I have a bong with ice catchers in the neck and I’ll put (water) ice into it to cool the smoke. But if I wanted industrial strength cold, could I use dry ice? Or does this present a suffocation risk?
Wow. This goes to the top of the list of “things that I never knew I needed to know”.
I never touch the stuff. I don’t even drink alcohol. But now you piqued my curiosity.
My WAG - we are very sensitive to elevated blood CO2 (much more than low O2); odds are you’ll just exhale faster.
Not a good idea in fact it’s a bad bad bad idea
Burns
Asphyxiation
In addition to inhaling superchilled air that is somewhere around −100 °F:
Symptoms of carbon dioxide poisoning include
- nausea,
- vomiting,
- dizziness,
- headache,
- rapid breathing,
- fast heart rate, and
- flushing (warmth, redness, or tingling of the skin).
Symptoms of severe cases of carbon dioxide poisoning may include
- confusion,
- convulsions, and
- loss of consciousness.
Sounds like a great time!
Stranger
Yeah, no.
I would not do that thing.
It may explode your bong. Bad juju.
I don’t partake myself, but aren’t bongs typically made of glass?
Aside from how bad an idea breathing that high a concentration of CO2 seems like, wouldn’t the drastic temperature variances between dry ice and combustion do major harm to the glass?
Not certain it will kill you, but your survival odds don’t look so great.
If you try it, give your heirs your Dope login info first, so they can report back here.
Would it be?
Pulling smoke and water vapor across a chunk of dry ice then some distance …. I don’t suspect it would get so cold.
More likely cracking the bong is the likely outcome.
One deep inhalation of even pure CO2 is not likely to cause major CO2 elevation let alone toxicosis.
Clearly we cannot solve this question via pure analysis. We need data, Jim!
OP needs to run some experiments and report back. If he survives!
SCIENCE!!
Pro-tip: don’t drink a fifth snd smoke two bowls before starting the experiment. You might think you’re gathering data for the control arm of your experiment, but you’re really setting up an out-of-control 2nd arm of your experiment. 
Yeah, dry ice sounds like a very bad idea. Maybe add H2O ice and salt to the bong water. That should get things plenty cold!
A case of significant CO2 exposure -
We could expect the heat transfer to be significantly worse than bubbling through ice water, so the result is doubly unknown.
Unlike water ice that has to first melt and then evaporate, ‘dry ice’ (frozen CO2) will sublimate directly as soon as the surface temperature exceeds −109.2 °F (−78.5 °C), so the emitted gaseous carbon dioxide will join directly with the smoke particles and heated air instead of just cooling it. Carbon dioxide also has a higher molecular weight and a lower gamma than water vapor. Depending on how fast the hot air is passed over the dry ice it may contribute a substantial amount of gas volume which probably won’t come to a thermodynamic equilibrium before it is inhaled.
Stranger
I’m sure it would be possible to design a bong that cools the smoke with dry ice but doesn’t let the carbon dioxide mix with the smoke stream. But just dropping a piece of dry ice into the water in a standard bong won’t do that. Although it would look awesome.
When I was in high school, I was helping out at a friend’s winery. I was fishing out a lid that had fallen into a fermentation tank and, without thinking, inhaled while leaning far into the tank. I felt like I’d been kicked in the head. Fortunately, I lurched back and didn’t fall in.
Better yet, a bong with an integrated solid state chiller, reverse osmosis filter to pull out excessive resins, and an exhaust gas recirculator and closed loop feedback so that you can set it to the specific temperature and THC concentration for the perfect hit every time. Never mind the dry ice, let’s mock up a prototype, incorporate an LLC, and send a pitch out to every SiVal venture capitalist who is open for business on a Saturday night.
Stranger
Thread winner.
Unlike inhalation of other inert gases such as nitrogen or helium, inhalation of high levels of carbon dioxide by humans and probably most other mammals is unpleasant and/or painful.
It will burn your lungs and not allow you to inhale. I made the mistake of smelling my fermenting grapes without ventilating first. The very second t hits your lungs they stop inhaling. Try nitrogen.