85/ 100
B
OverallC71/100
Corkcicle Go Cup XL 30oz Thyme

Corkcicle · Insulated Travel Mugs

Corkcicle Go Cup XL 30oz Thyme

B · Low PFAS

Lower concern. Stainless steel tumbler with standard plastics.

Verdict: BuyStainless steel body eliminates leaching risk; plastic components pose minimal hazard with normal use and proper care.

Corkcicle Go Cup uses stainless steel construction, a PFAS-free material. Plastic components (lid, gasket) carry typical contamination risk. Brand provides no PFAS disclosure.

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Material

Stainless steel body, plastic lid/gasket

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).

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

The Corkcicle Go Cup XL uses a 18/8 stainless steel body, which is highly resistant to corrosion and does not leach metals into beverages under normal conditions. The lid and gasket are made from standard engineered plastics (likely polypropylene or similar), which do not contain BPA in current manufacturing. Stainless steel is one of the safest material choices for reusable drinkware because it is non-reactive with acidic or hot liquids.

The brand's record and disclosure

Corkcicle does not publicly disclose detailed material sourcing or third-party safety certifications on their website. The brand has not faced documented recalls related to chemical leaching or contamination. No major safety controversies are on record for Corkcicle products, though the company maintains a silent stance on PFAS use in seals and gaskets, which is common in the drinkware industry.

How it compares in its category

Stainless steel tumblers are among the safest reusable drinkware options and outperform aluminum, coated steel, or plastic-only alternatives in terms of leaching risk. The Corkcicle Go Cup XL is competitively positioned within the insulated tumbler market and comparable in material safety to brands like Yeti and Hydro Flask. All three rely on standard plastic lids, which carry similar baseline risks across the category.

If you buy it

Hand wash the lid and gasket in warm soapy water after each use to prevent bacterial growth and mold in crevices. Do not expose the lid to the dishwasher if the manufacturer advises against it, as heat may degrade seals over time. The stainless steel body can handle hot and cold liquids safely; replace the gasket if it becomes visibly cracked or discolored. Store upside down when not in use to allow the interior to dry completely.

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

Plastic lid degradation and leaching

Standard plastic lids may degrade with repeated hot-liquid exposure or dishwasher use over years, though BPA is not used in modern Corkcicle lids. Replacement lids are available and should be swapped if cracking occurs.

Reported

Gasket bacterial/mold growth

Silicone or rubber gaskets can harbor bacteria and mold if not dried thoroughly between uses. This is a maintenance issue rather than a manufacturing defect and is common across all reusable drinkware with removable seals.

None known

Heavy metal leaching from stainless steel

18/8 stainless steel does not leach nickel, chromium, or other metals into beverages at safe pH levels. No recalls or complaints are on record for Corkcicle products on this hazard.

None known

Off-gassing or volatile organic compounds

Stainless steel does not off-gas; plastic components may emit minor VOCs when new, but exposure is negligible during normal use as a drink container.

None known

Coating or enamel failure

The stainless steel body has no applied coating or enamel, eliminating flaking or peeling risks. The exterior powder coat finish (if present) is not in contact with beverage.

What we don’t know

This grade is a model-based estimate from public materials, coatings, and brand disclosure at 72% 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.

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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.