How to Make Dry Ice - With a Fire Extinguisher!

About: Random Weekend Projects

Here's how to make dry-ice at home, or wherever you feel like it!  All you need is a pillow case, and a CO2 fire extinguisher.

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This project was inspired by: Theo Gray (Mad Science)

Step 1: Watch the Video!

WARNING: Dry Ice is extremely cold! (-78C/-109F) and can cause instant frost-bite to exposed skin.  This project should not be attempted without adult supervision and adequate training. Misuse, or careless use, of tools or projects may result in serious injury.  Use of this video content is at your own risk.

Step 2: Getting the Equipment

To make dry-ice, you need to secure a ready source of compressed liquid CO2.  How about a CO2 fire extinguisher?

Some fire extinguishers utilize CO2 as the medium for suppressing fires because it's very clean and doesn't leave behind any residue.  When pressurized liquid CO2 is quickly depressurized, the CO2 expands to a gas, and cools its surroundings.  This is called adiabatic cooling.  Because the CO2 sublimates directly into a gas, there's no mess to clean up after discharge!

Where to find one?

I called around to some fire-equipment companies asking about CO2 fire extinguishers.  I hadn't seen these types of extinguishers much and was looking for where I could buy one used, or rent one just for experimenting.

By chance, one man I talked to said he had a 15lb CO2 extinguisher in storage, and he would give it to me for free!  If you don't get as lucky, try calling a company that re-charges CO2 extinguishers and ask them if you can rent one, or borrow one for a science project.

Most fire extinguishers you see are filled with dry chemical.  These are NOT what you want.  It has to be Carbon Dioxide.

You can distinguish a CO2 fire extinguisher in a few different ways;

1. Look for stickers or markings on the side of the tank that indicate "Carbon Dioxide" or "CO2".

2. Look for a servicing sticker or tag with a hole punched next to "CO2".

3. Look for a unusually large discharge horn.  This is an oversized large black nozzle at the end of the hose.

4. No pressure gauges is also a good indication.

These types of extinguishers aren't typically in public view.  They are mainly found in restaurant kitchens, mechanical rooms, and in areas that hold sensitive equipment like computers.  Interestingly enough, the CO2 is "food grade CO2".

Carbon Dioxide fire extinguishers are usually referred to in terms of pounds.  For example, a 15lb CO2 extinguisher is charged with a 15 lb weight of liquid CO2, and this can be identified by markings on the handle showing the full and empty weights.  

Step 3: Making Dry-Ice

Operation of the fire extinguisher is the same as any other.  Just remove the locking pin, and press down on the handle.

What you'll see is a forceful jet of Carbon Dioxide vapor blasting from the discharge horn.  The gas is extremely cold, and may take your breath away if you get too close.

The trick to getting dry-ice!

Here's the trick .. trap the cold!  

Using a porous cloth material, like a pillowcase, cover the end of the discharge horn and pull up all the loose material.  

When you have a good grip, give it a 4-6 second blast!  Hang on tight because there will be a lot of pressure pumping into your pillowcase and you need to keep it from blowing away.

Oh yeah, it's also going to be pretty loud, so warn your family before you do it.  That's speaking from experience!

When you remove the pillowcase, there will be a solid buildup at the bottom of the bag, as well as on the nozzle.  Make sure to save that into the bag, then open it up to see what you got!

I found chunks of dry-ice snow, and digging down near the bottom I found enough to make a good sized dry-ice snowball!

Dry-ice is -78C, so using insulated gloves is recommended.  I didn't use gloves, and while I did feel a little cold nip every now and again, I found for the most part that if I kept the ice moving around quickly, it didn't have a chance to sit long enough to give me a frost-bite.

The dry-ice sublimates directly from a solid to a gas, so in an attempt to make it last longer, I transferred it to a small bowl to keep it together, and reduce the exposed surface area.

Step 4: Things to Do With Dry Ice!

The classic dry-ice experiment is to place a few chunks in a container, and pour some warm water overtop.

This creates a flowing fog effect, that is common at halloween parties in something like a witches brew.  The fog can even be poured out to form a cascading waterfall of mist that will flow gracefully over your countertop.  The best part is, there's no mess to clean up!

I put a few chunks in a condiment container and screwed on a lid with a vent hole in the cap.  When I shook it up, the reaction accelerated and I got a little CO2 geyser rocketing out of the top!  The pressure was enough to make me wonder if it could be used to drive a small motor of some sort?

I tried making a poor man's version of liquid nitrogen, which actually flash-froze an orange!

The remainder of the dry-ice went into making a nice batch of carbonated ice-cream.  Delicious!

Step 5: Other Projects

Well, there's how to make "on demand" dry-ice, in a portable and "do-it-yourself" fashion.

Saying that, I should mention that it cost just under $30 to refill the tank to get about 5 lbs of dry-ice.  Contrasting that with the cost of dry-ice at the local grocery store ($1.00/lb) doesn't make financial sense, but this method is much more fun!

If you haven't see the video yet, it's not too late.  Watch it here!

If you like this project perhaps you'll like some of my others. Check them out at



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    67 Discussions


    6 years ago

    I think it will work for fireworks


    6 years ago on Step 5

    I think dry ice might be used to eliminate ant nests. I think by placing a chunk of dry ice on the ant mound then covering with something like a garbage bag then weighting the sides of the bag well the carbon dioxide would work its way into the nest, displacing the oxyygen as it sank to the bottom most part of the nest. Because it doesn't poison, so much as axphysiates the ants, it would be completely safe. The soldier ants,, by attacking the chunk would die simply by coming into contact with the cold chunk of co2. I haven't had the opportunity to try this but I think it would work.

    3 replies
    The King of Randompaqrat

    Reply 6 years ago on Step 5

    Wow, what a great suggestion! I think you're right!! Thanks for sharing such a great project idea! :)

    paqratThe King of Random

    Reply 6 years ago on Step 5

    I think it might also work to rid one's carpet of a flea infestation. I'm a bit hesitant to use the sprays. Seems like if it dissapated enough oxygen it might kill the eggs too. Wouldn't want to lay it on too thick though if you had small pets or rugrats.


    Reply 6 years ago on Step 5

    Try Diatomaceous Earth (food grade) instead. It works as a non-toxic pesticide and is so safe that many people take it as a supplement in water. It is great for killing internal parasites without making you sick to get rid of them. External Usage: it has microscopic edges that scratch up the bodies of the insects. When this happens they dry out internally and die. Just poof the dust around the areas where you have crawlies and take off for half an hour while it settles. Then leave it for a few days. In out of the way areas like besides and behind the refrigerator leave it indefinitely. Dead bug. No poison to make any person or pet in your home sick. . It’s perfectly safe but don’t breathe it. Sneeze city (it is a powder after all). It is already in use in the food industry in bulk storage facilities.

    Just so you know, D.E. is a fossilized form of a single cell algae, so completely natural. Try sprinkling it on an ant hill and leaving it. You can also rub it into your pets fur. Put it in a sock and rub away. Then comb them and reapply every so often.


    6 years ago on Introduction

    neat instructable!
    being a brewer by trade, I have ready access to Compressed CO2, fabricating some sort of expansion device could make this interesting, if anything, just for giggles and stupid brewer tricks ! :D

    But, a CO2 canister equiped with a fire nozzle should be readily refillable at any commercial, or industrial gas/ welding supply shop. could be something interesting for if one wants or needs dry ice there and now and on demand.

    as others have stated in the comments, dry ice is usually available through various grocery stores for $1 a pound.. I get mine at all the krogers around town. I usually get some when I'm playing around with cloudchambers to observe radioactive and cosmic particles.

    because why not? :D

    BUT!.. every year at Halloween, the brewery I work for turns the place into a haunted house for the night, and this might be a way to negate the Dry Ice bill for the event.

    2 replies

    I discharged a full 15lb tank and got 5 lbs dry ice. It seems to be a 3:1 ratio liquid CO2 to Dry Ice. I'm sure there are more efficient ways to get more, but that's what I got with the pillowcase method.

    Thanks for your comment! Do you get your compressed CO2 at a good price? I plan to completely discharge my extinguisher in one go to see how much ice I get, but I doubt it will be anywhere near 28 lbs worth. It costs me $28 to fill up the tank, so it may not negate your dry ice bill after all?

    I'm intrigued by your cloud chamber talk. Do you have videos?


    6 years ago on Introduction

    Nice. But wouldn't it be more accurate to say you're collecting C02, rather than making it?