S'WELL Water Bottle
Lower concern, stainless steel bottles rarely require PFAS, but S'well does not publicly disclose material treatments or PFAS policy.
Double-wall stainless steel typically doesn't require Teflon-family coating coatings or water-repellent treatments. S'well hasn't disclosed PFAS-related statements or testing.
The better-graded swap
Grayl
Grayl GeoPress Ti Purifier
95/100 safety
Same rubric that flunked this product. The swap earned Excellent.
Still want this one anyway? Check the price on Amazon. We’d swap it.
Material
Double-wall stainless steel (primary container material)
Lab data
No public lab test
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What S'WELL Water Bottle is made of, ingredients and materials
S'well bottles use food-grade stainless steel (typically 18/8 or 304 grade) as the primary container, which is chemically inert and does not leach metals under normal use. The double-wall design contains an air gap for insulation rather than foam or polymeric fillers, eliminating off-gassing concerns common in insulated plastics. The lid and cap assembly may contain silicone or plastic gaskets, which represent the only potential exposure point for polymer-derived contaminants, though these are typically food-safe grade silicone.
What’s concerning
No PFAS disclosure
No public statement from the brand about PFAS in this product.
Silicone/plastic gasket degradation
Lid gaskets and cap seals are typically food-grade silicone but S'well does not disclose specific composition. Long-term exposure to hot beverages or dishwasher heat may cause minor breakdown; no leaching of BPA or phthalates is expected from silicone, but gasket replacement over product lifetime may be needed.
Bacterial growth in lid mechanism
Double-wall stainless steel interior is resistant to biofilm, but the threaded cap, silicone seal crevices, and gasket channels can harbor bacteria if not regularly cleaned. This is a hygiene issue rather than a toxic exposure risk but is relevant to reusable bottle maintenance.
What’s reassuring
Base material not linked to PFAS
The main material recorded for this product is not one associated with PFAS.
Stainless steel corrosion and metal leaching
Food-grade 304/18-8 stainless steel does not leach chromium or nickel under normal room-temperature use with neutral pH water. Risk is negligible unless bottle is damaged, exposed to highly acidic beverages for extended periods, or exposed to saltwater environments.
Heavy metals
No recalls or contamination events have been documented for S'well bottles. However, the brand does not publish third-party testing or certifications of heavy metal content in finished bottles, leaving this unverified.
Source, FDA ↗Off-gassing or volatile organic compounds
Stainless steel and silicone do not off-gas VOCs under normal conditions. The absence of foam insulation, adhesives, or polymer coatings means VOC exposure is not a recognized hazard for this product type.
How is this PFAS grade calculated?
The brand's record and disclosure
S'well does not publish detailed material sourcing, testing protocols, or PFAS disclaimers on their website or product literature. The brand has not pursued third-party certifications (NSF, FDA compliance statements, or heavy metal testing disclosure) that would provide independent verification of safety claims. No significant product recalls or contamination incidents have been reported in public databases. This silence on material transparency is a notable gap given competitor brands' increasing openness about manufacturing standards.
How it compares in its category
S'well bottles are positioned as premium reusable water bottles, not water filters; the category context may be mislabeled, as they hold liquid but do not filter it. Compared to typical stainless steel alternatives (Hydro Flask, Klean Kanteen), S'well offers similar material safety but with less public disclosure of testing or certifications. Against plastic bottles (Nalgene, competitor BPA-free models), stainless steel inherently avoids BPA, phthalate, and microplastic leaching risks. S'well's price point and marketing suggest durability, but material lifecycle and recycling information are not prominently disclosed.
If you buy it
Hand-wash the bottle and lid with warm soapy water rather than dishwasher to preserve the exterior finish and avoid potential degradation of lid seals over time. Do not fill with boiling water immediately after closing, as thermal stress may affect seal integrity. Inspect gaskets and interior surfaces annually for discoloration, pitting, or odors that could indicate corrosion or biofilm accumulation; replace the cap assembly if seals degrade. The stainless steel exterior will not degrade from normal use, but avoid prolonged contact with acidic beverages that may cause minor surface discoloration over years of use.
What is not known about PFAS in this product?
- Basis
- Model estimate, 72% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- S'well has made a specific claim
Formulations change between production runs, so check the current label. How we grade.
What are the PFAS-free alternatives to S'WELL Water Bottle?
- glass bottles, sodium dichloroisocyanurate treatment chemical
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- Chemical overdose or misuse
5 hazards checked on this product, all on its full breakdown.
- Stainless steel housing and spigot
- We found no PFAS statement from the brand
- Bacterial growth and biofilm if filters not replaced
5 hazards checked on this product, all on its full breakdown.
- Borosilicate glass pitcher, replaceable activated-carbon filter cartridge
- Bacterial growth in filter cartridge if unmaintained
5 hazards checked on this product, all on its full breakdown.
More water filters 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.