Chlorine in Drinking Water: The Good, the Bad, and the Ugly
Updated November 30th, 2022
Chlorine is by far the most commonly used water disinfectant worldwide. Today, about 98% of U.S. municipalities use some chlorine-related process to treat their drinking water, thanks to the chemical’s wide-scale availability, low cost, ease of use, and proficiency at destroying germs.
When chlorine is added to your water supply, it rapidly reduces the spread of all kinds of waterborne diseases, like cholera and typhoid fever, as well as other ailments. It also makes it easier for cities and towns to purify drinking water to keep residents (like yourself) safe. But like all good things in life, this highly effective and inexpensive disinfectant comes with a price.
Researchers have linked chlorine in drinking water to incidences of bladder, rectal, and breast cancer. Also, a report from the U.S. Council of Environmental Quality states that people who drink chlorinated water are up to 93% more likely to get cancer than those whose water does not contain chlorine. (We’ll elaborate on this later.)
While we recognize and applaud the handful of amazing benefits chlorine has brought us, we must strive to protect ourselves from any possible dangers it might present. Let’s start by looking at the chemistry behind chlorine then pick up from there.
What is Chlorine?
Chlorine (CI) is a naturally-occurring chemical element that exists as a toxic, irritant, and poisonous greenish-yellow gas at room temperature. It can be pressurized and cooled then converted to a liquid form. When the liquid chlorine is released, it quickly turns into a gas that stays close to the ground and spreads rapidly.
Chlorine is a vital element that serves many different purposes. Perhaps its most popular application is to disinfect drinking water and treat standing water (for example, pool water). If you’ve ever been to a water park or often swam in chlorinated pools, you are probably aware of the distinctive smell of chlorine.
You don’t even have to leave your home to notice the presence of chlorine in the water, though. The chemical can be found in nearly all tap water in the United States. It is also a widely known component in sodium chloride, the regular table salt that we use to cook, bake, enhance tastes, and preserve food. Chlorine also plays a crucial role in manufacturing medicines, PVC pipes, plastics, bumpers, seat cushions, and many other products.
What does chlorine contain?
Chlorine, in its raw, natural form, is a gas that is toxic to your health if you inhale it. Although chlorine is a chemical, it is not synthetically composed of multiple components. In other words, it is just an element.
The chlorine gas itself is not usually used for things like pool treatment. Instead, liquid chlorine or sodium hypochlorite (NaOCl) is added to the pool water. When either of these forms of chlorine is pumped into the water, it creates hypochlorous acid (HOCl), which is highly active against all bacterial, viral, and fungal human pathogens. A small amount of HOCl can kill spore-forming and non-spore bacteria in a short time.
For drinking water, the water providers add chlorine (Cl2) or hypochlorite to the water at the treatment plant. There, they pressurize the chlorine gas to convert it to a liquid. When it dissolves in the water, the chlorine converts to hypochlorous and hydrochloric acid (HCl).
Why is chlorine added to drinking water?
The high toxicity of chlorine makes it a powerful chemical that can destroy bacteria, microbes, and pathogens that can leach into your water supply. By killing these disease-causing germs, the compound helps to make water safe to drink.
Waterborne diseases have killed thousands of U.S. residents every year. Thankfully, chlorine in public water systems has helped to virtually eliminate the risk for many treacherous waterborne diseases, such as cholera, typhoid fever, dysentery, salmonella, and many others.
Besides, chlorine has played a significant role in increasing the life expectancy of Americans by 50 percent during the 20th century. For this and other reasons, the U.S. Centers for Disease Control and Prevention (CDC) lauds drinking water chlorination as “one of the most significant health advances in U.S. history.”
In addition to killing dangerous germs like bacteria, viruses, and parasites, chlorine also helps reduce offensive tastes and odors in water. Furthermore, the chemical helps to eliminate molds, slime, algae, and bacteria that grow in water supply reservoirs, storage tanks, and on the walls of water mains.
Consequently, the U.S. Environmental Protection Agency requires that water providers add a detectable level of chlorine in their water to help protect against pathogens as the water flows from the treatment plant to the consumers’ homes.
How effective is chlorine against waterborne germs?
Chlorine is highly effective against most pathogens found in various water sources. However, the ability of the chemical to destroy germs depends on the amount of chlorine in the water, and the amount of contact time between the compound and the microorganisms.
Under the right circumstances, chlorine can quickly kill most waterborne germs, but there is a few exceptions. Microorganisms, such as Cryptosporidium, are resistant to regular chlorination practices. Because of this, some water systems may require additional treatment processes to protect against these and other particularly resistant pathogens.
How does chlorine destroy waterborne germs?
Chlorine destroys waterborne germs by penetrating their slime coatings, resistant shells, and cell walls. The chemical either kills the bacteria or disrupt their DNA so that they cannot reproduce.
So, how much chlorine is added to my water supply?
It’s difficult to say how much chlorine is in your water exactly. The fastest way to find out is to either request a water quality report from your local municipality or purchase a DIY home water test kit and check your water for chlorine.
A water quality report usually contains vital, detailed information regarding the chlorine concentration in your area’s drinking water. Some water providers often publish their water reports online.
A DIY home water test kit can help you determine the amount of chlorine in your water supply in under 10 minutes. There are many different testing kits available online from various merchants, so you can shop around and compare each kit to get the best bang for your buck.
Springwell offers two different testing kits, one with just a water check option and the other with a water check with pesticides option. Both testing kits check your water for 75 various contaminants, including:
- Bacteria (presence/absence of coliform and E. coli)
- (15) Heavy metals and minerals
- (5) Other inorganic chemicals
- (5) Physical characteristics
- (4) Trihalomethanes (THM’s)
- (44) Volatile organic compounds (VOC’s)
The CDC suggests that chlorine levels of up to 4 milligrams per liter (mg/L) or four parts per million (ppm) are considered safe for human consumption. The World Health Organization (WHO), however, estimates that most water treated with chlorine contains the chemical at a concentration between 0.2 and 1 ppm.
But still, with the vast number of treatment facilities in the U.S. and the wide variety of treatment practices they use, you should not assume that the amount of chlorine in your drinking water is necessarily close to these measurements.
If you live in a highly-populated area with water sources that must undergo treatment before being distributed to residents, chances are the chlorine level of the outgoing water is tested every day. However, if you reside in a rural area with a relatively lower population, the chlorination level of your local water supply is likely checked once a month. In this case, you should purchase a Springwell Water Check Testing Kit to get a precise reading of the level of chlorine in your water.
What are the health effects of chlorine?
When added to water, chlorine does a darn good job of protecting us from various bacteria and other disease-causing microorganisms in water. However, in recent years, there have been several concerns regarding the safety of adding such a toxic chemical to drinking water.
The main problem with chlorine is that when it is added to your drinking water, it naturally reacts with the organic compounds that are already present in the water. Therefore, the chlorine will create disinfection byproducts, or DBPs for short. The most toxic DBPs created by chlorine are trihalomethanes (THMs).
Research shows that consuming water with THMs or inhaling them can lead to several serious health complications, such as stillbirths, congenital disabilities, increased risk of kidney and liver cancer, and issues with the central nervous system, heart, kidneys, and liver.
Inhaling THMs and chlorine can be more dangerous than consuming them because both chemicals convert into vapor at a lower temperature than water. That means taking a shower in chlorinated water can increase your exposure to these toxic chemicals.
And when we think it couldn’t get any worse, a 2005 academic article stated that THMs are more concentrated in the body when absorbed through the skin than drinking tap water that contains the chemicals. These toxic DBPs don’t only affect your health when you drink tap water but might be a significant risk every time you take a shower.
The effects of chlorine on your hair and skin
Long-term exposure to chlorine can ultimately ruin the quality of your skin and hair. If you often swim in or shower with chlorinated water, your skin and hair may become dry, itchy, and flaky. Your skin may even turn red when it is touched, and your hair may feel frizzy and dry. Chlorine can also cause hair color to fade faster than usual if you dye your hair.
Moreover, if you have sensitive or delicate skin or hair, you are particularly vulnerable to the harsh effects of chlorine exposure. This is because the human body naturally produces proteins and oils that form a thin protective coating around your skin and hair.
This layer ensures that your epidermis stays healthy, soft, and well protected. But unfortunately, chlorinated water can wash away this layer and exposure your hair and skin to vicious water contaminants and the elements, causing extreme dryness and irritation.
How chlorine damages your gut
An alarming concern about chlorine stems from the very reason why it’s so useful – its ability to destroy bacteria. When chlorine is added to water, it kills disease-causing bacteria. But when it is introduced into the human body, it destroys our vital gut bacteria, where about 70% of our immune processes operate.
According to recent research, healthy and flourishing gut bacteria help the body to function correctly. Sadly, scientists have found a connection between a lack of these valuable microns in our digestive system and the presence of a broad range of diseases – including type 2 diabetes, obesity, irritable bowel syndrome, colorectal cancer, and certain autoimmune diseases, such as asthma, diabetes, and autism. Poor gut health can even lead to other conditions, such as bloating, gas, abdominal pain, constipation, and diarrhea.
How to protect yourself and your family from the toxic effects of chlorine in drinking water
There are several different ways to protect yourself and your family from the harsh effects of chlorine in drinking water. Of course, some of these methods are more practical or inexpensive than others.
Choosing the right approach depends on how much chlorine is present in your tap water, and of course, your budget. While you think about those factors, here are five treatment methods for chlorine, as well as their pros and cons:
1. Filtration (Our Recommendation)
Our recommended approach to treating chlorinated water is filtration. By running the water through a filter with activated charcoal in granular or particle form, you can significantly reduce the chlorine and chloramine contents in your water, as well as the general taste and odor associated with chlorine and DBPs.
Carbon filtration technology is not new. It has come a long way and has gotten a lot better since ancient days when the Egyptians stored water in charcoal because they discovered that the water was fresher and tasted better when stored there.
The most popular type of carbon filter we have today is the activated carbon filter. This type of filter uses granular activated carbon media to effectively reduce and filter out various classes of contaminants and unwanted agents in your water. Although less common than an activated carbon filter, the catalytic activated carbon filter is a more advanced form of carbon filtration.
We use carbon filtration in most of our water filtration systems because catalytic activated carbon is highly effective at removing chlorine, THMs, and chloramines from water through a process known as adsorption.
Adsorption basically “soaks up” particles like a sponge to water. It then adheres the particles to a surface (like a piece of Velcro). Organic compounds bond or stick to the surface of the carbon filter because water and contaminants attract each other.
Carbon filters are incredibly porous and usually have a large surface area. These features make them more effective at reducing bad tastes, odors, and other particles in water. The filter acts as an ice tray with pores for the ice slots for contaminants as water flows through it.
The tiny pores are measured in microns. The smaller the micron, the better the filtration. Factors like pressure and low flow rate allow the contaminants more time to “form ice” or adhere to the carbon. The more contact time the water has with the surface of the carbon filter, the more efficient the filtration.
Inside our carbon filters is coconut shell carbon, which is the most renewable among other types of filter media like bituminous coal and wood-based media. Coconut shell carbon is made from the shell of a coconut, so it doesn’t cause allergic reactions or flavored water. ,Bituminous coal is not used as widely today since traces of arsenic have been discovered in the media. Wood-based carbon is made from the burned wood ground into a granule that looks similar to what the ancient Egyptians would have used.
|– Commercially available||– Might be relatively expensive|
|– Highly effective||– Installation required|
|– Hands-free/Automated operation||– Not all filters will remove chloramine.|
|– Can soften water|
2. Ultraviolet (UV) radiation
UV radiation is also an effective method of water purification, though it is not as widely used as water filtration. You can use UV light to dechlorinate your water as it’s effective against chlorine and chloramine. Plus, it doesn’t have the drawbacks of chemical treatment or filtration.
The good thing about using UV radiation is that because chlorine is light-sensitive, the UV rays can break down and destroy traces of it. The longer chlorine is exposed to the UV light, the more it dissipates.
The main disadvantage of UV lights, however, is that they aren’t available from your grocery store. They often cost a lot of money to acquire, and continued exposure isn’t healthy for your skin.
|– Doesn’t affect the taste of the water||– Exposure to UV radiation can be dangerous.|
|– Eliminates both chlorine and chloramine||– Not easily accessible|
|– No chemicals required||– Can be pricey|
One might argue that the simplest and most cost-effective way to remove chlorine from water is to let the water sit for some time so that the chlorine in the glass or pitcher will evaporate.
While this “standing” method sounds good and all, it has some drawbacks. Firstly, it’s not an immediate solution to your chlorine problem. You’ll need to exercise patience as it could take very long for the chlorine to evaporate. Even so, letting the tap run for a while is not likely to remove any sizable portion of chlorine, unless you were to let the water sit overnight before consuming it.
Your environment will play a massive role in how quickly the chlorine evaporates. Chlorine is gas at room temperature, so the warmer the air, the faster it will disperse. Heck, it could have already formed a deadly byproduct. That means you will need another form of neutralization or removal process.
|– Costs nothing||– Not an instant solution|
|– No tools or installation required.||– Ineffective against chloramine byproduct|
|– Little to no effort required|
|– Natural solution|
4. Boiling your water
If the any of the methods above doesn’t spark your interest, then you could use the most basic process of water purification: boiling your water. As we mentioned earlier, the chlorine will evaporate faster in warmer air. The warmer the environment, the faster the chlorine disperses.
However, the fact is, boiling the water will only remove some amount of chlorine in the water, not all of it. Should you proceed with this method, the San Francisco Public Utilities Commission (SFPUC) recommends that you boil the water for about 20 minutes to remove chloramine and ammonia from your tap water effectively. Regrettably, there was no substantial evidence that boiling removes chlorine.
Nevertheless, the boiling method is a small price to pay since it doesn’t require adding chemicals or purchasing and setting up equipment.
|– Little to no effort required||– Higher energy bills|
|– No equipment or installation required.||– It doesn’t remove chlorine entirely.|
|– No impact on taste|
5. Chemical purification
As absurd as this might sound, treating chlorinated water with chemicals is a legitimate purification method. The workings of this method might be a bit complicated for some people, especially those who dislike anything that relates to the subject of chemistry.
But for those chemistry-lovers, the best chemical treatment for chlorine in drinking water is potassium metabisulfite (K-meta). When one of these K-meta tablets dissolves into chlorinated water, it neutralizes the chlorine, then evaporates.
What’s also remarkable about K-meta is that it is powerful enough to remove both chlorine and chloramine. Beyond that, one K-meta tablet can dechlorinate up to 20 gallons of water!
|– Cheap||– Limited availability|
|– Works against both chloramine||– Carries a stifling smell|
The Best Chlorine Water Filters
Since our recommended method to dechlorinate water is through filtration, it’s only right that we tell you about the best chlorine water filters to help you achieve the best results. Many different options combine activated carbon filters with other filtration technologies to combat chlorine and other related chemicals in your water supply, but these particular models lead the pack.
CF1 4-Stage Whole House Filtration System: The CF1 is a top-tier, durable, and highly efficient point-of-entry (POE) water filtration system that can accommodate large dwellings without taking up a lot of space.
POE systems like the CF1 are usually installed at the main service line. That way, they can filter all the water entering your plumbing line before being transported to your faucets, pipes, and water-using appliances.
Impressively, the CF1 is robust and eliminates 99% of harmful contaminants from your water. These pollutants include chlorine, chloramine, PFOA, PFOS, pesticides, herbicides, haloacetic acids, and many more.
Moreover, the FF1 uses ActivFlo technology to filter your water through four critical stages, which includes an activated carbon filtration stage. The system filters your water by using coconut shell filtration media, and by allowing enough contact time between each step of the filtration process and the specific contaminants.
Furthermore, installation and set-up are easy. Plus, it requires little maintenance to upkeep its remarkable performance, and you won’t experience any drop in water pressure while using it. That’s because it has a jaw-dropping flow rate of 9 GPM for a 1 – 3-bathroom unit while the CF4 (the bigger sibling) offers 12 GPM for a 4 – 6-bathroom unit. But if you need a more robust solution, the CF+ system produces a whopping 20 GPM for a 7+ bathroom unit!
If you purchase any one of the three filtering systems and it does not meet your expectations (which is highly unlikely), there’s a six-month money-back guarantee that will allow you to return it and get your money back. Additionally, each system is covered with a manufacturer’s lifetime warranty against defects throughout its lifespan under regular application, service, and use.
SWRO-Nickel and SWRO-Bronze Countertop Reverse Osmosis Systems: Reverse osmosis is one of the most effective forms of home water filtration available. This filtration method removes more than 1000 pollutants from water.
The SWRO-Nickel or the SWRO-Bronze might be the most economical option for families living in smaller apartments or condos where countertop space is limited. These water filtering systems use reverse osmosis to remove all kinds of contaminants, thus producing pure, high-quality drinking water.
Both filters are compact point-of-use (POU) filters that fit neatly under your kitchen sink and provide 75 gallons of filtered water per day. They’re both perfect solutions for filtering out contaminants from your water, such as lead, mercury, fluoride, arsenic, aluminum, iron, chlorine, chloramine, herbicides, pesticides, chlorine byproducts, and more.
Maintenance is effortless, plus you also get the same warranty and money-back guarantee that come with the CF1.
If you want to ensure that your water is free of chlorine, chloramine, and other pollutants that love to plague your precious water, invest in either the CF1 whole house system or any one of the under-counter reverse osmosis systems.
Chlorine has been a much-loved disinfectant in the U.S. for years, mainly because of its cost-effectiveness, ease of use, wide-scale availability, and proficiency at destroying most pathogens that cause some of the most dangerous waterborne illnesses today. But even with its long list of invaluable benefits, there are some concerns about its adverse health effects. Research have proven that the chemical may lead to certain health complications like cancer, skin and hair irritations, congenital disabilities, stillbirths, liver and kidney issues, and many more. Thankfully, you can remove chlorine from your water through boiling, chemical purification, UV radiation, evaporation, and water filtration, our suggested treatment method.
If you’re ready to eliminate chlorine, DBPs, and many other pollutants from your drinking water, check out the CF1 4-Stage Whole-House Filtration System or the SWRO-Nickel and SWRO-Bronze Countertop Reverse Osmosis Systems to get started!