Sub-Zero · Refrigerator Filters
Sub-Zero Refrigerator 4204490
Lower-concern choice; standard carbon filters rarely use PFAS, but Sub-Zero doesn't disclose.
Sub-Zero's replacement water filters (model 4204490) use conventional activated carbon or mechanical media, which are not typically manufactured with PFAS. However, Sub-Zero makes no public PFAS disclosure or third-party certification for this product.
Shop Sub-Zero on Amazon →Material
Activated carbon/mechanical filtration cartridge (standard RO or carbon 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 Sub-Zero 4204490 is a replacement water filter cartridge using activated carbon and mechanical particulate media, the industry standard for refrigerator and under-sink filtration. Activated carbon works by adsorption, trapping chlorine, odor, and some organic contaminants on its porous surface without releasing chemical byproducts into water. The mechanical stage removes sediment and particles. This chemistry is inherently low-risk compared to ion-exchange or membrane systems, with no known leaching concerns under normal residential water pressure and temperature.
The brand's record and disclosure
Sub-Zero is a premium appliance manufacturer with no publicly documented recalls or safety violations tied to water filters. The company does not proactively disclose detailed material sourcing or third-party certification (NSF, WQA) for this specific cartridge model in readily available consumer-facing documents, which is typical for OEM filters. The filter is not registered with NSF International or WQA on publicly searchable databases, so independent verification of contaminant reduction claims is limited to manufacturer specifications.
How it compares in its category
OEM refrigerator filters like this one are chemically comparable to third-party carbon filters (Whirlpool, GE, generic aftermarket brands) and use the same activated carbon media. The main difference is cost and warranty integration with the appliance. Aftermarket alternatives may carry NSF certification, offering independent verification; Sub-Zero does not advertise this for the 4204490. Performance and safety profiles are functionally equivalent across the category.
If you buy it
Replace the cartridge every 6 months or after 300 gallons (per manufacturer guidance), whichever comes first, to prevent bacterial colonization in saturated carbon and maintain flow rate. Store unused filters in a cool, dry place away from direct sunlight. Do not attempt to regenerate or clean the cartridge; it is single-use. Monitor filter pressure gauges if your model has one, or note reduced water flow as a replacement trigger. Flush the system for 5 minutes after installation to clear loose 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.”
Bacterial growth if maintenance neglected
Activated carbon filters can support bacterial biofilm growth if not replaced on schedule, particularly in warm environments or low-water-use periods. This is a maintenance issue, not an inherent material hazard, and is prevented by timely replacement.
Carbon dust ingestion after installation
Unfiltered carbon particles can shed into water immediately after new cartridge installation. Flushing the system for several minutes before use prevents this; no toxicity risk from the carbon itself, only a sediment nuisance.
Housing or seal material leachables
Sub-Zero does not publicly disclose the polymer or elastomer composition of the cartridge housing and seals. No recalls or complaints are on record. Activation carbon cartridge housings are typically food-grade polypropylene or similar, with no established leaching under standard refrigerator temperatures and pressures.
Chlorine byproduct accumulation
Activated carbon does not chemically transform chlorine into harmful disinfection byproducts; it physically removes chlorine before such reactions occur. No known risk of DBP generation from this filter type.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 70% 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.