Carbon Monoxide Detectors, Rent or Buy

When is continuous carbon monoxide (CO) monitoring better than spot checks?

Use continuous monitoring during active work (running equipment, changing ventilation, varying traffic) because CO can spike quickly. It's also better when you need time-stamped documentation rather than a single snapshot.

Where should a carbon monoxide (CO) monitor be worn or placed?

For personal exposure assessment, CO monitors should be worn in the breathing zone—clipped to the collar or lapel. For area monitoring, place units at breathing zone height (approximately 5 feet) in representative locations where workers spend time. Avoid placing monitors directly in front of exhaust sources or near ventilation inlets, which would give readings unrepresentative of worker exposure. In vehicles, mount at occupant breathing zone level, not at floor level where CO from exhaust is highest.

Should I use a CO-only monitor or a 4-gas monitor?

Use a CO-only monitor when CO is the known primary hazard. Use a 4-gas monitor for confined spaces or unknown atmospheres where O₂ deficiency, flammables (LEL), or H₂S may also be risks—many jobs need more than CO alone.

Can I rely on symptoms to warn me about carbon monoxide exposure?

No. CO symptoms (headache, dizziness, fatigue) are non-specific and may be absent at dangerous concentrations. Never use how you feel as the sole CO indicator—use a calibrated CO monitor.

When should I use a CO monitor on a jobsite?

Anytime combustion sources are present or could accumulate: generators, propane equipment, internal combustion engines, or enclosed/semi-enclosed spaces where exhaust may build up.

What should I confirm before renting CO monitors?

Confirm your alarm setpoints, whether you need personal monitors, area monitors, or both, and whether CO is the only hazard or whether O₂/LEL/H₂S coverage is also needed.