Why Use Olive Oil? 
For thousands of years, people have used olive oil as a way to flavor food, but also as a source of light and heat. Among Jews, Eastern Orthodox Christians, and Muslims, olive oil is considered sacred. It is used in many religious rituals and ceremonies as a fuel for lights, lamps, and lanterns.
Olive oil has a very high flash point (190 degrees Celsius for virgin oil, and 210 degrees Celsius for refined oil), which means it does not burn as easily as other vegetable-based oils. Olive oil is also odorless when burned, although you can add other aromatics like herbs to give the burning oil a pleasant scent.
While olive oil used for cooking may be used for lamps, certain grades of oil may be used for lighting purposes:
- Lampanate oils are a grade of olive oil used exclusively for burning. Lampanate oils are not fit for cooking or human consumption.
- Aged oils. Old batches of olive oil can be used for some recipes in the kitchen, but they’re a cheaper source of fuel for oil lamps than extra virgin olive oil. Aged oils also have a higher smoke point.
- Rancid oils. Instead of throwing away rancid batches of olive oil, you can still use it as a fuel for olive oil lamps. The fuel itself may smell bad, but the burning oil will not release any unpleasant smell.