Inflammable & Flammable

Inflammable (pronounced in-flam-uh-buhl)

(1) Easily set on fire; combustible; incendiary, combustible, inflammable, burnable, ignitable (recommended only for figurative use).

(2) Easily aroused or excited, as to passion or anger; irascible; fiery; volatile, choleric.

1595–1605: From the Medieval Latin inflammābilis, the construct being the Classical Latin inflammā(re) (to set on fire) + -bilis (from the Proto-Italic -ðlis, from the primitive Indo-European i-stem form -dhli- of -dhlom (instrumental suffix).  Akin to –bulum, the suffix -bilis is added to a verb to form an adjectival noun of relationship to that verb (indicating a capacity or worth of being acted upon).  The construct of the Classical Latin inflammare (to set on fire) was -in (in, on) + flamma (flame).  As an indication of shifts in use, the verb inflame & noun inflammation are now most commonly used in clinical medicine to describe swellings, a site especially "reddish" often called "angry".  Inflammable is a noun & adjective, inflammation, inflammableness & inflammasome & inflammability are nouns, inflammatory is an adjective and inflammably is an adverb; the noun plural is inflammables. 

Flammable (pronounced flam-uh-buhl)

Easily set on fire; combustible; incendiary, combustible, inflammable, burnable, ignitable (technically a back-formation from inflammable).

1805–1815: From the Classical Latin flammā(re) (to set on fire) + -ble (the Latin suffix forming adjectives and means “capable or worthy of”).  Flammable is an adjective, flammability is a noun and flammably is an adverb; the noun plural is flammabilities.

Google ngram (a quantitative and not qualitative measure): Because of the way Google harvests data for their ngrams, they’re not literally a tracking of the use of a word in society but can be usefully indicative of certain trends, (although one is never quite sure which trend(s)), especially over decades.  As a record of actual aggregate use, ngrams are not wholly reliable because: (1) the sub-set of texts Google uses is slanted towards the scientific & academic and (2) the technical limitations imposed by the use of OCR (optical character recognition) when handling older texts of sometime dubious legibility (a process AI should improve).  Where numbers bounce around, this may reflect either: (1) peaks and troughs in use for some reason or (2) some quirk in the data harvested.

Need for standardization

Flammable and inflammable came to the same thing.  English, a mongrel vacuum-cleaner of a language, has many anomalies born of the haphazard adoption of words from other tongues but the interchangeability of flammable and inflammable is unfortunate because of the use in signs to warn people of potentially fatal danger.

Using flammable and inflammable to mean the same thing is confusing and at least potentially dangerous and the recommended use is flammable (things prone to catching fire) and non-flammable (things not).  To add another layer of meaning less language-dependent, borrowing from semiotics, danger should be indicated with red, safety with green.

In- often is used as a prefix with adjectives and nouns to indicate the opposite of the word it precedes (eg inaction, indecisive, inexpensive etc).  Given that, it would seem reasonable to assume inflammable is the opposite of flammable and the reason for the potentially deadly duplication is historic.  Inflammable actually pre-dates flammable, the word derived from the Latin verb inflammare (to set on fire), this verb also the origin of the modern meaning “to swell or to provoke angry feelings”, hence the link between setting something on fire and rousing strong feelings in someone.  So, at a time when Latin was more influential, inflammable made sense.  However, as the pull of Latin receded, words with in- (as a negative prefix) became a bigger part of the lexicon and the confusion was created; by early in the 1800s, flammable increasingly came to be used and in the next century, as the use and storage of flammable substances grew, use was widespread.  The modern convention is (or should be) to use flammable literally (to refer to things which catch fire) and inflammable figuratively (to describe the arousal of passions, the swelling of tissue etc.  Surprisingly, the rules applying to warning signs have yet to adopt this standardization.

The Mean Girls (2004) Burn Book (left) and Lindsay Lohan burning an “inflammatory” tabloid magazine, Lindsay Lohan: The Obsession, GQ Magazine, October 2006.

Uses figurative and literal: In Mean Girls, the Burn Book gained its notoriety from being packed with inflammatory comments.  Lindsay Lohan in 2006 picked up the concept in a photo-shoot by Terry Richardson (b 1965) for GQ (Gentlemen's Quarterly) magazine.  Titled Lindsay Lohan: The Obsession, the theme was her as a case-study of the way “tabloid publications” handled celebrity culture, the joke being a magazine with “inflammatory content about her” being literally set aflame, the glossy paper of course being flammable.  It’s appears a consensus in the “media studies” crew that this aspect of “tabloid culture” peaked in the first dozen-odd years of the twenty-first century, the reasons for that including (1) the period having an exceptionally large cast of suitable subjects, (2) smart phones with HD (high-definition) cameras becoming consumer items meaning potential content proliferated (ie what once would not have been photographed now became available to editors as low cost images) and (3) social media sites not having attained critical mass, all factors which at the time enabled the lower-end glossies to flourish.

1972 Ford Ranchero 500 (left) and a circa 1972 Ford Pinto (right).

“Hot Rod Flames” first became popular when the West Coast hot rod community began adding them to their modified machines.  Rendered usually in red, orange and yellow to emulate actual flames, in the decades since they’ve appeared in many colors, sometimes in hues which would never be seen in nature and they’re now a commodity with templates and adhesives widely available; the motif was also picked up by the tattoo community.  Traditionally, when applied to a hot rod or other modified vehicle, the placement of the lick of the flames was quasi-realistic in that the effect was intended to be that of a flaming car in motion.  One widely circulated image however was of a Ford Pinto (1970-1980) with the flames travelling “the other way”: from the back towards the passengers.  The artwork was a sardonic comment on the Pinto’s reputation for bursting aflame if struck from behind by another vehicle, the allegation being Pintos were unusually flammable (the media tended to prefer the more dramatic “explosive”) in such cases because of the placement of the gas (petrol) tank and design of the fuel system.  In truth the Pinto’s susceptibility probably was little different from that of many other vehicles with a similar layout but what gained the modest machine notoriety was the discovery of “inflammatory” comments in internal corporate memorandum in which executives discussed the relative costs of rectifying the problem compared with the likely costs of legal settlements compensating incinerated victims and their families.