12 oz Outdoor 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
12 oz Outdoor Tumbler
PFAS grade
Good 70/100
Overall grade
Good 59/100
Verdict
Skip
Hazard flags
⚑ 1
Material
Stainless steel wall construction with foam insulation
Confidence
72%
PossibleCoating degradation and foam exposure
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 Coating degradation and foam exposure 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 wall construction with foam insulation 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