Home made gas chamber for little children.

Quote: Originally posted by Sulaiman

More of a Societal question isn't it ? Where/when is censorship good/bad ? It's the grey area in the middle that is used to form a wedge.

I agree there should have been more focus on safety. Principles should have been explained in addition to directions. Directions like leaving an outside door open during the experiment, running household ventilation (prevent buildup in basement), a minimal room size. But at the same time I don't think it was that bad using just ~3L... possibly worse exposure by a dense roadway, or some idiot bringing their charcoal grill indoors (deadly!).

Looks to be around 1.2L of dry ice makes 1m^3 CO2 gas , with expansion ratio of 845.

I've promptly evacuated a class before, in the basement of a physics building, when their liquid nitrogen (oxygen?) alarm went off (they have a ~500L dewar hooked to the basement). Loud alarm in hallway with rotating yellow lights. Told the students to not go back and rescue someone if someone falls... that was my training with enclosed spaces & gas. Multiple examples given in that training where not just 1-2 people die, but their 1-3 would-be rescuers die too. Probably made for an interesting college experience for them

Another fun experience was in my teenage years, skiing. Multiple remote industrial buildings downslope other side of the mountain, which you could see from the highest lift at the crest. The air everywhere turned yellow , and everyone had great difficulty breathing. We could breathe the best at the top of the mountain, where it was a lighter yellow. The staff there had no idea what was happening either. There was NOWHERE we could go to escape it, it was everywhere, the entire mountain, with deeper concentrations in different areas. I had difficulty breathing for 1-2 weeks after that (great difficulty the first few days), as did all my friends. Looking back now I expect it was an insane amount of chlorine gas! Hard to comprehend that they could have made so much gas that it filled the valley they were in and, and smothered the adjacent ski resort for hours.

[Edited on 24-11-2018 by andy1988]

Quote: Originally posted by TheMrbunGee

What will happen when kids at home will actually try this, pass out and suffocate? Especially in smaller rooms. [Edited on 23-11-2018 by TheMrbunGee]

Quote: Originally posted by Sulaiman

More of a Societal question isn't it ? Where/when is censorship good/bad ? It's the grey area in the middle that is used to form a wedge.

Quote: Originally posted by Sulaiman

Sorry about the metaphor, too obscure. I believe that the 'experiment' was dangerous, and the hosts were so unprepared it is scary, but they did mention hypoxia, keeping a door open, and splashing boiling water. Any reasonable person with (as above) access to dry ice and boiling water and the video itself should make their own choices. The same members that complain about censorship seem to be overly concerned, relative to other chemistry related videos for example. I just do not want a censorship tidal wave. Of those that complained here, how many contacted the publishers to express your concerns ? Not important ?

Let's consider the weights and volumes in play here. It's impossible to get exact measurements from a video, so there's a lot of guesswork and rounding going on, but bear with me. I also apologize for Imperial units!

It looks like about an 8" pot filled with dry ice to about 3". That makes about 0.09 ft³ of dry ice (assuming a solid cylinder, which it's not, so this is high end).
Density of dry ice is about 100 lb/ft³, so this is 9 lbs of dry ice.
1 lb of dry ice turns into about 8.3 ft³ of gas, so this would create 74.7 ft³ of CO₂ (assuming it all instantly vaporized, which it doesn't, so again a high end estimate).
A "standard" small kitchen is 10ft x 10ft, and their ceiling appears to be 8ft. Let's cut that in half to a 4ft height since we're concerned about children, so that's 400 ft³ of volume (assuming the kitchen is a completely enclosed space, which it clearly isn't since it's open to other rooms, making this again a worst-case scenario).
Now let's look at two extremes, since we don't really know the extent and rate of mixing of these gases:
Zero Mixing: Assuming the CO₂ completely displaces the air with zero mixing, it would only fill the 10x10 kitchen up to 0.75ft with pure CO₂, well below kid level unless they're laying on the floor.
Perfect Mixing: Assuming it mixes perfectly with that 400 ft³ volume. Normal air is 0.04% CO₂, which is 0.16 ft³ of gas. Adding that to the 74.7 ft³ of vaporized dry ice, and dividing by the 400 ft³ room volume we arrive at 18.7% carbon dioxide content.
Reality: Somewhere in between these. There will be a concentration gradient, highest at the floor and decreasing with height. It certainly won't be 100% CO₂ at the floor, as zero mixing would suggest.


But is this number meaningless? Did I waste my time here? Perhaps! I certainly overestimated the amount of dry ice, and vastly underestimated the room size. You'd also need to consider the amount of time it takes to vaporize that quantity of ice, and the time for onset of symptoms to occur (the concentration wouldn't instantly become lethal as my analysis might suggest, and people wouldn't instantly pass out). Luckily, your body also warns you about CO₂ exposure so you'd have some indication that you should leave the area at least. So it's likely the danger is much less severe than it appears from the math.

Is there danger? Certainly. According to this site, 40,000 ppm (or 4%) is "immediately harmful due to oxygen deprivation." It also says that 5,000 ppm (0.5%) is the PEL for daily workplace exposures.
I agree they should point out the dangers of easily-repeatable demonstrations like this more clearly. They should have done the big one outside, at least. But it may not be as bad as it seems.

Finally, do I have a point? Not really. I just think it's fun to do ballpark calculations like these. I guess the takeaway here is that the answer to the question "Is this dangerous?" is a solid "Maybe"

Quote: Originally posted by MrHomeScientist

Luckily, your body also warns you about CO2 exposure so you'd have some indication that you should leave the area at least. So it's likely the danger is much less severe than it appears from the math.

Quote: Originally posted by MrHomeScientist

Let's consider the weights and volumes in play here. It's impossible to get exact measurements from a video, so there's a lot of guesswork and rounding going on, but bear with me. I also apologize for Imperial units! It looks like about an 8" pot filled with dry ice to about 3". That makes about 0.09 ft3 of dry ice (assuming a solid cylinder, which it's not, so this is high end). Density of dry ice is about 100 lb/ft3, so this is 9 lbs of dry ice. 1 lb of dry ice turns into about 8.3 ft3 of gas, so this would create 74.7 ft3 of CO2 (assuming it all instantly vaporized, which it doesn't, so again a high end estimate). A "standard" small kitchen is 10ft x 10ft, and their ceiling appears to be 8ft. Let's cut that in half to a 4ft height since we're concerned about children, so that's 400 ft3 of volume (assuming the kitchen is a completely enclosed space, which it clearly isn't since it's open to other rooms, making this again a worst-case scenario). Now let's look at two extremes, since we don't really know the extent and rate of mixing of these gases: Zero Mixing: Assuming the CO2 completely displaces the air with zero mixing, it would only fill the 10x10 kitchen up to 0.75ft with pure CO2, well below kid level unless they're laying on the floor. Perfect Mixing: Assuming it mixes perfectly with that 400 ft3 volume. Normal air is 0.04% CO2, which is 0.16 ft3 of gas. Adding that to the 74.7 ft3 of vaporized dry ice, and dividing by the 400 ft3 room volume we arrive at 18.7% carbon dioxide content. Reality: Somewhere in between these. There will be a concentration gradient, highest at the floor and decreasing with height. It certainly won't be 100% CO2 at the floor, as zero mixing would suggest. But is this number meaningless? Did I waste my time here? Perhaps! I certainly overestimated the amount of dry ice, and vastly underestimated the room size. You'd also need to consider the amount of time it takes to vaporize that quantity of ice, and the time for onset of symptoms to occur (the concentration wouldn't instantly become lethal as my analysis might suggest, and people wouldn't instantly pass out). Luckily, your body also warns you about CO2 exposure so you'd have some indication that you should leave the area at least. So it's likely the danger is much less severe than it appears from the math. Is there danger? Certainly. According to this site, 40,000 ppm (or 4%) is "immediately harmful due to oxygen deprivation." It also says that 5,000 ppm (0.5%) is the PEL for daily workplace exposures. I agree they should point out the dangers of easily-repeatable demonstrations like this more clearly. They should have done the big one outside, at least. But it may not be as bad as it seems. Finally, do I have a point? Not really. I just think it's fun to do ballpark calculations like these. I guess the takeaway here is that the answer to the question "Is this dangerous?" is a solid "Maybe"

Cookie well earned!

I have nothing more to say.. Have a good day, night - whatever you are having right now.

Quote: Originally posted by Herr Haber

From my personal experience I can testify that: - People will not worry when their cigarette extinguishes by itself - People will not worry when their joint extinguishes by itself - People will not notice their lighter is making a different long flame - People will get out of the room when the lighter doesnt work at all anymore and even then might not realize what was going on. Seen at a concert 30m below the earth so I'm a bit skeptical about this sense of danger we're supposed to have...

Actually, I believe the major reported instances of dying from the CO2 occurs when it fills ups holes and such, as apparently cave explorers do die from CO2 exposure being it is a heavy odorless and colorless gas (read this http://nhvss.org.au/wp-content/publications/CO2.htm ).

In a house, don't do the described experiment in a poorly ventilated basement, as that could likely turn into a death trap, especially for small children.

[Edited on 28-11-2018 by AJKOER]