Unless noted, specs and performance figures below come from the manufacturers.

The short version

Microplastics are not a chemical dissolved in your water. They are solid particles, and that makes this a size problem. A filter catches a particle when the particle is bigger than the openings it has to pass through. Everything in this guide follows from that one fact.

Here is the honest picture. Whole house systems are built to move a lot of water fast, so their screens and media are relatively coarse. They trim the large end of the microplastic range and let the small end through. The filters that genuinely cover the small end are point of use units at a single tap: certified sub micron filters, and above all reverse osmosis. If microplastics are your concern, the kitchen tap is where the fight is won, and our best whole house water filter guide covers what the big systems are actually for.

What microplastics are, in plain size terms

The EPA defines microplastics as plastic particles ranging from 5 millimeters down to 1 nanometer. Five millimeters is about the size of a pencil eraser. A nanometer is a billionth of a meter. That is an enormous range for one word to cover, and it is why simple claims about removing microplastics mean so little without a size attached.

Some microplastics are made small on purpose, like the plastic beads once common in scrubs and toothpaste. Most are secondary, meaning they broke off something bigger: bottles, bags, food wrapping, car tires, and synthetic clothing all shed particles as they wear down. The smallest pieces, under 1 micron, are called nanoplastics.

To make microns useful, here is the scale. A micron is one step on the same scale: a human hair is about 80 microns wide. A 5 micron filter opening is roughly one sixteenth the width of that hair. It will catch fine sand and silt. It will not catch anything in the bottom half of the microplastic range, because those particles are smaller than its openings, the same way a fishing net with hand sized holes cannot catch minnows.

What the EPA says, and what it has not done

There is no federal drinking water limit for microplastics, and your utility does not test for them or report them. In April 2026, the EPA added microplastics to its draft Contaminant Candidate List for the first time, as a priority group. That list is the starting line of the regulatory process, not the finish. It directs research, monitoring, and data collection so the agency can decide later whether a limit is warranted.

The EPA is candid that the homework is unfinished. Its own summary of the listing notes there are data gaps that require further research before the health risks of microplastics in drinking water are fully understood. Particles have been found in food, beverages, and human tissue, which is a fair reason to care. It is not yet a measured dose and response story like lead. Our view: reducing what you can at the tap is reasonable and cheap. Panic is not supported by the evidence, and no filter purchase should be sold to you on fear.

Your annual water quality report will not mention microplastics. It will tell you plenty else about your water, and our water tool explains how to read it.

The certification picture

There is no standalone NSF standard called microplastics. The claim lives inside NSF/ANSI 401, the standard for emerging compounds and incidental contaminants, the same standard that covers trace pharmaceuticals and similar compounds. Certifiers test the claim using tiny plastic particles, and products that pass earn a microplastics reduction claim in their listing.

Look at where that claim actually shows up in the NSF listings: refrigerator filters, small plumbed in drinking water units, and under sink systems. Point of use products, one and all. A concrete example: Aquasana's Claryum under sink systems are certified to NSF/ANSI 42, 53, and 401, with a certified microplastics reduction of 99.6 percent, built on sub micron filtration. That is what a verified microplastics claim looks like.

Now the contrast that matters for this site. None of the three whole house systems we cover, the Aquasana Rhino, the SpringWell CF1, and the iSpring WGB32B, carries a microplastics certification or claim of any kind. If a whole house product page tells you it removes microplastics, ask for the listing. Pore size logic is not a certification.

What each kind of filter actually catches

Sediment filtration catches the big end only

A sediment filter is a screen, and a screen stops what is larger than its holes. The SpringWell CF1 and the iSpring WGB32B both start with a 5 micron sediment filter. Aquasana rates the Rhino pre filter for particles over 1 micron. Those numbers are respectable for sediment duty: they catch fine sand, silt, and rust, and they protect the rest of the system. Against microplastics, they cover only the top of the range, particles from 5 microns, or 1 micron on the Rhino, up to eraser size. Everything smaller passes through with the water. Our sediment filter guide covers these ratings in full.

Carbon is built for chemicals, not for sized particles

Carbon earns its place in these systems by pulling chlorine and chemicals out of water as it flows past. It does trap some particles along the way, but whole house carbon is chosen for chemistry, not rated as a particle barrier. Tellingly, iSpring publishes a 5 micron rating for the WGB32B sediment cartridge and no particle rating at all for its carbon blocks. Treat any carbon stage in a whole house system as a bonus for the larger particles, not a microplastics solution.

Certified point of use filters cover the small end

Under sink systems like the Aquasana Claryum pair carbon with sub micron filtration, meaning a final barrier with openings under 1 micron, and back it with the NSF/ANSI 401 microplastics claim described above. This is the tier where particle claims get tested rather than asserted. The limitation is reach: one faucet, usually the kitchen, gets this water.

Reverse osmosis is the most thorough option

Reverse osmosis pushes water through a membrane with openings so small that particles cannot fit through them at all. iSpring rates the membrane in its RCC7AK under sink system at 0.0001 micron, and that system is certified to NSF/ANSI 58, the reverse osmosis standard. A 0.0001 micron opening is ten thousand times finer than a 1 micron particle, so microplastics and even nanoplastics have no path through. For particle removal, nothing else in a home comes close.

The limits are practical. Reverse osmosis treats one tap. It works slowly, so it fills a small storage tank. It sends a share of its water to the drain. And it makes little sense for showers and laundry, where nobody is drinking the water anyway.

The honest limits of whole house filtration

Whole house systems move 7 to 15 gallons a minute through your main line. Media fine enough to catch sub micron particles would strangle that flow and crush your water pressure. That is why point of entry systems are built around coarse screens and chemical media, and why no amount of money buys a whole house filter that does what a small membrane at one tap does.

There is also a simple budgeting point. Drinking and cooking use a small share of the water a house runs through its pipes. The rest goes to showers, toilets, laundry, and the garden hose. Spending whole house money on a particle problem means treating a lot of water nobody drinks, with a system that cannot fully treat it anyway.

Who it is for

Households that drink tap water daily and want a verified reduction at the tap they drink from. Buyers who already want a whole house system for chlorine and sediment, and are happy to add a point of use filter at the kitchen sink for particles. Anyone willing to check an NSF listing before believing a claim.

Who should skip this

Skip the whole house route if microplastics are your only concern, because the technology cannot finish the job at main line flow rates. Skip it if your actual problem is visible grit and sand, which is a sediment problem with its own fix. And skip it if your concern is a chemical one such as PFAS or lead, which need their own certified answers: see our PFAS filter guide and our lead filter guide.

Bottom line

For microplastics, buy by particle size and by listing, not by headline. A whole house system will catch the largest particles at its sediment stage and handle chlorine and chemicals at every tap, which is a fine job, just a different one. For the water you drink, a point of use filter certified to NSF/ANSI 401 for microplastics, or a reverse osmosis system certified to NSF/ANSI 58, is the verified answer. Start with the roundup of whole house systems for the main line decision, the sediment guide for screen ratings, and our water tool for what your utility actually reports.