Why is chlorine added to tap water?

Chlorine is added to UK tap water as a disinfectant to kill bacteria, viruses, and other harmful microorganisms. It provides "residual protection" — meaning it continues to disinfect the water as it travels through miles of pipes from the treatment works to your tap, preventing recontamination.

Is chlorine in tap water safe to drink?

Yes. The amount of chlorine in UK tap water is very small (typically 0.2-0.5 mg/l) and is well within safe limits. The UK legal limit is 5 mg/l, though water companies aim to use the minimum amount necessary. At these levels, chlorine poses no health risk.

How do I remove chlorine taste from tap water?

The simplest method is to fill a jug with tap water and leave it in the fridge for a few hours — chlorine dissipates naturally. A standard carbon filter jug (like Brita) also removes chlorine effectively. For the whole house, a carbon filter on the mains supply works well.

Does chlorine in water affect hair and skin?

Chlorine can dry out hair and skin, particularly at higher concentrations or with frequent exposure (like daily showering). It strips natural oils, which can make hair feel brittle and skin feel tight or itchy. A vitamin C shower filter is an effective and affordable solution.

Chlorine in Tap Water UK: Why It's Added & How to Remove It

Why is Chlorine in UK Tap Water?

Every UK water company adds chlorine (or a related compound called chloramine) to treated water before it enters the distribution network. This is a legal requirement to ensure water remains safe to drink as it travels through the pipe network — which can be several miles from the treatment works to your tap.

Chlorine provides residual disinfection, meaning it continues killing bacteria and viruses throughout the journey. Without it, there would be a risk of microbial contamination from biofilms inside pipes, minor leaks, or during repair work.

How Much Chlorine is in UK Tap Water?

Typical UK tap water contains 0.2-0.5 mg/l of free chlorine. The legal maximum is 5 mg/l, but water companies rarely exceed 1 mg/l. The amount you receive depends on how far you are from the treatment works — homes closer to the source may taste more chlorine, while homes further away receive less as it dissipates along the way.

Is It Safe?

At the levels used in UK water treatment, chlorine is safe to drink. The WHO, DWI, and all major health authorities agree on this. The small amount used for disinfection is far outweighed by the protection it provides against waterborne diseases.

A minor concern is disinfection byproducts (DBPs) like trihalomethanes (THMs), which form when chlorine reacts with natural organic matter in the water. UK water companies monitor THMs closely, and levels are kept well within legal limits.

Chlorine Taste and Smell

The most common complaint about chlorine is its taste and swimming-pool smell. Some people are more sensitive than others. If the chlorine taste bothers you:

Fill a jug and refrigerate: Chlorine evaporates naturally within a few hours
Use a carbon filter jug: Activated carbon removes chlorine and improves taste instantly
Fit a tap filter: Attaches to your kitchen tap for continuous filtered water

Effects on Hair and Skin

Chlorine strips natural oils from hair and skin. Regular exposure through showering can cause:

Dry, brittle hair and faded hair colour
Dry, itchy skin, particularly for people with eczema or sensitive skin
Irritation for people with certain skin conditions

A vitamin C shower filter neutralises chlorine before it contacts your skin and hair. They cost around 15-30 pounds and last 2-3 months per cartridge.

Effects on Fish and Aquariums

Chlorine is toxic to fish at any concentration. If you keep fish, always treat tap water with a dechlorinator before adding it to your tank. This applies to water changes and top-ups.

Check Your Water's Chlorine Level

Enter your postcode on WaterGrade to see the chlorine measurement for your supply zone.