Ember · Insulated Drink Tumblers
Ember Cold Tumbler
Lower concern; stainless steel tumbler unlikely to contain PFAS.
Ember's Cold Tumbler is stainless steel with silicone seals and no known PFAS coatings typical of this product type. Ember doesn't address PFAS explicitly.
We flunk more products than we pass. This one earned its grade. How we grade
Material
stainless steel with silicone seal
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
What Ember Cold Tumbler is made of, ingredients and materials
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.
What’s concerning
No PFAS disclosure
No public statement from the brand about PFAS in this product.
Category baseline
The starting point for this type of product, before anything specific to this product is counted.
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.
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’s reassuring
Base material not linked to PFAS
The main material recorded for this product is not one associated with PFAS.
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.
The full breakdown
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 are not a material linked to PFAS, similar to glass and showing lower concern than 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.
What we don’t know
- Basis
- Model estimate, 72% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- Ember has made none
Formulations change between production runs, so check the current label. How we grade.
Better-graded alternatives in Insulated Drink Tumblers
Klean Kanteen
20oz TKWide with Café Cap, Tofu
- Stainless steel bottle, stainless steel cap
- The brand calls it PFAS-free, which we have not verified
- Powder-coat cap degradation over time
3 hazards checked on this product. See all of them.
Klean Kanteen
16oz Rise Tumbler
- Stainless steel body, powder-coat finish
- The brand calls it PFAS-free, which we have not verified
- Powder-coat finish degradation
3 hazards checked on this product. See all of them.
Klean Kanteen
Insulated TKWide Cap
- Stainless steel bottle, plastic cap and silicone gasket
- The brand calls it PFAS-free, which we have not verified
- Silicone gasket degradation and leaching
3 hazards checked on this product. See all of them.
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.