An iconic 22-storey copper chimney in Wollongong has fallen in a controlled explosive demolition, providing a spectacular show for onlookers.

Explosives were set off around the Port Kembla copper stack around 11.15am on Thursday.

Spectators cheered and clapped as the tower began to lean then fall, leaving a huge cloud of smoke and dust around the area.

Emergency services, including a police helicopter, assisted the operations which forced the evacuation of all residents within a 300-metre radius.

Some residents had been concerned that the 49-year-old tower had not been properly assessed for asbestos and the demolition could threaten locals with dangerous toxins.

An attempt to stop the demolition by Wollongong City councillor Vicki Curran on Monday was unsuccessful.

Port Kembla Copper will wet down the area in an attempt to stop dust from spreading.

Teams of inspectors are reportedly checking the exclusion zone for contamination before allowing residents to return.