Chemical pneumonitis

Chemical pneumonitis is an inflammation of the lungs (pneumonitis) or breathing difficulty caused by inhalation of noxious chemicals.

Causes, incidence, and risk factors

Many household and industrial chemicals are capable of producing both an acute and a chronic form of inflammation in the lung. Acute chemical pneumonitis causes swelling of the lung tissue, movement of fluid into the air spaces in the lung, and less ability to absorb oxygen and get rid of carbon dioxide. In severe cases, death may result from lack of oxygen reaching the tissues (hypoxia).

Chlorine gas is one of the most irritating commonly inhaled substance. Exposure to dangerous levels of chlorine gas may occur at home (during use of cleaning materials such as chlorine bleach), in industrial accidents, or near swimming pools. Inhalation of dangerous substances can occur in many different settings, including factories (especially during smelting, welding, or other metal work), the production or use of solvents or pesticides, fires (house fires, wildfires), and the handling of grain.

Chronic chemical pneumonitis can follow low levels of exposure to the lung irritant over extended periods of time. This causes inflammation and may provoke fibrosis (scarring) with decreased oxygen exchange and stiffening of the lung. Unchecked, this condition may ultimately lead to respiratory failure and death.


  • unusual sensation (possibly burning feeling) in the chest  
  • difficulty breathing  
  • air hunger  
  • cough  
  • possibly wet or gurgle sounding breathing (abnormal lung sounds)


  • shortness of breath with only mild exercise  
  • rapid breathing (tachypnea)  
  • cough may or may not occur  
  • progressive disability (related to shortness of breath)

Signs and tests
The following tests help determine how severely the lungs are affected:

  • X-ray of the chest  
  • blood gas  
  • lung function studies

Treatment is focused on reducing symptoms. Oxygen therapy may be helpful. Corticosteroids may be given to reduce inflammation.

Expectations (prognosis)
The outcome depends on the chemical agent involved, the severity of exposure, and whether the problem is acute or chronic.

Respiratory failure and death can occur.

Calling your health care provider
Call your health care provider if you have trouble breathing after inhaling (or possibly inhaling) any substance.

Household chemicals should be used only as directed and always in well-ventilated areas. Work rules regarding breathing masks should be followed and the appropriate breathing mask should be worn. Persons who work near fires should take care to limit exposure to smoke or gases.

Johns Hopkins patient information

Last revised: December 3, 2012
by Levon Ter-Markosyan, D.M.D.

Medical Encyclopedia

  A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | 0-9

All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.