Does a Brita or carbon pitcher remove mercury?

Only if that specific pitcher is certified for mercury under NSF/ANSI 53. The good news is that several carbon pitchers in our catalog, including the Brita Elite, Brita Standard, PUR Plus, and ZeroWater pitchers, are listed on the public NSF/WQA certification database as certified to NSF/ANSI 53 for mercury reduction, so they earn credit in our scoring. A plain carbon pitcher certified only under NSF/ANSI 42 for taste and odor does not - so do not assume mercury reduction from a general carbon claim. The reliable move is to check the model's certification listing for mercury by name.

Does boiling water remove mercury?

No, and it can make things slightly worse: as EPA and CDC guidance on chemical contaminants notes, boiling does not remove dissolved mercury and can concentrate it as water evaporates. Reducing mercury relies on certified treatment instead, such as reverse osmosis under NSF/ANSI 58 or an activated-carbon filter certified for mercury under NSF/ANSI 53.

Contaminant · Water

Mercury

EPA MCL 0.002 mg/L (2 ppb). 9 of the water filters we score hold an accredited NSF, WQA, or IAPMO certification to reduce Mercury, and 6 more market it with no accredited certification we could verify. A claim is not a certification.

What it is

Mercury is a naturally occurring heavy metal, and the practical thing to know is where it comes from: it can dissolve into groundwater and surface water from natural mineral deposits, discharge from refineries and factories, and runoff from landfills and croplands. Because it carries no taste, color, or smell, you will not notice mercury in tap water yourself - laboratory testing is the only way to find it.

Why it matters

The EPA sets a federal maximum contaminant level (MCL, the legal limit for treated water) for mercury of 0.002 mg/L, which is 2 parts per billion. Read that number for what it is: a reference point for how much is allowed in the water leaving the utility, not a description of how any individual filter performs. What we score is whether a filter is certified to reduce mercury, not any health outcome.

What removes it

There are two certified ways to reduce mercury: under NSF/ANSI 58 for reverse osmosis systems, and under NSF/ANSI 53 for select activated-carbon filters whose media is specially formulated to bind it. Here is the trap to sidestep: ordinary carbon filtration certified only under NSF/ANSI 42 is built for taste and odor and is not certified for mercury. So a pitcher or cartridge earns credit here only when it carries an NSF/ANSI 53 or 58 certification that names mercury specifically - a general carbon claim is not enough.

Reference: EPA National Primary Drinking Water Regulations, mercury MCL 0.002 mg/L; NSF/ANSI 53 (drinking water treatment units, health effects) and NSF/ANSI 58 (reverse osmosis).

Scored filters certified for Mercury

8.4
Brita Elite Pitcher (10-Cup)
A pour-through pitcher whose Elite filter is certified to reduce lead, mercury, cadmium and more, with a long 120-gallon cartridge.
7.5
Culligan US-EZ-4 Under-Sink
An under-sink filter genuinely IAPMO certified to NSF/ANSI 42, 53 and 401 for lead, cysts, VOCs, mercury and PFOA/PFOS.
7.2
Aquasana AQ-5200 Under-Sink
Certified for lead and PFAS, cheap per gallon, marketing matches the certified scope.
6.6
Waterdrop G3P800 Tankless RO
A tankless 800 GPD reverse-osmosis system IAPMO-certified to NSF/ANSI 42, 53, 58 and 372 for a broad contaminant list including lead, PFAS, arsenic, nitrate and fluoride.
6.4
PUR Plus Faucet Mount (PFM400H)
A faucet-mount system whose RF-9999 cartridge is genuinely NSF certified for lead, chlorine, mercury and microplastic reduction.
5.9
PUR Plus Pitcher (7-Cup)
An affordable pitcher certified to reduce lead, mercury, microplastics and chlorine, though its 40-gallon filter needs frequent swaps.
5.6
Brita Standard Pitcher
An everyday ion-exchange pitcher certified for chlorine, copper, cadmium and mercury - but notably NOT certified for lead.
4.9
ZeroWater 5-Stage Pitcher (7-Cup)
A five-stage ion-exchange pitcher certified for lead, chromium-6 and PFOA/PFOS - but a short 15-gallon filter makes it costly to run.
4.1
Epic Smart Shield Under-Sink
A slim inline under-sink filter genuinely certified by IAPMO to NSF/ANSI 42, 53 and 401 for lead, VOCs and more - though its PFAS reduction is tested to standards, not in the certified scope.

Marketed for Mercury, but not certified

These scored filters market Mercury reduction but we found no accredited NSF, WQA, or IAPMO certification for it - "tested to" is not "certified to." Absence of certification is not proof a product fails to reduce it, only that we found no independent verification.

6.8
Frizzlife SK99 Under-Sink Filter
A direct-connect 3-stage under-sink filter with a 0.5 micron carbon block, IAPMO certified to NSF/ANSI 42 and 53 for chlorine, lead, VOCs and particulate. Its broader claims (chloramine, PFAS, fluoride) are marketed but not certified.
4.9
Express Water RO5DX 5-Stage RO
A 5-stage under-sink RO whose contaminant figures come from third-party lab testing (QFT Laboratory) to NSF/ANSI methods; we found no accredited NSF, WQA or IAPMO certification listing for this model.
2.7
LifeStraw Home Pitcher
A membrane-and-carbon pitcher marketed against bacteria, microplastics, lead and PFAS, but its claims rest on 'tested to' lab data rather than active third-party certification.
2.5
Clearly Filtered Pitcher
Certified only to NSF/ANSI 42 and 372, its 365+ contaminant claims come from non-accredited lab testing, not health-effects certification.
1.7
Clearly Filtered 3-Stage Under-Sink
A three-stage under-sink system the brand says targets 232+ contaminants, but its performance is lab-tested to NSF protocols rather than third-party certified.
1.5
Great Value Water Filter Pitcher (HS528N)
A budget store-brand pitcher whose Walmart listing says 'Certified to NSF/ANSI 42&53' but names no certifier, number, or registry - an unverifiable claim that earns no certified credit here. No standalone filter price is published, so cost per gallon also can't be computed.

FAQ

Does a Brita or carbon pitcher remove mercury?: Only if that specific pitcher is certified for mercury under NSF/ANSI 53. The good news is that several carbon pitchers in our catalog, including the Brita Elite, Brita Standard, PUR Plus, and ZeroWater pitchers, are listed on the public NSF/WQA certification database as certified to NSF/ANSI 53 for mercury reduction, so they earn credit in our scoring. A plain carbon pitcher certified only under NSF/ANSI 42 for taste and odor does not - so do not assume mercury reduction from a general carbon claim. The reliable move is to check the model's certification listing for mercury by name.
Does boiling water remove mercury?: No, and it can make things slightly worse: as EPA and CDC guidance on chemical contaminants notes, boiling does not remove dissolved mercury and can concentrate it as water evaporates. Reducing mercury relies on certified treatment instead, such as reverse osmosis under NSF/ANSI 58 or an activated-carbon filter certified for mercury under NSF/ANSI 53.