PFAS score
REI Co-op · Waterproof Hiking Socks
REI Co-op Merino Wool Lightweight Hiking Socks (2 Pairs)
Lower PFAS concern, plain merino wool, though no PFAS disclosure standard applies to REI Co-op.
Merino wool is an inherently lower-PFAS-risk fiber; REI Co-op does not disclose water-repellent coating treatments on this lightweight sock.
Still want this one anyway? Check the price on Amazon. We’d swap it.
Material
Merino wool blend (no water-resistant treatment disclosed)
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
Why this grade
Category baseline
clothing is a category where PFAS exposure is more common.
No PFAS disclosure
No public statement about PFAS in this product.
Safe base material
Made from a material with no inherent PFAS use (ceramic, mineral, or natural fiber).
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 78% confidence. It is not a lab result.
No independent PFAS lab test is on record for this exact product. A lab test could move the score in either direction.
The brand has not made a specific, verifiable PFAS-free statement, so part of this score reflects that missing disclosure rather than a confirmed material.
Formulations and coatings change between production runs. Always check the current label before buying.
More waterproof hiking socks grades
How we score: every product runs through the same public 0–100 rubric based on materials, coatings, brand disclosure, lab findings, and recalls. See the full methodology → Spotted a mistake? Report an error.