Does Boiling Water Remove Chlorine and Chloramine? (Australia 2026)

Why This Question Matters More in Australia Than Anywhere Else

Most English-language advice on boiling water and chlorine comes from the United States, where free chlorine is still the dominant disinfection method. In Australia, the landscape is inverted. Our five largest chloramine cities serve roughly 14.5 million people — over half the national population. The advice “just boil it” gets repeated constantly on Reddit, Facebook groups, and even by some plumbing shops. And for most Australians, it is wrong.

Understanding the chemistry behind this requires knowing exactly what your water utility puts into the water, how those chemicals behave when heated, and what alternatives actually work. That is what this article covers — in full, with measurements, references to the Australian Drinking Water Guidelines (ADWG), and practical solutions ranked by effectiveness.

Free Chlorine vs. Chloramine: The Chemistry That Changes Everything

Australian water utilities use two fundamentally different disinfection strategies. They are not interchangeable, and they respond to treatment — including boiling — in entirely different ways.

Free Chlorine (Cl₂ / HOCl)

Free chlorine is dissolved chlorine gas or hypochlorous acid. It is a volatile compound, meaning it wants to escape from water into the atmosphere. This is why a chlorinated swimming pool has that distinctive smell — chlorine is off-gassing constantly. Free chlorine’s boiling point is approximately −34°C, far below water’s 100°C. When you heat water, you accelerate the release of dissolved free chlorine. At a rolling boil, the agitation and elevated temperature drive it off rapidly.

Australian cities using free chlorine: Melbourne, Hobart, Canberra, Townsville, Cairns, Toowoomba.

The ADWG guideline value for chlorine is 5 mg/L, though most utilities target 0.5 to 1.5 mg/L at the tap. Melbourne Water typically delivers water with free chlorine residuals between 0.1 and 0.5 mg/L — among the lowest in any major Australian city, owing to its protected catchments in the Yarra Ranges.

Chloramine (NH₂Cl)

Chloramine is formed by combining chlorine with ammonia. The resulting monochloramine molecule is far more stable than free chlorine. It does not off-gas readily. It does not break down easily with heat. It was specifically chosen by utilities because of this stability — chloramine maintains a disinfection residual across long pipe networks (such as Brisbane’s SEQ grid, which spans from the Sunshine Coast to the Gold Coast) without degrading the way free chlorine does.

Australian cities using chloramine: Brisbane (SEQ Water Grid), Sydney (Sydney Water), Adelaide (SA Water), Perth (Water Corporation), Darwin (Power and Water Corporation).

Chloramine concentrations in these cities typically range from 1.5 to 4.0 mg/L at the tap. The ADWG guideline value for monochloramine is 3 mg/L.

What Happens When You Boil Chlorinated Water: The Science

Let’s walk through the mechanism step by step, because this is where most online advice goes wrong by conflating two very different processes.

Boiling and Free Chlorine

Free chlorine exists in water primarily as hypochlorous acid (HOCl) and hypochlorite ion (OCl⁻). Both are volatile dissolved gases at equilibrium. When water temperature rises:

1. Solubility decreases. Henry’s Law dictates that gas solubility in water decreases as temperature increases. At 100°C, the solubility of chlorine in water approaches zero.
2. Agitation accelerates release. A rolling boil creates vigorous convection and surface disruption, dramatically increasing the rate at which dissolved chlorine transfers from the liquid phase to the gas phase.
3. Time required: Research from the US EPA and municipal water studies indicates that 15 minutes of rolling boil reduces free chlorine concentrations from typical tap levels (0.5-2.0 mg/L) to below detectable limits (< 0.02 mg/L).

Verdict for free chlorine: Boiling works. If you live in Melbourne, Hobart, Canberra, Townsville, Cairns, or Toowoomba, boiling your water for 15-20 minutes will effectively remove the chlorine.

However — and this is critical — it is an absurdly energy-intensive way to do it. Running an electric kettle at 2,400W for 20 minutes costs roughly $0.16 per batch (at $0.30/kWh). A benchtop carbon block filter achieves the same result instantly, for a fraction of a cent per litre, with no energy input.

Boiling and Chloramine

Chloramine does not behave like free chlorine under heat. The nitrogen-chlorine bond in monochloramine (NH₂Cl) is covalent and considerably more stable than the loosely-held dissolved chlorine gas. Here is what actually happens:

1. Chloramine has extremely low volatility. Its Henry’s Law constant is orders of magnitude lower than that of free chlorine. It does not want to leave the water.
2. Thermal decomposition is slow. Chloramine begins to break down at elevated temperatures, but the rate is glacial compared to free chlorine off-gassing. Studies (including work by Valentine et al., published in Environmental Science & Technology) show that boiling chloraminated water for 20 minutes may reduce chloramine by only 30-50% from initial concentrations.
3. Decomposition products are problematic. When chloramine does break down at high temperatures, it can form ammonia and potentially dichloramine (NHCl₂) and nitrogen trichloride (NCl₃) — both of which are more toxic and more odorous than the original monochloramine.
4. Concentration effect. As water evaporates during prolonged boiling, the volume decreases. If chloramine is not being removed as fast as water is evaporating, the concentration of chloramine per litre can actually increase.

Verdict for chloramine: Boiling does not reliably remove chloramine. If you live in Brisbane, Sydney, Adelaide, Perth, or Darwin, boiling your water is not a solution for chloramine removal. You need a different approach.

The Full Comparison: Every Method for Removing Chlorine and Chloramine

Boiling is just one of several methods people use. Here is how they all stack up, with specific notes for Australian water chemistry.

What Boiling Does and Does Not Remove: The Complete Picture

Even if you do live in a free chlorine city and boiling technically works for chlorine, it is worth understanding what boiling does to the other contaminants in your water.

What boiling removes or reduces

• Bacteria, viruses, and protozoa — killed or inactivated at 100°C. This is the legitimate use case for boiling water (e.g., during a boil-water advisory from your utility).
• Free chlorine — off-gassed through volatility, as discussed above.
• Some volatile organic compounds (VOCs) — compounds with boiling points below 100°C may partially off-gas.

What boiling does NOT remove

• Chloramine — as covered in detail above.
• Fluoride — fluoride is a non-volatile ion. Boiling water does not remove fluoride. Worse, as water volume decreases through evaporation, fluoride concentration increases. If you start with 1 mg/L fluoride (the typical Australian dosing level per the ADWG) and boil off half the water, you end up with approximately 2 mg/L fluoride in the remaining water. Only reverse osmosis (90-97% removal) or activated alumina (80-95%) can remove fluoride from drinking water.
• Heavy metals — lead, copper, arsenic, and other dissolved metals are not volatile. Boiling concentrates them.
• PFAS (per- and polyfluoroalkyl substances) — these “forever chemicals” are thermally stable at 100°C (their molecular bonds do not break below approximately 400°C). Boiling does nothing. PFAS removal requires reverse osmosis or granular activated carbon (for longer-chain PFAS only). PFAS in Australian drinking water
• Nitrates — non-volatile. Concentrated by boiling.
• Total dissolved solids (TDS) — concentrated by boiling, not reduced.
• Microplastics — not removed by boiling. A 2024 study published in Environmental Science & Technology Letters actually found that boiling hard water can trap some microplastics in calcium carbonate precipitates, but this effect is inconsistent and not a reliable treatment method.

Your City, Your Disinfection Type: Quick Reference

Before you decide on any treatment method, you need to know what is in your water. Here is the definitive city-by-city breakdown for Australia.

The Decision Tree: What Should You Actually Do?

Forget boiling. Here is the logical process for choosing the right treatment for your Australian home.

5-Year Cost Comparison: Boiling vs. Filtration

Let’s put real numbers on this. Assume a household consuming 4 litres per day (1,460 litres per year) and electricity at $0.30/kWh (typical QLD/NSW retail rate in 2025-2026).

Note: Boiling is the cheapest per litre, but it only works in free chlorine cities, does not remove fluoride or PFAS, wastes 20 minutes per batch, and adds heat and humidity to your kitchen. The Tappwater EcoPro is cheaper than RO and handles chlorine and chloramine effectively, but will not remove fluoride. For comprehensive protection in any Australian city, RO is the standard.

Best countertop water filter for Australia

Common Myths About Boiling Water in Australia — Busted

Myth 1: “Boiling removes everything”

False. Boiling kills pathogens and removes volatile compounds like free chlorine. It does not remove fluoride, chloramine, heavy metals, PFAS, nitrates, or TDS. It concentrates non-volatile contaminants by reducing water volume.

Myth 2: “If I boil it long enough, chloramine will come out”

Technically, extended boiling (60+ minutes in an open vessel) may reduce chloramine concentrations significantly. But this is not practical. You would boil away most of your water, concentrate every other non-volatile contaminant, consume enormous amounts of energy, and still not achieve the removal efficiency of a $99 benchtop filter.

Myth 3: “My Brita filter handles chloramine”

Standard Brita jugs use granular activated carbon (GAC). GAC removes free chlorine effectively but removes chloramine at approximately 1/40th the rate. In a chloramine city like Brisbane or Sydney, a standard Brita jug will make a marginal difference to taste at best. You need catalytic carbon, a compressed carbon block rated for chloramine, or reverse osmosis. Do Brita filters work for Australian water?

Myth 4: “Leaving water in a jug overnight removes chloramine”

This works for free chlorine (off-gassing over 2-4 hours in an open container). It does not work for chloramine, which has a half-life of 50-100+ hours in open water at room temperature. You would need to leave a jug of Brisbane tap water sitting open for days to see meaningful chloramine reduction — and by then, you would have a bacterial contamination problem far worse than the chloramine you were trying to remove.

Myth 5: “Australian tap water does not need filtering — it meets ADWG guidelines”

The ADWG sets limits based on what is considered safe at a population health level. It does not mean you will enjoy the taste, nor does it mean there are zero contaminants. The ADWG guideline for chloramine is 3 mg/L — that is the maximum, not the target. And the ADWG does not set guideline values for PFAS (those fall under separate health advisories). “Meeting guidelines” and “optimised for drinking” are two different standards. Filtering is not a statement that your water is unsafe — it is a decision to set a higher bar for what goes into your body.

When Boiling IS the Right Call

I do not want to leave the impression that boiling water is never useful. There are specific scenarios where it is the correct action:

1. Boil-water advisories. When your water utility issues a boil-water notice (e.g., after a main break, flood event, or treatment plant failure), boiling for at least 1 minute at a rolling boil is the recommended response per ADWG and state health department guidance. This kills bacteria, viruses, and protozoa like Cryptosporidium and Giardia.
2. Emergency/disaster situations. If mains supply is compromised and you are relying on untreated surface water, boiling is the most accessible disinfection method.
3. Tank water without UV or chlorination. Rural and semi-rural Australians on rainwater tanks without treatment should boil water if there is any doubt about microbial safety — particularly after heavy rain that may have washed animal faecal matter into the collection system.
4. Travel in areas without treated water. If you are camping or travelling remote in Australia, boiling or a portable UV purifier (e.g., SteriPen) protects against waterborne pathogens.

In all of these cases, the purpose of boiling is pathogen kill, not chemical removal. That distinction is everything.

A Note on Shower Filters and Chloramine

While this article focuses on drinking water, I get asked about shower filters constantly — especially from people in Brisbane and Sydney who notice their skin and hair drying out. The same chemistry applies:

• Chloramine cities (Brisbane, Sydney, Adelaide, Perth, Darwin): Most shower filters use KDF-55 media, which works for free chlorine but is ineffective against chloramine. You need a vitamin C (ascorbic acid) shower filter or one with catalytic carbon media. KDF-55 shower filters are a waste of money in these cities.
• Free chlorine cities (Melbourne, Hobart, Canberra, etc.): KDF-55 and standard carbon shower filters work fine.

Best shower filter for Australian water

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Written by Jayce Love

Former Royal Australian Navy Clearance Diver and TAG-E counter-terrorism operator. Founded Clean and Native to apply the same rigorous thinking to the home environment.

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