Under-sink filter · checked 16 Oct 2026
Culligan EZ-Change Under Sink Drinking Water Filtration System
Model US-EZ-4 · replacement filter RC-EZ-4
Each claim, checked
What the brand says, what a certification listing shows for this model, and where each fact comes from. We read listings; we do not test products.
- Certified (listing checked)The certifier’s public listing shows this claim for this model.
- Brand says certifiedThe brand says certified; IAPMO’s listing does not show it. NSF can be checked by hand.
- Brand claim onlyThe brand claims it without citing a certification.
| Contaminant | Brand claim | Standard | Certifier | Confirmed? | Source, date checked |
|---|---|---|---|---|---|
| Lead | “CERTIFIED BY IAPMO: NSF/ANSI 42 for chlorine taste and odor, chloramines, and particulate Class 1; NSF/ANSI 53 for lead, cysts, mercury, VOC, MTBE, and turbidity.” brand source | NSF/ANSI 53 | IAPMOfile W-9334 | Certified — IAPMO listing, checked 16 Oct 2026 | IAPMO listingchecked 16 Oct 2026 |
| PFOA | not claimed on the brand pages we read | NSF/ANSI 53 | IAPMOfile W-9334 | Certified — IAPMO listing, checked 16 Oct 2026 | IAPMO listingchecked 16 Oct 2026 |
| PFOS | not claimed on the brand pages we read | NSF/ANSI 53 | IAPMOfile W-9334 | Certified — IAPMO listing, checked 16 Oct 2026 | IAPMO listingchecked 16 Oct 2026 |
| Chlorine | Same statement as for Lead. brand source | NSF/ANSI 42 | IAPMOfile W-9332 | Certified — IAPMO listing, checked 16 Oct 2026 | IAPMO listingchecked 16 Oct 2026 |
| Chloramine | Same statement as for Lead. brand source | NSF/ANSI 42 | IAPMOfile W-9332 | Certified — IAPMO listing, checked 16 Oct 2026 | IAPMO listingchecked 16 Oct 2026 |
| Particulates | Same statement as for Lead. brand source | NSF/ANSI 42 | IAPMOfile W-9332 | Certified — IAPMO listing, checked 16 Oct 2026 | IAPMO listingchecked 16 Oct 2026 |
| Cysts (Giardia, Cryptosporidium) | Same statement as for Lead. brand source | NSF/ANSI 53 | IAPMOfile W-9334 | Certified — IAPMO listing, checked 16 Oct 2026 | IAPMO listingchecked 16 Oct 2026 |
| Mercury | Same statement as for Lead. brand source | NSF/ANSI 53 | IAPMOfile W-9334 | Certified — IAPMO listing, checked 16 Oct 2026 | IAPMO listingchecked 16 Oct 2026 |
| VOCs (volatile organic chemicals) | Same statement as for Lead. brand source | NSF/ANSI 53 | IAPMOfile W-9334 | Certified — IAPMO listing, checked 16 Oct 2026 | IAPMO listingchecked 16 Oct 2026 |
| Turbidity | Same statement as for Lead. brand source | NSF/ANSI 53 | IAPMOfile W-9334 | Certified — IAPMO listing, checked 16 Oct 2026 | IAPMO listingchecked 16 Oct 2026 |
| Microplastics | not claimed on the brand pages we read | NSF/ANSI 401 | IAPMOfile W-12300 | Certified — IAPMO listing, checked 16 Oct 2026 | IAPMO listingchecked 16 Oct 2026 |
| BPA, nonylphenol and similar | not claimed on the brand pages we read | NSF/ANSI 401 | IAPMOfile W-12300 | Certified — IAPMO listing, checked 16 Oct 2026 | IAPMO listingchecked 16 Oct 2026 |
| Pharmaceuticals | not claimed on the brand pages we read | NSF/ANSI 401 | IAPMOfile W-12300 | Certified — IAPMO listing, checked 16 Oct 2026 | IAPMO listingchecked 16 Oct 2026 |
| Taste and odor | not claimed on the brand pages we read | NSF/ANSI 42 | IAPMOfile W-9332 | Certified — IAPMO listing, checked 16 Oct 2026 | IAPMO listingchecked 16 Oct 2026 |
Filter changes, by the brand’s numbers
How often Culligan says to replace each part. Real filter life depends on how much water you use and what is in it.
| Part | Brand says replace every | Changes a year | Source, date checked |
|---|---|---|---|
| RC-EZ-4 EZ-Change replacement cartridge | 6 months or 500 gallons“Filter Life: 500 gallons or 6 months” | 2 | brand sourcechecked 16 Oct 2026 |
Certification listings found
IAPMO · NSF/ANSI 372 · file WP-11101
CULLIGAN INTERNATIONAL lists US-EZ-4
Materials only (no reduction claim)
Open the listing · checked 16 Oct 2026
IAPMO · NSF/ANSI 401 · file W-12300
CULLIGAN INTERNATIONAL lists US-EZ-4
Bisphenol A · Estrone · Ibuprofen · Naproxen · Nonyl phenol · Phenytoin · Microplastics
Open the listing · checked 16 Oct 2026
IAPMO · NSF/ANSI 401 · file WP-11635
CULLIGAN INTERNATIONAL lists IC-EZ-4, US-EZ-4
Bisphenol A · Estrone · Ibuprofen · Naproxen · Nonyl phenol · Phenytoin Microplastics
Open the listing · checked 16 Oct 2026
IAPMO · NSF/ANSI 42 · file W-9332
CULLIGAN INTERNATIONAL lists US-EZ-4
Chlorine Taste and Odor · Chloramine · Particulate Class I
Open the listing · checked 16 Oct 2026
IAPMO · NSF/ANSI 42 · file WP-10825
CULLIGAN INTERNATIONAL lists IC-EZ-4 1, US-EZ-4 1
Chlorine Taste and Odor · Chloramine · Particulate Class I
Open the listing · checked 16 Oct 2026
IAPMO · NSF/ANSI 53 · file W-9334
CULLIGAN INTERNATIONAL lists US-EZ-4
Cyst · Lead · Mercury · MTBE · PFOA/PFOS · Turbidity · VOC
Open the listing · checked 16 Oct 2026
IAPMO · NSF/ANSI 53 · file WP-10826
CULLIGAN INTERNATIONAL lists IC-EZ-4 1, US-EZ-4 1
Cyst · Lead · Mercury · MTBE · PFOA/PFOS · Turbidity · VOC
Open the listing · checked 16 Oct 2026
IAPMO · NSF/ANSI/CAN 372 · file W-9336
CULLIGAN INTERNATIONAL lists US-EZ-4
Materials only (no reduction claim)
Open the listing · checked 16 Oct 2026
Check it yourself
NSF’s and WQA’s terms don’t allow automated lookups, so these links open their public listings for this model:
- NSF listing search: US-EZ-4
- NSF listing search: RC-EZ-4
- NSF listing search: Culligan
- WQA listing search: US-EZ-4
- WQA listing search: RC-EZ-4
- WQA listing search: Culligan
- IAPMO R&T listing directory
What the brand says about certification
- “CERTIFIED BY IAPMO: NSF/ANSI 42 for chlorine taste and odor, chloramines, and particulate Class 1; NSF/ANSI 53 for lead, cysts, mercury, VOC, MTBE, and turbidity.” source checked 16 Oct 2026