What is behind one of the key principles of the life cycle assessment (LCA)?
Recycling, a unique stage between two product’s lives
One of the basic principles of a life cycle assessment (LCA) is to cover all the environmental impact for all the life cycle stages of a product or a service. When covering those stages, one can easily find out that the recycling stage is different from all the other stages. Recycling is the last step of one product - the life of a recycled product - but is also the first step of another’s - the life of a product including recycled material.
Being in the middle of two products lives, raises the question of which life the recycling should be attributed? Should we include the recycling step at the end-of-life or at the production?
A negative environmental impact is an environmental benefit
How to account for the recycling step is key for two main reasons. First, the recycling step is a unique because it gives an opportunity to avoid environmental impact. Of course producing 1kg of usable recycled material has an impact (for the transport, the energy consumption at the recycling facility, etc.) but the LCA calculation also considers that 1 kg of virgin does not need to be produced (avoided virgin impact) and the waste that the recycled material is coming from does not need to be treated (avoided elimination impact). Most of the time this results in a "negative" environmental impact of environmental benefit.
Recycled content and recycling rate
Secondly, deciding whether we account the environmental benefit of recycling at production or at end-of-life will have a significative effect on the results because of the difference between R1 (the recycled content) and R2 (the recycling rate).
- The amount of recycled material that a packaging producer will incorporate inside their product is based on the company's strategic decision. This is the recycled content (R1);
- The average share of material that will be recycled at the end-of-life of the product is based on the national waste management system in which the product is sold. This is the recycling rate (R2).
The recycled content and the recycling rate can have very different values, and a significant impact on the environmental benefit that is to be included in the LCA.
What is this A factor ?
Several options are used in the LCA community to allocate the benefits of recycling. They are all derived from 3 main approaches.
- Allocation at the incorporator. The benefits of recycling are allocated to the producers of new products (we integrate the recycling step at the production of our LCA). “There is a high supply of recycled material, let’s encourage the producers so that they add more secondary material to their products!". The results of your LCA will only depend on the recycled content.
- Allocation at the recycler. The benefits of recycling are allocated o the recyclers of used products (we integrate the recycling step at the end-of-life of our LCA). “There is a high demand for recycled material, let’s encourage the recyclers so that they put more secondary material on the marker!”. The results of your LCA will only depend on the recycling rate.
- The shared allocation. The benefits of recycling are allocated to both the producers of new products and the recyclers of used products. An allocation factor is introduced to share the benefits of recycling between production and end-of-life. This is the A factor. The results of your LCA will depend on both the recycled content and the recycling rate.
A "downcycling factor" (noted as the ratio QS/QP), can also be introduced to model a situation where the recycling material replaces the same virgin material, but the amount of saved material is lower than the amount of recycled material due to lower quality.