Chlorine Exposure


Chlorine exposure occurs when a person encounters unsafe levels of the chemical chlorine. This can take place through eating or drinking chlorine-contaminated food or drink, physical contact with chlorine, or breathing in chlorine gas.


Chlorine is a gas that at room temperature has a yellow-green color and a strong smell much like bleach. Chlorine is used for many purposes, such as in the sanitation of sewage and industrial waste, in cleaning products, and in the production of chlorides, pesticides, synthetic rubbers, and refrigerants. Exposure to unsafe levels of chlorine in any form is a serious health threat.

In sewage and water, chlorine is used as part of the sanitation process. In the United States, the limit for chlorine in water is four parts per million (ppm). At this level, chlorine can reduce the spread of bacterial diseases but is still safe for human consumption. Drinking water that contains more than four ppm on a regular basis can cause serious health problems.

Chlorine is also used in many cleaning solvents and in industry. For example, chlorine may be used to bleach wood pulp, purify metals, and to make other chemicals, pesticides, synthetic rubbers, and refrigerants. Working with chlorine allows it to escape into the air. The United States Occupational Safety and Health Administration (OSHA) limits exposure to chlorine in the workplace to one part per million (ppm) at any given time. The American Conference of Governmental Industrial Hygienists and the National Institute for Occupational Safety and Health suggest that the limit should be 0.5 ppm for a forty-hour workweek, and only as high as one ppm when exposure will be under fifteen minutes. Exposure to chlorine gas at higher levels or for a time may cause both temporary and permanent health complications.

Causes and symptoms

Symptoms of chlorine exposure depend heavily on the type and concentration of exposure. Short-term exposure to high levels (30 ppm) of chlorine in the air has been shown to cause difficulty breathing, chest pain, vomiting, and excess fluid in the lungs (pulmonary edema). Lower levels (15 ppm) can cause nose and throat irritation, and levels as low as 3–6 ppm may irritate the eyes. Exposure to chlorine in the air at 430 ppm for just 30 minutes is known to cause death. Drinking chlorine at levels over four ppm may cause nausea, vomiting, and throat and stomach irritation. Higher concentrations may cause burning of the esophagus, blood in stools, and severe abdominal pain. Skin contact with chlorine will cause irritation and may result in frostbite burns of the skin or eyes. Exposure to chlorine in the eyes can cause permanent damage including blindness.

Long-term and low-level exposure to chlorine is also a health threat. After several years of low-level exposure, teeth can decay, and lung disease may develop. This is especially a problem in people who already have a lung disease or who smoke. As of 2012, there was no concrete data on whether long-term chlorine exposure causes cancer or affects reproduction in humans or animals.

The muscular tube that leads from the back of the throat to the stomach. Coated with mucus and surrounded by muscles, it pushes food to the stomach by contraction.
Frostbite burn—
Destruction of a specific area of skin and other body tissue due to direct contact with a certain chemical, such as chlorine or liquid nitrogen.
Pulmonary edema—
Fluid accumulation in the lungs; it is frequently a complication of heart disease and other medical disorders.


A person who has been exposed to unsafe levels of chlorine in the air should move to a chlorine-free open space as quickly as possible. There is no treatment for chlorine exposure directly; however, symptoms that persist can be treated. People who experience severe irritations, coughing, difficulty breathing, or pulmonary edema may need hospital care.

Clothes that may have chlorine on them should be removed quickly and, when possible, cut off to avoid spreading chlorine onto a person's face or other body parts. The clothing should be put in a sealed bag to reduce the likelihood of additional exposure. Chlorine should be washed off of the skin with large amounts of soap and water. Eyes that have been exposed to chlorine should be flushed with large quantities of water for a long period (at least 15 minutes). Contact lenses that have been exposed to chlorine should be thrown away. Medical treatment may be needed even if the chlorine was only on the skin for a short time.

A person who has swallowed chlorine should be given water or milk immediately, unless they are experiencing symptoms that make it difficult to swallow, for this may cause the person to choke. Unless directed to by medical personal or poison control, the person should not be forced to vomit. Medical attention should be sought as quickly as possible.




Good safety measures are the best prevention against chlorine exposure. This includes using proper storage and spill management if a chlorine spill does exist. Respirators should be used when working in areas with unsafe concentrations of chlorine in the air. Protective clothing and equipment should also be used when working with liquid chlorine. This may include goggles or a face shield. Exposure limitation levels set by the OSHA should be followed to protect workers.

Individuals can protect themselves from chlorine exposure by not regularly drinking water with a level higher than four ppm and by carefully managing household cleaning agents. Household cleaners should not be mixed without understanding what may happen. For example, household bleach should never be mixed with acid-containing or ammonia-containing cleaning products. This can release harmful gases that are a serious health threat. Chlorine has a strong smell and people should show caution when able to smell chlorine in the air.

See also National Institute for Occupational Safety and Health ; Occupational Safety and Health Administration ; Sanitation .



Chemical Hazards Emergency Medical Management. “Chlorine—Emergency Department/Hospital Management.” (accessed October 19, 2012).

MedlinePlus. “Chlorine Poisoning.” (accessed October 19, 2012).

New York State Department of Health. “Facts About Chlorine.” (accessed October 19, 2012).

Occupational Safety & Health Administration. “Occupational Safety and Health Guidelines for Chlorine.” (accessed October 19, 2012).


Agency for Toxic Substances and Disease Registry, 4770 Buford Hwy. NE, Atlanta, GA, 30341, (800) 232-4636; TTY: (888) 232-6348,, .

United States Centers for Disease Control and Prevention (CDC), 1600 Clifton Road, Atlanta, GA, 30333, (404) 639-3534, (800) CDC-INFO (800-232-4636); TTY: (888) 232-6348,, .

United States Department of Labor Occupational Safety & Health Administration, 200 Constitution Avenue, Washington, DC, 20210, (800) 321-OSHA (6742); TTY: 877-889-5627, .

Tish Davidson, AM

  This information is not a tool for self-diagnosis or a substitute for professional care.