YETI Rambler · Portable Water Bottles
YETI Rambler 36 oz Grasshopper
Low risk. Stainless steel and foam insulation unlikely PFAS sources.
YETI Rambler uses stainless steel with non-PFAS foam insulation. No brand PFAS statement, though materials carry lower risk than coated textiles.
We flunk more products than we pass. This one earned its grade. How we grade
Material
stainless steel inner; non-PFAS insulating foam
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
What YETI Rambler 36 oz Grasshopper is made of, ingredients and materials
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.
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.
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.
What’s reassuring
Base material not linked to PFAS
The main material recorded for this product is not one associated with PFAS.
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
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.
Source, FDA ↗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.
The full breakdown
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.
What we don’t know
- Basis
- Model estimate, 75% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- YETI Rambler has made none
Formulations change between production runs, so check the current label. How we grade.
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More portable water 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.