It has been brought to my attention, dear readers, that I may be a closet pyromaniac. In my fiction writing, my characters are often setting fire to things or watching things burn. You will be relieved to know that, aside from a little mishap when I was seven, I have never actually tried to burn anything down.
But it got me thinking about fire-related words, and I’d like to talk about two of those words: flammable and inflammable. This pair often causes confusion and sometimes leads to heated (if you’ll pardon the pun) arguments.
In an attempt to head off some of those arguments, let me start by telling you that both words mean exactly the same thing. They are both adjectives to describe something that something is easily set on fire.
So why do we have two words that sound like opposites but have identical meanings? That’s a good question.
Inflammable came first. It was a medical term used in the early 1400s that meant something was prone to inflammation. Around 1600, its usage transformed to describe something you could easily set fire to.
Flammable appeared in the early 1800s and has always described something we can easily set on fire.
The big problem with inflammable is that the prefix in-, which comes from Latin, also has two different meanings. One means opposite and the other means in or into. The first meaning is more common but, naturally, inflammable uses the second.
As the usage of flammable caught on, it is said that some good folk out there were concerned that people would get these two words confused and assume that inflammable actually described something that couldn’t be set on fire. In fact, rumour has it that in the 1920s, the National Fire Protection Association campaigned for people to use flammable instead of inflammable, as a concern over fire safety.
So what is the opposite of flammable/inflammable? Another good question. You can choose from several of different words, such as non-flammable, non-combustible, or fireproof.