Autoseal FreeFlow Stainless Steel Insulated Water Bottle vs Cold Tumbler: which is safer?

Ember Cold Tumbler is our pick: better on PFAS and on the overall hazard picture.

Coleman

Autoseal FreeFlow Stainless Steel Insulated Water Bottle

PFAS grade

A 95/100

Overall grade

B 83/100

Verdict

Buy

Hazard flags

⚑ 3

Material

Stainless steel interior and exterior, no coating disclosed

Confidence

85%

PossibleElastomer gasket and closure degradation

PossibleVolatile organic compound (VOC) off-gassing from cap or interior

PossibleBacterial biofilm growth in seal crevices

Why this gradeBuy

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

Why this gradeBuy

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