Children were struck by shrapnel and a man suffered burns to his leg when fireworks malfunctioned at a community fair south of Brisbane last night.

The mishap sent explosives rocketing into patrons at the Jimboomba Family Carnival.

The man who suffered burns to his leg received first aid before being taken to hospital.

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"His trousers got a little bit singed and I think we're buying him a new pair of trousers, probably two," ACE Fireworks operator Robert Stevenson said.

"We're terribly sorry, it never should've happened."

Stevenson, who has been in the fireworks industry for 50 years, said the malfunction was a first.

"The fireworks exploded, obviously the item was faulty," he said.

"The fireworks went close to the fence and it scared everyone, I guess, including myself."

The carnival confirmed on social media that the fireworks show scheduled for tonight would not be going ahead.

Fair organiser Paul Watkins hosed down the drama and apologised for the ordeal.

"It's a misconception, because it was excitement and probably a little bit of scare, but there was no, there was nothing, we've got first aid right there," Watkins said.

"We can only say we're very sorry and hopefully it never happens again."

An investigation is under way by Resources Safety and Health Queensland.

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