Sea to Summit · Waterproof Smartphone Cases
SEA TO SUMMIT TPU Guide Waterproof iPhone 5 Case Blue 358BL
TPU waterproof cases often use PFAS coatings; Sea to Summit discloses nothing.
This TPU case has waterproofing but Sea to Summit provides no PFAS disclosure. Waterproof phone cases frequently use fluorinated durable water repellents. Request material details from brand before purchase.
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 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
This case is TPU (thermoplastic polyurethane), a flexible plastic polymer that is inherently water-resistant but not fully waterproof. To achieve waterproof sealing, Sea to Summit applies a hydrophobic coating, most likely a Teflon-family coating or PFAS-based water-repellent coating (water-repellent coating). TPU itself is chemically inert under normal use, but the coating is the exposure concern. The material will yellow and degrade over 2-3 years of UV exposure and flexing, which can increase leaching potential as the polymer network breaks down.
The brand's record and disclosure
Sea to Summit is an outdoor gear brand with a stated sustainability focus, but they provide no public disclosure of PFAS use in waterproof cases or other products. No independent certifications (OEKO-TEX, bluesign, GOTS) are advertised for this item. The brand has not signed the AFIRM Group's PFAS commitment or published restricted substance lists specific to phone accessories. This silence is typical for outdoor gear makers, but it means you have no assurance the coating is PFAS-free.
How it compares in its category
Most waterproof phone cases (Pelican, OtterBox, Spigen) use TPU or rigid polycarbonate with Teflon-family coating coatings and face the same PFAS uncertainty. Cases labeled PFAS-free are rare and expensive. Sea to Summit's case is mid-market and functionally comparable to competitors; the hazard profile is typical rather than worse, but disclosure is equally absent across the category.
If you buy it
Do not expose the case to temperatures above 60°C (140°F), as TPU softens and coatings can off-gas. Replace it every 2-3 years once yellowing or cracking appears. Wash with cool water and mild soap only; avoid strong solvents or bleach, which accelerate coating breakdown. Store in a cool, dry place away from direct sunlight to slow degradation and reduce potential for PFAS leaching from a compromised coating.
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.”
Teflon-family coating/PFAS coating (waterproofing agent)
Waterproof TPU cases almost universally use PFAS-based water-repellent coating coatings. Sea to Summit discloses nothing, so assume presence unless stated otherwise. Risk is primarily dermal contact and potential ingestion if case degrades and releases coating particles.
TPU leaching (phthalate-free but plasticizer-dependent)
High-quality TPU contains non-phthalate plasticizers, but some formulations still use proprietary softening agents. Leaching risk increases if case is heated, cracked, or exposed to oils and solvents. Direct skin contact over hours is low-risk, but prolonged contact with phone (warm, in pockets) warrants periodic washing.
Coating degradation and microplastic shedding
TPU cases yellow and crack within 1-3 years under normal sun exposure and flexing. As the hydrophobic coating fails, it can shed microscopic particles into hand contact and onto skin. No branded studies exist for this specific model, but material degradation is documented across TPU phone case categories.
Thermal off-gassing (heat from phone battery)
Phone batteries can reach 40-50°C during heavy use or charging. TPU remains stable at this range, but borderline conditions (extended gaming, wireless charging in full sun) could accelerate volatile organic compound (VOC) release from coatings and plasticizers. Risk is minor but non-zero in high-heat scenarios.
Lead or cadmium in colorants
No recalls or public reports of heavy metals in Sea to Summit TPU cases. Reputable TPU molders typically use approved pigments, but third-party lab testing of this specific blue colorant has not been published. Risk is low for a major outdoor brand but not independently verified.
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.