A sooting lamp is burning its fuel incompletely, which wastes fuel and also makes carbon monoxide, a gas with no colour or smell. Fix it in order: lower the wick, trim it, choose a cleaner fuel, then ventilate the room with an opening to let air in and a second opening to let it out. A single cracked window is not enough.
Part of Oil Lamp Construction
Soot is unburned fuel, so a sooting flame is burning incompletely and making carbon monoxide. Clean air in a room needs an opening to let air in and a second to let it out.
A Lamp Flame Should Be Steady, Not Smoking
Oil flames glow yellow because tiny carbon particles in the flame heat up and shine. That yellow glow is normal in a lamp. What is not normal is a flame that sends up a dark trail, deposits black on a chimney or reflector, or leaves soot on the ceiling. That means fuel is escaping unburned, and where combustion is incomplete, carbon monoxide forms.
The overview says all oil lamps produce some soot, especially with animal fat, and ranks the fuels:
| Fuel | Soot |
|---|---|
| Olive oil, kerosene | Least |
| Fish oil, crude tallow | Most |
Fix Soot In This Order
- Lower the wick. The overview says heavy black smoke means the wick is too high.
- Trim it. See Wick Trimming.
- Change the fuel. Use a cleaner, better-strained fuel.
- Add a chimney if the lamp can take one. See Glass Chimneys.
- Ventilate.
Ventilate With An Inlet And An Outlet
Moving air out is only half the job: air must also come in. Open one opening low on one side of the room to let fresh air in, and another higher up on the opposite side to let warm air and combustion gases out, so that air moves across the room. One cracked window mostly swaps air back and forth through the same gap and gives poor exchange. Do not rely on the common advice that one small opening is enough: a lamp in a small room is a continuous source of combustion gas, and a single gap cannot be relied on to clear it.
Wipe soot from walls and ceilings now and then; the overview notes that it builds up and is combustible.
Common Mistakes
- Closing the room to keep it warm while the lamp burns. That removes the fresh air the flame uses.
- Opening only one window. Provide an inlet and an outlet.
- Treating headache or drowsiness as just tiredness. Near a burning lamp, it may be carbon monoxide.
Safety
Carbon monoxide has no smell and its first symptoms feel like tiredness
Carbon monoxide is odourless and colourless. Headache, nausea and drowsiness are exactly what a cold, tired person expects to feel anyway, which is why it kills people indoors. If anyone feels sleepy near a burning lamp or stove, that is a reason to put the flame out, open both ventilation openings and get everyone into fresh air, not to lie down. Do not use a flame to test the air: a flame burns normally at concentrations that kill. Never sleep in a closed room with a burning lamp.
What’s Next
- Learn next: Carbon Monoxide Risks — the hazard in more detail, with numbers
- Combine with: Fire Prevention — the other lamp hazard