50/ 100
F
OverallF28/100
20oz Double Wall Tumbler With Vacuum Sealer

Calpak · Insulated Drinkware Tumblers

20oz Double Wall Tumbler With Vacuum Sealer

F · High PFAS

Unknown internal coating composition. PFAS risk unclear without disclosure.

Verdict: SkipStainless steel construction is inherently safer than coated alternatives, but unspecified internal coating and brand silence on PFAS require cautious use and vendor clarification before purchase.

Calpak provides no detail on internal vacuum seal coating. Double-wall tumblers sometimes use Teflon-family coating liners; composition here unknown and undisclosed.

The safe swap

Contigo Byron 2.0 Stainless Steel Travel Mug Snapseal

Contigo

Contigo Byron 2.0 Stainless Steel Travel Mug Snapseal

95/100 safety

A

Still want this one anyway? Check the price on Amazon. We’d swap it.

Material

Double-wall stainless steel or similar, internal coating unspecified

Brand disclosure

Brand is silent on PFAS

Lab data

No public lab test

Why this grade

Unknown / proprietary coating

Proprietary coating with no disclosed chemistry.

Hurts the grade

Category baseline

other is a category where PFAS exposure is more common.

Hurts the grade

No PFAS disclosure

No public statement about PFAS in this product.

Hurts the grade

The full breakdown

What it's made of and why it matters

This tumbler uses double-wall stainless steel as its primary structure, which is chemically inert and does not leach metals under normal use. However, the critical unknown is the internal coating or sealant used to bond the double walls and create the vacuum seal. Many vacuum tumblers use polymer-based adhesives or thin interior coatings whose composition is not disclosed by Calpak. If that coating contains Teflon-type coating (Teflon-like) compounds or other Teflon-family coating, heating or damage could pose inhalation risks; if it contains epoxy or polyester resins, off-gassing of residual monomers is possible.

The brand's record and disclosure

Calpak is primarily known for luggage and travel goods rather than food-contact products, and no public certifications (FDA, NSF) or detailed material safety data are readily available for this specific tumbler. The brand has not published statements addressing PFAS, BPA, or internal coating composition. Without third-party testing reports or manufacturer transparency on adhesives and coatings, independent verification of safety claims is not possible from published sources.

How it compares in its category

Double-wall stainless steel tumblers are generally safer than plastic-lined or ceramic-coated alternatives in terms of leaching risk, provided the internal sealing method is non-toxic. This product is typical for the mass-market segment; higher-end competitors (Hydro Flask, YETI) often publish material certifications. Budget alternatives sometimes use cheaper adhesives with higher off-gassing potential. Calpak's position in the middle-to-budget range without transparency makes relative safety assessment difficult.

If you buy it

Avoid filling with boiling water immediately; allow a brief cool-down to reduce off-gassing from adhesives if present. Do not microwave or expose to sustained high heat, as this may degrade internal coatings. Inspect the interior regularly for corrosion, white film, or odors, which signal coating breakdown. Before first use, soak and rinse thoroughly with cool water. Contact Calpak customer service to request material safety data sheets (MSDS) for the internal coating and adhesive; if they cannot provide them, consider that a caution flag.

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.”

Possible

Internal adhesive or coating composition (unspecified)

Double-wall sealing typically requires polymer adhesives or thin coatings; Calpak does not disclose what is used. Off-gassing of residual monomers or volatile compounds is possible, especially with hot beverages, though risk depends entirely on the unknown formulation.

Possible

Teflon-type coating (Teflon-like) fume risk from internal coating

If the internal coating or adhesive is Teflon-family coating-based, mechanical damage (denting, scratching) or exposure to high heat could theoretically release fumes. No evidence this product uses Teflon-type coating, but the lack of disclosure prevents ruling it out.

None known

Stainless steel leaching (base material)

Stainless steel itself does not leach nickel, chromium, or molybdenum at room temperature or normal beverage pH. Risk is negligible unless the material is counterfeit or of extremely poor quality, which is unlikely from an established brand.

Possible

Coating degradation over time

The vacuum seal and any internal polymer coating can degrade with repeated hot fills, dishwasher use, or physical damage. Degradation could lead to condensation entry, mold growth in the gap, or exposure to breakdown products from the coating itself.

Reported

Microbial growth in vacuum gap if seal fails

Double-wall tumblers are known to develop mold or bacterial colonies in the insulating gap if the seal degrades and moisture enters. This is a maintenance and design limitation of the category, not specific to Calpak, but relevant to long-term safe use.

What we don’t know

This grade is a model-based estimate from public materials, coatings, and brand disclosure at 35% 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.

Safer alternatives in Insulated Drinkware Tumblers

Contigo Byron 2.0 Stainless Steel Travel Mug Snapseal

Contigo

Byron 2.0 Stainless Steel Travel Mug Snapseal

Stainless steel, silicone gasket

A
B
PFASAll
A · Very low PFAS3 flags

Travel mug with lower PFAS concern; stainless steel typically safe.

Bare metal or glass, no coating at all

Thermos Stainless King Travel Tumbler

Thermos

Stainless King Travel Tumbler

Stainless steel exterior, vacuum-insulated, minimal internal coating

A
B
PFASAll
A · Very low PFAS2 flags

Lower concern. Stainless steel tumbler with standard design, no PFAS-prone features.

Bare metal or glass, no coating at all

Thermos Stainless Steel Tumbler w/ Slide Lock Lid

Thermos

Stainless Steel Tumbler w/ Slide Lock Lid

Stainless steel tumbler with plastic slide lock lid

A
B
PFASAll
A · Very low PFAS2 flags

Lower concern. Stainless steel is PFAS-free; monitor lid material.

Bare metal or glass, no coating at all

More insulated drinkware 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.