Sub-Zero · Refrigerator Filters
Mist Refrigerator Water Filter Replacement Cartridge 4204490
Lower-concern choice; standard carbon/resin filter with no public PFAS issues, but Sub-Zero offers no transparency.
Sub-Zero's Mist refrigerator filter uses typical activated carbon and ion-exchange resin media, which are not inherent PFAS sources. No lab detections or recalls are publicly documented for this model.
Shop Sub-Zero on Amazon →Material
activated carbon and ion-exchange resin (standard water filter media)
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.
Safe base material
Made from a material with no inherent PFAS use (ceramic, mineral, or natural fiber).
The full breakdown
What it's made of and why it matters
The Mist 4204490 uses activated carbon and ion-exchange resin, the industry standard for refrigerator water filtration. Activated carbon removes chlorine, odor, and some organic compounds through adsorption, while ion-exchange resin softens water by trapping calcium and magnesium ions. These materials are inert when functioning normally and do not leach harmful compounds into drinking water under standard refrigerator conditions (no heating, low pressure, room temperature).
The brand's record and disclosure
Sub-Zero is a premium appliance manufacturer with a clean safety record for water filtration products and no documented recalls specific to this cartridge. However, Sub-Zero has not publicly disclosed testing for PFAS in replacement filters or provided third-party certification of contaminant removal rates. The company relies on standard certification claims but offers minimal transparency compared to some competitors who publish independent NSF test results.
How it compares in its category
Refrigerator filter cartridges like this one are low-risk compared to pitcher filters or faucet-mounted alternatives because they operate under controlled conditions and are replaced frequently (typically every 6-12 months). Sub-Zero's design is proprietary and fits only their models, reducing cross-contamination risk from poor-fit installation. Comparable premium filters from LG, Samsung, and GE use similar carbon-resin technology with equivalent safety profiles; Sub-Zero's main distinction is brand integration rather than superior safety.
If you buy it
Replace the cartridge on schedule (check your fridge's indicator light or every 6 months if dispensing water daily) to prevent bacterial biofilm growth in stagnant filters. Run water through the new filter for 3-5 minutes before drinking to flush carbon dust. Store unused cartridges in a cool, dry place away from direct sunlight. Do not attempt to clean or reuse a cartridge; replacement is the only safe maintenance step.
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.”
Bacterial growth and biofilm in filter media
Activated carbon and ion-exchange resin can harbor bacteria if cartridges are not replaced on schedule or if the refrigerator is infrequently used. This is a maintenance issue rather than a manufacturing defect; regular replacement eliminates this risk.
Carbon dust inhalation or ingestion
New activated carbon cartridges may shed fine black particles initially. Running water through the filter before use washes away this loose material; failure to flush increases risk of carbon particles in drinking water, though this is primarily an aesthetic concern in food-grade activated carbon.
Cartridge housing leachables
Sub-Zero cartridges use food-grade plastic housings meeting FDA standards. No reports of leaching from the casing material itself exist in public records, and the design minimizes water contact with non-carbon media.
Contaminant breakthrough at end of cartridge life
If a filter is used beyond its recommended replacement interval (typically 6 months or 300-500 gallons), activated carbon becomes saturated and loses effectiveness, allowing chlorine and some organic contaminants to pass through. This is a performance failure, not a toxicity hazard, but places reliance on user adherence to replacement schedules.
Ion-exchange resin exhaustion and sodium leaching
Ion-exchange resin in this filter is designed to soften water by exchanging calcium for sodium. Under normal use and replacement intervals, sodium release is negligible. No documented cases of elevated sodium levels from refrigerator filters exist; risk is theoretical only and applies primarily to whole-house systems with infrequent regeneration.
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.
Safer alternatives in Refrigerator Filters
Kenmore
9690 Refrigerator Water Filter 1-Pack, Nsf/wqa/iapmo Certified, Reduces 99% Chlorine & Odor, BPA-Free, Replacement for 46-9690 469690 Lt700p
activated carbon filter cartridge
Lower-concern water filter; carbon-based design unlikely to contain PFAS, but Kenmore makes no explicit PFAS disclosure.
✓Verified PFAS-free by a third party
Kenmore
Pureline Filter Compatible with Whirlpool Everydrop Filter 1
Activated carbon and fiberglass filter media
Lower concern for PFAS; standard cartridge filter with no known PFAS-bearing materials, but brand offers no transparency.
✓Bare metal or glass, no coating at all
Clearly Filtered
Water Pitcher Replacement Filter 3-Pack
Activated carbon and ion-exchange resin filter media
Lower-concern option; activated carbon filters are standard PFAS-reduction media, but verify pitcher durability and actual tested removal rates independently.
✓Brand claims PFAS-free (unverified)
More refrigerator filters 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.