Exposure Assessment for Carbon Dioxide Gas: Full Shift Average and Short-Term Measurement Approaches

Area of Science:

• Occupational Health and Safety
• Environmental Monitoring
• Industrial Hygiene

Background:

• Carbon dioxide (CO2) is a common atmospheric gas, but high concentrations can pose health risks.
• Industrial processes using CO2 in gas, liquid, or solid forms can lead to significant airborne exposures.
• Standard 8-hour time-weighted average (TWA) monitoring may not capture dangerous, rapidly fluctuating CO2 levels.

Purpose of the Study:

• To evaluate the effectiveness of fast-responding measurement tools for assessing rapidly fluctuating CO2 concentrations.
• To compare laboratory performance with field applicability of selected CO2 monitoring technologies.
• To document workplace CO2 exposure scenarios and their relation to permissible exposure limits.

Main Methods:

• Laboratory evaluation of colorimetric detector tubes, NDIR, and FTIR instruments using a flow-through system.
• Field deployment of monitoring tools to identify optimal sampling times and locations.
• Combination of real-time monitoring with grab and full-shift sampling for laboratory analysis.

Main Results:

• Colorimetric tubes, NDIR, and FTIR instruments demonstrated suitable accuracy and precision for detecting rapid CO2 fluctuations.
• Humidity potentially affected detector tube accuracy.
• Field studies in breweries, food production, and poultry processing revealed varied CO2 exposure patterns, including brief IDLH exceedances and sustained elevated TWA levels.

Conclusions:

• Fast-responding instruments are crucial for assessing dynamic CO2 exposures and potential immediate dangers.
• Workplace-specific monitoring strategies are necessary to manage risks associated with different CO2 applications.
• Findings confirm the need for robust monitoring to ensure compliance with occupational exposure limits for CO2.