Uses, Benefits, and Safety of Chlorine | Chemical Safety Facts


Updated June 9, 2022

The filtration of drinking water plus the use of chlorine is probably the most significant public health advance of the millennium. – LIFE Magazine

Chlorine’s disinfection properties have helped improve the lives of billions of people around the world. Chlorine also is an essential chemical building block, used to make many products that contribute to public health and safety, advanced technology, nutrition, security and transportation. Food, water and medicines, computers and cell phones all depend on chlorine chemistry. Chlorine chemistry also is used in the manufacture of numerous products ranging from contact lenses, air conditioning refrigerants and solar panels, to bullet-resistant vests, energy-efficient windows, paint and prosthetics.

Chlorine is generally produced from ordinary salt – one of the most abundant, essential minerals on earth. The chlorine production process is efficient: hydrogen, a byproduct of the production process, is used as an energy source in many manufacturing facilities; and sodium hydroxide, another byproduct, is a valuable and essential product used to manufacture many consumer and industrial products.

Uses & Benefits

Chlorine chemistry helps keep families healthy and improves our environment:


Chlorine chemistry helps keep drinking water and swimming pools safe. Before cities began routinely treating drinking water with chlorine-based disinfectants, thousands died every year from waterborne diseases such as cholera, typhoid fever, dysentery and hepatitis A. Chlorine-based pool and spa disinfectants such as dichlor1 and trichlor2 help keep recreational waters safe by destroying waterborne pathogens that can result in illnesses, such as diarrhea, swimmer’s ear or skin rashes, including athlete’s foot.

Household Disinfectant

Chlorine chemistry is used to manufacture household chlorine bleach, which can whiten and disinfect clothes and disinfect kitchen and bathroom surfaces. Diluted bleach and water solutions are especially effective at killing germs that may be found on household surfaces that make people sick, including the norovirus (also known as the “stomach bug”) and seasonal flu.


Chlorine chemistry helps provide safe and abundant food by protecting crops from pests and keeping kitchen counters and other food-contact surfaces disinfected, destroying E. coli, salmonella and a host of other foodborne germs.


Chlorine chemistry is critical to manufacturing medicines we depend on, including some that can help lower cholesterol, control arthritis pain and relieve allergy symptoms. The products of chlorine chemistry can also be found in blood bags, medical devices and surgical stitches. Chlorine chemistry is also used to manufacture contact lenses, safety glasses and respiratory inhalers.

Energy and Environment

Chlorine chemistry plays an important role in harnessing solar energy, purifying the silicon in grains of sand and helping transform them into solar panel chips. Wind turbine blades made from chlorine-based epoxy resins help convert wind power into electricity.

Advanced Technology

Chlorine chemistry is used to manufacture fast processors that power smart phones, tablets, and computers. Chlorine chemistry is also used to manufacture residential and commercial air conditioning refrigerants, hybrid car batteries and high-performance magnets.

Building and Construction

Plastic foam insulation, manufactured using chlorine chemistry, can increase the energy efficiency of home heating and air-conditioning systems, reduce energy bills and help conserve natural resources. Energy-efficient vinyl windows can reduce heating and cooling costs and GHG emissions. Research indicates manufacturing vinyl windows requires approximately one-third of the energy needed to manufacture aluminum windows. And chlorine chemistry can even contribute to the beauty of every room in your home, as it is used to help manufacture durable paints.

Defense and Law Enforcement

Chlorine chemistry is used to manufacture bullet-resistant vests worn by soldiers and police officers. Chlorine chemistry is also used to produce parachutes and night vision goggles as well as cockpit canopies and missile guidance technologies.


Chlorine chemistry is used on planes, trains, automobiles, and boats, in the manufacture of seat cushions, bumpers, brake fluid and airbags that help keep passengers safe and comfortable. Chlorine chemistry is also used to manufacture shatter-resistant windows, wire and cable, steel hulls, and navigation systems.

Safety Information

Chlorine chemistry helps families lead safer, more convenient, more comfortable lives.

Chlorine is one of approximately 100 natural chemical elements, and naturally occurring chlorine compounds are found all over the world. Due to its chemical reactivity, chlorine is rarely present in nature by itself as elemental chlorine, and typically exists bonded to other elements in the form of chemical compounds such as sodium chloride (table salt).

Chlorine is not sold as a consumer product itself, but is used to manufacture consumer and industrial products, and may or may not be present in the finished consumer product. For example, titanium metal, used for everything from bicycles to artificial knee replacements, is purified using chlorine chemistry. Swimming pools use chlorine-based disinfectants, and chlorine is also essential in the manufacture of vinyl, which has an array of consumer and industrial applications.

Pool Chemical Safety

When used properly, chlorine-based disinfectants help protect swimmers from bacteria and other germs that can cause problems like swimmer’s ear or diarrhea. According to the Centers for Disease Control and Prevention (CDC), chlorine and pH are the first line of defense against germs that can make swimmers sick.

Basic safety tips for people who use pool chemicals include: wear protective gear; store chemicals in ventilated areas; do not store liquids – which can leak – directly above dry chemicals; and do not accidentally mix chemicals with each other or water. This pool chemical safety video contains important tips for handling and storing pool chemicals.

Chlorine Bleach Safety

When handled properly, according to manufacturers’ directions, chlorine bleach is not only safe, but it also helps keep people healthy by killing harmful germs on surfaces. However, when chlorine bleach is misused – for example, mixed with ammonia or acids – the result can be harmful to your health. Mixing chlorine bleach and ammonia generates toxic vapors. If you accidentally become exposed to fumes from mixing bleach and ammonia, immediately remove yourself from the vicinity to fresh air and seek emergency medical attention. The vapors can attack your eyes and mucous membranes, but the biggest threat comes from inhaling the gases. Call 911 for emergency help. If you don’t need emergency assistance, call Poison Control (1-800-222-1222) for advice on handling the after-effects of exposure and cleaning up the chemicals.

Answering Questions

What is chlorine?

Chlorine is a chemical element, one of roughly 90 basic building blocks of matter. Chlorine’s tendency to combine with other elements and compounds has been used to produce thousands of essential products, from drinking water disinfectants to solar energy panels to replacement knee and hip joints. Due to its chemical reactivity, chlorine is rarely present in nature by itself as elemental chlorine, and typically exists bonded to other elements in the form of chemical compounds such as sodium chloride (table salt).

Why is chlorine added to drinking water?

Chlorine destroys disease-causing germs and helps make water safe to drink. Waterborne diseases once killed thousands of U.S. residents every year. Following its first use in Jersey City, New Jersey in 1908, drinking water chlorination spread rapidly throughout the United States, and helped to virtually eliminate waterborne diseases like cholera and typhoid fever.3

Drinking water chlorination played a major role in increasing Americans’ life expectancy by 50 percent during the 20th century. The U.S. Centers for Disease Control and Prevention calls drinking water chlorination “one of the most significant public health advances in U.S. history.”

Besides killing dangerous germs like bacteria, viruses and parasites, chlorine helps reduce disagreeable tastes and odors in water. Chlorine also helps eliminate slime bacteria, molds and algae that commonly grow in water supply reservoirs, on the walls of water mains and in storage tanks. In fact, EPA requires treated tap water to contain a detectable level of chlorine to help protect against germs all the way to consumers’ taps.

Is chlorine in drinking water safe?

The small amount of chlorine added to disinfect drinking water in accordance with EPA regulations is safe for consumption. According to EPA, allowable chlorine levels in drinking water (up to 4 parts per million) pose “no known or expected health risk [including] an adequate margin of safety” while providing for “control of pathogens under a variety of conditions.”

Is using bleach or other chlorine disinfectants bad for the environment?

Handled properly, consumers can safely use bleach without significant environmental effects. As it reacts with germs and stains, between 95 and 98 percent of chlorine bleach breaks down and turns back into salt water. Importantly, waste- water treatment facilities use chlorine disinfectants to destroy oxygen-robbing contaminants in wastewater, helping to preserve the quality of our nation’s rivers and streams into which the treated wastewater is discharged.

For more information:

Chlorine Facts – Chlorine The Element of Surprise

Water Quality Fact Sheets – Pool & Hot Tub Alliance (



1Sodium Dichloro-S-Triazinetrione Fact Sheet (

2Trichloro-S-Triazinetrione Fact Sheets (

3Water Disinfection with Chlorine and Chloramine | Public Water Systems | Drinking Water | Healthy Water | CDC