Your tap water smells like a swimming pool, or you taste a faint chemical note. Chlorine. But where does it come from, is it genuinely harmful, and how do you remove it most effectively? In this article we set out all the facts: from the situation in the Netherlands to the best filter options, including an honest comparison table and seven frequently asked questions.
What is chlorine in tap water?
Chlorine (Cl) is a chemical disinfectant that drinking water companies use to kill bacteria, viruses and other micro-organisms in drinking water. It has been used safely for more than a hundred years and has pushed back diseases such as cholera and dysentery worldwide. In drinking water, chlorine occurs as free chlorine (hypochlorite) or as chloramine (a combination of chlorine and ammonia). The two forms differ in odour, in taste and in how easily they are filtered out.
The reason chlorine is added to drinking water is twofold. First, it disinfects the water at the treatment plant itself. Second, what is known as residual disinfection keeps the water protected against recontamination while it travels through the mains network. The longer the network, the more chlorine is needed to prevent bacterial growth along the way.
Is there chlorine in Dutch tap water?
Good news if you live in the Netherlands: most drinking water companies here add no chlorine to tap water at all. That is unusual by international standards. Thanks to modern treatment techniques such as UV light, ozone treatment and ultrafiltration, chlorine is superfluous in most cases. According to the RIVM (the Dutch national institute for public health and the environment), Dutch drinking water is among the cleanest in the world.
There are nuances, though. A small number of drinking water companies, particularly in areas that depend heavily on surface water (river water), occasionally use low concentrations of chlorine dioxide or chloramine as an extra layer of safety. Vewin, the trade association of the Dutch drinking water companies, reports that in those cases the concentrations generally stay below 0.1 mg/L, well under the European drinking water limit of 0.3 mg/L.
In cities such as Amsterdam and Rotterdam, where water from the Rhine plays a larger part in the supply, the chance of a slight chlorine taste is therefore a little greater than in Eindhoven or Breda, where deep groundwater forms the basis. Chlorine is not the only substance in tap water that prompts debate, incidentally: questions come up just as regularly about fluoride in tap water.
Why does tap water sometimes smell or taste of chlorine?
Chlorine is colourless but has a characteristic odour that resembles swimming pool water or bleach. A few factors make that smell and taste stronger:
- Warm weather: at higher temperatures chlorine evaporates faster and more of the odour is released.
- Morning water: water that has stood in the pipes all night contains higher concentrations of chlorine compounds and by-products.
- New or repaired mains: after maintenance, water companies sometimes flush the pipes through with a temporarily higher chlorine concentration.
- Chloramine: water containing chloramine has a slightly different, sharper odour than water with free chlorine, and is harder to remove by simply letting it stand.
At PureFilter we see that customers who install a filter are often surprised by how different the water tastes, even when they thought their tap water had no off-note at all. The combination of chlorine removal and mineral addition makes a noticeable difference to the daily experience of drinking water.
Is chlorine in tap water harmful to your health?
At the concentrations found in Dutch tap water, chlorine itself is not directly harmful. The limits applied are conservative and rest on decades of scientific research. Even so, there are two points worth mentioning.
Trihalomethanes (THMs)
Chlorine reacts with organic matter naturally present in water and forms by-products in the process, the so-called trihalomethanes (THMs). The best known is chloroform. Research by the National Cancer Institute links long-term high exposure to THMs through drinking water to a slightly raised risk of bladder cancer. In the Dutch context, THM concentrations in tap water are generally low and comfortably within the legal limits, but zero is zero: the only way to be certain you take in no THMs is to filter them out.
Chloramine and ammonia
Chloramine is more stable than free chlorine and breaks down more slowly. At higher concentrations it can irritate the airways of people with a sensitive respiratory system. Chloramine is also harmful to fish and to people undergoing kidney dialysis; hospitals and aquarium keepers are therefore required to remove it completely. A good carbon-block filter with sufficient contact time removes chloramine effectively; a simple jug filter does not always manage it.
How do you remove chlorine from tap water?
There are several ways to get chlorine out of tap water. They differ widely in effectiveness, convenience and cost.
Letting water stand
Free chlorine evaporates by itself if you leave a jug of water uncovered for an hour or longer. This works reasonably well for free chlorine but not for chloramine, which is far more stable. Water that stands for a long time also brings a bacterial risk with it, and other contaminants (PFAS, pharmaceutical residues, heavy metals) are not removed this way.
Boiling
Boiling water evaporates free chlorine almost completely. Chloramine partly breaks down when boiled. The drawbacks: you have to wait for the water to cool, energy use adds up, and boiling removes no PFAS, lead or pharmaceutical residues either.
Jug filter (Brita, for example)
A jug filter with activated carbon noticeably reduces the chlorine taste and is affordable to buy. The limitations: filter capacity is low (typically 100 to 150 litres per cartridge), chloramine is removed less effectively, and PFAS or pharmaceutical residues are not filtered out by most jug filters. A jug filter also adds no minerals.
Inline carbon-block water filter
An inline water filter is connected to the water supply under the worktop and filters all the water that comes out of the tap, before it reaches your glass. A quality carbon-block filter removes free chlorine, chloramine, THM by-products, PFAS, microplastics, lead and more than 100 other substances in a single step, the moment you draw water. If you would like to see the different filter types side by side first, our overview explains how a water filter works and which type suits which situation.
The PureFilter Mineral+ goes a step further: thanks to the built-in Swedish Mineral Rock™ technology it adds calcium, magnesium and potassium to the water after filtering. That gives you water that is cleaner than tap water and richer in useful minerals. Installation takes 5 to 10 minutes, filter capacity is 15,000 to 20,000 litres per filter cartridge, and the PureFilter is certified to NSF 42, 53, 61 and 372.
Chlorine, PFAS, microplastics and minerals in one filter
The PureFilter Mineral+ installs in 5 minutes and filters more than 100 contaminants.
Comparison: which water filter removes chlorine best?
The table below compares the most widely used methods for taking chlorine and other contaminants out of tap water.
| Method | Free chlorine | Chloramine | THMs | PFAS | Minerals added | Convenience |
|---|---|---|---|---|---|---|
|
PureFilter Mineral+ NSF 42/53/61/372 |
✓ Yes | ✓ Yes | ✓ Yes | ✓ Yes | ✓ Ca, Mg, K | Automatic |
| Brita jug filter | ~ Largely | ✗ Limited | ✗ No | ✗ No | ✗ No | Fill by hand |
| ZeroWater filter | ✓ 95 to 99% | ~ Partly | ~ Partly | ~ Partly | ✗ No | Fill by hand |
| Letting water stand | ~ Partly | ✗ No | ✗ No | ✗ No | ✗ No | Long wait |
| Boiling | ✓ Yes | ~ Partly | ✗ No | ✗ No | ✗ No | Has to cool down |
| No filter | ✗ No | ✗ No | ✗ No | ✗ No | ✗ No | N/A |
The PureFilter Mineral+ is the only one able to remove both chlorine and chloramine, filter out THM by-products and PFAS, and add minerals at the same time. That makes it the most complete choice for anyone who wants genuinely clean, good-tasting water without the bother of filling jugs or waiting.
Frequently asked questions about chlorine in tap water
Is there chlorine in Dutch tap water?
In the Netherlands, most drinking water companies add no chlorine to tap water. A number of companies do use small amounts of chlorine dioxide as an extra layer of safety, but the concentrations are so low that they are barely measurable. That puts Dutch tap water among the lowest-chlorine drinking water in the world. You will find more information on the website of the RIVM.
Why does tap water sometimes taste of chlorine?
Chlorine is added deliberately as a disinfectant during transport. The smell is strongest in warm weather and in the water that comes out of the tap first thing in the morning, because that water has stood still the longest. Cities that use surface water (Amsterdam, Rotterdam, The Hague) generally have more of a chlorine taste than cities on deep groundwater (Eindhoven, Breda, Groningen).
Is chlorine in tap water harmful to your health?
At the concentrations found in Dutch tap water (generally below 0.1 mg/L), chlorine itself is not directly harmful. Chlorine does react with organic matter in water, however, and forms trihalomethanes (THMs) such as chloroform in doing so. With long-term high intake, THMs are associated with a slightly raised risk of bladder cancer, although Dutch concentrations rarely exceed the limit.
What is the difference between chlorine and chloramine?
Free chlorine is the most common form of disinfection in drinking water. Chloramine (a combination of chlorine and ammonia) is more stable and is sometimes used in addition. Chloramine is harder to remove than free chlorine: simply letting the water stand does not work. Only carbon-block filters with sufficient contact time remove chloramine effectively.
Does a Brita filter remove chlorine?
Yes, a Brita jug with an activated carbon filter removes free chlorine for the most part and noticeably reduces the off-taste. However: a Brita removes chloramine less effectively, filters out no PFAS or pharmaceutical residues, and adds no minerals. An inline carbon-block filter such as the PureFilter Mineral+ offers broader protection and is considerably more efficient per litre. See also our detailed comparison at PureFilter vs. Brita.
How quickly does a water filter remove chlorine?
A carbon-block inline water filter such as the PureFilter Mineral+ removes chlorine the moment you draw water, with no waiting time. Letting water stand takes an hour at the very least and does not work for chloramine. Boiling costs minutes and energy, and after that the water still has to cool down.
Does the PureFilter add minerals after filtering as well?
Yes, that is the distinctive quality of the PureFilter Mineral+. The built-in Swedish Mineral Rock™ technology adds calcium, magnesium and potassium to the filtered water. That gives you water that is cleaner than tap water and richer in useful minerals than most bottled waters, for a fraction of the cost.
Conclusion: filtering chlorine pays off, in the Netherlands too
Dutch tap water is of excellent quality and contains virtually no chlorine in most regions. Even so, in some cities and in warm weather there is a noticeable chlorine taste, caused by residual disinfection and the formation of chloramine or THM by-products. The simplest, most effective and most complete solution is a certified carbon-block inline water filter.
The PureFilter Mineral+ removes chlorine, chloramine, PFAS, microplastics, heavy metals and more than 100 other contaminants, and adds calcium, magnesium and potassium at the same time through Swedish Mineral Rock™. Installation takes 5 to 10 minutes, the price is €149.00 including the first filter, and replacement filters are available from €65.00. Have a look at the frequently asked questions on purefilter.nl for more information.
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Install the PureFilter Mineral+ in 5 minutes and enjoy cleaner, better-tasting water straight away.