REI · Waterproof Outdoor Gear Storage
Gregory Alpaca 45 Gear Box
Waterproof backpack likely treated; REI discloses nothing about PFAS.
Gregory alpaca packs use durable, waterproofed nylon typical of hiking gear. No public PFAS disclosure from Gregory or REI; waterproof treatments often contain PFAS but specifics unknown for this model.
The safe swap
REI
Humangear Stax
100/100 safety
Same rubric that flunked this product. The swap earned its A.
Still want this one anyway? Check the price on Amazon. We’d swap it.
Material
Ballistic nylon exterior with waterproof backing
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 Gregory Alpaca 45 uses ballistic nylon (high-denier woven polyester) for its exterior, chosen for abrasion resistance and durability in outdoor use. The waterproof backing is the safety concern: this backing is almost certainly a polymer coating (likely polyurethane or similar) that may be treated with fluorinated water repellents to achieve durability. Ballistic nylon itself is inert polyester; the risk lies in how the waterproofing layer degrades over time and whether it was treated with PFAS compounds.
The brand's record and disclosure
REI Co-op does not publicly disclose PFAS use or avoidance in its gear line, including Gregory-branded products sold under their label. REI has not pursued PFAS-free certifications or transparency initiatives comparable to some competitors (e.g., Patagonia, which began phasing PFAS in 2018). No recalls or safety controversies are documented for this specific model. REI's silence on PFAS treatment of technical fabrics is standard industry practice but represents a gap in consumer transparency.
How it compares in its category
Most durable outdoor backpacks in this capacity use ballistic nylon or similar high-denier synthetics with waterproof coatings; PFAS-free alternatives exist (e.g., some waxed canvas or polyester with polyurethane-only backing) but are less common in performance-oriented packs at this price point. The Gregory Alpaca 45 is a mid-range pack; ultralight or luxury alternatives may offer better material transparency. REI's house-brand transparency lags smaller outdoor brands that explicitly certify PFAS-free construction.
If you buy it
Inspect the waterproof backing annually for peeling, cracking, or delamination; these signs indicate coating breakdown and potential exposure. Clean the pack with mild soap and water; avoid heat sources and machine washing, which can degrade the backing and may accelerate any leachable compound release. Store dry in a cool place; prolonged heat or humidity can accelerate polymer degradation. If the backing fails significantly, the pack is past safe repair; replacement is advisable because re-sealing with consumer products may introduce additional unknowns.
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.”
Waterproof coating degradation and potential leachables
Polyurethane or similar polymer backings degrade with UV exposure, heat, and friction over 3-5 years of use. If the backing was treated with PFAS (unknown for this product), degradation could theoretically increase dermal or indirect food contact exposure, though actual risk depends on use pattern and whether the pack contacts food or skin directly.
Polyester fiber shedding (microfiber release)
Ballistic nylon is a woven fabric and does not shed microfibers as readily as fleece or knit synthetics. No established hazard documented for ballistic nylon backpacks; risk is negligible compared to textiles washed frequently.
Dyes and finishes in ballistic nylon
No azo dyes, formaldehyde resins, or heavy metal contamination is documented in ballistic nylon production for outdoor gear. Standard industrial dyes used in technical nylon are not reportable hazards for external-contact equipment.
Metal hardware (zippers, buckles) corrosion and leaching
Gregory uses high-quality zinc-alloy or stainless hardware on this model; no lead, cadmium, or nickel leaching is documented or expected. Standard for outdoor gear in this price range.
Glues and adhesives in seams
Ballistic nylon backpacks use polyurethane or contact adhesives at seams and patch applications. These are not known to offgas significantly in outdoor equipment; risk is minimal but increases if the pack is stored in extreme heat or sealed in a warm vehicle for extended periods.
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 Gear Storage
REI
Humangear Stax
polypropylene plastic
Lower concern. Polypropylene stacking containers lack PFAS triggers.
✓Naturally PFAS-free material
REI
DECKED Sixer 16 D-co Case
Plastic case (DECKED cooler construction)
Rigid plastic case, likely lower concern but no PFAS disclosure available.
⚠Brand says nothing about PFAS
Coleman
Chiller Cooler
Plastic (polypropylene) cooler body, foam insulation
Lower concern cooler. No known PFAS-treated materials typical.
⚠Brand says nothing about PFAS
More waterproof outdoor gear storage 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.