Equinor Probe Blames MEG Tank Venting for Hammerfest LNG Exposure Incidents

Equinor (EQNR) has concluded that a series of worker exposure incidents at its Hammerfest LNG (HLNG) plant were caused primarily by venting from monoethylene glycol (MEG) tanks, according to a newly released internal investigation. The company said multiple contributing factors—including unusual well-stream conditions, temperature fluctuations, and unanticipated worksite crowding—allowed vented gas to reach ground level, affecting personnel over a one-year period.

The findings bring long-awaited clarity to a sensitive issue that prompted 37 workers to seek medical attention on four occasions between summer 2024 and summer 2025. Symptoms ranged from headaches and nausea to dizziness, though Equinor says the exposures are unlikely to have caused long-term health impacts.

Christina Dreetz, senior vice president for onshore plants, said the investigation underscores gaps in early identification and follow-up after the first exposure event on Melkøya last summer. Insufficient risk assessments before project start-up and poor coordination between the Snøhvit Future project team and HLNG operations contributed to recurrence, she said.

Project activity around area L201, near the MEG tanks, brought more personnel into areas where gas dispersion risk was not fully understood. Regular sampling of vented gas was not conducted, and initial mitigation steps proved inadequate. Measurements conducted later showed generally low concentrations of volatile organic compounds, including benzene, but occasional short-lived spikes.

MEG tanks at Hammerfest LNG are designed to vent a mixture of nitrogen and water vapour from 18–25 meters above ground. However, changes in well-stream composition and temperature resulted in altered gas profiles and noticeable odours. Under certain wind conditions, vented gas descended to ground level, where work crews were active.

Equinor noted that the combination of unusual gas composition, unexpected personnel density, and specific meteorological conditions created the circumstances for the exposures. The investigation found shortcomings in ownership of risk actions, communication between teams, and systematic follow-up.

Equinor reports that recently implemented measures have significantly reduced risk. These include:

• Temporary filtration equipment on MEG tank vents

• Enhanced monitoring, mapping, and regular sampling of vented gas

• Ground-level measurement routines for dispersion assessment

• Updated safety briefings and induction programs for all personnel

• A new local health office at Melkøya

The company says the improved routines allow for earlier detection of dispersion conditions and more effective management of venting episodes.

The investigation report will be submitted to the Norwegian Ocean Industry Authority, which is conducting its own review.

Melkøya hosts the world’s northernmost LNG export facility, with an annual output of 4.6 million tonnes. The plant, operational since 2007, typically employs around 500 people, rising to more than 900 during the Snøhvit Future project period.

Snøhvit Future is intended to secure long-term feed gas through new onshore compression and the electrification of Melkøya. Once completed, electrification is expected to cut annual CO? emissions by 850,000 tonnes, making it one of Norway’s largest single industrial decarbonization projects.

By Charles Kennedy for Oilprice.com

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