Sea to Summit · Waterproof Smartphone Cases
Sea to Summit TPU Guide Waterproof Case
TPU waterproof case, treatment composition undisclosed. Moderate uncertainty.
Sea to Summit's TPU case uses waterproofing treatment but brand does not disclose PFAS content or water-repellent coating chemistry. Standard TPU is lower concern than Teflon-family coating coatings, but waterproof treatment composition remains unknown.
The safe swap
Mophie
Mophie Juice Pack Battery Case for iPhone 15
85/100 safety
Still want this one anyway? Check the price on Amazon. We’d swap it.
Material
TPU (thermoplastic polyurethane) with waterproof treatment
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
TPU (thermoplastic polyurethane) is a synthetic polymer that is inherently flexible, durable, and water-resistant without coating. Sea to Summit applies an additional waterproof treatment to this case, but the company has not publicly disclosed the chemical composition of that treatment. TPU itself does not leach BPA or phthalates under normal storage conditions, making it safer than many soft plastics. The undisclosed treatment is the primary concern, as waterproof coatings on textiles and plastics often historically used PFAS-based durable water repellents.
The brand's record and disclosure
Sea to Summit is an outdoor gear company with no publicly available PFAS policy or waterproof-treatment ingredient disclosures for their cases. The brand does not appear on major lists of companies with established PFAS phase-out commitments (such as ZDHC Gateway or manufacturer pledges). No product-specific recalls or chemical contamination reports for this case are on record. This silence on formulation is a red flag in a category where waterproofing chemicals are a known hazard vector.
How it compares in its category
Waterproof cases and drybags are typically made from PVC, nylon with polyurethane coating, or TPU. TPU is generally considered a lower-hazard substrate than rigid PVC (which can leach plasticizers). However, competitors like Ortlieb and some Decathlon drybags have begun disclosing PFAS-free or PFAS-reduced treatments; Sea to Summit has not matched this transparency. The lack of certification (e.g., Bluesign, GOTS, or PFOA/PFOS-free claims) puts it in the middle-uncertainty tier for this product type.
If you buy it
Store the case away from direct heat and sunlight, as TPU can soften above 60C (140F) and any coating may degrade if heated. Do not place it in high-temperature environments or near heaters. Hand-wash with cool water and mild soap if needed; avoid harsh solvents or bleach, which can degrade the waterproof layer. Inspect regularly for coating wear or cracking; if the waterproof layer begins to flake or peel, consider replacement to avoid exposure to the underlying treatment residue.
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.”
Undisclosed waterproof coating composition (possible PFAS)
Sea to Summit has not disclosed whether the waterproof treatment on this TPU case contains PFAS-based durable water repellents (DWRs) or alternative chemistries. Historical industry practice suggests legacy DWRs often contained PFOA/PFOS or related compounds; current alternatives vary widely.
TPU thermal degradation and fume release
If heated above its glass-transition temperature (typically 60-80C depending on formulation), TPU can release volatile organic compounds. While not classified as acute hazard like Teflon-type coating cookware fumes, prolonged heating in enclosed spaces should be avoided.
Coating degradation and secondary exposure
Waterproof coatings on flexible materials can crack, peel, or flake with age and use. Degraded coating may shed microparticles or expose underlying treatment chemicals; regular inspection is recommended.
Plasticizer leaching into stored contents
TPU itself contains fewer problematic plasticizers than older PVC or vinyl alternatives. No established reports of leaching from TPU waterproof cases into food, water, or skin contact items under normal storage.
Fragmentation and microplastic shedding
Like all synthetic polymers, TPU can degrade over time with UV exposure and mechanical stress, generating microplastic particles. Extended outdoor use without protective storage may accelerate this process.
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 Smartphone Cases
Mophie
Juice Pack Battery Case for iPhone 15
Lithium-ion battery, plastic housing, metal contacts
No known PFAS use; battery cases rarely require fluorinated coatings.
⚠Brand says nothing about PFAS
Mophie
Juice Pack Battery Case for iPhone 15 Pro
Lithium-ion battery, plastic housing, rubber grips
Lower concern. Battery cases lack typical PFAS-prone coatings; no public disclosure available.
⚠Brand says nothing about PFAS
Pelican
Shield Phone Case for Samsung Galaxy S24 Plus
Polycarbonate shell, rubber grip
Lower concern; typical phone case with no known PFAS applications.
⚠Brand says nothing about PFAS
More waterproof smartphone cases 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.