20/ 100
F
OverallF0/100
Mountainsmith Backpack Raincover

Mountainsmith · Portable Outdoor Gear Bags

Mountainsmith Backpack Raincover

F · High PFAS

Raincover material and coating composition not publicly disclosed.

Verdict: SkipPolyester raincover with undisclosed water-repellent coating poses possible flame retardant and formaldehyde risks; buy only if you accept unknown chemical inputs and plan proper maintenance.

Mountainsmith does not disclose PFAS status or coating chemistry for this raincover. Standard water-repellent coating treatments often contain PFAS; without transparency, higher concern applies.

Still want this one anyway? Check the price on Amazon. We’d swap it.

Material

Polyester with water-repellent coating water-repellent coating, unspecified

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.

Hurts the grade

Category baseline

clothing is a category where PFAS exposure is more common.

Hurts the grade

No PFAS disclosure

No public statement about PFAS in this product.

Hurts the grade

The full breakdown

What it's made of and why it matters

This raincover is polyester fabric with a water-repellent coating (water-repellent coating) coating, a finish that typically involves fluorinated compounds or, less commonly, silicone or wax-based alternatives. Mountainsmith does not publicly specify which water-repellent coating chemistry they use, leaving the exact chemical profile opaque. Polyester itself is stable under normal use, but the coating composition directly determines whether flame retardants, formaldehyde resins, or other treatment chemicals are present.

The brand's record and disclosure

Mountainsmith does not publish material safety data sheets, chemical transparency reports, or third-party certifications (such as bluesign or GOTS) for this raincover. No public recalls or documented chemical controversies specific to Mountainsmith raingear have been reported, but the brand's silence on water-repellent coating formulation is typical of mid-range outdoor brands that do not prioritize chemical disclosure. No evidence of a corporate PFAS reduction commitment exists in publicly available sources.

How it compares in its category

Raincover products are a niche subcategory; most comparable items use similar polyester-plus-water-repellent coating construction without public chemical specification. Brands like Patagonia and Arc'teryx increasingly disclose water-repellent coating alternatives (such as polyurethane or wax blends) and limit PFAS use, setting a higher transparency standard that Mountainsmith does not match. Budget raingear typically offers no such disclosure, making Mountainsmith's opacity unremarkable but not reassuring.

If you buy it

Wash the raincover in cool water with mild detergent before first use to reduce any loose finish residues. Avoid high heat (machine dry on low or air dry only); excessive heat can degrade coatings and potentially release volatile compounds. Replace if the water-repellent coating visibly degrades (water no longer beads), as deteriorating finish can expose underlying polyester. Store in a dry, well-ventilated space to prevent mildew and off-gassing.

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.”

Possible

Formaldehyde in polyester finishing resins

Polyester textiles often use formaldehyde-based resins for wrinkle resistance and shape retention. Mountainsmith does not specify whether their raincover uses these treatments; low-level emissions are possible but typically minimal in outdoor gear after initial use.

Reported

water-repellent coating (water-repellent coating) coating chemicals

water-repellent coating coatings historically rely on fluorinated compounds (related to but distinct from PFAS), or increasingly on silicone or wax alternatives. Without disclosure, the exact chemistry of this raincover's water-repellent coating is unknown; potential for skin or inhalation contact during extended use is low but not zero.

None known

Antimony in polyester

Polyester fiber itself may contain trace antimony from manufacturing catalysts. No specific reports link Mountainsmith polyester to antimony contamination, and residual levels in finished fabric are typically negligible.

Possible

Azo dyes or heavy metals in pigments

If the raincover is colored, synthetic azo dyes or heavy metal pigments could be present. No public testing or recalls on Mountainsmith raingear exist; compliance with standard textile safety regulations is presumed but not verified.

Possible

Coating degradation and particle shedding

As water-repellent coating coatings age and wear, fine particles or residues may shed into the environment or come into contact with skin. Proper care and timely replacement reduce this risk; the product manual does not specify a lifespan.

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.

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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.