Is dry ice poisonous

Answer 1

Dry ice is solid carbon dioxide (CO2). Humans exhale CO2 as a byproduct of the body combining oxygen breathed in and carbon from food, so breathing some CO2 is not. However, breathing only CO2 for any more than a minute or two deprives the body of oxygen, so yes, you can die from this. Also, dry ice is -109 degrees F or colder, so if you want to include thermal damage as poison, then that's another way dry ice is much more dangerous.

Answer 2

Dry ice is very cold, and it will damage any tissue it comes into contact with, so yes - dry ice is harmful to your lungs. However, you are probably asking about the gas generated as dry ice evaporates. That gas is Carbon Dioxide. As such, it is not harmful to your lungs, but you need to consider that you need Oxygen to survive - about 21%. (Although that gas may also be cold, so there might be an effect there as well.) If that Carbon Dioxide is displacing Oxygen, you will not be able to maintain conscienceness. Persist that beyond a short period of time, and you will die. This is an issue in rooms (Computer Centers, etc.) with Carbon Dioxide Fire Suppression. Since Carbon Dioxide is (in this case) intended to displace Oxygen, so as to put out the fire, you will certainly lose conscienceness and die if you do not leave immediately, i.e. when the pre-release alarm goes off.