Chloroform in the Environment and its Dangers

Chloroform is famous for its ability to act as an anesthetic, but it is also toxic and can cause serious health problems. Unfortunately chloroform is widespread in the environment, but there are ways in which we can limit our exposure to the chemical.

Chloroform is also called trichloromethane and has the formula CHCl₃. It’s a clear and colorless liquid with a pleasant odor, and is nonflammable. The liquid tastes sweet but also produces a hot, burning sensation in the mouth and throat. Contact with liquid chloroform produces sores on the skin. Chloroform is a volatile substance – it easily changes from a liquid to a vapor at normal environmental temperatures. It is made in laboratories for industrial use and is also made naturally by certain seaweeds.

Inhaled chloroform vapor is an effective anesthetic because it depresses central nervous system activity. 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. James Young Simpson, a Scottish obstetrician and surgeon, popularized the use of chloroform for this purpose. In 1847 he discovered from personal experience that chloroform was an excellent anesthetic. He and some friends inhaled chloroform to discover its effects. They were all rendered unconscious, but luckily did not inhale enough of the vapor to kill themselves. Simpson was very impressed by the results of his experiment.

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.

Today scientists know that chloroform is not the wonder chemical that it first appeared to be. Inhaled chloroform can cause heartbeat irregularities that can be deadly. It can also cause liver and kidney damage, and high concentrations 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.

 Ultraviolet radiation from sunlight causes chloroform and oxygen to slowly react to form a gas called phosgene. This gas is poisonous, 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.

Chlorine is often added to drinking water and swimming pool water to kill bacteria and other microbes. Chloroform and other disinfection by-products form when the chlorine reacts with organic molecules in the 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 other disinfection by-products are absorbed though the skin, or enter the body if a person swallows water or breathes vapor coming from the water.

In homes, scientists have found that chlorinated water produces vapor containing chloroform, especially if the water is hot. The hotter the water, the higher the chloroform concentration in the air. Hot shower or bath water, hot cooking water and hot laundry or dish washing water can all raise the chloroform level. Chlorine used to clean toilets or to bleach clothes can also produce chloroform.

Certain industries release chloroform into the atmosphere. They use chloroform 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, however, 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 chloroform. Some foods contain chloroform because chlorinated tap water was used to produce them.

In the past, chloroform was added to some cough medicines, but in 1976 the United States banned this use. However, cough syrups in some countries still contain chloroform.

The effects of chloroform on our bodies depend on the concentration of the chloroform and the length of time that we are exposed to the chemical. There are several steps that we can take to reduce our exposure to chloroform. The use of water and shower filters that reduce the chlorine level in home water would be a big help, as would taking shorter showers and baths. Scientists have found that using less hot water in the home and/or opening windows to improve ventilation greatly reduces the level of chloroform in the air. Avoiding the use of cleaning products that contain chlorine is another step that could be taken to reduce chloroform exposure. Using other swimming pool disinfection methods instead of chlorine would also be very helpful, especially if someone is a frequent swimmer in the pool.