Chlorine has an unpleasant chemical taste and smell, and most of us would rather not drink it in our water. Unfortunately, if you’re on a public drinking water supply, chlorine in drinking water is something you’re probably very familiar with.
We don’t blame you if you’re considering boiling your water to remove chlorine. But does it work? Does boiling water remove chlorine, or are you better off using another, easier solution to eliminate this chemical from your water supply?
📖 TL;DR
The short answer is yes, boiling water can remove free chlorine. However, this process is lengthy, and can’t be used to remove chlorine that’s combined with other chemicals, like ammonia. So, if your water is disinfected with chloramine, you can’t remove it by boiling.
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♨️ How Does Boiling Water Remove Chlorine?
For water to boil, it has to be exposed to a high heat of 212°F. This heat doesn’t only cause water to evaporate – it also causes chlorine to evaporate. This is because, at a high temperature, water is unable to hold chlorine.
How long does it take to remove chlorine by boiling your water? On average, it takes about four minutes to remove 1 mg of chlorine in a 10-gallon batch of water. So, if you want to use this method yourself, you need to know how much chlorine your water contains, so you know how long to boil it.
Can you eliminate chlorine by boiling chlorinated water? Perhaps – if you boiled your water for a really long time. But you’d have no real way to know.
✅ Is Boiling Water Effective in Removing Chlorine?
Yes, you can effectively remove chlorine from water by boiling it, but there are a few issues with this method.
First, you can’t be exactly sure how much chlorine is being removed from your chlorinated water, and at what rate, during the boiling process. Chlorine vapor is invisible, and you won’t smell it in trace amounts, either. This means you won’t be able to accurately remove chlorine from water.
Second, boiling tap water takes a long time. You’ll have to wait at least four minutes for a batch of water to boil long enough to remove chlorine. The process is clunky – you’ll have to fill a pan or kettle, switch on your stove, wait for the water to boil, then wait for it to cool and decant it into separate containers.
Third, boiling water only removes free chlorine. Free chlorine is chlorine that’s on its own, and not bound to another chemical element. Water supplies that are disinfected with chloramine – a mixture of free chlorine and ammonia – can’t be boiled to remove the chemicals.
🤔 How to Know if Boiling Water Has Removed Chlorine
The only way to know whether you’ve removed chlorine by boiling is to test your water before and after the boiling process.
Use an at-home chlorine test kit to test your tap water before doing anything to it. Make a note of its chlorine content, then boil your water. Wait for the water to cool, then test it again and compare your results. You should hopefully see that your water’s chlorine levels are much lower.
📰 Alternative Ways to Remove Chlorine From Water
Boiling your water is a viable means of removing chlorine, but it’s not the quickest or most practical solution. Plus, it won’t remove any other contaminants (aside from killing bacteria, which is highly unlikely to be found in chlorinated water).
Instead, look at these simple, cost-effective chlorine removal solutions.
Reverse Osmosis
Reverse osmosis isn’t only the best solution for removing chlorine – it removes hundreds of other contaminants, too, and can effectively purify water.
In the RO process, water flows through several water filters, including an activated carbon filter, an RO membrane, a sediment filter, and a post-filter.
There are two stages in reverse osmosis filtration that get rid of chlorine: the activated carbon filter, which removes chlorine by adsorption; and the RO membrane, which has tiny pores that block chlorine from passing through to the other side.
Reverse osmosis is ideal for removing both chlorine and chloramine, so if you’re also looking for chloramine removal, RO is a great solution.
There are only a couple of issues with RO to be aware of. First, most reverse osmosis water filter systems are installed underneath your kitchen sink or on the countertop, so they’re not ideal if you want a whole-home system that can eliminate chlorine gas from your showers. Plus, these filters are expensive, costing around $400 on average.
Carbon Filters
There are three types of carbon filters that can be used to dechlorinate water: activated carbon, standard carbon, and activated charcoal filter cartridges.
Carbon in activated form is most commonly used to reduce chlorine, although this type of carbon can’t be used to remove chloramine from tap water. AC uses a process called adsorption to grab onto dissolved gas particles, pulling them out of the water.
Activated charcoal filters have similar effects, but they’re not quite as effective or popular as AC filters.
You can find carbon water filter cartridges in whole home, under-sink, faucet, and water pitcher filters. Carbon media is also available in whole home tank-based systems, with a much bigger surface area and longer lifespan than carbon cartridges.
Distillation
Distillation involves boiling water to remove contaminants, leaving only pure water molecules behind.
A chamber is used for boiling the water. When water evaporates into a vapor, it rises, and moves through a cooling corridor, condensing into a separate container.
When you boil water, most impurities are unable to vaporize with water. Chlorine can vaporize – but it can’t condense back into liquid form with water, so it remains trapped in the distiller. Most distillers use a charcoal filter that can remove impurities that make it through the distillation process, including low levels of chlorine.
Although distillation is one of the most effective methods of reducing chlorine concentration, we wouldn’t recommend it. The distilling process takes up to 6 hours to purify just one gallon of water.
UV Light
Ultraviolet light is most commonly used to kill bacteria and other harmful substances in water. Most people don’t realize that, as well as targeting microorganisms, UV light between 180 and 400 nm wavelengths can also be used to eliminate chlorine from tap water.
Most at-home UV purification lights are installed as whole-home solutions. You can install a UV lamp as a standalone water treatment unit or install it as a post-treatment unit for another whole home system, like a water softener.
🧠 Boiling Water Chlorine Removal FAQs
Is removing chlorine and chloramine from tap water essential?
No – not if you just plan to drink your tap water. According to the EPA, up to 4.0 ppm of chlorine, and the same amount of chloramine, is safe in water. Chlorine and chloramine are widely used for disinfection purposes, and offer an affordable and effective method of killing microbes like bacteria and viruses. Small amounts of chlorine are said to be harmless – but you might still prefer not to drink them.
You will need to remove chlorine from tap water if you plan on using the water in aquariums or for dialysis treatment.
What are the health risks of chlorine?
There are no known health risks associated with drinking chlorinated tap water, although high levels of this chemical can irritate the skin, eyes, and airways.
Does rain water contain chlorine?
No. Chlorine is added to large volumes of water during the chemical disinfection process in water treatment. This chemical isn’t found in rainwater or well water.
Can you reduce chlorine by leaving water out?
Yes. If you leave a gallon of water out for 24 hours, the chlorine will naturally evaporate. This isn’t ideal if you want instant access to chlorine-free drinking water, and you’ll need to leave a large surface area of water exposed to the air for it to be effective – but it’s still an option to consider in an emergency.
Can you remove chlorine from water with neutralizing additives?
Yes, there are certain neutralizing additives that can be used to remove chlorine. Sodium metabisulphite, which counteracts and kills chlorine, is one of the most effective additives. However, using neutralizing additives isn’t a common household practice – it’s typically used in the semiconductor and pharmaceutical industries.
Does bottled water contain chlorine?
Some bottled waters contain chlorine, and some don’t. It depends on how the water has been treated, and to what extent.
