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Chloroform in the Environment and Its Potential Health Dangers

Linda Crampton is a science writer who is interested in environmental issues. She is very concerned about the harmful effects of pollution.

Some seaweeds make chloroform, such as the kelp (a type of seaweed) behind the leopard shark.

Some seaweeds make chloroform, such as the kelp (a type of seaweed) behind the leopard shark.

An Environmental and a Health Problem

Chloroform is an interesting chemical. It's famous for its ability to act as an anesthetic and is useful in industry and science laboratories. Unfortunately, it’s a toxic substance and can cause serious health problems when it's sufficiently concentrated. These problems include organ damage and heartbeat irregularities. At high concentrations, inhalation of chloroform can depress the respiratory system so much that death occurs. The chemical is also strongly suspected of increasing the risk of cancer.

Chloroform is widespread in the environment and is made both naturally and artificially. Most people are exposed to low levels of the chemical, but some people—especially those working in certain industries—are exposed to higher levels. Fortunately, there are ways in which we can limit our exposure to the substance.

Chloroform has a relatively simple structural formula but can produce major effects.

Chloroform has a relatively simple structural formula but can produce major effects.

Properties of the Chemical

Chloroform is also called trichloromethane and has the formula CHCl3. At room temperature, it's a clear, colorless, and dense liquid that has a pleasant odor and is nonflammable. As the quote below says, however, the ability of people to detect the chemical varies. The substance tastes sweet but produces a hot, burning sensation in the mouth and throat. Contact with the liquid produces sores on the skin. The liquid form of chloroform is a volatile substance. This means that it has the tendency to change into a vapor at normal environmental temperatures.

Chloroform is made synthetically for industrial use and is produced naturally from chlorine in the environment. It's also made by some seaweeds and microalgae. Its non-medical applications are useful, but the chemical needs to treated with care when it's used in laboratories and industrial processes.

Odor thresholds vary greatly. Do not rely on odor alone to determine potentially hazardous exposures.

— New Jersey Department of Health (with respect to chloroform detection)

Photograph and signature of James Young Simpson (1811-1870), the Scottish surgeon who popularized the use of chloroform as an anesthetic

Photograph and signature of James Young Simpson (1811-1870), the Scottish surgeon who popularized the use of chloroform as an anesthetic

Discovery of Chloroform and Its Ability to Act as an Anesthetic

Chloroform was discovered in 1831 and 1832 by three different scientists working independently—an American doctor named Samuel Guthrie, a French chemist named Eugene Soubeiran, and a German chemist called Justus von Liebig.

A few years after its discovery, scientists realized that chloroform could act as an anesthetic. It causes a person to lose consciousness because it depresses central nervous system activity. The central nervous system consists of the brain and the spinal cord.

James Young Simpson, a Scottish obstetrician and surgeon, popularized the use of chloroform as an anesthetic. He discovered the chemical's abilities from personal experience. In 1847, Simpson and some friends deliberately inhaled chloroform to explore its effects. They were all rendered unconscious, but luckily they didn't inhale enough vapor to kill themselves. The experiment was potentially dangerous. Simpson was very impressed by the results of his investigation.

Chloroform quickly replaced ether as the anesthetic of choice, since unlike ether it didn’t have a strong and unpleasant smell, could be used in smaller quantities, started to work more quickly, and wasn’t flammable.

In chemistry, the word "ether" refers to a family of chemicals. Diethyl ether is the chemical name of the compound that was once used as an anesthetic.

Chloroform in Queen Victoria’s Life

Chloroform gained prominence when it was administered to Queen Victoria (1819–1901) in 1853 during the birth of Prince Leopold, her eighth child. She also inhaled the chemical in 1857 during the birth of Princess Beatrice, her ninth and final child. The administrator of the drug was Dr. John Snow. He used enough chloroform to relax his patients during childbirth but not enough to render them unconscious. This required a very careful calculation of dose.

Chloroform was found to be very effective as an anesthetic. However, one serious problem with its use in medicine is that it has a low margin of safety. This means that there is only a small difference between a dose that is helpful and a dose that is harmful. In addition, chloroform inhalation for the purpose of anesthesia produces a number of potentially dangerous side effects.

One potentially dangerous side effect of a chloroform anesthetic is the creation of heartbeat irregularities.

One potentially dangerous side effect of a chloroform anesthetic is the creation of heartbeat irregularities.

There are many ways for chloroform to enter the environment, so small amounts of it are likely to be found almost everywhere.

— ATSDR (Agency for Toxic Substances and Disease Registry)

Potential Health Dangers of Chloroform

Today scientists know that chloroform is not the wonder chemical that it first appeared to be. When it's inhaled, it can cause heartbeat irregularities that may be deadly. It can also cause liver and kidney damage. High concentrations of the chemical may produce headaches, dizziness, and gastrointestinal problems such as nausea and vomiting. In addition, chloroform has been classified as a probable carcinogen—a chemical that can cause cancer. Newer anesthetics have replaced chloroform in the operating room.

Chloroform is rapidly absorbed through both the respiratory tract and the gastrointestinal tract. It can also be absorbed through the skin. Once inside the body, it travels widely. Most of the chemical is eventually broken down or leaves the body by exhalation and excretion, but some may collect in body fat and organs.

Phosgene Formation, Uses, and Dangers

Chloroform can be dangerous without being absorbed. Ultraviolet radiation from sunlight causes chloroform and oxygen in the environment to slowly react, forming a gas called phosgene. This gas is more toxic than chloroform and is especially dangerous if it collects in an enclosed space and becomes concentrated. Phosgene was used as a chemical weapon in World War One. Its formula is COCl2 or CCl2O. Both formulas are considered to be correct.

Interestingly, phosgene is an important industrial chemical today. The CDC (Centers for Disease Control and Prevention) says that it's used to make plastics and pesticides. Anyone who has to deal with the chemical needs to take adequate precautions and be very careful. Phosgene is a strong irritant in both its gaseous and its liquid form. It damages tissues in the nose, throat, and lungs and causes choking. It also irritates the skin and eyes.

Even chemists working with chloroform need to be careful with the chemical. The video below discusses safety tips for dealing with chloroform and other substances in the laboratory.

Chlorinated Water Benefits and Disadvantages

Research has shown that the biggest contributor to chloroform in our bodies is chlorinated water. Chlorine is often added to drinking water and swimming pool water to kill bacteria and other microbes. Getting rid of the microbes is very important, but unfortunately using chlorine as a disinfectant can cause problems.

Chloroform and other disinfection by-products form when chlorine reacts with organic molecules in water. In swimming pools, these organic molecules can come from shed skin cells, sweat, urine, cosmetics, sunscreens, leaves, and soil, for example. Once they are formed, chloroform and the other disinfection by-products are absorbed though the skin or enter the body when a person swallows water or breathes vapor coming from the water.

Very hot water in dishwashers and washing machines can cause chloroform to vaporize from chlorinated water.

Very hot water in dishwashers and washing machines can cause chloroform to vaporize from chlorinated water.

Chloroform Production in Homes and Industry

Scientists have found that chlorinated water in homes produces vapor containing chloroform, especially if the water is hot. The hotter the water, the higher the concentration of the chemical in the air. Hot shower or bathwater, hot cooking water, and hot laundry or dish washing water can all increase the concentration of chloroform in a home. Chlorine used to clean toilets or to bleach clothes can have the same effect.

Certain industries release chloroform into the atmosphere. They use the chemical as a reactant in chemical reactions and as a solvent—a chemical that dissolves other substances. Chloroform is used in some countries to produce a refrigerant known as R-22. The use of R-22 is gradually decreasing, since it causes ozone depletion in the atmosphere. Chloroform is also released into the air from pulp and paper mills and from landfills and hazardous waste sites.

Chloroform enters our bodies when we drink chlorinated water and eat food containing the chemical. The chemical is present in some foods because chlorinated tap water was used to produce them.

In the past, chloroform was added to some cough medicines. In 1976, the United States banned this use of the chemical. Cough syrups in some countries may still contain the substance.

Hot, chlorinated water in showers releases chloroform.

Hot, chlorinated water in showers releases chloroform.

How to Reduce Chloroform Exposure

It's very likely that all of us absorb some chloroform from our environment. Though we probably don't need to be concerned about a small amount entering our bodies, it's a good idea to reduce the quantity when we can.

The effects of chloroform on our bodies depend on the concentration of the chemical and the length of time that we are exposed to it. There are several steps that we can take to reduce the absorption of the chemical. The last step in the list below may require the help of swimming pool officials.

  • Use water and shower filters that reduce the chlorine level in home water.
  • Take shorter showers and baths.
  • Use less hot water in the home.
  • Open windows to improve ventilation in areas where chloroform is likely to form.
  • Avoid the use of cleaning products that contain chlorine.
  • If you could be exposed to chloroform while you're doing a job at home or at work, make sure that you follow all of the recommended safety precautions.
  • Use other swimming pool disinfection methods instead of chlorine. This step is especially important for someone who is a frequent swimmer in a pool.

Maintaining a Safe Environment

Most of us don't need to worry excessively about the amount of chloroform that we absorb. It is a good idea to be aware of the potential dangers, however. People working in jobs where chloroform is made or used or those living near a facility that releases it into the environment need to be careful. The risk of ill effects is highest for these people. Chloroform is an intriguing chemical to explore and has some interesting properties, but the potential problems that it can cause should be taken seriously.


This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.

Questions & Answers

Question: How does well water that has been tested with a high level of chloroform affect the body?

Answer: The potential effects of chloroform in water depend on its concentration. Since you’ve discovered that the water in your well contains a high level of the chemical, you should contact your local public health department or some other department in your local management or government organization. They will likely ask about the specific concentration of the chemical discovered in the test and then give you recommendations about what to do next. It’s important that you do this so that you know whether it’s safe to use the water.

Question: How does the chemical Chloroform affect the environment?

Answer: Researchers say that at its usual environmental concentration chloroform is unlikely to harm the environment significantly. These facts may not be true if the level of chloroform is increased due to some type of accident or another event, however. There are concerns that a high concentration of the molecule might harm some aquatic organisms. Also, it might react with other types of air pollution to form ground-level ozone, which can damage crops, though researchers seem to disagree about this possibility.

© 2010 Linda Crampton


Linda Crampton (author) from British Columbia, Canada on November 07, 2018:

I suggest that you contact the person or department responsible for safety at your lab to talk to them about the situation if you haven’t already done so. You should also look at the Material Safety Data Sheet for chloroform. (It does list nausea as a possible symptom of exposure.) If your symptoms continue you should seek medical help. It’s probably a good idea to wash your sweater separately from the rest of your clothes.

Sileena Cherukuri on November 07, 2018:

Can chloroform make you nauseous and light-headed? I spilled a couple drops of chloroform on my sweater in my research lab but didn't think it was a big deal until I felt nauseous all of a sudden half an hour later, around lunch time. Also can I wash my sweater normally or should I isolate it from my other clothes?

Linda Crampton (author) from British Columbia, Canada on November 02, 2018:

You would have to contact your local government or a local environmental consultant to find out whether this is possible in your well and how it could be done effectively and safely if it is possible.

I do wonder how the chloroform got in the well water. Perhaps you or someone else adding chlorine to the water in order to kill coliform bacteria. If this was the case, you need to get advice from a public health official to make sure that the bacteria have disappeared and to safely prevent them from appearing again.

Rizwan khaleel on November 02, 2018:

How to clear out increased amount of of chloroform in wells ?

Linda Crampton (author) from British Columbia, Canada on August 11, 2016:

Thanks for the comment, Matthew.

Matthew on August 11, 2016:

It was very helpful Thank you

Linda Crampton (author) from British Columbia, Canada on April 29, 2012:

I'm not a doctor, Urgent, and I can't help you, but a doctor could! GET MEDICAL HELP!! A doctor will be able to find out what the problem is and treat it. Go to a doctor's office, a clinic or a medical center ASAP and explain the situation to the people there. You need to find out why your chest feels heavy when you've been asleep.

Urgent!!!!! ASAP on April 29, 2012:

You are going to think I am crazy and it is sending me insane, I think my partner and or his friend is using chloroform on me to make me sleep? I am confused so distressed and I need someone's help please help me, will it feel as tho my chest is heavy and caving in if I have been exposed to it in my sleep? And I need to no how I get tested or if I can get tested to see wether it is in u system please do not ignore this question I need your help please some one give me answers?

Linda Crampton (author) from British Columbia, Canada on November 13, 2011:

Hi, hubler. Thanks a lot for the comment. I'm wondering why anyone would want to make chloroform, though. My hub was trying to point out the dangers of chloroform and how to avoid it in the environment - it's not a safe chemical!!! If you look at the "Dangers" paragraph in the hub you'll see that chloroform can sometimes be deadly. We should all be trying to avoid chloroform, not make it!

hubler on November 13, 2011:

So i wanted to make chloroform. Then i looked at this. And now im much more informed, and i know so much more! Im probably not going to, but im very happy i read this well writen hub (i think that's what it is, im new to this).

Linda Crampton (author) from British Columbia, Canada on March 12, 2011:

Thank you very much, BkCreative! Yes, it does seem that we are using certain chemicals without properly understanding their effects on people and the environment.

BkCreative from Brooklyn, New York City on March 12, 2011:

Good grief! It just freaks me out how toxic chemicals are just put out there into the environment, well because it does a particular job - but wait? How does it affect humans and other animals? No clue. Perhaps we are all not meant to swim in a pool filled with chlorine. Ugh.

I wrote a hub about the filth in community pools and to address the human filth - what is done? More chlorine is added to the water. We lose all around.

Great informative article by the way. I've learned quite a bit. Your hubs are super. Thanks and rated up!

Linda Crampton (author) from British Columbia, Canada on December 01, 2010:

Hi Nell. Thanks for the rating. It’s actually scary to know what we’re exposed to in the environment every day.

Nell Rose from England on December 01, 2010:

Hi, this was fascinating, I never knew most of this, especially the mixing in the air, etc and to know that it can get into your skin and body when in a swimming pool, wow, great information, rated up cheers nell

Linda Crampton (author) from British Columbia, Canada on November 14, 2010:

Thank you, Kdban101. This was an interesting hub to create.

Kdban101 on November 14, 2010:

good and informative hub.