Police have revised the amount of sulfuric acid a freight train was carrying when it derailed approximately 20kms east of Julia Creek.
Updated information indicates the train was transporting approximately 819,000 litres of sulfuric acid when it derailed on December 27.
An emergency declaration and two kilometre exclusion zone remains in place under the Public Safety Preservation Act to assist emergency services manage the scene, which includes the construction of a safe structure to allow salvage crews access to the crash site.
Assessments to date indicate that one of the carriages has likely ruptured and it is possible that up to 31,500 litres of acid has leaked out.
No other ruptured carriages have been identified as leaking at this stage.
Initial testing by Department of Environment and Heritage Protection to date in the area of the incident, indicates that the nearby Horse Creek waterway has not been adversely affected by any leakage.
It is expected authorities will have teams physically working on site later today dependent on weather.
The Flinders Highway remains closed in both directions between Julia Creek and Richmond as a result of flooding and the exclusion zone.
It is anticipated that the exclusion zone will be in place for least another 48hrs.
The Queensland Police Service continues to work with other emergency services, Queensland Rail, government and industry partners to manage the situation.
Anyone with information which could assist with this matter should contact Crime Stoppers anonymously via 1800 333 000 or crimestoppers.com.au 24hrs a day.
Crime Stoppers is a registered charity and community volunteer organisation working in partnership with the Queensland Police Service.
For all non-urgent police reporting or general police inquiries contact Policelink on 131 444 or Policelink.qld.gov.au 24hrs a day.