The Science Explained (Plus Better Alternatives)
Yes, boiling water removes chlorine—but you need to maintain a rolling boil for 15-20 minutes. Simply boiling a kettle isn't enough. For practical daily use, a carbon filter is much more efficient.
Chlorine is a volatile compound—it evaporates easily when heated. At 100°C (boiling point), chlorine gas escapes from the water into the air. The longer you boil, the more chlorine evaporates.
However, there's a catch: chlorine doesn't instantly disappearthe moment water boils. It takes time for the chlorine molecules to reach the surface and escape. That's why you need a sustained rolling boil, not just a quick boil.
Note: These times assume standard UK chlorine levels (up to 0.5mg/L)
Some UK water companies use chloramine instead of chlorine. Chloramine is chlorine bonded to ammonia—it's more stable and doesn't evaporate with boiling.
If your water contains chloramine, boiling won't help. You'll need a catalytic carbon filter or reverse osmosis system.
How to check: Contact your water company or check their annual water quality report. They're required to disclose which disinfectant they use.
Let's be honest: boiling water for 15-20 minutes every time you want a drink is impractical. Here are more sensible options:
Removes chlorine instantly as water passes through. Also removes taste, odour, and some other contaminants. A filter jug costs £20-40, tap-mounted filters £30-60.
Effectiveness: Removes 97-99% of chlorine | Works on chloramine: Only catalytic carbon
Chlorine naturally dissipates from water left in an open container. Takes about 24 hours at room temperature. Good for watering plants or filling fish tanks, but impractical for drinking water.
Effectiveness: 80-90% after 24 hours | Works on chloramine: No
A tiny amount of vitamin C neutralises chlorine almost instantly. Some people add a pinch to bath water or use vitamin C shower filters. Not practical for drinking water as it changes the taste.
Effectiveness: 99%+ instantly | Works on chloramine: Yes (but needs more)
| Method | Time | Cost | Removes Chloramine? | Practical? |
|---|---|---|---|---|
| Boiling (15-20 min) | 15-20 min | Energy cost | ✗ | ✗ |
| Carbon filter | Instant | £20-60 | ~ (catalytic only) | ✓ |
| Standing water | 24 hours | Free | ✗ | ✗ |
| Vitamin C | Instant | Cheap | ✓ | ~ (changes taste) |
Yes, boiling water does remove chlorine. Chlorine is a volatile compound that evaporates when heated. However, you need to maintain a rolling boil for 15-20 minutes to remove most of the chlorine. Simply bringing water to a boil and turning off the heat won't be enough.
You need to boil water for 15-20 minutes at a rolling boil to remove most chlorine. The exact time depends on the initial chlorine concentration and the volume of water. For a kettle's worth of water, 15 minutes is usually sufficient. Note that this is impractical for daily use—a carbon filter is much more efficient.
No, boiling does NOT effectively remove chloramine. Chloramine (chlorine bonded to ammonia) is much more stable than free chlorine and doesn't evaporate easily. Some UK water companies use chloramine instead of chlorine. If your water contains chloramine, you'll need a catalytic carbon filter or reverse osmosis system to remove it.
The fastest practical method is using a carbon filter—either a filter jug, tap-mounted filter, or under-sink system. These remove chlorine instantly as water passes through. Alternatively, leaving water in an open container for 24 hours allows chlorine to naturally dissipate, but this is slow and impractical for drinking water.
A standard kettle brings water to a boil and then switches off—this isn't long enough to remove significant chlorine. The water needs to be at a rolling boil for 15-20 minutes. Some kettles with 'keep warm' functions could theoretically work, but it's impractical and wastes energy. A filter is much more efficient.
At the levels used in UK tap water (up to 0.5mg/L), chlorine is not considered harmful to health. It's added to kill bacteria and make water safe. However, some people are sensitive to the taste and smell, and there are concerns about disinfection byproducts (DBPs) formed when chlorine reacts with organic matter. If you're concerned, a carbon filter effectively removes both chlorine and most DBPs.
Yes, boiling removes chlorine—but it's impractical for daily use. If chlorine taste bothers you, a simple carbon filter jug (£20-40) is the most sensible solution. It removes chlorine instantly, improves taste, and requires no waiting or energy costs.
If your water company uses chloramine instead of chlorine, boiling won't help at all. You'll need a catalytic carbon filter or reverse osmosis system.
More Chlorine Solutions →Water Filtration Specialist | 24+ Years Experience
Keith has spent over two decades helping people understand water quality and find practical solutions for their homes.
Read full bioInformation accurate as of January 2026. Chlorine levels and disinfection methods vary by water company. Check with your local supplier for specific information.