Under-sink reverse osmosis compared by certification

Of the 24 under-sink and countertop reverse osmosis (RO) systems in our data, 3 have a lead claim and 4 have a PFAS claim backed by an IAPMO R&T listing for that model, checked 16 Oct 2026. Thirteen make a lead claim and ten make a PFAS claim without saying the claim is certified.

How to read the table

Each label describes the brand's lead or PFAS claim, not the system as a whole. A system can hold an RO listing for TDS, or a 372 listing for the lead content of its parts, while its lead or PFAS claim is not backed by any listing.

• Certified (IAPMO listing, checked 16 Oct 2026): an active listing in IAPMO R&T's directory shows the claim for this model or its cartridge.
• Brand says certified, not found in IAPMO's listing; check NSF: the brand says the claim is certified, and IAPMO has no listing that shows it. Some of these brands name NSF or WQA, which we check by hand; you can search NSF's listings and WQA's directory.
• Brand claim, no certification cited: the brand states the reduction without saying it is certified, and IAPMO lists nothing for it.
• No claim: the brand does not claim to reduce it.

The table

What the certified listings show

• Waterdrop G3P600 and G3P800: the NSF/ANSI 58 listing shows lead, along with TDS, fluoride, cadmium, barium and radium, for each system's RO membrane. PFOA and PFOS are on a separate NSF/ANSI 53 listing for WD-G3-CB, rated 1,100 gallons, which the 58 listing calls a carbon filter.
• AquaTru Classic: the NSF/ANSI 58 listing shows lead, arsenic, nitrate and nine more claims for the AT2002 RO filter. The NSF/ANSI 53 listing shows PFOA and PFOS for cartridges AT2003 and AT2004, rated 600 gallons.
• APEC ROTL-A1000: the NSF/ANSI 58 listing shows TDS, PFOA and PFOS for the FI-ROA1000 membrane.

Reading an RO claim

• Look past the number 58. EPA lists NSF/ANSI 58 for reverse osmosis, but each listing names its own contaminants. The three 58 listings above run from 3 claims to 12.
• 372 is not removal. A 372 listing covers the lead content of the parts, not what the system takes out. More in NSF/ANSI 42 vs 53 vs 58 vs 401 vs P473 explained.
• Find the PFAS cartridge. On the Waterdrop G3 and the AquaTru, the PFAS claim sits on a cartridge other than the membrane, and EPA says filters work only if maintained according to the manufacturer's instructions.
• Expect waste water. EPA estimates RO wastes about one gallon of water for every gallon treated.

Why RO suits PFAS, and what a PFAS listing does and does not show, is in our reverse osmosis and PFAS guide.