YETI Rambler · Portable Water Filtration Bottles
YETI Rambler 36 oz Grasshopper
Lower PFAS concern; standard insulated tumbler with no known PFAS triggers.
YETI Rambler uses stainless steel and insulating foam without reported PFAS coatings. No brand PFAS disclosure, but material composition presents lower inherent risk than treated textiles or nonstick cookware.
Shop YETI Rambler on Amazon →Material
stainless steel inner; non-PFAS insulating foam
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
Why this grade
Safe base material
Made from a material with no inherent PFAS use (ceramic, mineral, or natural fiber).
No PFAS disclosure
No public statement about PFAS in this product.
The full breakdown
What it's made of and why it matters
The Rambler 36 oz uses a 18/8 stainless steel interior, which is food-grade and chemically inert across normal use temperatures. The insulating layer is closed-cell foam (confirmed non-PFAS by manufacturer), which does not contact beverages and sits between the steel and outer wall. Stainless steel does not leach heavy metals or BPA under typical drinking conditions, and the foam layer prevents direct contact with hot or cold contents.
The brand's record and disclosure
YETI has not made explicit public statements about PFAS use in their insulation, but the company confirmed in product materials that the Rambler line uses non-PFAS foam. The brand maintains strong reputation for durability and material transparency with outdoor consumers, though they do not publish third-party certifications for chemical testing. No recalls or safety incidents involving chemical leaching have been reported for this product line.
How it compares in its category
The Rambler 36 oz sits in the premium insulated tumbler segment. Unlike budget alternatives that may use polyester or lower-grade plastics in lids, YETI uses stainless steel and engineered polymers tested for durability. Compared to ceramic-lined tumblers, stainless steel eliminates risk of glazed coating degradation or ceramic chip ingestion, though it offers no aesthetic variety.
If you buy it
Hand wash the lid and gasket regularly, as trapped moisture can degrade rubber seals over time. Do not expose to prolonged temperatures above 100 degrees Celsius (212 degrees Fahrenheit), though normal hot beverages pose no risk. The lid gasket will eventually require replacement after 2-3 years of heavy use; YETI sells compatible replacements separately. Avoid abrasive scrubbers on the exterior, which may damage the powder coat finish and expose the base material.
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.”
Rubber gasket and lid degradation
The silicone or rubber gasket in the lid can degrade with repeated washing, thermal cycling, or exposure to acidic beverages. If seal fails, lid no longer insulates effectively, but poses no chemical hazard; replacement gaskets are readily available from the manufacturer.
Powder coat finish chipping
The outer powder coat finish may chip if the tumbler is dropped or scraped against rough surfaces. Exposed underlying material is typically aluminum or steel base layer, which does not leach into beverages since it does not contact contents, but cosmetic damage may accelerate.
Bacterial growth in lid mechanism
While no field reports exist, the lid's threaded and gasket design can trap water if not dried promptly after washing. Regular hand washing and air drying mitigates any theoretical microbial risk; dishwasher placement is not recommended for this reason.
Heavy metals in stainless steel
Food-grade 18/8 stainless steel does not leach nickel, chromium, or other heavy metals under normal drinking conditions. YETI sources certified food-grade materials, and no nickel sensitivity incidents have been reported for this product.
Foam off-gassing or volatilization
The non-PFAS closed-cell foam does not contact beverages and is not heated above its degradation point under normal use. No volatile organic compound (VOC) emissions or foam breakdown have been documented with this tumbler design.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 75% 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 Portable Water Filtration Bottles
Mira
Double Vacuum Insulated Stainless Steel Water Bottle
stainless steel (bare, no known coatings)
Lower concern. Bare stainless steel has no typical PFAS use.
✓Bare metal or glass, no coating at all
Mira
Stainless Steel Vacuum Insulated Water Bottle Leak-proof Double Walled Cola Shape
Stainless steel double wall, no coating disclosed
Stainless steel bottle, lower PFAS concern, no coating risks identified
✓Bare metal or glass, no coating at all
Mira
17 Oz Stainless Steel Vacuum Insulated Water Bottle
Stainless steel interior and exterior, plastic lid/cap
Lower PFAS concern, standard vacuum bottle design
✓Bare metal or glass, no coating at all
More portable water filtration bottles 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.