The Importance of CO₂ Monitoring and Detection

Carbon dioxide (CO₂) is commonly used in various industries, including beverage dispensing, brewing, and increasingly in cannabis cultivation, where it is essential for optimising plant growth. However, CO₂ also poses significant risks to human health and safety when not properly managed. In enclosed spaces, high concentrations of CO₂ can lead to suffocation or even death. As a result, specific regulations have been implemented across the United States to ensure that CO₂ levels are properly monitored and controlled.

This guide provides an overview of the International Fire Code related to CO₂ monitoring and detection, explains the historical context behind these regulations, and highlights key considerations for ensuring compliance, including state-specific differences and the challenges of spurious alarms.

Historical Context: Why CO₂ Monitoring Regulations Were Introduced

Historically, CO₂ was primarily associated with the beverage industry, where it was used in carbonating drinks. However, the expansion of CO₂ use in other sectors, particularly in cannabis cultivation, has led to a growing awareness of the potential dangers associated with this gas.

Key Events Leading to Regulation Changes

1. Tragic Incidents:
   • Over the years, several fatal incidents involving CO₂ leaks have occurred, particularly in poorly ventilated spaces such as basements and enclosed storage areas. These incidents highlighted the need for code ordinances for CO₂ detection to prevent risk to life. For example, a well-known incident occurred in 2011 when a restaurant worker in Phoenix, Arizona, died due to a CO₂ leak in the soda machine storage room. This and similar events prompted a review of safety practices and led to more robust regulations.
2. Increased Use in Cannabis Cultivation:
   • The legalisation of cannabis in various states has driven the growth of indoor cultivation facilities, where CO₂ is often used to enhance plant growth. The increased use -enrichment- of CO₂ in these environments has raised concerns about potential leaks and the associated risks to workers’ health. This has necessitated updates to the fire code to address the specific needs of this industry.
3. Fire Department Callouts and Spurious Alarms:
   • As CO₂ monitoring systems became more common, fire departments began receiving an increased number of callouts due to CO₂ alarms. In many cases, these alarms were triggered by false positives or spurious alarms, often caused by improper calibration or lack of understanding about incremental alarms. These false alarms have led to unnecessary emergency responses, prompting a review of monitoring technology and practices to minimise such occurrences.

Understanding the International Fire Code for CO₂ Monitoring

The International Fire Code sets forth requirements for CO₂ monitoring and detection in commercial and industrial settings. These regulations are designed to protect both workers and the public from the dangers of CO₂ exposure.

Key Aspects of the International Fire Code for CO₂ Monitoring

1. Permissible Exposure Limits (PELs):
   • OSHA sets the permissible exposure limit for CO₂ at 5,000 ppm (parts per million) over an 8-hour workday. The International Fire Code requires that CO₂ monitoring systems be capable of detecting levels that approach this threshold to prevent dangerous exposure.
2. Alarm Thresholds:
   • CO₂ monitoring systems must be equipped with alarms that activate at specific thresholds:
     • 5,000 ppm (AL1): Investigate The first alarm level typically triggers a warning to take corrective action.
     • 15,000 ppm (AL2): Ventilate: Alarm 2 is a notification to try and disperse the CO2 if possible 
     • 30,000 ppm (AL3): Evacuate At this level, continue ventilation if possible but immediate evacuation is required, and emergency services must be notified.
   • Systems must be capable of automatically shutting off CO₂ supplies and activating ventilation systems when threshold levels are detected.
     
     

     *These alarm levels may differ globally and so you will still always want to check against your local requirements and adjust if required. 

     *Please note and where possible ensure sufficient training to staff to take notice of the alarm points. This prevents unnecessary call ours from the Fire Brigades for Alarm Level 3 only.

3. Monitoring and Detection Equipment:
   • CO₂ detectors must be installed in areas where CO₂ is stored, used, or produced. These detectors should be positioned at locations where CO₂ is most likely to accumulate, such as low points in the room, given that CO₂ is denser than air.
   • Detectors must be connected to an audible and visual alarm system that alerts occupants and emergency personnel of high CO₂ levels.
4. Backup Power and Redundancy (Recommended):
   • Monitoring systems should ideally have backup power supplies to ensure continued operation during a power outage. This is important to maintaining safety in the event of a system failure or emergency.

State-Specific Differences in CO₂ Monitoring Regulations

While the International Fire Code provides a national framework, individual states may have additional requirements or variations based on local conditions and industries. Here are some examples:

1. California:
   • California has specific stringent CO₂ monitoring requirements, particularly for the cannabis industry. The state mandates that all indoor cultivation facilities have continuous CO₂ monitoring systems capable of automatic shutoff in the event of a leak. This is in addition to the standard fire code requirements.
2. Colorado:
   • Colorado, another state with a significant cannabis industry, requires that CO₂ detectors be installed in both cultivation and extraction facilities. The state also mandates regular testing of these systems to prevent false alarms and ensure accuracy.
3. Oklahoma:
   • Oklahoma has adopted the International Fire Code (IFC) with specific amendments related to CO₂ monitoring. The state requires that CO₂ systems be equipped with telemetry capabilities that allow remote monitoring and notification to local fire departments in case of an emergency.
4. New York:
   In New York, CO₂ monitoring requirements are more focused on the food and beverage industry, reflecting the state’s significant restaurant sector. The state mandates that CO₂ detectors be installed in all locations where compressed CO₂ is stored or used, including restaurant soda systems and enclosed cold storage areas that have CO2 piped into them.

Challenges and Best Practices: Addressing Spurious Alarms and Ensuring Compliance

While CO₂ monitoring is essential, it can also present challenges, particularly in preventing false alarms and ensuring accurate detection. Here are some best practices to help manage these challenges:

1. Functional Testing: Regular checking of a system to ensure it is working appropriately and adjustment of any sensor drifts accordingly.
2. Regular Calibration and Maintenance:
   • CO₂ detectors should be maintained to prevent false alarms. Annual calibration against a specific known gas source ensures that sensors remain accurate and responsive to actual CO₂ levels.
3. Proper Installation:
   • Ensure that CO₂ detectors are installed according to manufacturer guidelines and in locations where CO₂ is most likely to accumulate. This can help reduce the likelihood of spurious alarms.
4. Employee Training:
   • Employees should be trained on how to take corrective action to CO₂ alarms, including evacuation procedures and how to safely shut off CO₂ supplies if necessary. Proper training can help prevent panic and ensure a coordinated response to any emergency.
5. Use of Advanced Monitoring Systems:
   • Ensure your CO₂ monitoring systems are correctly ranged for both control and safety. Typical CO₂ controllers are often limited to 2% (20,000 ppm), designed for plant growth optimization, whereas safety systems should be ranged up to 5% (50,000 ppm) for accurate hazard detection. Misusing these systems—such as expecting a control sensor to manage safety—can lead to spurious alarms and unnecessary fire department callouts.

Conclusion: Ensuring Safety and Compliance with CO₂ Monitoring

Compliance with the International Fire Code for CO₂ monitoring and detection is not just about following regulations—it’s about protecting lives. Proper installation, Regular testing and training in taking corrective action will help you avoid spurious alarms and keep your operations running smoothly and safely.

For more detailed guidance on how to implement a compliant CO₂ monitoring system, or if you have specific questions related to your state’s regulations please contact us to discuss.