The question behind the question

People ask which filter type is better. The listings answer a narrower question: which claims exist in which shape.

That turns out to decide most of it.

A form holding four certified lead models is not a form you shop for lead in, whatever else it does well.

The matrix

Fourteen certified-claim rosters, grouped by NSF’s own product category heading, on 10 September 2026.

Claim Pitcher Faucet mount Counter-top Fridge Plumbed-in Under-sink tap Whole house Total
Lead (53) 4 29 24 282 161 113 0 615
Cyst (53) 11 1 9 311 493 118 0 1,104
Microplastics (401) 71 32 18 49 416 88 0 806
Turbidity (53) 11 1 7 54 154 48 0 290
TTHM (53) 1 29 24 18 21 56 4 153
VOC (53) 1 29 24 17 16 55 4 146
PFAS (53) 1 0 19 5 14 33 0 72
Chloramine (42) 0 2 22 16 34 29 0 137
Fluoride (58) 0 0 0 0 0 127 0 127
Cr-6 (58) 0 0 0 0 0 120 0 120
Nitrate (58) 0 0 0 0 0 84 0 84
Arsenic (53/58) 1 0 1 0 0 133 0 135
Radium (44) 0 0 0 0 0 0 114 114

Counts are distinct models. NSF lists a model once per facility and claim, so its own row totals run higher.

The pitcher, honestly

Pitchers are the default purchase and the narrowest certified form.

4 of the 615 lead-certified models are pour-through. 1 of 72 for PFAS. 1 of 153 for trihalomethanes. 1 of 146 for VOC.

The four lead-certified pitchers are the Brita Pacifica, the Brita Tidal, the Electrophor P85A5PbFM and the 4Patriots Patriot Pure.

But under NSF/ANSI 401, pitchers hold 71 of 806 microplastics listings. They also hold 11 cyst and 11 turbidity listings.

So the pitcher is a real certified form. It is just certified mostly for things other than the metal people buy it for.

→ Microplastics: what the NSF/ANSI 401 claim covers

The refrigerator filter, which outperforms its reputation

The surprise in the data.

Refrigerator filters hold 282 of the 615 lead-certified models — 45.9 percent of the entire field. They hold 311 of 1,104 cyst listings.

They are weaker elsewhere: 18 of 153 for trihalomethanes, 17 of 146 for VOC, 5 of 72 for PFAS.

NSF separates integrated cartridges from aftermarket ones, and both are counted here. A listing is per model, so a certified aftermarket cartridge is certified as listed and nothing more.

→ The 615 filters certified for lead

The faucet mount is one company

A finding worth stating carefully, because it is unusual.

Every faucet-mount model certified for lead is also certified for trihalomethanes and for VOC. Not overlapping sets — the identical 29 models.

All 29 come from a single company, Kaz USA, a Helen of Troy company. All 29 also sit inside the 32 faucet-mount models certified for microplastics.

Other companies sell faucet mounts. None currently holds these listed claims.

For three contaminants the form is already decided

Fluoride, nitrate and hexavalent chromium are certified under NSF/ANSI 58 only.

Every one of those models — 127 fluoride, 120 hexavalent chromium, 84 nitrate — is plumbed in to a separate tap.

No pitcher. No faucet mount. No counter-top. No refrigerator filter. No point-of-entry product.

The form follows the technology: these are reverse osmosis claims, and reverse osmosis lives under a sink with its own faucet.

→ Reverse osmosis: what NSF/ANSI 58 actually certifies

Whole house is nearly empty of health claims

Across all fourteen rosters, the point-of-entry column holds three entries.

Four models for trihalomethanes, the same four for VOC, and 114 softeners certified for radium and barium under NSF/ANSI 44.

Lead, PFAS, cyst, fluoride, nitrate, hexavalent chromium, arsenic, turbidity, microplastics and chloramine return no point-of-entry product at all.

Chlorine and taste-and-odour claims under NSF/ANSI 42 are the exception, and they are counted separately.

→ What is actually certified for whole-house treatment

The decision framework

1. Name the claim before the shape

Every row above is a different answer. Choosing the form first eliminates claims you may need.

2. Check whether your claim exists in the form you want

Three contaminants have one form. Several have none at whole-house scale. The matrix tells you before you shop.

3. Where several forms qualify, choose on habit

Lead has six viable forms. At that point cartridge cost, flow rate and whether you will actually replace it matter more than the certification.

→ Once it is fitted: rated life, running cost, and the listed element

4. Verify the specific model, not the brand

Certification is per model and per claim. A brand holding a lead claim on one product says nothing about the next one in the range.

→ How to check a certification claim yourself

5. Remember what point-of-use does not cover

EPA notes a point-of-use device treats only the water consumed. Contaminants absorbed through skin or inhaled in a shower are not addressed by it.

The decision path

What you need reduced Forms that hold the claim Practical answer
Lead Six forms, 615 models Fridge filter or under-sink; pitcher only from 4
Cyst Six forms, 1,104 models Widest choice on the site
Microplastics Six forms, 806 models Pitcher is genuinely competitive here
PFAS Counter-top, under-sink, plumbed-in 1 pitcher, no faucet mount
Trihalomethanes or VOC Six forms plus 4 whole-house Faucet mount is well represented
Fluoride, nitrate or Cr-6 Under-sink separate tap only Reverse osmosis, no alternative form
Radium Whole-house softener or under-sink RO Two routes, opposite architectures
Chloramine Counter-top, plumbed-in, under-sink No pitcher holds it
Anything, whole house Almost nothing certified Reconsider the scope

Choose a pitcher if

  • Microplastics, cyst or turbidity is the claim you want, where pitchers are properly represented.
  • You are renting, cannot plumb anything, and one of the four lead-certified models fits.

Choose a fridge or under-sink filter if

  • Lead is the concern. Between them they hold 395 of the 615 certified models.
  • You want a claim that pitchers barely hold, such as PFAS or chloramine.

Choose under-sink with a separate tap if

  • Fluoride, nitrate or hexavalent chromium is the number on your report. Nothing else is certified.

Choose nothing if

  • Your report shows no exceedance and no claim on the list matches a measured problem in your water.

→ Testing city water: what your utility already measured

Mistakes that cost the most money

Buying a pitcher for lead without checking the model. Four of 615 certified models are pitchers. The odds are against any given one.

Assuming whole-house means more protection. For most health claims there is no certified point-of-entry product to buy.

Trusting the brand rather than the model. Certification is recorded per model, and ranges are rarely certified uniformly.

Choosing the form before the contaminant. For fluoride, nitrate and hexavalent chromium that decision removes every certified option.

Reading absence as failure. A filter without a listed claim is untested against it, not proven useless. It is simply unverifiable.

Forgetting the cartridge. MDH states unmaintained units lose effectiveness, and in some cases can make water quality worse and make you sick.

Three situations, and what changes

Renting a flat, worried about lead. Pitchers and faucet mounts are the only forms you can fit. That is 4 certified pitchers and 29 faucet mounts from one company. A countertop unit adds 24 more. The choice is small but it exists, and it has to be model-specific.

Owning a house, fluoride on the report. The matrix collapses to one row. All 127 certified models are plumbed in to a separate tap, so the decision is reverse osmosis or nothing certified. The remaining questions are drain water, tank space and running cost.

A family that never changes cartridges. The form matters less than the habit. A refrigerator filter with a dashboard reminder gets replaced; a under-sink cartridge in a cupboard often does not. An expired cartridge is the common failure mode across every form here.

The objections worth answering

“Pitchers are fine, everyone uses them.” For microplastics, cyst and turbidity the listings back that up. For lead, PFAS, trihalomethanes and VOC there is almost nothing certified in that shape.

“A fridge filter is just a convenience item.” It holds 45.9 percent of the certified lead field and 311 cyst listings. On certification alone it is the strongest consumer form in this data.

“I would rather treat the whole house.” So would many people. Across fourteen claims the point-of-entry column holds 4 trihalomethane models, the same 4 for VOC, and 114 radium softeners.

“These counts must be out of date.” Every roster here was captured on 10 September 2026 and re-checked against NSF’s own reported totals. Counts change; that is why each claim carries a capture date.

“Certification is just a sticker.” It is the only part of a filter claim anyone can verify without laboratory equipment. Without it there is a box, a brand and a number nobody tested.

Who this is for

Anyone deciding between a pitcher, a faucet mount, a counter-top unit, a refrigerator filter, an under-sink system or whole-house treatment, who wants the choice narrowed by evidence rather than by packaging.

It assumes you already know which contaminant you are treating. If you do not, that comes first.

→ How to read your water quality report

What to settle first

Which claim do I need, and which shapes actually hold it?

The matrix above answers the second. Your report answers the first. In that order the decision is usually short.

→ Which claims exist at all, and how populated each is → How to check a certification claim yourself → Point of use or whole house → The NSF standards, and what each one covers → Reverse osmosis: what NSF/ANSI 58 actually certifies → Nitrate, certified in exactly one product form → What EPA says removes what, before the product form question → Radon, certified on 30 models from two companies → Asbestos: 264 certified models and not one pitcher → Filter First: 28 models, one company, one product form → Where pitchers do well: the NSF/ANSI 401 claims