Clearly Filtered · Filtered Water Bottles
40oz Insulated Stainless Steel Filtered Water Bottle
Lower PFAS concern for the steel body; filter cartridge composition requires brand clarification.
The 40oz stainless steel insulated bottle itself poses lower PFAS risk, stainless steel is a stable, non-coated material. However, the filtered water bottle's cartridge composition (carbon source, binder, and any membranes) is not publicly documented by Clearly Filtered. No PFAS claims or third-party testing data are publicly available.
Shop Clearly Filtered on Amazon →Material
Stainless steel body; carbon/activated carbon filter cartridge
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
Why this grade
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 40oz body is 18/8 stainless steel, which is highly resistant to corrosion and does not leach heavy metals or BPA under normal use. The filter cartridge uses activated carbon, a porous form of carbon that adsorbs contaminants; this material itself is inert when food-grade. The critical unknown is what binder, resin, or structural material holds the carbon particles together inside the cartridge, manufacturers rarely disclose this, and some use phenolic resins or epoxy that could theoretically release trace compounds if saturated or heated.
The brand's record and disclosure
Clearly Filtered markets itself as PFAS-focused but provides minimal public disclosure on cartridge construction, manufacturing standards, or third-party testing of the filter housing itself. No major recalls or safety incidents are on record for this product line. The brand does not appear to hold NSF or WQA certification for the filter cartridge, which would provide independent verification of contaminant removal claims and material safety.
How it compares in its category
Filtered water bottles in this size range typically use either activated carbon (as here) or ion-exchange resin cartridges. Clearly Filtered's stainless steel body is stronger and safer than plastic-bodied competitors (which carry BPA/microplastic risk if degraded). However, competitors like Berkey or ZeroWater publish more detailed filter specifications and independent test reports; Clearly Filtered lags in transparency for the cartridge itself.
If you buy it
Replace the filter cartridge every 2-3 months or per manufacturer guidance to prevent bacterial growth and saturation-induced leaching. Do not expose the cap or cartridge housing to heat above 140F, as this can stress seal materials and resins. Store filled bottles at room temperature away from direct sunlight; freezing is safe but may stress seals over time. Rinse the cartridge under cold water before first use to remove carbon dust.
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.”
Filter cartridge binder/resin leaching
Activated carbon cartridges often use phenolic resin, epoxy, or melamine-formaldehyde as structural binders; manufacturer does not publicly specify which. If cartridge is oversaturated or subjected to temperature stress, trace leaching is theoretically possible but has not been reported for this brand.
Bacterial colonization in filter
Activated carbon filters can harbor bacterial growth if not replaced regularly or if bottle sits unused for weeks. This is a maintenance risk, not a design defect, but applies to all carbon-filter bottles in this category.
Cap/seal material off-gassing
Most 40oz bottles use polypropylene (PP) or silicone caps and seals. Clearly Filtered does not disclose cap material publicly; no safety issues are documented for this model, but cold-resistant silicone is preferable to PP if long-term leaching is a concern.
Heavy metals in water supply, filter adequacy
Activated carbon alone does not remove all heavy metals (e.g., lead, cadmium) without ion-exchange resin or other media. If source water is contaminated, this filter may not reduce metals sufficiently; brand claims should be verified against your local water test.
Stainless steel corrosion and pitting
18/8 stainless steel is highly resistant to corrosion. Pitting from chloride attack is extremely rare in fresh water but could theoretically occur in high-salt environments or if bottle is never rinsed; this is not a documented issue for this product.
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 filtered 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.