Inflammable versus Flammable: Inflammable Got Burned

There is a small family of words with negating suffixes that mean the same thing as the related word. They seem like they should be opposites, but they are synonymous. (De)bone, (in)valuable and (de)press come to mind, but the king of all of these is flammable, whose counterpart, inflammable, means exactly the same thing. The story behind the two words is fascinating.

In saying they are related, first understand they are related as cousins rather than brothers. Both flammable and inflammable derive from Latin words relating to burning, but the precise words each derive from are different. Inflammable was by far the more popular of the two English derivations through the 19th and into the early 20th century.

The industrial revolution was in full swing and early 20th century user documentation and marketing materials sometimes presented the term inflammable incorrectly in describing a product’s potential combustibility, and anecdotal evidence of some consistent misreading of inflammable having inspired user carelessness was in the ether. 

Insurance companies and safety experts took notice and launched a campaign urging authors, attorneys, physicians, newspaper writers and others to begin using flammable instead to avoid potentially confusing people with something that could cause injury and property damage. The following notice was commonly found in technical journals in the early 1920s:

 

"The National Safety Council, The National Fire Protection Association, and similar organizations have set out to discourage the use of the word inflammable and to encourage the use of the word flammable instead. The reason for this change is that the meaning of inflammable has so often been misinterpreted."

Flammable indeed is the dominant usage now, though when the directive first began to be adopted, the academics howled at the injustice, perfectly happy to let the hoi polloi burn in their own ignorance. Both remain permissible by modern editorial standards.

So what does the future hold for inflammable? As language in general tilts more and more toward the utilitarian and away from the bejeweled, I suspect that flammable has won the battle once and for all by virtue of conserving a syllable and two characters in a tweet, and that inflammable’s flame will flicker and fade further and though not die out entirely, before long become solely the province of sophists and hidebound doctrinaires. It sounds pretentious to my ear and I recommend against it in favor of flammable.