CUPKIN Stainless Steel Insulated Tumbler with Lid and Straw vs Cold Tumbler: which is safer?
Ember Cold Tumbler is our pick: better on PFAS and on the overall hazard picture.
Cuppy
CUPKIN Stainless Steel Insulated Tumbler with Lid and Straw
PFAS grade
A 95/100
Overall grade
B 87/100
Verdict
Buy
Hazard flags
⚑ 2
Material
stainless steel body, standard plastic lid and straw
Confidence
72%
PossiblePlastic lid and straw degradation under heat
PossibleLid seal material and mold/bacterial growth if not dried
Our pick
Ember
Cold Tumbler
PFAS grade
A 100/100
Overall grade
A 92/100
Verdict
Buy
Hazard flags
⚑ 2
Material
stainless steel with silicone seal
Confidence
72%
PossibleSilicone seal degradation and microbial growth
PossibleCoatings or adhesives on printed logos
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 drinkware: see the full ranking