Byron 2.0 Stainless Steel Travel Mug Snapseal vs Guardian Stainless Steel Tumbler: which is safer?

Contigo Byron 2.0 Stainless Steel Travel Mug Snapseal is the clear pick. Thermos Guardian Stainless Steel Tumbler carries a failing PFAS grade, and we never recommend buying a failing product.

Our pick

Contigo

Byron 2.0 Stainless Steel Travel Mug Snapseal

PFAS grade

A 95/100

Overall grade

B 83/100

Verdict

Buy

Hazard flags

⚑ 3

Material

Stainless steel, silicone gasket

Confidence

78%

PossibleSilicone gasket degradation

PossibleThermal stress cracking

PossibleLid seal failure and contamination

Why this gradeBuy

Thermos

Guardian Stainless Steel Tumbler

PFAS grade

F 55/100

Overall grade

F 43/100

Verdict

Skip

Hazard flags

⚑ 3

Material

Stainless steel interior, exterior coating unspecified

Confidence

72%

PossibleExterior coating composition and durability

PossibleSeal and gasket materials

PossibleThermal stress on adhesives

Why this grade

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 drinkware tumblers: see the full ranking