Corkcicle · Insulated Drink Tumblers
CORKCICLE TUMBLER
Lower concern. Stainless steel body and plastic parts with no disclosed coating.
The tumbler's double-wall stainless steel is not a material linked to PFAS. The plastic lid and plug materials are not disclosed by the brand, and no water-repellent finish is on record.
We flunk more products than we pass. This one earned its grade. How we grade
Material
Double-wall stainless steel with plastic lid/plug
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
What’s concerning
Category baseline
The starting point for this type of product, before anything specific to this product is counted.
No PFAS disclosure
No public statement from the brand about PFAS in this product.
Plastic lid/plug composition and leaching
The material identity and manufacturing process of the plastic lid and plug are not disclosed. While brief ambient-temperature contact is low-risk, long-term storage of acidic beverages or warm liquids in contact with the seal could present minor leaching risk if low-quality or recycled polymer is used.
Bacterial growth in double-wall seal or drainage holes
If the tumbler has a drainage port or the seal becomes compromised, water or beverage residue can accumulate in the gap between walls, promoting mold or bacterial growth. Regular inspection and thorough drying after washing will mitigate this risk.
What’s reassuring
Base material not linked to PFAS
The main material recorded for this product is not one associated with PFAS.
Teflon-type coating or non-stick coating on stainless steel
Corkcicle does not market a non-stick coating on the tumbler interior. Standard stainless steel without additional surface treatment is used, so Teflon-type coating fume risk does not apply.
BPA & bisphenols
Corkcicle does not explicitly state that lids and plugs are BPA-free or phthalate-free. However, FDA regulations restrict BPA in food-contact plastics, and modern food-grade polypropylene typically avoids phthalates; no reported contamination cases for this product exist.
Source, FDA ↗Stainless steel nickel/chromium leaching
Stainless steel is passivated and does not leach nickel or chromium into neutral or acidic beverages under normal conditions. Double-wall construction further isolates the inner surface from wear. No leaching has been reported for this product type.
The full breakdown
What it's made of and why it matters
The Corkcicle Tumbler features a double-wall stainless steel core, which is chemically inert and does not leach metals or compounds into liquids under normal use. The lid and plug are plastic components, likely polypropylene or similar food-contact polymer, but they do not remain submerged and contact is brief and ambient-temperature. Double-wall construction also means the inner stainless steel wall is the only surface touching your beverage, insulating it from exterior degradation.
The brand's record and disclosure
Corkcicle does not publicly disclose PFAS testing results, use, or avoidance statements for this product line. The brand markets as a lifestyle drinkware company with emphasis on sustainability and design rather than toxicology transparency. No major recalls or safety controversies involving this specific tumbler model are on public record. The brand has not sought third-party safety certifications (e.g., FDA food-contact clearance statements) prominently.
How it compares in its category
Stainless steel tumblers are among the lowest-risk reusable drinkware options because the material itself does not leach. Corkcicle's double-wall design is standard for insulated tumblers and poses no added hazard. Competitors like Hydro Flask and S'well use similar stainless steel construction, so this product is materially comparable. The main variable across brands is plastic lid composition and PFAS treatment, which Corkcicle has not disclosed.
If you buy it
Wash the lid and plug by hand or on the top rack of the dishwasher to avoid plastic degradation; avoid prolonged boiling water contact with plastic parts. Do not fill with liquids hotter than 160F if you are concerned about leaching from the plastic seal, though stainless steel itself has no temperature limit. Replace the lid or plug if cracking, discoloration, or odor develops. Stainless steel body is durable and will not degrade with normal use or dishwashing.
What we don’t know
- Basis
- Model estimate, 72% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- Corkcicle has made none
Formulations change between production runs, so check the current label. How we grade.
Better-graded alternatives in Insulated Drink Tumblers
Klean Kanteen
16oz Rise Tumbler
Stainless steel body, powder-coat finish
Powder-coat finish degradation
Limited concern
Seal degradation and microbial growth
Limited concern
Thermal shock to seals
Limited concern
Brand PFAS statement on record, which we have not verified.
⚠Starting grade for this product type
Klean Kanteen
Rise Tumbler
18/8 stainless steel body, likely stainless steel or silicone lid
Nickel leaching from stainless steel
Limited concern
Silicone lid degradation
Limited concern
Brand PFAS statement on record, which we have not verified.
⚠Starting grade for this product type
Klean Kanteen
20oz TKWide with Café Cap, Tofu
Stainless steel bottle, stainless steel cap
Powder-coat cap degradation over time
Limited concern
Bacterial biofilm in cap threads and seals
Limited concern
Thermal stress on seals at extreme temperatures
Limited concern
Brand PFAS statement on record, which we have not verified.
⚠Starting grade for this product type
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.