Indoor air quality (IAQ) continues to be a critical focus for building managers, employers, and health and safety professionals, especially as we learn more about how air circulation impacts human health and disease transmission. On February 12, 2025, ASHRAE released its updated Position Document on Indoor Carbon Dioxide, reinforcing CO₂ monitoring as a practical tool for evaluating ventilation and indoor air quality (IAQ) — while also issuing a caution about its limitations.
Indoor CO₂ concentrations have long been used as a proxy for ventilation effectiveness, particularly in densely occupied spaces. Elevated levels often indicate inadequate air exchange and can prompt investigations into HVAC performance, especially in the context of airborne disease transmission and occupant comfort.
ASHRAE affirms that CO₂ measurements remain a useful indicator when used properly but emphasizes that they do not directly measure pollutant levels or infection risk. CO₂ is one variable among many and should be interpreted in conjunction with other IAQ parameters for a more complete picture.
The SGS Approach to Reliable CO₂ Monitoring
At SGS North America, we support IAQ programs with high-accuracy, real-time CO₂ instrumentation designed for professional environmental assessments. These tools provide dependable data to:
- Evaluate ventilation adequacy in occupied spaces
- Identify areas with insufficient air exchange
- Support HVAC system validation and performance benchmarking
- Enhance overall IAQ strategies, especially in sensitive environments like schools, hospitals, and commercial buildings
We also combine CO₂ data with additional IAQ metrics, including temperature, humidity, particulate matter (PM2.5), VOCs, and more, to ensure a comprehensive assessment of indoor air quality.
ASHRAE’s 2025 guidance serves as an important reminder: CO₂ can be a valuable tool — when used accurately and interpreted wisely. As industrial hygiene professionals, our responsibility is to ensure that the data we collect is actionable and defensible.
If your team is planning an IAQ assessment or re-evaluating building ventilation performance, SGS can support you with the right tools, technical expertise, and real-time data to guide your decisions.