Our current understanding is that no amount of CO2 is dangerous as long as everything else is fine, but in reality CO2 acts like the canary in the coal mine. When it climbs, it shows accumulation of stuff you don't want to deal with.
Measurement of compounds is best done using a monitor like Aranet, but incidental bumps in different values don't mean much. Long trends matter. If Radon is an issue in your region, a detector for that. Mold testing kits are readily available in market indicating moisture issues and you can get lead and other hazmat testing done diy/professionally
You say, "Our current understanding is that no amount of CO2 is dangerous as long as everything else is fine," but I don't think that is correct. Like any other non-oxygen gas, carbon dioxide is an asphyxiant, and it is routinely used as such to kill rats, but it has significant toxicity even at much lower levels. NIOSH says:
> Signs of intoxication have been produced by a 30-minute exposure at 50,000 ppm [Aero 1953], and a few minutes exposure at 70,000 to 100,000 ppm produces unconsciousness [Flury and Zernik 1931]. It has been reported that submarine personnel exposed continuously at 30,000 ppm were only slightly affected, provided the oxygen content of the air was maintained at normal concentrations [Schaefer 1951]. It has been reported that 100,000 ppm is the atmospheric concentration immediately dangerous to life [AIHA 1971] and that exposure to 100,000 ppm for only a few minutes can cause loss of consciousness [Hunter 1975].
100,000 ppm is 10%, so at that point the carbon dioxide has reduced the oxygen in your air from 21% to 19%, far from asphyxiation conditions.
Even at much lower levels, carbon dioxide can produce drowsiness and mental impairment.
On the other hand, reaching 5% or 10% carbon dioxide by oxidizing carbon with oxygen from the air, for example by breathing or having a fire, will reduce the oxygen content of the air to an extent that is more dangerous than the carbon monoxide. So carbon dioxide toxicity is generally not the thing to worry about with respect to indoor air safety. But that doesn't mean it's not real.
It's good to keep in mind that in your home the CO2 usually ranges from 400ppm to say 2,000 ppm. Getting to something like 100,000 ppm is not really plausible for a typical home. I get how in a submarine the conditions are different.
The point is that in the scenarios you described CO2 increases at the cost of oxygen, which is obviously not good, and that's what GP was referring to as "everything else is fine". It would be interesting to see what happens if instead some of the nitrogen in the air is replaced by CO2. But that's obviously not what usually happens. And there are far more damaging air contents to worry about. Like mold spores.
A crucial difference to CO is that CO2 doesn't cause permanent damage as long as oxygen supply is restored in time. Compared to that, hemoglobine touched by CO becomes essentially useless for the body since CO has a similarly high binding affinity to hemoglobin as oxygen. Recovering from that pretty much requires replacing the affected red blood cells.
Aren't there several studies showing markedly worse performance at tasks at CO2 levels easily reached in a home? Or you just mean you won't die as the meaning of not dangerous?
Studies have shown correlation with CO2 levels and performance but pinpointing the effect to CO2 alone hasn't been established. In fact, CO2's presence chemically helps with the oxygenation of the blood.
CO2 is an indicator. I don't let it climb in my home, and you shouldn't either. The problem is when people fixate on the CO2 levels. For example, you paint your walls with high VOC compounds, your flooring/furniture off-gas a lot, your vacuum cleaner doesn't have the proper filtration but you don't recognize your issues because your CO2 monitor shows 700ppm. That 700ppm can be a lot worse than a 700ppm your see in a home that has all of those considered.
People seem fixated on measuring CO2 specifically and often purchase expensive sensors ($$+) or devices ($$$) to measure CO2 levels.
There are inexpensive sensors ($) that detect a variety of VOCs but cannot distinguish between them and CO2. They'll never give you exact concentrations but they are consistent, broad spectrum, and will alert you of change. IMO these are a better option.
I don't get why they're so expensive. You can buy the ndir co2 sensor on AliExpress for around $10. And yet they want $180 for that thing. And measuring humidity and barometric pressure is a component that costs $4 or $5 for you or I to buy.
They’re not using a $10 sensor. They’re being very careful which $40 sensor they use. And they’re calibrating the rest of the device to produce an accurate reading across its range.
Quality CO₂ sensors are pricey. I previously had two from AliExpress, but both were unreliable and eventually broke. I finally got an Aranet4, and it’s been flawless for over a year so far.
Both particle measures and co2 sensors are somewhat affordable especially if buying raw sensors.
The up shot of it is ventilate frequently and dry heat cooking that browns anything (think steak in pan) releases a shit ton of particle so hood and open window
Our current understanding is that no amount of CO2 is dangerous as long as everything else is fine, but in reality CO2 acts like the canary in the coal mine. When it climbs, it shows accumulation of stuff you don't want to deal with.
Measurement of compounds is best done using a monitor like Aranet, but incidental bumps in different values don't mean much. Long trends matter. If Radon is an issue in your region, a detector for that. Mold testing kits are readily available in market indicating moisture issues and you can get lead and other hazmat testing done diy/professionally
You say, "Our current understanding is that no amount of CO2 is dangerous as long as everything else is fine," but I don't think that is correct. Like any other non-oxygen gas, carbon dioxide is an asphyxiant, and it is routinely used as such to kill rats, but it has significant toxicity even at much lower levels. NIOSH says:
> Signs of intoxication have been produced by a 30-minute exposure at 50,000 ppm [Aero 1953], and a few minutes exposure at 70,000 to 100,000 ppm produces unconsciousness [Flury and Zernik 1931]. It has been reported that submarine personnel exposed continuously at 30,000 ppm were only slightly affected, provided the oxygen content of the air was maintained at normal concentrations [Schaefer 1951]. It has been reported that 100,000 ppm is the atmospheric concentration immediately dangerous to life [AIHA 1971] and that exposure to 100,000 ppm for only a few minutes can cause loss of consciousness [Hunter 1975].
(https://www.cdc.gov/niosh/idlh/124389.html)
100,000 ppm is 10%, so at that point the carbon dioxide has reduced the oxygen in your air from 21% to 19%, far from asphyxiation conditions.
Even at much lower levels, carbon dioxide can produce drowsiness and mental impairment.
On the other hand, reaching 5% or 10% carbon dioxide by oxidizing carbon with oxygen from the air, for example by breathing or having a fire, will reduce the oxygen content of the air to an extent that is more dangerous than the carbon monoxide. So carbon dioxide toxicity is generally not the thing to worry about with respect to indoor air safety. But that doesn't mean it's not real.
It's good to keep in mind that in your home the CO2 usually ranges from 400ppm to say 2,000 ppm. Getting to something like 100,000 ppm is not really plausible for a typical home. I get how in a submarine the conditions are different.
From 9:50 onwards of this video explains what I meant: https://youtu.be/CkGDN85I29U?t=590
The point is that in the scenarios you described CO2 increases at the cost of oxygen, which is obviously not good, and that's what GP was referring to as "everything else is fine". It would be interesting to see what happens if instead some of the nitrogen in the air is replaced by CO2. But that's obviously not what usually happens. And there are far more damaging air contents to worry about. Like mold spores.
A crucial difference to CO is that CO2 doesn't cause permanent damage as long as oxygen supply is restored in time. Compared to that, hemoglobine touched by CO becomes essentially useless for the body since CO has a similarly high binding affinity to hemoglobin as oxygen. Recovering from that pretty much requires replacing the affected red blood cells.
1 reply →
Aren't there several studies showing markedly worse performance at tasks at CO2 levels easily reached in a home? Or you just mean you won't die as the meaning of not dangerous?
Studies have shown correlation with CO2 levels and performance but pinpointing the effect to CO2 alone hasn't been established. In fact, CO2's presence chemically helps with the oxygenation of the blood.
CO2 is an indicator. I don't let it climb in my home, and you shouldn't either. The problem is when people fixate on the CO2 levels. For example, you paint your walls with high VOC compounds, your flooring/furniture off-gas a lot, your vacuum cleaner doesn't have the proper filtration but you don't recognize your issues because your CO2 monitor shows 700ppm. That 700ppm can be a lot worse than a 700ppm your see in a home that has all of those considered.
Buy an air quality monitor. There are tons on Amazon. Here’s an example: https://www.amazon.com/dp/B0DZHJSQ7Z/
People seem fixated on measuring CO2 specifically and often purchase expensive sensors ($$+) or devices ($$$) to measure CO2 levels.
There are inexpensive sensors ($) that detect a variety of VOCs but cannot distinguish between them and CO2. They'll never give you exact concentrations but they are consistent, broad spectrum, and will alert you of change. IMO these are a better option.
I'ver heard the Aranet4 is quite good for this but haven't yet been able to justify buying one. I do try to open windows frequently, though.
I don't get why they're so expensive. You can buy the ndir co2 sensor on AliExpress for around $10. And yet they want $180 for that thing. And measuring humidity and barometric pressure is a component that costs $4 or $5 for you or I to buy.
They’re not using a $10 sensor. They’re being very careful which $40 sensor they use. And they’re calibrating the rest of the device to produce an accurate reading across its range.
Quality CO₂ sensors are pricey. I previously had two from AliExpress, but both were unreliable and eventually broke. I finally got an Aranet4, and it’s been flawless for over a year so far.
Both particle measures and co2 sensors are somewhat affordable especially if buying raw sensors.
The up shot of it is ventilate frequently and dry heat cooking that browns anything (think steak in pan) releases a shit ton of particle so hood and open window
Measure VOCs, PM2.5 particles, and CO2