The CO2 monitoring systems are designed to trigger alerts at three key concentration levels to ensure safety and regulatory compliance:
1. 500 ppm (Parts Per Million) – Ventilation Alert
This is an early warning level. It serves as a reminder that CO2 is beginning to accumulate in the space, often due to limited ventilation. While not hazardous, this alert helps facilities take proactive steps to improve airflow and avoid buildup.
2. 1500 ppm – Warning Level
At this point, CO2 levels are elevated and may begin to affect individuals with sensitivity to indoor air quality. Prolonged exposure could cause minor symptoms like drowsiness or headaches. This alert indicates that immediate ventilation or corrective action should be taken.
3. 3000 ppm – Danger Level / Emergency Alarm
This is a critical threshold. At 3000 ppm, CO2 levels are considered unsafe. Prolonged exposure can lead to more serious symptoms such as shortness of breath, dizziness, or impaired thinking. The system will trigger an audible and visual alarm to prompt immediate evacuation and corrective action.
Each level is configured to ensure the safety of personnel and compliance with local codes and OSHA/Fire Department guidelines.
Just to clarify, the 500 ppm, 1500 ppm, and 3000 ppm levels represent Time Weighted Averages (TWA)—which means the system monitors the average CO2 concentration over a period of time (usually 8 hours) rather than instant spikes. This ensures alarms are based on sustained exposure levels, which aligns with OSHA and fire code safety standards.
To clarify how the CO2 monitoring display works:
• The percentages shown on the left side of the display (0.5%, 1.5%, and 3.0%) represent real-time CO2 concentrations in the air. These are live readings measured continuously by the sensor. When the air reaches these levels—equal to 5,000 ppm, 15,000 ppm, and 30,000 ppm—the system triggers immediate alerts, signaling a potential hazard that requires urgent attention.
• The ppm values on the right side of the display (500 ppm, 1500 ppm, and 3000 ppm) represent Time Weighted Averages (TWA). These measure the average CO2 exposure over an 8-hour period. Unlike the live readings, TWAs help track prolonged exposure and ensure compliance with OSHA and fire safety regulations. Alarms at these levels are triggered based on sustained elevated CO2 over time rather than instant spikes.
Together, these dual readings provide both immediate protection from sudden CO2 leaks and long-term exposure monitoring for health and code compliance.
Here is what happens at each CO2 alarm threshold:
• 0.5% (5000 ppm or 500 ppm TWA) – This triggers a local alert only. The CO2 monitor will beep at the device, but no strobes or horns will activate, and there is no notification to the fire panel or monitoring company at this level. It simply alerts nearby personnel to rising CO2 levels.
• 1.5% (15,000 ppm or 1500 ppm TWA) – At this stage, the strobe will flash, and the CO2 monitor will continue to beep locally. In addition, the fire panel is notified, which in turn notifies the monitoring company, and they will contact the client. This is considered a serious warning level.
• 3.0% (30,000 ppm or 3000 ppm TWA) – This is the emergency alarm level. The fire panel activates all building horn/strobes with the intent to evacuate. At this point, the fire department is automatically dispatched to the site through the monitoring company.
These escalation stages are designed to provide early warnings, prompt response coordination, and full emergency evacuation if necessary.
This short video also provides some basic information on CO2 monitoring if you are interested:
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