What is the flammable range for heating oil?

The flammable range of a substance refers to the concentration of vapor in air that can ignite if an ignition source is present. For heating oil, the correct flammable range is between 1% and 6% by volume in air. This range indicates that heating oil must be present in enough concentration to form a combustible mixture with air to pose a fire risk.

Outside this range, there is either too little or too much heating oil vapor for a flame to propagate. Understanding this range is crucial for ensuring safe handling and storage of heating oil, as it helps in assessing risk and implementing safety measures in environments where heating oil is used. This information is particularly important for compliance with safety regulations and for reducing the likelihood of fire hazards associated with underground storage tanks.