In movies, theater productions and concerts you may have seen smoke that was used for effect or to help heighten the visual impact of lighting effects. This smoke is created by special fog machines, and it is not made of water vapor. Theater smoke consists primarily of a compound known as glycol. Glycol is found in substances such as vehicle anti-freeze, and can be harmful if ingested or inhaled by people. That leads to the a questioning of the potential effects of fog machine vapors.
Irritation
According to a 2000 study done by the Mount Sinai School of Medicine, theater fog containing glycol can irritate the membranes in the lungs and throat. This makes it painful to breathe and speak. The study suggested limits for exposure to theater smoke for actors and crew that are being used today.
Eyes
Glycol in a fog form can create irritation and dryness in the eyes that can make it very difficult to see. It also creates excessive tearing which can also impair the vision.
Lung Capacity
Exposure to theater smoke can inhibit the ability of the lungs to properly expand and retain oxygen. As the fog gets into the lungs, it irritates the lining of the lungs making deep breaths painful. This can be especially damaging to opera singers who rely on the ability to retain large reserves of air in their lungs to be able to perform.
Chest and Cough
The irritation cause by theater fog can also help to create a tight feeling in the chest. This is sometimes accompanied by a cough that, when added to the chest pain, can become painful.
Dizziness
According to AbsoluteAstronomy.com some of the other suspected side-effects of exposure to theater fog are dizziness, a shortness of breath, chronic headaches and chronic fatigue. As the glycol affects the body's ability to take in air, the body begins to run low on oxygen. When the body is low in oxygen, it begins to run down and experience these kinds of symptoms.