I have a high-sensitivity CO detector.
Been reading 000 for years.
All of a sudden tonight, it went off at 15PPM.
House has been closed up tight all day.
I replaced the battery and moved it to another room.
Reading gradually went back to zero.
Furnace is off, but I turned off the gas anyway.
Don't have anything else that burns fuel.
So, I opened the windows, turned on the exhaust fan
and the reading went up.
So, took it outside and it reads 28PPM.
There's a light breeze, so any local source oughta dissipate??
I can't think of a detector failure mode that would
explain the readings.
I have two other standard-sensitivity CO detectors that
So, is 28PPM high for an outdoor reading?
Can't think of anything I could do about it anyway.
From a Matheson Gas MSDS:
50 ppm (55 mg/m3) OSHA TWA
35 ppm (40 mg/m3) OSHA TWA (vacated by 58 FR 35338, June 30, 1993)
200 ppm (229 mg/m3) OSHA ceiling (vacated by 58 FR 35338, June 30, 1993)
25 ppm ACGIH TWA
35 ppm (40 mg/m3) NIOSH recommended TWA 10 hour(s)
These are worker limits. Most companies would probably comply with the
lowest limits but OSHA would be the law.
Maybe your detector is off or maybe you live in a high traffic area.
It is my understanding that the main problem with CO is that it
PERMANENTLY bonds to the iron/hemoglobin, or such. Which translates to
removing those cells from carrying any oxygen. Which means post-
exposure can kill you. Takes time for the body to replace and get the
oxygenation system back up and running again. Heart patients are
I preferenced my statement with "It is my understanding..." to
indicate that the statement was based upon memory and not citable
scientific/medical literature. Actually based upon undergraduate
experience in a COLD climate and listening to the gossip after some
dating couple had succumbed to CO poisoning from an idling engine as
the couple said goodbyes [no pun intended] while inside a warm car.
From your reference:
"The goal of treatment for carbon monoxide poisoning is to remove
carbon monoxide from the hemoglobin in your blood and bring the oxygen
level in your blood back to normal." Evidently in the presence of
'pure' oxygen, the hemoglobin - CO bond can be broken.
The article did go on to say that hyperbaric pressure treatment was
All much safer than whole blood transfusions. But, I bet they work.
Relative safety depends on the severity of the CO poisoning and the
presence or absence of other medical problems. Patients with emphysema
or other significant lung abnormalities, or with "holes" in their hearts
(septal defects) are not good candidates for hyperbaric oxygen; massive
transfusion might be safer. In the absence of significant cardiac or
pulmonary pathology, hyperbaric treatment is much faster, easier,
cheaper, and safer than massive transfusion.
Isn't this a simple diffusion problem?
Hemoglobin is continuously releasing whatever it has and reattaching
to whatever is in the vicinity.
The relative concentrations and bond strengths determine the statistics
of the process.
If the CO bond is stronger and the half-life of releasing it is higher,
most of the available hemoglobin molecules would have previously
attached to CO2 or O2. If the air concentration of CO is high,
the probability of re-attaching to a CO molecule is higher.
If the "half-lives" of the bonds are significantly different
and there's any available CO in the air, things can go very
wrong very fast.
Oxygen therapy insures that any CO that is given up is not likely
to reattach to another hemoglobin and pushes the statistics
the other way.
How old is the detector? Some are done after 2 years. According to
When carbon monoxide detectors were introduced into the market, they had
a limited lifespan of 2 years. However technology developments have
increased this and many now advertise up to 7 years. Newer models are
designed to signal a need to be replaced after that time-span although
there are many instances of detectors operating far beyond this point.
Given that he has two other detectors that are silent and
the symptoms I would expect that it's a faulty detector.
He could check with that guy Holmes on TV. He seems
to have a fetish for CO. Every garage he goes into he
immediately declares it's not sealed sufficiently from the
rest of the house and how everyone is gonna die. He
says your car is gonna gas the whole place with CO
and kill the kids.
Seems much overdone to me. I don't know about Holmes, but my car
only runs with the garage door
wide open, the exhaust right at the door pointed out,
and for 15 secs or so.
And as someone else pointed out in another post a
while back, how much CO does a typical modern car
give off? With the catalytic converters and EPA
mandates, I would expect it's a small fraction of what
it was 40 years ago. Now, if you close the garage door
and run the car, that's another story.
On 5/15/2012 7:52 AM, email@example.com wrote:
once the modern vehicle is warmed up and the cat is "lit" off, you
probably couldn't get a reading out of a co detector even with the door
closed. You'll die from lack of o2 before dying of co. Now, a
lawnmower.... that's a different story. We could set off the co
detector in the shop i worked at in a matter of 2 minutes running a
lawnmower. Sometimes with the door open even.
remove the "not" from my address to email
I once bought a bag of CO. It was made to test CO detectors.
It was something like a single-serving ketchup bag. I bought it at a
hamfest and it was sort of beat up and probably old, but it still had
a bunch of gas in it.
He either had only one bag, or under ten.
I haven't seen it lately. I think I used it and it worked.
This is mistakenly titled C02, but the listing and the label on the
bottle says its CO gas:
12 bottles (or maybe cans) for 210 dollars. It doesn't say how big
the bottles are or indicate how many tests you can make with one.
20 years ago, I asked the customer service person if I could just move
my CO detector to the furnace room, where i figured it would find
some, and she said that would be bad for it if the CO level was really
I just light a kitchen match, a wooden one 2 inches long, and hold it
under the smoke detector. The one wired to the house still works
after 33 years**.. And it also went off recently when I overheated a
skillet with oil in it.
**( have newer battery operated ones too.
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