Equinor has completed its internal investigation into an incident on 29 October 2025, in which personnel at Mongstad were exposed to chemicals. The incident occurred during work on a measuring instrument. A number of measures have been implemented to capture lessons learned.
On 29 October, activity at the Mongstad refinery was high. The plant was preparing for start-up following an extended maintenance shutdown, and as part of this work, a team was assigned to troubleshoot and fill naphtha into a measuring instrument. The task was expected to take around 30 minutes but lasted for more than five hours. Re-evaluation of risk was not performed and led to prolonged exposure. Two employees experienced discomfort afterwards, and one of them was absent from work for a brief period.
“We take this incident very seriously. Everyone shall be safe when working at the plant, and we work every day to ensure this through the planning, execution and follow-up of our operations. After the incident naphtha has been replaced with glycol, which does not emit benzene, in this type of measuring instrument. The report provides us with clear insight into the causes of the incident and lessons to incorporate into our ongoing improvement work at Mongstad, together with employees, the safety service, suppliers and authorities,” says Bernt E. Tysseland, vice president at Equinor Mongstad.
Causes of the incident
The investigation report points to several factors that contributed to the incident. Staff worked in an area with elevated benzene levels for several hours, and the respiratory protection selected did not provide adequate protection in this situation.
In addition, issues relating to the management of the chemical environment are highlighted, and the ramp-up phase after the maintenance shutdown involved high activity and perceived time pressure. This affected the planning and risk assessment prior to the work. No new risk assessment was conducted when the job took longer than planned. Furthermore, the review identified areas for improvement related to the introduction of an updated respiratory protection regime.
Measures to strengthen risk management
Following the incident, several measures have been introduced to strengthen risk management in relation to the chemical working environment at Mongstad. These include enhanced compliance with the protection regime, increased availability of respiratory protection, and further training in the use of benzene and gas detectors. To ensure stronger professional support in the field, a dedicated safety engineer has been assigned to work on improving the chemical working environment at the facility.
The incident is reported to the police by the Norwegian Ocean Industry Authority who will both receive the report from Equinor.
