Osprey · Waterproof Outdoor Bags & Luggage
Osprey Sirrus 24 Hiking Backpack
Common water-repellent coating backpack, typical PFAS concern, no brand transparency
Osprey uses standard water-repellent coating coatings on nylon hiking packs, likely fluorinated but unconfirmed. No public PFAS disclosure or testing from brand.
The safe swap
Garmin
Garmin Carry Case
85/100 safety
Same rubric that flunked this product. The swap earned its B.
Still want this one anyway? Check the price on Amazon. We’d swap it.
Material
Nylon fabric 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
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
The Sirrus 24 uses nylon fabric with a water-repellent coating (water-repellent coating) finish, which typically contains fluorinated compounds (PFAS) to repel water without adding bulk. Nylon itself is a stable synthetic polymer and does not leach hazardous chemicals under normal conditions. The water-repellent coating sits on the surface and does not contact food or skin directly during typical backpack use, limiting direct exposure pathways compared to cookware or food-contact items.
The brand's record and disclosure
Osprey has not published a formal PFAS phase-out commitment or transparency report on water-repellent coating chemistry in its product lines. The company maintains general sustainability messaging but does not disclose whether it uses PFAS-free alternatives like wax-based or silicone water-repellent coating on this model. This silence is common among outdoor brands but reflects a lack of third-party verification or proactive chemical management that more transparent competitors have adopted.
How it compares in its category
Most hiking backpacks in this capacity and price range (USD 100-150) use fluorinated water-repellent coating finishes; PFAS-free alternatives exist but are rare and often more expensive or perform less effectively in wet conditions. Osprey's Sirrus 24 is competitive but not differentiated on chemical safety. Brands like Patagonia have committed to phasing out legacy PFAS, making them a safer choice if water-repellent coating chemistry is a priority for you.
If you buy it
Store the pack in a cool, dry place away from heat sources; prolonged sun exposure or machine washing at high temperatures may degrade the water-repellent coating finish and theoretically increase surface wear. Wash by hand with mild soap and water if needed; avoid harsh detergents that strip water-repellent coating coatings. The nylon itself is durable; replace the pack if straps fray or seams separate, as this does not present a chemical hazard but compromises function. water-repellent coating will wear down over 2-5 years of heavy use and can be reapplied with commercial 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 finish
This pack almost certainly contains fluorinated water-repellent coating compounds given the price point and Osprey's lack of public commitment to PFAS-free alternatives. water-repellent coating does not leach into skin or food during normal backpack use, but microfiber shedding during washing or wear may mobilize trace PFAS, especially in aquatic environments.
Azo dyes in nylon fabric
No recalls or reports link Osprey Sirrus packs to restricted azo dyes. Nylon dyeing does use azo compounds in some cases, but exposure during normal wearing is negligible; risk is primarily occupational for textile workers.
Formaldehyde resins in fabric finishing
Nylon textiles may be treated with formaldehyde-based resins for shape retention and crease resistance. Off-gassing from new fabric is usually minimal and dissipates within days to weeks of airing. No published data exists for this specific Osprey model.
Antimony in synthetic fibers
Antimony is used as a polyester catalyst but nylon does not require it; the Sirrus 24 uses nylon, not polyester as the primary shell, so antimony risk is not applicable.
Microfiber shedding during washing
Nylon backpacks shed microfibers during machine or vigorous hand washing. While the fibers themselves are not toxic, they can carry surface contaminants including water-repellent coating-bound PFAS into waterways. Hand washing with minimal agitation reduces shedding.
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 Waterproof Outdoor Bags & Luggage
Garmin
Carry Case
Neoprene or polyester with nylon hardware
Lower concern protective case, no known PFAS risk signals.
⚠Brand says nothing about PFAS
Keen
Hybrid Transport Backpack Tan Recycled Rice Paper Plastic Daypack
Recycled rice paper, plastic composite, no evident water-resistant coating
Lower concern. Plain materials, no apparent water-repellent coating treatment.
⚠Brand says nothing about PFAS
More waterproof outdoor bags & luggage 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.