Flammable vs Combustible
Combustion or heating is a reaction where heat is produced by an exothermic reaction. Combustion is an oxidation reaction. For a reaction to take place, a fuel and an oxidant should be there. Substances undergoing the combustion are known as fuels. These can be hydrocarbons like petrol, diesel, methane, or hydrogen gas etc. Usually the oxidizing agent is oxygen, but there can be other oxidants like fluorine too. In the reaction, the fuel is oxidized by the oxidant. So this is an oxidation reaction. When hydrocarbon fuels are used, the products after complete combustion are usually carbon dioxide and water. In complete combustion, few products will be formed, and it will produce the maximum energy output that the reactant can give. However, for complete combustion to take place, unlimited and constant oxygen supply, and optimum temperature should be there. Complete combustion is not always favored. Rather incomplete combustion takes place. If the combustion does not happen completely, carbon monoxide and other particles can be released into the atmosphere, which can cause a lot of pollution.
The categorization of substances to flammable or combustible depends on the flash point. The flash point of a liquid is the lowest temperature at which the liquid starts to burn. At this point, the liquid gives off enough vapors to be ignited. Flammability and combustibility of a substance is something important to be taken into consideration. Especially in the construction fields, it is necessary to know these properties of a substance. Almost all the workplaces have combustible or flammable substances like fuels, solvents, cleaners, adhesives, paints, polishes, thinners etc. Therefore, people should be aware of their hazards and how to work safely with them.
Combustible means the capability to catch fire. Combustible substances have a flash point at or above 37.8°C (100°F) and below 93.3°C (200°F). If a substance has a low combustibility, it is hard to catch on fire. However, if a substance is more combustible, then safety precautions should be taken when handling it. Diesel, Kerosene, and Vegetable oils are some examples for combustible liquids.
Flammability is also a measurement of how quickly the things will ignite. Flammable substances easily catch fire. Flammable liquids have a flashpoint below 37.8°C (100°F). Gasoline, kerosene, propane, natural gas, butane, and methane are some of the flammable substances. A fire test can be conducted to check the level of flammability of a substance, and based on the information, substances are rated.
What is the difference between Combustible and Flammable?
• Combustible substances have a flash point at or above 37.8°C (100°F) and below 93.3°C (200°F). Flammable substances have a flashpoint below 37.8°C (100°F).
• Flammable substances catch fire quicker than combustible substances.
• Combustible substances emit more heat than flammable substances.