Trending: Everything the First Lady needs to know about gunge

Singer Justin Bieber is slimed on stage at Nickelodeon's 25th annual Kids' Choice Awards in LA (Reuters)

This weekend's 25th annual Nickelodeon Kids' Choice Awards saw Justin Bieber, Halle Berry, Will Smith, Taylor Lautner and Chris Colfer of Glee inducted into a very select group of celebrities. No, not the winners of the "Favourite Buttkicker" gong (though Lautner did win that one), but that privileged élite blessed with having been "slimed" on TV.

Even Michelle Obama was part-spattered with the green stuff that, in the UK, we tend to call "gunge". The substance consists of water mixed with an industrial thickening agent (hydroxyethylcellulose is popular in the UK, methylcellulose in the US) and a colourant such as powder paints or food colouring (powder paints are less likely to leave a stain on designer clothing). Gunge/slime was a regular feature of BBC programmes such as Tiswas, Noel's House Party and Dick and Dom in the Bungalow.

In North America, it had a starring role in the Ghostbusters movies, and has long been a favourite prank-based tool for Nickelodeon, the children's channel whose very logo is a blob of orange slime. An honour indeed.