Came to say precisely this. Before you run out of o2 the co2 levels will likely render you unconscious, and will potentially also suppress your breathing.
I took a lungful (choked on the first breath, coughed, started really choking) of air heavy with co2 in a pub cellar once. Only because I fainted on top of the kegs above the co2 saturated air on the floor (leaky cylinder valve) am I here to tell you about it. Tastes like acidic metal and black velvet rushes in.
There are also lakes which occasionally emit big bursts of CO₂. And, of course, it's denser than air, so you get an invisible flood of CO₂ pouring down the riverway... where people live. These can be thoroughly fatal.
Lake Nyos emitted a CO₂ cloud in 1986 which killed 1700 people.
Pure nitrogen is even more dangerous because it feels perfectly normal to breathe it. You have no idea anything is wrong until you pass out, which can happen very quickly. Kind of a nice way to go, actually.
An other fun danger of insufficiently aerated rooms: in wine countries, until cellars aeration became more widespread a huge danger was CO buildup in cellars from fermentation, to these days people regularly die during initial fermentation, and a warning you get is "if you see somebody unconscious at the bottom of the cellar stairs you do not go down to help, you call the firefighters, trying to help just ensures they have two bodies to retrieve".
So, horror movies are realistic for once. If you see your friend lying dead in the cellar... GTFO of there, it really is zombies (or gas buildup of some variety) . :)
There are, sadly, lots of reports of farmers and their family members dying in manure pits due to a buildup of CO2 and methane. Someone goes in first and passes out, and then anyone else who tries to go in to save him suffers the same fate. In one case 5 members of a dairy farming family all died trying to save their father.
That would work if you have excellent breath-holding ability. But since you're exerting yourself by carrying an ~150-lb body, there is a risk you'll pass out because you're holding your breath. So you probably should take multiple trips, repeatedly moving the person partially and then returning to get good air. You should _slowly_ exhale all the while.
DO NOT hyperventilate before holding your breath and exerting yourself! Reason is, if you hyperventilate, then take a big breath, hold it and exert yourself you are likely to pass out _instantly_ w/o warning! [This was something we learned as kids - do not do this! You _will_ pass out (and you also risk embolism/stroke).
"Why slowly exhale?" - So you don't increase the pressure in your lungs.
"Why is hyperventilating first bad?" - Should you hyperventilate and then hold your breath and any pressure is put on your lungs, YOU WILL PASS OUT! Don't do this!
Essentially hyperventilation reduces the blood's CO2 level. It becomes so low (while hyperventilating) that the body does not detect when the CO2 level subsequently rises to a dangerous level(while diving/holding your breath). The body fails to urge you to breathe fresh air and so you unwittingly pass out.
Deep-water divers hyperventilate and then take a big breath immediately before they dive. Sometimes "shallow water blackout" (same as what happens to kids in the "choking game) occurs, endangering the diver:
I've always been confused by this too - you'd think holding your breath would make it safe-ish.
I can only assume that it's still extremely risky because even if you remember to do it, you are very likely to misjudge how long you can hold your breath during an emergency situation with adrenaline pumping that requires you to drag someone up the stairs. Which means you get halfway up, end up forced to take a big deep breath, and pass out.
You could do that while lifting and carrying a 150 pound person up some stairs? Maybe if you had a rope with a slip knot, you could run down and put the rope around their body and run back up, then pull them up the stairs while trying not to hit their head on each step?
As others are saying - the CO2 poisoning will make you unconscious way before O2 runs out. You can train for it tho, much like freedivers do if you plan on surviving in airtight containers for longer periods of time.
I got my parents a NetAtmo device it has an outside thermometer but also one for inside that also has a CO2 detector. It's amazing how often just my two parents plus one cat in a 5mx5m living room will cause it to reach near 1000ppm.
At Christmas time with about eight people it easily hit 1000ppm very quickly. Nobody else knew but I was watching the readings and it was interesting to see how that point it seems stuffy so a window was opened for some fresh air.
This is a 1970s single floor bungalow with forced air heating but no air exchange.
I had a theory this was what caused me to feel really sleepy when attending lectures. Wasn't sure how to prove it, though of course it could make sense with the right figures plugged in.
This can be alleviated with the use of CO2 scrubbers[0]. Basically you fill fan-powered canisters with minerals ("sodasorb" is a popular product used in the offshore diving industry), which absorbs CO2 from the atmosphere. That's not to say that you need to be able to remove and replace the minerals in the scrubbers every so often.
Out of curiosity, do you have an idea of the typical delay before saturating the filter? Do you have some pointer to space suits specification or something like this that I could read to have more information?
According to Wikipedia, "One gram of anhydrous lithium hydroxide can remove 450cm³ of carbon dioxide gas."[1] Also according to Wikipedia, a person produces some 1kg of the gas a day [2], which translates to roughly 550000cm³. That means around 1.2kg of lithium hydroxide per day per person.
The Apollo 13 LM canisters were rated for some 56 hours for two persons, but could only support three for less than 35 hours. That seems to fall somewhere between 5 and 6 kilograms, and apparently includes the scrubbers of the space suits onboard. Each suit was designed to support life for 6 hours (+ 30 minutes of emergency reserves) [3] which means some 350 grams of lithium hydroxide.
The longest EVA thus far lasted for just under 9 hours [4], for which you would need a bit more than 450 grams of lithium hydroxide. The Russian Orlan suits are designed to support life for between 5 and 7 hours [5].
An astronaut on an EVA might produce more carbon dioxide than the Wikipedia approximation, so you might want to round those numbers up.
Edit: I am also not sure how close to the theoretical maximum that absorption capacity is, so the numbers might really be somewhat optimistic.
Arguably, that was THE critical issue for crew survival after the Apollo 13 incident leading to the famous 'jury-rigged' CO2 scrubbing device improvised by the engineers on the ground
'Availability of lithium hydroxide (LiOH) for removing carbon dioxide presented a serious problem.'[1]
On an unrelated note - I read your term 'jury-rigged' and was thouroughly confused for a good minute. It sounded right in my head, but reading it on paper (screen) it looked wrong. Except looking up 'jury rigged' led to results about... Juries being rigged. Eventually I realized that the term I was looking for is 'Jerry Rigged':
That's odd, the first two results for me when I search for jury rigged is a Google summary box with the definition and the Wikipedia article: https://en.wikipedia.org/wiki/Jury_rigging
Are you studying law or something, maybe Google is overly personalizing? :)
