Hydro Flask · Insulated Travel Mugs
Hydro Flask 24 oz Travel Tumbler
Lower concern. Stainless steel tumbler, no known PFAS use.
Hydro Flask travel tumblers use stainless steel construction with double-wall insulation. No PFAS-containing nonstick coatings or water-resistant treatments are disclosed.
The better-graded swap
Thermos
Thermos Stainless Steel Mug
80/100 safety
Same rubric that flunked this product. The swap earned Excellent.
Still want this one anyway? Check the price on Amazon. We’d swap it.
Material
Stainless steel double-wall insulation, no interior coating disclosed
Lab data
No public lab test
What Hydro Flask 24 oz Travel Tumbler is made of, ingredients and materials
The Hydro Flask 24 oz Travel Tumbler uses 18/8 stainless steel (chromium-nickel alloy) for both the inner and outer walls, separated by a vacuum or air-gap insulation layer. This material is inert in normal use and does not leach metals into beverages at typical serving temperatures. The lack of any disclosed interior polymer coating or non-stick finish eliminates common degradation pathways seen in coated tumblers, making it a chemically stable long-term container.
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.
Lid seal degradation and bacterial growth
The silicone or rubber gasket in the lid may degrade or trap moisture over years, potentially harboring bacteria if not cleaned regularly. This is a maintenance issue common to all sealed tumblers, not specific to Hydro Flask construction.
What’s reassuring
Base material not linked to PFAS
The main material recorded for this product is not one associated with PFAS.
Stainless steel corrosion and nickel leaching
Hydro Flask tumblers use food-grade 18/8 stainless steel, which is stable under normal beverage conditions. Nickel leaching is not reported for this product and occurs only under extreme acidic or chloride-rich conditions not typical of daily use.
Interior coating delamination or leaching
No interior polymer coating or enamel is disclosed for this tumbler, eliminating the risk of coating flaking or chemical leaching seen in coated alternatives. Bare stainless steel poses no coating hazard.
Thermal or pressure hazard from lid seal failure
The vacuum seal is designed to withstand normal beverage use but can fail if overtightened or damaged. No explosions or pressure incidents are established in public records for this model; standard care is sufficient.
Lead
Hydro Flask tumblers carry no reported heavy metal contamination or decorated surfaces with paint, glaze, or enamel that could harbor lead or cadmium. Bare metal construction avoids this hazard class entirely.
Source, ATSDR ↗The full breakdown
The brand's record and disclosure
Hydro Flask does not publicly disclose PFAS testing or stance, and the brand's material safety documentation is sparse for consumer review. No major product recalls or health controversies have been established for this tumbler line in available public records. The company is owned by Helen of Troy Limited and markets this product primarily on thermal performance rather than material safety certification.
How it compares in its category
Stainless steel tumblers with no interior coating disclosed show lower concern than ceramic-lined, polymer-coated, or Teflon-type coating-coated alternatives. This Hydro Flask model lacks any visible interior enamel, glaze, or non-stick layer, placing it lower-risk than budget tumblers with degradable coatings. Cost is higher than plastic or coated competitors, but material stability over years of use is well-established for bare stainless steel.
If you buy it
Hand-wash or use gentle dishwasher cycles to avoid potential seal degradation around the lid and insulation layer over time. Do not fill with boiling liquid immediately after opening from cold storage, as thermal shock may stress the seal. Replace the tumbler if the exterior shows corrosion pitting (rare but possible in very acidic or high-chloride environments) or if the lid seal fails and leaks. Stainless steel is durable for 5+ years of normal use; the lid gasket may need replacement first.
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
- Hydro Flask has made a specific claim
Formulations change between production runs, so check the current label. How we grade.
Better-graded alternatives in Insulated Travel Mugs
Owala
FreeSip Sway Stainless Steel
- Stainless steel body, no interior coating disclosed
- Silicone and plastic lid/valve leachables
3 hazards checked on this product. See all of them.
Owala
Stainless Steel Straw Tumbler Route 66
- Stainless steel tumbler, bare uncoated
- Coating degradation and microplastic shedding from exterior print
3 hazards checked on this product. See all of them.
Thermos
18 oz. Icon Vacuum Insulated Stainless Steel Mug
- stainless steel exterior, vacuum insulation, stainless steel interior
- We found no PFAS statement from the brand
- Nickel leaching from stainless steel
3 hazards checked on this product. See all of them.
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.