Man charged over Sydney Park fireworks

A man has allegedly set off a firework which started a small inner-Sydney fire just days after catastrophic fire danger warnings in the region.

The 34-year-old man before 10pm on Thursday allegedly lit the firework at Sydney Park in St Peters, causing a fire in bushland.

Members of the public prevented the man from leaving the scene and extinguished the blaze before calling authorities.

Police allege the man deliberately ignited the firework to cause a fire, which could have spread rapidly without public intervention.

The St Ives-based man has since been charged with setting fire to property, failing to comply with a total fire ban order and handling explosives.

He'll appear at Central Local Court on Friday.

The alleged incident came soon after a fireworks display on Sydney Harbour was on Thursday evening cancelled due to fire risks around the state.

A display for a corporate event had been planned on Thursday evening on the harbour but did not go ahead after Transport for NSW temporarily banned on-water fireworks amid a week-long state of emergency.

The NSW bushfires have claimed the lives of four people since Friday and damaged or destroyed more than 400 homes.

A separate fireworks display had taken place on Wednesday, drawing ire.

Andrew Howard, director of Howard and Sons Pyrotechnics, said it wasn't his call to proceed with Wednesday's event.

"It wasn't my decision to proceed. I was contracted to provide the services for the event," Mr Howard told AAP on Thursday.

Mr Howard said he would not have gone ahead with the display if it was up to him, knowing the bushfires' "effect on the entire community".

But he reiterated Wednesday's pyrotechnics were lawful, having been granted an exemption from the total fire ban.