Granite Gear · Waterproof Outdoor Gear Storage Bags
Granite Gear eVent Sil Drysack
Silent on PFAS; eVent membrane source unclear. Request details.
Granite Gear won't disclose PFAS use or testing results for this drysack. eVent is a Teflon-family coating membrane, meaning coating chemistry stays murky without contacting the brand directly.
Still want this one anyway? Check the price on Amazon. We’d swap it.
Material
Silicone-coated nylon with eVent membrane
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
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What Granite Gear eVent Sil Drysack is made of, ingredients and materials
This drysack uses silicone-coated nylon as its outer shell paired with an eVent microporous membrane for breathability while maintaining water resistance. The silicone coating replaces traditional polyurethane and provides flexibility and durability. eVent is a laminated membrane technology with a base polymer and thin polytetrafluoroethylene (Teflon-type coating) layer, which raises questions about Teflon-type coating content and PFAS chemistry that Granite Gear has not publicly clarified. The nylon substrate itself is stable and poses no known baseline hazard when properly treated.
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
EVent membranes use Teflon-type coating in laminate; if exposed to temperatures above 260°C (500°F), Teflon-type coating can release fumes. Normal drysack use does not reach this threshold, but exposure to fire, stovetops, or direct flame poses theoretical risk. Practical exposure is very low for a stored bag.
Source, ATSDR ↗Coating degradation and microfiber shedding
Silicone and Teflon-type coating-laminate coatings are durable but can flake or shed microparticles when abraded, wrinkled for extended periods, or aged. Shed particles may be breathed or ingested if bag contents contact food. Risk is minor under normal use but increases with wear and age.
Membrane delamination and loss of water resistance
EVent laminates can separate from base fabric under repeated flexing, washing, or age, particularly if exposed to solvents or heat. User reviews and forums document occasional early delamination in eVent gear, though not specific to Granite Gear model. Occurs as wear, not acute hazard, but reduces product lifespan and function.
What’s reassuring
Formaldehyde / VOCs
No formaldehyde-based resin finishes are typical on modern silicone-coated nylon drysacks. Granite Gear does not advertise such treatments. Standard nylon in waterproof bags is not a known source of formaldehyde release.
Source, ATSDR ↗Heavy metals
Nylon drysacks are dyed at the fiber stage; Granite Gear does not disclose dye chemistry. No recalls or test failures for heavy metals in this product or brand line are on record. Risk is consistent with standard outdoor nylon textiles.
Source, FDA ↗How is this PFAS grade calculated?
The brand's record and disclosure
Granite Gear is a Colorado-based outdoor gear manufacturer without publicly available PFAS policy, material transparency reports, or third-party certifications such as bluesign or GOTS. The brand does not disclose membrane supplier details, eVent coating composition, or chemical treatment processes on product pages or sustainability statements. No recalls or documented chemical safety incidents are on record for this model. Silence on PFAS and membrane sourcing is a gap in consumer information, not evidence of harm.
How it compares in its category
Silicone-coated nylon with eVent is mid-range in the drysack/waterproof bag segment. Many competitors use traditional polyurethane coatings (also PFAS-prone) or proprietary membrane systems with equally opaque sourcing. Some premium brands (e.g., Patagonia, Arc'teryx) publish PFAS commitments and membrane sourcing; budget brands rarely do. The eVent choice indicates breathability prioritization, which is functionally superior to non-breathable alternatives but does not resolve the PFAS disclosure gap.
If you buy it
Store in a cool, dry place away from direct UV and high heat, as silicone and Teflon-type coating-based coatings can degrade if exposed to sustained temperatures above 60-70 degrees Celsius (140-160 Fahrenheit). Do not machine wash or expose to solvents; rinse with cool water and air dry. Inspect the seams and membrane surface annually for cracking, peeling, or loss of water beading; replacement is advisable if coating integrity fails visibly. Request eVent membrane and silicone treatment details from Granite Gear before purchase if PFAS exposure is a personal concern.
What is not known about PFAS in this product?
- Basis
- Model estimate, 45% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- Granite Gear has made none
Formulations change between production runs, so check the current label. How we grade.
What are the PFAS-free alternatives to Granite Gear eVent Sil Drysack?
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3 hazards checked on this product, all on its full breakdown.
Find an alternative on Amazon
- Nylon, polyester, cotton blend; details unspecified
- Volatile organic compounds (VOCs) from polyester and nylon manufacturing
5 hazards checked on this product, all on its full breakdown.
Find an alternative on Amazon
- Recycled polyester with water-repellent coating (water-repellent coating) finish
- The brand calls it PFAS-free, which we have not verified
- PFAS
4 hazards checked on this product, all on its full breakdown.
Find an alternative on AmazonMore 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.