All I can find is the Occupational Exposure Limit given by the HSE. They have an 8 hr figure of 0.5%. This is presumably the limit deemed to be safe in the workplace, maintained over an entire shift.
The test results in their experiments ranged from 0.63 to 1.54%.
Which would make a lot more sense as "..., and you will NOT be fine" :-(
CO2 isn't toxic inthat it will kill you by poisoning, it may kill you via the non-presence of oxygen but it's not toxic like carbon monoxide, I think this is all getting pedantic now anyway, we breath carbon dioxide every day from our birth to our deaths, if it was poisonous we wouldn't live very long. Carbon monoxide is poisonous and worse still it has cumulative effects, meaning that levels of it can build up in the bloodstream for weeks, months or even years unnoticed until one day it reaches the point where it causes death.
|Dave Fawthrop wrote: |>
|> Not me Wikipedia, or Google will get you lots of other URLs saying |> the same things. | |CO2 isn't toxic inthat it will kill you by poisoning, it may kill you via |the non-presence of oxygen but it's not toxic like carbon monoxide, I think |this is all getting pedantic now anyway, we breath carbon dioxide every day |from our birth to our deaths, if it was poisonous we wouldn't live very |long.
Some people should learn to use Google, and read what they find
This is sometimes known as choke damp, an old mining industry term, and was the cause of death at Lake Nyos in Cameroon, where an upwelling of CO2-laden lake water in 1986 covered a wide area in a blanket of the gas, killing nearly 2000.
Hemoglobin, the main oxygen-carrying molecule in red blood cells, can carry both oxygen and carbon dioxide, although in quite different ways. The decreased binding to oxygen in the blood due to increased carbon dioxide levels is known as the Haldane Effect, and is important in the transport of carbon dioxide from the tissues to the lungs. Conversely, a rise in the partial pressure of CO2 or a lower pH will cause offloading of oxygen from hemoglobin. This is known as the Bohr Effect.
doesn't live in a dissused mine in outer mongolia, he lives in a house, the CO2 levels cannot get that high under these circumstances otherwise how would anyone *ever* die of monoxide poisoning?
I don't know why you are seeking glory with this, you are just making yourself look foolish....AFWIW, Wiki is written by anyone, I could go and edit any page right now to prove any point I like, primary schoolkids know that we breath CO2 every day and it's not toxic, if it was there wouldn't be any need for primary schools because we wouldn't be here.
Yes they typically specify a huge amount of permanent purpose provided ventilation (100cm^2) and large minimum room size. (40m^3) The more powerful models may regire an even bigger room.
The problem is not pedanticism. The problem is that the statement "CO2 is not toxic" is false. It is toxic. It is not displacement of oxygen that causes this toxicity. It is only toxic in concentrations that are unlikely to occur in a domestic setting.
You call being correct pedantic. However, others can't allow such a false statement to continue unchallenged.
Christian.
Toxic means it poisons you, so if we all have it around us all the time, how do we manage to live for 70 years? - why does it not kill us slowly like lead or other elements?
It is only toxic in concentrations
Which is what we were talking about....and the pedantics started creeping in around here.
Because they're being pedantic...everything is toxic *given the right volumes and concentrations* - it was obvious to anyone with even half a degree of common sense that it was to this room, with the unvented gas fire inside it that I was referring, unless I'm expected to end each sentence with, "in the context of this room, with the unvented gas fire inside it"
AIUI there are at least two aspect to toxicity. How much (or what concentration) will kill you in a given short time. How much can you be exposed to regularly and have no long term ill effects.
I believe that CO2 needs something around 15% plus in air to kill you in hours. (IIRC the concentrations in Apollo 13 got over 10% before they managed to get the LiOH filters working.)
Clearly exposure values of less than 0.5% are both unavoidable and inconsequential.
I'm informed that 4000ppm of CO is fatal in minutes. The safe exposure limit is 50ppm.
AIUI even water has a toxicity (IIRC something like 10 litres in less than
60minutes is fatal).
So there's no possibility of carbon dioxide killing people in a domestic house, with an unvented gas fire? - pretty much what I said. Even the tests on them have proven that it doesn't get anywehere close to the 'permitted levels' boundary.
No-one disagreed with that. It was the blanket statement that CO2 is non-toxic that was being objected to.
Christian.
CO2 can be toxic with fire extinguishers. An (large) excess affects breathing, even in the presence of enough oxygen.
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