“Key factors: preform weights and the use of recycled materials” – Criteria on life cycle assessments of PET bottles
Benedikt Kauertz, Scientific Director of Industry & Products at the Ifeu – Institute for Energy and Environmental Research in Heidelberg, Germany, is an expert on environmental assessments of packaging and life cycle assessments of beverage packaging. In an interview with PETplanet, he delves into the crucial elements for a favourable evaluation of PET bottles, key factors for further optimisation, and the current challenges hindering the establishment of PET reusable systems.
PETplanet: Mr Kauertz, you are engaged in the life cycle assessment (LCA) of packaging. What is your perspective on PET bottles?
Kauertz: For over 15 years, I have been professionally involved in the environmental assessment of packaging and have conducted numerous studies on beverage containers during this time. Therefore, I primarily approach this subject from a technical standpoint. I am well acquainted with the advantages of packaging, as well as its drawbacks and the challenges involved in optimisation. Based on the findings of these studies, we observe that the selection of beverage packaging should primarily be influenced by the consumption scenario. When the requirements lean towards lightweight and high stability, and there exists a seamless possibility to support recycling loops or return the bottle for refill after use, PET bottles emerge as sensible beverage packaging solutions.
PETplanet: How have the life cycle assessments of PET bottles evolved over recent years, and what are the key factors involved in a positive evaluation?
Kauertz: Here, we must differentiate between single-use and refillable bottles. For both systems, the key factors are the preform weights and the percentage of recycled material used. While these aspects are more critical for single-use bottles, refillable bottles also benefit from them. In the case of single-use bottles, we also observe that separate collection and material recycling with the aim of reintroducing the material into new bottles have a significantly positive impact on the life cycle assessment. For refillable bottles, increasing the reuse rate is similarly crucial.
Systems that have invested in the development of these key factors in recent years have significantly improved their LCA performance. Given that major market players in Europe have also embraced this path, the average life cycle assessment of PET single-use and refillable systems is certainly more positive today than it was ten years ago. However, we must not forget that there are still outliers in both systems that have implemented few optimisations so far. It is essential to create conditions that encourage all stakeholders to implement at least some form of optimisation for their bottle systems in the future.
PETplanet: Despite many efforts by the industry to improve bottles, whether through weight reduction, the use of recycled materials, or “design for recycling” aspects, PET bottles overall do not fare well in public perception. What do you think is the reason for this?
Kauertz: One reason is the aforementioned outliers. Every bottle that is visibly not optimised or, worse yet, ends up in the environment, serves as evidence that the industry’s efforts are not yielding sufficient results. In general, plastic packaging currently has a negative image, primarily due to issues with littering, especially marine littering. Although these problems are much more apparent in other parts of the world than they are here, in Europe, there is a perceived need to limit the amount of plastic packaging. This mindset involves not only ensuring order within our own homes but also concerns about exacerbating issues through waste exports to Asia.
PETplanet: Last year, the Schwarz Group [Lidl, Kauf-land] in the German-speaking region made a bold move by informing the public about their in-house circular system for PET bottles through television commercials, which caused quite a stir. Prior to this, the Schwarz Group had commissioned a study from you, using the data to substantiate their campaign. How did you experience the ensuing discussion?
Kauertz: From our perspective, the discussion surrounding the study itself was surprisingly rational. Many of the criticisms raised, such as those regarding the data points concerning refillable bottles, had already been thoroughly addressed in the study text. Therefore, for stakeholders genuinely interested in a reasoned discussion, these concerns were easily resolved.
PETplanet: One criticism, voiced by the German Federal Environment Agency, was that the Schwarz Group claimed to operate without using virgin PET, stating: “However, on a larger scale, someone must use fresh material to offset the losses.” How would the material loss in recycling be balanced?
Kauertz: In fact, the Schwarz Group does not rely on virgin PET for the production of the analysed containers. We verified this during the study’s development by examining documents. Certainly, there are material losses in the collection and processing of used PET single-use bottles, and we have accounted for these losses in the LCA. The study explicitly states at the outset that it examined the Schwarz Group’s circular system. If the Federal Environment Agency takes this into account, it might clarify its statement and focus on the overall market. Then, the statement would be accurate in acknowledging that not all bottles can always consist of 100% rPET if the market is not to shrink. The average rPET content in Germany is still below 50%. There is still plenty of room for improvement, and much material flows into non-recyclable applications, lost to the circular economy. Therefore, there is ample “space” for other highly optimised PET bottles. In the long term, an average rPET content of up to 90% should be achievable if the material can be kept within the bottle cycle. This is also demonstrated by another study published last year by GVM on behalf of Coca-Cola.
PETplanet: You yourself point out in your study that the system optimised by the Schwarz Group with 100% rPET cannot represent the entire industry. How does a bottle with a 25% rPET content, as will be mandatory on average in the EU next year, compare?
Kauertz: Primary material production is one of the key drivers of the life-cycle assessment of PET bottles. Therefore, all relevant factors such as weight reduction, the use of secondary materials, or the reuse of containers impact this stage of the lifecycle. Reducing the secondary material content from 100% to 25% introduces significant environmental burdens.
PETplanet: How do you assess the market development regarding the availability of rPET for the bottling sector?
Kauertz: We hear different statements on this matter. Actors who have focused on long-term partnerships and high integration levels across the entire value chain in their procurement strategy seem to have fewer issues with material sourcing than others. Fundamentally, we observe significant competition for secondary materials among various sectors. The textile industry, for instance, has substantial demand for rPET and can offer higher prices. From a LCA perspective, we always advocate that the material should go where it has the highest probability of being recycled again.
PETplanet: In many countries, there is an ongoing debate about the viability of a mandatory reusable quota, such as the one preferred by the EU Commission. Under what circumstances is PET reusable packaging environmentally sensible?
Kauertz: Reusable packaging is always sensible where we have established supplier and customer relationships that reliably function, and where the structures for these systems are therefore sensibly established. The greatest challenges in the way reusable systems operate in the beverage sector today are the individualisation of bottles and the separation of containers during sale and return. All of this leads to high sorting efforts and additional exchange trips, which can quickly counteract the benefits of resource-efficient material handling. A creative approach to the advantages and possibilities of PET bottles can offer advantages over glass reusable systems. I am confident that we will see meaningful PET reusable concepts in the future.
However, this is also the weak point of a mandatory reusable quota. Who guarantees that sensibly optimised systems will enter the market? The focus should therefore be more on evaluating what makes reusable and single-use options life cycle-optimised and then addressing these factors through regulation.
PETplanet: Finally, a word on other packaging materials. Glass, cardboard, cans, PET – ultimately, does every advantage and disadvantage hinge on the transportation route?
Kauertz: Ideally, transportation routes are always short, and transportation vehicles are consistently fully utilised. In general, the heavier the packaging material, the more significant the impact of transportation. However, life cycle assessments are highly complex models. Relying solely on one factor in the system, such as transportation or recyclability, typically oversimplifies the issue and can, in the worst case scenario, lead to incorrect conclusions.
PETplanet: Thank you very much, Mr Kauertz!
