When the shit hits the fan
What's the meaning of the phrase 'When the shit hits the fan'?
'When the shit hits the fan' alludes to the messy and hectic consequences brought about by a previously secret situation becoming public.
What's the origin of the phrase 'When the shit hits the fan'?
This expression alludes to the unmissable effects of shit being thrown into an electric fan. It appears to have originated in the 1930s. I can't say better than 'appears' as, although some usually reliable sources place the phrase in the 1930s, the earliest example of it in print that I know of is in Norman Mailer's novel The Naked and the Dead, 1948:
These riffraff in the platoon had an expression, "to keep a tight ass-hole." What did they know of it? It's the only way they judge anybody, he told himself.
"When the shit hits the fan that's when you keep a . . ."
Mailer brought the phrase to the public's attention but he clearly didn't coin it himself. It was well enough known to the American military for a spoof of it to have been used in a song title in 1946. That's the year that John La Cerda published a memoire of the US war in the Pacific - The conqueror comes to tea: Japan under MacArthur, in which he referred to the song - The Shinto Hit the Fan.
The 1967 edition of Eric Partridge's A Dictionary of Slang and Unconventional English includes this:
"Wait till the major hears that! Then the shit'll hit the fan!"
Partridge lists the phrase as Canadian, circa 1930, but as he gives no supporting evidence we have to go by the 1948 date, although it is undoubtedly earlier, as there are several WWII era citations which have variants of the phrase. These more polite forms of the phrase, which involve eggs, pie, soup and 'stuff' hitting the fan, can certainly be dated from the USA the 1940s; for example, Max Chennault's Up Sun, 1945:
"Sounds like the stuff was about to hit the fan."
The Fresno Bee Republican, May 1948, reported on a psychiatrists' convention, under the heading See How Brain Boys Also Run Wild:
"However, once that opening point was settled, the psychiatrists entered wholly in the business of the convention, which culminated, of course, in the selection of officers for the coming year. And that, as the saying goes, was when the soup hit the fan."
The significance of a phrase in the language can often be measured by the number of variants it spawns. This one perhaps less so than usual as the variants are mostly bowdlerised versions of the explicit original - for example, 'when the solids hit the air conditioning', 'when the pooh hits the punka wallah'.