Sub-Zero · Refrigerator Filters
Sub-Zero Replacement Filter DEC3650RIDR 4204490
Lower PFAS concern for typical carbon filters, but Sub-Zero does not publicly disclose filter composition or PFAS testing.
The DEC3650RIDR is a replacement water filter cartridge using activated carbon, a well-established lower-risk media for filtration that does not inherently require Teflon-family coating coatings. Sub-Zero makes no public claim about PFAS-free status or third-party verification.
Shop Sub-Zero on Amazon →Material
Activated carbon cartridge 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 DEC3650RIDR is a replacement cartridge filter using activated carbon media, the industry standard for refrigerator water filtration. Activated carbon works by adsorption, trapping chlorine, taste, and odor compounds in its porous structure rather than leaching chemicals into water. Sub-Zero does not publicly disclose the exact substrate material (coconut shell vs. coal-based carbon) or binding agents, but activated carbon itself is food-contact-safe and FDA-approved for this application.
The brand's record and disclosure
Sub-Zero maintains a premium brand reputation but does not publicly disclose filter material composition, third-party certifications, or PFAS testing on its website or product documentation. The brand does not list NSF, WQA, or equivalent water filter certifications for this model. No known recalls or contamination incidents are on record for this specific filter cartridge, and Sub-Zero as a brand has no documented water-filter-related safety controversies.
How it compares in its category
Refrigerator filters are lower-risk than pitcher filters because water contact is brief and volumes are small. This cartridge is typical among OEM filters in offering activated carbon without publicly disclosed additives. Most competitors (Whirlpool, LG, Samsung OEM filters) similarly lack third-party certification and material transparency, making Sub-Zero's transparency gap normal rather than unusual in this category.
If you buy it
Replace every 6 months or per manufacturer guidance to prevent bacterial biofilm buildup inside the cartridge housing and maintain filtration efficacy. Do not attempt to clean or reuse; activated carbon is exhausted after use. Store unopened filters in a cool, dry place away from direct sunlight. Flush the filter by running water for 2-3 minutes after installation to remove any residual 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 in housing
If filter is not replaced on schedule, stagnant water and warm refrigerator conditions can allow bacterial biofilm to colonize the cartridge interior and bypass media. Sub-Zero's lack of antimicrobial housing disclosure means no special inhibition is noted.
Carbon dust or fines leaching into water
Poorly manufactured or damaged carbon cartridges can release fine particles into water. Sub-Zero does not disclose quality control standards or testing for particle shedding. Flushing after installation mitigates this.
Housing material leachables
Filter housing is typically food-grade plastic (likely polypropylene), and no established leaching or contamination incidents are on record for Sub-Zero refrigerator filters. Material composition is not publicly detailed.
Heavy metals in activated carbon source
Food-contact activated carbon must meet FDA specifications that limit arsenic, lead, and cadmium. Sub-Zero does not publish carbon source or heavy metal testing, but no contamination reports exist for this model.
Wear or degradation over time
Activated carbon becomes exhausted and loses adsorption capacity after 6 months of typical use. Expired filters continue to pass water but offer diminished chlorine and taste removal. Sub-Zero provides no visual exhaustion indicator on this model.
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.