Cuppa · Insulated Drink Tumblers
Copper Stainless Steel Water Glass Tumbler
Lower concern. Bare metal and glass drinkware, no coatings flagged.
Copper and stainless steel tumblers are inherently PFAS-free materials with no intentional coatings requiring PFAS. No brand disclosure on PFAS, but material composition poses minimal risk for drinking vessels.
We flunk more products than we pass. This one earned its grade. How we grade
Material
Copper, stainless steel, borosilicate glass
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.
Category baseline
other is a category where PFAS exposure is more common.
No PFAS disclosure
No public statement about PFAS in this product.
The full breakdown
What it's made of and why it matters
This tumbler combines three inert materials: borosilicate glass (a heat-resistant, chemically stable glass), 304/316-grade stainless steel (typically the container or inner lining), and copper (likely an exterior or decorative layer). Borosilicate glass does not leach into beverages under normal use because it is chemically inert and does not break down at drinking temperatures. Stainless steel is passive when properly passivated at manufacture, meaning a protective oxide layer prevents metal ions from entering liquids. Copper, when in contact with acidic or very hot beverages, can theoretically leach small amounts, but the risk is negligible with stainless steel or glass as a barrier.
The brand's record and disclosure
Cuppa maintains a minimal public safety disclosure stance; no third-party certifications (NSF, FDA compliance statements) or detailed material sourcing information is publicly documented. No recalls, complaints, or testing failures are on record for this specific product model. The brand does not advertise lead-free or PFAS-free credentials, though the material choice (no coatings) makes such claims less critical than they would be for non-stick or glazed cookware. Without independent audit history, safety assessment relies on inherent material properties rather than brand reputation.
How it compares in its category
Uncoated metal and glass tumblers are among the safest drinkware choices because they eliminate leaching pathways common in ceramics with glazes, enamel-coated metals, and plastic alternatives. Ceramic or enamel-coated tumblers carry small lead or cadmium risks in glazes; plastic tumblers risk BPA or phthalate migration if heated. Copper exterior aesthetic appeals to consumers but offers no functional advantage over plain stainless steel and introduces negligible copper leaching risk if not the primary contact surface. This design prioritizes durability and chemical stability over non-stick convenience or decorative coatings.
If you buy it
Hand wash rather than dishwasher to preserve the copper finish and avoid corrosion at seams where stainless and copper meet; dishwasher cycles can accelerate galvanic corrosion. Use with room-temperature to warm (not boiling) beverages to minimize any theoretical copper leaching, though this risk is very low with a glass or steel barrier. Inspect annually for pitting or discoloration on the copper exterior; if deep corrosion develops near seams, replacement is prudent to prevent stainless steel exposure. Do not store acidic liquids (lemon water, vinegar solutions) for extended periods, as acidity can accelerate copper surface degradation over years of use.
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.”
Copper leaching
Copper exterior may shed trace amounts under prolonged contact with acidic or very hot liquids, though a glass or stainless interior acts as a barrier. Risk is minimized if copper is purely decorative and not the primary contact surface; confirm product design before purchase if concerned.
Galvanic corrosion at metal seams
Copper and stainless steel in contact with water and electrolytes (minerals in tap water, beverages) can corrode over years through electrochemical reaction. This degrades appearance and durability but does not directly contaminate beverages if internal surfaces remain intact.
Borosilicate glass thermal shock
Borosilicate glass is highly heat resistant but can crack if exposed to extreme temperature swings (e.g., ice-cold liquid followed immediately by boiling water). Risk is low in typical daily use but should be avoided.
Lead or cadmium in metal plating or adhesives
No documented cases or recalls of lead or cadmium contamination in Cuppa stainless-copper tumblers. Plating and adhesives are not typically flagged for this material combination, though third-party testing is absent.
Microplastics or off-gassing
Glass, stainless steel, and copper do not off-gas volatile organics or shed microplastics. This product poses no VOC or microplastic risk by material class.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 85% 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 Drink Tumblers
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✓Naturally PFAS-free material
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✓Bare metal or glass, no coating at all
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.