Oil lamps - a fire hazard?

[Nathan Ross]

Quick question - if a Roman oil lamp was broken or smashed, would the oil inside it ignite and form a burning pool, or would the oil smother the wick and cause the lamp to go out?

[john m roberts]

Roman lamps burned olive oil. It wouldn't have spread and ignited fast like in the movies. Olive oil has nothing like the volatility of gasoline. A lamp falling against a straw-filled mattress or an old, dry cloth hanging would be much more likely to start a serious fire.

[Nathan Ross]

Thanks! I thought that would be the case, but rather than experimenting with the flammability of olive oil myself I thought it safer to ask here... mile:

Would the oil in the lamp be hot though? If a lamp was thrown against a wall or fell from a high shelf, for example, might the impact increase the volatility of the oil?

[Dan Howard]

Would the oil in the lamp be hot though? If a lamp was thrown against a wall or fell from a high shelf, for example, might the impact increase the volatility of the oil?

No.The only part of the lamp that is hot enough to burn the fuel is the end of the wick and it needs to be combined with oxygen to burn. If you break a lamp the oil will smother the flame and go out, not ignite in a fireball.

[Nathan Ross]

Thanks for the confirmation. As I say, I though the oil would probably smother the flame, but I was sure I'd seen or read something about burning lamp oil starting a fire... Must have been 'artistic license'!

[Dan Howard]

Not olive oil. Petroleum-based fuels tend to ignite more readily.

[Crispianus]

I've used lots of Roman style clay oil lamps, probably as many as 20+ wicks in one go from multi wick lamps and singles, these never heated up to the extent where they became a danger or you couldn't handle them and spilling the vegetable oil would not cause any problem either... on the other hand solid wax/tallow lamps in ceramic holders could cause a fire by getting very hot probably the reason they tend to have a foot...

[Urselius]

The auto-ignition temperature of olive oil is 435 degrees Celsius. If you soaked cloth in olive oil and deliberately set fire to it. it would burn very well, but this sort of thing happening accidentally from an oil lamp accident would be unlikely. I think most building fires in ancient times were caused by cooking, with burning embers getting lodged in dry wood.