FreeSip Stainless Steel Tumbler vs Rambler 24 oz Mug with Ceramic Lining: which is safer?
Rambler 24 oz Mug with Ceramic Lining is our pick, better on PFAS and on the overall hazard picture.
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
Our pick
Yeti
Rambler 24 oz Mug with Ceramic Lining
PFAS grade
Excellent 85/100
Overall grade
Good 73/100
Verdict
Buy
Hazard flags
⚑ 3
Material
stainless steel exterior, ceramic lining interior
Confidence
72%
PossibleCeramic coating degradation over time
PossibleBacterial growth in crevices or damaged coating
PossibleThermal shock or fracture
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 Yeti.
- We flag Ceramic coating degradation over time, Bacterial growth in crevices or damaged coating and Thermal shock or fracture on the Yeti and not on the Owala.
- The Owala is stainless steel tumbler, no stated coating where the Yeti is stainless steel exterior, ceramic lining interior, which is most of the difference in these two grades.
- These two are 5 points apart, close enough that price and fit should decide it rather than our grade.
Both products run through the same public rubric, which covers 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