Chemical pneumonitis is inflammation of the lungs or breathing difficulty due to inhaling chemical fumes or breathing in and choking on certain chemicals.

Many household and industrial chemicals are capable of producing both an acute and a chronic form of inflammation in the lungs.

Some of the most common dangerous, inhaled substances include:

• Chlorine gas (during use of cleaning materials such as chlorine bleach, in industrial accidents, or near swimming pools)
• Grain and fertilizer dust
• Noxious fumes from pesticides
• Smoke (from house fires and wildfires)

Chronic chemical pneumonitis can occur after only low levels of exposure to the irritant over extended periods of time. This causes inflammation and may lead to stiffness of the lungs, which decreases the ability of the lungs to get oxygen to the body. Unchecked, this condition may ultimately lead to respiratory failure and death.

Chronic aspiration of acid from the stomach and exposure to chemical warfare can also lead to chemical pneumonitis.

Acute:

• Air hunger (feeling that you cannot get enough air)
• Cough
• Difficulty breathing
• Possibly wet or gurgle sounding breathing (abnormal lung sounds)
• Unusual sensation (possibly burning feeling) in the chest

Chronic:

• Cough may or may not occur
• Progressive disability (related to shortness of breath)
• Rapid breathing (tachypnea)
• Shortness of breath with only mild exercise

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

• Blood gas
• CT scan of chest
• Lung function studies
• X-ray of the chest
• Swallowing studies

Treatment is focused on reversing the cause of inflammation and reducing symptoms. Corticosteroids may be given to reduce inflammation, especially before long-term scarring occurs.

Antibiotics are usually not helpful or needed. Oxygen therapy may be helpful.

In cases of swallowing and stomach problems, eating small meals in the upright position can help.

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.

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. Never mix ammonia and bleach together.

Work rules regarding breathing masks should be followed and the appropriate breathing mask should be worn. People who work near fire should take care to limit exposure to smoke or gases.

Be careful about giving mineral oil to anyone who might choke on it (children or the elderly).

Don't siphon gas or kerosene.

Blanc PD. Acute pulmonary responses to toxic exposures. In: Mason RJ, Broaddus CV, Martin TR, et al. Murray & Nadel's Textbook of Respiratory Medicine. 5th ed. Philadelphia, Pa: Saunders Elsevier; 2010:chap68.

Christiani DC. Physical and chemical injuries of the lungs. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 94.