Filtration
What the Puure® filter reduces, and what it doesn't
Honest answers, backed by an independent lab. The Nano filter was tested by Measurlabs, ISO/IEC 17025 accredited, on over 200 substances. Here is what it does, and what we don't claim.
Updated 23 October 2026
Measured by the lab, on the Nano filter
Figures from Measurlabs reports 25146 and 30494, ISO/IEC 17025 accredited labs. Measured on the Nano filter only.
Lead
99.9% reduced.
PFAS
20 tested, sum reduced by at least 99%.
Microplastics
No particles detected after filtration.
Pesticides
157 tested, 156 below the quantification limit after filtration.
Fluoride
99.9% reduced: 1 mg/L before, not detected after filtration, in a dedicated test.
What we don't claim
Bacteria and viruses
Tap water in the UK and Europe is disinfected before it reaches you. The Puure® filter is not a microbiological filter, and we don't present it as one.
Nitrates, hormones, medicines
Not in the results we publish today. We don't claim them.
Softening
The filter is not a water softener: calcium and magnesium stay in the water. The limescale stage reduces limescale in the kettle, tea and coffee. Hard water and limescale
TDS
A TDS meter counts dissolved minerals. The filter keeps the minerals, so the reading barely moves. That is by design: it is not reverse osmosis.
What about the filter itself?
Is there plastic inside?
The housing is stainless steel. The filter inside has a shell, like every filter. Its materials are Tested and Certified by NSF International against NSF/ANSI 42, for material requirements only. After filtration, the lab detected no microplastic particles.
Advanced or Nano?
The results above are for Nano. Advanced is our everyday activated carbon filter. We don't apply the Nano figures to it. Compare
Why filter water that is already good?
Tap water in your area is controlled and safe to drink. Filtering is about what happens between the plant and your glass: old pipes, chlorine taste, limescale, and substances regulations are still catching up on, like PFAS and microplastics. It is a choice, not a necessity.
Questions
Does it remove fluoride?
Yes. In a dedicated test, fluoride went from 1 mg/L to not detected after filtration: 99.9% reduced.
Does it filter PFAS?
20 PFAS were tested on the Nano filter. None were detected after filtration.
Does it remove limescale?
It reduces limescale in the kettle, tea and coffee, thanks to the limescale stage in every Tap System filter. It does not soften the water.
How can a small filter do this?
Multi-stage filtration: activated carbon for chlorine and taste, and dedicated stages for the rest. The lab measures the result, not the promise.
Still need help?
Most answers are in our Help Center: fitting, filters, subscription, delivery and returns. Otherwise, write to customercare@puurefilters.com with your order number. We'll find the best solution with you.
