Mountainsmith · Waterproof Outdoor Gear Storage Bags
Mountainsmith Mayhem EVO 30 Backpack
Backpack with water-repellent coating; PFAS treatment undisclosed by brand.
Mountainsmith doesn't publicly disclose PFAS status for this backpack. water-repellent coating-treated outdoor gear typically uses fluorochemicals, though some modern alternatives exist.
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Material
nylon with water-repellent coating (water-repellent coating) finish
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
What Mountainsmith Mayhem EVO 30 Backpack is made of, ingredients and materials
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.
What’s concerning
Category baseline
The starting point for this type of product, before anything specific to this product is counted.
No PFAS disclosure
No public statement from the brand about PFAS in this product.
Waterproof / stain-resistant treatment
Water-repellent coating treatments have historically used PFAS.
PFAS
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.
Source, ATSDR ↗What’s reassuring
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 / VOCs
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.
Source, ATSDR ↗Heavy metals
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.
Source, FDA ↗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.
The full breakdown
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.
What we don’t know
- Basis
- Model estimate, 45% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- Mountainsmith has made none
Formulations change between production runs, so check the current label. How we grade.
Better-graded alternatives in Waterproof Outdoor Gear Storage Bags
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- UV degradation and additive leaching
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Marmot
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Patagonia
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- The brand calls it PFAS-free, which we have not verified
- PFAS
4 hazards checked on this product. See all of them.
More waterproof outdoor gear storage bags 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.