Soma · Filtered Water Bottles
Soma 24oz Stainless Steel Water Bottle
Lower concern for the bottle itself; verify cap materials with brand before buying.
Soma's stainless steel water bottle uses a PFAS-lower-concern primary material. However, the brand makes no public disclosure about PFAS in the bottle or its closures/seals. Stainless steel rarely contains PFAS, but plastic or rubber caps and gaskets, not disclosed here, may pose risk if treated for water resistance.
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Stainless steel bottle (primary); internal cap/closure materials unspecified
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 Soma 24oz bottle is constructed from stainless steel, a non-reactive metal that does not leach heavy metals, BPA, or other endocrine disruptors into water over time. Stainless steel is one of the safest food-contact materials available because it forms a passive oxide layer that resists corrosion and leaching even with acidic beverages. The primary unknown is the composition and treatment of internal cap seals and closure gaskets, which are not detailed in public product specifications and could potentially contain elastomers with trace off-gassing potential.
The brand's record and disclosure
Soma is owned by The Coca-Cola Company and markets itself as a filtered water bottle brand focused on sustainability and reducing single-use plastic. The brand has not published detailed safety data sheets, material certifications (such as NSF, FDA, or third-party testing), or formal statements addressing chemical safety beyond PFAS. No significant safety recalls or controversies appear in public records for this specific product. Transparency on cap material sourcing and manufacturing testing is notably absent from consumer-facing communications.
How it compares in its category
Filtered water bottles typically combine metal or plastic housing with replaceable cartridge filters and plastic or rubber caps. Soma's stainless steel construction places it in the lower-risk tier compared to plastic alternatives (which may contain BPA or degradation byproducts), but it does not stand out for transparency or third-party certification. Competitors like Hydro Flask and S'well also use stainless steel but similarly do not publish comprehensive safety data. The internal filter and cap materials are the variable across this category; Soma's lack of disclosure is standard rather than exceptional.
If you buy it
Use only cold to lukewarm water in stainless steel bottles to avoid any risk of coating or seal degradation under heat stress; do not fill with hot beverages or run through dishwashers unless the manufacturer explicitly confirms the cap is rated for that. Replace the filter cartridge on the manufacturer's recommended schedule (typically every 2-3 months or per usage) to prevent bacterial colonization in the filter media, which becomes a contamination risk if filters are left unchanged. Rinse the bottle interior and cap thoroughly weekly and allow to air-dry completely, particularly the cap threads and seals, to prevent mold or bacterial growth in damp crevices. Contact Soma directly before purchase if you need written confirmation that all internal materials, including cap gaskets, are free of specific hazards (BPA, phthalates, or 1,4-dioxane).
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/closure material composition (unspecified)
Soma does not publicly disclose the elastomer or plastic composition of internal cap seals and gaskets. Elastomers in caps can shed trace amounts of volatile compounds or plasticizers if not food-grade; without material confirmation from the brand, low-level off-gassing cannot be ruled out.
Bacterial growth in filter cartridge and internal seals
Filtered water bottle cartridges are known vectors for bacterial colonization if not replaced on schedule or if the bottle is stored wet. Soma does not provide detailed maintenance or replacement intervals in most product documentation, increasing the risk of user error.
Stainless steel coating or interior finish degradation
Food-grade stainless steel (typically 304 or 316 grade) does not leach heavy metals under normal use conditions. However, damage to the interior surface from aggressive cleaning, acidic contents, or manufacturing defects could theoretically expose base metal; no defects are documented for this product.
Volatile organic compounds (VOCs) from plastic filter housing or cap
The filter cartridge housing and cap elements often contain plastic resins that may off-gas low levels of VOCs, particularly if exposed to warm water or left unused for extended periods. Soma does not provide VOC emissions testing or material safety certifications.
Microplastics from filter cartridge wear or degradation
Activated carbon and polymer filter media can shed microfibers or carbon particles if over-used or damaged. Soma's public documentation does not address filter durability testing or particle shedding specifications.
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.