Federal government agency Airservices Australia has rejected calls from a key firefighters union for the release of records related to the use of foams containing toxic chemicals.
The aviation branch of the United Firefighters Union last week called on the organisation to make public information denied under freedom of information laws, amid ongoing controversy about contamination from foam widely used at 26 airports across Australia.
The foams, used between 1980 and 2003, contained harmful polyfluoroalkyl substances.
Known as PFAS, the products were used by government-employed firefighters at dozens of airports and military bases.
The Environment Department has previously described the chemicals as "persistent, bioaccumulative and toxic".
Union aviation branch secretary Henry Lawrence said Airservices Australia had blocked requests for information on the nature and extent of PFAS contamination and the risks posed to aviation firefighters and the community.
Warning signs were placed at a Gold Coast beach last week after local council officers found traces of PFAS chemicals in a nearby waterway and Queensland and NSW cattle farmers near the Oakey and Williamtown Defence bases have raised concerns they could be selling contaminated meat.
PFAS contaminations have been located at several airports, including Gold Coast airport at nearby Coolangatta.
ABC TV outlined concerns about PFAS contamination around 18 Australian Defence Force bases across the country this month.
"We were deeply disappointed that Airservices Australia blocked the union's freedom of information requests on PFAS contamination at 26 airports across Australia, no less than four times," Mr Lawrence said.
The union released photos taken during aviation rescue and firefighting training exercises involving the foam at Melbourne's Tullamarine airport in 1998.
"Airservices must understand that the time for obfuscation has passed. It's time to come clean on PFAS contamination," he said.
The first preliminary site tests identified possible PFAS contamination at Canberra Airport's old fire fighting training ground in 2008.
Further investigations found PFAS residues in the soil and groundwater around another site at the airport's fire station.
The airport site was leased from the Commonwealth in 1998 when little was known about PFAS risk.
Major airports including Sydney, Gold Coast, Perth, and Brisbane are either known or thought to be affected by PFAS contamination.
This week, Airservices Australia said it had not used a fire fighting foam containing PFAS at any of 24 civilian airport operations across Australia since 2010.
The organisation began phasing out foams containing PFAS in the early 2000s.
"This is a legacy issue and we are continuing to assess the impacts from the historical use of fire fighting foams containing PFAS," the spokeswoman said.
"Airservices is committed to working with our staff, airports and relevant federal and state government agencies to further investigate the possible human and environmental impacts associated with the historical use of fire fighting foams containing these chemicals.
"We will take whatever action is required by regulators or our own investigations to minimise any risks as a result of past use of these foams."
An Airservices spokeswoman said the union's request was "so broad ranging it was unreasonable to action under the FOI process.
"We have formally offered the UFU a face-to-face briefing on the subject a number of times in recent months to better understand its concerns, to which we are yet to receive a response. This offer still stands."
PFAS was confirmed at Sydney, Gold Coast, Perth and Brisbane airports in 2007 and 2008 testing. Site investigations are currently under way to determine potential off site migration at each location.