ITV did not breach broadcasting rules when Paul O'Grady inhaled helium on his chat show, watchdog Ofcom has ruled.
The Paul O'Grady Show was investigated after its host carried out the prank, which can prove fatal, from a balloon before the watershed, in April.
A spokesperson said: "We investigated this programme to see if it was appropriate to show potentially dangerous behaviour, imitable by children, where the presenter inhaled helium from a balloon.
"We concluded ITV didn't break broadcasting rules because the show has little appeal to children, the presenter's inhalation was very brief and a warning was given.
"We have, however, given guidance to ITV on appropriate scheduling when showing potentially dangerous behaviour."
In March, Dame Helen Mirren sparked controversy when she inhaled helium on US programme The Tonight Show.
The 69-year-old actress took the balloon and chuckled: "I haven't done this since I was about 11. This is the rude bit - suck in - ooh."