Ok five years in the fire service and I can't get someone nailed down on Co Levels in a nonfire situation. Like on a CO check what level is to much. I know our SOPS for CO levels and SCBAs. I know that it effects children faster. But at what level do we vent the house and shut things down? Is any level of CO acceptable in the standerd home setting. Everyone I ask gives a different anwser. So I am asking everyone.
Most healthy adults will start experiencing syptoms of CO poisoning around 70 PPM if exposed for an extended period of time. The higher the PPM of CO then the more serious and quickly the symptoms will occur.
Vic is correct. OSHA's short term exposure limit (STEL) for CO is 50 parts per million (PPM). That's what they say is the most an adult can be exposed to averaged over a 15 minute period. Not sure about pediatric exposure.
Found on eMedicine: "The very young and very old are most susceptible to both exposure and the pernicious effects of carbon monoxide." They say the elderly are in the highest CO exposure incidence bracket, however.
Vic is correct. OSHA's short term exposure limit (STEL) for CO is 50 parts per million (PPM).
Norm, the OSHA link from Vic specifies a PEL of 50PPM, not a STEL.
If anyone reading this is a bit lost on TWA's, STEL's, PEL's and what they mean:
TWA-Time Weighted Average- based on an 8 hour day, 5 days per week (maximum 40 hours per week)
STEL-Short Term Exposure Limit- 4 exposures per day, maximum 15 minutes duration and a minimum of 1 hour break between exposures (must go to clean air)
PEL-Peak Exposure Limit- No more than 1 exposure of 15 minutes duration.
The TWA is what most CO meters use for the low alarm limits - at least in the U.S.
The low alarms are usually set to 35 PPM, the TWA. Remember that OSHA sets these limits for people unprotected by SCBA. If you wear SCBA, you can legally perform a rescue from a 1 million PPM environment, although that would almost certainly be a body recovery.
However, ANY concentration of CO in an enclosed area in a non-fire situation may be dangerous, especially if the CO source has not been identified and shut down.
Also, gasoline-powered equipment such as PPV fans can generate CO and inject it into a confined area like a house or confined space and actually INCREASE the CO level. That's why gasoline-powered fans should not be used for ventilation in a non-fire situation.
Our standard is the OSHA standard too, 50 ppm. There are plently of other nasty things in the air after a fire that we should also be worried about. We have gone to filter cartridges after SCBA's come off at 50 ppm CO for overhaul.
National Occupational Health and Safety Commission (NOHSC):
TWA (eight-hour time weighted average) exposure limit in the workplace: 30 ppm (34 mg/m³).
There is not a conventional short-term (15 minutes) exposure limit (STEL) for carbon monoxide. However, guidelines for the control of short-term excursions for carbon monoxide have been established by the NOHSC. They are: