On May 15, 3:48*am, Frank wrote:
On 5/15/2012 5:50 AM, mike wrote:





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
remain silent.

So, is 28PPM high for an outdoor reading?
Can't think of anything I could do about it anyway.

*From a Matheson Gas MSDS:

EXPOSURE LIMITS:
CARBON MONOXIDE:
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
REALLY sensitive.