Klean Kanteen · Insulated Drink Tumblers
Klean Kanteen 10oz Rise Lowball Tumbler
Lower PFAS concern. Bare stainless steel construction, no coatings flagged.
Klean Kanteen tumblers use vacuum-insulated stainless steel without reported nonstick or water-resistant coatings. No PFAS signals detected in public materials or brand disclosures.
We flunk more products than we pass. This one earned its grade. How we grade
Material
Double-wall vacuum insulated stainless steel
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
Why this grade
Safe base material
Made from a material with no inherent PFAS use (ceramic, mineral, or natural fiber).
Category baseline
other is a category where PFAS exposure is more common.
The full breakdown
What it's made of and why it matters
This tumbler uses food-grade 18/8 stainless steel (chromium-nickel alloy) for both inner and outer walls, separated by a vacuum layer for insulation. The vacuum seal itself contains no chemical coatings, adhesives, or polymer liners that would leach into beverages. Stainless steel is chemically inert under normal use and does not degrade with hot or cold liquids, making it one of the safest food-contact material classes.
The brand's record and disclosure
Klean Kanteen has a documented commitment to material transparency and avoids PFOA/PFAS-based water-resistant coatings in its product line. The brand publicly emphasizes bare metal and glass construction and has faced no recalls or safety controversies on its core drinkware products. Company materials consistently specify stainless steel grade and do not list chemical coatings or linings as product components.
How it compares in its category
Vacuum-insulated stainless steel tumblers are among the safest reusable drinkware options available. Unlike ceramic tumblers (which may have lead or cadmium in glazes), polymer-lined alternatives (which risk BPA or phthalate leaching), or coated metals (which can degrade), bare stainless steel avoids these classes of concern entirely. This product sits at the low-hazard end of the insulated drinkware spectrum.
If you buy it
Hand-wash or use a bottle brush to avoid dishwasher damage to the vacuum seal over time. Do not freeze beverages in it, as expansion can stress the seal. The stainless steel exterior will show fingerprints and minor cosmetic wear but poses no safety risk. Check the lid seal annually; if it deteriorates, replacement lids are available and inexpensive.
Beyond PFAS: other things we checked
Established hazard classes for this product type, assessed from public information. These never change the PFAS grade; a Likely flag caps the Verdict at “Buy with care.”
Vacuum seal degradation
The vacuum insulation bond between inner and outer steel walls may weaken with age or repeated thermal stress, though this is a functional failure (loss of insulation) rather than a safety hazard. No chemical leaching is associated with seal failure.
Lid material composition
The tumbler lid likely contains silicone or plastic gaskets and a closure mechanism; Klean Kanteen does not publicly disclose BPA or phthalate concerns for its lid components, and no recalls on this product line have been issued for lid-related chemical contamination.
Metal leaching from stainless steel
18/8 stainless steel is highly corrosion-resistant and does not leach nickel, chromium, or iron at pH levels found in food and beverages under normal storage. Leaching risk is effectively zero unless the steel is scratched and exposed to high-acid liquids for extended periods.
Thermal stress or lid detachment
Rapid heating or freezing may stress the seal or cause the lid to loosen, but this is a functional and usage risk rather than a chemical safety concern. Use within normal beverage temperature ranges to minimize stress.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 82% confidence. It is not a lab result.
No independent PFAS lab test is on record for this exact product. A lab test could move the score in either direction.
The brand has not made a specific, verifiable PFAS-free statement, so part of this score reflects that missing disclosure rather than a confirmed material.
Formulations and coatings change between production runs. Always check the current label before buying.
More insulated drink tumblers grades
How we score: every product runs through the same public 0–100 rubric based on materials, coatings, brand disclosure, lab findings, and recalls. See the full methodology → Spotted a mistake? Report an error.