Ember · Insulated Travel Drinkware
Ember Cold Tumbler
Lower concern; stainless steel tumbler unlikely to contain PFAS.
Ember Cold Tumbler is primarily stainless steel with silicone gasket. No known PFAS coatings typical in this product category, though Ember does not explicitly address PFAS.
Shop Ember on Amazon →Material
stainless steel with silicone seal
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).
Category baseline
other is a category where PFAS exposure is more common.
The full breakdown
What it's made of and why it matters
The Ember Cold Tumbler is constructed from food-grade stainless steel (typically 18/8 or similar), which is chemically inert and does not leach metals under normal cold-beverage use. The silicone seal is a common food-contact elastomer that does not contain BPA or phthalates in modern formulations. Stainless steel tumblers are among the lowest-risk drinkware options because the metal does not corrode or degrade in contact with cold beverages, eliminating the leaching pathways seen in ceramic or aluminum alternatives.
The brand's record and disclosure
Ember is primarily known for temperature-control drinkware technology (heating elements, not relevant to cold tumbler chemistry). The brand has not published detailed material safety or PFAS disclosure statements publicly, and no major recalls or contamination incidents involving the cold tumbler line are documented. Without independent third-party certification (NSF, FDA clearance notices), material claims rely on typical industry standards for stainless steel food contact.
How it compares in its category
Stainless steel tumblers rank among the safest reusable drinkware options, on par with glass and superior to single-use plastics or coated ceramics in terms of leaching risk. Cold tumblers avoid the heating-related degradation hazards present in heated beverages or cookware. The main trade-off is that silicone seals can degrade faster than all-metal designs, but this affects function (spill prevention) rather than chemical safety.
If you buy it
Hand-wash the silicone seal and interior regularly to prevent microbial buildup, especially if left wet overnight. Do not expose to temperatures above 140°F (60°C) repeatedly, as silicone can slowly degrade under sustained heat. Replace the seal if it becomes noticeably discolored, stiff, or develops odor. Stainless steel itself is durable for years, but inspect for surface damage that could expose base metals.
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.”
Silicone seal degradation and microbial growth
Silicone gaskets can accumulate bacteria or mold if not cleaned thoroughly or dried completely between uses, particularly in crevices. This is a hygiene concern rather than a chemical hazard, but poor maintenance increases risk of cross-contamination.
Stainless steel nickel leaching
Food-grade stainless steel tumbler use with cold beverages presents negligible nickel leaching risk; nickel migration is primarily a concern with heating, extended acidic contact, or low-quality alloys. No reports of nickel sensitization from Ember cold tumblers are documented.
Manufacturing trace contaminants in seal material
Modern silicone used in food-contact applications is unlikely to contain heavy metals or volatile organic compounds at regulated levels, but independent testing of this specific product batch is not publicly available.
Coatings or adhesives on printed logos
If the tumbler has printed branding on the exterior, inks or adhesives could theoretically contain heavy metals or volatile compounds, but these do not contact beverages. Internal surfaces are typically unprinted.
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.
More insulated travel drinkware 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.