50/ 100
F
OverallF28/100
Ember Mug 2

Ember · Insulated Travel Drinkware

Ember Mug 2

F · High PFAS

Unknown interior coating; Ember provides no PFAS disclosure.

Verdict: SkipStainless steel body is safe; interior coating composition undisclosed and untested publicly. Use cautiously pending transparency.

Ember Mug 2 uses stainless steel and electronics but does not disclose the composition of its proprietary interior heating/insulation coating. No public lab testing or brand PFAS claims available.

The safe swap

Ember Cold Tumbler

Ember

Ember Cold Tumbler

100/100 safety

A

Still want this one anyway? Check the price on Amazon. We’d swap it.

Material

Stainless steel body, electronic heating element, proprietary interior coating

Brand disclosure

Brand is silent on PFAS

Lab data

No public lab test

Why this grade

Unknown / proprietary coating

Proprietary coating with no disclosed chemistry.

Hurts 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 Ember Mug 2 uses food-grade stainless steel for its outer body and base, which does not leach metals under normal use. The critical unknown is the proprietary interior coating that contacts hot liquid repeatedly. Ember has not publicly disclosed the coating's chemical composition, making independent safety assessment impossible. Stainless steel itself is inert, but the coating's durability and contents determine actual safety.

The brand's record and disclosure

Ember has not published safety testing summaries, material certifications, or PFAS statements for the Mug 2 despite the product's sustained market presence since 2019. The company does not list third-party testing (NSF, FDA clearance, or similar) on its website. No product recalls related to coating failure, leaching, or heating element malfunction are publicly documented. Silence on coating composition is the primary transparency gap.

How it compares in its category

Smart mugs are a niche category with few competitors; most alternatives (Ember's first-gen mug, basic insulated drinkware) either avoid electronic heating or use simpler coatings. Standard insulated mugs typically use silicone gaskets and stainless interiors without electronic components, reducing chemical complexity. The Mug 2's embedded heating element and app control create a more complex product with more potential failure points and material interfaces. Comparable heated products (electric kettles, travel mugs with battery) more often disclose materials.

If you buy it

Do not expose to temperatures above the stated maximum (around 170°F / 77°C internal setting) to avoid coating stress. Hand wash only; dishwasher use could degrade the coating seal over time. Inspect the interior regularly for visible peeling, discoloration, or damage before each use. If the coating shows wear or the liquid acquires an off taste or odor, discontinue use and contact the company. Keep the mug away from abrasive scrubbing and acidic liquids (lemon water, vinegar) that may accelerate coating breakdown.

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

Proprietary interior coating leaching (unknown chemistry)

Ember's non-disclosure of coating material, composition, or safety testing means potential migration of coating components (polymers, additives, or cross-linkers) into hot beverages cannot be ruled out. Stainless steel itself is stable, but the coating is the direct contact point with liquid.

Reported

Coating degradation over time

User reports on product review sites (Amazon, Reddit) describe visible coating wear, flaking, or color fading after 1-3 years of regular use, though no formal recall has been issued. If coating degrades, both stainless steel exposure and loose coating particles become concerns.

Possible

Electronic heating element failure or water intrusion

The mug contains a lithium battery and heating circuit in the base; no public failure data exists, but water ingress from repeated hand washing or spill contact could cause short-circuit or electrolyte leakage. Warranty information does not clearly address accidental water damage scenarios.

Possible

Thermal injury from malfunctioning heating control

While the app-based temperature limit is a safety feature, firmware bugs or sensor failure could theoretically result in unexpected overheating. This is a mechanical/software risk rather than a chemical hazard but worth monitoring.

None known

Heavy metals in interior coating pigments (if present)

No testing or complaints of cadmium, lead, or chromium in the mug's interior finish are documented. However, absence of evidence is not certainty; Ember's lack of disclosure means heavy metal testing results are simply unavailable to consumers.

What we don’t know

This grade is a model-based estimate from public materials, coatings, and brand disclosure at 35% 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 Travel Drinkware

Ember Cold Tumbler

Ember

Cold Tumbler

stainless steel with silicone seal

A
A
PFASAll
A · Very low PFAS2 flags

Lower concern; stainless steel tumbler unlikely to contain PFAS.

Naturally PFAS-free material

Ember Tumblers - Set of 4

Ember

Tumblers - Set of 4

Stainless steel double-wall insulated

A
B
PFASAll
A · Very low PFAS3 flags

Lower PFAS concern; stainless steel drinkware rarely treated.

Naturally PFAS-free material

Ember Cup 14 oz Slate Black

Ember

Cup 14 oz Slate Black

Ceramic or ceramic-coated stainless steel with heated base

A
B
PFASAll
A · Very low PFAS2 flags

Lower concern. Smart cup uses ceramic coating, not Teflon-type coating nonstick.

Naturally PFAS-free material

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.