Theatrical smoke and fog
Encyclopedia
Theatrical smoke and fog, also known as special effect smoke, fog or haze, is a category of atmospheric effects used in the entertainment industry. The use of fog can be found throughout motion picture and television productions, live theatre, concerts, at nightclubs and raves, amusement and theme parks and even in video arcades and similar venues. These atmospheric effects are used for creating special effects, to make lighting and lighting effects visible, and to create a specific sense of mood or atmosphere. If an individual is at an entertainment venue and beams of light are visible cutting across the room, that most likely means smoke or fog is being used. Theatrical smoke and fog are indispensable in creating visible mid-air laser effects to entertain audiences. Recently smaller, cheaper fog machines have become available to the general public, and fog effects are becoming more common in residential applications, from small house parties to Halloween
and Christmas.
Theatrical fog and theatrical fog machines are also becoming more prevalent in industrial applications outside of the entertainment industry, due to their ease of use, inherent portability and ruggedness. Common popular applications for theatrical fog in include environmental testing, such as HVAC
inspections, as well as emergency personnel and disaster response training exercises.
Militaries have historically used smoke and fog to mask troop movements in training and combat, and the techniques and technology used for generating smoke and fog in theatre and film are similar.
or HVAC
smoke pencils or pens.
Smoke is differentiated from other atmospheric effects in that it is composed of solid particles released during combustion, rather than the liquid droplets that fog or haze are composed of.
Fog is created by pumping one of a variety of different glycol or glycol/water mixtures (referred to as fog fluid) into a heat exchanger (essentially a block of metal with a resistance heating element in it) and heating until the fluid vapourizes, creating a thick translucent or opaque
cloud. Devices specifically manufactured for this purpose are referred to as a fog machines.
An obsolete method for creating theatrical fog on-stage (although the technique is still commonly used in motion pictures) is to use a device known as a thermal fogger, initially designed for distributing pesticide, which aspirates a petroleum product (typically kerosene
or propane
) ignites the fuel, and then mixes in air and pesticide to create a dense fog. For theatrical purposes the pesticide is typically replaced with glycol, glycol/water mixtures, or water. This technique is similar to the smoke generators used by militaries to create smoke screens, and is generally only used outdoors due to the volume of fog produced and the petroleum fuel required.
"Low lying" fog effects can be created by combining a fog machine with another device designed specifically for this purpose. As the fog exits the fog machine it is chilled, either by passing through a device containing a fan and ice, or by passing through a device containing a fan and compressor
similar to an air conditioner. The result is a relatively thick fog that stays within a few feet of the ground. As the fog warms, or is agitated, it rises and dissipates. Several manufacturers of theatrical fog fluid have developed specially formulated mixtures specifically designed to be used with , intended to provide thicker, more consistent fog effects. Although these chilling devices do not use carbon dioxide, the specially formulated fog fluid does create denser fog than regular fog fluids.
Haze effects refer to creating an unobtrusive, homogeneous
cloud intended primarily to reveal lighting beams, such as the classic "light fingers" in a rock concert. This effect is produced using a haze machine
, typically done in one of two ways. One technique uses mineral oil
, atomized via a spray pump powered either by electricity or compressed CO2, breaking the mineral oil into a fine mist. Another technique for creating haze uses a glycol/water mixture to create haze in a process nearly identical to that for creating fog effects. In either case the fluid used is referred to as haze fluid, but the different formulations are not compatible or interchangeable. Glycol/water haze fluid is sometimes referred to as "water based haze" for the purposes of disambiguation.
Smaller volumes of haze can also be generated from aerosol
canisters containing mineral oil under pressure. Although to the density of haze generated and the volume of space that can be filled is significantly smaller than that of a haze machine, aerosol canisters have the advantages of portability, no requirements for electricity and finer control over the volume of haze generated.
Liquid carbon dioxide
(CO2), stored in compressed cylinders, is used in conjunction with theatrical fog machines to produce "low lying" fog effects. When liquid CO2 is used to chill theatrical fog, the result is a thick fog that stays within a few feet of the ground. As the fog warms, or is agitated, it rises and dissipates. Several manufacturers of theatrical fog fluid have developed specially formulated mixtures specifically designed to be used with CO2, intended to provide thicker, more consistent fog effects. Effect duration is determined by the heating cycle of the theatrical fog machine and consumption rate of liquid CO2.
Carbon dioxide can also be used as an atmospheric effect on its own. When liquid CO2 is released into the air, typically through an electric solenoid valve
to control timing and duration, the carbon dioxide liquid expands to a vapour and condenses
the moisture in the air, creating large billowing plumes. When the solenoid valve is closed, the CO2 vapour rapidly disperses in the air, ending the effect nearly instantaneously. This effect can be used for a variety of applications, including simulating geysers of steam, in place of pyrotechnics
, or to create an instant opaque wall for a reveal or disappearance during magic acts.
Dry ice
(solid carbon dioxide) effects are produced by heating water to or near boiling in a suitable container (for example: a 55 gallon drum with water heater coils in it), and then dropping in one or more pieces of dry ice. Because carbon dioxide cannot exist as a liquid at atmospheric pressure, the dry ice sublimates and instantly produces a gas, condensing water vapour and creating a thick white fog. A fan placed at the top of the container directs the fog where it is needed, creating a rolling fog that lies low to the ground. As the submerged dry ice cools the water, the amount and duration of fog produced will be reduced, requiring "rest" periods to reheat the water.
Dry ice can also be used in conjunction with a fog machine to create a low lying fog effect. Dry ice is placed inside an insulated container with an orifice at each end. Fog from a fog machine is pumped in one side of the container, and allowed to flow out the other end. Although this technique does allow an individual to create low lying fog "on the cheap" (when compared to the cost of renting cylinders of liquid CO2 or watertight containers with integral heaters), the volume of low lying fog produced is typically less, and is more susceptible to atmospheric disturbances.
(N2) is used to create low lying fog effects in a manner similar to dry ice. A machine heats water to at or near the boiling point, creating steam and increasing the humidity in a closed container. When liquid nitrogen is pumped into the container, the moisture rapidly condenses, creating a thick white fog. A fan placed at the output of the container directs the fog where it is needed, creating a rolling fog that lies low to the ground. These types of machines are commonly referred to as "dry foggers" because the fog created by this method consists solely of water droplets, and as it dissipates there is little to no residue left on any surfaces. Dry Fogger is also a trademarked name for a particular brand of this style of fog machine.
(1598–1613) reportedly used smoke effects during performances for atmosphere and special effects.
The operating characteristics of this compact, well-engineered and remote-controllable package make possible a range of safe special effects that would be totally impractical with larger, more conventional fog units.
is heavier than, and displaces, air and as such can present a serious hazard
. Unsafe concentrations of carbon dioxide will initially cause headache
s, nausea
, blurred vision
, dizziness
and shortness of breath. Higher concentrations will result in loss of consciousness and death
due to suffocation
. When using compressed carbon dioxide or dry ice
, care should be taken to ensure there is sufficient ventilation
available at all times, and that procedures are in place to rapidly evacuate CO2 from any enclosed space in an emergency.
Liquid carbon dioxide (−56.6 °C) and dry ice (−78.5 °C) present a significant risk of frostbite
if mishandled. Proper protective clothing, such as long sleeves and glove
s, should always be worn when handling these products. Liquid carbon dioxide, stored in compressed cylinders, also presents all the hazards attendant to materials under pressure and should be handled accordingly.
The first study that was completed was done by Consultech Engineering, Co. under contract to Actor's Equity. The findings of the Consultech study were confirmed by two additional 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 Theatres and Producers, focused on the effects on actors and performers in Broadway
musicals. The conclusion of all three 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 stimulated 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 theatres, 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
(ESTA) 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 ESTA 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.
Halloween
Hallowe'en , also known as Halloween or All Hallows' Eve, is a yearly holiday observed around the world on October 31, the night before All Saints' Day...
and Christmas.
Theatrical fog and theatrical fog machines are also becoming more prevalent in industrial applications outside of the entertainment industry, due to their ease of use, inherent portability and ruggedness. Common popular applications for theatrical fog in include environmental testing, such as HVAC
HVAC
HVAC refers to technology of indoor or automotive environmental comfort. HVAC system design is a major subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer...
inspections, as well as emergency personnel and disaster response training exercises.
Militaries have historically used smoke and fog to mask troop movements in training and combat, and the techniques and technology used for generating smoke and fog in theatre and film are similar.
Types of effects
There are generally 4 types of fog effects used in entertainment applications: Smoke, Fog, Haze, and "low lying" effects.Smoke
Smoke effects refers to theatrical atmospheric effects produced either by pyrotechnic materials, such as Smoke Cookies, and pre-fabricated smoke cartridges; or other, flammable substances such as incenseIncense
Incense is composed of aromatic biotic materials, which release fragrant smoke when burned. The term "incense" refers to the substance itself, rather than to the odor that it produces. It is used in religious ceremonies, ritual purification, aromatherapy, meditation, for creating a mood, and for...
or HVAC
HVAC
HVAC refers to technology of indoor or automotive environmental comfort. HVAC system design is a major subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer...
smoke pencils or pens.
Smoke is differentiated from other atmospheric effects in that it is composed of solid particles released during combustion, rather than the liquid droplets that fog or haze are composed of.
Fog
Opacity (optics)
Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation, especially visible light. In radiative transfer, it describes the absorption and scattering of radiation in a medium, such as a plasma, dielectric, shielding material, glass, etc...
cloud. Devices specifically manufactured for this purpose are referred to as a fog machines.
An obsolete method for creating theatrical fog on-stage (although the technique is still commonly used in motion pictures) is to use a device known as a thermal fogger, initially designed for distributing pesticide, which aspirates a petroleum product (typically kerosene
Kerosene
Kerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin or paraffin oil in the United Kingdom, Hong Kong, Ireland and South Africa, is a combustible hydrocarbon liquid. The name is derived from Greek keros...
or propane
Propane
Propane is a three-carbon alkane with the molecular formula , normally a gas, but compressible to a transportable liquid. A by-product of natural gas processing and petroleum refining, it is commonly used as a fuel for engines, oxy-gas torches, barbecues, portable stoves, and residential central...
) ignites the fuel, and then mixes in air and pesticide to create a dense fog. For theatrical purposes the pesticide is typically replaced with glycol, glycol/water mixtures, or water. This technique is similar to the smoke generators used by militaries to create smoke screens, and is generally only used outdoors due to the volume of fog produced and the petroleum fuel required.
Gas compressor
A gas compressor is a mechanical device that increases the pressure of a gas by reducing its volume.Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe. As gases are compressible, the compressor also reduces the volume of a gas...
similar to an air conditioner. The result is a relatively thick fog that stays within a few feet of the ground. As the fog warms, or is agitated, it rises and dissipates. Several manufacturers of theatrical fog fluid have developed specially formulated mixtures specifically designed to be used with , intended to provide thicker, more consistent fog effects. Although these chilling devices do not use carbon dioxide, the specially formulated fog fluid does create denser fog than regular fog fluids.
Haze
Homogeneous (chemistry)
A substance that is uniform in composition is a definition of homogeneous. This is in contrast to a substance that is heterogeneous.The definition of homogeneous strongly depends on the context used. In Chemistry, a homogeneous suspension of material means that when dividing the volume in half, the...
cloud intended primarily to reveal lighting beams, such as the classic "light fingers" in a rock concert. This effect is produced using a haze machine
Haze machine
Haze machines, or haze generators , are effects machines similar to fog machines, designed to produce an unobtrusive, homogeneous clouds suspended in the air intended primarily to make light beams visible or create a subtle diffusion.-Properties:Unlike theatrical fog, which is typically intended to...
, typically done in one of two ways. One technique uses mineral oil
Mineral oil
A mineral oil is any of various colorless, odorless, light mixtures of alkanes in the C15 to C40 range from a non-vegetable source, particularly a distillate of petroleum....
, atomized via a spray pump powered either by electricity or compressed CO2, breaking the mineral oil into a fine mist. Another technique for creating haze uses a glycol/water mixture to create haze in a process nearly identical to that for creating fog effects. In either case the fluid used is referred to as haze fluid, but the different formulations are not compatible or interchangeable. Glycol/water haze fluid is sometimes referred to as "water based haze" for the purposes of disambiguation.
Smaller volumes of haze can also be generated from aerosol
Aerosol
Technically, an aerosol is a suspension of fine solid particles or liquid droplets in a gas. Examples are clouds, and air pollution such as smog and smoke. In general conversation, aerosol usually refers to an aerosol spray can or the output of such a can...
canisters containing mineral oil under pressure. Although to the density of haze generated and the volume of space that can be filled is significantly smaller than that of a haze machine, aerosol canisters have the advantages of portability, no requirements for electricity and finer control over the volume of haze generated.
Carbon dioxide and dry ice
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
(CO2), stored in compressed cylinders, is used in conjunction with theatrical fog machines to produce "low lying" fog effects. When liquid CO2 is used to chill theatrical fog, the result is a thick fog that stays within a few feet of the ground. As the fog warms, or is agitated, it rises and dissipates. Several manufacturers of theatrical fog fluid have developed specially formulated mixtures specifically designed to be used with CO2, intended to provide thicker, more consistent fog effects. Effect duration is determined by the heating cycle of the theatrical fog machine and consumption rate of liquid CO2.
Carbon dioxide can also be used as an atmospheric effect on its own. When liquid CO2 is released into the air, typically through an electric solenoid valve
Solenoid valve
A solenoid valve is an electromechanical valve for use with liquid or gas. The valve is controlled by an electric current through a solenoid: in the case of a two-port valve the flow is switched on or off; in the case of a three-port valve, the outflow is switched between the two outlet ports...
to control timing and duration, the carbon dioxide liquid expands to a vapour and condenses
Condensation
Condensation is the change of the physical state of matter from gaseous phase into liquid phase, and is the reverse of vaporization. When the transition happens from the gaseous phase into the solid phase directly, the change is called deposition....
the moisture in the air, creating large billowing plumes. When the solenoid valve is closed, the CO2 vapour rapidly disperses in the air, ending the effect nearly instantaneously. This effect can be used for a variety of applications, including simulating geysers of steam, in place of pyrotechnics
Pyrotechnics
Pyrotechnics is the science of using materials capable of undergoing self-contained and self-sustained exothermic chemical reactions for the production of heat, light, gas, smoke and/or sound...
, or to create an instant opaque wall for a reveal or disappearance during magic acts.
Dry ice
Dry ice, sometimes referred to as "Cardice" or as "card ice" , is the solid form of carbon dioxide. It is used primarily as a cooling agent. Its advantages include lower temperature than that of water ice and not leaving any residue...
(solid carbon dioxide) effects are produced by heating water to or near boiling in a suitable container (for example: a 55 gallon drum with water heater coils in it), and then dropping in one or more pieces of dry ice. Because carbon dioxide cannot exist as a liquid at atmospheric pressure, the dry ice sublimates and instantly produces a gas, condensing water vapour and creating a thick white fog. A fan placed at the top of the container directs the fog where it is needed, creating a rolling fog that lies low to the ground. As the submerged dry ice cools the water, the amount and duration of fog produced will be reduced, requiring "rest" periods to reheat the water.
Dry ice can also be used in conjunction with a fog machine to create a low lying fog effect. Dry ice is placed inside an insulated container with an orifice at each end. Fog from a fog machine is pumped in one side of the container, and allowed to flow out the other end. Although this technique does allow an individual to create low lying fog "on the cheap" (when compared to the cost of renting cylinders of liquid CO2 or watertight containers with integral heaters), the volume of low lying fog produced is typically less, and is more susceptible to atmospheric disturbances.
Nitrogen
Liquid nitrogenLiquid nitrogen
Liquid nitrogen is nitrogen in a liquid state at a very low temperature. It is produced industrially by fractional distillation of liquid air. Liquid nitrogen is a colourless clear liquid with density of 0.807 g/mL at its boiling point and a dielectric constant of 1.4...
(N2) is used to create low lying fog effects in a manner similar to dry ice. A machine heats water to at or near the boiling point, creating steam and increasing the humidity in a closed container. When liquid nitrogen is pumped into the container, the moisture rapidly condenses, creating a thick white fog. A fan placed at the output of the container directs the fog where it is needed, creating a rolling fog that lies low to the ground. These types of machines are commonly referred to as "dry foggers" because the fog created by this method consists solely of water droplets, and as it dissipates there is little to no residue left on any surfaces. Dry Fogger is also a trademarked name for a particular brand of this style of fog machine.
Historical usage
The Globe TheatreGlobe Theatre
The Globe Theatre was a theatre in London associated with William Shakespeare. It was built in 1599 by Shakespeare's playing company, the Lord Chamberlain's Men, and was destroyed by fire on 29 June 1613...
(1598–1613) reportedly used smoke effects during performances for atmosphere and special effects.
Awards
The techniques and technology for creating smoke and fog effects are continually evolving. The individuals who create and develop theatrical fog for use in the entertainment industry have received numerous recognition for their efforts.Technical achievement awards
- On March 7, 1992 the Academy of Motion Picture Arts and Sciences presented a Technical Achievement Award to Jim Doyle for the design and development of the Dry Fogger, which uses liquid nitrogen to produce a safe, dense, low-hanging dry fog.
- On February 28, 1998, the Academy of Motion Picture Arts and Sciences presented a Technical Achievement Award to James F. Foley (UCISCO); Charles Converse (UCISCO); F. Edward Gardner (UCISCO); Bob Stoker and Matt Sweeney for the development and realization of the Liquid Synthetic Air system.
- On January 4, 2008, the Academy of Motion Picture Arts and Sciences presented a Technical Achievement Award to Jörg Pöhler and Rüdiger Kleinke of OTTEC Technology GmbH for the design and development of the battery-operated series of fog machines known as "Tiny Foggers."
The operating characteristics of this compact, well-engineered and remote-controllable package make possible a range of safe special effects that would be totally impractical with larger, more conventional fog units.
Scientific and engineering award
- On the 25th of March, 1985, the Academy of Motion Picture Arts and Sciences presented a Scientific and Engineering Award to Günther Schaidt of Rosco Laboratories, Inc. for the development of an improved, non-toxic fluid for creating fog and smoke for motion picture production.
Carbon dioxide
Carbon dioxideCarbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
is heavier than, and displaces, air and as such can present a serious hazard
Hazard
A hazard is a situation that poses a level of threat to life, health, property, or environment. Most hazards are dormant or potential, with only a theoretical risk of harm; however, once a hazard becomes "active", it can create an emergency situation. A hazard does not exist when it is not...
. Unsafe concentrations of carbon dioxide will initially cause headache
Headache
A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
s, nausea
Nausea
Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...
, blurred vision
Blurred vision
-Causes:There are many causes of blurred vision:* Use of atropine or other anticholinergics* Presbyopia -- Difficulty focusing on objects that are close. The elderly are common victims....
, dizziness
Dizziness
Dizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness....
and shortness of breath. Higher concentrations will result in loss of consciousness and death
Death
Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....
due to suffocation
Suffocation
Suffocation is the process of Asphyxia.Suffocation may also refer to:* Suffocation , an American death metal band* "Suffocation", a song on Morbid Angel's debut album, Altars of Madness...
. When using compressed carbon dioxide or dry ice
Dry ice
Dry ice, sometimes referred to as "Cardice" or as "card ice" , is the solid form of carbon dioxide. It is used primarily as a cooling agent. Its advantages include lower temperature than that of water ice and not leaving any residue...
, care should be taken to ensure there is sufficient ventilation
Ventilation (architecture)
Ventilating is the process of "changing" or replacing air in any space to provide high indoor air quality...
available at all times, and that procedures are in place to rapidly evacuate CO2 from any enclosed space in an emergency.
Liquid carbon dioxide (−56.6 °C) and dry ice (−78.5 °C) present a significant risk of frostbite
Frostbite
Frostbite is the medical condition where localized damage is caused to skin and other tissues due to extreme cold. Frostbite is most likely to happen in body parts farthest from the heart and those with large exposed areas...
if mishandled. Proper protective clothing, such as long sleeves and glove
Glove
A glove is a garment covering the hand. Gloves have separate sheaths or openings for each finger and the thumb; if there is an opening but no covering sheath for each finger they are called "fingerless gloves". Fingerless gloves with one large opening rather than individual openings for each...
s, should always be worn when handling these products. Liquid carbon dioxide, stored in compressed cylinders, also presents all the hazards attendant to materials under pressure and should be handled accordingly.
Liquid nitrogen
Nitrogen itself is relatively non-toxic, but in high concentrations it can displace oxygen, creating a suffocation hazard. Liquid nitrogen (−195.8 °C) presents a significant risk of frostbite or cold burn if mishandled. Proper protective clothing, such as long sleeves and gloves, should always be worn when handling these products. Liquid nitrogen is stored in compressed cylinders, and therefore presents all the hazards attendant to materials under pressure and should be handled accordingly.Theatrical fog and artificial mists
A number of studies have been published on the potential health effects presented by exposure to theatrical fogs and artificial mists.The first study that was completed was done by Consultech Engineering, Co. under contract to Actor's Equity. The findings of the Consultech study were confirmed by two additional studies—a Health Hazard Evaluation
Health Hazard Evaluation Program
The Health Hazard Evaluation program is a workplace safety program administered by the National Institute for Occupational Safety and Health . It was developed by NIOSH to comply with a mandate included in the Occupational Safety and Health Act of 1970 to investigate occupational hazards reported...
completed in 1994 by the National Institute for Occupational Safety and Health
National Institute for Occupational Safety and Health
The National Institute for Occupational Safety and Health is the United States’ federal agency responsible for conducting research and making recommendations for the prevention of work-related injury and illness. NIOSH is part of the Centers for Disease Control and Prevention within the U.S...
, and another one in 2000 by the Department of Community and Preventative Medicine at the Mount Sinai School of Medicine
Mount Sinai School of Medicine
Mount Sinai School of Medicine is an American medical school in the borough of Manhattan in New York City, currently ranked among the top 20 medical schools in the United States. It was chartered by Mount Sinai Hospital in 1963....
and ENVIRON; both prepared for Actors Equity and the League of American Theatres and Producers, focused on the effects on actors and performers in Broadway
Broadway theatre
Broadway theatre, commonly called simply Broadway, refers to theatrical performances presented in one of the 40 professional theatres with 500 or more seats located in the Theatre District centered along Broadway, and in Lincoln Center, in Manhattan in New York City...
musicals. The conclusion of all three 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 stimulated 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 theatres, 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
Entertainment Services and Technology Association
The Entertainment Services and Technology Association is a live entertainment industry organization. From their website:"ESTA is a non-profit trade association representing the entertainment technology industry dedicated to a core mission of Building the Business of Show Business...
(ESTA) 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 ESTA 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.