27oz Wide Water Bottle with Loop Cap vs Classic Flip Seal Sport Cap: which is safer?

Klean Kanteen 27oz Wide Water Bottle with Loop Cap is our pick: better on PFAS and on the overall hazard picture.

Our pick

Klean Kanteen 27oz Wide Water Bottle with Loop Cap

Klean Kanteen

27oz Wide Water Bottle with Loop Cap

PFAS grade

Excellent 100/100

Overall grade

Excellent 88/100

Verdict

Buy

Hazard flags

⚑ 3

Material

18/8 stainless steel, no interior coating

Confidence

92%

PossibleNickel leaching from stainless steel

PossibleSurface corrosion and pitting over time

PossibleBacterial growth in cap seals

Klean Kanteen Classic Flip Seal Sport Cap

Klean Kanteen

Classic Flip Seal Sport Cap

PFAS grade

Excellent 95/100

Overall grade

Excellent 83/100

Verdict

Buy

Hazard flags

⚑ 3

Material

Stainless steel bottle, plastic flip cap

Confidence

78%

PossiblePlastic cap degradation and microparticles

PossibleCap seal/gasket off-gassing or contamination

PossibleBacterial growth in cap crevices

Where these two actually differ

  • We flag Nickel leaching from stainless steel, Surface corrosion and pitting over time and Bacterial growth in cap seals on the Klean Kanteen and not on the Klean Kanteen.
  • We flag Plastic cap degradation and microparticles, Cap seal/gasket off-gassing or contamination and Bacterial growth in cap crevices on the Klean Kanteen and not on the Klean Kanteen.
  • The Klean Kanteen is 18/8 stainless steel, no interior coating where the Klean Kanteen is Stainless steel bottle, plastic flip cap, which is most of the difference in these two grades.
  • These two are 5 points apart, close enough that price and fit should decide it rather than our 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 portable water bottles: see the full ranking