Water Filters

The concern: A water filter is the one product on this site where the microplastic question runs in both directions at once. UK tap water carries microplastic particles — far fewer than bottled water, but not zero — and the right filter removes the large majority of them. The filter itself, though, is almost always a plastic jug or a plastic housing, and your drinking water stands against that plastic before it reaches the glass. Both facts are true simultaneously, and a rating that reported only one of them would be misleading. The second complication is that filtration performance varies enormously between products that look identical on a shelf: two jugs of the same size and price can differ by two orders of magnitude in the particle size they stop.

Why it matters: We rate a filter the way we rate everything else here — on the material in sustained contact with what you drink. A plastic jug body means a plastic drinking surface whatever the cartridge inside it removes, which is why most filter jugs on this page carry a Contains Microplastics badge despite removing microplastics being their entire purpose. That is not a contradiction we are trying to smooth over; it is the honest shape of the category. It also has a practical consequence: filtering your water and then leaving it standing in the plastic jug all day gives back some of what the filter took out. The stainless steel and ceramic systems are the only filters here where the water never rests against a polymer.

What to look for: Treat the badge and the filtration spec as two separate questions, because they are. For the badge, look for a body made of stainless steel, glass or ceramic rather than plastic — gravity systems and steel-sump under-sink housings are where those exist. For filtration, look for a stated pore rating in microns: most microplastics measured in tap water are larger than one micron, so anything rated at one micron or finer catches the large majority of them, while the loose granular carbon used in the cheapest jugs does not. Independent certification beats a marketing claim every time — NSF/ANSI 53 for cyst reduction and NSF/ANSI 401 for microplastic reduction are the two that mean something. Where a manufacturer publishes no pore rating at all, as several of the best-known jug brands do not, treat the absence as the answer.