- Combustible substances are the substance which burn in air to produce heat and light are called combustible substances.
- Eg :- wood, coal, charcoal, kerosene, petrol, diesel, liquified petroleum gas (LPG), compressed natural gas (CNG) etc.
- Substances like stone, glass, iron nails, etc. do not burn on being exposed to flame. Such substances are called non-combustible substances
- Under the influence of heat, wood produces easily substances that react eagerly with oxygen, leading to the high propensity of wood to ignite and burn.