95/ 100
A
OverallB83/100
40oz Stainless Steel Tumbler

Calpak · Insulated Drinkware Tumblers

40oz Stainless Steel Tumbler

A · Very low PFAS

Lower PFAS concern. Bare stainless steel has no coating risk.

Verdict: BuyBare stainless steel tumbler with no coating eliminates most chemical leaching risks; minimal brand disclosure but material itself is inherently safe.

Stainless steel tumblers are inherently lower concern for PFAS, as the material contains no fluorochemical coatings. Calpak does not disclose PFAS information; uncoated stainless remains a safer choice.

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Material

Stainless steel, bare uncoated

Brand disclosure

Brand is silent on PFAS

Lab data

No public lab test

Why this grade

Uncoated safe material

Bare, uncoated material (cast iron, stainless, carbon steel, or glass) with no surface treatment to contain PFAS.

Helps 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 is constructed from uncoated stainless steel, a chromium-iron alloy that resists corrosion without requiring protective coatings. Unlike ceramic tumblers with glazes or double-walled plastic alternatives, bare stainless steel has no polymer binders, enamels, or finish layers that can degrade and release contaminants. The material is inert across normal use temperatures (hot and cold beverages) and does not leach significant quantities of chromium or nickel under typical conditions, though minor surface interactions with acidic drinks over years remain theoretically possible but unmeasured for this specific brand.

The brand's record and disclosure

Calpak is known primarily for luggage and travel accessories; public disclosure on manufacturing standards, material testing, or chemical safety for this drinkware product is minimal to absent. No major recalls or safety controversies are on record for Calpak stainless steel tumblers. The brand's silence on PFAS and other hazard mitigation suggests a lack of third-party certification or transparent testing, though it does not indicate the presence of hazards.

How it compares in its category

Bare stainless steel tumblers are among the safest insulated drinkware options; they avoid coating-related risks (Teflon-type coating, lead, BPA) that plague some ceramic and plastic alternatives. Most competitors in the 40oz category (Hydro Flask, YETI, Contigo) use similar stainless steel construction with epoxy or powder-coat exterior finishes that may pose minor off-gassing or durability concerns. Calpak's uncoated approach is straightforward and low-risk, though it sacrifices color variety and aesthetic design options.

If you buy it

Hand wash with mild soap to avoid harsh dishwasher detergents that may pit the surface over extended use. Acidic beverages (lemon water, vinegar-based drinks) can cause minor corrosion over months if left sitting; rinse promptly. Replace only if dents compromise insulation or sealing capability, or if visible rust develops (rare but possible with poor care). Store dry and avoid abrasive scrubbing pads that damage the finish.

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

Nickel leaching (stainless steel alloy)

Stainless steel contains nickel as an alloying element; migration into beverages is minimal in neutral-pH drinks but slightly elevated in acidic or salt-heavy liquids. No brand-specific testing available for Calpak tumbler; industry standard 304/316 grades rarely exceed safe limits under normal use.

Possible

Lid gasket and seal degradation

If the tumbler includes silicone or rubber gaskets (common in insulated tumblers), these may contain BPA or phthalates depending on supplier. No information on Calpak's gasket sourcing is publicly available; inspect for off-odors or cloudiness indicative of degradation.

Possible

Bacterial or mold growth in insulation gap

Double-walled stainless steel construction can trap moisture in the insulation cavity if not properly sealed or if capillary action allows liquid to enter. This is a practical maintenance issue rather than chemical hazard but can result in internal corrosion or odor over years if the seal fails.

None known

Coating or adhesive residue (interior sealing)

Bare stainless steel eliminates exterior coating risk, but if the interior features any epoxy or food-grade sealant (rare), off-gassing is possible. Calpak's product documentation does not specify interior treatment; assume bare metal unless marked otherwise.

None known

Surface contamination or manufacturing residue

Uncoated stainless steel tumblers may retain processing oils, metal dust, or cleaning agent residue from manufacturing. No recalls or contamination reports exist for Calpak; standard practice is a hot-water rinse before first use as a precaution.

What we don’t know

This grade is a model-based estimate from public materials, coatings, and brand disclosure at 78% 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 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.