20-Ounce All Around Tumbler vs FreeSip Sway Stainless Steel: which is safer?
Owala FreeSip Sway Stainless Steel is our pick: better on PFAS and on the overall hazard picture.
Hydro Flask
20-Ounce All Around Tumbler
PFAS grade
Good 70/100
Overall grade
Good 59/100
Verdict
Skip
Hazard flags
⚑ 1
Material
stainless steel interior, vacuum-insulated
Confidence
78%
PossibleLid/gasket material degradation
Our pick
Owala
FreeSip Sway Stainless Steel
PFAS grade
Excellent 80/100
Overall grade
Good 68/100
Verdict
Buy
Hazard flags
⚑ 3
Material
Stainless steel body, no interior coating disclosed
Confidence
87%
PossibleSilicone and plastic lid/valve leachables
PossibleBacterial growth in valve mechanism
PossibleOff-gassing or odor transfer
Where these two actually differ
- We flag Lid/gasket material degradation on the Hydro Flask and not on the Owala.
- We flag Silicone and plastic lid/valve leachables, Bacterial growth in valve mechanism and Off-gassing or odor transfer on the Owala and not on the Hydro Flask.
- The Hydro Flask is stainless steel interior, vacuum-insulated where the Owala is Stainless steel body, no interior coating disclosed, 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