Hydro Flask · Umbrellas
Rain Or Shine Umbrella Flask 2 Pack (24 Oz Total) - Hidden Alcohol
Lower PFAS concern for the flask itself; verify cap/seal materials separately.
Hydro Flask's core product is stainless steel, a PFAS-lower-concern material. However, caps, seals, and gaskets often contain proprietary elastomers or coatings whose PFAS status the brand does not publicly disclose.
Shop Hydro Flask on Amazon →Material
Stainless steel flask body (primary material)
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
Why this grade
Category baseline
clothing is a category where PFAS exposure is more common.
No PFAS disclosure
No public statement about PFAS in this product.
Uncoated safe material
Bare, uncoated material (cast iron, stainless, carbon steel, or glass) with no surface treatment to contain PFAS.
The full breakdown
What it's made of and why it matters
The primary vessel is 18/8 stainless steel, a corrosion-resistant alloy that does not leach metals into beverages under normal use. Stainless steel is chemically inert and one of the safest food-contact materials available. However, the cap, gasket, and seal materials are not specified in standard product listings and may include silicone, rubber, or plastics that could contain BPA, phthalates, or PFAS compounds used for water resistance.
The brand's record and disclosure
Hydro Flask is owned by Helen of Troy and is recognized for insulated drinkware but does not publicly disclose detailed material safety data or third-party certifications for non-stick coatings (not applicable to this product) or seal materials. The brand has not faced major recalls related to leaching or contamination in stainless steel flasks. No formal PFAS reduction commitment is documented in public statements, though the absence of Teflon-type coating in this model reduces one known PFAS vector.
How it compares in its category
Stainless steel flasks are considered safer than single-wall plastic alternatives because they eliminate BPA and phthalate leaching entirely. They are roughly equivalent to borosilicate glass in chemical safety but more durable. Most competitors in this price range (Yeti, Klean Kanteen, S'well) use identical 18/8 stainless construction; differentiation lies in cap materials and seal transparency, where Hydro Flask provides less public information than some rivals.
If you buy it
Inspect the cap and gasket materials before first use; contact Hydro Flask directly to confirm whether seals contain silicone or elastomers treated with PFAS water repellents. Hand-wash rather than dishwasher to reduce cap exposure to heat and extend seal life. Replace seals or caps if visible cracks, discoloration, or odors develop. The stainless steel body itself requires no special care and will not degrade chemically over normal use.
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.”
Cap and seal material composition (BPA/BPS/phthalates)
Hydro Flask does not publicly disclose elastomer or rubber formulations for caps and gaskets. Silicone and rubber compounds may contain BPA, BPS, or phthalates; verification requires direct manufacturer contact.
PFAS in cap/seal water-repellent coatings
Water-resistant seals in sport bottle caps commonly use PFAS-based fluorochemical coatings. Hydro Flask's silent stance on PFAS suggests seals have not been specifically tested or reformulated away from legacy compounds.
Stainless steel leaching (nickel, chromium)
18/8 stainless steel does not leach nickel or chromium under normal beverage storage conditions, even with acidic or alcoholic liquids. This material is considered safe for all food and drink contact by FDA and EU standards.
Seal degradation and microplastic shedding
Seals exposed to repeated hot-liquid fills or dishwasher cycles may degrade over time, potentially shedding microplastic particles. Risk increases if gaskets are made from lower-grade elastomers rather than medical-grade silicone.
Coating or adhesive off-gassing
Stainless steel does not require interior coatings or adhesive sealants in the flask body itself. No off-gassing risk from the vessel; only seals and cap glues present potential volatile compound exposure, not disclosed by the brand.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 72% 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.
More umbrellas 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.