Thermos · Insulated Travel Mugs
Thermos 18 oz. Icon Vacuum Insulated Stainless Steel Mug
Lower concern; stainless steel mug has no water-repellent coating.
Thermos vacuum insulated mugs are stainless steel construction without non-stick or water-resistant coatings. No known PFAS treatment is involved in standard manufacturing.
We flunk more products than we pass. This one earned its grade. How we grade
Material
stainless steel exterior, vacuum insulation, stainless steel interior
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
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What Thermos 18 oz. Icon Vacuum Steel Mug is made of, ingredients and materials
The Thermos Icon is constructed from 18/8 stainless steel (both exterior and interior surfaces), which means it contains 18% chromium and 8% nickel as primary alloying elements. This alloy is passivated, forming a protective oxide layer that resists corrosion and prevents metal migration into beverages under normal use conditions. The vacuum insulation layer between walls contains no foam or added chemicals; it is created by the air gap itself, eliminating off-gassing concerns. No water-repellent coatings, Teflon-type coating liners, or ceramic enamels are used, removing the main coating-related hazards found in many drinkware products.
What’s concerning
Category baseline
The starting point for this type of product, before anything specific to this product is counted.
No PFAS disclosure
No public statement from the brand about PFAS in this product.
Nickel leaching from stainless steel
18/8 stainless steel does contain nickel (up to 8%). Under normal use with neutral pH beverages, leaching is minimal or not detectable; however, acidic or salty liquids stored for extended periods may elevate nickel release slightly. Risk is lowest among drinkware materials but not zero for individuals with severe nickel sensitivity.
Chromium leaching from stainless steel
Chromium in the passive oxide layer is typically hexavalent and immobilized; measurable leaching into beverages occurs only under extreme conditions (prolonged storage of very acidic liquids, abrasive damage to interior). Typical daily use with coffee, tea, or water poses negligible risk.
Thermal shock and seal degradation
Long-term vacuum integrity loss has been documented in user reviews and product durability studies for vacuum mugs, though this is a performance failure rather than a chemical safety hazard. Repeated temperature extremes (boiling water followed by freezing) accelerate seal breakdown.
What’s reassuring
Bare uncoated material
Recorded as a bare, uncoated material with no surface coating or treatment.
Coating degradation (none present)
No interior enamel, ceramic, or polymer coating is used in this model, eliminating risks of coating flaking or leaching that affect some competitors. This is a material advantage for safety.
Volatile organic compound off-gassing
Solid stainless steel and air-gap insulation produce no VOCs. No foam, adhesives, or polymer liners are present in the construction to release formaldehyde or other off-gases.
How is this PFAS grade calculated?
The brand's record and disclosure
Thermos (owned by Groupe SEB) has maintained a decades-long reputation for durable insulated drinkware with no public recalls related to leaching or coating failure for stainless steel models. The company does not prominently disclose PFAS testing or formal certifications (BPA-free, PFOA-free statements) on standard product pages, but the material composition itself (solid stainless steel, no polymer liners or coatings) makes intentional PFAS use highly unlikely. No controversies regarding hazardous substance violations are documented in FDA or Consumer Product Safety Commission records for this product line.
How it compares in its category
Among stainless steel vacuum mugs, the Thermos Icon represents a middle-ground option, simpler design than premium brands (Hydro Flask, Yeti) but more established longevity data than newer competitors. Unlike plastic-lined or ceramic-coated alternatives, it avoids microplastic shedding and enamel degradation hazards. It lacks the advanced food-contact certifications (NSF, California Proposition 65) that some premium competitors highlight, though the material chemistry itself has no hazard of this kind on record.
If you buy it
Hand wash only; dishwasher exposure can degrade the vacuum seal integrity over time. Do not fill with boiling liquid immediately after manufacture; let the mug acclimate to room temperature first to avoid seal stress. The stainless steel interior will not be harmed by acidic beverages (coffee, tea, lemon water) or hot temperatures up to 212°F. Replace if the exterior dents significantly, as this can compromise the vacuum layer and insulation performance; do not attempt to repair. Store dry to prevent residual odor absorption, and avoid prolonged contact with salt water or bleach-based cleaners.
What is not known about PFAS in this product?
- Basis
- Model estimate, 85% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- Thermos has made none
Formulations change between production runs, so check the current label. How we grade.
What are the PFAS-free alternatives to Thermos 18 oz. Icon Vacuum Insulated Stainless Steel Mug?
- stainless steel exterior, ceramic lining interior
- Ceramic coating degradation over time
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- Stainless steel body, plastic lid
- We found no PFAS statement from the brand
- Plastic lid polymer identity and leaching potential
3 hazards checked on this product, all on its full breakdown.
More insulated travel mugs 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.