What testing can and cannot show today
Microplastics are tiny plastic particles, and nanoplastics are even smaller. The EPA's research program describes a pressing need to develop and standardize methods for collecting, extracting, quantifying and identifying them, and says it is still assessing health effects in experimental models. That means:
- Home test strips and TDS meters do not measure microplastics.
- Utility Water Quality Reports generally do not list microplastics, because there is no federal drinking water standard for them.
- Specialized lab methods exist in research settings, but results vary by method and are hard to compare.
Be skeptical of any service that offers a quick microplastics count of your tap water.
What a filter certification can tell you
Since you cannot easily measure microplastics in your own water, the useful question is what a filter has been independently tested to reduce. Some certifiers list microplastics reduction claims for drinking water treatment units, tested with particles of a defined size range. To check:
- Find the full model number.
- Look it up in the certifier's listing, such as the NSF database for drinking water treatment units.
- Confirm microplastics, or a fine-particle class, appears as a certified claim.
- Note the rated capacity and replacement interval.
Filter types and particle size
| Type | How it relates to small particles |
|---|---|
| Reverse osmosis | Membrane pores far smaller than typical microplastic particles; certified models list specific claims |
| Fine carbon block | Some are rated for very small particles; depends on the model |
| Sediment cartridge | Catches larger particles; rated in microns |
| Pitcher filters | Varies widely; check the listing |
See carbon vs reverse osmosis.
Practical choices while the science develops
- If drinking and cooking water is your concern, a point-of-use system such as under-sink alkaline RO is the common approach. Check the model's listing for any microplastics claim; Living Waters does not claim one without it.
- Keep filters on schedule; a loaded cartridge is not performing as tested.
- Consider other sources of plastic contact in your kitchen, such as storing water in plastic bottles in heat.
Where Jorge can help
Jorge's free in-home test measures everyday parameters like hardness, dissolved solids and chlorine or chloramine, which shape what system makes sense. He will not claim to measure microplastics at your sink, and he will show you how to read a certification listing for any system you consider.
Questions to ask a filter seller
- Which exact model is certified for microplastics, and by whom?
- What particle size range does the claim cover?
- What is the rated capacity before replacement?
- Are replacement cartridges the same listed model?
- Is the claim on the whole system or only one cartridge?
If the seller cannot point to a listing, treat the claim as marketing.
https://www.epa.gov/water-research/microplastics-research
https://info.nsf.org/Certified/DWTU/
https://www.cdc.gov/drinking-water/prevention/about-choosing-home-water-filters.html
Updated 2026-10-17 · Living Waters · Jorge Canela, Water Quality Specialist