What is the “barrier layer’’ in aseptic cartons?
An aseptic carton package consists of several layers of materials that perform different functions. This includes paperboard, which serves as the base material for the packaging, and polymer layers that, among other things, protect against outside moisture.
The barrier is traditionally a very thin layer composed of aluminium foil – thinner, in fact, than the width of a human hair. As the name suggests, it plays a vital role in keeping out light and oxygen. This is necessary for keeping perishable food safe without refrigeration for periods of several months.
On average, paperboard already accounts for around 70% of the materials used in our aseptic cartons. Plant-based polymers are also increasingly helping to increase the share of low-carbon renewable materials in these packages. While the properties of aluminium provide an excellent source of protection against oxygen and light, we are constantly looking for ways to further improve the environmental performance of our packaging solutions. Developing an alternative to this layer using other materials has therefore been a key priority.
What do you mean by “paper-based” barrier?
In an effort to maximise the paper and renewable content in our aseptic carton packaging, we have developed a paper-based barrier solution capable of replacing the traditional aluminium foil barrier layer.
The paper-based barrier is an innovative material that consists of a paper-based protective layer featuring an ultra-thin, nanometre metalised coating. Together with other layers in the packaging it protects against oxygen, light, moisture and bacteria. This enables the paper-based barrier to deliver uncompromised food safety and a comparable shelf life to traditional aseptic cartons with an aluminium foil barrier1. In doing so, together with plant-based polymers, the paper-based barrier enables a reduction in the carbon footprint of an aseptic package by 43%2 compared to traditional aseptic carton packages with an aluminium foil layer and fossil-based polymers.
What benefits does this paper-based barrier offer over traditional aseptic carton packaging solutions?
Tetra Pak is on a journey to maximise the share of paper content and simplify the packaging material structure of our packaging solutions and thereby reduce the overall environmental footprint of every food and beverage package produced. For aseptic cartons, a paper-based barrier brings a number of key sustainability advantages. Most recently, in December 2025 the first-ever use of this technology with juice packaging took place in Spain, and showed the following results:
- Increase in paper content of the aseptic carton: the volume of FSC™-certified paper content3 in the package was increased to approximately 80%.
- Maximising renewability: an increase in total content of renewable materials in the carton to 92% by combining the paper-based barrier with plant-based polymers derived from sugarcane for the coatings of the packaging material.
- Cutting the carbon footprint of the package: by replacing the traditional aluminium foil layer with a paper-based barrier, combined with the use of plant-based polymers derived from sugarcane in the packaging material coatings, emissions were reduced by as much as 43%.4
What does the paper-based barrier mean from a recycling perspective?
According to both internal and external tests we have conducted on cartons with the paper-based barrier, the new solution has proven to be as compliant as current Tetra Brik® Aseptic cartons with current recycling streams. This means that aseptic beverage cartons with the paper-based barrier can be collected, sorted and recycled in the same way as other Tetra Pak® cartons, where adequate collection, sorting and recycling infrastructures are in place, at scale.
Simplifying the material structure of the carton from 3 to just 2 main materials – paper and polymers – the paper-based barrier increases the paper content of the packaging solution. This represents an opportunity for recycling infrastructures where the quality and recovery efficiency of materials is key. Specifically, cartons with a higher paper yield are more attractive to recycling mills.
What is the renewable content of a carton with the paper-based barrier?
Tetra Pak is committed to investing in the development of packages that are made with a simplified material structure and increased renewable content. Compared to traditional aseptic cartons, those with a paper-based barrier increase the paper content to approximately 80%5.
At the same time, the package features polymers as part of its structure in order to protect the filled product from external moisture. We have worked to maximise the renewable content in our carton packages, for example by using polymers derived from sugarcane for the packaging material coatings. Combining these renewable polymers with the paper-based barrier, it is possible to increase the share of renewable materials up to 92%.
We believe that this type of packaging solution can help the industry address some of the most pressing environmental challenges it faces. These include global warming, climate change and food waste, which score among the top environmental concerns for consumers6. Through continued development, our aim is to further increase the share of renewable and recycled materials and reduce the carbon footprint of our packaging solutions, while simultaneously ensuring food safety and quality to improve global food access.
What types of food and beverage products can use aseptic packaging with a paper-based barrier?
Validation of the paper-based barrier concept has so far focused on packages for liquid dairy and juice products distributed under ambient conditions. The results have shown that the solution can provide comparable shelf-life and protection from oxygen and light compared to traditional aseptic cartons with an aluminium foil layer.7
We are continuing to study material characteristics in search of future packaging improvements, including interaction with other filled products and formulations. To leverage the benefits of the paper-based barrier across our aseptic packaging portfolio, we will keep up the pace of innovation. In the coming years we will bring the same high level of food protection and shelf-life to many more packaging solutions and filled products. We will upgrade sealing technologies, openings and closures too, while developing and industrialising the packaging material for widescale implementation.
Why is Tetra Pak focusing on a paper-based barrier alternative rather than other materials?
In a transition towards a circular economy, it’s crucial that we shift from energy-intensive, high-carbon, fossil-based packaging materials to low-carbon, renewable ones. This will help us to ensure that ambient distribution can continue to provide the long shelf-life without refrigeration that is so critical to food safety and availability, without draining our planet’s resources.
Of course, Tetra Pak has always believed in the power of paper. The high share of paperboard in our cartons today is what gives them a lower carbon footprint than other packaging options in the dairy and JNSD segments.8 Scoring high on ease of flattening for disposal, recyclability, and renewability, carton packages are seen as the most environmentally sound solution for food and beverages.9 Furthermore, they have the strength, rigidity and robustness to protect aseptic products throughout their extended life cycles.
Leveraging all of these benefits, the paper-based barrier also leads to a simplified material structure which paves the way to further benefits downstream for paper mills and recyclers.
This is part of our long-term ambition to developing the world’s most sustainable food package.10 Creating this future food package requires multiple testing phases in collaboration with customers, suppliers, and partners on our journey to transform food systems. We remain fully committed towards this goal, addressing all challenges, one step at a time.
What will the development of a paper-based barrier mean for existing filling and packaging lines?
Traditionally, aseptic packaging lines rely on the presence of the aluminium foil layer to perform the sealing of the carton packages. In the current paper-based barrier solutions launched in Portugal and Spain, the Tetra Pak® A3/Compact Flex sealing system was rebuilt to replace the induction heating with ultrasonic sealing technology. We are in the process of developing technical solutions that will enable packaging material with the paper-based barrier to run across our current and future equipment portfolio. This will be a crucial part of our continued innovation journey going forward.
What are the next steps in the development of the paper-based barrier?
To further enhance the environmental profile of food cartons, Tetra Pak is investing up to €100 million over the next decade. This includes the research and development of packages made with a simplified material structure and increased renewable content. Our work to innovate the paper-based barrier for aseptic cartons has been a key part of this effort.
We are now moving into a phase where we will validate the industrial set-up to support growth in the volume of available aseptic cartons with the paper-based barrier. Development is also continuing to expand the available food and beverage product categories that can take advantage of this material innovation.
1 An external technology validation performed in 2023, confirmed a shelf-life of 6 to 9 months for LDP (this value would vary depending on specific product formulation).
2 Source: Carbon Trust-verified Tetra Pak ‘Carton CO2 Calculator’ model version 11 (valid from 2025-01-01). Scope: cradle-to-grave measurement of a Tetra Brik® Aseptic 200 Slim Leaf carton with plant-based polymers in coating and paper-based barrier for juice compared to a Tetra Brik® Aseptic 200 Slim Leaf package with aluminium foil layer and fossil-based polymers. Geography: EU Industry data.
3 All paperboard in Tetra Pak® packages comes from sustainably managed and deforestation-free areas, as certified by the Forest Stewardship Council™. Learn more: https://www.tetrapak.com/sustainability/focus-areas/biodiversity-and-nature/responsible-sourcing/paperboard
4 Source: Carbon Trust-verified Tetra Pak ‘Carton CO2 Calculator’ model version 11 (valid from 2025-01-01). Scope: cradle-to-grave measurement of a Tetra Brik® Aseptic 200 Slim Leaf carton with plant-based polymers in coating and paper-based barrier for juice compared to a Tetra Brik® Aseptic 200 Slim Leaf package with aluminium foil layer and fossil-based polymers. Geography: EU Industry data.
5 Considering a Tetra Brik® Aseptic 200 Slim Leaf package.
6 Tetra Pak® Sustainable Packaging Consumer Research 2025, comprising a total of 12,500+ consumer interviews based on an online questionnaire in 25 countries.
7 Maximum shelf-life is dependent on the specific product formulation, distribution conditions, and customer requirements.
8 Source: ifeu 2020, “Comparative Life Cycle Assessment of Tetra Pak® carton packages and alternative packaging systems for beverages and liquid food on the European market."
9 Tetra Pak® Sustainable Packaging Consumer Research 2025, comprising a total of 12,500+ consumer interviews based on an online questionnaire in 25 countries.
10 This means creating cartons that are fully made of renewable or recycled materials, that are responsibly sourced, therefore helping to protect and restore our planet's climate, resources and biodiversity; contributing towards low carbon production and distribution; are convenient and safe, therefore helping to enable a resilient food system; are fully recyclable.