It is now clear that as well as carbon dioxide, Chevron had also intended to inject underground toxic chemicals including BTEX chemicals – benzene (a known carcinogen), toluene, ethylbenzene, and xylene – and mercury. Instead, along with the carbon dioxide it has vented into the atmosphere it has also been venting vapours containing 300 parts per million BTEX and 13,000 micrograms of mercury per cubic metre. It is not known what effect these amounts have had on air quality on the island, with no monitoring results publicly announced, but the Department of Water and Environmental Regulation has flagged “health and safety concerns”. The department has now granted a 12-month approval to Chevron's application to implement a temporary measure: to burn, or ‘flare’, these toxic substances until the carbon injection system is ready – estimated in the document at the second quarter of 2020. While this will take the chemicals further away from the plant workers, to the "ground flare" equipment, and disperse them over a bigger area, reducing their concentration, it does not reduce the overall quantity of mercury being released as elemental mercury cannot be burnt.

Loading In addition, WAtoday understands that over the past fortnight, two separate safety incidents at Gorgon have occurred, potentially exposing workers to chemicals. One involved a vent stack releasing mercury and caused a section of the project to be shut down for several days. The second involved one of the three ‘trains’ transporting gas at the plant, which was accidentally shut down and vented gas. "The documents released today are an embarrassment to Chevron and the state government regulator," Conservation Council of WA director Piers Verstegen said.

"They reveal that the company has no intention or ability to comply with its pollution control conditions any time soon, and instead is scrambling to employ stopgap measures. "It is time WA’s biggest polluter is held to account. The company is being allowed to expose workers and wildlife to toxic chemicals and release millions of tonnes of greenhouse gases. "It is a disgrace and an embarrassment that this company is being allowed to get away with ignoring its conditions of approval, poisoning its own workers, and destroying our future ... if Chevron cannot immediately address its pollution problems, then operations at the Barrow Island LNG facility should be suspended." CFMEU WA secretary Mick Buchan said the union was concerned about both the safety incidents and the venting of gases revealed in the DWER approval. He said Chevron’s direct operations employees were being tested for exposure, but not contractors such as boilermakers, riggers, scaffolders and other maintenance staff.

"We have concerns from workers on that project on what this fallout means for their health," he said. Loading "People in the sector are really unhappy working on those projects." Mr Buchan called on Chevron to work with the union to provide transparent assessments from third-party hygienists for all workers. He also called on Environment Minister Stephen Dawson to make a public statement on what was happening at Barrow Island.

"This is Australia; it is our environment and workers who need to be protected," he said. "If we are serious about workplace health and safety the government needs to shut the bloody plant down until the [carbon sequestration system] is fixed. "We can’t let these multinationals, who pay no tax in this country, get away with this." A Chevron spokesman did not confirm the details of any venting incident or train shutdown. He said Chevron was committed to providing a safe environment for its workforce and as part of routine operations, had extensive monitoring in place to ensure emissions were within acceptable levels.

More than 400 personnel and area samples had been taken over the past quarter, testing for a variety of emissions, none of which had exceeded exposure limits. The carbon injection system was in the commissioning and start-up phase with "strong progress made to date" on system modifications. "Once final system tests were complete, operations would commence, with the first injection planned for later this year. "We are taking the time to start the system carefully and safely as the Gorgon CO2 Injection Project will run for more than 40 years," he said. Environment Minister Stephen Dawson deferred his opportunity to comment to the Environmental Protection Authority, which issued a statement saying the inquiry into the conditions relating to the carbon dioxide injection system was continuing, and when the EPA had finished its inquiry it would provide a report to the Minister.

Department of Mines, Industry Regulation and Safety dangerous goods and critical risks director Steve Emery said the department was aware of "an incident that involved cleaning water and steam being passed to the vent" and the department was "currently investigating the circumstances around this incident". He said the department had not been notified of a Train 1 shutdown event. Oil and gas production is causing Australia’s emissions to rise even as coal pollution drops. Reports last November indicated half of the increase in Australia’s annual carbon dioxide emissions can be attributed to Chevron’s failure to bury the carbon coming out of Gorgon.