If you’ve grown up watching television, you might already be aware of the enigma that is dry ice. You’d often see your favorite dance performers surrounded by a thick cloud. For a child, it quickly became the source of all mysteries. Of course, most of us would think it’s no different from the clouds we see in the sky. And many adults would nod along because they were equally as confused.
Whether it was the entrance of a supervillain in a sci-fi film or an experiment conducted by a YouTuber, dry ice always stole the show. And even though all intrigue surrounding dry ice has been resolved, it still stands as a topic of great fascination. So if you’ve been curious about dry ice, we suggest you keep reading. Not only do we unravel what dry ice is, but also how you can make it at home.
Before we dive into the intricacies, here’s a fun fact that you probably didn’t know:
Dry ice is an environment-friendly and non-abrasive cleaning agent. It can be blasted into the smallest corners and remove the sludge that has been stuck for years. So if it intrigued you as a kid, it would excite you as an adult as well.
What is dry ice?
Dry ice might seem like a substance from outer space, but it’s only solidified carbon dioxide. The reason it’s much colder than regular ice is that it has a significantly lower freezing point. Where regular ice is formed at 0°C, dry ice has a freezing temperature of -79°C.
Due to a lower freezing point, the structure of dry ice also differs from regular ice. Its molecules are tightly packed together, leaving no room in between. The structural integrity of the molecules resembles the crystals in snowflakes. In comparison, regular ice has a crystalline hexagonal structure.
Since carbon dioxide is a gas at room temperature and pressure, solid dry ice will quickly sublimate if exposed to such conditions. You might have seen a thick cloud appearing as soon as a chunk of solid dry ice is removed from extreme cold. This happens because it skips the liquid phase altogether.
What is it made of?
Dry ice is purely made of liquified carbon dioxide. There’s no other substance or chemical that goes into its production. So instead of a long list of ingredients that make up dry ice, the only requirements are carbon dioxide and favorable pressure and temperature.
Once you get your hands on carbon dioxide, the first thing you need to do is liquefy it. Once that’s done, you move forward to freezing the compound into a solid form. You can either create large blocks or pellets, depending on the equipment you’re using.
Regardless of the shape, the dry ice will work the same. So the next time you want to cause a sensation at a birthday party or a family gathering, all you need to do is introduce a block of dry ice in the middle of the room.
Is dry ice dangerous?
It’s difficult to see solid carbon dioxide as a dangerous substance. After all, it’s the same as regular ice. However, that couldn’t be further from the truth. The name leads you to believe it’s just another version of frozen water, but its chemical properties vary greatly.
When you take an ice cube and hold it in your hand, your body temperature is enough to melt the ice. But if you even touch a pellet of solid carbon dioxide without any protective gear, your skin will begin to turn red. In case of extended exposure, you’re at a high risk of getting frostbite. At least now, we can all agree that solid carbon dioxide is in no way similar to regular ice.
Here are a few other ways exposure could harm you:
Cold to the touch
As we’ve discussed previously, a brief contact with solid CO2 could result in swelling and redness. However, the effect isn’t only visible. You can feel a burning sensation even after you’ve removed contact.
If you hold solid CO2 for longer, it will give you severe frostbite. Of course, you can treat it like any other burn. But if the matter has escalated beyond control, you’ll immediately need to seek medical assistance. So if you see your skin turning white or losing sensation, don’t waste another minute and rush to the hospital.
No room to breathe
You may remember from middle school chemistry that gasses take up the entire space of the container they’re held in. So building on that logic, a chunk of solid CO2 might seem easily manageable. But the story is entirely different once it begins sublimating.
The solid gaseous CO2 quickly takes up the entire container. So if you’re in a small place that isn’t well-ventilated, you’re risking your life. In addition, carbon dioxide is quick to replace the oxygen in the room. So breathing in a greater concentration of CO2 could cause asphyxia. In severe cases of the medical condition, you could lose consciousness, risk brain injury, or even pass away from oxygen deprivation.
Small things make a big difference.
Transporting solid CO2 is a risky business. Keeping it in a sealed container might seem like the safest option. However, that has its flaws also. If you force solid CO2 into a small space, any change in the temperature setting could result in violent ends.
As CO2 expands, it applies inward pressure on the container. When the pressure becomes too high to bear, the container explodes. So if you were thinking of adding an element of intrigue to your parties using solid CO2, you should call professionals to handle and deliver the product.
Making dry ice on an industrial scale would require you to specialize in chemical engineering. Factories producing it get their hands on CO2, which is first liquified and then cooled under extreme pressure to form pellets and blocks of solid ice.
But that doesn’t mean you only have to rely on packet dry ice. There are a few safe ways to make it at home. If you’ve got a spare fire extinguisher on hand, follow each step closely to make your batch.
How to make dry ice
- Get your hands on a CO2 fire extinguisher and a fabric pillowcase.
Step out into a lawn or an open area with your two raw materials. So even if things don’t go as planned, there will be no damage to property. While conducting this experiment, ensure there’s no child or pet nearby.
Additionally, do a double check on the fire extinguisher. Only a CO2 extinguisher would be suitable for this to work. Typically, the ones used at home are not fit for the task. You can get your hands on the right kind from the hardware store.
- Wear protective gear.
Since carefulness costs you nothing, make sure you’re fully stocked. Direct skin exposure to dry ice could cause severe damage. Therefore, you’re advised to wear thick leather gloves.
As for your clothing, wear a full-sleeved shirt and pants. That’d be even better if you could get your hand on a lab coat. Lastly, make sure you’re wearing close-toed shoes and lab goggles.
- Tie the pillowcase around the hose.
Wrap the fabric tightly around the hose. There should be no space for the gas to escape. If you’re concerned about the gas leaking, wrap duct tape where the hose meets the pillowcase.
Once you’re confident about the setup, remove the nozzle and the safety pin from the extinguisher and get ready for action!
- Pump the extinguisher.
Blast the extinguisher into the pillowcase and hold your stance for about three seconds before you stop pressing. You should feel the pillowcase get a little heavier, and a cloud will start forming outside it.
- Take out the pillowcase.
Once you’re done, carefully remove the pillowcase from the hose. If you had used duct tape to secure the setup, remove that first. Try not to tip over or spill the pillowcase. Finally, tightly wrap your grip around the opening of the cover. This ensures your exposed skin doesn’t come in direct contact with the dry ice.
- Move it to a safe storage option.
This is where the fun ends, and you must become a responsible adult again.
Carefully remove the dry ice from the pillowcase into a workable container. This includes a thermos or even an airtight plastic bowl. Using a stiff plastic spatula, scrape away the last remaining stuff.
Once you’ve successfully transferred all of it, move the container to cool and dry storage space. It’s preferable to store it in an open site, away from the reach of children and pets.
What happens if you eat it?
If you think coming in brief contact with dry ice is dangerous, you don’t even know what’s in store if you ingest it. Even though the likelihood of eating dry ice is significantly low, accidents always occur. Besides, you’re probably curious about what exactly happens.
As you ingest the dry ice, it freezes all the cells it comes in contact with. As a result, it can cause severe damage to all the organs from the mouth and esophagus to the stomach. But that’s not even the scariest bit. Once it settles in your stomach, it will probably start sublimating. Since there is no way out of the CO2, it builds up, and the pressure causes the stomach to rupture. The bottom line is that it is far from edible, so it should be avoided at all costs.
Can you store it in the freezer?
Carefully handling dry ice is only half the battle won. The other half requires you to find a suitable storage space. If your storage unit isn’t up to mark, you’re risking the safety of everyone that comes in contact with it.
It might seem that a typical freezer is suitable for storing dry ice, but CO2’s chemical properties suggest otherwise. It has a freezing point of -79°C, which is not even remotely close to what a standard freezer operates. The lowest a food-grade freezer can offer is -18°C, which is still too warm for solid dry ice. Furthermore, your refrigerator’s ventilation system is compromised as the ice sublimates into CO2 gas.
What material is best for storing dry ice?
Managing dry ice doesn’t come with an instruction manual, but there are certain dos and don’ts that you should know before you purchase a bag.
When storing it, using a suitable material is vital. Therefore, a styrofoam box or dry ice cooler will work best. You can even opt for a hard-plastic container if you’re only looking to store it for a few hours. It can then be used for shipping things like hams.
You should avoid certain materials at all costs, including fine china, ceramic glass, and fancy metal. Their structure isn’t suited to withstand the pressure exerted by dry ice.
Getting rid of solid carbon dioxide doesn’t require a complicated disposal system. Instead, all you need is a bit of patience. First, place the solid carbon dioxide in a well-ventilated area at room temperature. Beyond this point, you don’t need to do anything because nature takes care of all. Then, the solid carbon dioxide begins sublimating away until nothing’s left.
The shelf life of solid carbon dioxide depends on the conditions in which it’s stored. For example, it can remain intact for an entire day if the solid is kept in a cooler. But if you leave the ice out in the open at room temperature, it will all be gone by the end of five hours.
Dry ice might only share a name with regular ice, but it shares no properties with the latter. Where water freezes at 0°C, dry ice has a freezing point of -79°C. It’s so cold to the touch that if you hold it for a few minutes, you risk getting frostbite and losing nerve function.
Solid carbon dioxide differs from other solids in how it changes states. When most solids are exposed to heat, they melt into liquid. Only when more heat is provided do they change into a gaseous form. But solid carbon dioxide entirely skips the liquid state and directly changes from a solid to gas at room temperature.
It is not edible, as ingesting it can cause severe damage to your health. As you ingest it, it freezes all cells it comes in contact with. From your mouth to your stomach, the entire pathway is affected. And when it finally reaches the stomach, it begins sublimating into its gaseous form. The CO2 vapor builds up and pushes against the stomach walls, which may cause the organ to rupture.
It would even be devastating for animals like cockroaches if they were exposed to the highly-concentrated levels of CO2.
A specifically-built cooler can hold the solid for a maximum of 24 hours before it all sublimates into gaseous form.
Dry ice has multiple practical uses. It’s not just limited to creating intrigue at birthday parties or mystery at Halloween gatherings. The most common uses include blast cleaning, preserving frozen foods, and storing temperature-sensitive medicines. Other uses may include protecting ice sculptures from becoming a puddle or solidifying oil spills.
Apart from industrial-grade use, there are multiple ways to use it around the house. For example, you can scare the mosquitoes away or get rid of any bed bugs with the help of dry ice. It even helps promote your house plant’s growth.