For centuries, boiling water has been the go-to method for making water safer to drink. Even now, when there are concerns about an outbreak of waterborne contaminants in Australian tap water, the advice given by state governments and water utilities is typically to boil water before consumption.
However, while boiling is effective for killing bacteria and viruses, not all contaminants can be removed or neutralised by heat. In fact, some impurities may even become more concentrated as water evaporates during the boiling process.
This article takes a closer look at what boiling does to your water, which contaminants and impurities can survive the process, and how you can protect your home and family from the most stubborn and stable contaminants.
What Does Boiling Water Do?
Boiling water is a simple and effective way to kill bacteria, viruses, and parasites that might be present in untreated or contaminated water. If you’ve ever had to boil water due to a temporary water quality alert, it was likely to protect against microbial risks.
Bacteria and microbial issues can be difficult to deal with through filtration, so boiling is the best way to neutralise them. Heating water to its boiling point (100 degrees celsius) does not completely sterilise the water, but the heat does cause structural damage to living organisms, killing and neutralising bacteria and waterborne pathogens.
Heat can also trigger chemical reactions in certain chemicals, causing them to evaporate along with the water. This can be difficult with more stable chemical compounds or substances with higher boiling points, but volatile organic compounds (VOCs) typically evaporate easily.
However, while boiling can eliminate harmful microorganisms, it does not remove many other contaminants, such as chemicals, heavy metals, or dissolved solids. These substances remain in the water even after extended boiling.
Contaminants That Boiling Water Won’t Remove
1. Heavy Metals (Lead, Copper, Mercury, etc.)
Heavy metals can leach into drinking water from old pipes, industrial pollution, or natural sources. Common heavy metals found in water include lead, copper, arsenic, and mercury.
Why Boiling Doesn’t Help:
- Heavy metals have a significantly higher boiling point than water, so they will not evaporate at boiling temperatures.
- Boiling water can actually increase metal concentration as water evaporates and contaminants are left behind.
2. Chloramine
Chloramine is a chlorine-ammonia compound used in several regions across Australia as a disinfectant, just like chlorine. Bonding with ammonia makes the particle more stable, allowing it to continue protecting water through longer pipes and in higher temperatures that would cause chlorine to dissipate before the water reaches people’s homes.
Why Boiling Doesn’t Help:
- While chlorine can be boiled away in around 15 minutes, chloramine is more stable and remains in your water.
- Harmful chloramine byproducts, such as trihalomethanes (THMs), are often more volatile and will boil away easily. However, this actually increases exposure; studies have found that people absorb more THMs from hand-washing dishes and showering in hot water than from drinking contaminated water.
3. Fluoride
Fluoride is added to most Australian tap water supplies in line with public health initiatives to prevent tooth decay. While widely supported by health authorities, some people prefer to reduce their fluoride intake.
Why Boiling Doesn’t Help:
- Like salt in seawater, fluoride is a dissolved mineral that does not break down or evaporate with heat.
- As with heavy metals, boiling fluoridated water slightly increases fluoride concentration.
4. Pesticides and Agricultural Chemicals
Runoff from farms and agricultural areas can introduce pesticides and herbicides into water supplies. While Australia has strict water safety standards, trace amounts of chemicals like glyphosate (found in weed killers) and atrazine (a common pesticide) can still be present in drinking water.
Why Boiling Doesn’t Help:
- Many pesticides and herbicides are heat-resistant and remain in water even after boiling.
- Increasing the concentration of these chemicals through water evaporation can elevate them to potentially harmful levels.
5. Nitrates & Nitrites
Nitrates and nitrites come from agricultural runoff, fertilisers, and even sewage contamination. These contaminants are a concern because high nitrate levels in drinking water have been linked to health risks, particularly for infants.
Why Boiling Doesn’t Help:
- Nitrates are highly soluble and do not break down with heat.
- Nitrate and nitrite exposure have been linked to elevated risks of gastric cancer, so increasing the concentration through boiling is counterproductive.
6. Microplastics and Sediments
Microplastics—tiny plastic particles from pollution, synthetic clothing, and industrial waste—have been found in drinking water worldwide, including in Australia.
Why Boiling Doesn’t Help:
- While larger plastic debris can melt, microplastic particles do not break down in boiling water.
- Boiling can make microplastic particles bond with minerals in hard water, but those particles will remain suspended in your water unless it goes through further filtration.
7. Pharmaceuticals and Hormones
Traces of pharmaceuticals, including hormones, antibiotics, and painkillers, have been detected in water supplies around the world. While Australian water treatment facilities work to keep contamination low, trace amounts can still enter drinking water through wastewater systems.
Why Boiling Doesn’t Help:
- Many pharmaceutical compounds are heat-stable and do not break down at boiling temperatures.
- Boiling water does not remove synthetic hormones (such as those found in birth control pills), which can affect human and environmental health.
How Can You Remove These Contaminants?
Since boiling water won’t remove these impurities, what are the best ways to ensure clean drinking water?
1. Reverse Osmosis (RO) Filtration
Reverse osmosis is one of the most effective ways to remove a wide range of contaminants, including fluoride, heavy metals, pesticides, and nitrates.
- Removes up to 99% of dissolved impurities
- Reduces heavy metals, chlorine, fluoride, and chemical contaminants
- Provides clean, purified water for drinking and cooking
2. Carbon Filters (GAC/CC)
Activated and catalytic carbon filters are highly effective for reducing chlorine, chloramine, and some organic chemicals.
- Great for improving taste and smell
- Reduces chlorine and some volatile organic compounds (VOCs)
- Often used in combination with other filtration methods
3. Whole-Home Water Filtration Systems
A whole-home water filter can help remove contaminants before they reach your taps, protecting both drinking and bathing water. These systems often incorporate carbon filters with other dedicated media for sediments, heavy metals, and dissolved minerals.
- Removes chlorine and sediments from every tap
- Helps protect skin from irritation caused by chemicals in water
- Provides additional protection against VOCs and THMs that are absorbed through your skin and lungs
- Ensures cleaner, safer water throughout your home
Final Thoughts: Boiling Alone Isn’t Enough
While boiling water is great for killing bacteria and viruses, it does not remove many of the common contaminants found in Australian tap water. Heavy metals, chlorine, fluoride, and other impurities require advanced filtration methods to be effectively removed.
At Complete Home Filtration, we provide high-quality water filtration solutions to ensure your household has access to safe, clean water—without the impurities that boiling can’t remove.
If you’re concerned about what’s in your tap water, book a free in-home water test with one of our expert technicians today. We’ll help you understand what’s in your water and recommend the best filtration system for your home.
To get started, send us a message below or call 1300 693 458.
