NSF/ANSI 42 vs 53 vs 401: which one actually removes lead?

Last reviewed July 2026.

Short answer: 53. If you are buying a water filter because you are worried about lead, the only number that matters is NSF/ANSI 53. A filter certified to NSF/ANSI 42 — and only 42 — is a genuinely certified filter that makes no certified lead claim whatsoever. It is certified to improve the taste.

This is not a technicality. Brita's Standard filter (model OB03), the most widely sold pitcher filter in America, is certified to NSF/ANSI 42 only. Berkey's NSF listing covers NSF/ANSI 42 only. Both are honestly, accurately described as certified. Neither carries a certified lead claim.

The three numbers

And watch for NSF/ANSI 372 — it is not a filtration standard

You will see filters advertised as "NSF 42 and 372 certified." Two numbers, both real, and the impression is of thorough coverage. It isn't.

NSF/ANSI 372 certifies that the product's materials are lead-free — that the plastic and fittings don't leach lead into your water (no more than 0.25% weighted average lead content). It says nothing whatsoever about the filter removing lead that is already in your water. It is a materials standard, not a performance one.

So "42 and 372" means: improves taste, and the housing won't poison you. It does not mean the filter takes lead out. Only NSF/ANSI 53 does that. Waterdrop's everydrop-compatible WD-F38 is sold exactly this way — 42 and 372, no 53 — while the everydrop filter it replaces holds 42, 53 and 401. Because we rank on certified filtration, we exclude 372 from the standards column entirely: it isn't filtration.

Certification is per model, not per brand

The single most expensive mistake buyers make is assuming a certification travels across a brand's product line. It does not. Brita's Elite filter (OB06) holds 42, 53 and 401. Brita's Standard filter (OB03) holds 42. Same brand, same pitcher, same shelf — completely different claims. LG's LT1000P is listed to 42, 53 and 401; its LT800P is listed to 42 and 53, with no 401.

So "is Brita certified?" is not an answerable question. "Is the OB03 certified for lead?" is — and the answer is no.

And the cheap one is often not cheap

Because a filter's certification includes a rated capacity — the number of gallons the claim is good for — you can divide price by that capacity and get the honest cost of the filtration. Do that to Brita's two pitcher filters and the result inverts the shelf price:

The filter that costs 2.5× more at the register is 17% cheaper per gallon — and it is the only one of the two that filters lead. The $7.99 sticker is doing a lot of work.

Who certifies, and why three names appear

NSF/ANSI standards are the standards. Three accredited bodies certify against them: NSF International, the WQA (Water Quality Association) and IAPMO R&T. All three are legitimate and all three publish public listings. A filter certified by WQA to NSF/ANSI 53 is certified to NSF/ANSI 53 — it just won't appear in NSF's database, which is why Brita's pitcher filters (WQA) and ZeroWater (IAPMO) can't be found there and are sometimes wrongly called uncertified.

"Tested to" is not "certified to"

Watch for the phrase "tested to NSF/ANSI 53 standards". That means a lab ran the protocol — once, on a sample the brand chose. Certified means an accredited body controls the testing, audits the factory on an ongoing basis, and lists the product publicly where anyone can look it up. Clearly Filtered and Epic both publish independent lab results and neither appears in the NSF certified listings. That is not proof of a bad filter; it is the absence of a public record to hold it to.

See every filter we track, ranked by cost per certified gallon, with its standards →

We do not test filters — we index what accredited certifiers publish, with attribution, and make no health or treatment claims. We are not affiliated with NSF International.