PFAS in Hiking Pants, Where Only the Untreated Pairs Pass

Ten of the fifteen hiking pants we graded score 20 out of 100. The two best are the two with no water-repellent finish on them, and both are Columbia, which also has five pairs in the bottom tier. Between them sit three Patagonia pairs at 45, still DWR-treated, lifted by Patagonia's statement that 100% of its new products from Spring 2025 are made without intentionally added PFAS, which we have not verified.

One product names the chemistry outright. The Fjällräven Keb GTX Waterproof Shell Trousers are recorded as a GORE-TEX laminate membrane, polytetrafluoroethylene. PTFE is the fluoropolymer at the center of this entire subject, and it is stated rather than inferred.

Summary comparison table

Product	PFAS grade	Verdict
Columbia Women's All Seasons Pull-On Pants	Good, 65/100	Nylon and polyester knit, no water treatment stated
Columbia Men's Stealth Spring Chino Pants	Good, 65/100	Cotton blend twill with no water-repellent finish
Patagonia Men's Outdoor Everyday Pants	Poor, 45/100	Nylon blend with a DWR finish
Patagonia Men's Terravia Trail Pants	Poor, 45/100	Nylon and polyester with a DWR treatment
Patagonia Men's Houdini Rock Climbing Pants	Poor, 45/100	Nylon with a DWR finish
Columbia Men's Silver Ridge Convertible Pants	Bad, 20/100	Nylon and polyester with a DWR treatment
Columbia Men's Silver Ridge Utility Pants	Bad, 20/100	Nylon blend with a DWR finish
Columbia Men's Pitchstone Outdoor Pants	Bad, 20/100	Nylon with a DWR water-repellent finish
The North Face Men's Basin Pants	Bad, 20/100	Nylon and polyester with a DWR treatment
The North Face Men's Sprag 5-Pocket Pants	Bad, 20/100	Cotton and nylon blend with a DWR finish
Fjällräven Abisko Hike Trousers	Bad, 20/100	G-1000 HeavyDuty, polyester and cotton
Fjällräven Abisko Lite Trekking Trousers	Bad, 20/100	G-1000, polyester and cotton
Fjällräven Keb GTX Waterproof Shell Trousers	Bad, 20/100	GORE-TEX laminate, recorded as polytetrafluoroethylene

How we graded these

Every grade in this article is a model-based estimate built from publicly available materials disclosures and brand documentation, not a lab test performed by our team. A high score means lower concern based on reviewed sources, never PFAS-free and never safe. No product in this category carried published independent lab data. The recorded concerns were PFAS in a DWR finish, DWR coating degradation with microfiber shedding, and microplastic shedding from synthetic fibers during laundering. You can compare any specific pair using our PFAS product finder.

The one product that names it

Almost every low grade on this site rests on something a manufacturer did not say. This one does not. The Keb GTX trousers are a GORE-TEX shell, and GORE-TEX membrane is expanded polytetrafluoroethylene, which our record states plainly.

Being fair about what that means, a PTFE membrane is a solid fluoropolymer laminated between fabric layers, not a loose surface treatment, and the industry argument has long been that a bonded membrane behaves differently from a sprayed finish. Our model does not make that distinction, and we are not going to pretend we have tested it. What we can say is that this is the one garment here where the fluoropolymer is named rather than inferred, and a reader deserves that stated rather than buried in a tier.

Worth knowing separately, GORE-TEX has been moving parts of its range to non-fluorinated membranes. Where a specific garment uses one and says so, it would grade differently. This one is recorded as PTFE.

Columbia at both ends

Columbia is the useful brand to study because it sells both kinds. Its Stealth Spring Chino is cotton blend twill with no water-repellent finish and grades 65. Its Silver Ridge Convertible, the classic zip-off hiking trouser, carries a DWR treatment and grades 20.

Same brand, same shelf, 45 points apart. The separator is not quality or price, it is whether the fabric was finished to shed water. That is also the feature most people are buying hiking trousers for, which is the uncomfortable part.

Patagonia at 45

The Patagonia Men's Outdoor Everyday Pants, Terravia Trail Pants and Houdini Rock Climbing Pants all carry a DWR finish, which our model counts as a water-repellent treatment. They grade 25 points above the other treated pairs because Patagonia says 100% of its new products from Spring 2025 are made without intentionally added PFAS. That earns a brand claim credit and removes the penalty for saying nothing about PFAS. It is Patagonia's own statement, not a test or a certification, and it covers new products, so older stock may predate it. An earlier version of this guide put these pairs at 20, and we updated it on 17 September 2026.

The Fjällräven case, which is different again

Two of the three Fjällräven entries are G-1000 trousers, the Abisko Hike and Abisko Lite. According to Fjällräven, G-1000 is a polyester and cotton fabric made water and wind resistant with Greenland Wax, which the brand describes as a mix of beeswax and paraffin, and most G-1000 garments come pre-waxed.

Our records for these two trousers count a water-repellent treatment without naming what it is, so they grade 20 alongside the rest. If the treatment on a given pair is Greenland Wax, that is a named wax rather than a fluorochemical, and our model scores a named, non-fluorinated coating far more gently than an unnamed one. We have not changed the grade on that basis, because our record does not say it. We are telling you so that you can check the product yourself.

If you want water resistance you can see and reapply, G-1000 with a wax you apply is the closest thing to it in this table.

What to avoid

• Any trouser sold on water repellency where the finish is not named. That is nine of the ten in the bottom tier.
• Assuming the premium outdoor brands have solved it. The North Face, Columbia and Fjällräven all have pairs on 20, and Patagonia's treated pairs reach only 45 on a brand statement.
• Reading a hiking label as meaning treated, or a chino as meaning untreated. Both Columbia pairs that pass are ordinary trousers, and a cotton and nylon North Face pair still carries a DWR finish.
• Reading a low grade as proof a garment contains PFAS, except on the Keb GTX where the record names PTFE directly.

The same finish runs through the rest of the kit. Our backpacks guide found thirteen of fifteen packs at 20, our rain jackets and ski jackets categories cover the shells, and the PFAS hazard page explains why durable water-repellent finishes attract scrutiny.

Our pick

Based on available materials and data, the Columbia Men's Stealth Spring Chino Pants at 65 out of 100 are the best-graded trouser here, and the honest caveat is that they are not hiking trousers in the technical sense. They will wet out in rain. For anyone who hikes in dry conditions or is happy to carry a shell, an untreated trouser is the only option in this table our data supports. If you need genuine weather protection, our data cannot point you to a pair we grade well. The three Patagonia pairs at 45 are the best-graded treated trousers here, on Patagonia's unverified statement, and the Fjällräven G-1000 range at least uses a wax Fjällräven names, beeswax and paraffin, which you can reapply yourself, rather than a finish nobody describes. These are estimates built from disclosed materials, not laboratory proof, and no product here is being called PFAS-free or safe by us.

FAQ

Is GORE-TEX PFAS?

GORE-TEX membrane has traditionally been expanded polytetrafluoroethylene, which is a fluoropolymer, and the one GORE-TEX garment in this table is recorded as exactly that. It is a bonded solid membrane rather than a surface spray, a distinction the industry considers important and one our model does not attempt to measure. GORE-TEX has been introducing non-fluorinated membranes in parts of its range, so the specific garment matters.

Why do two ordinary Columbia trousers beat all the technical ones?

Because they have no water-repellent finish. Our model responds to the treatment, and the trousers that skip it are the ones without the feature people buy technical trousers for. That is the trade this category forces.

Does the DWR wash out over time?

Durable water-repellent finishes are built to survive laundering, and they are commonly reapplied as they wear. Coating degradation with microfiber shedding appears among the recorded concerns here. Our data does not measure how much remains after washing.

Should I be worried about health effects from a lower-graded pair?

Any discussion of PFAS and health in our guides describes association, not proven causation, and grades measure estimated chemical concern based on materials and disclosure, not a medical risk assessment for any individual. If you want to reduce potential exposure across treated textiles, cross-reference products using our PFAS product finder.