Hydro Flask · Insulated Travel Mugs
Hydro Flask 20-Ounce All Around Tumbler
Tumbler poses lower PFAS concern, no known risk signals.
Stainless steel interior with vacuum insulation and no reported PFAS-containing coatings or treatments. Brand doesn't disclose PFAS status, but composition carries inherently lower concern.
The better-graded swap
Owala
Owala Stainless Steel Straw Tumbler Route 66
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 interior, vacuum-insulated
Lab data
No public lab test
What Hydro Flask 20-Ounce All Around Tumbler is made of, ingredients and materials
The Hydro Flask 20-ounce tumbler uses food-grade stainless steel (typically 18/8 or 304-grade) for the interior and exterior, with a vacuum-sealed air gap for insulation and a plastic or silicone lid. Stainless steel is chemically inert in contact with beverages and foods and does not leach metals like aluminum, cadmium, or lead under normal use. The interior does not rely on enamels, glazes, or polymer coatings that degrade over time, eliminating a major source of contamination in conventional cookware.
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/gasket material degradation
The lid often contains silicone or plastic gaskets; extended UV exposure or dishwasher heat can cause minor breakdown, potentially shedding microparticles. This is a maintenance issue rather than a manufacturing defect.
What’s reassuring
Base material not linked to PFAS
The main material recorded for this product is not one associated with PFAS.
Aluminum leaching from exterior coating (if present)
The tumbler exterior is stainless steel and does not use aluminum. No leaching risk is documented for this specific product.
Stainless steel leaching
Food-grade stainless steel (304/18-8) is chemically stable in contact with water and acidic beverages at normal temperatures. No nickel or chromium leaching has been reported for Hydro Flask tumblers.
Teflon-type coating/nonstick coating fume risk
Stainless steel tumblers do not use Teflon-type coating (Teflon) coatings. This hazard does not apply to this product.
Microplastic shedding from interior surface
The interior is bare stainless steel, not polymer; no microplastics are released during normal use or heating.
The full breakdown
The brand's record and disclosure
Hydro Flask (owned by Helen of Troy Ltd.) has not publicly released detailed PFAS testing or a comprehensive chemical transparency statement. The company maintains basic food-contact compliance with FDA regulations for stainless steel vessels but does not voluntarily disclose third-party certifications such as NSF or B Corp. No recalls or reported safety incidents specific to the 20-ounce tumbler have been published; the brand's general reputation centers on durability rather than chemical rigor.
How it compares in its category
Stainless steel tumblers represent lower concern compared to ceramic-coated alternatives (which may contain lead or cadmium in glazes) or plastic-heavy designs. Vacuum-insulated stainless models from competing brands such as YETI and S'well share the same core material safety profile. The main differentiator is manufacturing quality and lid material rather than core toxicity risk; Hydro Flask is broadly consistent with category standards.
If you buy it
Hand wash or place on the top rack of the dishwasher to avoid any potential weakening of the vacuum seal over years of high-heat cycles. Inspect the lid gasket (typically silicone) annually for cracks or discoloration; replace if degraded to prevent mold or contamination. Avoid prolonged storage of acidic beverages (vinegar, citrus juice) in the same vessel for weeks, as even stainless steel can develop micro-pitting under extreme conditions. The product is designed for hot and cold beverages; standard use poses no elevated risk.
What we don’t know
- Basis
- Model estimate, 78% 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.