CO2 Special Effects Safety

If you’ve been to a live concert or stage play, one of the coolest effects is “smoke.” A shallow pool of white smoke covering the stage creates a surreal visual experience. The "smoke" can also be released from above the stage where it makes lighting effects like lasers more visible to the audience. 

What you may not know is that most of these "smoke" effects are created by quickly releasing liquid carbon dioxide (CO2) into the air. As the CO2 liquid expands to a vapor, it condenses the moisture in the air and creates the "smoke" effect.

The benefits of CO2-based smoke or fog include:

  • quick releasing for instantaneous effect
  • odorless and tasteless properties
  • quick dissipation into air

However, concert “smoke” effects created using liquid carbon dioxide (CO2) can pose severe hazards to the public and venue staff if used in improperly ventilated areas.

As we've detailed in past articles restaurants and bars use liquid CO2 to put bubbles in soda and beer. These businesses store the liquid CO2 in bulk storage vessels or in high pressure cylinders. Event venues store the same gas in the same way. However, unlike using CO2 to carbonate drinks, in concert venues it is released into the air. As CO2 is heavier than other gases and normal air it will collect on the floor first and over time fill an enclosed space.

CO2 used to create spooky Halloween effects

Just like CO2 used in live concerts and stage plays, CO2 is also used to create many spooky effects like fog, haze, mist or smoke during Halloween season. While many homeowners can purchase readily available fog machines for trick-o-treaters, a more cost-effective and simple means is to create your own spooky effects with - dry ice!

In creating these spooky effects like those you would see in the movies, the process is quite simple and involves adding dry ice to hot water in an insulated container (adding optional food coloring) and repeating to maintain a truly ghostly scene.

You can read our step-by-step guide on "How to create your own fun CO2 experiment at home" which includes instructions for creating these spooky special effects as mentioned above.

It is incredibly important to remember that while CO2 experiments can provide exceptional fun, excitement, and thrills - ensuring proper CO2 safety guidelines is vital.

And don't worry. The team at CO2Meter is here to help ensure that your "Spooktacular" special effects are not only fun, but safe too! 

CO2 Risks in Spooky Effects, Concerts, Venues

Because CO2 is used to create these effects and while a small rise in CO2 levels is not noticeable or harmful, at concentrations up to 1% (10,000 ppm) it will make some people feel drowsy.

Concentrations between 1% and 5% can cause dizziness, headaches, visual impairment, and unconsciousness in as little as a few minutes. And according to the National Institute of Occupational Safety and Health (NIOSH) concentrations above 5% (50,000) may cause asphyxiation, even in the presence of sufficient oxygen.

When used properly and according to the manufacturer’s specifications CO2 effects equipment used at event venues are safe. However, as in any application that uses CO2 in enclosed spaces, human errors can occur. This is also true, for those individuals using dry ice to create experiments - without proper PPE equipment and handling of CO2 in confined spaces, this could involve severe injury.

The following tips are commonly utilized to ensure safe practice when using CO2 special effect products:

  • Always install your CO2 jet or use your CO2 gun at a distance further than 5 feet away from any personnel in the direct line of fire
  • Never shoot your CO2 jet directly into an individuals face for an extended period of time as it will displace ambient air and can cause asphyxiation 
  • Train your employees or any personnel who will be operating the CO2 equipment to use proper technique and understand how to shut off the tank in case of an emergency
  • Utilize an emergency shut off instruction sheet and place near the CO2 tanks
  • CO2 blasts should be approximately 3-5 seconds in duration
  • CO2 should be used in areas with proper ventilation and air circulation
  • We always recommend the use of a CO2 safety monitor

To provide perspective, for those that do not take precaution there are examples of injury from improperly using carbon dioxide such as:

  • A theater technician at the Smokey Mountain Opry Theater in Pigeon Forge, TN experienced an unfortunate fatality while two other technicians were sent to the hospital due to a CO2 gas leak during a performance. Authorities later discovered that a safety valve was left open on the effects equipment.
  • When working with dry ice and special effects a study at the University of Iowa showed that heightened CO2 levels changed the acidity in the brain which plays an essential role in the fear response. Several of the experiments described in the Iowa paper showed that inhaling air with high levels of CO2 triggered strong fear reactions in mice. CO2 levels in any enclosed space will rise naturally over time due to normal human respiration.

What does this mean? For starters, you should always create your experiments or special effects involving dry ice in a properly ventilated space. This is critical because the excess carbon dioxide from the dry ice can pose significant health risks if contained in confined spaces. Do not store dry ice in a home or office freezer as the freezer is not cold enough to maintain the integrity of the dry ice.

Additionally, ensure that you can mitigate any emergencies from occurring by wearing proper PPE equipment (this means - gloves especially when handling dry ice, goggles, and clothing) as well as ensuring portable or fixed CO2 safety monitors are present to protect yourself and those around you.

Remote CO2 Storage Safety 3 Alarm

To protect against high levels of CO2 in concert venues and theaters, our Remote CO2 Storage Safety 3 Alarm is the best solution. It is designed to protect customers and workers near stored or released carbon dioxide. Because it meets all NFPA, IFC, and NBIC requirements as well as the OSHA and NIOSH time-weighted average (TWA) standard for employees, the alarm will not only protect audience members, but will protect staff in case a CO2 leak occurs.

Additionally, for those working with dry ice and CO2 experiments at home or in the office, our Personal 5% CO2 Safety Monitor and Data Logger can be used to protect individuals and can be clipped right on your belt buckle for "On-the-Go" safety. This personal monitor features real-time CO2 measurements, as well as audible/visual indication should CO2 levels exceed the standard safety thresholds. 

As it turns out, regardless if you are using carbon dioxide (CO2) to create magnificent effects during concerts, or providing a bubbling Halloween display for your neighborhood - always remember to have fun, but be safe.

Do you have additional questions or concerns on CO2 safety monitoring or special effects? Email us at

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