Pertex® Quantum Air: Moving from C6 to C0 DWR

From Fall/Winter 2025, we’re switching the DWR finish on Pertex Quantum Air used in the Light Alpha Vest/Jacket, Alpha Anorak, and Light Alpha Only Hood from C6 to C0.

The change reduces the environmental impact of the finish, but during testing and production we also found greater variation in the fabric’s air permeability than with the previous C6 treatment.

Here, we’d like to explain what changed, what we found through testing, and how we’re handling products that fall below our usual benchmark

The former C6 DWR finish contains small amounts of perfluoroalkyl substances (PFAS), which are resistant to degradation in nature and can persist for long periods in soil and other environments. C0 DWR, on the other hand, does not use PFAS and therefore has a lower environmental impact.

However, compared with C6 DWR, the C0 treatment tends to penetrate deeper into the fabric, which can lead to variations in air permeability and perceived wind resistance.

Although our prototypes showed sufficient breathability, air permeability measurements taken during production revealed noticeable differences between color batches.

Through this testing, we confirmed that Pertex Quantum Air treated with C0 DWR may show some variation in breathability from product to product.

Based on the Pertex Quantum Air used in the first-generation Alpha Anorak—which had an air permeability of 33 cc/cm²·s—we set our internal benchmark at 33 cc/cm²·s or higher, as this level provides a strong balance of breathability and warmth.

Fabrics that fall below this benchmark are sold separately at a 20% discount.

Even so, these lower-rated fabrics still average 26.5 cc/cm²·s, which is generally considered highly breathable. The lower air permeability also means slightly more warmth. While this falls outside our intended balance of breathability and warmth, it may suit hikers who tend to run cold or expect to use the jacket primarily in colder conditions.

This change has also shown us how difficult it can be to balance environmental considerations with consistent performance.

We’ll continue testing and evaluating materials carefully, looking closely at how they perform in real use and making choices that we believe work best on the trail.