Lunch Food Box vs Ms. Bento Stainless Lunch Jar: which is safer?

Klean Kanteen Lunch Food Box is our pick: better on PFAS and on the overall hazard picture.

Our pick

Klean Kanteen Lunch Food Box

Klean Kanteen

Lunch Food Box

PFAS grade

Excellent 100/100

Overall grade

Excellent 88/100

Verdict

Buy

Hazard flags

⚑ 3

Material

stainless steel with bamboo fiber lid

Confidence

78%

PossibleBamboo fiber lid degradation or contaminant absorption

PossibleGasket or seal material composition

PossibleBamboo fiber formaldehyde or chemical treatment residue

Zojirushi Ms. Bento Stainless Lunch Jar

Zojirushi

Ms. Bento Stainless Lunch Jar

PFAS grade

Excellent 80/100

Overall grade

Good 72/100

Verdict

Buy

Hazard flags

⚑ 2

Material

Stainless steel body, polypropylene seals/lids

Confidence

82%

PossiblePolypropylene seal degradation under heat

PossibleMicroplastic generation from seal wear

Where these two actually differ

  • We flag Bamboo fiber lid degradation or contaminant absorption, Gasket or seal material composition and Bamboo fiber formaldehyde or chemical treatment residue on the Klean Kanteen and not on the Zojirushi.
  • We flag Polypropylene seal degradation under heat and Microplastic generation from seal wear on the Zojirushi and not on the Klean Kanteen.
  • The Klean Kanteen is stainless steel with bamboo fiber lid where the Zojirushi is Stainless steel body, polypropylene seals/lids, which is most of the difference in these two grades.

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 & food containers: see the full ranking