LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

GROUP 1, SESSION A: ANIMAL PRODUCTION SYSTEMS 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
2. Combined mass and economic allocation
Erik Svanes
Department for Preventive Environmental Research, Ostfold Research, Norway, E-mail:
erik@ostfoldforskning.no
Allocation is a common problem in Life Cycle Assessments. A common allocation situation in food production
occurs when a production line produce one or several co-product(s) and by-product(s). Furthermore the
distinction between waste and by-product is often unclear because although a waste fraction might be given
for free, the transportation of the waste entails costs and the waste can be raw material for products with a
commercial value.
Avoidance of allocation using the decision three given in ISO 14044 can be difficult because the processes
cannot be split, systems expansion is not possible and no causality can be found. Systems expansion is often
difficult because incorporating more functions in a Functional unit is not interesting if the aim is to study one
product and systems expansion through substitution is impractical because a single alternative product cannot
be identified.
Economic and mass allocation have in the past been the most commonly used allocation methods in food
systems but both have their disadvantages. The use of economic allocation can be confusing for consumers,
e.g. because the fact that a product of a high commercial value should have a higher environmental impact
than a low value product coming from the same raw material and the same process is hard to understand.
Mass allocation reflects only physical relationships thus avoiding this problem- One disadvantage of mass
allocation is the fact that byproducts of a low value, e.g. fish skin and bones, carries the same environmental
burden as the main products. The consequence might be that buyers of these by-products might have less
incentive to use this resource. Another problem with mass allocation occurs when a by-product that was
previously given for free to users is being sold instead. The result could be a significant shift in the environmental
burdens from one assessment to another while no physical changes have been made.
One way to avoid the problems associated with these allocation methods is to combine mass and economic
allocation. In the first step economic allocation can be used to distribute environmental impacts between
products of very different usage. In the second step mass allocation is used to distribute impacts between
products of the same usage. The concept has been investigated using two examples. In one example an animal
gives several products going to human consumption, one product going to fertiliser and one to energy
production. In another example carrots are sorted into four main products going to human consumption and
one waste fraction given for free to be used for animal feed. In these examples the above mentioned disadvantages
were avoided. Thus combined allocation proved to a good solution.
ISO 14044 does not seem to preclude such an approach to allocation except maybe the passage that states
that the same allocation procedure should be uniformly applied in the assessment. This could, however, be
interpreted to mean that consistency is required in similar situations, not that one single allocation method is
applied.
References
Schau EM and Fet AM (2008). LCA Studies of Food Products as Background for Environmental Product
Declaration. Int J LCA 13 (3) 255–264.
Ayer N, Tyedmers PH, Pelletier NL, Sonesson U and Scholz A (2007): Co-Product Allocation in Life Cycle
Assessments of Seafood Production Systems: Review of Problems and Strategies. Int J LCA 12 (7) 480–
487.
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