Darwin residents are worried about toxic chemicals and gas leaks. We need laws to protect clean air

The federal government is considering enforcement action against oil and gas company Inpex after it admitted serious reporting errors that significantly underestimated hazardous emissions released from its liquefied natural gas (LNG) plant on Darwin Harbour over many years.

The LNG plant is 3 kilometres from residential suburbs and 10km from Darwin city. It is required to report emissions to the National Pollutant Inventory.

Inpex has now released corrections for 2023–24 that more than double the previous estimates of emissions of volatile organic compounds (VOCs) released into the air in Darwin, from 1,619 to 3,562 tonnes. The reason for the errors has not been disclosed.

The originally reported levels of very toxic compounds benzene and toluene were just 4–5 tonnes in 2023–24. However, corrected estimates were 136 and 112 times higher, respectively, with emissions exceeding 500 tonnes of both chemicals.

Currently there is no legal limit on the amount of VOCs that Inpex is allowed to emit. These new figures raise questions about the potential harms, given serious toxicity of benzene and toluene, the large amounts released into the atmosphere over several years, the closeness to population centres and the lack of detail in current sampling. As a cancer-causing chemical, there is no known safe threshold for benzene exposures.

When the news broke, NT Chief Minister Lia Finocchiaro responded with public statements of faith in Inpex and the NT Environment Protection Authority. She said the incident illustrated the reliability of industry self-reporting. Inpex said the revised levels raised no health concerns for Darwin.

As a group of leading scientists aware of the complexities involved in measuring these chemicals and their health impacts, we strongly disagree. We view the potential health implications to be significant – they require an urgent, comprehensive and independent investigation.

Given the size of this correction, it’s imperative that corrections across all years are made public immediately. Corrected levels of benzene and toluene for 2021–22 could be particularly high, as Inpex has already reported emitting 11,000 tonnes of volatile organic compounds to the National Pollutant Inventory. That is nearly seven times more than the amount now reported for 2023-24.

Higher volatile organic compound emissions in 2024/25

In the wake of this scrutiny, Inpex has also released corrected data for 2024–25. Compared with 2023–24, Inpex further increased its emissions of total volatile organic compounds by 21%, with a 31-fold increase in xylene emissions and continuing high emissions of benzene and toluene.

This is despite revelations in 2024 that Inpex had emitted many times more volatile organic compounds than the 500 tonnes predicted in their draft Environmental Impact Statement to the NT government in 2008.

This led to detailed questioning of the chairs of Inpex and the NT Environment Protection Authority by senators David Pocock and Sarah Hanson-Young at the Senate Inquiry into federal support to the Middle Arm Industrial Precinct in Darwin in 2024.

In addition, documents provided by Inpex to the inquiry also revealed the facility’s two anti-pollution devices had been out of operation for extended periods of time since 2019. These devices, called acid-gas incinerators, destroy volatile chemicals such as benzene, toluene and hazardous sulphur-containing compounds before they are released. There were no legal consequences for these breakdowns and resulting elevated VOC emissions.

Alarmingly, the Middle Arm Inquiry Report ignored these discussions. Labor and Liberal senators gave full support for a third LNG facility to be built in Darwin with little mention of the extensive health concerns raised in submissions and additional papers.

Why are these emissions so concerning?

Many studies have linked exposure to the toxic family of chemicals known as BTEX (benzene, toluene, ethylbenzene and xylenes) to multiple health issues. Short exposures can cause symptoms such as headaches, respiratory symptoms and asthma attacks. Longer exposures can cause neurological damage, pre-term births and impaired liver, kidney, lung, reproductive and immune function.

The World Health Organization classifies benzene as a carcinogen, most strongly associated with leukaemia and other blood cancers.

While most research to date has examined risks associated with BTEX chemicals in workplaces and indoor settings, many recent studies have demonstrated that at least some of these risks extend to outdoor exposures.

Last month, an extensive multi-country study demonstrated a consistent link between benzene, toluene and xylene levels in outdoor air and the risk of death.

Besides these direct risks, BTEX chemicals react readily once in the atmosphere to form ground-level ozone, especially in warm, tropical environments such as Darwin.

We need clean air

Darwin residents are understandably concerned about the levels of highly toxic chemicals emitted by Inpex LNG so close to homes and urban areas of Darwin.

Days before these revelations, the NT EPA reported one of Inpex’s two LNG processing units had released 36,000 litres of hot oil across the plant and into stormwater drains.

These pollution issues follow the ABC investigation of a significant gas leak at the nearby Santos LNG facility, which had not been made public for nearly 20 years.

The federal Department of Climate Change, Energy and the Environment is now reviewing these incidents and considering enforcement action.

Inpex senior vice president Bill Townsend told the ABC workers had been told there was “no cause for health concern”, citing air quality monitoring – both on-site and in the Darwin region – which he said had “consistently” shown emissions were within government limits.

This week, hotly debated new national environment protection laws are expected to enter Parliament. Strong environmental laws aren’t just for wildlife – they are vital in protecting human health too. Improved evidence-based federal laws such as a Clean Air Act would go a long way to protecting Australia’s health and wellbeing.