How Long to Boil Tap Water to Remove Chlorine? The Ultimate Guide

Have you ever noticed a strong chemical taste or smell coming from your tap water? That‘s likely chlorine added by your municipality to disinfect the water supply. While important for public health, some find this chlorine unpleasant when drinking or cooking. Boiling tap water is one simple and effective way to remove much of that lingering chlorine taste and odor.

In this comprehensive guide, we’ll explore the science behind using boiling water to remove chlorine. You’ll learn step-by-step instructions, optimal boiling times, plus pros and cons of boiling versus other chlorine removal methods. We’ll also cover safety tips and common questions when it comes to boiling out chlorine in your tap water.

With this guide, you’ll be able to confidently boil away chlorine for cleaner, better tasting water.

Why Is There Chlorine in Tap Water?

The addition of chlorine to public drinking water supplies dates back to the early 20th century, when chlorine disinfection helped curb deadly cholera and typhoid outbreaks that had ravaged many North American and European cities.

Today, over 98% of U.S. water utilities now use some form of chlorine-based disinfectant in their treatment process. The predominant methods used are:

• Chlorine gas: Accounting for 62% of chlorination methods

• Sodium hypochlorite liquid: 31%

• Calcium hypochlorite or bleach powder: 7%

This chlorination is regulated by the EPA under the Safe Drinking Water Act at concentrations typically between 0.2 to 1 part per million. Such trace chlorine levels help kill harmful pathogens like E. coli, Salmonella, Giardia intestinalis, and rotaviruses that can infect drinking water sources and pipelines.

Chlorination makes water safe to drink by virtually eliminating risks from bacterial, viral, and protozoan waterborne diseases. This has drastically reduced outbreaks of serious illnesses like cholera, dysentery, and typhoid fever in countries that use chlorinated public water supplies.

However, while chlorine in small concentrations is highly effective at disinfecting water, some find its taste and odor unpleasant. The detectable “chlorine” flavor many associate with tap water can clash when used in cooking and be unpalatable as a beverage. Fortunately, there are some simple methods to remove much of that residual chlorine from your water.

Is Boiling Water Effective for Chlorine Removal?

Boiling water is an easy, inexpensive, and effective method for removing a significant portion of chlorine. This is because chlorine is volatile, rapidly changing from liquid to gas when heated.

As water is brought to a rolling boil, chlorine dissipates out of the water and enters the air as a gas. Testing has shown this can eliminate 60% to 98% of chlorine, depending on boiling time and testing method used.

One study from the Water Quality Research Foundation boiled tap water contaminated with 1 part per million chlorine for 5-20 minutes. They found:

• After 5 minutes boiling: chlorine reduction of 61%
• After 10 minutes: 80% reduction
• After 20 minutes: 98% reduction

Another study in the International Journal of Food Sciences and Nutrition looked at 10-minute boiling times. Results showed boiled water had a 92.8% decrease in chlorine versus non-boiled tap water.

Higher temperatures increase chlorine removal, as hotter water quickens evaporation. Therefore, longer boiling times are more effective, but with diminishing returns after 10 minutes.

Based on the research, boiling your tap water for 5-10 minutes should eliminate over 90%+ of chlorine, while still being reasonably quick and energy efficient. Continue reading for step-by-step guidelines.

Step-by-Step Guide to Removing Chlorine by Boiling

Boiling tap water is straightforward. But optimal chlorine reduction depends on using the proper method. Follow these steps:

1. Use a Clean Cooking Pot or Kettle

Any heat-safe cooking vessel will work, along with electric kettles. Use clean pots and kettles only used for food purposes. Start with fresh cool water directly from your tap.

Tip: Glass and stainless steel pots allow you to observe the rolling boil without chemical leaching risks.

2. Bring Water to a Full Rolling Boil

Heat on a stovetop or in an electric kettle until rapidly boiling. Bubbles should be continually rising and “rolling” throughout the pot. This ensures the water reaches the 212°F (100°C) temperature where chlorine readily vaporizes.

3. Maintain Rolling Boil for 5-10 Minutes

Maintaining the high-temperature rolling boil for 5-10 minutes allows time for chlorine concentrations to significantly decrease as it evaporates into the air.

Set a timer and keep the water at a boil for at least 5 minutes. 10 minutes provides maximum chlorine reduction.

4. Turn Off Heat and Allow Water to Cool

Chlorine gases can re-absorb into the water if consumed immediately after boiling. Turn off the heat source and allow the water to cool and come down to room temperature.

5. Store in Air-Tight Bottle or Jug

Once cooled, transfer boiled water into air-tight bottles or jugs with caps. This prevents re-absorption of chlorine gases from the atmosphere. Store in refrigerator and use within 1-2 days for optimal quality.

And that’s it! Now you have chlorine-free water ready for drinking and cooking.

How Long Should You Boil Water to Remove Chlorine?

• Minimum of 3-5 minutes boiling for minor chlorine reduction
• 5-10 minutes boiling removes 60-98%+ of chlorine
• Over 10 minutes provides diminishing returns

The required time depends on:

• Amount of water – Smaller amounts may boil faster. Large volumes need longer.

• Chlorine concentration – Higher levels require more time to dissipate.

• Desired reduction – Longer boiling means less chlorine, but takes more time.

Test the boiled water’s taste. If the chlorine odor/flavor remains noticeable, try boiling a few more minutes.

Other Methods to Remove Chlorine

While boiling is an easy go-to, there are alternative methods to remove chlorine from drinking water:

Activated Carbon Filtration

Filtration using activated carbon is one of the most common and effective methods. Carbon adsorbs and binds to chlorine, removing it from water. Carbon filters are used in whole-house systems, faucet attachments, pitchers, and reverse osmosis systems.

Carbon filters must be replaced periodically as the binding sites become occupied. Usage time depends on water quality and volume.

Standing Exposed

Simply leaving water in an open container allows chlorine to naturally dissipate into the air over time. Approximately 50% of chlorine will off-gas if left standing uncovered for 24 hours, increasing to 75% after 48 hours. This passive method requires no energy input.

Reverse Osmosis

RO membrane systems can remove 95-99% of chlorine compounds through a combination of mechanical filtration and diffusion. However, water recovery is limited, requiring 2-3 gallons of water filtered to produce 1 gallon of permeate water.

Distillation

The boiling and steam condensation process of distillation effectively leaves chlorine behind, producing highly purified water. However, it requires significant energy.

Chemical Neutralization

Chlorine neutralizing chemicals containing sodium thiosulfate or sodium sulfite instantly bind with chlorine to convert it into harmless byproducts. These are commonly used to dechlorinate tap water for aquariums.

Pros and Cons of Boiling vs. Other Chlorine Removal Methods

Boiling

Pros:

• Simple, easy, and inexpensive
• No equipment or installation needed
• Removes 60-98%+ of chlorine
• Makes water safer by killing microbes

Cons:

• Time consuming for large volumes
• Does not remove other contaminants
• Can concentrate mineral impurities

Carbon Filtration

Pros:

• Simple process for whole house or drinking water
• Readily available pitchers and attachments
• Removes a wide range of contaminants
• Long filter lifetime with regular replacement

Cons:

• Higher upfront cost than boiling
• Ongoing filter replacement required
• Rate limited by water flow through filter

Reverse Osmosis

Pros:

• Thorough removal of 95-99% of chlorine
• Also removes many inorganic contaminants
• Automated treatment of all household water

Cons:

• High initial purchase and installation cost
• Significant water waste (up to 2:1)
• Regular filter replacements required

Distillation

Pros:

• Extremely effective at chlorine and contaminant removal
• Produces pure distilled water

Cons:

• Very high energy use
• Slow production rate
• Needs boiling flasks and condenser equipment

Dechlorination Chemicals

Pros:

• Instantly eliminates chlorine
• Inexpensive for small volumes

Cons:

• Must buy ongoing chemical supplies
• Adds chemicals to water
• Not effective for large volumes

As you can see, each method has its own advantages and limitations. For simply removing chlorine, boiling is the most accessible option. Filtration and reverse osmosis provide more complete water treatment, while distillation and chemical addition have more limited applications.

Should You Filter Water After Boiling?

Since boiling only targets chlorine removal, adding a filtration step after boiling provides more comprehensive water purification.

Activated carbon filters adsorb trace chlorine missed by boiling. They also remove other contaminants like heavy metals, sediment, VOCs, and microplastics that boiling leaves behind.

Microporous ceramic filters are also excellent at catching particulates. Water softening using ion exchange resins can remove excess calcium and magnesium ions.

Reverse osmosis takes filtration a step further for 99%+ impurity reduction. Distillation also purifies boiled water.

A simple activated carbon drinking water filter, whether countertop or pitcher style, improves on boiled water’s taste and quality at an affordable cost. For health-sensitive individuals or times of compromised source water quality, using an additional purification step is recommended.

Is It Safe to Drink Boiled Tap Water?

Drinking properly boiled tap water is generally safe, with the caveat that boiling alone does not remove inorganic contaminants.

The starting water quality before boiling is the most significant factor. Always use an approved, tested municipal water source free of detected microbiological and chemical impurities. Boiling can then make this clean tap water even safer by killing any remaining pathogens.

However, if lead, nitrates, arsenic, MTBE, or other concerning contaminants are detected in your underlying supply, boiling does not remove these risks. Additional filtration specific to the contaminants present should be used, or consider distillation.

Unless your tap water has an EPA violation or “do not drink” notice, boiling should make it safe for consumption. But remember boiling is not a cure-all treatment.

When in doubt, have your water tested by a certified lab to identify any risks requiring additional treatment. Those with weakened immune systems or special medical needs may also wish to take extra precautions.

Safety Tips When Handling Boiled Water

When dealing with freshly boiled water, keep these safety tips in mind:

• Use caution when pouring boiled water to avoid scalds. Resist drinking it hot.

• Allow it to cool before transferring to bottles or pitchers. Vent releasing steam.

• Store properly – refrigerate in clean, enclosed bottles out of sunlight.

• Avoid contaminants – Use only food-grade glass, stainless steel, or ceramic. No plastic.

• Use by 1-2 days – For freshest quality and taste, use boiled water within 1-2 days.

• Discard if fouled – Throw out water if smells, tastes, or looks abnormal. Do not consume.

By taking appropriate precautions, you can safely handle boiled water and avoid recontamination risks.

Frequently Asked Questions

Let’s review some common boiling water questions when it comes to chlorine removal:

Q: Can boiling remove all chlorine from water?

A: Boiling removes 60-98% of chlorine, but trace residual may remain. Additional filtration is recommended if aiming for completely chlorine-free water.

Q: Can you boil chlorinated pool/hot tub water to make it drinkable?

A: No. Pool/spa water contains chlorination byproducts and other chemicals unsafe to ingest. Boiling cannot make pool or spa water potable.

Q: Does boiling water remove beneficial minerals like calcium and magnesium?

A: No. Boiling does not remove dissolved inorganic minerals – it can even concentrate them. Use distillation or ion exchange to remove minerals.

Q: Can boiled water be left unrefrigerated?

A: For food safety and to prevent microbial growth, boiled water is best stored refrigerated in a sealed container and used within 1-2 days.

Q: Does boiling tap water remove lead?

A: No. Boiling does not remove heavy metals like lead, arsenic, or mercury. Specialized filters are required to reduce these contaminants.

Q: Is it safe to use boiled chlorinated water for infant formula?

A: It’s best to start with water that meets FDA bottled water standards for infant formula preparation. Chlorine and other risks may remain in boiled tap water. Use purified water or consult your pediatrician.

Conclusion: Confidently Remove Chlorine by Boiling

Now that you understand the science behind boiling out chlorine, as well as guidelines for safe usage and storage, you can put this method into practice in your home.

Boiling tap water for 5-10 minutes can eliminate over 90% of chlorine. Paired with carbon filtration to “polish” the water, boiling provides an effective chlorine removal solution with minimal cost or fuss.

While it does not replace a full water purification system, boiling tap water remains a simple way to improve taste and remove chlorine odors. Follow the advice here to maximize chlorine reduction from boiling.

Implement this method to enjoy cleaner, fresher tasting water from your tap – just as nature intended it to be. Your health, cooking, and budget will thank you!