Fog Machine - Adverse Health Effects

Adverse Health Effects

Atmospheric effects generated using water and dry ice or liquid nitrogen can present asphyxiation or breathing hazards. Both carbon dioxide and nitrogen displace ordinary air and the oxygen it contains, creating a risk of subtle anoxia (lack of oxygenation) for people working in these atmospheres. Adequate ventilation is essential to ensure that artists and technicians are surrounded by breathable air. Carbon dioxide has the added hazard of interfering with the normal breathing reflex, which is sensitive to carbon dioxide levels in the air. Nitrogen has no effect on the breathing reflex, but this creates its own hazard in that a person breathing pure nitrogen can lose consciousness from lack of oxygen without any premonitory symptoms. Fog produced with liquid air does not present the hazards of carbon dioxide or liquid nitrogen because the liquid air has the same composition as ordinary atmospheric air (including the same level of breathable oxygen). Fog machines which generate their effects solely using water, such as ultrasonic or pressurized technology, pose no special health risks, however it should be noted that "water based" fog fluid does contain glycol. A number of studies have been published on the potential health effects presented by exposure to glycol based theatrical fogs and artificial mists. Two studies, a Health Hazard Evaluation completed in 1994 by the National Institute for Occupational Safety and Health, and another one in 2000 by the Department of Community and Preventative Medicine at the Mount Sinai School of Medicine and ENVIRON; both prepared for Actors Equity and the League of American Theaters and Producers, focused on the effects on actors and performers in Broadway musicals. The conclusion of both studies was that there was irritation of mucous membranes such as the eyes and the respiratory tract associated with extended peak exposure to theatrical fog. Exposure guidelines were outlined in the 2000 study that, it was determined, should prevent actors from suffering adverse impact to their health or vocal abilities. Another study focused on the use of theatrical fog in the commercial aviation industry for emergency training of staff in simulated fire conditions. This study also found eye and respiratory tract irritation. In May 2005, a study published in the American Journal of Industrial Medicine, conducted by the School of Environment and Health at the University of British Columbia, looked at adverse respiratory effects in crew members on a wide variety of entertainment venues ranging from live theaters, concerts, television and film productions to a video arcade. This study determined that cumulative exposure to mineral oil and glycol-based fogs were associated with acute and chronic adverse effects on respiratory health. This study found that short-term exposure to glycol fog was associated with coughing, dry throat, headaches, dizziness, drowsiness, and tiredness. This study also found long-term exposure to smoke and fog was associated with both short-term and long-term respiratory problems such as chest tightness and wheezing. Personnel working closest to the fog machines had reduced lung function results. The Entertainment Services and Technology Association (EST) has compiled a standard for theatrical fogs or artificial mists compositions for use in entertainment venues that "are not likely to be harmful to otherwise healthy performers, technicians, or audience members of normal working age, which is 18 to 64 years of age, inclusive." This standard was based primarily (though not exclusively), upon the findings of a report commissioned for EST by the Cohen Group and applies only those fog fluid compositions that consist of a mixture of water and glycol (so called "water based" fog fluid). Short term exposure to glycol fog can be associated with headaches, dizziness, drowsiness and tiredness. Long term exposure to smoke and fog can be related to upper airway and voice symptoms. Extended (multi-year) exposure to smoke and fog has been associated with both short-term and long-term respiratory health problems. Efforts should be made to reduce exposure to theatrical smoke to as low a level as possible. The use of digital effects in post production on film and television sets can be considered a safer practise than using theatrical smoke and fog during filming, although this is not always practical.