Osprey · Waterproof Outdoor Gear Storage Bags
Osprey Ultralight Dry Sack
Dry sacks use water-repellent coating coatings; brand does not disclose PFAS status.
Osprey's ultralight dry sacks likely use water-repellent coating treatment, a common water-repellent coating application. No public PFAS disclosure or third-party testing available from the brand.
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Material
Nylon fabric with water-repellent coating
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
other 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
Osprey Ultralight Dry Sack is nylon fabric (typically nylon 6 or 6.6) with a water-repellent coating (water-repellent coating) coating applied to the exterior. water-repellent coating coatings are the primary chemical concern in this product class, as they historically contained Teflon-type coating or fluorinated compounds (PFAS). The nylon itself is chemically stable and does not leach into water or food under normal storage use. The sack is designed for dry storage of gear, not direct food contact, which limits exposure routes.
The brand's record and disclosure
Osprey does not publicly disclose the specific water-repellent coating chemistry used on this product or commit to PFAS-free coatings. The brand has not published statements on fluorochemical phase-out or testing results for their technical textiles. This silence is common in the outdoor gear industry but leaves uncertainty about whether fluorinated or non-fluorinated water-repellent coating is in use. No recalls or safety controversies specific to Osprey dry sacks are on record.
How it compares in its category
Dry sacks as a category present lower chemical exposure risk than food-contact or skin-contact items because contents are not consumed and skin contact is incidental. Osprey is a reputable outdoor brand with quality control standards, but many competitors (including some small manufacturers) now market PFAS-free or polyether-based water-repellent coating options, which Osprey does not advertise. Most ultralight dry sacks use similar nylon-plus-coating construction, so material risk is category-wide rather than brand-specific.
If you buy it
Store only non-food, non-skin-contact items (gear, clothes, electronics) to minimize any potential leachate contact. Avoid washing with hot water or mechanical agitation if possible; gentle hand rinse with cool water preserves the water-repellent coating longer. Replace the sack if the exterior coating visibly degrades, peels, or loses water repellency, as this signals the water-repellent coating is breaking down and may release residual coating material. Do not use for long-term food storage; these are designed for temporary gear protection during outdoor trips.
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.”
water-repellent coating durability and potential degradation byproducts
The water-repellent coating degrades over time and with washing, especially with chlorinated water or detergents. As coating degrades, microscopic particles or residual coating chemicals may shed; specific composition unknown due to brand non-disclosure, but risk is manageable through limited washing and replacement.
Nylon fiber shedding and microfiber migration
Nylon dry sacks do not shed microfibers into stored contents under normal conditions because contents are not abraded against the fabric. Risk would only arise if the sack is machine-washed vigorously or stored compressed in wet conditions for extended periods.
Heavy metals or dyes in nylon or coating
No testing data or recalls link Osprey dry sacks to heavy metal contamination. Nylon production can involve trace metals in catalysts, but these remain locked in the polymer matrix and do not leach in dry storage use.
Volatile organic compounds (VOCs) from coating or adhesives
New dry sacks may off-gas slight solvent odors from water-repellent coating application or seam sealing adhesives. This is typical of outdoor gear and dissipates within days to weeks of airing out; not a safety issue for gear storage, only a sensory nuisance.
PFAS in water-repellent coating (graded separately above)
Industry-wide issue: most nylon water-repellent coating coatings historically used Teflon-type coating or C6-C8 fluorocarbons (PFAS). Osprey does not disclose whether this product uses legacy fluorinated or newer non-fluorinated chemistry. Given the brand's silence, fluorinated water-repellent coating cannot be ruled out.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 42% 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 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.