In this blog post we look at how dry ice is formed, how it is used, and how it can be dangerous if used in confined spaces.
Dry ice is useful for many things, including cleaning, refrigeration and even fog effects in theatres.
However if it is if stored or used improperly it can be dangerous.
What is dry ice?
Dry is is essentially a block of frozen carbon dioxide.
A block of dry ice has a surface temperature of -78.5 degrees Celsius (-109.3 degrees Fahrenheit) and is most commonly used to preserve items that must remain cold or frozen, such as ice cream or biological samples.
It is also used as a form of cleaning, known as dry ice-blasting, where dry ice is accelerated in a pressurised air stream and directed at a surface in order to clean it.
In normal atmospheric conditions, dry ice undergoes a process of sublimation, which means as it breaks down, it turns directly from a solid to a gas.
This is useful for sending something frozen from one location to another, as at the end of the journey there will be no messy liquid left over like normal ice.
Sublimation can also be accelerated by placing dry ice in water to create dense clouds of smoke-like fog. This is used in fog machines at theatres, haunted house attractions and nightclubs (for example, as we discovered at Northern Restaurant and Bar 2017, a small piece of dry ice might be used in a drink for theatrical effect)
Due to its extremely cold temperature, any person handling dry ice should wear heavy gloves, as it can easily damage skin that comes into direct contact with it and cause a dry ice burn.
Another important hazard to consider is the potential exposure to an increased level of CO2. If you are around dry ice it is important to make sure it is stored in a well-ventilated area, as CO2 is heavier than air and during sublimation it can concentrate in low areas or enclosed spaces like a car or room.
Dry ice, carbon dioxide and the displacement of oxygen
The woman was providing catering services and she had stored boxes and coolers of ice cream packed with dry ice in the back of her SUV.
During her journey, the dry ice had started to turn to CO2 gas and she had failed to roll down her windows, meaning her car was not well ventilated.
The CO2 displaced the oxygen in her car, causing her to pass out, and she was found in the middle of an intersection with her foot still on the gas pedal and the SUV in drive.
Unconsciousness is just one of the physiological effects of CO2, as it can also cause drowsiness, reduced hearing, increased heart rate and blood pressure, headaches, tremors and dizziness, to name a few.
Luckily the woman recovered from CO2 poisoning, however an increased concentration of the gas could have resulted in her death.
As CO2 is colourless and odourless, this makes it hard to detect. To raise the alarm when there is exposure to higher than normal levels of CO2, Analox offer a wide range of carbon dioxide monitors – from portable monitors like the Aspida to fixed monitors like the Ax60.
These cater for several industries including beverage and hospitality, fast food, laboratory, offshore and marine, commercial kitchens and agriculture.
To find out more visit our products page for CO2 detection.
Update: It is still sad to see incidents concerning dry ice in the news. In May 2016, Fox news reported the story of a courier who passed out on the side of the road when a package containing dry ice leaked inside his car. Fortunately, he was found in time and survived.
Author: Araminta Hartley, Content Writer
Founded in 1981, Analox Sensor Technology provides niche and custom gas detection solutions to industries including beverage and fast food, commercial diving and laboratories. Analox has over 325 years of collective, specialist electronics and software engineering expertise, as well as a worldwide distributor network. Contact us to see how we can provide expert gas monitoring solutions and help you achieve your goals.