Emergency Procedures
CO alarm response protocols, building evacuation procedures, emergency ventilation techniques, equipment shutdown sequences, and technician responsibilities when dangerous CO levels are discovered.
- Execute the correct response sequence when a CO alarm activates or dangerous CO levels are detected
- Determine when to evacuate occupants based on CO concentration thresholds and exposure duration
- Perform emergency ventilation and equipment shutdown to reduce CO levels before diagnostic testing
- Document emergency CO events and communicate findings to occupants and authorities
Leçon 1
CO Alarm Response and Evacuation Protocols
When CO Is Detected
Discovering elevated CO during a routine combustion safety inspection requires a different response than discovering it during an emergency call. In both cases, the technician's first priority is occupant safety, but the urgency and sequence of actions depend on the CO concentration and the presence of symptoms.
The NCI protocol establishes clear action levels based on ambient air CO concentration:
0-9 ppm ambient CO: Normal range. No immediate action required, but if indoor levels are consistently above 5 ppm, investigate potential sources including attached garages, outdoor sources, or minor combustion equipment issues.
9-35 ppm ambient CO: Investigation threshold. The CO level exceeds the outdoor ambient standard and indicates combustion products are entering the occupied space. Inform the occupants. Begin systematic testing of all combustion equipment to identify the source. Increase ventilation by opening windows if weather permits.
35-70 ppm ambient CO: Alert level. The NIOSH REL (35 ppm) and the OSHA PEL (50 ppm) have been reached or exceeded. Immediately inform all occupants. Open windows and doors to ventilate the space. Identify and shut down the suspected source appliance. If occupants report symptoms (headache, nausea, dizziness), recommend they move outdoors and seek medical attention.
70-200 ppm ambient CO: Evacuation level. Immediately evacuate all occupants from the building. Open windows and doors for ventilation on the way out. Do not re-enter until CO levels have been reduced below 9 ppm and the source has been identified and corrected. If occupants show symptoms, call emergency medical services.
200+ ppm ambient CO: Emergency level - this exceeds the NIOSH ceiling. Evacuate immediately. Call 911. Do not re-enter without self-contained breathing apparatus (SCBA). This concentration can cause loss of consciousness within 2-3 hours and death with prolonged exposure.
Recognizing CO Poisoning Symptoms
CO poisoning symptoms progress with concentration and exposure duration. Technicians must recognize these symptoms in building occupants and in themselves:
| CO Level (ppm) | Exposure Time | Symptoms |
|---|---|---|
| 35-50 | 8+ hours | Headache, fatigue in healthy adults |
| 100 | 1-2 hours | Headache, slight nausea |
| 200 | 2-3 hours | Severe headache, dizziness, impaired judgment |
| 400 | 1-2 hours | Confusion, nausea, life-threatening |
| 800 | 45 minutes | Convulsions, unconsciousness |
| 1,600 | 20 minutes | Death |
| 6,400 | 1-2 minutes | Death |
CO is often called the "great imitator" because early symptoms (headache, nausea, fatigue, dizziness) mimic the flu, food poisoning, and other common illnesses. A key diagnostic clue is that symptoms improve when the person leaves the building and return when they re-enter. If multiple occupants have the same symptoms simultaneously, CO poisoning should be suspected.
Protect Yourself First
If you feel headache, dizziness, or nausea during a combustion inspection, leave the building immediately. Your personal CO monitor should alarm before symptoms develop - if it alarms, evacuate without hesitation. A technician who becomes incapacitated cannot help the occupants. Your safety comes first.
The Personal CO Monitor
Every NCI technician should wear a personal CO monitor clipped to their collar or chest pocket during every combustion safety inspection. The personal monitor provides continuous low-level CO detection at the technician's breathing zone.
Personal monitors typically alarm at:
- 25 ppm TWA (time-weighted average alarm)
- 50 ppm instantaneous (low alarm)
- 100 ppm instantaneous (high alarm)
The personal monitor serves as a backup to the combustion analyzer. While the analyzer measures CO at the probe tip (which may be in the flue or at a specific test point), the personal monitor measures the air the technician is actually breathing.
The CO action levels are: 9 ppm (investigate), 35-50 ppm (alert occupants and ventilate - NIOSH REL at 35 ppm, OSHA PEL at 50 ppm), 70 ppm (evacuate), and 200 ppm (emergency - call 911). CO symptoms mimic the flu - if multiple occupants have headaches that improve when they leave the building, suspect CO. Always wear a personal CO monitor during combustion inspections.