Aseptic Packaging: Why Items like Milk Cartons Are Difficult to Recycle

Aseptic carton packaging is a well-accepted technique for the preservation of liquid and particulate foods and has revolutionized the shelf life and shipping efficiencies. While this type of packaging offers many advantages for the consumer and the manufacturer, it presents challenges for recycling.

Aseptic Carton Packaging Benefits

When looking at NPR’s article, In The Recycling World, Why Are Some Cartons Such A Problem?, we see that there are a number of environmental benefits to aseptic cartons. Due to its ability to preserve food for longer, its simple shape allows is for higher volumes of transport and capacity to preserve without refrigeration (until opened), and is lightweight; aseptic packaging is a powerhouse when it comes to modern advancements in food packaging.

“Lightweight packaging requires less energy to ship than heavier material (less carbon footprint). The packaging versus product ratio — seemingly the packaging industry’s analog of dress measurements — is only 7 percent packaging to 93 percent product by weight. In comparison, a steel can’s ratio is 13 percent packaging to 87 percent product.”

Aseptic Carton Packaging and its Relation to Recycling

While many envision the classic house shaped milk carton as the poster child for recycling; creation of the packaging complicates the relationship between well-known recyclable materials and trash materials. Because of the multiple layers of the several types of materials (i.e: paper, plastic, and aluminum foil) bound with adhesive, it makes these products difficult to recycle. Many recycling service providers do not have the capacity or the technology to properly sort these materials, or the markets to sell them, which limits the recycling options. For facilities that do accept these types of cartons to be recycled, they will be separated by a certain process called hydropulping at the recycling facility. This process separates the paper layer from the aluminum foil and the outer plastic layers and is then recycled and used for other purposes.

Source: In Love with All Things Tetra Pak – all things GUD!

Hydropulping is the state-of-the-art process to separate paperboard from LPB multilayers, reducing the cellulose content to less than 5% (Georgiopoulou et al., 2021; Zawadiak, 2017)

Types of Aseptic Cartons

Aseptic packaging comes in two main types of cartons: Shelf-stable and refrigerated cartons.

As the name suggests, self-stable cartons do not require refrigeration until the product is opened whereas refrigerated cartons are meant to always be stored within the fridge unless in use.

These products generally come within two distinct shapes: rectangular and gable topped (the roofed rectangle, triangular topped cartons).




Rectangular Packaging Source: About Cartons (    




Gable Topped Packaging Source: About Cartons (

According to the Carton Council’s findings on aseptic packaging, about 74% paper, 22% polyethylene, and 4% aluminum, go into shelf stable packaging compared to its refrigerated counterpart; being made of 80% paper and 20% pol

How to Spot Aseptic Packaging:

Generally, the look of aseptic packaging has a smooth and glossy exterior with a shiny metallic lining on the inside. According to the askUSDA website, various juices, vegetable products, soups, tofu, wines, liquid eggs, whipping cream, and teas also use aseptic packaging. These materials are often rectangular in shape and are also referred to as Tetra Pak Packaging, which has the following logo on the bottom of their cartons:




Recycle or Not to Recycle?

The more informed you are about what the materials are made of can help to determine what goes where. Due to the inconsistent nature of what can and cannot be recycled, it is important to understand your local recycling/disposal guidelines.

For residents of West Contra Costa County be sure to:

  • Identify what is aseptic packaging; and
  • Depending on where you reside*, this type of item will be accepted in recycling or will need to be placed in the trash.

* For residents in the rest of West Contra Costa County (customers of Republic Services), place these types of items in your curbside trash bin. For residents of El Cerrito, these items are accepted in your curbside recycling containers, preferably rinsed and dried. Cartons are recommended not to be flattened to ensure that the sorting machines are able to properly sort the materials. Sorting facilities have machinery that can register three-dimensional shapes that increases its chances of being sorted properly.


For more information and to determine these items and other items of what goes where, refer to the RecycleMore Online Recycling/Disposal Guide