issue 03/2021

Politics
Don’t compare
apples and organges
Using LCA to compare biobased and fossil-based
plastics is not that simple
By:
Constance Ißbrücker
Head of Environmental Affairs
European Bioplastics e.V.
Berlin, Germany
Life cycle assessment
(LCA) has evolved
to be the preferred
tool to assess the
environmental sustainability of certain
products and materials. Recently it has also been
used with great enthusiasm to compare biobased
with fossil-based plastics. It seems to be an easy
instrument to draw conclusions on certain advantages
or disadvantages of both material groups. However, there
are quite some hurdles to overcome if you do not want to
end up comparing apples with oranges again.
There are several aspects to which attention must be
paid in order to guarantee a fair comparative assessment.
Fossil-based plastics have experienced many decades
of continuous, often heavily subsidised, process
improvements, whereas most biobased alternatives are
still at the beginning of their maturity/optimisation curve.
Therefore, comparing fossil-based with biobased plastics
is comparing mature and immature production systems.
Future improvements in terms of feedstock sourcing,
production, conversion, and end-of-life options need to be
considered and assessed by appropriate assumptions and
modelling approaches.
Additionally, it is often assumed that the applied
inventory data of biobased and fossil-based materials are
comparable. That is currently not the case, we have no real
level playing field. Fossil- and biobased plastics datasets
should be brought to the same level of quality in terms of
their completeness, system boundaries, regional scope,
and, of course, transparency.
It is one of the inherent advantages of biobased materials
that they are produced from annually renewable feedstock,
such as corn, sugarcane, or wood. Thus, CO 2
is taken up
from the atmosphere, and the biogenic carbon is locked
up in the biobased product. At the product’s end of life (i.e.
when it can no longer be recycled), the carbon re-enters
the natural carbon cycle via incineration or composting,
thereby closing the material carbon loop.
Biobased plastics are independent of fossil resources
and do not contribute to harmful environmental effects
connected with the
exploitation of fossil raw
materials such as crude
oil. Effects of the latter
are, interestingly, hardly
considered in LCA data modelling. In contrast to
certain possible negative indirect effects connected
with the sourcing of renewable feedstock. No doubt, it
can make sense to look at factors such as ILUC (indirect
land-use change) and gain additional information on this
subject. However, for the sake of fair play, indirect effects
caused by fossil-absed materials and their production
need to be considered as well. Furthermore, LCAs should
not only focus on the negative impacts but also account
for indirect positive impacts, especially where these are of
high relevance to a functioning circular economy (e.g. the
beneficial effects on biowaste collection by using industrial
compostable bio-waste bags).
Biobased plastics offer multiple end-of-life options,
depending on the material chosen and the application at
hand. For example, biobased drop-ins (e.g. bio-PE or bio-
PET) can be mechanically recycled in the existing recovery
streams. Industrially compostable materials that are
certified in line with EN 13432 can be recovered through
organic recycling. Any selected end-of-life option needs to
be material and product-specific and reflect reality.
Whatever impact categories are considered in a
comparative LCA of fossil- and biobased materials, a
transparent and acknowledged methodology (like ISO
14040/44, or PEF methodology) must be the basis, without
neglecting stakeholder involvement. In the end, the
interpretation of the results is a crucial aspect and can,
when done frivolously, be harmful to the whole bioplastics
sector. Especially in a policy context, proper communication
of LCA outcomes is of high importance and should show the
necessary sensitivity and expertise.
For more information on this topic please also read the
EUBP Position Paper [1].
[1] “Sound LCA as basis for policy information”
www.european-bioplastics.org
26 bioplastics MAGAZINE [03/21] Vol. 16