A reverse osmosis (RO) filter is generally the best household option for reducing microplastics because its membrane forms a very fine physical barrier. Ultrafiltration and sufficiently fine microfiltration can also work, but choose an exact model with independent evidence for the particle sizes and reduction rate claimed.
Suitable filter technologies
- Reverse osmosis: Provides a fine membrane barrier, but performance depends on the complete system, testing and maintenance.
- Ultrafiltration: Can physically retain many microplastic particles when the verified filter pore size is suitable.
- Microfiltration: Fine membranes or ceramic elements may reduce larger microplastics. Coarser products may allow smaller particles through.
Activated carbon is better suited to chlorine taste and odour and should not be assumed to remove microplastics unless it includes a suitably rated physical barrier with supporting test results. Similarly, a coarse sediment cartridge may catch larger fragments without retaining smaller ones.
Evidence of microplastic reduction does not establish nanoplastic removal. Nanoplastics are smaller and require a separate, specifically tested performance claim.
Different claims matter: a model tested for microplastics may still need separate evidence for PFAS reduction.
What to check before buying
Check the micron or pore rating and independent results for the exact model, not just the filtration technology or brand.
A smaller micron rating generally indicates a finer barrier, but the number alone does not prove performance. Construction, operating conditions and measured retention efficiency also matter. “Nominal” and “absolute” ratings are not used consistently across manufacturers, so check the stated capture percentage and test method.
Look for:
- an explicit microplastic or relevant fine-particle reduction claim;
- the tested particle-size range and reduction percentage;
- testing or certification by an accredited independent body;
- confirmation that the exact model appears in the certifier’s current public directory; and
- the operating and cartridge-replacement conditions applying to the claim.
Certification scope can change. Verify current claims directly with the relevant certification body rather than relying on packaging, retailer descriptions or brand-wide statements.
Contact our licensed plumbers through the Sydney water filter team to match a verified system to the particle sizes of concern, available pressure, flow and maintenance requirements.