S'well · Insulated Travel Mugs
S'well Vacuum Insulated Travel Mug with Handle
Lower concern, but S'well provides no PFAS disclosure.
S'well travel mugs use stainless steel insulation, a lower-risk material. The brand does not publicly disclose PFAS use or testing; handle and cap plastics are unspecified.
Shop S'well on Amazon →Material
Stainless steel body, plastic handle and cap
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
Why this grade
Safe base material
Made from a material with no inherent PFAS use (ceramic, mineral, or natural fiber).
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
S'well travel mugs use 18/8 stainless steel for the main body, which is highly resistant to corrosion and does not leach metals into beverages under normal use. The plastic handle and cap are typically polypropylene or similar commodity polymers, which are food-contact approved but can release small amounts of monomers or additives if exposed to sustained heat well above normal hot-beverage temperatures (above 70°C for extended periods). The interior vacuum seal eliminates direct plastic-to-liquid contact for the beverage itself, limiting exposure routes.
The brand's record and disclosure
S'well does not publicly disclose PFAS test results, manufacturing certifications (BPA-free, heavy-metal tested), or third-party safety audits on their website or product labels. The brand has no documented product recalls related to chemical leaching or safety hazards on the FDA or CPSC databases. They market products as suitable for hot and cold beverages but provide no technical guidance on temperature limits or polymer composition details, which limits independent verification of safety claims.
How it compares in its category
Stainless steel vacuum travel mugs are among the safest beverage vessels because the material itself does not leach; S'well is mid-to-premium priced ($30-50 range) and competes on design rather than safety differentiation. Compared to ceramic-lined or non-insulated plastic bottles, this design eliminates ceramic glaze unknowns and plastic-beverage contact, making it objectively lower-risk. However, competing brands like Hydro Flask and Contigo similarly lack public PFAS or toxicology disclosure, so S'well is not exceptional in transparency.
If you buy it
Hand-wash the lid and handle rather than running through a dishwasher to minimize plastic thermal stress and preserve coatings. Do not fill with water above 80°C or leave hot liquids in the mug overnight, as prolonged heat exposure to the cap seal is the highest-risk scenario for plastic additive migration. Replace the lid if it shows visible cracks, discoloration, or odor, as these indicate polymer breakdown. Store dry and away from direct sunlight to prevent UV degradation of the plastic handle over years of use.
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.”
Plastic cap/handle thermal migration
Polypropylene handles and caps may release trace amounts of oligomers or processing residues if exposed to sustained temperatures above 70-80°C. Risk is low under normal use (filling with fresh hot beverages and drinking within minutes) but increases if boiling water is poured directly into an unsecured cap or if the mug is left filled with hot liquid for hours.
Undisclosed polymer type and additives in handle/cap
S'well does not publicly specify whether the plastic handle is virgin or recycled polypropylene, or what UV stabilizers, release agents, or colorants are used. Without material transparency, potential presence of legacy additives (e.g., heavy metals in pigments or unknown phthalate alternatives) cannot be ruled out, though food-contact regulations make this unlikely.
Stainless steel body integrity and welding seams
No recalls or documented issues with corrosion, leaching, or defects in S'well's 18/8 stainless steel bodies. This grade is resistant to rust and metal ion leaching under all normal beverage use conditions, including acidic drinks like citrus juice or coffee.
Vacuum seal degradation and mold growth
If the cap gasket or seal is damaged, moisture can enter the vacuum cavity, leading to condensation and potential microbial growth (mold, bacteria) in the insulation layer. This is a maintenance issue rather than a manufacturing hazard but can occur if the mug is not hand-dried after washing or if the seal is compromised by repeated impact or drops.
No third-party safety or PFAS testing disclosed
S'well has made no public commitment to PFAS testing, BPA-free certification, or heavy metal screening for either the stainless steel or plastic components. While stainless steel is inherently low-risk, the plastic handle's undisclosed manufacturing provenance creates an information gap, though no specific hazard has been reported in product testing or complaints.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 72% 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.
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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.