Yeti · Insulated Drink Tumblers & Travel Mugs
YETI Rambler 20 oz Stackable Cup
Low-Medium risk. Stainless steel cup with no known PFAS risk. Brand silent on PFAS.
This YETI cup is stainless steel with no disclosed nonstick or water-resistant coating. No public PFAS concerns exist, but the brand stays silent.
The safe swap
Yeti
Rambler Tumbler YETI
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 cup body
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
What’s concerning
Category baseline
PFAS exposure happens more often with clothing products.
No PFAS disclosure
The company has not publicly discussed PFAS in this product.
Silicone gasket degradation and microbial growth
Gaskets in insulated lids can harbor mold or bacterial biofilm if not dried thoroughly after each use or stored wet; replacement gaskets are inexpensive and widely available but not always user-accessible on all Rambler models.
What’s reassuring
Safe base material
Made from ceramic, mineral, or natural fiber with no PFAS risk.
Stainless steel leaching
18/8 stainless steel does not leach nickel, chromium, or iron in measurable amounts to food or beverage under normal use conditions; no reported incidents in this product line.
Coating degradation (enamel, glaze, ceramic)
Interior has no applied coating, eliminating risks of chipping, peeling, or particulate shedding; exterior powder coat is not in food contact.
Teflon-type coating (Teflon) fume risk
No Teflon-type coating layer is present in this drinkware; this hazard is not applicable to stainless steel construction.
Aluminum leaching (if present)
Rambler 20 oz body is stainless steel, not aluminum; no aluminum-contact risk in this specific model variant.
The full breakdown
What it's made of and why it matters
The Rambler 20 oz uses 18/8 stainless steel (304 grade) as its primary food-contact surface, which is corrosion-resistant and chemically stable under normal use. Stainless steel does not leach metals like lead or cadmium because these elements are not components of the alloy in food-contact amounts. The interior has no ceramic glaze, enamel coating, or Teflon-type coating (Teflon) layer, which eliminates the primary degradation and fume risks associated with coated cookware. The lid and any gaskets may use silicone or polypropylene, materials with minimal leaching risk at cold and room temperature.
The brand's record and disclosure
Yeti does not publicly disclose manufacturing methods, material certifications, or chemical testing for this product line. The brand has faced no major product safety recalls or published health complaints specific to the Rambler cups. Yeti maintains FDA food-contact material compliance as a baseline but has not pursued third-party certifications (e.g., NSF, BPA-Free verification) that would provide independent safety assurance. The brand's silence on PFAS and other chemical disclosures is consistent with many outdoor product manufacturers but limits transparency for cautious buyers.
How it compares in its category
Insulated drinkware in this price range (typically 40-50 USD) commonly uses stainless steel bodies; Yeti is not an outlier in material choice. Competing brands like Hydro Flask and S'well use similar 18/8 stainless steel with comparable lid designs, so chemical hazard profiles are largely equivalent across the category. Lower-cost alternatives sometimes use plastic liners or painted finishes that carry higher leaching risk; higher-end brands rarely offer additional safety testing. Yeti's reputation for durability is well-earned, which indirectly reduces replacement frequency and long-term exposure risk.
If you buy it
Stainless steel Ramblers tolerate hot and cold beverages without coating degradation and do not require seasoning or special care like coated cookware. Hand wash or top-rack dishwasher cleaning is safe; avoid abrasive scrubbers that could scratch the exterior but will not compromise food safety. The silicone gasket should be inspected annually for mold or odor and replaced if damaged, as this is the only component with potential contamination risk after years of use. This product is not primarily designed for cooking or direct heat; use only for beverage storage at temperatures up to boiling for hot liquids.
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
- Yeti has made none
Formulations change between production runs, so check the current label. How we grade.
Safer alternatives in Insulated Drink Tumblers & Travel Mugs
Yeti
Rambler Tumbler YETI
18/8 stainless steel, no coating
Nickel leaching from stainless steel
Limited concern
Low risk. Bare stainless steel tumbler with no known PFAS risk.
⚠Risky category by default
Contigo
Autoseal West Loop Stainless Steel Travel Mug
stainless steel body, silicone gasket/lid seal
Silicone gasket degradation and bacterial/mold colonization
Limited concern
Low-Medium risk. Stainless steel and silicone have minimal PFAS risk.
⚠Risky category by default
Contigo
Cortland Chill 2.0 Stainless Steel Water Bottle
stainless steel, no reported coating
Gasket and seal degradation
Limited concern
Bacterial growth in inaccessible spaces
Limited concern
Thermal stress and seal failure
Limited concern
Low-Medium risk. Bare stainless steel bottle with no known problematic coatings.
⚠Risky category by default
More insulated drink tumblers & 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.