Do Water Filters Remove PFAS? (UK Evidence Explained)
This guide was written by Keith, a mechanical engineer with over 20 years of hands-on experience working with reverse osmosis and water filtration systems.
A calm, evidence-based guide by FilterAuthority.co.uk
PFAS — often called "forever chemicals" — are increasingly discussed in relation to drinking water. A common question UK households ask is:
Do water filters actually remove PFAS — or is it just marketing?
The honest answer is:
Some filters can significantly reduce PFAS. Many cannot.
This guide explains which types work, which don't, and why, using UK-relevant context and real-world engineering considerations — not hype.
What Are PFAS (Quick Recap)
PFAS (Per- and polyfluoroalkyl substances) are a large group of man-made chemicals used in:
- Non-stick cookware
- Waterproof fabrics
- Food packaging
- Firefighting foams
- Industrial processes
They are called "forever chemicals" because they do not break down easily in the environment or the human body.
In the UK, PFAS have been detected in some water sources, though testing and reporting vary by region. There are currently no statutory standards for PFAS in drinking water in England and Wales, though the Drinking Water Inspectorate (DWI) has produced precautionary guideline values.
Does Boiling Water Remove PFAS?
No.
PFAS are heat-stable, meaning:
- Boiling kills bacteria
- Boiling does not remove PFAS
- Concentrations may actually increase slightly as water evaporates
Boiling is essential for baby formula preparation — but it is not a PFAS solution.
Which Water Filters Can Reduce PFAS?
Only two filtration technologies have consistently shown meaningful PFAS reduction:
1️⃣ Activated Carbon
(Solid carbon block)
2️⃣ Reverse Osmosis
(RO)
Other filter types may improve taste or clarity, but do not reliably address PFAS.
Carbon Filters and PFAS
Do carbon filters remove PFAS?
Yes — some do, but performance varies greatly.
What matters
- Solid carbon block, not loose granular carbon
- Sufficient contact time
- Regular cartridge replacement
What carbon filters are good at
- Reducing long-chain PFAS (e.g. PFOS, PFOA)
- Improving taste and odour
- Reducing chlorine and some organic chemicals
Limitations
- Less effective for some short-chain PFAS
- Performance drops as the filter becomes exhausted
- Not all products are tested or transparent
From an engineering perspective, carbon filters are effective but maintenance-sensitive.
Reverse Osmosis (RO) and PFAS
Does RO remove PFAS?
Yes — reverse osmosis is considered the most effective domestic filtration method for PFAS reduction.
RO membranes physically block PFAS molecules, along with:
- Heavy metals
- Nitrates
- Microplastics
- Many dissolved contaminants
Important context
RO systems:
- Treat drinking water at a single tap
- Do not treat the whole house
- Require sufficient pressure and maintenance
RO is best viewed as a high-protection drinking water solution, not a universal fix.
Filters That Do NOT Reliably Remove PFAS
These are commonly misunderstood:
Jug filters (e.g. standard BRITA)
- Improve taste
- Reduce chlorine
- Do not reliably reduce PFAS
Sediment filters
- Remove particles
- No effect on dissolved chemicals
UV filters
- Kill bacteria
- Do not remove chemicals
Water softeners
- Reduce limescale
- Do not remove PFAS
Carbon vs RO for PFAS — Which Is Better?
| Factor | Carbon Filter | Reverse Osmosis |
|---|---|---|
| PFAS reduction | Moderate–High | Very High |
| Whole-house use | Possible | No |
| Installation | Simple | More complex |
| Cost | Lower | Higher |
| Maintenance | Regular cartridge changes | Membrane + filters |
| Best for | General reduction & taste | Maximum protection |
Many UK households choose:
- Carbon for everyday use
- RO for drinking and cooking
Do You Need a PFAS Filter in the UK?
There is no one-size-fits-all answer.
Filtering may be worth considering if:
- You live near industrial or military sites
- You want to reduce long-term chemical exposure
- You're preparing baby formula
- You prefer additional peace of mind
Filtering may be unnecessary if:
- Your water supplier reports consistently low levels
- You are comfortable with current testing standards
This is a personal risk decision, not an emergency.
Engineering Perspective
From an engineering standpoint, PFAS removal is about matching technology to the problem.
- Carbon relies on adsorption and requires maintenance discipline
- RO relies on physical separation and requires pressure and system integrity
- No domestic filter works indefinitely without care
Claims of "PFAS removal" without explanation or test data should be treated cautiously.
A Calm Summary
- Some water filters can reduce PFAS
- Many popular filters cannot
- Boiling does not remove PFAS
- Carbon and RO are the only proven domestic options
- RO offers the highest reduction, but is not always necessary
About the Author
Keith is a trained mechanical engineer with over 20 years of hands-on experience working with reverse osmosis (RO) and water filtration systems.
At FilterAuthority, he focuses on clear, UK-specific guidance that helps households make informed decisions without pressure or exaggeration.