Authorities will consider Port Kembla Copper's evacuation management plan and other vital documents before the postponed stack felling is rescheduled.
The stack was to be demolished in a controlled operation 12 days from now, but the date was deemed "too soon" by the Department of Planning and Infrastructure.
Yesterday a spokesman for the department said the demolition, while given planning approval in 2010, required a number of plans that were still being processed by the government, including a Demolition Management Plan and an Evacuation Management Plan.
"These plans must outline how the demolition will take place, how community safety will be ensured, and how other potential impacts such as dust, noise and vibration will be managed," the spokesman said.
"The plans have now been submitted by PKC, along with other relevant information, and are being reviewed by government agencies to ensure the proposed methods are appropriate and all issues have been properly addressed.
"Once the information provided by PKC has been endorsed, the working group of government agencies will discuss an appropriate date for demolition with the company, NSW Police and emergency services."
The spokesman said the September 5 date was chosen by PKC - "not the government".
He said PKC had lodged more than 100 pages in documentation.
"However, it's likely that additional detail and clarification will be sought by agencies as the review takes place," the spokesman said.
PKC general manager and director Ian Wilson said the September 5 date was set in good faith.
"I believe that we've submitted everything that we should have done at this stage," he said.
The felling method proposed by PKC is designed so the structure will fall on the smelter site itself. Sections to be detonated will be enclosed in a protective covering to stop debris being flung into surrounding areas.