Similarly, the small block of solid can produce enough CO2 to fill your car or tent, and at worst kill you dead, and at the other worst make you so sleepy that you have an accident. Don't store the cooler in your tent, ventilate your car.
As this was an experiment, I'd be interested in how you ascertained the section in red I highlighted. Who volunteered?
Alas, I had no volunteers to test that statement. I didn’t test the exploding cooler statement either, so that is available for verification. I think I’ll leave that one to the MythBusters.
Although I didn’t test the statement directly, I have every reason to believe it is a valid conclusion, based on my observations. When the dry ice was in the cooler, I could feel cold “air” leaking out of the closed drainage valve. I know the CO2 was sublimating and expanding, causing an overpressure in the cooler. I know that CO2 is heavier than air and without mixing would sink to the lowest point. Therefore, this was most likely CO2 leaking out of the valve. It was a surprising amount, like the feeling of holding your hand in front of your mouth and blowing gently.
I had always assumed that you died of CO2 exposure because you used up all the oxygen in an inclosed space, or the CO2 displaced the oxygen, causing suffocation - death from lack of oxygen. Surprisingly (to me at least,) this isn’t always how it happens. It turns out that CO2 itself is actually toxic, and can harm or kill you even when there is enough oxygen in the air.
1,000,000 ppm of a gas = 100% concentration of the gas. Therefore, 10,000 ppm of a gas in air is a 1% concentration.
Normal outdoor CO2 concentration is between 300 and 400 ppm. 400 ppm is a 0.04% concentration.
Indoor air usually has about 600 ppm, or a 0.06% concentration.
At 1% concentration of CO2, some people may begin to feel drowsy. This can happen in a room full of people with poor ventilation. These effects are most likely from the reduction in the amount of oxygen.
At above 5%, CO2 is directly toxic.
I found a few sources that explain it much better than I can.
This case study is very interesting, dealing with the death of a man who went into a walk-in refrigerator containing dry ice in which the ventilation system had failed. http://www.emedmag.com/html/pre/tox/0500.asp
And this site also explains it very well:http://www.inspectapedia.com/hazmat/CO2gashaz.htm
So, the question is, when I throw my cooler in the back of the Lexus, set the AC to recirculate and hit the road for 10 hours, am I in danger? From the volume of CO2 that was being forced out of the valve it certainly seems likely that the CO2 concentration could easily climb into the 1% range, causing drowsiness. Could it climb higher into the range where the CO2 becomes toxic and kills quickly? Possibly, but like I said I didn’t do that experiment and I don’t think I will.
But thanks for asking
We will definitely be taking dry ice in the cooler, its so much less mess than water ice, lasts longer and is just as easy to get. We'll just make sure we have enough ventilation.
http://totheburn.posterous.com/ The story of two burgins who think they know what they are talking about.