Page 129 - Materials Chemistry, Second Edition

114 A. Bjørn et al.

rules on evaluating inputs, and outputs and impact assessment. Any differences
between systems regarding these parameters shall be identified and reported”.
When a comparative study is intended to conclude on the superiority or equivalence
of the compared alternatives in terms of their environmental performance, and to
make these conclusions publically available, the standard identifies it as a “com-
parative assertion intended to be disclosed to the public”. For such applications of
LCA, the standard requires that these points shall be evaluated in a critical review
performed by a panel of interested parties (see Sect. 8.10 and Chap. 13).
These special requirements reflect the consequences that the comparative use of
LCA results may have for other companies, institutions and stakeholders that are
not directly involved in the study and they are intended to prevent the misuse of
LCA in market competition.
To prevent misleading LCA results and the misuse of LCA in comparative
assertions, the ILCD guideline furthermore requires that:
• The uncertainties involved must be evaluated and communicated when one
product system appears to have a lower environmental impact for one or more
impact categories than another, see Chaps. 11 and 12 for details.
• In the case where the goal definition prescribes a comparison based on a single
indicator (e.g. carbon footprint) the LCA study must highlight that the com-
parison is not suitable to identify environmental preferable alternatives, as it
only covers the considered impact(s) (e.g. climate change). This applies unless it
can be sufficiently demonstrated that the compared alternatives do not differ in
other relevant environmental impacts to a degree that would change the con-
clusions of the comparison if those other impacts would be included in the
analysis. Such demonstrations may be in the form of other LCA studies avail-
able for sufficiently similar systems.

8.10 Need for Critical Review

A critical review is performed by experts not involved in making a study. A critical
review is sometimes required (e.g. for studies with the intended publication of
results), but even when there is no formal requirement a critical review is useful for
improving the quality and credibility of a study.
Chapter 13 deals specifically with the critical review stage of an LCA, presents
the different types of critical review and explains for what kind of LCA studies
(with reference to the goal definition) these are needed. It is, however, useful
already during the scope definition to decide whether a critical review is needed or
intended. If a review is required or intended, the scope definition should further-
more specify the form of the review in order to allow the documentation and
reporting of the study to be tailored to meet the later requirements from the peer
reviewers. It should also, in the scope definition, be decided whether the review
should be performed on the final draft of the LCA report or whether it should be