators linked to
the Area of Protection ‗Natural Environment‘ (see Chapter 3.2).
LCA characterisation models and factors for toxicity effects must be based on models that
account for a chemical‘s fate in the environment, species exposure, and differences in
toxicological response (likelihood of effects and severity).
The scope and methodology of an LCA differs from that of many approaches adopted for
toxicological assessments in a regulatory context. In LCA it is desirable to account for the full
extent of the likelihood of an effect (recommended midpoint indicator basis) and differences
in severity (recommended endpoint indicator basis).
The basis of comparative risk in LCA accounting for the entire global population of species
is recommended. This must be based on best-estimates complemented with uncertainty
insights. The factors must reflect the likelihood of a toxicological effect integrated over time
and space that is associated with the release of a quantity of chemical into the environment.
This may be zero.
Contributions of emissions to short-term/acute and local scale effects are not typically
addressed in LCAs. The focus here is on the contribution of emissions to the long-term risk
of ecotoxicological effects and associated consequences considering all species habitats and
disperse emissions.
4.9.1.1 Environmental Mechanism (cause-effect chain)
Figure 4-12 shows the cause-effect chain of ecotoxicological impacts and corresponds to
the framework of fate and ecotoxicity effect assessment, as described in the next section.
4 Requirements for specific impact categories 67