A firefighter who patrolled Morwell's streets testing for carbon monoxide during the Hazelwood mine fire has revealed the 'safe' CO threshold was altered by authorities during the event.
A report from 'Firefighter L', a leading firefighter in the Metropolitan Fire Brigade of 12 years, outlined instructions given to his team in what they could and could not say to residents during the fire.
Initially, the firefighter and his team worked with the time weighted average of 30 parts per million as a trigger point for alerting the community that carbon monoxide levels were dangerous and protective equipment must be used to stay in the environment.
Soon after, the firefighter was informed that 70ppm would be the new trigger point for warning the community.
The Department of Health officials had called for the change, according to the firefighter's statement.
"Concern had been expressed about this new figure as it exceeded levels in which firefighters were required to wear breathing apparatus and yet the health department were allowing the public to be exposed to those levels," the statement read.
In addition to this change, the firefighter also reported he and his team were told on 25 February not to give any recommendations to residents, including whether or not they should relocate.
"We were told to say that 'we were Hazmat technicians doing air monitoring in the township', that is all," the statement read.
Firefighter L stated the team chose to loosely advise the public based on their readings to fulfil their duty to protect life and property.
"So when the levels got dangerous we advised the public that perhaps it was not the best environment for them to be in and suggested that if possible they should try and remove themselves from the environment," the statement read.
United Firefighters Union president Peter Marshall has called on the Hazelwood Mine Fire Inquiry board to promise protection for career firefighters, who he said had been threatened with punitive action if they spoke up.
"We want the Premier to guarantee the firefighters are able to speak out on public safety issues without the threat of dismissal or other punitive action," Mr Marshall said.
"They were gagged down in Morwell from telling the community anything and they've also been gagged from submitting to the inquiry."
Mr Marshall said beyond 50ppm, firefighters were required to wear breathing apparatus and if levels reached 75ppm, they were evacuated.
"There was no information provided to the community on these figures, there's no rationale from raising it from 30 to 70," he said.
"Serious questions need to be asked and answered as to why the firefighters' concerns were not acted upon and why they were silenced from informing the community."
Following the statement's release, Voices of the Valley president Wendy Farmer called for the resignation of Chief Health Officer Rosemary Lester and Health Minister David Davis.
"We're angry, annoyed and frustrated; our community should not have been treated like this," Ms Farmer said.
The Express contacted MFB but received no response at the time of print, while the CFA issued a statement saying "the appropriate forum for these allegations to be put and tested is the Commission of Inquiry".
The Victorian Department of Health was also contacted and issued a statement saying "these are matters that should be put before the board of inquiry, that's the appropriate place for it to be further examined".