Carbon dioxide gas is about 1.5 times heavier than air, so it often collects in low-lying areas. Cellars, basements, trenches, sumps, and walk-in cold rooms are common locations where carbon dioxide may increase, particularly after leaks from pressurised systems or during the use of dry ice.

Hiring allows you to deploy additional monitors quickly without committing to purchasing permanent equipment. Instruments from Ribble Enviro are supplied fully calibrated and ready for use.

When Is Carbon Dioxide Gas Monitoring Required?

Carbon dioxide monitoring is typically required wherever CO₂ might be released or accumulate. The risk is higher in confined spaces, below-ground areas, and locations using pressurised CO₂ cylinders, distribution lines, or refrigeration systems.

Monitoring also plays an important role during entry, inspection, cleaning, and maintenance work, when gas levels may change quickly.

In Great Britain, workplace exposure limits are defined in HSE guidance EH40/2005. The limit for CO₂ is 5,000 parts per million averaged over an eight-hour reference period, with a short-term limit of 15,000 parts per million over fifteen minutes. Monitoring equipment is used to check everyday exposure and identify short-term peaks.

Carbon dioxide must be measured directly. Acceptable oxygen readings alone do not confirm that CO₂ concentrations are not present or within safe limits.

Typical carbon dioxide monitoring applications

Carbon dioxide monitoring is commonly required in the following locations:

• Cellars, basements, and below-ground filling stations where CO₂ may settle
• Breweries and fermentation areas, including tank cleaning and maintenance work
• Beverage dispensing and carbonation systems using pressurised cylinders and pipework
• Walk-in coolers and cold storage areas using CO₂ refrigeration systems
• Confined spaces such as sumps, trenches, and vessels where gas may accumulate
• Dry ice storage or handling areas where sublimation increases CO₂ levels
• Rooms protected by CO₂ fire suppression systems following a discharge event

Monitoring carbon dioxide in these environments helps prevent potentially lethal accidents while work is ongoing.

Which Carbon Dioxide Monitor Should I Hire?

Air movement, occupancy levels, and nearby combustion processes can all affect how carbon dioxide concentrations vary within a working environment. These variables can cause inaccurate readings when equipment is not positioned correctly or poorly maintained.

Ribble Enviro keeps a fleet of well-maintained carbon dioxide detector hire equipment and can advise on monitoring strategies to help organisations have effective oversight of workplace CO₂ levels.

NDIR CO₂ instruments for workplace monitoring

For workplace safety, non-dispersive infrared (NDIR) sensing is the industry standard for CO₂ measurement. These sensors provide accurate, real-time readings. They are suitable for leak detection and monitoring ventilation performance in places where concentrations may rise significantly.

NDIR sensors require periodic calibration to manage baseline drift. Instruments commonly used for carbon dioxide monitoring include the RAE Systems ToxiRAE Pro CO₂ and the GasData GFM436.

The difference between personal and area monitoring

Personal monitors are useful when workers move between different locations or operate near potential leak sources. Area monitoring is often used when continuous readings are needed in fixed locations where CO₂ may collect, such as plant rooms or cellar spaces.

In environments where additional atmospheric hazards may exist, a multi-gas instrument may be used alongside carbon dioxide monitoring. Instruments such as the BW RigRat or the Crowcon Gas-Pro can be configured with multiple sensors depending on the hazards present.

Spot checks and continuous monitoring

Single-point measurements can provide a quick indication of conditions during initial checks. However, they do not provide continuous information or warnings when gas levels change. For higher-risk tasks, continuous monitoring usually provides a more reliable picture of exposure conditions.

If you are planning work in areas where carbon dioxide may accumulate, the Ribble Enviro team can help you select the most suitable carbon dioxide detector hire based on the environment and monitoring requirements.