FreeSip Stainless Steel Tumbler vs Stainless Steel King Travel Mug: which is safer?
Owala FreeSip Stainless Steel Tumbler is our pick: better on PFAS and on the overall hazard picture.
Our pick
Owala
FreeSip Stainless Steel Tumbler
PFAS grade
Excellent 80/100
Overall grade
Good 72/100
Verdict
Buy
Hazard flags
⚑ 2
Material
stainless steel tumbler, no stated coating
Confidence
82%
PossibleSilicone gasket degradation and ingestion
PossibleMold or bacterial growth in lid seals
Thermos
Stainless Steel King Travel Mug
PFAS grade
Excellent 80/100
Overall grade
Good 68/100
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 Silicone gasket degradation and ingestion and Mold or bacterial growth in lid seals on the Owala 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 Owala.
- The Owala is stainless steel tumbler, no stated coating where the Thermos is Stainless steel interior and exterior, plastic lid, which is most of the difference in these two grades.
- These two are level, close enough that price and fit should decide it rather than our grade.
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