Does anyone know the lethal dosage of carbon monoxide?

[atakach]

35 ppm (0.0035%) Headache and dizziness within six to eight hours of constant exposure
100 ppm (0.01%) Slight headache in two to three hours
200 ppm (0.02%) Slight headache within two to three hours
400 ppm (0.04%) Frontal headache within one to two hours
1,600 ppm (0.16%) Dizziness, nausea, and convulsions within 45 minutes. Insensible within two hours.
3,200 ppm (0.32%) Headache, dizziness and nausea in five to ten minutes. Death within 30 minutes.
6,400 ppm (0.64%) Headache and dizziness in one to two minutes. Death in less than 20 minutes.
12,800 ppm (1.28%) Unconsciousness after 2-3 breaths. Death in less than three minutes.


Concentration Source
0.1 ppm Natural background atmosphere level (MOPITT)
0.5 to 5 ppm Average background level in homes[8]
5 to 15 ppm Levels near properly adjusted gas stoves in homes[8]
100 to 200 ppm Mexico City central area from automobiles[9]
5,000 ppm Chimney of a home wood fire[10]
7,000 ppm Undiluted warm car exhaust[10]
30,000 ppm Undiluted cigarette smoke[10]

I've had minor CO poisoning. It's not fun. #'s are from WIKI, so take them for what they are.

interesting, at saftey meetings we learned the osha standards. we had monitors in the coke ovens, which had a lower limit and upper limit, lower being set at i think 50ppm, and upper of 75ppm,

but osha said, below 100ppm, was safe for an 8 hour shift, since we worked 12 hrs, the set the limits lower......how nice of them


andrew

 

[WadeH]

Good point on that one -

"The CO binds with your hemogloblin instead of the O2. The hemogloblin likes it better thant the O2 so therefore it just stays there. So it just keeps building up until you are not getting any oxygen at all and you suffocate."


Question:
How long does it remain "there", with the hemoglobin?
Is it slowly "washed" out of your system over a day's time?

I was typing in a hurry, sorry, did not want to leave the impression that it never leaves. But Yes it is slowly washed out of your system. In the emergent setting we always put patients on high flow O2 on a nonrebreather mask to speed up the process. It is the building up of the CO that causes the increase of symptoms. That is why the symptoms increase in severity as the time of exposure increases. Hope that makes better sense.

 

[indy]

I've been wondering about that for a long time. Thanks, I always keep my garage doors open (2 doors) open at least 12" whenever I forge, no matter what the weather, I'd rather be cold than dead. Figure this how ya gonna get cold when your forge is operating at 1700oF or so.:jerkit:

That's pretty much how I ended up with CO poisoning. Working on a truck with the garage doors open about 3' when it was really really cold outside, no heater. Next day I woke up with a massive (think worst hangover ever) headache and feeling like I had a massive case of the flu. I called the guy who's garage we were in and he had the same thing. Took about a day to get rid of the headache, calling it lesson learned.

Best figured the extreme cold was making a strong thermal barrier, so even though the garage was open and exhaust pointed outside, it was actually trapping the gas in with us.

Now I keep a CO monitor mounted at head height whenever I'm running the propane.

 

[T Blade]

That's pretty much how I ended up with CO poisoning. Working on a truck with the garage doors open about 3' when it was really really cold outside, no heater. Next day I woke up with a massive (think worst hangover ever) headache and feeling like I had a massive case of the flu. I called the guy who's garage we were in and he had the same thing. Took about a day to get rid of the headache, calling it lesson learned.

Best figured the extreme cold was making a strong thermal barrier, so even though the garage was open and exhaust pointed outside, it was actually trapping the gas in with us.

Now I keep a CO monitor mounted at head height whenever I'm running the propane.

Indy,I too have had a similar incident. My work area is 20' X30', 2 standard size garage doors and one personnel door. I have a floor fan and a couple of shelf fans (inlet at the personnel door and outlet at the garage doors), this arrangement give very good air circulation. It would be nice to have a hood over my forges, but when in use they are usually in the middle of the garage.
Several years ago (before adding fans) while doing some ornimental iron I ended up with a slight case (I believe) of CO poisoning. I really had been wailing on some heavy pieces of steel/iron to make a couple of projects. I'd been at it for a few hours with the 2 garage doors open at about 12" and the personnel door open full. I did start to get a bit dizzy so I called it a day out in the garage/smithy. I don't know if it really was CO or just working too hard. Indy, you are absolutely correct though, I should have a CO detector out there.

 

[aggopian]

2 bay repair shop, 4 bay doors open (one on either side), 95 degrees dead air. My boss was working on an old corvette (new motor setting timing adjusting carb). Snap On man walked in and he turned to him and started talking but was only mumbling gibberish and looked confused. He ended up in an oxygen chamber but noone else in the shop had any serious symptoms or problems.

It appears that proximity, air quality and individual metabolism are factors.

Lesson learned we installed a detector.