Carbon Monoxide in Winter Heating
29 CFR 1926.154 · 29 CFR 1926.55 · This talk in Spanish
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Why it matters
Cold-weather work brings heaters into enclosed spaces, and fuel-burning heaters bring carbon monoxide. A heater in a sealed basement or a building wrapped in plastic can fill the space with CO before anyone notices. OSHA has rules for temporary heating devices, and the first one is fresh air. Today we make sure staying warm does not become the most dangerous thing we do.
Hazards
- ⚠ Fuel-fired heaters consuming oxygen and producing CO in tight spaces
- ⚠ Buildings wrapped in poly holding exhaust like a bag
- ⚠ Heaters running overnight, filling the space before the crew arrives
- ⚠ Poorly maintained burners producing far more CO than rated
- ⚠ CO stacking from heaters plus generators plus equipment
- ⚠ Morning headaches blamed on the cold instead of the heater
Controls and safe practices
- ✓ Ventilate per 1926.154: fresh air supply sized to the heater, not just cracks and gaps.
- ✓ Prefer indirect-fired heaters (burner outside, ducted heat inside) for enclosed areas.
- ✓ CO monitors in every heated enclosure, checked at shift start, especially first thing in the morning.
- ✓ Maintain heaters: clean burners, correct fuel, and inspection before the season.
- ✓ Keep heaters level, on noncombustible surfaces, with clearances per the label.
- ✓ Test the atmosphere before entering enclosures where heaters ran unattended.
- ✓ Symptoms drill: headache, nausea, confusion means everyone to fresh air, count heads, call for help.
Crew discussion questions
- What heaters are we running this winter, direct or indirect fired?
- How does fresh air actually get into our heated areas?
- Who enters heated enclosures first in the morning, and do they check the monitor?
- When were our heaters last serviced?
Applicable OSHA standards
29 CFR 1926.154, 29 CFR 1926.55
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