Key Difference: Flammable and Inflammable have the same meaning. They both refer to products that can easily catch fire. The inflammable is derived from the Italian preposition ‘en’ from ‘enflame’, causing the confusion.

The terms ‘flammable’ and ‘inflammable’ are often seen on various different things such as fabric, chemicals and other certain products. The terms ‘flammable’ and ‘inflammable’ refers to the flammability of the product. The flammability of a product refers to how fast the object will catch on fire. For example, flammability of cotton is higher than denim. Kerosene would be considered more flammable than water, etc. The two words, flammable and inflammable seem the opposite, right? However, it is not. Flammable and inflammable mean the same thing, which means that the product is flammable or it has ability to catch fire fast.

Both the terms actually mean the same thing. I know what you are thinking? How is it possible? In Latin, the prefix ‘in’ actually means ‘un’, meaning opposite of the word that the prefix has been added to. Let’s take the example: discoverable and indiscoverable. In this example, ‘discoverable’ refers to something that can be found, while ‘indiscoverable’ means something that is cannot be found. Similarly, in distinguishable and indistinguishable the term ‘distinguishable’ means it can be differentiated, while in ‘indistinguishable’ means in cannot be.

So, using this example, it should mean that ‘inflammable’ means it doesn’t have the ability to catch fire. However, the term ‘inflammable’ was originally derived from the Latin preposition meaning ‘en’ from ‘enflamed’. Hence, inflammable was used to refer to something that could catch fire. But because of the massive confusion, in the 1920s, the National Fire Protection Association started urging people to shift from ‘inflammable’ to ‘flammable’ to make it less confusing. This gave birth to the two different words.

However, certain products continue to print inflammable on their products rather than flammable, which continues to create confusion. It also doesn’t help that in many languages the word inflammable is the proper word to use for a product that can catch fire. The opposite of inflammable and flammable would be ‘not flammable’ or ‘non-flammable’. This would be printed on a product that will not easily catch fire.

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