PFAS in Trail Running Shoes: Safe Off-Road Footwear

Trail running shoes are one of the sneakiest places PFAS hide in your closet. I had cleaned up my kitchen, ditched my old rain jacket, and felt pretty good about our family’s progress before I realized I was still lacing up shoes coated in forever chemicals every weekend. Trail shoes are built for mud, rain, creek crossings, and general outdoor chaos, so manufacturers have long relied on PFAS-based DWR (durable water repellent) coatings to keep them performing in wet conditions. If you have been on a similar clean-up journey, your trail shoes deserve a closer look. The good news: several brands now use fluorine-free alternatives that hold up just as well on the trail.

What’s Inside

• Why trail shoes are more likely to contain PFAS
• The science behind the concern
• How to find PFAS-free trail shoes
• PFAS-free trail running shoes to consider
• Tips for trail runners going PFAS-free

Why trail shoes are more likely to contain PFAS

The short answer: trail shoes need to handle wet, muddy, unpredictable conditions. Manufacturers add water-repellent coatings to the upper mesh, tongue, and sometimes the lining. For decades, the go-to treatment was PFAS-based DWR, a fluorinated coating that makes water bead up and roll right off.

A 2022 study published in Environmental Science and Technology found that PFAS from DWR-treated textiles migrate during normal wear and washing. Trail shoes get even more exposure than jackets because they are regularly soaked in sweat, submerged in puddles, and baked in the sun to dry, all of which accelerate the release of fluorinated compounds.

Road running shoes are less likely to carry heavy DWR treatments because they are not marketed for wet conditions. But trail shoes, especially anything labeled “waterproof,” “all-weather,” or “water-resistant,” have traditionally been treated with PFAS-based chemistry.

The science behind the concern

PFAS earned the name “forever chemicals” because they do not break down, not in the environment, not in your body. Studies have linked PFAS exposure to thyroid disruption, immune suppression, elevated cholesterol, and developmental concerns in children. Yes, the dose from a single pair of trail shoes is small compared to contaminated drinking water. But your body does not care where it comes from. It all adds up.

For trail runners who spend hours on the trail in wet conditions, the warm, moisture-rich environment inside a shoe creates an efficient pathway for chemical migration from treated fabrics into the skin. Kids who run cross-country or play sports in treated footwear face an even higher relative exposure because of their smaller body weight.

Here is the part that keeps me motivated: once you stop the exposure, PFAS do slowly clear from your body. Switching your trail shoes is one of the easier swaps, and it is especially worth doing if you log a lot of miles or have kids running cross-country.

How to find PFAS-free trail shoes

This used to be hard. It is not anymore. Several major brands have dropped PFAS entirely, and finding a clean pair of trail shoes is way easier than it was even two years ago.

Look for these certifications: OEKO-TEX Standard 100 and bluesign both restrict PFAS in certified products. If a trail shoe carries either certification, the materials have been tested and verified.

Brands that have gone PFAS-free: KEEN removed intentionally added PFAS from its entire footwear line in 2018 and publishes chemical transparency data. Brooks has stated its shoes are PFAS-free. Allbirds uses a fluorine-free C-Zero DWR on its waterproof models. Newer GORE-TEX ePE (expanded polyethylene) membranes are also made without intentionally added PFAS, though older GORE-TEX ePTFE models still use fluoropolymers.

Watch for red flags: Any trail shoe marketed as “waterproof” or “water-resistant” without specifying the type of treatment should be questioned. A quick email to the brand asking about fluorinated DWR treatments will usually get a clear answer.

Check the database: The PFAS Free Life Database maintains verified listings across product categories, including footwear, so you can search before you shop.

PFAS-free trail running shoes to consider

Here are the trail-ready options I recommend, all from brands that have publicly committed to removing PFAS:

1. KEEN Targhee III Waterproof Hiking Shoe (Men’s) - KEEN was one of the first major footwear brands to go PFAS-free, removing intentionally added PFAS across its entire line in 2018. The Targhee III uses KEEN.DRY fluorine-free waterproof membrane and has an aggressive outsole built for trail running and light hiking.

   

2. Brooks Ghost 17 Men’s Running Shoe - Brooks has stated its running shoes are made without PFAS. While the Ghost 17 is a road shoe, its DNA LOFT v2 cushioning makes it a great PFAS-free option for runners who train on mixed surfaces or groomed trails.

   

3. adidas Adizero Evo SL Running Shoe - Listed as PFAS-free per brand, the Adizero line features Lightstrike Pro cushioning and a lightweight build. adidas has committed to phasing out PFAS across its product range, making this a clean pick for speed-focused trail-to-road runners.

   

Tips for trail runners going PFAS-free

Do not spray your shoes. Many aftermarket waterproofing sprays use PFAS-based chemistry. If you want water resistance, buy a shoe with fluorine-free DWR from the factory. Spraying chemicals onto your shoes defeats the purpose of choosing a clean pair.

Let wet shoes air-dry. Avoid tossing trail shoes in the dryer. Heat can increase off-gassing from any residual treatments. Stuff them with newspaper and let them dry at room temperature.

Replace at end of life. Running shoes typically last 300 to 500 miles. When your current trail shoes wear out, choose a PFAS-free replacement rather than re-buying the same treated model. This gradual approach makes the transition easy and affordable.

Wash mindfully. If your shoes do have a DWR coating, machine washing can release PFAS into the water supply. Spot-clean with a damp cloth or brush instead, and keep in mind that PFAS from treated textiles also enter waterways through washing machines.

Check your kids’ gear too. Youth cross-country spikes and soccer cleats are often treated with the same coatings as adult shoes. Brands like KEEN offer PFAS-free options in youth sizes, so the whole family can make the switch.

If you want to keep going with swaps beyond footwear, we have guides to PFAS-free waterproof jackets, PFAS-free rain pants, and PFAS-free hiking shorts. The PFAS Free Life Database also has verified listings across hundreds of product categories.

Frequently Asked Questions

Are PFAS-free trail shoes as waterproof as treated ones?

Fluorine-free DWR treatments have improved significantly and work well for everyday trail conditions, including rain, puddles, and muddy terrain. They may not last as many wash cycles as PFAS-based DWR before needing reapplication, but for the vast majority of trail runners, the performance difference is negligible. Brands like KEEN have used fluorine-free waterproofing since 2018 without reports of performance issues.

What health risks are linked to PFAS in trail running shoes?

PFAS exposure from consumer products has been associated with elevated cholesterol, immune suppression, hormone disruption, and increased cancer risk with certain exposures. Children and pregnant women are considered especially vulnerable because of higher absorption rates relative to body weight. Reducing exposure through product swaps can lower your body burden over time, since PFAS do eventually clear from the body when new exposure stops.

How can I tell if my current trail shoes have PFAS?

Check the product description for terms like “DWR,” “water-repellent,” “stain-resistant,” or “waterproof.” If any of those appear without a specific mention of “fluorine-free” or “PFAS-free” treatment, there is a reasonable chance the shoe uses a PFAS-based coating. You can contact the brand directly to ask, or search the PFAS Free Life Database for verified listings.

*Research references: Environmental Science & Technology 2022

eBioMedicine 2021

KEEN Detox Program*