S'ip by S'well Takeaway Mug vs Stainless Steel King Travel Mug: which is safer?

THERMOS Stainless Steel King Travel Mug is our pick: better on PFAS and on the overall hazard picture.

S'ip by S'well Takeaway Mug

S'well

S'ip by S'well Takeaway Mug

PFAS grade

Excellent 85/100

Overall grade

Good 73/100

Verdict

Buy

Hazard flags

⚑ 3

Material

Stainless steel exterior, insulated

Confidence

72%

PossibleBPA/BPS in interior lining or gaskets

PossibleBacterial growth in lid seals

PossibleThermal shock or seal failure from temperature cycling

Our pick

THERMOS Stainless Steel King Travel Mug

Thermos

Stainless Steel King Travel Mug

PFAS grade

Excellent 95/100

Overall grade

Excellent 83/100

Verdict

Buy

Hazard flags

⚑ 3

Material

Stainless steel interior and exterior, plastic lid

Confidence

82%

PossiblePlastic lid polymer degradation

PossibleGasket/seal material composition

PossibleThermal shock stress on seals

Where these two actually differ

  • We flag BPA/BPS in interior lining or gaskets, Bacterial growth in lid seals and Thermal shock or seal failure from temperature cycling on the S'well and not on the Thermos.
  • We flag Plastic lid polymer degradation, Gasket/seal material composition and Thermal shock stress on seals on the Thermos and not on the S'well.
  • The S'well is Stainless steel exterior, insulated where the Thermos is Stainless steel interior and exterior, plastic lid, which is most of the difference in these two grades.

Both products run through the same public rubric: materials, coatings, brand disclosure, lab findings, and recalls, plus a beyond-PFAS hazard analysis. Grades are model-based estimates, not lab tests. How grades work →

More insulated travel mugs: see the full ranking