Evaluating Circular Footprint Formula

A new study showcases the practical application and performance of the Circular Footprint Formula (CFF)—a key component of the European Commission’s Product Environmental Footprint (PEF) framework—by evaluating the environmental impact of thermomechanically recycled mono‑material polyester carpets. Designed with circularity in mind, mono-material carpets enable true fiber‑to‑fiber recycling, offering a sustainable alternative to conventional multi‑material carpets that typically end up being incinerated. By supporting high-quality recycling loops, this approach aligns directly with the European Union’s ambition to dramatically reduce the environmental footprint of the textile sector and accelerate the transition toward a circular, low-impact economy.

Authors: Sofie Huysman, Jun Yin (Centexbel) & Torun Hammar (RISE Research Institutes of Sweden)

©2026 The International Journal of Life Cycle Assessment

Published within the European tExtended project, the research explores how mono-material polyester carpets—made from a single type of plastic—can be more effectively recycled compared to traditional multi-material carpets. Most conventional carpets are difficult to recycle and are typically burned at the end of their life, contributing to pollution and carbon emissions.

Mono-material carpets, by contrast, are designed for “fiber-to-fiber” recycling, meaning they can be broken down and turned into new carpet fibers. This approach aligns with the circular economy goals promoted by the European Commission.

The researchers evaluated a tool called the Circular Footprint Formula (CFF), part of the EU’s Product Environmental Footprint framework. This method helps measure the environmental impact of products, especially when recycling is involved.

To understand how reliable the CFF is, the team compared it with another common approach used in Environmental Product Declarations (EPDs), known as the “cut-off” or recycled content method.

They applied both methods to three real-world scenarios:

• Recycling mono-material carpets
• Incinerating traditional multi-material carpets
• Incinerating mono-material carpets without recycling

The results were clear on one point: recycling mono-material carpets generally leads to lower environmental impacts than burning them.

However, the study also revealed an important warning. If mono-material carpets are not recycled and are instead incinerated, they can sometimes have an even greater environmental impact than traditional carpets. This highlights how crucial it is to ensure proper recycling systems are in place.

Small parameters, big impact

The study found that certain technical assumptions within the CFF can significantly influence results:

• Market factor: This reflects supply and demand for recycled materials. Changes in this factor alone could shift climate impact results by up to 30%.
• Energy allocation factor: This had a smaller effect on outcomes.
• Yarn thickness: Surprisingly, the thickness of carpet fibers also affected environmental performance, with coarser and finer yarns producing different results.

Improving future sustainability assessments

The researchers conclude that while the CFF is a valuable tool, it needs refinement—especially in how key parameters like market dynamics are determined.

They also stress the need for more detailed environmental data on textiles, particularly regarding product design features like yarn thickness. 

Better data will lead to more accurate and consistent sustainability assessments across the industry.