Double Wall Vacuum Insulated Stainless Steel Food Canister Container with Leak Proof Lid vs MB Square Bento Box: which is safer?
Klean Kanteen Double Wall Vacuum Insulated Stainless Steel Food Canister Container with Leak Proof Lid is our pick: better on PFAS and on the overall hazard picture.
Our pick
Klean Kanteen
Double Wall Vacuum Insulated Stainless Steel Food Canister Container with Leak Proof Lid
PFAS grade
Excellent 100/100
Overall grade
Excellent 88/100
Verdict
Buy
Hazard flags
⚑ 3
Material
Stainless steel body, silicone gasket lid seal
Confidence
82%
PossibleSilicone gasket degradation
PossibleBacterial growth in vacuum seal
PossibleSurface corrosion under acidic conditions
Monbento
MB Square Bento Box
PFAS grade
Good 70/100
Overall grade
Good 66/100
Verdict
Buy
Hazard flags
⚑ 1
Material
Polypropylene (PP) and stainless steel
Confidence
78%
PossibleMicroplastics from wear and heating
Where these two actually differ
- We flag Silicone gasket degradation, Bacterial growth in vacuum seal and Surface corrosion under acidic conditions on the Klean Kanteen and not on the Monbento.
- We flag Microplastics from wear and heating on the Monbento and not on the Klean Kanteen.
- The Klean Kanteen is Stainless steel body, silicone gasket lid seal where the Monbento is Polypropylene (PP) and stainless steel, which is most of the difference in these two grades.
- The gap is 30 points, wide enough that this is not a close call, and the Klean Kanteen is the one to buy.
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 lunch boxes: see the full ranking