Mountainsmith · Portable Outdoor Gear Bags
Mountainsmith Mayhem EVO 30 Backpack
Backpack with water-repellent coating; PFAS treatment undisclosed by brand.
Mountainsmith does not publicly disclose PFAS status for this backpack. water-repellent coating-treated outdoor gear typically uses fluorochemicals, though some modern alternatives exist. Direct inquiry with brand recommended.
Still want this one anyway? Check the price on Amazon. We’d swap it.
Material
nylon with water-repellent coating (water-repellent coating) finish
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
Why this grade
Waterproof / stain-resistant treatment
water-repellent coating treatments have historically used PFAS.
Category baseline
clothing is a category where PFAS exposure is more common.
No PFAS disclosure
No public statement about PFAS in this product.
The full breakdown
What it's made of and why it matters
The Mayhem EVO 30 is constructed from nylon fabric with a water-repellent coating (water-repellent coating) finish. water-repellent coating coatings historically relied on Teflon-type coating-based or fluorinated compounds (PFAS) to repel water; the brand has not disclosed which formulation is used here. Nylon itself is a synthetic polyamide that is chemically stable under normal use and does not leach significant hazardous compounds when worn or stored at room temperature.
The brand's record and disclosure
Mountainsmith has not published detailed materials disclosures or PFAS avoidance commitments as of available public records. The company does not advertise use of fluorine-free water-repellent coating alternatives or third-party certifications (such as OEKO-TEX or bluesign) that would rule out legacy PFAS treatments. This silence on a routine manufacturing choice is typical of mid-market outdoor brands but represents a missed opportunity for transparency.
How it compares in its category
Among 30-liter technical backpacks, the Mayhem EVO 30 is mid-range in price and mainstream in materials. Competitors like Osprey and Arc'teryx increasingly disclose fluorine-free or low-PFAS water-repellent coating options; REI Co-op branded packs often highlight cleaner coatings. Mountainsmith's silence puts it behind leaders in disclosure but does not indicate unusual hazard levels for the category.
If you buy it
Hand wash or rinse the pack with cool water rather than machine washing, which can accelerate water-repellent coating degradation and potential microfiber release. Avoid high heat and direct sunlight exposure, which degrade nylon over time. Store in a dry place to prevent mold growth in the fabric. If the water-repellent finish noticeably fails (water pools on the surface rather than beading), consider re-treatment with a PFAS-free water-repellent coating product rather than recoating with legacy fluorinated products.
Beyond PFAS: other things we checked
Established hazard classes for this product type, assessed from public information. These never change the PFAS grade; a Likely flag caps the Verdict at “Buy with care.”
PFAS in water-repellent coating (fluorinated water repellent)
The water-repellent coating finish on this pack is undisclosed; if fluorinated (Teflon-type coating or legacy C8/C6 PFAS), minimal dermal exposure occurs during wear, but manufacturing wastewater and eventual disposal pose environmental release risk. Brand silence prevents assessment of whether fluorine-free alternatives were chosen.
Nylon microfiber shedding
Nylon backpacks shed microscopic fibers during abrasion and washing. For a pack worn on the back, dermal contact is minimal; environmental release during laundering is the primary concern but is not specific to this brand and occurs across the category.
Formaldehyde in fabric finishes or dyes
No recalls or published reports of excess formaldehyde in Mountainsmith nylon packs. Standard commercial nylon dyeing and finishing processes may include trace formaldehyde releasers, but levels in outdoor technical fabrics are typically low and regulated by consumer product safety standards.
Azo dyes and heavy metal colorants
No specific hazard reported for this product. Nylon technical packs use modern synthetic dyes; restricted azo dyes and heavy metals are uncommon in mainstream outdoor gear, though brand does not publish dye chemistry or heavy metal testing.
Adhesive and seam-sealing compounds
Seam sealing and fabric adhesives in the pack may contain volatile organic compounds (VOCs) or polyurethane-based formulations. Off-gassing typically diminishes within days to weeks; no specific health incidents are on record for this brand.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 45% 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.
Safer alternatives in Portable Outdoor Gear Bags
REI Co-op
Trailgate Gear Bin Green 140 L
Polypropylene storage bin, no water-resistant coating mentioned
Lower PFAS concern for bare plastic storage container.
⚠Risky category by default
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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.