Esso has started locking out maintenance workers from its oil and gas plants in Victoria and its offshore platforms in Bass Strait in the latest move in an enterprise bargaining agreement (EBA) dispute.
Unions imposed bans on overtime and call-outs to stop a raft of changes to pay and conditions Esso proposed.
The lockouts affect the Longford gas plant, Long Island Point and Esso's oil and gas plants in Bass Strait. The maintenance workers will be locked out for two hours a day.
Peter Mooney from the Electrical Trades Union said the lockouts would delay important maintenance work and could raise safety issues.
He said workers had voted overwhelmingly in secret ballots against Esso's proposed changes.
"We've had no meetings where there's been any opportunity to progress with the unions and the company," he said.
"The company is taking the position that it will continue to press with its claims which are untenable to our members."
In June Ben Davis from the Australian Workers Union said, "We think that cutting employee numbers onshore presents all sorts of safety hazards both at Long Island Point and at Longford and offshore."
"It's the age old debate about seven on, seven off versus 14 and 14 rosters.
"Now employees offshore, members offshore, have told Esso they're not interested in the 14 and 14 roster."
In July 2001, Esso was fined a record $2 million in the Supreme Court after being found guilty of 11 charges under the Occupational Health and Safety Act.
Esso Longford gas plant explosion 1998
In 1998 the Esso Longford gas explosion was a catastrophic industrial accident which occurred at the Esso natural gas plant at Longford in the Australian state of Victoria's Gippsland region. On 25 September 1998, an explosion took place at the plant, killing two workers and injuring eight. Gas supplies to the state of Victoria were severely affected for two weeks.
Professor Andrew Hopkins examines the eleven key contributory elements in the safety chain, and flags these in a generic way so that participants in the safety training DVD workshop can apply the same approach to their own organisations.
Preventing Disaster: Learning from Longford DVD workshop.
Lessons from Longford: The Esso Gas Plant Explosion book by Professor Andrew Hopkins.