Video: HOWTO make a dry ice bomb (this is not safe).

(Disclaimer: BoingBoing does not recommend that anyone but professional cryo/pryotechnics experts try this. "Dry ice bombs" can cause property damage, serious injury, or death. See reader comments after the jump for more detail on dangers). Dry ice, a plastic water bottle, and a good throwing arm are all you need. Link to a homemade instructional video from some dudes in Wyoming Ohio, circa 2003.

Reader comment: Jeff Roberts says,

You need to be very, very careful with dry ice. I spent one week in the hospital with a collasped lung and 4000 stitches, and my then-future wife received 500 of her own. And I wasn't even making a bomb, just playing around with dry ice – capped the lid and didn't unscrew it quickly enough. After a few seconds, the mountain dew glass bottle it was in exploded. It blew out all of the windows on the first floor of our house, and neither of us could hear anything for days. Be very, very careful.

Tom says,

A Georgia Tech student made some last fall and when they were discovered by the Atlanta Police, the police went on national television and called it an act of terrorism! Apparently a janitor found one that hadn't exploded, and it went off in his hands, which resulted in his ears ringing (the press referred to this as an "injury"). Hollot was actually charged with a felony but plead out to two misdemeanor counts with 24 months probation and 100 hours of community service.

Personally, I find it mind boggling that a media circus and a felony prosecution started over something far less dangerous then your typical 4th of July firework, but before your readers go out and build one of these things they might want to take heed that in the "post 9/11 world" the authorities have gone completely nuts. Link to news story.

More links: one, two.

Reader comment: oboreruhito says,

This poynter.org link points out MSNBC's Red Tape Chronicles' tut-tutting on "gruesome stunts and risky pranks that mar video sites": Link.

Dave Hardin says,

Just thought you might want to add a cautionary note. CO2 "bombs" have an unforseen side effect. The cold of the dry ice makes the PET plastic of the soda bottles very hard and brittle. So, when the pressure gets so great that the bottle explodes, it sends lots of small jagged plastic "shrapnel" in all directions. Can really do some damage to folks who might be unwise enough to follow this howto. Especially if they try to throw it before it explodes and they misjudge how long it will take.

Mark Zinthefer says,

I have a friend who works as a counselor at a state high school. Once
day some kids got their hands on some dry ice and put it in a bottle
as referred to in this BB post. The kids ran, the bottle tipped over
and the cap shot out. The cap went through my friends window
shattering it and embedding glass in his bathroom door. He was lucky
since he was standing in front of the window shortly before it went
off and happened to step into the bathroom before it exploded. Had he
gotten hit he would most likely have gotten injured by the cap not to
mention lacerated by the glass.

So while I agree with the reader Tom that this isn't terrorism, I
think it's pretty flippant to say that these are "far less dangerous
than your typical 4th of July firework". Perhaps fireworks just suck
where Tom's from.

CO2 bombs can be dangerous and if some kid gets busted by The Man, I
can hardly sympathise if the kid doesn't take proper precautions and
take the safety of others into account.

Darren Finnecy says,

Your post on Dry Ice bombs brought back some memories of the good 'ol days when I was growing up in Saratoga, CA. Dry Ice was difficult to get, we had to drive way out to an industrial ice house in East San Jose where the gruff guys in plaid flannels were more used to selling truckloads of the stuff than the bits wrapped in newspaper we were after.

The video of our boys in Ohio truly doesn't capture the immense explosive percussion you can generate with one of these in a 2 litre soda bottle. It is really awe inspiring. The darn things can sit there for 5 or 10 delicious tension building minutes, bulging and creaking and bubbling away. When the tension made us feel like the bomb was in our bellies it would give one final creak and explode with a puff of white smoke and a massvie percussion, shaking windows around the suburbs in all directions. I never heard a traditional firework that could come close to the sound these would generate.

Occasionally one might never go because enough ice hadn't been added. These cases required a dry ice bomb squad to deactivate, the guy down the street with a bb gun would fit the bill.

The most amazing thing that ever happened to me was when a buddy and I were behind a grocery store and we had dropped a bomb in a garbage can. We waited for it to go off and started to drive off in fits giddy adrenaline when a police car blocked our exit. We sat there, waited for the officer to come to the car.

"You boys want to tell me anything about that explosion I just heard?"
No use lying now. And we were a bit intrigued as the legality of dry ice bombs had been the subject of long and intricate debate in my circle of friends.
"Yes sir, It was a dry ice bomb, you see, "(insert explanation of making the bomb here)
Cop gives us a slow look, "Could I see the ice and the bottles you are using please?"
We get out and show him our 2 litre bottles and the crushed ice in a cooler in the back.

He let us go. Didn't even take the ice. Told us to find a better place to play with these and not to use glass. (Duh)

Times have changed, I doubt it would be as casual these days. Too bad really, I always looked forward to showing my kids these things.

Zane Bruce says,

I've been making these on and
off for more than fifteen years, and there are some safety notes to
be aware of:

Depending on how much dry ice is used (a good 1.5 or two handfuls of
pellets to a 2/3 to 3/4 full of water 2litre bottle is what I use)
, you can have a bomb that blows in a few seconds after you seal and
throw it, or if you use less dry ice, and less or no water, a bomb
that may wait ten minutes, several hours, or even not blow until
disturbed (cf, the one the janitor found).

They are definitely not 'less dangerous than a 4th of july firework',
as I have seen these bombs shatter windows, and throw gravel and
fragments of plastic with enough force to injure if you are within a
couple of metres. In particular, the hard plastic around the cap can
sometimes break into sharp fragments. At close range, (ie holding it
or at a metre or so), the blast is probably strong enough to burst
eardrums and damage eyes.

They're not as bad as some explosives, but they are explosives, and
need to be treated like any other explosive device – with caution.

Zane
(Already down much of my hearing due to excessive explosive use, and
short half an eye (although not from explosives.).

Kevin Marks says,

Andrew (10) and Christopher(9) demonstrate the technique using a film can and small amounts of dry ice in their 'Fun with Dry Ice' video. Link

Kevin says,

i was involved in making dry ice bombs in october '01. i was in 9th grade and was sent to juvinal hall on two felony charges, making an explosive device and setting off an explosicve device. Link. the following is copied from the union tribune:

Four students at the School of Creative and Performing Arts on Alta View Drive in San Diego were taken to Juvenile Hall and a fifth student was hospitalized with injuries to his thumbs after an improvised explosive device detonated inside a school bathroom yesterday, police said.

The Metro Arson Strike Team was called to the school after the explosion about 11 a.m.

A 14-year-old brought dry ice (solidified carbon dioxide) to school after learning about it in chemistry class, said San Diego police Lt. Dave Elliott. The boy's friends reportedly bought sodas from a vending machine and used the bottles and dry ice to make six crude bombs.

When one bottle failed to explode, the 14-year-old picked it up and shook it. That resulted in a blast and serious injuries to the boy's thumbs and fingers, police said. The other five devices were found on school grounds.

Police said the 14-year-old will not be charged but that the four others were arrested on suspicion of making the devices.

The magnet school's 1,500 students were taken out of all classrooms as a precaution for about an hour.

thats basicly right. excpt he didnt pick it up and shake it. he just picked it up after it had been made. and it went off in much less then ten seconds. also the school was evacuated for the rest of the day, not just an hour. we all sat on the field for half the day and every students backpack was searched for "bomb making materials", in this case, a plastic bottle. so be careful, and smarter then we were. thanks.
p.s. all charges were dropped and none of us were in juvinal hall for more then 4 or 5 days.

anonymous says,

I have it on good authority that with one of these bombs, used
correctly, you can launch a pineapple for 11 seconds. Look up in the
air and count to 11, and you'll realize how much energy a 2-liter bottle
can hold (around 300 kilojoules).

They're much safer, quieter, quicker, and more fun if you tie them to
a lead brick and dump them in a garbage can full of water. The water
goes two stories high and the can is only 2/3 full afterward.

Mike says,

On those slow Friday afternoon's in the lab, in between asking the new lab technician to go to the university storeroom and get some fallopian tube (it was a reproductive biology lab BTW), and doing some real work we used to make small dry ice bombs.

We would pack one and a half dry ice pellets into small 1.5ml polypropylene plastic tubes (eppendorf tubes). These would go off with a delightful bang which was loud enough to scare seven colours of shit out of any new lab. tech. into whose pristine white lab coat pocket you had dropped the device a good 5 minutes earlier.

However, the distance that the plastic tube shards could be scattered, even though you would have thought they were contained in the lab coat pocket, was quite amazing and always put me off trying a larger container.

Geeky comment: It is interesting the way that the Dry Ice turns to liquid before exploding in these devices when normally it just sublimates (goes straight to gas). I think it must have something to do with the pressure increase in the bottle capturing it as a liquid.