Investigators are on site at Wedderburn to assess the damage caused by a planned hazard reduction burn that got out of control on Saturday.
One smoke-affected firefighter was taken to hospital as a precaution, and a fire truck was destroyed in the fire.
The safety regulator has been notified and investigations into the cause of the incident are ongoing.
An investigation has been launched into a hazard reduction burn in Sydney's south-west that caused the destruction of a fire truck and the hospitalisation of a smoke-affected firefighter.
Conducted by the New South Wales Rural Fire Service, the planned burn at Wedderburn started at 10am Saturday after two successful test fires.
The fire intensified at about 4pm following a sudden change in wind conditions, with the fire destroying one fire tanker and damaging two others.
An RFS volunteer firefighter suffered smoke inhalation and chest pain during the incident and was taken to hospital as a precaution. He has since been released.
Seventeen other volunteer firefighters were assessed and cleared by paramedics.
Additional resources, including two helicopters, were sent to regain control of the fire.
Crews returned to the site on Sunday to continue with damage assessments, with damage reported at two properties.
RFS Commissioner Trent Curtin said the crews activated emergency spray systems on the tankers after becoming overrun by fire.
"Our firefighters are well-trained and they activated their training and their fire protection systems to look after themselves at the time," Commissioner Curtin said on Sunday.
"I understand that some of our crews were away from their tanker at the time that the fire came through, they retreated to a property nearby and admirably undertook firefighting operations immediately after retreating from that area."
Commissioner Curtin said affected volunteers continued to receive support, including from chaplains and incident personnel.
"You can imagine that they are shook up and our crews are concerned about the incident that occurred," he said.
"But what happens is very, very quickly those crews wrap around themselves, they wrap around each other and we provide additional support."
Commissioner Curtin said it was too early to say if the incident could have been prevented, with investigations into the circumstances of the fire ongoing.
"I launched an investigation that will look into all of the factors of this hazard reduction burn to make sure that we can learn everything about what happened yesterday and that we take action to make that these conditions don't happen again," he said.
"There is some risk in undertaking hazard reduction burning, there is risk in firefighting and we'll look into all the elements of that as part of the investigation."
Commissioner Curtin said fire authorities continued to prepare for "what might be a heightened fire risk this bushfire season".
"We've had the driest winter on record, we've got strong El Niño conditions confirmed," he said.
"We know that we're going to see high temperatures and dry conditions through the spring period and that may lead into the summer period.
"Everybody should have a bushfire survival plan, and download the Hazards Near Me app to make sure that they're notified when a fire does occur in their area."
The safety regulator has been notified of the Wedderburn incident.