What’s in fake “fog” and is it harmful?
Musicians use it. Theater companies use it. Some churches even use it. Fake fog rolling across a stage and into the crowd evokes a feeling of mystery. But what exactly is everyone around it, breathing?
There are many ways to produce a spooky-looking haze or fog, and thankfully most of the ones used today are safe for short-term exposure. They look similar, but you can distinguish them by the characteristics of the fog.
“Fog” typically refers to a low-lying mist, because in nature, “advection” fog is formed when warm, moist air moves over a cold surface or body of water. Fog is formed with tiny liquid droplets. “Haze” is more typical of a smoke effect, when the whole room or space is filled, in most cases so that lighting beams can be seen as lasers piercing the haze. The fog or haze can be generated with different substances.
The fog/haze effect comes from small partlcles of water, water mixed with glycol, or mineral oil floating in the air. Glycol (often in the form of propylene glycol or vegetable glycerin) is a component of vapes, which we’ve come to learn is harmful. Theater companies, musicians and their crews potentially breathe it for several hours, several times a week during shows. A study released in 2005 showed that cumulative exposure to fogs (mineral oil and glycols) over the previous 2 years was significantly associated with chronic work-related wheezing and chest tightness. Acute cough and dry throat were associated with acute exposure to glycol-based fogs, and increased acute upper airway symptoms were associated with increased fog aerosol overall. Lung function was significantly lower among those working closest to the fog source. (Effects of theatrical smokes and fogs on respiratory health in the entertainment industry) In addition to the toll on humans, there is also a residue left behind from these substances, which can damage electronics and furniture.
There is another option to make fog, which is generally safer. “Dry ice” is frozen carbon dioxide, and when it’s exposed to air, it cools water vapor in the air to form small droplets, resembling fog. It must be used in an area with plenty of fresh air ventilation, because the frozen CO2 evaporates directly into the air, diluting oxygen (which could be a suffocation risk in a small space). The dry ice must also be handled with gloves in order to avoid frostbite. Liquid nitrogen can be used in almost the same ways as dry ice to create fog.
If you are in the area of a fog machine and begin to have eye or throat irritation, respiratory problems, light-headedness or headaches, it’s best to head for fresh air immediately. If you’re in the cast or production company, ask about safer alternatives to whatever’s being used. Don’t be fooled–you won’t be missing out on anything when you can’t breathe well to enjoy the show and life in general!
Photo by Klara Kulikova on Unsplash
