On 21 August 1991 at approximately 2.17 pm, an explosion occurred on Coode Island in Melbourne when a 600,000 litre chemical storage tank filled with acrylonitrile exploded and caught fire. The fire burned various hazardous chemicals including acrylonitrile, phenol, methyl ethyl ketone and benzene forming clouds of potentially toxic black smoke up to 30 km from the site, prompting the evacuation of Footscray Primary School, nearby buildings and ships, and closure of roads. People were advised to stay inside with windows and doors closed to avoid smoke inhalation. Testing conducted later showed that the smoke was not a chemical hazard due largely to the heat of the fire and high winds helped to dissipate the smoke from the area.

It took 155 firefighters approximately three hours to gain control of the fire and two were injured in the process. The following morning at approximately 11.45 am, a ruptured pipeline caused an explosion in another storage tank that sent a fireball into the sky. This fire spread to four other storage tanks and burned until control was gained at around 4 pm. Fire fighting efforts alone were estimated to cost $2 million as the fire control required large quantities of foam.

In total, approximately 16 chemical storage tanks were damaged or destroyed, with approximately 8.6 million litres of chemicals burnt and more leaking.

A Coronial Inquest was in 1994 found that on the balance of probabilities a corona discharge occurred, igniting the chemicals within Tank 80. A corona discharge, colloquially known as ‘St Elmo’s fire’, is akin to lightning, but in slow motion and with a much lower discharge of energy. The Coroner praised fire fighters and other emergency service personnel for their efforts in the response.

Damage and clean-up costs were later assessed at between $20 and $35 million. The owner of the facility was charged under environment protection and labour laws with the penalty imposed in the vicinity of $1.3 million. According to the Financial Review the owners held an insurance cover of $20 million which covered the replacement value of the facility in addition to public liability insurance. Therefore, the insurance cost of Coode Island is assessed as $21.3 million.